فهرست مطالب

تنشهای محیطی در علوم زراعی - سال سیزدهم شماره 2 (تابستان 1399)
  • سال سیزدهم شماره 2 (تابستان 1399)
  • تاریخ انتشار: 1399/03/25
  • تعداد عناوین: 25
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  • پروانه لطیفی، عبدالله نجفی*، لیلا زارعی صفحات 319-329

    اثر متقابل ژنوتیپ × محیط باعث ایجاد پیچیدگی در پیش بینی عملکرد می شود و چالشی برای برنامه های به زراعی و به نژادی است. هدف از این تحقیق بررسی اثر متقابل ژنوتیپ × محیط و مطالعه سازگاری و پایداری عملکرد 21 ژنوتیپ جو با استفاده از تجزیه مدل اثرات اصلی افزایشی و ضرب پذیر (AMMI) می باشد. آزمایش حاضر در قالب طرح بلوک های کامل تصادفی در دو تکرار طی سال های زراعی 94-1393، 95-1394، 96-1395 در دو شرایط دیم و آبی (در مجموع شش محیط) اجرا شد. نتایج حاصل از تجزیه واریانس مرکب برای عملکرد دانه اختلاف معنی داری را در سطح احتمال یک درصد برای اثرات سال، ژنوتیپ، ژنوتیپ × سال، سال × مکان و سال × مکان × ژنوتیپ نشان داد. مولفه اول و دوم در تجزیه امی به ترتیب 52.78 و 26.00 درصد از مجموع مربعات اثر متقابل را به خود اختصاص دادند. با توجه به مقادیر عددی مولفه های اثر متقابل ژنوتیپی و رتبه ژنوتیپ ها، مشخص شد که ژنوتیپ های2، 4، 5، 8، 10، 13 و20 نسبت به سایر ژنوتیپ ها از پایداری عملکرد بیشتری برخوردار بوده اند. همچنین طبق شاخص ارزش پایداری امی(ASV) ، به-ترتیب ژنوتیپ های 15، 9، 12، 18، 5، 4،10، 16، 2، 6، 7 و 8 به عنوان ژنوتیپ های پایدار تعیین شدند. از میان ژنوتیپ های پایدار ژنوتیپ های 10 (Roho/4/Zanbaka/3/ER/Apm//Lignee131/5/Otis)،8 (Baladieldawaia/5/AwBlack/Aths//Arar/3/9Cr279-07/Roho/4/DD-14/Rhn-03) و 2 (Zarjau/80-5151//Skorohod/3/Robur/WA2196-68//DZ40-66) دارای عملکرد دانه بالاتری بودند. بنابراین می توان این ژنوتیپ ها را برای استفاده در برنامه های اصلاحی آتی جهت معرفی ارقام جدید پیشنهاد نمود.

    *فرمولها به درستی نمایش داده نمی شود.

    کلیدواژگان: اثر متقابل ژنوتیپ × محیط، ارزش پایداری امی، شرایط آبی، شرایط دیم
  • شهین مددی، مهدی رحیمی*، مسعود احمدی افزادی، سعید میرزایی صفحات 331-340

    اصلاح ارقام پر محصول و با کیفیت مطلوب هدف اصلی برنامه های به نژادی است. در این راستا شناسایی ساختار ژنتیکی والدین مورد تلاقی و برآورد ترکیب پذیری عمومی و خصوصی، میزان هتروزیس، نحوه عمل ژن ها و همچنین برهمکنش آن ها با یکدیگر و محیط اهمیت دارد. به این منظور پنج لاین S7 ذرت و نتاج آن ها در قالب طرح بلوک های کامل تصادفی با دو تکرار تحت شرایط نرمال (دوره آبیاری پنج روز) و تنش کم آبیاری (دوره آبیاری هشت روز) در شرایط محیطی کرمان در سال 1396 در قالب یک طرح نیمه دای آلل مورد ارزیابی قرار گرفته و ترکیب پذیری عمومی و خصوصی برخی صفات کمی با روش دوم گریفینگ برآورد شدند. نتایج تجزیه واریانس مرکب معنی داری اثر ترکیب پذیری عمومی و خصوصی با محیط را در سطح یک درصد نشان داد که نشان دهنده متفاوت بودن نحوه توارث صفات در دو محیط بود. نتایج حاصل از تجزیه دای آلل به روش دوم گریفینگ در شرایط نرمال نشان داد که صفات تعداد دانه در ردیف، تعداد ردیف دانه، تعداد دانه در بلال و طول بلال بیشتر تحت تاثیر اثر غیرافزایشی ژن ها قرار داشتند، در حالی که در شرایط کم آبیاری این صفات بیشتر تحت تاثیر اثر افزایشی ژن ها قرار داشتند. لاین KSC704-S7-7 برای صفت عملکرد دانه و اکثر صفات وابسته با آن در هر دو شرایط ترکیب پذیری عمومی مثبت و معنی داری نشان داد. علاوه بر آن، تلاقی های P2×P4 و P1×P3 به ترتیب تحت شرایط کم آبیاری و نرمال برای عملکرد دانه و بیشتر صفات مرتبط با آن ترکیب پذیری خصوصی مثبت و معنی داری نشان دادند. از این رو این تلاقی ها به عنوان بهترین دورگ ها برای بهبود و افزایش عملکرد دانه ذرت برای شرایط تنش کم آبیاری و نرمال تعیین شدند.

    کلیدواژگان: تلاقی دی آلل، ترکیب پذیری عمومی و خصوصی، عمل ژن
  • معروف خلیلی*، محمدعلی ابراهیمی صفحات 341-355

    به منظور برآورد تنوع ژنتیکی و گروه بندی لاین های هاپلویید مضاعف جو از لحاظ صفات مرتبط با تخصیص مواد فتوسنتزی، 72 لاین هاپلویید مضاعف به همراه والدین Steptoe و Morex در مزرعه تحقیقاتی دانشگاه مهاباد در قالب طرح لاتیس ساده با دو تکرار و در دو شرایط عادی و تنش کم آبی مورد بررسی قرار گرفتند. نتایج نشان داد بین ژنوتیپ های مورد مطالعه از نظر کلیه صفات مورد بررسی اختلاف معنی داری وجود دارد. در هر دو شرایط، تفکیک متجاوز مثبت و منفی معنی دار برای کلیه صفات (به غیر از عملکرد بیولوژیک در شرایط نرمال) مشاهده شد. در هر دو شرایط آبیاری نرمال و تنش کم آبی، بالاترین مقدار وراثت پذیری خصوصی برای صفات شاخص برداشت، عملکرد دانه برآورد شد. بر اساس نتایج تجزیه رگرسیون گام به گام برای صفات موثر بر عملکرد دانه در شرایط نرمال، دو صفت وزن هزار دانه و انتقال مجدد مواد فتوسنتزی (0.89= R2) و در شرایط تنش کم آبی، شاخص برداشت، سهم انتقال مجدد در عملکرد دانه و انتقال مجدد (0.82 = R2) به عنوان موثرترین صفات بر عملکرد دانه شناسایی شدند. در شرایط آبیاری نرمال دو صفت وزن هزار دانه و انتقال مجدد مواد فتوسنتزی اثر مثبت و مستقیم بر عملکرد دانه داشتند در حالیکه در شرایط تنش کم آبی شاخص برداشت و انتقال مجدد اثر مستقیم مثبت و نقش انتقال مجدد در عملکرد دانه اثر منفی و مستقیمی بر عملکرد دانه نشان دادند. بر اساس نتایج تجزیه خوشه ای ژنوتیپ ها در شرایط نرمال به دو گروه و در شرایط تنش کم آبی به سه گروه دسته بندی شدند.

    کلیدواژگان: تنوع ژنتیکی، جو، هاپلوئید مضاعف، وراثت پذیری
  • نگین محاویه اسعدی، احسان بیژن زاده*، علی بهپوری صفحات 357-369

    بهینه سازی اندازه مبدا و استفاده مناسب از آن در شرایط تنش آبی نقش مهمی در افزایش عملکرد دانه ایفا می کند. به منظور تاثیر سطوح مختلف برگ زدایی بر فعالیت رنگیزه های فتوسنتری و آنزیمهای آنتی اکسیدانی در جهت بهبود عملکرد ارقام جو در شرایط تنش، آزمایشی گلخانه ای به صورت فاکتوریل در قالب طرح کاملا تصادفی با سه تکرار اجرا شد. تیمارها شامل رژیم آبیاری در دو سطح آبیاری مطلوب (شاهد) و قطع آبیاری در ابتدای شیری شدن دانه، چهار رقم جو (زهک، نیمروز، ریحان و خاتم) و سه تیمار برگ زدایی شامل بدون حذف برگ، حذف همه برگ ها به غیراز برگ پرچم و حذف همه برگ ها به غیراز برگ پرچم و ماقبل پرچم بودند. نتایج نشان داد که تنش آبی بر محتوای کلروفیل a و b، کاروتنویید، آنزیم کاتالاز، پراکسیداز، عملکرد بیولوژیک، شاخص برداشت و عملکرد دانه اثر معنی داری داشت. در همه سطوح برگ زدایی در شرایط تنش آبی محتوای کلروفیل a در رقم ریحان بیشتر از سایر ارقام بود. همچنین تنش خشکی و برگ زدایی باعث کاهش 87.71 درصدی میزان کاروتنویید در رقم زهک شد. حذف همه برگ ها به غیراز برگ پرچم و ماقبل پرچم باعث افزایش فعالیت آنزیم کاتالاز به میزان 98.76 درصد در رقم ریحان در شرایط تنش آبی شد. از طرفی در شرایط تنش آبی حذف همه برگ ها به غیر از برگ پرچم منجر به افزایش فعالیت آنزیم پر اکسیداز در همه ارقام به غیر از رقم نیمروز شد. به نظر می رسد اعمال تیمار برگ زدایی با افزایش محتوای کلروفیل a و فعالیت آنزیم های آنتی اکسیدانی بویژه پراکسیداز باعث افزایش مقاومت گیاه به تنش آبی در برخی ارقام جو نظیر ریحان شده است به گونه ای که حذف همه برگها به غیر از برگ پرچم باعث افزایش معنی دار شاخص برداشت و عملکرد رقم ریحان نسبت به سایر ارقام در شرایط تنش خشکی شده است.

    کلیدواژگان: برگ پرچم، برگ زدایی، پراکسیداز، کاتالاز، کاروتنوئید
  • لعیا مرادبیگی*، احمد غلامی، امیرحسین شیرانی راد، حمید عباس دخت، حمید رضا اصغری صفحات 371-386

    به منظور بررسی اثر کاشت تاخیری و تنش خشکی آخر فصل بر صفات عملکرد و اجزای عملکرد، اسیدهای چرب اشباع و غیر اشباع، به منظور بررسی اثر تاریخ کاشت و تنش خشکی بر صفات عملکرد و اجزای عملکرد، اسیدهای چرب اشباع و غیر اشباع، میزان روغن و گلوکوزینولات دانه و محتوای پرولین کلزا آزمایشی به صورت فاکتوریل اسپلیت پلات در قالب طرح بلوک های کامل تصادفی با سه تکرار در دو سال زراعی 95-1393 در مزرعه تحقیقاتی موسسه تحقیقات اصلاح و تهیه نهال و بذر کرج اجرا گردید. تیمارهای مورد بررسی شامل تاریخ کاشت در دو سطح شامل: 20 مهر (کشت معمول) و 5 آبان (کشت تاخیری)، آبیاری در دو سطح شامل: آبیاری کامل (شاهد) و تنش خشکی (قطع آبیاری از مرحله خورجین دهی) و نیز ارقام و هیبریدهای پاییزه کلزا شامل:Neptune, Elvise, Okapi, Tassilo, GKH0224, GKH2624, GKH3705 بودند. نتایج آزمایش نشان داد، که تاریخ کاشت، آبیاری و رقم بر تمام صفات به غیر از اسید اکوزنوییک معنی دار بود. به تاخیر انداختن تاریخ کاشت، تعداد خورجین در بوته، وزن هزاردانه، عملکرد دانه، میزان روغن دانه، اکوزنوییک اسید و پرولین را کاهش ولی میزان گلوکوزینولات دانه و اسید بهنیک را افزایش داد. بیش ترین میزان روغن دانه (6/45 درصد) در حالت آبیاری کامل و کشت معمول و کم ترین آن (42.2درصد) در شرایط قطع آبیاری در مرحله خورجین دهی و کشت تاخیری به دست آمد. بالاترین میزان پرولین (21.59 میلی گرم بر گرم وزن تر) در کشت معمول و از رقم GKH3705 به دست آمد. از نظر عملکرد و اجزای عملکرد، محتوای روغن دانه، اسیدهای چرب اشباع و غیر اشباع و میزان گلوکوزینولات، رقم GKH3705 مناسب ترین بود. با توجه به نتایج، به نظر می رسد تاریخ کاشت 20 مهر و رقم GKH3705 در هر دو شرایط بدون تنش و تنش خشکی می تواند به عنوان بهترین تیمار برای سودمندی تولید کلزا در منطقه کرج پیشنهاد گردد.

    کلیدواژگان: اسید چرب، پرولین، تاریخ کاشت، قطع آبیاری، گلوکوزینولات
  • حمداله اسکندری*، اشرف عالی زاده امرایی، عبداله جوانمرد صفحات 387-399

    یک پژوهش مزرعه ای در سال زراعی 95-1394 در شهرستان سلسله اجرا گردید تا اثر آبیاری محدود ناشی از آبیاری جزیی ریشه بر عملکرد و کیفیت علوفه و بهره وری آب گندم و شبدر ایرانی در کشت خالص و مخلوط مورد بررسی قرار گیرد. آزمایش به صورت فاکتوریل دو عاملی بر پایه طرح بلوک های کامل تصادفی با سه تکرار انجام شد. عامل اول روش آبیاری (آبیاری کامل و آبیاری جزیی سیستم ریشه ای) و عامل دوم الگوی کاشت (کشت خالص گندم، کشت خالص شبدرایرانی، کشت مخلوط روی ردیف های جداگانه و کشت مخلوط روی یک ردیف) بود. نتایج نشان داد که عملکرد علوفه در تمامی الگوهای کاشت به طور منفی تحت تاثیر آبیاری جزیی ریشه قرار گرفت. با اعمال آبیاری جزیی ریشه، تولید ماده خشک در کشت خالص گندم، کشت خالص شبدر ایرانی، کشت مخلوط روی یک ردیف و کشت مخلوط روی ردیف های جداگانه به ترتیب 16، 15، 9 و 8 درصد کاهش پیدا کرد. آبیاری جزیی ریشه باعث بهبود بهروه وری آب برای تولید علوفه در کلیه الگوهای کاشت شد. کشت های مخلوط دارای بیشترین درصد افزایش بهره وری آب (برای کشت مخلوط روی یک ردیف و روی ردیف های جداگانه به ترتیب 83 و 77 درصد) بودند. آبیاری جزیی ریشه کیفیت علوفه در کشت مخلوط را کاهش داد به طوری که ADF و NDF به ترتیب 6 و 4 درصد افزایش و پروتیین خام و ماده خشک قابل هضم به ترتیب 15 و 7 درصد کاهش پیدا کردند. با این حال، کیفیت علوفه در کشت مخلوط بیشتر از کشت خالص گندم بود. نسبت برابری زمین تنها در شرایط آبیاری جزیی ریشه بیشتر از یک بدست آمد (1.024) که 8.8 درصد بیشتر از مقدار آن در شرایط آبیاری کامل ریشه بود. به عبارت دیگر برای تولید علوفه، کشت مخلوط گندم و شبدرایرانی تنها در شرایط آبیاری جزیی ریشه دارای مزیت است.

    کلیدواژگان: بهره وری آب، تنش خشکی، تولید علوفه، نسبت برابری زمین
  • احمد پورجمشید*، مهرداد قیصری، علی شریفی نیک، فیصل سالمی صفحات 401-412

    به ‏منظور بررسی اثر محلول ‏پاشی عناصر ریزمغذی بر برخی صفات فیزیولوژیک و زراعی گندم نان (.Triticum aestivum L) تحت شرایط آبیاری کامل و تنش خشکی انتهایی، آزمایشی به‏ صورت کرت‏ های خرد شده با چهار تکرار در شهرستان رامهرمز اجرا گردید. عوامل آزمایشی شامل تنش خشکی در دو سطح آبیاری کامل (عدم تنش خشکی) و قطع آبیاری از آغاز مرحله گل‏دهی تا رسیدگی فیزیولوژیک (تنش خشکی انتهایی) به‏ عنوان عامل اصلی و محلول‏ پاشی عناصر ریزمغذی در شش سطح عدم محلول‏ پاشی (شاهد)، محلول‏ پاشی با آب، آهن، روی، منگنز و آهن + روی + منگنز (هر کدام سه لیتر در هکتار) به‏ عنوان عامل فرعی بودند. نتایج نشان داد، تنش خشکی انتهایی به‏ جز محتوای پرولین برگ و پروتیین دانه، صفات شاخص کلروفیل برگ، شاخص پایداری غشای سلول، عملکرد دانه، عملکرد بیولوژیک و شاخص برداشت را به‏ طور معنی‏ داری کاهش داد. با این وجود، محلول‏ پاشی عناصر ریزمغذی آهن، روی و منگنز صفات اندازه‏ گیری شده در هر دو شرایط عدم تنش و تنش خشکی انتهایی را به ‏طور معنی ‏داری افزایش دادند. در این میان، کاربرد محلول ‏پاشی روی بیشترین اثر را در کاهش آسیب ناشی از تنش خشکی انتهایی بر صفات مورد اندازه‏ گیری نشان داد. به‏ طور کلی، استفاده از عناصر ریزمغذی به ‏ویژه روی به ‏صورت محلول‏ پاشی می‏تواند اثرات زیان‏بار ناشی از تنش خشکی انتهایی را کاهش و موجب بهبود صفات فیزیولوژیک، زراعی و محتوای پروتیین دانه گندم نان در منطقه رامهرمز شود.

    کلیدواژگان: آهن، تنش ‏های محیطی، روی، منگنز
  • علی نخ زری مقدم*، ناصر صمصامی، علی راحمی کاریزکی، اسماعیل قلی نژاد صفحات 413-423

    به منظور بررسی تاثیر تنش کم آبی و تلقیح با قارچ میکوریزا و باکتری ریزوبیوم بر صفات فیزیولوژیک و عملکرد دانه سویا، آزمایشی در سال زراعی 1396 در مزرعه هنرستان کشاورزی شهرستان ارومیه به صورت اسپلیت پلات فاکتوریل در قالب طرح بلوک های کامل تصادفی با سه تکرار اجرا شد. عامل تنش کم آبی در سه سطح شامل آبیاری مطلوب، تنش ملایم و تنش شدید کم آبی (به ترتیب آبیاری بعد از 70، 110 و 159 میلی متر تبخیر از تشتک تبخیر کلاس A)، عامل های فرعی قارچ میکوریزا در سه سطح شامل بدون میکوریزا، گونه Funneliformis mosseae و گونه Rhizophagus intraradices و باکتری ریزوبیوم در دو سطح شامل عدم تلقیح و Bradyrhizobium japonicum بود. در این بررسی دمای برگ، محتوای نسبی آب برگ، کلروفیل b، کلروفیل a، پرولین، نشت الکترولیت و عملکرد دانه مطالعه شد. تنش بیشتر کم آبی همراه با عدم تلقیح با میکوریزا دمای برگ را افزایش اما محتوی نسبی آب برگ و کلروفیل b را کاهش داد. افزایش تنش کم آبی همراه با عدم تلقیح با باکتری دمای برگ را افزایش اما کلروفیل b و عملکرد دانه را کاهش داد. تلقیح با باکتری با یا بدون تلقیح با قارچ دمای برگ را کاهش داد. این شرایط برای صفات محتوای نسبی آب برگ، محتوای کلروفیل b و a نیز وجود داشت. تلقیح با باکتری و میکوریزا بخصوص قارچ F. mosseae باعث شد حداکثر عملکرد دانه با 443.2 گرم در مترمربع به دست آید. میزان پرولین و درصد نشت الکترولیت در تیمار تنش کم آبی شدید و عدم تلقیح با میکوریزا و باکتری بیشتر از تیمارهای دیگر بود. حداقل میزان پرولین و درصد نشت الکترولیت نیز در تیمار آبیاری مطلوب همراه با تلقیح با باکتری و قارچ F. mosseae مشاهده شد. درمجموع، تنش کم آبی باعث ایجاد شرایط نامطلوب برای سویا شد که نتیجه آن کاهش عملکرد بود اما تلقیح با باکتری و قارچ باعث کاهش شرایط نامطلوب و رشد بهتر سویا شد.

    کلیدواژگان: پرولین، دمای برگ، کلروفیل، نشت الکترولیت
  • مهدی صاحب حسن، یحیی سلاح ورزی*، جعفر نباتی، مجید عزیزی صفحات 425-440

    به منظور بررسی اثر کاربرد باکتری های محرک رشد گیاه و قارچ مایکوریزا تحت شرایط تنش خشکی در زمستان و بهار سال های 1396-1397 آزمایشی به صورت فاکتوریل بر پایه طرح کاملا تصادفی با 4 تکرار در گلخانه تحقیقاتی گروه علوم باغبانی دانشکده کشاورزی دانشگاه فردوسی مشهد انجام شد. عامل اول استفاده از کود زیستی در 8 سطح (شامل ترکیب های مختلفی از باکتری های سودوموناس، ازتوباکتر و قارچ مایکوریزا) و عامل دوم تنش خشکی در دو سطح (100 و 50 % ظرفیت زراعی) بود. نتایج نشان داد که با کاهش ظرفیت زراعی خاک از 100 به 50 درصد ظرفیت زراعی ارتفاع گیاه، تعداد برگ، تعداد گل، قطر گل، وزن تر اندام هوایی و ریشه، تعداد شاخه جانبی، شاخص سبزینگی و محتوی نسبی آب برگ نسبت به تیمار شاهد کاهش یافت. همچنین بالاترین مقادیر ظرفیت آنتی اکسیدانی گیاهان مورد آزمایش، تحت هر دو شرایط رطوبتی خاک در تیمارهای Ps، M+Az و Ps+Az بدست آمد. از طرفی با کاربرد باکتری Pseudomonas fluorescens به تنهایی و یا در ترکیب با قارچ مایکوریزا در شرایط اعمال تنش (50% ظرفیت زراعی) صفات رشدی در گیاه مثل تعداد برگ، تعداد گل، قطر گل، تعداد ساقه جانبی و شاخص سبزینگی بهبود یافتند. تعداد گل در تیمار کاربرد باکتری Pseudomonas fluorescens در شرایط 100% ظرفیت زراعی خاک برابر 18.50 بود که نسبت به تیمار شاهد (عدم استفاده از کود های زیستی در 100% ظرفیت زراعی) 77% افزایش داشت. بیشترین شاخص سبزینگی در تیمار کاربرد توام مایکوریزا و باکتری Azotobactore chroococcum در شرایط رطوبتی 50% ظرفیت زراعی (33.92) حاصل شد. در نهایت می توان بیان کرد کاربرد قارچ Pseudomonas fluorescens در خاک به تنهایی یا توام با قارچ مایکوریزا در گیاه همیشه بهار در شرایط تنش خشکی قابلیت بهبود رشد گیاه را داشته و منجر به افزایش کارایی گیاه در شرایط تنش خشکی می شود.

    کلیدواژگان: تعداد گل، حداکثر کارایی فتوسیستم II، درصد فعالیت آنتی اکسیدانتی، محتوای رطوبت نسبی، نشت الکترولیت
  • ابوالفضل باغبانی آرانی، ظهراب اداوی* صفحات 441-453

    به منظور بررسی اثر تنش کم آبی و مصرف باکتری های محرک رشد بر صفات مورفولوژیک، فیزیولوژیک، عملکرد کمی و کیفی و ترکیبات روغن دانه دو رقم ارزن، آزمایشی به صورت اسپلیت فاکتوریل در قالب طرح پایه ی بلوک های کامل تصادفی با چهار تکرار در سال 1396 در مزرعه تحقیقاتی در شهرستان فریدونشهر اجرا گردید. در این آزمایش تنش کم آبی به عنوان عامل اصلی در سه سطح (تامین 100، 75 و 50 درصد نیاز آبی گیاه) در کرت های اصلی و کاربرد باکتری های محرک رشد در سه سطح شامل عدم بذرمال و بذرمال با 0.5 و یک لیتر باکتری های محرک رشد (باکتری ازتوباکتر کروکوکوم و آزوسپیریلوم برازیلنس) و دو گونه ارزن [ارزن دم روباهی (Setaria italica) رقم باستان و ارزن معمولی (Panicum miliaceum L.) اکوتیپ گلباف] به عنوان عوامل فرعی به صورت فاکتوریل در کرت های فرعی بودند. در این آزمایش تنش کم آبی موجب کاهش معنی دار صفات قطر ساقه، پایداری غشای سلولی، عملکرد بیولوژیک و دانه، درصد پروتیین و روغن و کیفیت آن در ارزن گردید. کاربرد باکتری های محرک رشد توانست اثرات نامطلوب ناشی از تنش کم آبی را بر صفات فوق الذکر در هر دو گونه ارزن کاهش دهد و سبب بهبود کیفیت روغن گردد به گونه ای که به ترتیب استفاده نیم و یک لیتر باکتری های محرک رشد، سبب افزایش عملکرد دانه به میزان (6.66 و 19.19%) در تیمارهای آبیاری شاهد، (12.29 و 28.76%) در تنش ملایم و (31.73 و 45.07%) در تیمار شدید کم آبی گردید. تنش ملایم کم آبی (75 درصد نیاز آبی) به همراه کاربرد یک لیتر باکتری های محرک رشد در رقم باستان، ضمن کاهش مصرف آب، بالاترین کیفیت (درصد اولییک و لینولییک) روغن را تولید نمود. همچنین رقم باستان از نظر عملکرد بیولوژیک، عملکرد دانه و اسیدهای چرب غیراشباع در سطوح مختلف آبیاری، با و بدون کاربرد باکتری های محرک رشد نسبت به رقم گلباف برتری نشان داد.

    کلیدواژگان: تنش آبی، اسیدهای چرب، ازتوباکتر، ازوسپیریلیوم، صفات کیفی
  • فاطمه محتشمی، محمودرضا تدین* صفحات 455-469

    به منظور بررسی اثر تیمار های کم آبیاری و محلول پاشی با اسید جاسمونیک و اسید آسکوربیک بر برخی از صفات رشدی و عملکردی ژنوتیپ های گلرنگ، آزمایشی به صورت اسپلیت- فاکتوریل در قالب طرح پایه بلوک های کامل تصادفی با سه تکرار در مزرعه پژوهشی دانشکده کشاورزی دانشگاه شهرکرد در بهار 1396 انجام شد. در این آزمایش تیمارهای کم آبیاری (100، 75 و 50 درصد نیاز آبی گلرنگ) به عنوان عامل اصلی و سه ژنوتیپ گلرنگ) محلی اصفهان، فرامان و سینا) و محلول پاشی با سه سطح شامل (کنترل، محلول پاشی با اسید جاسمونیک با غلظت 0.5 میلی مولار و محلول پاشی با اسید آسکوربیک با غلظت 20 میلی مولار) به عنوان عامل فرعی انتخاب شدند. تنش کم آبیاری موجب کاهش معنی دار ارتفاع بوته، تعداد غوزه در بوته، تعداد دانه در غوزه، وزن هزار دانه، عملکرد دانه، درصد روغن، اسید های چرب غیر اشباع اسید اولییک و اسید لینولییک شد. کمترین عملکرد دانه (1382.22 کیلوگرم در هکتار) و درصد روغن (26.67) از تیمار تنش کم آبیاری 50 درصد نیاز آبیاری و بیشترین عملکرد دانه (1635.2 کیلوگرم در هکتار) و درصد روغن (27.21) از تیمار 100 درصد نیاز آبیاری به دست آمد. در بین ژنوتیپ های گلرنگ بیشترین عملکرد دانه (1676.3 کیلوگرم در هکتار) و درصد روغن (27.82) در ژنوتیپ سینا و کمترین عملکرد دانه (1341.2 کیلوگرم در هکتار) و درصد روغن (27.66) در ژنوتیپ محلی اصفهان مشاهده شد. محلول پاشی با اسید جاسمونیک و اسید آسکوربیک موجب افزایش عملکرد دانه، درصد روغن، محتوای اسید لینولییک و اسید اولییک و موجب کاهش اسید پالمتبک و اسید استیاریک شد. نتایج نشان داد که تفاوت‏ در میزان برخی از صفات در بین ژنوتیپ ‏های آزمایشی و تیمار های محلول پاشی، مانند افزایش محتوای اسید های چرب غیر اشباع می‏ تواند در انتخاب ژنوتیپ ‏برتر و تعیین مناسب ترین تیمار جهت تعدیل اثر نامطلوب تنش کم آبیاری به منظور دست یابی به افزایش تولید اقتصادی مورد استفاده قرار گیرد.

    کلیدواژگان: ارتفاع بوته، اسید اولئیک، اسید لینولئیک، درصد روغن
  • علی زارعی، جعفر مسعود سینکی*، مجید امینی دهقی، علی دماوندی صفحات 471-489

    به منظور بررسی اثر قطع آبیاری و محلول پاشی با کیتوزان و نانوکود فسفر بر عملکرد و اجزای عملکرد و کیفیت دانه ارقام کنجد بعد از کشت گندم، آزمایشی به صورت اسپلیت پلات فاکتوریل در سه تکرار در مزرعه پژوهشی دانشگاه شاهد تهران در سال های زراعی 95- 1394 و 96-1395 انجام شد. عوامل آزمایش شامل قطع آبیاری در سه سطح براساس مراحل فنولوژیکی، عدم تنش (آبیاری نرمال)، قطع آبیاری در 50 درصد دانه بندی و گلدهی در کرت های اصلی و محلول پاشی در چهار سطح شامل عدم محلول پاشی، نانو کلات فسفر (دو در هزار)، کیتوزان (سه در هزار) و ترکیب نانو کلات فسفر+کیتوزان و دو رقم اولتان و ناز تک شاخه کنجد در کرت های فرعی بودند. نتایج نشان داد بیشترین وزن هزار دانه در سال اول آزمایش و رقم اولتان (3.10 گرم) به دست آمد. بیشترین عملکرد دانه در سال دوم، تحت شرایط بدون تنش و تنش متوسط و محلول پاشی با نانو کلات فسفر به تنهایی یا در ترکیب کیتوزان (به ترتیب 2821.8، 2572.4، 2808.4 و 2904.5 کیلوگرم در هکتار) مشاهده شد. به طور کلی در بین سطوح مختلف تنش خشکی، تنش شدید (آبیاری تا 50 درصد گلدهی) منجر به کاهش معنادار میانگین عملکرد دانه (بیش از 50 درصد) گردید، ولی تنش خشکی متوسط (آبیاری تا 50 درصد دانه بندی) به خصوص در شرایط استفاده از ترکیبات کیتوزان و نانو کود فسفر دارای بالاترین عملکرد دانه (5/2904 کیلوگرم در هکتار) بود. درصد روغن دانه در سال دوم تحت شرایط عدم تنش دارای بالاترین میانگین (57.02 درصد) بود. در مقایسه بین دو رقم، بیشترین و کمترین عملکرد روغن به ترتیب در رقم ناز و اولتان (858.4 و 731.7 کیلوگرم در هکتار) مشاهده شد. میزان اسیدهای چرب اشباع (پالمیتیک و استیاریک) در تیمار عدم محلولپاشی در رقم اولتان دارای بالاترین میانگین (به ترتیب 12.5 و 9.3) و برعکس، کمترین محتوای اسید چرب لینولییک (24.88 درصد) در این تیمار مشاهده شد. به طورکلی استفاده از نانو کود فسفر به همراه کیتوزان باعث افزایش کمی و کیفی عملکرد دانه کنجد گردید و منجر به افزایش شاخص های رشدی و کیفی در شرایط تنش خشکی شد.

    کلیدواژگان: اسیدهای چرب، تنش خشکی، عملکرد دانه، کشت دوم، محلول پاشی
  • ابراهیم خلیل وند بهروزیار* صفحات 491-502

    به منظور بررسی اثر تنش کمبود آب و محلول پاشی با نانو ذرات دی اکسید تیتانیوم بر وزن بلال و برخی ویژگیهای بیوشیمیایی ذرت شیرین، آزمایشی به صورت کرتهای خرد شده در قالب طرح بلوکهای کامل تصادفی در سه تکرار در ایستگاه تحقیقاتی دانشکده ی کشاورزی دانشگاه آزاد اسلامی واحد تبریز در سال 1396 به اجرا در آمد. تیمارهای آزمایشی عبارت از تنش کمبود آب در سه سطح 50، 75 و 100 درصد رطوبت قابل دسترس و محلول پاشی با نانو ذرات دی اکسید تیتانیوم در چهار سطح صفر، 0.01، 0.03 و 0.05 درصد بودند. ننتایج نشان داد که محلول پاشی نانو دی اکسید تیتانیوم بر فعالیت آنزیم پراکسیداز و اثر متقابل محلول پاشی نانو دی اکسید تیتانیوم و تنش کمبود آب بر میزان آنزیم مالون دی آلدیید، قندهای محلول، پرولین و وزن بلال معنی دار بود. محلول پاشی نانو دی اکسید تیتانیوم با غلظت 0.01 درصد موجب افزایش فعالیت آنزیم پراکسیداز شد اما با افزایش غلظت، فعالیت این آنزیم کاهش یافت. همچنین محلول پاشی با نانو دی اکسید تیتانیوم با غلظت 0.01 درصد در تیمار 50 درصد رطوبت قابل دسترس موجب افزایش میزان قندهای محلول، پرولین و کاهش مالون دی آلدیید گردید و در تیمار آبیاری کامل در مقایسه با عدم محلول پاشی در تیمار 50 درصد رطوبت قابل دسترس و شاهد (عدم محلول پاشی در تیمار 100 درصد رطوبت قابل دسترس) وزن بلال را به ترتیب 38.5 و 9.7 درصد افزایش داد. در کل محلول پاشی با غلظت 0/01 درصد نانو دی اکسید تیتانیوم در شرایط تنش کمبود آب توانست با تاثیرگذاری بر فعالیت آنزیم های مرتبط با کاهش اثرات مخرب تنش، منجر به افزایش وزن بلال در شرایط مشابه و عدم مصرف این ترکیب گردد.

    کلیدواژگان: پراکسیداز، پرولین، قندهای محلول، مالون دی آلدئید
  • اعظم رومانی*، عباس بیابانی، علی راحمی کاریزکی، ابراهیم غلامعلی پور علمداری، عبداللطیف قلی زاده صفحات 503-517

    به منظور بررسی اثر تنش خشکی بر خصوصیات کمی و کیفی گیاه دارویی اسفرزه مطالعه ای به صورت اسپلیت فاکتوریل در قالب طرح بلوک های کامل تصادفی با 18 تیمار و سه تکرار در زمستان 1394 در مزرعه پژوهشی دانشگاه گنبدکاووس اجرا شد. در این آزمایش تیمارهای آبیاری (شاهد (بدون تنش)، قطع آبیاری در مرحله گل دهی و قطع آبیاری در مرحله پر شدن دانه) به عنوان فاکتور اصلی و اسید سالیسیلیک (صفر، 0.4 و 0.8 میلی مولار) و اسپرمین (صفر و 0.02 میلی مولار) به عنوان فاکتور فرعی در نظر گرفته شدند. صفات مورد بررسی شامل؛ طول سنبله، تعداد دانه در بوته، وزن هزار دانه، عملکرد بیولوژیک، عملکرد دانه، شاخص برداشت، درصد موسیلاژ، عملکرد موسیلاژ، فاکتور تورم بذر، میزان تورم در هر گرم موسیلاژ و درصد پوسته بودند. نتایج تجزیه واریانس داده ها نشان داد که در اکثر صفات به جز تعداد پنجه در بوته، تعداد دانه در بوته و فاکتور تورم بذر بین اثرات تلفیقی قطع آبیاری، اسید سالیسیلیک و اسپرمین در سطح احتمال یک و پنج درصد اختلاف معنی داری وجود داشت. براساس نتایج حاصل بیش ترین میزان عملکرد دانه (8/540 کیلوگرم در هکتار) و عملکرد بیولوژیک (2795 کیلوگرم در هکتار) از تیمار محلول پاشی اسید سالیسیلیک با غلظت 0.8 میلی مولار در شرایط قطع آبیاری در مرحله پر شدن دانه به دست آمد. بیش ترین درصد موسیلاژ دانه معادل 19.7 و میزان تورم برای هر گرم موسیلاژ (105.7 میلی لیتر) به تیمار محلول پاشی برگی اسید سالیسیلیک با غلظت 0.4 میلی مولار و اسپرمین با غلظت 0.02 میلی مولار به ترتیب تحت شرایط آبیاری کامل و قطع آبیاری در مرحله پر شدن دانه اختصاص داشت. با توجه به یافته های آزمایش استنباط می شود که محلول پاشی برگی گیاه دارویی اسفرزه با اسید سالیسیلیک و اسپرمین به غلظت های مناسب بتواند گامی موثر در جهت کاهش اثرات سوء ناشی از تنش کم آبی باشد.

    کلیدواژگان: اسفرزه، ترکیبات پلی آمینی، تنش کم آبی، تورم بذر، موسیلاژ
  • حدیث حسنوند*، سید عطاءاله سیادت، عبدالمهدی بخشنده، محمدرضا مرادی تلاوت، عادل پشتدار صفحات 519-531

    به منظور بررسی تاثیر سالیسیلیک اسید بر عملکرد و جذب عناصر غذایی گل گاوزبان اروپایی در شرایط قطع آبیاری آزمایشی به صورت کرت های خردشده در قالب بلوک های کامل تصادفی با چهار تکرار در سال زراعی 97-96 در مزرعه تحقیقاتی دانشگاه علوم کشاورزی و منابع طبیعی خوزستان انجام شد. عوامل آزمایشی شامل قطع آبیاری در مرحله ساقه دهی، گلدهی، پرشدن دانه و آبیاری کامل در کرت های اصلی و محلول پاشی سالیسیلیک اسید در غلظت (صفر، 69، 138 و 207 میلی گرم در لیتر) در کرت های فرعی مورد بررسی قرار گرفتند. نتایج نشان داد که قطع آبیاری و سالیسیلیک اسید تاثیر معنی داری بر عملکرد دانه، درصد روغن، درصد خاکستر و جذب عناصر غذایی نیتروژن، فسفر، پتاسیم و سدیم در دو بخش گل و برگ داشت. مقایسه میانگین تیمارها نشان داد که در اثر قطع آبیاری در مراحل ساقه دهی و گلدهی، فقط میزان غلظت عناصر سدیم و پتاسیم و درصد روغن به طور معنی داری افزایش یافت. حداکثر عملکرد دانه در تیمار آبیاری کامل به میزان 633.43 کیلوگرم در هکتار به دست آمد. محلول پاشی با غلظت 207 میلی گرم در لیتر سالیسیلیک اسید سبب افزایش 50 درصدی عملکرد دانه نسبت به تیمار عدم محلول پاشی شد. سالیسیلیک اسید تمام صفات مورد بررسی به جزء مقدار سدیم را افزایش داد. اثر متقابل فاکتورها نیز بر خاکستر گل، پتاسیم گل و برگ، فسفر برگ و سدیم گل معنادار بود. مصرف 138 میلی گرم در لیتر سالیسیلیک اسید در شرایط بدون قطع آبیاری، سبب افزایش 38 درصدی فسفر برگ نسبت به شرایط عدم مصرف سالیسیلیک اسید و تنش خشکی شد. بیشترین میزان پتاسیم گل و برگ با محلول پاشی 138 و 207 میلی گرم در لیتر سالیسیلیک در تنش قطع آبیاری در مرحله گلدهی به دست آمد. نتایج این آزمایش نشان داد که کاربرد سالیسیلیک اسید در غلظت های 138 و 207 میلی گرم در لیتر در گل گاوزبان اروپایی می تواند باعث کاهش قابل ملاحظه آسیب های ناشی از تاثیرات منفی قطع آبیاری گردد.

    کلیدواژگان: پتاسیم، درصد خاکستر، سدیم، کم آبی، گل گاوزبان اروپایی، نیتروژن
  • ساره خواجه حسینی، فرزاد فنودی*، سید علی طباطبایی، رستم یزدانی بیوکی، جعفر مسعود سینکی صفحات 533-546

    به منظور ارزیابی کاربرد و زمان مصرف اسید آمینه گلایسین روی رشد، عملکرد و فعالیت آنتی اکسیدانی گیاه دارویی زوفا (Hyssopus officinalis L.) تحت شرایط مختلف آبیاری، آزمایشی به صورت اسپلیت پلات فاکتوریل در قالب طرح بلوک های کامل تصادفی در سه تکرار در سال زراعی 96- 1395 در مزرعه ی تحقیقاتی مرکز تحقیقات کشاورزی و منابع طبیعی استان یزد انجام شد. تیمارهای آزمایشی شامل رژیم های آبیاری در سه سطح آبیاری 25، 50 و 75 درصد تخلیه آب قابل دسترس گیاه از خاک، به ترتیب شاهد، تنش متوسط، تنش شدید به عنوان تیمار اصلی و تیمارهای الف: محلول پاشی در دو سطح آب مقطر (شاهد) و اسیدآمینه گلایسین (2.5 در هزار) و ب: زمان محلول پاشی (رویشی و گلدهی، گلدهی) به عنوان کرت های فرعی در نظر گرفته شد. نتایج نشان داد تیمارهای مختلف آبیاری باعث کاهش صفت های تعداد شاخه جانبی، تعداد برگ، عملکرد وزن تر، عملکرد وزن خشک و فنل کل گردید اما میزان آنتوسیانین افزایش پیدا کرد. بین تیمارهای زمان محلول پاشی در صفات مورد ارزیابی، اختلاف معنی داری مشاهده نگردید. بررسی اثرات متقابل نشان داد که ترکیب تیمارهای آبیاری شاهد و محلول-پاشی با گلایسین، باعث افزایش ارتفاع و تعداد شاخه جانبی شد. همچنین این ماده در ترکیب با تیمارهای آبیاری سطوح تنش متوسط و تنش شدید باعث افزایش تعداد برگ، عملکرد وزن تر و خشک گیاه، نسبت به شاهد شد. نتایج بررسی حاضر گویای آن بود که کاربرد خارجی اسیدآمینه گلایسین علاوه بر کاهش خسارات ناشی از کمبود آب را در گیاه، منجر به افزایش توانایی گیاه برای بهبود رشد و بالابردن عملکرد نیز شده است.

    کلیدواژگان: تعدیل اسمزی، رادیکال های آزاد، محلول پاشی، محلول های سازگار
  • بابک میرشکارنژاد، فرزاد پاکنژاد*، ابراهیم امیری، محمدرضا اردکانی، محمدنبی ایلکایی صفحات 547-557

    به منظور تعیین تاریخ کاشت مناسب تر و مدیریت آب آبیاری در دوره رشد ذرت دانه ای (S.C.704) آزمایشی در قالب کرت های خرد شده بر پایه طرح بلوک های کامل تصادفی با سه تکرار در دو سال زراعی 95-1394 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه تهران انجام شد. عوامل آزمایشی شامل سه تاریخ کاشت: یکم اردیبهشت، بیست و یکم اردیبهشت و دهم خرداد در کرت های اصلی و چهار سطح آبیاری (I40:40%ETc, I60:60%ETc, I80:80%ETc and I100:100%ETc) براساس نیاز آبی گیاه در کرت های فرعی اجرا شد. نتایج نشان دهنده کاهش عملکرد دانه به میزان 44 و 49 درصد به ترتیب در سال اول و دوم آزمایش در تیمار تنش کم آبیاری بر اساس 40 درصد نیاز آبی در مقایسه با تیمار شاهد آبیاری بر اساس 100 درصد نیاز آبی گیاه بود. عملکرد دانه در سال دوم به طور معنی داری (0.01 ≤p) به اثر متقابل بین تاریخ کاشت و آبیاری واکنش نشان داد به نحوی که سطوح بالای تبخیر و تعرق و تنش حرارتی شدید با اثر منفی بر مرحله گرده افشانی ذرت از عوامل اصلی تاثیرگذار در کاهش عملکرد دانه در تاریخ کاشت بیست و یکم اردیبهشت و دهم خرداد بودند. بالاترین مقادیر راندمان مصرف آب عملکرد دانه و زیست توده در تیمار کم آبیاری (I40) مشاهده شدند. ذرت های کاشته شده در تاریخ کاشت یکم اردیبهشت با افزایش طول دوره رشد و شرایط دمایی مناسب برای پرشدن دانه از توانایی بیشتری در تولید دانه های با وزن بالا برخوردار بودند. با توجه به شرایط اقلیمی منطقه، اتلاف آب از طریق تبخیر سطحی در ابتدای فصل رشد به مراتب کمتر می باشد. بنابراین انتخاب تاریخ کاشت زودهنگام ذرت دانه ای و پرهیز از آبیاری های مازاد بر نیاز گیاه برای دست یابی به حداکثر عملکرد بهینه و بهبود راندمان مصرف آب حایز اهمیت می باشند.

    کلیدواژگان: تبخیر و تعرق، تنش کم آبیاری، زیست توده، مرحله گرده افشانی ذرت
  • سید علی طباطبایی، سپیده نیکومرام، امید انصاری* صفحات 559-570

    دو عامل اولیه مهم کنترل کننده جوانه زنی دما و پتانسیل آب می باشند. با استفاده از مدل هیدروتایم می توان پاسخ جوانه زنی بذر به پتانسیل آب در دماهای مختلف را کمی سازی کرد. در این پژوهش با استفاده از مدل هیدروتایم پاسخ جوانه زنی بذر کلزا (.Brassica napus L) رقم اکاپی به سطوح مختلف پتانسیل آب در دماهای مختلف موردبررسی قرار گرفت. تیمارهای آزمایشی شامل سطوح مختلف خشکی (پتانسیل های 0، 0.2-، 0.4-، 0.6- و 0.8- مگا پاسکال) در دماهای 10، 15، 20، 25 و 30 درجه سانتی گراد بود. پاسخ جوانه زنی بذرها به سطوح مختلف پتانسیل آب در دماهای مختلف با استفاده از مدل هیدروتایم کمی سازی شد (جهت محاسبه ضرایب هیدروتایم برای هر دما از مدل هیدروتایم با توزیع نرمال استفاده شد). نتایج نشان داد که در تمامی سطوح پتانسیل آب با افزایش دما تا 25 درجه سانتی گراد، درصد جوانه زنی افزایش یافت و با افزایش پتانسیل آب، درصد جوانه زنی کاهش یافت. ضریب هیدروتایم (θH) با افزایش درجه حرارت به طور معنی داری کاهش یافت به طوری که کمترین ضریب هیدروتایم (11.24 مگاپاسکال ساعت) مربوط به دمای 30 درجه سانتی گراد بود. پتانسیل پایه با افزایش درجه حرارت به طور معنی داری کاهش یافت و بیشترین پتانسیل پایه منفی با میانگین 0.91- مگا پاسکال مربوط به دمای 20 درجه سانتی گراد و کمترین میزان پتانسیل پایه (Ψb(50)) با میانگین 0.52- مگاپاسکال مربوط به دمای 30 درجه سانتی گراد بود. کمترین ضریب انحراف توزیع پتانسیل پایه در جمعیت (σ Ψb(50)) (0.35) مربوط به دمای 30 درجه سانتی گراد بود. جهت کمی سازی پاسخ جوانه زنی بذر کلزا به سطوح مختلف پتانسیل آب در دماهای مختلف استفاده از مدل هیدروتایم دارای نتایج نسبتا قابل قبولی بود؛ بنابراین می توان با استفاده از خروجی مدل هیدروتایم در دماهای مختلف درصد جوانه زنی بذر کلزا را در پتانسیل های مختلف پیش بینی نمود.

    کلیدواژگان: توزیع نرمال، درصد جوانه زنی، دما، سرعت جوانه زنی
  • سید حمیدرضا هاشمی*، قربانعلی نعمت زاده، سمیرا محمدی، مارکوس کولمن صفحات 571-581

    فاکتورهای شوک حرارتی (Heat Shock Factors)، نقش مهمی در پاسخ به تنش های زیستی و غیرزیستی در یوکاریوت ها ایفا می نمایند. هدف از اجرای این تحقیق، شناسایی ژن های فاکتور رونویسی AlHSF در گیاه هالوفیت آلوروپوس لیتورالیس (Aeluropus littoralis) می باشد. بدین منظور شناسایی و تعیین مشخصه سازی ژن ها، ساختار ژنی، آنالیز موتیف های پروتیینی و روابط فیلوژنتیکی خانواده ژنی AlHSF مدنظر قرار گرفت. آنالیز الگوی بیان این ژن ها در دو بافت برگ و ریشه، تحت شرایط تنش شوری و شرایط ریکاوری، با استفاده از داده های RNA-seq صورت پذیرفت. بر اساس توالی های ژنومی A. littoralis، 11 ژن AlHSF غیرتکراری و منحصربفرد شناخته شدند. تمام 11 فاکتور رونویسی AlHSFs، بر اساس همولوژی با آرابیدوپسیس، به سه دسته (A، B و C) تقسیم شدند. بر اساس داده های RNA-seq، الگوی بیان ژن های AlHSF در بافت های برگ و ریشه تحت شرایط تنش شوری و ریکاوری، متفاوت بود. سطح بیان متفاوت این ژن ها، می تواند به عملکردهای مولکولی و مکانیسم های تنظیمی متفاوت در کنترل فعالیت این ژن ها مرتبط باشد. یافته های این تحقیق، ضمن ارایه خصوصیات عملکردی ژن های AlHSF، پایه ای برای تحقیقات کاربردی آینده در مورد نقش بیولوژیکی آن ها در تحمل گیاه آلوروپوس لیتورالیس به تنش های زیستی و غیرزیستی، فراهم می نماید.

    کلیدواژگان: آنالیز ترانسکریپتومیکس، آنالیز موتیف های پروتئینی، پروتئین های شوک حرارتی، ساختار ژنی
  • فریبا مرسلی، رضا درویش زاده*، غلامحسین غلامی صفحات 583-600

    به منظور بررسی تغییرات ریخت شناسی 98 رگه خویش آمیخته نوترکیب آفتابگردان دانه روغنی حاصل از تلاقی PAC2 × RHA266، در شرایط نرمال و تنش شوری 6 دسی زیمنس برمترمربع آزمایشی بصورت فاکتوریل در قالب طرح کاملا تصادفی با 3 تکرار در مزرعه تحقیقاتی دانشگاه ارومیه انجام شد. در هریک از شرایط بعد از مرحله گلدهی صفات عملکرد دانه، وزن 100 دانه، تعداد برگ، طول برگ، عرض برگ، طول دمبرگ، قطر ساقه، وزن خشک طبق و روز تا گلدهی اندازه گیری شدند. بر اساس نتایج تجزیه واریانس اثر متقابل شوری × رگه برای تمامی صفات به غیر از ارتفاع بوته معنی دار بود مقایسه میانگین رگه ها در هر دو شرایط نشان داد که میانگین رگه ها در شرایط تنش شوری نسبت به شرایط نرمال، در همه صفات بجز طول دمبرگ کاهش یافته است. بیشترین مقدار درصد کاهش در عملکرد دانه (13.23) و وزن صد دانه (10.60) مشاهده شد. نتایج رگرسیون گام به گام نشان داد که صفات قطر طبق و وزن 100 دانه در هر دو شرایط نرمال و تنش شوری وارد مدل شدند. بنابراین انتخاب برای این صفات در هر دو شرایط به بهبود عملکرد دانه کمک خواهد کرد. بر اساس نتایج قسمت اول پژوهش، دو رگه متحمل و حساس به شوری (به ترتیب رگه های C86 و C64) انتخاب و الگوی الکتروفورزی پروتیین ها در سطوح مختلف تنش شوری صفر، 2، 4، 6 و 8 دسی زیمنس برمترمربع بررسی گردید. بر اساس نتایج حاصله، الگوی الکتروفورزی متفاوتی برای رگه های C86 و C64 در سطوح مختلف تنش شوری مشاهده شد که حاکی از واکنش متفاوت رگه ها به تنش شوری می باشد. احتمالا باندهای پروتیینی با وزن مولکولی 55 و 83.45 کیلودالتون، پروتیین های مرتبط با تحمل به تنش شوری هستند که در رگه متحمل تغییرات بیان نشان می دهند. نتایج حاصل از این پژوهش می تواند در برنامه های به نژادی آفتابگردان جهت تولید ارقام متحمل به شوری مفید باشد.

    کلیدواژگان: آفتابگردان روغنی، الکتروفورز پروتئین ها، تنش شوری، رگرسیون گام به گام، وراثت پذیری
  • سمیه سنچولی، محمود قربانزاده نقاب، حسین صبوری*، محمد زارع مهرجردی صفحات 601-611

    شوری یک محدودیت عمده در توسعه کشت برنج می باشد. بهبود بخشیدن به تحمل به شوری در برنج ازنظر ژنتیکی یک مسیله بسیار مهم در برنامه های اصلاحی است. به منظور مکان یابی ژن های کنترل کننده محتوای کلروفیل، 96 لاین خالص نوترکیب برنج ایرانی حاصل تلاقی ارقام ندا × اهلمی-طارم تحت تنش شوری در مرحله گیاهچه ای آزمایشی به صورت مرکب در قالب طرح کاملا تصادفی با سه تکرار و دو شرایط کشت نرمال و تنش شوری در دانشگاه گنبد کاووس در سال 1395 در شرایط گیاهچه کشت شدند. مکان یابی ژن های کنترل کننده محتوای کلروفیل با استفاده از روش های مختلف مکان یابی شامل SIM-MEL، SIM، CIM، MIM، PMLE، ICIM و STSIM انجام گرفت و با استفاده از هر کدام از این روش ها QTLهای مشابه و متفاوتی ردیابی شد. 40 نشانگر SSR و 16 نشانگر ISSR (76 آلل تکثیر شده چند شکل)، 2 نشانگر IRAP (7 آلل تکثیر شده چند شکل) و یک نشانگر iPBS (3 آلل تکثیر شده چند شکل) بر روی 12 کروموزوم برنج توزیع شدند. روش ICIM، CIM و SIM در شرایط نرمال و تنش شوری بیشترین تشابه مکان های ژنی ردیابی شده را دارا بودند. qCHL-6 در شش روش مکان یابی در موقعیت 52 سانتی مورگان از کروموزوم 6 شناسایی شد. بنابراین با استفاده از QTLهای شناسایی شده می توان پس از تعیین اعتبار QTLها، ژنوتیپ های برتر از نظر محتوای کلروفیل برای برنامه های انتخاب به کمک نشانگر را شناسایی کرد.

    کلیدواژگان: صفات کمی، برنج، کشت هیدروپونیک، QTL
  • عاطفه رحمانی کمرودی، سعید نواب پور*، احد یامچی، علی اصغر نصرالله نژاد قمی صفحات 613-623

    هدف از این آزمایش بررسی تنوع ژنتیکی لاین های موتانت گندم (T-65-7-1 و T-67-60) و والد (طبسی) با استفاده از نشانگر مولکولی RAPD و همچنین مقایسه برخی شاخص های مورفولوژیکی و فیزیولوژیکی بین لاین های موتانت و والد در پاسخ به تنش شوری در مرحله گیاهچه ای بود. در این تحقیق دو لاین موتانت گندم (T-67-60 و T-65-7-1) به همراه رقم والد آن ها (رقم طبسی)، در محیط هیدروپونیک یوشیدا در شرایط روشنایی (16 ساعت روشنایی) و دمای30 درجه سانتی گراد به صورت فاکتوریل در قالب طرح کاملا تصادفی با سه تکرار کشت شدند. پس از اعمال تنش شوری در شرایط هدایت الکتریکی 6=EC دسی زیمنس برمتر، وزن تر و وزن خشک گیاهچه ها به عنوان صفات مورفولوژیک اندازه گیری شدند. همچنین نمونه های برگی جهت استخراج DNA و ارزیابی پارامترهای بیوشیمیایی (میزان پرولین، پروتیین و کلروفیل) برداشت گردیدند. تنوع ناشی از جهش القایی حاصل از پرتو گاما در گندم به کمک آغازگر مولکولی RAPD آشکار و تایید شد. الگوی حاصل از نشانگر RAPD نشان دهنده تشابه بیشتر لاین موتانت T-67-60 با رقم والد طبسی بود. مقایسه میانگین ها داده های مورفولوژیکی و فیزیولوژیکی حاکی از آن بود که لاین های موتانت نسبت به والد از تحمل نسبی بالاتری در شرایط تنش شوری برخوردار بودند. در مجموع، برتری معنی دار صفات مورفولوژیکی و فیزیولوژیکی مرتبط با تحمل به شوری در لاین های موتانت (T-67-60 و T-65-7-1) در مقایسه با رقم والد (طبسی) علاوه بر اهمیت کاربردی، مبین اثر گذاری جهش و موفقیت روند انتخاب طی نسل های تفکیک بود.

    کلیدواژگان: تنش شوری، فیزیولوژی، گندم موتانت، مورفولوژی، نشانگر RAPD
  • احمد آئین*، امیر جلالی صفحات 625-635

    گرمای شدید آخر فصل رشد، همواره یکی از چالش های مهم نظام کشت زمستانه سیب زمینی در مناطق گرم کشور ازجمله جنوب استان کرمان است. تنش گرمایی از طریق افزایش میزان تنفس و تغییر در میزان انباشت قندها و نشاسته در غده سیب زمینی، باعث کاهش عملکرد، کیفیت و مدت انبارمانی غده ها می شود. یکی از استراتژی های مناسب برای کاهش اثرات تنش گرمایی در سیب زمینی، استفاده از کلسیم به ویژه نیترات کلسیم می باشد که در این آزمایش موردبررسی قرارگرفته است. این آزمایش به صورت اسپلیت اسپلیت پلات در قالب بلوک های کامل تصادفی در سه تکرار در سال 93-92 در مرکز تحقیقات و آموزش کشاورزی جنوب کرمان (جیرفت) اجرا شد. فاکتور اصلی تاریخ کاشت در دو سطح (تاریخ کاشت به موقع و تاریخ کاشت دیرهنگام)، فاکتور فرعی ارقام در سه سطح (سانته، ساتینا و میلوا) و فاکتور فرعی فرعی کاربرد کلسیم در چهار سطح شامل: عدم کاربرد کلسیم، محلول پاشی نیترات کلسیم به میزان ppm 2500 در دو مرحله و سه مرحله و مصرف خاکی نیترات کلسیم به میزان 75 کیلوگرم در هکتار در دو مرحله بودند. نتایج بررسی نشان داد که برهمکنش کاربرد کلسیم و تنش گرمایی آخر فصل سبب کاهش میزان قند کل، قندهای احیاکننده و افزایش میزان نشاسته، کلسیم غده و کلسیم برگ نسبت به شاهد (عدم کاربرد نیترات کلسیم در شرایط تنش) شد. مصرف خاکی نیترات کلسیم در شرایط تنش گرمایی، میزان فساد و افت وزن غده ها را پس از یک دوره 60 روزه انبارمانی نسبت به شاهد (عدم کاربرد کلسیم در شرایط مشابه) 30.5 درصد کاهش داد که احتمالا به دلیل تاثیر کلسیم بر کاهش میزان قند غده و همچنین نقش آن در استحکام دیواره سلولی بافت غده می باشد.

    کلیدواژگان: تنش گرمایی، قندهای احیاکننده، محلول پاشی، مصرف خاکی، نیترات کلسیم
  • علیرضا برجیان بروجنی*، سید عطاالله سیادت، عبدالمهدی بخشنده، خلیل عالمی سعید، محمدرضا جلال کمالی صفحات 637-651

    به منظور بررسی دوره های کوتاه مدت تنش گرما بر عملکرد دانه و خصوصیات فیزیولوژیک گیاه گندم، آزمایشی در سال زراعی 94-1393 در مزرعه تحقیقاتی دانشگاه علوم کشاورزی و منابع طبیعی خوزستان به صورت بلوک های نواری در سه تکرار اجرا گردید. عامل های آزمایشی شامل چهار رقم گندم بهاره بودند. تنش گرما (حداکثر 35 درجه سانتی گراد) با نصب اتاقک های تولید تنش حرارتی روی کرت ها اعمال گردید. بوته های گندم به مدت سه روز متوالی در مرحله ظهور سنبله (H1) ،- و یا در ابتدای تشکیل دانه (H2) ،- در معرض تنش گرما قرار گرفتند. نتایج نشان داد که بین سطوح تنش و ارقام در صفات مورد بررسی اختلاف معنی داری وجود داشت. تنش گرمای کوتاه مدت عملکرد دانه ارقام چمران، مارون، اروند و اترک را به طور میانگین به ترتیب 19.6، 18.6، 17.8 و 11.2 درصد نسبت به شاهد (بدون تنش) کاهش داد. تنش گرما فلیورسانس کلروفیل، محتوای آب نسبی برگ و پایداری غشای سلولی را به طور معنی داری کاهش داد ولی هدایت روزنه ای، سرعت افت کلروفیل و غلظت پرولین افزایش یافت. همبستگی منفی و معنی داری بین افت عملکرد دانه با غلظت کلروفیل کل (r =-0.67 در تنش H1 وr =-0.77 در تنش H2) به دست آمد. فعالیت آنزیمی کاتالاز پراکسیداز و سوپراکسید دیسموتاز در واکنش به تنش H1 یا H2 به طور معنی دار افزایش یافتند. نتایج تجزیه به عامل ها نشان داد، چهار عامل در مجموع 7/86 و سه عامل 86.4 درصد واریانس بین ارقام را به ترتیب در تنش H1 و تنش H2 توجیه کردند. ارقام اترک، چمران و اروند با تداوم فتوسنتز بیشتر، محتوای متابولیت بیشتر و ساز و کار دفاع آنزیمی بهتر نسبت به رقم مارون به تنش گرما را تحمل کردند. می توان گفت که ارقام با سرعت کمتر پیر شدن برگ بعد از مواجهه با گرما و حفاظت آنزیمی بیشتر می توانند در برابر گرما متحمل تر باشند.

    کلیدواژگان: آنزیم های آنتی اکسیدان، تجزیه عاملی، فتوسنتز، گرما
  • حوریه نجفی، سعید نواب پور*، خلیل زینلی نژاد صفحات 653-665

    جیوه به عنوان یک عنصر فلزی سنگین، در آلودگی محیط و ایجاد سمیت و تنش در موجودات زنده نقش دارد. جیوه با تجمع در خاک و جذب به وسیله گیاه به زنجیره غذایی وارد می شود و مسمومیت هایی را در گیاهان و افراد تغذیه کننده بوجود می آورد. بر این اساس آزمایشی به صورت اسپیلت پلات در قالب طرح پایه کاملا تصادفی به صورت کشت هیدروپونیک انجام شد. تیمارهای آزمایشی شامل کلرید جیوه با غلظت های (صفر به عنوان شاهد، 5 ، 10 و 15 میکرومولار) به عنوان فاکتور اصلی و ژنوتیپ‎های گندم نان (مروارید، گنبد و لاین N9108) به عنوان فاکتور فرعی بود. نتایج نشان داد در ژنوتیپ های مروارید و N9108 با تیمار کلرید جیوه میزان بیان ژن کاتالاز و متالوتیونین افزایش یافت و بیشترین میزان بیان این ژن ها تحت تیمار 15 میکرومولار کلرید جیوه (به ترتیب 9.2 و 2.7 برابر نسبت به شاهد) بود. با افزایش غلظت کلرید جیوه کاهش معنی داری در میزان کلروفیل ژنوتیپ های مختلف مشاهده شد. به علاوه کلرید جیوه به طور معنی داری میزان شاخص اکسیداسیون سلولی را در گیاهچه‎های تیمار شده در مقایسه با شاهد افزایش داد. می‎توان نتیجه گرفت رقم مروارید و لاین امید بخش N9108 تحت تنش کلرید جیوه، واکنش بهتری نسبت به رقم گنبد از خود نشان دادند.

    کلیدواژگان: کاتالاز، کشت هیدروپونیک، کلرید جیوه، گندم، متالوتیونین، مرحله گیاهچه ای
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  • Parvaneh Latifi, Abdollah Najaphy *, Leila Zarei Pages 319-329
    Introduction

    Barley (Hordeum vulgare L.) After wheat, maize and rice is the fourth grain, which is cultivated for grain use and has a perennial diploid and polyploid, and has been dispersed throughout the world. The adaptation of cultivars in different environmental conditions in plant breeding programs is of particular importance. Reactions between genotypes and environmental effects are referred to as genotype and environment interaction.The interaction between the genotype and the environment creates complexity in yield prediction and is a challenge for plant production and breeding programs. Methods for reducing the interaction between genotype and environment and increasing performance can be used to select and introduce high-performance and sustainable lines in different regions. Therefore, the aim of this study was to investigate the genotype × environment interaction and adaptability and performance stability of 21 barley genotypes using the analysis of the main and multiplicative effects (AMMI) model. Data related to location and years in the form of integrated environment and data analysis were carried out based on six environments. Then AMMI analysis and calculation of the main components of the interaction effect for all genotypes and drawing of the plot and calculation of ASV stability index was performed using IRRISTAT software.

    Materials and methods

    The present experiment was carried out in randomized complete block designs with two replications during 2014-2015, 2015-2016, 2016-2017 under rain-fed and irrigation conditions (a total of six environments) at the research farm of Faculty of Agriculture, Razi University, Kermanshah, Iran.

    Findings

    The combined analysis of variance for grain yield showed significant differences for year, genotype, genotype × year, year × location and year × location × genotype effects. The results of the analysis of AMMI model showed a significant difference between genotype and environment and four components of the interaction for grain yield were significant. The first and second components in AMMI model accounted for 52.78% and 26.00% of the interaction sum of squares, respectively. Genotypes with high values of the first major components (positive or negative) have a high interaction with the environment, while the genotypes with the first major component near zero have lower interaction. Genotypes 2, 5, 8, 10, 13 and 20 with fewer values of the first component of interaction were more stable than the other genotypes. The value of ASV was obtained from the ratio of sum of squares of IPCA1 (the first component of interaction) to IPCA2 (the second component of the interaction) for each genotype. According to the stability Index, the genotypes 9, 12, 15 were selected with the lowest values of AMMI stability as most stable genotypes. In order to determine sustainable genotypes with general and specific adaptation, AMMI Biplot was used for different locations. The results showed that genotype 2, 5, 8, 10, 13, which are at the center of biplot, have general stability and the genotypes that are closer to any environment the environment have specific adaptability to the environment. Among stable genotypes, genotypes 10 (Roho / 4 / Zanbaka / 3 / ER / Apm / Lignee131 / 5 / Otis), 8 (Baladieldawaia / 5 / AwBlack / Aths // Arar / 3 / 9Cr279-07 / Roho / 4 / DD-14 / Rhn-03) and 2 (Zarjau/80-5151//Skorohod/3/Robur/WA2196-68//DZ40-66) had higher mean grain yield. Therefore, these genotypes can be proposed for using in future breeding programs to introduce new cultivars.

    Conclusion

    Combined analysis of variance showed significant effect of year, genotype and genotype × year interaction for grain yield. The significant effect of genotype indicates the diversity of studied genotypes in terms of grain yield. Among the stable genotypes, genotypes 2, 8 and 10 had also higher grain yield, therefore, it can be suggested that the genotypes can be introduced as new cultivars or for use in future breeding programs. However, it is not appropriate to use a stablity method to identify high-performance and stable genotypes, so, it is recommended to use different methods to assess the stability.

    Keywords: AMMI Stability value, Genotype×environment interaction, Irrigation conditions, Rain-fed conditions
  • Shahin Madadi, Mehdi Rahimi *, Masoud Ahmadiafzadi, Saeid Mirzaei Pages 331-340
    Introduction

    Maize (Zea mays L.) is considered as one of the most important cereals in the field of world production. Water stress due to water shortages and its various forms is one of the main and most common limiting factors of crop yield, especially in arid and semi-arid regions of the world. Therefore, in corn, identification, selection and use of tolerant cultivars against drought stress in order to prevent the reduction of crop yield is considered as one of the most important and essential issues in breeding programs. Breeding of high-yield and good quality cultivars is one of the main goals of the breeding program which requires comprehensive information about the genetic structure of the parents, as well as their general and specific combining ability, the level of heterosis, genes action, and their interaction with each other and the environment. Therefore, the present study was conducted to evaluate the gene effects, heritability and the control of yield and its components in drought stress conditions compared to normal conditions in corn. In order to select suitable breeding methods and take an effective step in the production of high yielding maize cultivars.

    Materials and methods

    In order to estimate the gene action and heritability of important agronomic traits, five S7 maize lines in a 5×5 half-diallel cross with F1 hybrids derived from them in a randomized complete block design with two replications in two normal conditions (irrigation intervals of 5 days) and drought stress (8 days irrigation) were cultivated at the Research Farm of Graduate University of Advanced Technology, Kerman, Iran in 2017. Number of ear, grain number per row, grain row number, grain number per ear, ear length, 100-grain weight and grain yield per plant were evaluated in two conditions. The data were analyzed by analysis of variance and regarding the significance of the variance of treatments, the analysis was performed using Griffing's second method. In order to carry out the diallel analyzes by Griffing's second method in two normal and drought stress conditions and combined analysis of variance was used SAS command.

    Results and discussion

    Combined analysis of variance showed that there was a significant difference between genotypes, environment and genotype×environment interaction for all studied traits, indicating the genetic differences between lines and corn hybrids. The results of combined variance analysis showed a significant interaction effects between general and specific combining ability with the environment, which indicates the different of inheritance of traits in each environment. The results of diallel analysis by second Griffing method under normal conditions indicated that the grain number per row, grain row number, grain number per ear and ear length more controlled by non-additive effects of genes, while these traits more controlled by additive effects of genes under water scarcity conditions.

    Conclusions

    The results of this study showed that although genes with both additive and non-additive effects played a role in controlling the traits, the contribution of each of these effects was different in controlling each of the traits. Also, the control of these traits was different in both normal and drought stress conditions, and the genes controlling these traits differed from environment to environment. The KSC704-S7-7 line showed positive and significant general combining ability for grain yield and most related traits in both conditions which can be used in breeding programs to improve grain yield and increase it. In addition, the P2×P4 cross under water scarcity conditions and the P1×P3 cross under normal conditions, which showed positive and significant specific combining ability for grain yield and most related traits, are introduced as the best hybrids for improvement and increase of maize grain yield for water scarcity and normal conditions, respectively.

    Keywords: Diallel cross, Gene effect, GCA, SCA
  • Marouf Khalili *, MohammadAli Ebrahimi Pages 341-355
    Introduction

    Grain growth in wheat depends on current photosynthesis and stem water-soluble carbohydrates (WSC). In semiarid regions with terminal drought, grain filling in cereals may depend more on stem water-soluble carbohydrates content than on current assimilates. Reduction in grain yield under water deficit condition is attributed to shorter duration of linear grain growth despite increased contribution of stem reserves to grain yield. The amount of stem reserves is measured either by changes in stem dry weight (indirect method) or by stem water-soluble carbohydrates content (direct method). Genotypic variation in the rate and duration of linear grain growth and in percent contribution of stem reserves to grain yield has a little evaluated in cereals and especially in the barley.

    Materials and methods

    The objectives of this study were estimation of genetic diversity and grouping of double haploid barley lines in terms of photosynthetic partitioning in normal and water deficit conditions. Plant materials used in this experiment, include 72 double haploid lines along with Steptoe and Morex parents on a research farm of Mahabad University were studied in a simple lattice design with two replications in normal conditions and water deficit conditions 2016. Irrigation in stress and non-stress treatments was done after 90 mm evaporation from class a pan, depending on the temperature and evapotranspiration until heading stage. In water deficit stress treatment, irrigation was stopped at heading stage. Measuring of understudy traits were done after anthesis stage. In present study leaf partitioning, steam partitioning, spike partitioning, spike to steam ratio, remobilization, remobilization portion in grain yield, thousand kernel white, biological yield, grain yield and harvest index was measured.

    Results and discussion

    Results showed that there was a significant difference between studied genotypes for all traits. Under normal conditions, significant positive and negative segregations for all traits other than biological and in water deficit significant positive and negative segregations for all under study treats were observed, furthermore in both conditions, the highest amount of narrow-sense heritability was calculated for harvest index traits and grain yield. The results of regression analysis of traits affecting grain yield showed that under normal conditions, two traits of 1000 grain weight and remobilization of photosynthetic materials (R2 = 89) identified as The most effective traits on grain yield. Under water deficit conditions, the harvest index, the remobilization portion in grain yield and remobilization (R2 = 0.82) were identified as the most effective traits on grain yield. In normal irrigation conditions, two traits of 1000 grain weight and remobilization of photosynthetic materials had a positive and direct effect on grain yield. However, under water deficit conditions, the harvest index and remobilization had direct positive effect and remobilization portion in grain yield showed a negative and direct effect on grain yield. Based on the results of cluster analysis, genotypes were classified into two groups under normal and three groups in water deficit conditions.

    Conclusions

    In present study photosynthetic remobilization of photosynthetic materials had a positive effect on grain yield variation in both conditions. Therefore, selection of genotypes with the highest amount of photosynthesis accumulation and remobilization could be an effective way to increase grain yield in both conditions. Based on the results of cluster analysis in normal conditions, genotypes located in cluster 1 and under water stress conditions of genotypes located in cluster 2 due to had the highest allocation and remobilization of photosynthetic materials and grain yield are recommended.

    Keywords: Barley, Double Haploid, Genetic diversity, Heritability
  • Negin Mohavieh Assadi, Ehsan Bijanzadeh *, Ali Behpouri Pages 357-369
    Introduction

    Barley (Hordeum vulgare L.) is one of the most important crops in southern provinces of Iran such as Fars province, which is one of the largest barley producing areas in Iran. (Emam, 2011). In crops, the physiological basis of dry matter production depends on the source-sink relationship, where the source is the potential capacity for photosynthesis and the sink is the potential capacity to store or metabolize the photosynthetic products. When the sink is small, higher yield could not be achieved and even if the sink is large, the yield might not be high when the source capacity is limited (Alam et al., 2008; Emam and Seghatoleslami, 2005; Borras et al., 2004(. Drought stress is an important limiting factor which can cause major effect on crop productivity in arid and semi-arid regions of Iran (Ahmadi et al., 2009). Optimizing the source size after anthesis and its utilization by the sink is one of the major factors enhancing the yield potential in crops especially under water deficit conditions (Bijanzadeh and Emam, 2011). The purpose of this experiment was to investigate the effect of defoliation at milk development stage of barley on biochemical traits of barley cultivars under drought stress conditions.

    Material and methods

    In order to evaluation the effect of defoliation and drought stress on biochemical traits and grin yield of barley cultivars, a greenhouse experiment was conducted at College of Agriculture and Natural Resources of Darab, Shiraz University during 2017-2018. The treatments included of two levels of irrigation regimes (full irrigation and cutting off irrigation at milk development stage of barley), four barley cultivars (Zehak, Nimroz, Reyhan, Khatam) and three defoliation treatments included of non-defoliation, defoliation except the flag leaf and defoliation except the flag leaf and the penultimate leaf, which laid out as a factorial experiment based on a randomized complete block design with three replicates. At crop maturity, plants were harvested to measure spike length, 100- grain weight, biological yield, harvest index and grain yield and two weeks after applying drought stress treatment, chlorophyll a, b, carotenoid, catalase, and peroxidase contents were measured.

    Results and discussion

    The results showed that drought stress, cultivars and defoliation interaction had a significant effect (p≤0.01) on chlorophyll a, carotenoid, peroxidase, catalase, and grain yield but it was not significant for chlorophyll b. The results showed that drought stress caused 56.6 % and 24.2 % reduction in grain yield and chlorophyll b, respectively. In agreement to our results, Rahbarian et al. (2011) reported that variation in photosynthetic pigments and grain yield affected by drought stress level, genotype and growth stages of crop. Also, interaction effect of drought stress and defoliation showed 87.71% decrease in the amount of carotenoid. Amini and Hadad (2013) asserted that carotenoid content decrease sharply when plants exposed to drought stress. Defoliation except the flag leaf and penultimate leaf caused 98.76% increase in catalase in Reyhan cultivar, under drought stress. Likewise, defoliation except the flag leaf increase the peroxidase enzyme in all of the cultivars except the Nimroz. Similar to our results, Zhang and Kirkham (1995) and Kafi and Damghanii (2000) declared that catalase and peroxidase activity increased in some wheat cultivars when plants exposed to drought stress and this increasing depended on drought stress level and type of cultivar.

    Conclusion

    It was concluded that, under water stress, increasing the enzymatic activity by defoliation could play a vital role in barley grain yield especially in Reyhan barley cultivar.

    Keywords: Carotenoid, Catalase, Defoliation, Flag leaf, Peroxidase
  • Laia Moradbeigi *, Ahmad Gholami, Amirhossein Shirani Rad, Hamid Abbasdokht, Hamidreza Asghari Pages 371-386
    Introduction

    Canola oil seed species currently hold the third position among oil seed crops and has lowest saturated fatty acids content (Ashraf and Mcneilly 2014). When commercial production was first considered in Iran, site location and planting date were thought to be the two most important cultural decisions. A long term drought stress effects on plant metabolic reactions associates with, plant growth stage, water storage capacity of the soil and physiological aspects of plant. Generally, the number of seed per plant, number of seeds per pod and also seeds weight are considered the yield components of canola (Angadi et al., 2003). A study by Kajdi and Pocsai (1993) on the effects of irrigation on 21 rapeseed cultivars showed that, as irrigation frequency increased, the seed yield increased as well. Indeed, they noticed the high seed yield only in the cultivars with high levels of erucic acid and glucosinolate. Moreover, it has been reported that drought or heat stress during flowering and seed filling stages could stop the flowering and caused decrease of seed formation, oil percentage and the seed yield to decrease (Johnston et al., 2002). If cultivars could be selected in a way that produce an acceptable economic yield in less watering condition and are more stress tolerant under the stress intensity conditions, they would be practically very useful for developing rapeseed cultivation in such regions.

    Materials and methods

    In order to study the effect of delayed planting and drought stress on grain yield grain component, saturated and unsaturated fatty acids, oil content and glucosinolate of seeds and proline content of rapeseed, a field experiment was conducted as split-plot arrenged in a Randomized Complete Block Design (CRBD) with three replication in Seed and Plant Improvement Research Institute of karaj in 2014-2016. Experimental treatments were included sowing dates in two levels included: 20th of October (normal cultivation) and 5th of November (delayed cultivation), Irrigation in 2 levels includes: normal Irrigation (control) and drought stress (irrigation withholding in pod formation) as well as hybrids and hybrids Rapeseed autumn included: Neptune, Elvise, Okapi, Tassilo, GKH0224, GKH2624 and GKH3705.

    Results and discussion

    The results of the experiment showed that planting date, irrigation and cultivar were significant on all traits Except for eicosenoic acid, Results showed that delaying the planting date decreased pod number per plant, 1000-grain weight yield, oil content, eicosenoic acid proline, whereas behenic acid and seed glucosinolate were increased. The highest oil content (45.59%) was in normal irrigation and normal cultivation, And the lowest (42.16%) was observed in irrigation withholding in pod formation stage and delayed cultivation. The highest content of proline (21.59 mg.g. Fw) was observed in normal cultivation and GKH3705 cultivar. The cultivar of GKH3705 was the most appropriate in terms of yield and its components, oil content, saturated and unsaturated fatty acids and glucosinolate of seeds. According to the results, it seems that normal cultivation and GKH3705 cultivar under without stress and drought stress can be recommended as the best treatment for the benefit of rapeseed production in the Karaj region.

    Conclusions

    According to the results of this experiment, the most suitable planting date for the studied cultivars of canola is 20th of October in Karaj area. Among the cultivars under study, GKH3705 also produced the highest grain yield in normal and delayed planting, as well as in normal irrigation and stress conditions. In terms of grain and oil production potential and the composition of unsaturated fatty acids are in the optimum level.

    Keywords: Fatty acid, Glucosinolate, Irrigation withholding, Proline, Sowing dates
  • Hamdollah Eskandari *, Ashraf Alizadeh-Amraie, Abdullah Javanmard Pages 387-399
    Introduction

    One of the most common ways to increase the quality of cereal forage is to mix them with legume family plants. Growing of crop mixtures with legumes, which is named intercropping, can amplify the forage quality of livestock diet. The main obstacle for agriculture in arid and semi-arid areas is the limitation of available water resources. Thus, the management of limited water for irrigation is crucial. Several patterns have been introduced for saving water in agricultural systems. Partial root-zone irrigation is a method which has been considered in recent years for saving water. In this irrigation method, half of root system is irrigated and other half is exposed to dry soil, so that the irrigation water amount is much lower than that of conventional irrigation. Increasing water use efficiency is one of the most important benefits of partial root-zone irrigation, where a large amount of water saving and low yield reduction is occurred by partial root-zone irrigation. The aim of this experiment was to investigate the quantity and quality of forage produced in intercropped wheat and Persian clover under partial root-zone irrigation condition.

    Materials and methods

    The experiment was conducted as a field experiment during 2016-17 growing season in Lorestan province. A two-factor factorial experiment based on randomized complete block design with three replications was employed to compare the treatments. The fist factor was irrigation (conventional irrigation (I1) and partial root zone irrigation (I2)) which was applied after seedling establishment. The second factor was planting pattern including sole wheat, sole Persian clover, within-row intercropping and between-row intercropping. Water consumption was measured during growing period. At harvest time, forage yield and quality (in terms of CP, DDM, CF, NDF, and ADF) were determined. Water use efficiency was measured for forage yield and. Land equivalent ratio was used to evaluate the advantage of intercropping.

    Results and discussion

    The forage yield of all planting patterns was negatively affected by partial root-zone irrigation. Dry matter production of sole wheat, sole Persian clover, within-row intercropping and alternate-row intercropping was reduced 16%, 15%, 9% and 8% by partial root-zone irrigation, respectively. LER was more than one (1.024) only under partial root zone irrigation which was 8.8% more than that of conventional irrigation. In other word, for forage production, intercropping of wheat and Persian clover has advantage only under partial root zone irrigationThe quality of forage produced in intercropping reduced by partial root-zone irrigation method. Digestible dry matter (DDM) of wheat-Persian clover intercropping reduced by 7% with applying partial root-zone irrigation. Partial root-zone irrigation reduced crude protein content of sole Persian clover, within-row intercropping and alternate-row intercropping by 15%, 14% and 16%, respectively. ADF and NDF of forage produced in within-row and alternate-row intercropping of wheat and Persian clover was increased 6% and 7% by applying partial root-zone irrigation, respectively. Persian clover had the highest WSC. The lowest WSC was achieved in sole cropping of wheat. However, Persian clover had the lowest crude fiber (CF) which was not significantly difference with alternate-row intercropping of wheat and Persian clover. The highest (104.19 kg mm-1 ha-1 dry matter) and lowest (43.5 kg mm-1 ha-1 dry matter) water use efficiency for forage production was achieved in sole wheat under partial root-zone irrigation and sole Persian clover under conventional irrigation, respectively. Partial root-zone irrigation improved water use efficiency of all planting patterns for forage production. Within-row intercropping of wheat and Persian clover had highest (84.94 kg. mm-1. ha-1) water use efficiency for digestible dry matter under partial root-zone irrigation method which was 3 times more than that of conventional irrigation. Persian clover with partial root-zone irrigation produced highest crude protein (kg ha-1) for the consumption of each unit of water. Except sole wheat, water use efficiency (for crude protein production) of other planting pattern improved about 50% with partial root-zone irrigation. Positive effects of wheat shading on Persian clover helped Persian clover to maintain its leaf water content, showing that Persian clover was less affected by partial-root zone irrigation in intercropping and was able to produce more dry matter, resulting in higher DM of intercropping.Increasing ADF and ADF of sole and intercropped forage showed that more fiber was accumulated in plants with partial root-zone irrigation, resulting in the reduction of forage quality

    Conclusion

    Compared to conventional irrigation, partial root-zone decreased forage production of sole and intercropping patterns. However, water consumption of wheat and Persian clover significantly decreased in all cropping stands, resulting in the increase of water use efficiency on the basis of forage quantity and quality. As a final remark, our experiment has confirmed the hypothesis that partial root-zone irrigation could be a good irrigation management of wheat and Persian clover intercropping for forage production in areas with a sever limitation in irrigation water supply.

    Keywords: Drought stress, forage production, land equivalent ration, water use
  • Ahmad Pourjamshid *, Mehrdad Ghaysari, Ali Sharifi Nick, Faisal Salemi Pages 401-412
    Introduction

    Wheat (Triticum aestivum L.) is considered as the major cereal crop in the world in respect of the cultivated area and total production. Drought is a polygenic stress and is considered as one of the most important factors limiting crop yields around the world. Most of the Iranian soils, have a high pH and calcareous nature, and micronutrients solubility in these soils is low. Micronutrients plays a critical role in increasing plant resistance to environmental stresses. Iron as a micronutrient, is critical for chlorophyll formation and photosynthesis and is important in the enzyme systems and respiration of plants. Zinc is a ubiquitous micronutrient. It is required as a structural and functional component of many enzymes and proteins, and increases the yield and yield components of wheat. Manganese as a micronutrient, is necessary in photosynthesis, nitrogen metabolism and to form other compounds required for plant metabolism.

    Materials and methods

    To study the effect of micronutrients foliar application on some physiological and agronomic traits of bread wheat (Triticum aestivum L.) under complete irrigation and terminal drought stress condition, an experiment was conducted as split-plot based on randomized complete blocks design with four replications in Ramhormoz city located in south-western Iran. The experimental factors were included drought stress in two levels of complete irrigation (non-drought stress) and irrigation interruption from the beginning of flowering stage to the physiological ripening (terminal drought stress) as the main factor, and micronutrients foliar application in six levels of non-foliar application (control), foliar application by water, iron, zinc, manganese and iron + zinc + manganese (each 3 lit.h-1) as the sub factor. Solutions for foliar application were prepared by using Iron chelate (6%), Zinc chelate (7.5%) and Manganese chelate (7%). The measured traits included leaf chlorophyll index, leaf proline content, cell membrane stability index, grain yield, biological yield, harvest index and grain protein content. To determine the leaf chlorophyll index used of chlorophyll meter digital. To determine the leaf proline content, method of Bates et al. (1973) was used. To determine the cell membrane stability index used of method Lutts et al. (1996). The grain yield was determined at maturity stage and through the harvest of all spikes from the level of 1 m-2 per plot and after removing 0.5 m from the beginning and end respective planting rows (rows 5 and 6). To measure the biological yield at maturity stage, after removing 0.5 m from the beginning and end respective planting rows (rows 5 and 6) from the level of 1 m-2 per plot all the plants were harvested and weighted for each plot separately. The harvest index was determined by the equation GY/BY×100. The grain protein content was calculated as N% × 5.7 on a dry weight basis. N% in grain was determined by the Kjeldahl method according to A.A.C.C. (2000). Analysis of variance was performed using general linear model (GLM) procedure of statistical analysis system (SAS version: 9.3). The means were analyzed using the least significant difference (LSD) method at P=0.05 (LSD 0.05).

    Results and discussion

    Results showed that the terminal drought stress decreased significantly traits of leaf chlorophyll index, cell membrane stability index, grain yield, biological yield and harvest index except for leaf proline content and grain protein. However, micronutrients foliar application of iron, zinc and manganese increased significantly the measured traits in both non-stress and terminal drought stress condition. Meanwhile, application of zinc spray showed the greatest effect in reducing the damage caused by terminal drought stress on measured traits.

    Conclusions

    In general, the use of micronutrients, especially zinc, as foliar application, can reduce the harmful effects caused by terminal drought stress and improve the physiological, agronomic traits and grain protein content of bread wheat in Ramhormoz region.

    Keywords: Environmental stresses, Iron, manganese, Zinc
  • Ali Nakhzari Moghaddam *, Naser Samsami, Ali Rahemi Karizaki, Esmaeil Gholinezhad Pages 413-423
    Introduction

    Drought is considered to be a major threat to soybean production worldwide and yet our current understanding of the effects of drought on soybean productively is largely based on studies on above-ground traits. The symbiotic interaction between soybean and rhizobia facilitates atmospheric nitrogen fixation, a process that provides essential nitrogen to support plant growth and development. Symbiotic nitrogen fixation is important for sustainable agriculture, as it sustains plant growth on nitrogen-poor soils and limits fertilizer use for crop nitrogen nutrition (kunert et al., 2016). Application of mycorrhiza and nano oxide of Zn+Fe increased grain yield by 35.9% as compared with non-mycorrhiza, non-foliar application of nano oxide under severe water limitation. It seemed that mycorrhiza and nano oxide of Zn+Fe application was usable for profitable safflower production under water limitation condition (Seyed Sharifi and Seyed Sharifi, 2017). The aim of this study was to determine the effect of different levels of drought stress in inoculation with mycorrhiza fungi and Rhizobium bacteria on physiological traits and grain yield of soybean.

    Materials and methods

    In order to investigate the effects of water deficit stress and inoculation with mycorrhiza fungi and rhizobium bacteria on physiological traits and seed yield of soybean, an experiment was conducted as a factorial split plot design based on a randomized complete block design with three replications at research farm of agricultural highschool of Urmia during 2017. The main factor was three water deficit stress levels such as optimum, moderate and severe (irrigation after 70, 110 and 150 mm evaporation from class A evaporation pan), subplots was inoculation with mycorrhiza fungi including without mycorrhiza, and inoculation with Funneliformis mosseae and Rhizophagus intraradices and rhizobium bacteria inoculation in two levels of non inoculation and inoculation with Bradyrhizobium japonicum. In this experiment, Kowsar (new cultivar of soybean) was used. Row spacing was 50 cm and plant spaces on each rows was 10 cm. Each plots contained four rows with four meter long. To determine the seed yield, two border rows and 0.5 m from both sides of middle rows were excluded. For yield components, 10 plants were randomly collected and traits of leaf temperature, relative water content, chlorophyll a., chlorophyll b, proline, electrolyte leakage and seed yield were determined.

    Results and discussions

    By increasing water deficit stress without inoculation with mycorrhiza increased leaf temperature but decreased relative water content and chlorophyll b. By increasing water deficit stress without inoculation with bacteria leaf temperature was increased but chlorophyll b and seed yield was decreased. Inoculation with bacteria with or without inoculation with mycorrhiza decreased leaf temperature. This conditions was existed for relative water content, chlorophyll a and b content. Inoculation with bacteria and mycorrhiza specially F. Mosseae caused that maximum seed yield was obtained with 443.2 g m-2. Proline and electrolyte leakage in treatment of severe water deficit stress and non inoculation with mycorrhiza and bacteria was greater than other treatments. Minimum proline and electrolyte leakage observed in treatment of optimum irrigation and inoculation with bacteria and mycorrhiza F. mosseae.

    Conclusion

    In addition, water deficit stress caused unsuitable conditions for soybean that led to loses of seed yield but inoculation with bacteria and mycorrhiza reduced unsuitable conditions and soybean growth was improved.

    Keywords: Chlorophyl, Electrolyte leakage, Leaf Temperature, Proline
  • Mahdi Saheb Hasan, Yahya Selahvarzi *, Jafar Nabati, Majid Azizi Pages 425-440
    Introduction

    Calendula officinalis, the pot marigold, ruddles, common marigold is a plant in the genus Calendula of the family Asteraceae. It is probably native to southern Europe. It is also widely naturalised further north in Europe and elsewhere in warm temperate regions of the world. Calendula is applied to the skin to reduce pain and swelling and to treat poorly healing wounds and leg ulcers. It is also applied to the skin for nosebleeds, varicose veins, hemorrhoids, inflammation of the rectum, ear infection, gum disease, peeling lips, diaper rash, vaginal yeast infection, and inflammation of the lining of the eyelid (conjunctivitis). Essential oil of calendula has been used as an insect repellant. One of the major limiting factors for plant growth is water availability. Drought affects many aspects of plant physiology to reduct plant growth and photosynthesis. Mycorrhiza fungi colonize the roots of host plants and perform absorption services for the plant. Various studies have demonstrated that plants associated with Mycorrhiza fungi show increased uptake of various materials from the soil, including water, and macro and micronutrients. As a result, VAM fungi improve their host plants’ ability to grow under conditions of drought stress or in mineral deficient soils. The bacteria that can promote plant growth, that is, include those that are free-living, those that form specific symbiotic relationships with plants, bacterial endophytes that can colonize some or a portion of a plant’s interior tissues. Growth-promoting bacteria may promote plant growth directly usually by either facilitating resource acquisition or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogenic agents on plant growth and development, that is, by acting as biocontrol bacteria.

    Material and methods

    This research was carried out in order to investigate the effect of Mycorrhiza fungi and some growth-promoting bacteria on Calendula officinalis var. Pacific beauty orange under drought stress conditions in 2017-2018 in Faculty Agriculture, Ferdowsi University of Mashhad in a factorial experiment based on completely randomized design with 4 replications. The first factor was drought stress in two levels (100 and 50% crop capacity) and the second factor was the use of bio fertilizer in 8 levels including: Pseudomonas fluorescens (Ps), 2. Azotobactore chroococcum (Az), 3. Mycorrhizal fungus (M), 4. Ps + M, 5. Az + M, 6 Ps + Az, 7. Az + Ps + M, 8. Control (non-use of bacteria and fungi). At the end of the experiment morphophysiological and biochemical traits of the plant were measured. The height and diameter of the flower were measured by digital caliper. Number of flowers, number of leaves and number of lateral branches were counted. shoot and root fresh weight was weighed after the separation of the plant from the pot in a laboratory with a digital scale of 0.001. then plants were ejected from the pot, root length was recorded. The maximum efficiency of the photocysteine II in the plant was measured by a fluorometer (FL-OS model) and for measuring chlorophyll index (SPAD-502) using Spad. The relative leaf water content, ion leakage and antioxidant capacity were measured.The statistical analysis of the test data and the comparison of the averages at the probability level of 5% error based on the LSD test was performed using JMP-8 statistical software and drawing charts with Excel 2010 software.

    Results and disscation

     The results showed that drought stress caused a decrease in growth traits in Calendula. So, by decreasing soil capacity from 100 to 50% FC, number of leaves, number of flowers, flower diameter, shoot and root fresh weight, number of lateral branches, Spad and relative leaf water content decreased and Antioxidant capacity increased compared to control treatment. Application of growth stimulating bacteria resulted in improved traits measured in the plant under stress and non-stress conditions. Application of Pseudomonas fluorescens alone or in combination with mycorrhizal fungus under stress conditions (50% FC) resulted in improved growth characteristics in Calendula plant. In terms of number of leaves, number of flowers, flower diameter, number of lateral stems and Spad, improved by application of Pseudomonas fluorescens alone in soil or its combination with mycorrhizal fungus under stress conditions. PGPR directly affects plant growth by facilitating the availability of nutrients such as nitrogen, phosphorus and iron. These nutrients are critical to plant biochemistry, and without them plant growth is limited. While nitrogen, phosphorus and iron may be abundant in the soil, they are often found in a form the plant can’t utilize. PGPR convert those nutrients to the form the plant can use. Actually, PGPR can produce plant hormones like auxins, gibberellins and cytokinins that stimulate plant root and shoot growth in exchange for food sources from the plant. Also, Mycorrhiza fungi can help plants to cope with the detrimental effects of soil water deficit acting, directly or indirectly, on plant functionality both above- and belowground. At the levels of both leaves and roots, the osmotic stress usually caused by drought is counteracted by mycorrhizal plants through biochemical changes that mostly include increased biosynthesis of metabolites (mainly proline and sugars) that act as osmolytes. These compounds contribute to the lowering of the osmotic potential, and in turn, of the leaf water potential. Finally, it seams that the use of Pseudomonas fluorescens in soil alone or in combination with mycorrhizal fungi under drought stress conditions can improve plant growth and increase plant efficiency under drought stress conditions.

    Keywords: Electrolyte leakage, Maximum efficiency of photosystem II, Number of flowers, Percentage of antioxidant activity, Relative humidity content
  • Abolfazl Baghbani, Zohrab Adavi * Pages 441-453
    Introduction

    Water and fertilizers are the main determinants of the level of agricultural production in the world. Iran's climate is predominantly dry and semi-arid, and the availability of water is a major problem in these areas. Water stress significantly changes the metabolism of plants and reduces the growth and photosynthesis and ultimately the performance of plants. In such a situation, drought management is an urgent necessity. Plants and cultivars with less water requirements are one of the most effective ways to manage water. Millet can be considered as a cost-effective product (cereals, fodder and oilseed) in the context of water scarcity due to its significant adaptation to a wide range of climatic conditions. In addition, in order to efficiently manage water use in agriculture, the use of agronomic techniques, such as the application of bio-fertilizers or the strengthening of biological conditions in the soil, may reduce the effects of water stress and less use of chemical fertilizers for sustainable agriculture and human nutrition be effective.

    Materials and methods

    In order to investigate the effect of deficit water stress and application of growth promoting bacteria on morphological, physiological traits, quantitative and qualitative yield and oil compounds of two millet species, an experiment was conducted as split factorial based on complete randomized block design with four replications in research farm of Fereydunshahr, Esfahan province in 2016. In this experiment, deficit water stress were considered as the main plots with three levels (100, 75 and 50 percent of plant water requirement) while application of growth promoting bacteria (with three levels including control, using 1 or 0.5 L.ha-1 Azotobacter chroococcum and Azospirillum brasilenseas seed inoculation) and two millet species (including Golbaf and Bastan) were arranged as factorial sub plots.

    Findings

    In this experiment, water deficit stress significantly reduced stem diameter, biological yield and seed, protein and oil, and its quality in millet. The application of bio-fertilizers could reduce the adverse effects of water stress on the above characteristics in both millet varieties and improve the quality of the oil in such a way that the use of one and a half bio fertilizers, respectively, increased grain yields (6.66 and 19/19%) in irrigation treatments (12.29% and 28.76%) in mild stresses (31.73% and 45.77%) in severe dehydration treatments. In mild stress (75% water requirement), as well as application of one litter of bio-fertilizer in the ancient cultivar, produced the highest quality (oleic and linoleic) oil content while reducing water consumption Also, ancient cultivar had superiority in terms of biological yield and grain and unsaturated fatty acids in different irrigation regimes, with and without bio-fertilizer application.

    Conclusion

    Regarding the increase in the amount of oleic acid, indicating the stability to the temperature and quality of the oil for frying food, and the higher percentage of linoleic fatty acid, indicates the improvement in the value of oil in direct feeding, mild water stress treatment (75% water requirement) Along with the application of one liter of biofertilizer in the ancient cultivar, while reducing water use, the highest quality (oleic and linoleic) was produced.

    Keywords: Water Stress, Fatty acid, Azotobacter, Azospirillium, Qualitative traits
  • Fateme Mohtashami, MahmoodReza Tadayon * Pages 455-469
    Introduction

    Drought stress is a major environmental constraint which inhibits the growth of plants and limits crop production. Nowadays, the application of antioxidants and plant growth regulators has discussed for decreasing the negative effect of different stresses. Ascorbic acid and jasmonic acid have substance caused witch the resistance to biotic and abiotic stresses. Ascorbate is a major metabolite in plants. It is an antioxidant, in association with other components of the antioxidant system, protects plants against oxidative damage resulting from aerobic metabolism and photosynthesis. Jasmonic acid (JA) is a plant-signaling molecule that shows a wide range of plant responses, with effects at the morphological to molecular levels. Many morphological, physiological, and biochemical processes occurring within the plants can be regulated by JA Previous studies have documented that foliar application of JA and Ascorbic acid could modulate plant physiological responses towards abiotic stress tolerance. Considering the importance of safflower plant in terms of quantity and quality of oil, it seems that increasing the yield per unit area under low irrigation conditions is a suitable way to increase the production of this plant so the aim of this study is evaluation of the effect of foliar application of jasmonic acid and ascorbic acid on grain yield, yield components, oil percentage and fatty acids composition of safflower genotypes under deficit irrigation regimes.

    Material and methods

    The experiment was set out in a split plot factorial in a completely randomized block design with three replications at Shahrekord University Agricultural Research Station during spring planting season 2017. The main factor as deficit irrigation consisted of three levels of irrigation of 100%, 75% and 50% of the plant's water requirement of safflower and sub-factor including safflower genotypes including Sinai, Isfahan local and Faraman and foliar application with three levels including (control, foliar application of jasmonic acid with 0/5 mM concentration and foliar application of ascorbic acid with 20 mM concentration.

    Results and discussion

    Results indicated that deficit irrigation tratments caused a significant reduction in height plant, head number per plant, number of seed per head, seed thousand weight, seed yield, oil percentage, unsaturated fatty acids contains linoleic acid and oleic acid. The lowest values of seed yield (1382kg.ha-1) and oil percentage (26/67) were obtained in treatment of 50 %plant water requirement and the highest seed yield (1635 kg.ha-1) and oil percentage (27.21kg.ha-1) were aachived in 100 % plant water requirement. There was a significant difference between safflower genotypes, so the highest seed yield (1676 kg.ha-1) and oil percentage (27.82) were obtained in Sina genotype and the lowest seed yield (1341kg.ha-1) and oil percentage (27.66) were belonged to Local Isfahan genotype. The interaction of deficit irrigation tratment × genotypes were significant on height plant, the unsaturated oleic acid content and the saturated fatty acid content palmitic acid so that the highest of height plant (91.99 cm) and oleic acid content (15.5 percentage) was recorded in 100% of the plant's water requirement conditions and sina genotyp but the highest content of palmitic acid (10.37percentage) was recorded in 50% of the plant's water requirement conditions and sina genotype. Jasmonic acid and ascorbic acid treatment increased the grain yield, yield components, oleic acid and linoleic acid content and reduced the palmitic acid and stearic

    Conclusion

    The results showed that significant difference between genotypes and foliar applicaton treatments, such as the content of unsaturated fatty acids, can be used for the selection of superior genotypes for economic production and commercial cultivation and reduce the adverse effects of deficit  irrigation stress in the field conditions.

    Keywords: Height plant, Linoleic acid, Oil percentage, Oleic acid
  • Ali Zarei, Jafar Masoud Sinaki *, Majid Amini Dehaghi, Ali Damavandi Pages 471-489
    Introduction

    Drought is a major environmental stress affecting plant morphology, physiology, and biochemistry. Two management strategies for controlling drought stress include the use of nutrients and planting resistant plants. Chitosan, known as elicitors, is considered a natural biopolymer modified from chitin, which is the main structural component of squid pens, cell walls of some fungi and crab shells. Nanotechnology provides a new interdisciplinary venture into agriculture and food sciences by converging science and engineering. In addition, nanoparticles have potential applications in agriculture system, viz., the pollutants detection, plant diseases, pests, and pathogens, controlled delivery of pesticide, fertilizers, nutrients, and genetic material, and can act as nano architects in forming and binding soil structure. Sesame (Sesamum indicum L.) is a source of excellent vegetable oil (35-63%). Sesame is considered as drought tolerant crop, the productivity is heavily affected by severe drought stress mainly when it occurs during anthesis. Restricted water resources are considered as a limiting factor for irrigation applications around the world. Therefore, the present study aimed to evaluate the changes in the quality and yield traits of two sesame genotypes under drought stress and foliar application of chitosan and phosphorus nano-chelate in second cultivation.

    Material and methods

    The present study was conducted to investigate the changes in the quality and yield traits related to two sesame genotypes under irrigation cut-off and foliar application of chitosan and phosphorus nano-chelate in the second cultivation at research field of Shahed University in Tehran, Iran, during 2015-16 and 2016-17. The experiment was conducted during a two-year factorial split plot experiment based on completely randomized block design with three replications. The research farm is located at geographical characteristics of latitude 31° and 36’ and longitude 48° and 53’ and the height of this area from sea level is equal to 1050 m. The experimental factors including irrigation treatments at normal irrigation as control (non-stress), mild stress (irrigation cut-off at 50% seed ripping) and severe stress (irrigation cut-off at 50% flowering) were in the main plots and spraying treatments including non-spraying (control), phosphorus nano-chelate (2 ppt), chitosan (3 g.L-1), and the combination of phosphorus nano-chelate + chitosan and Oltan, and Naz single branch sesame cultivars were in the subplots. Number of capsules per plant, number of grain per plant, 1000-grain weight, grain yield, biological yield, oil percentage and yield, and fatty acids composition (oleic, linoleic, palmitic, and stearic contents) was investigated.

    Result and discussion

    The results showed that the highest 1000-grain weight was obtained in the first year of experiment and Oltan genotype (3.10 g) and the lowest mean was in the first year in Naz single branch genotype (2.51 g). The highest grain yield was observed in the second year of the experiment under without stress and mild stress conditions (irrigation up to seed ripening) and foliar application of phosphorus nano-chelate alone or combined with chitosan. In general, between different levels of irrigation treatments, severe stress (irrigation up flowering) resulted in a significant reduction in the grain yield, but mild drought stress (irrigation up to seed ripening), especially in terms of using chitosan and nano-fertilizer compounds, had a good grain yield. In the interactions effects of the year in drought stress, the highest seed oil percentage was obtained in the non-drought stress (normal irrigation) during the second year of the experiment (57.02%) and the lowest mean of this trait was observed in the second year under severe drought stress condition. Compared to the two cultivars, the highest oil yield was in Naz single branch cultivar (858.4 kg/ha) and the lowest mean of Oltan cultivar (731.7 kg/ha) was observed. The highest amount of saturated fatty acids (palmitic and stearic) was achieved in Oltan cultivar under non-foliar aplication. In contrast, the lowest content of linoleic fatty acid (unsaturated fatty acid) was observed in this treatment. In general, the application of phosphorus nano-chelate with chitosan increased the quantitative and qualitative characteristics of sesame seed yield and resulted in increased growth and quality growth factors in drought stress conditions. Summer planting of sesame plant is recommended in warm and dry climatic conditions (with end session drought stress) along with chitosan and phosphorus nano fertilizer.

    Conclusion

    Based on the aim of this research, the results showed that planting both Oltan and Naz single branch cultivars in the south Tehran climatic after wheat harvesting (as the second crop) had favorable results for grain and oil yield. In general, the results showed that co-application of phosphorus nano-chelate and chitosan fertilizers under mild drought stress (irrigation up to seed ripening) resulted in the moderate negative effect of drought stress and produced grain and oil yield. Also, the cultivation of this plant in warm and dry climates (similar to southern Tehran) under the mentioned conditions (co-application of phosphorus nano-chelate and chitosan fertilizers) is recommended under limited irrigation conditions (end of season drought stress).

    Keywords: Drought stress, Fatty acids, Foliar application, Grain yield, second cultivation
  • Ebrahim Khalilvand Behrouzyar * Pages 491-502
    Introduction

    Drought is one of the most important causes of decline in agricultural productivity worldwide (Kamanga et al., 2018). TiO2 is one of the materials that nowadays, its properties have been reported to reduce environmental impact (Rosi and Kalyanasudaram, 2018). TiO2 with increasing Activity of Ps II Light Reduction, activity of chloroplast photophosphorylation, rubisco enzyme, nitratreduktase enzyme activity, catalasea and peroxidase and improving the content of some essential elements in plant tissues, increases the yield of different products (Khater, 2015). Also, by reducing free oxygen radical and malondialdehyde and increasing the antioxidant enzymes reduces the negative effects of stress (Zheng, 2007).In the study of the effect of nano-TiO2 spraying on some of the agronomy characteristics in wheat, 0.02% nano-TiO2 foliar application under drought stress conditions compared to non-foliar application was increased seed yield by 23% (jaberzadeh et al., 2010). Considering that a large part of cultivated land in Iran has semi-arid climatic conditions and because of its special geographical position, in most parts of it, important abiotic stress such as drought, salinity and temperature, decrease the yield and, in some cases, also has led to failure in agriculture, therefore, achieving the highest yield with the least possible water consumption in the shortest time with the use of nano-compounds such as TiO2  against breeding methods that are often long-term and cost-intensive, it seems necessary that the present research also aims to achieve goals such as evaluating and identifying important physiological traits of sweet ear weight under water deficit stress and application of the above compound.

    Material and Methods

    In order to investigate the effects of water deficit stress and nano-TiO2 foliar application on ear weight and some of biochemical characteristics in sweet corn plant, an experiment was conducted in split plot form based on RCBD in three replications at the Research Station of the Islamic Azad University, Tabriz Branch, during growing seasons of 2017. Treatments were water deficit stress in three levels contained: 50, 75 and 100% filed capacity (FC) as well as the nano-TiO2 foliar application in four levels contains: non application (control), 0.01, 0.03 and 0.05%. Field capacity was determined from the pressure plate machine. TiO2 foliar application on the shoot was performed three times during the growing season and in the stages of 8-10 leaf, tasseling and grain filling. Irrigation is done according to the needs of the canopy and depending on the weather conditions of the area and from 8-10 leaves stage, regarding irrigation intervals, treatments were applied. Peroxidase enzyme activity by Hemeda and Klein method (1990), malondialdehyde  according to the Heath and Packer method (1968), amount of Soluble carbohydrates by phenol-sulfuric acid method (Dubios et al., 1956), and amount of leaves proline according to the Bates et al., (1973) method were measured. The ear weight was calculated in gm-2. Analysis of variance, and mean comparison with MSTAT-C software were used. The means of the treatments were compared using the Duncan’s test at P< 0.05 and Charts are plotted by the EXCEL program.

    Results and discussion

    The analysis of varianceshowed that the TiO2 foliar application on peroxidase and interaction effect between TiO2 foliar application and water deficit stress on malondialdehyde, soluble carbohydrates, proline and Ear weight was significant (p<0.01). According to this study, the concentration of 0.01% of TiO2 foliar application, increased the activity of peroxidase enzyme, but the important point is that with increasing TiO2 concentration, the activity of this enzyme decreased. Since the increase in peroxidase activity is related to the rate of peroxidation of membranes, reducing malondialdehyde levels in treated plants indicates that the activity level of peroxidase activity is sufficient to collect active oxygen species to prevent damage to the membrane. 0.01% of TiO2 foliar application under conditions of 50% moisture content increased the amount of soluble carbohydrates and proline, which was reduced by increasing the amount of this compound and increasing the available moisture content. 0/01% TiO2 foliar application under full irrigation conditions with an average of 744 gm-2 and no irrigation at 50% moisture content with an average of 457 gm-2 had the lowest grain yield, which showed a decrease of 38.5% that compared with 0.03% nano- TiO2 in the same irrigation and 0.01% nano- TiO2 in 75% moisture content was not significantly different.
    The results of this study showed that TiO2 foliar application increased the activity of peroxidase enzyme, soluble carbohydrates, proline and decreased malondialdehyde enzyme activity under water deficit stress in sweet corn. Furthermore, the nano-TiO2 also increased the ear weight in all treatments, which indicates the positive effects of this composition on the plant. According to the research objectives, the use of nano- TiO2 in order to increase yield under minimum water use conditions can be a good alternative to breeding methods that are often long-term and cost-effective

    Keywords: Malondialdehyde, Peroxidise, Proline, Soluble carbohydrates
  • Azam Roumani *, Abbas Biabani, Ali Rahemi Karizaki, Ebrahim Gholamalipour Alamdari, Abdollatif Gholizadeh Pages 503-517
    Introduction

    Drought stress is considered as one of the most important environmental problems in agriculture and the growth of plants. The persistent shortage of water causes early aging of the leaves of plants. During this process, the chloroplasts are destroyed and photosynthesis activity sharply reduced. The adaptation of plants to drought stress is the result of a change in many morphological and biochemical mechanisms which lead to changes in plant growth rate, stomatal conductivity, photosynthesis process speed, and enzyme activity. The ability of plants to compromise in environmental stresses depends on the type, intensity and duration of stress and plant species. Salicylic acid is a phenolic compound known as an important molecular signal in plant fluctuations in response to environmental. Also alters a number of metabolic pathways including synthesis, oxidation and some biological activities including respiration, photosynthesis and absorption. Polyamines (PA) are a group of phytohormone-like aliphatic amine natural compounds with aliphatic nitrogen structure which are present in whole living organisms including plants. They play a role in collecting active radicals and increasing the tolerance of plants to abiotic stresses including salinity, drought and senescence. Plantago ovata Forssk is an annual herbal plant belonging to the Plantaginaceae family. So, among 28 species from Plantago genus, this species aspect economical is commercial source of mucilage. In recent years, according to reorganization plan for cultivation of medicinal plants in country, this crop has been recommended aspect 10 priority species of medicinal plants. Therefore, the purpose of this study was to evaluate the effect of foliar application of salicylic acid and spermine on some quantitative and qualitative characteristics of isabgol in water deficit conditions.

    Materials and methods

    The study was conducted as a split plot factorial experiment based on a randomized complete block design with 18 treatments and three replications in research field of the Gonbad Kavous University, Golestan Province, Iran in 2016. In this experiment, the treatment of irrigation included (non-stress: control), irrigation cutoff at flowering stage and irrigation cutoff at seed filling stage was the main-plot and factorial of salicylic acid (zero, 0.4 and 0.8 mM), plus spermine spraying (zero and 0.02 mM) were as a sub-plot. Foliar application of salicylic acid and spermine at budding (inflorescence production), flowering and seed filling stages were applied.

    Results and discussion

    Analysis of variance of data showed that in most of the characteristics, the combined effects of irrigation cutoff, salicylic acid and spermine, were significant at 1 or 5 percentage confidence levels. According to the results of the maximum grain and biological yield were found in the combined treatments of 0.8 mM salicylic acid spraying at irrigation interruptions at grain filling stage about 540.8 kg/ha-1 and 2795 kg/ha-1 respectively. The maximum amount of grain mucilage (19.7%) and swelling rate per gram mucilage (105.7 mg.l-1) were obtained in the treatment of 0.4 mM salicylic acid and 0.02 mM spermine in the absence of tension. According to the results, the foliar application of salicylic acid and spermine in cutoff irrigation conditions at flowering and seed filling stages significantly loss prevented more studied characteristics. It is concluded that the effective role of salicylic acid and spermine in osmotic regulation, membrane stability and elimination of active cell radicals could increase the tolerance of isabgol herb in water stress conditions.

    Conclusion

    According to the findings of this experiment and the research done on other plants, it was concluded that the leaf foliar application of medicinal plants with phenolic and polyamines compounds such as salicylic acid and spermine with suitable concentrations can be considered as an effective step to reduce the adverse effects of water stress and finally increase the qualitative and quantitative characteristics of plant.

    Keywords: isabgol, Mucilage, polyamines compounds, seed swelling factor, Water deficit
  • Hadis Hasanvand *, Seyedata Siadat, Abdolmehdi Bakhshandeh, MohammadReza Moradi Telavat, Adel Poshtdar Pages 519-531
    Introduction

    Borage (Borago officinalis L.) is an annual plant and belongs to the Boraginasea family, that afford curative properties. This plant has deep roots and can absorb soil, water and nutrients from the depths of the soil, and is therefore somewhat resistant to drought. Increasing people's tendency toward medicinal plants to treat diseases has conduct to and essential the cultivation of medicinal plants globally and in Iran. Water deficit stress is one of the most important non- biological stresses that reduces water absorption by root system. Water deficit is considered as the most important limiting factor for non-living plant growth and yield that, in addition to a negative effect on yield, causes exacerbates other stresses, in particular the stress of the deficiency of nutrients in the plant. Drought stress is one of the most important limiting factors yield in the world. Today, phenolic compounds and plant growth regulator has been proposed, to reduce the negative effects of stress. Thus, this experiment carried out in order to Effects of salicylic acid on yield and nutrient uptake borage (Borago officinalis L.) under interrupting irrigation conditions.

    Materials and methods

    A field study was conducted as a split plot arrengement based on randomized complete blocks design (RCB) with four replications at farm at experimental field of Khouzestan Agriculture Science and Natural Resources University, Iran during 2017-2018 cropping season. Three interrupting irrigation (stress at stemming stage, stress at flowering stage, stress at seed fill stage and control) as main plat and four application of salicylic acid including of 0, 69, 138 and 207 mg.L-1 as sub plots comprised experimental treatment. With reach each of these stages, from stem emergence to flowering initiation, from flowering initiation to seed fill interrupting irrigation and from seed fill initiation to beginning seed harvesting interrupting irrigation was carried out. This continued until the end of the physiological stages. Salicylic acid application was carried out during two stages during vegetative period (stem emergence and flowering initiation) simultaneously with applying moisture stress treatment. After applying the respective treatments, traits were measured at full flowering stage. Grain yield, oil percentages, ash contents of flower and leaf, nutrients of nitrogen, phosphorus, potassium, and sodium in two parts of the flower and leaf of Borage were measured. Analysis of variance and comparison of means was performed by SAS software and test LSD, 5% level probability .Respectively.

    Results and discussion

    The result of analysis of variance showed that interrupting irrigation and salicylic acid had significant effect on grain yield, oil percentages, ash contents of flower and leaf ash and nutrients of nitrogen, phosphorus, potassium, and sodium in two parts of the flower and leaf. Also interaction effect of interrupting irrigation and salicylic acid on flower ash, potassium flowers, and leaf, phosphorus and sodium flowers was significant. Mean comparison test showed that with interrupting irrigation in stemming and flowering stages, only the concentration of sodium and potassium elements and oil percentages increased significantly. Maximum grain yield in the control treatment was 633.43 kg. ha-1. Foliar application with 207 mg.L-1 salicylic acid increased 50% grain yield. Salicylic acid increased all the traits studied, other than sodium. Consumption of 138 mg.L-1 salicylic acid in interrupting irrigation condition increased 36% of flower ash and 38% of leaf phosphorus, due to non-consumption of salicylic acid and drought stress. The highest amount of potassium of flower and leaf were obtained by application 138 and 207 mg.L-1 salicylic acid in interrupting irrigation stress at flowering stage and maximum flowering sodium without application salicylic acid with interrupting irrigation in this stage.

    Conclusion

    The results suggested salicylic acid application in borage can increase uptake of macro nutrients required for plant growth and reduce the negative effects of drought stress damage.

    Keywords: Ash contents, Borago officinalis, nitrogen, Potassium, Sodium, Water deficit
  • Sarah Khajehhosseini, Farzad Fanoodi *, Sayed Ali Tabatabaee, Rostam Yazdani Biouki, Jafar Masoud Sinaki Pages 533-546
    Introduction

    Hyssop (Hyssopus officinalis L.) belongs to the family of Lamiaceae. woody, perennial, shrubs with short, four-stalks, with a height of 50 to 70 centimeters. Its small and reciprocal leaves, the sharp, perfect, very aromatic, and its beautiful flowers, dark blue to purple, white. This herb has a powerful, cough- Soothing, expectorant effect, more or less diuretic and stomach tonic. Drought stress, while decreasing green growth and yield, causes changes in antioxidant activity in this plant. In nature, different environmental stresses threaten the survival, yield and growth of plants. Drought stress is one of the most important environmental stresses limiting the production of plants around the world, especially in arid and semi-arid regions. Drought stress generally destroys and breaks down chloroplates and decreases chlorophyll content and decreases the amount of enzymes activity in the Calvin cycle during photosynthesis and ultimately reduces the growth and yield of the crop. The accumulation of compatible solutes is one of the effective mechanisms for modulating the stresses of dehydration or salinity. This regulation is performed by the production of more organic materials such as protein, soluble sugars, and amino acids such as glycine, proline, alanine and valine in the air and root organs. Glycine is one of the important amino acids in the environmental stresses and chemical formula is NH2-CH2-COOH. This research were investigate the effects of foliar application of glycine amino acid and its application time on growth and yield and antioxidant compounds of Hyssop under different irrigation conditions.

    Materials and methods

    The experiment was conducted as split plot factorial in a randomized complete block design with three replications of Yazd agricultural and natural resources research farm in 2016-2017. Irrigation at 25, 50, 75% of the available soil water from the soil, order to control, medium stress, severe stress as the main factor and foliar application treatments in two levels of distilled water (control) and glycine amino acid (2.5 per thousand) and two levels of foliar application (vegetative and just flowering, flowering) were considered as subplots. The measured traits included plant height, lateral branch number, leaf number, fresh and dry weight yield, total phenolic compounds flavonoid and anthocyanin levels. SAS software was used to analyze the data. Mean comparison was performed by LSD at the probability level of 5%.

    Results and discussion

    Different irrigation treatments reduced the number of lateral branches, number of leaf, fresh and dry weight yields, total phenol, but the anthocyanin content increased. No significant differences were observed between foliar application time treatments. Interaction effects showed that the combination of control irrigation and foliar application of glycine increased the height and number of lateral branches. Also this material in combination with irrigation mild and severe stress treatments levels increased leaf number, fresh and dry weight yield of plant compared to control.

    Conclusion

    The results of this present study indicated that the external application of glycine amino acid in addition to reducing the damage caused by water stress in the plant, also has increased the plant's ability to improve grow and enhance yield.

    Keywords: Compatible solutions, Foliar application, Free radicals. Osmotic modification
  • Babak Mirshekarnezhad, Farzad Paknejad *, Ebrahim Amiri, MohammadReza Ardakani, MohammadNabi Ilkaee Pages 547-557
    Introduction

    In many parts of the world where agriculture is important, crops usually encounter a large variation in water supply during their growing seasons. Thus, water deficit is a major constraint to crop production, even in humid environments (Soltani and Sinclair, 2012). In the context of improving water use efficiency (WUE), there is growing interest in deficit irrigation which involves applying stress levels to plants that have minimal effects on yields in order to optimize yields per unit of water used as well as crop returns increment (Rodrigues and Pereira 2009). One of the planting date goals is to detect the time after which crops could be able to keep immune even versus adverse climatic conditions Berzsenyi & Lap (2005). Arid and Semi-arid climate in the most parts of Iran with limited water resources highlights applying adaptive methods as well as new approaches to support crop producers in selecting proper varieties, accurate planting date and using water in an optimum way to maximize productivity and returns.‌

    Material and methods

    In order to probe those of agronomic traits contributing to final yield and detecting susceptible growth stages of corn to water stress a field study took place in research farm of College of Agriculture and Natural Resources, University of Tehran. Considering irrigation management and planting date as adaptive techniques and due to the rating of relative maturity (RM) of maize hybrids, (S.C. 704) selected as late-maturing hybrid in this experiment. The experiment implemented in split-plot template based on randomized complete block design with three replicates in 2015 and 2016 cropping seasons. The experimental treatments consist of three planting dates, (PD1: 21st April, PD2: 11th May and PD3: 31st May) assigned to main plots and four irrigation treatments, (100%ETc, 80%ETc, 60%ETc and 40%ETc) of the estimated evapotranspiration (ET) placed in sub plots.

    Results and discussion

    The lower of grain yield (4150.30 and 3589.60 kg ha-1) and less total biomass (14354.60 and 13563.90 kg ha-1) resulted in stress treatment of 40%ETc respectively in 2015 and 2016. The highest values of irrigation water use efficiency based either on grain yield (1.39 and 1.20) or total biomass (4.79 and 4.53) were culminated in 40%ETc treatment for the period of two years respectively. It seems that in the presence of deficit irrigation plant capability in converting per unit of water to biomass will be improved through transpiration. Our results corroborated by those of Chaichi et al. (2015) who issued stepwise reduction for ear yield, total dry matter and grain yield in stress treatment as ETc decreased. Also lower rates of harvest index (28.76 and 26.34%) also recorded at 40%ETc treatment in both years respectively. Similar results revealed by Farré and Faci (2006) who found that HI decreased markedly with increasing water stress. The lower values of grain yield and total biomass obtained at the later-planted corns due to coincidence of pollination phase with the higher levels of temperature and evapotranspiration in mid and late planting dates (PD2 and PD3).

    Conclusion

    In fact crops planted earlier in the season tend to develop more gradually, under cooler temperatures with enough accessibility to more abundant soil water supplies and nitrogen availability. In this experiment, water stress during pollination time affected corns under common planting date (PD2). However, as the tail-end maturation of later-planted corns (PD3) approach cooler temperatures of early autumn, due to rapid loss of leaves there is less time for them to compensate yield losses and generally results in lower overall productivity. To help farmers for applying water more efficiently, they must pay attention to align planting date and applied hybrid with local agro-ecological endowments to avoid of irrigations that are surplus to requirements.

    Keywords: Biomass, Evapotranspiration, Maize Pollination stage, Water deficit stress
  • Seyed Ali Tabatabaei, Sepideh Nikoumaram, Omid Ansari * Pages 559-570
    Introduction

    Drought stress is one of the most important environmental factors to reduce the growth, yield and yield components of many crops, especially in arid and semi-arid regions of the world.Temperature is very important for seed germination. There for it can be said, and water potential are two primary environmental regulators of seed germination. Quantification of germination response to water potential at different temperature is possible using hydro time model. In this study, with using hydro time model quantification of Brassica napus L. germination response to water potential and temperature.

    Material and methods

    In this study germination response of Brassica napus L. to water potential at different temperature were studied. Experiments were conducted in 2017 on Brassica napus L. (Okapi) at the seed laboratory of Yazd Agricultural and Natural Resources and Education Center, AREEO, Yazd, Iran. Treatments included drought levels (0, -0.2, -0.4, -0.6 and -0.8 MPa) in temperatures of 10, 15, 20, 25 and 30 °C. The response of cumulative germination seeds to different potentials at different temperature was quantified using normal function. All data were analyzed by SAS ver 9.2. The hydro time model was fitted to cumulative germination. Goodness of fit of the hydro time models to all data was checked by constructing plots of the coefficient of determination (R2), the relationship between the observed and the predicted germination percentage and base water potential.

    Results

    Results indicated that germination percentage increased with increasing temperature to 25 °C in all water potentials, while germination percentage and germination rate reduced as a result of water potential increment. The highest germination percentage (94 %) was obtained from control conditions at 20 and 25 °C. The minimum germination percentage (zero) was attained at 30 °C and -0.8 Mpa. Results indicated that, The hydro time constant (θH), base water potential, standard deviation of base water potential in population and the coefficient of determination (R2) for 10 °C were 81.34 Mpa h, -0.75 Mpa, 0.41 and 0.89, for 15 °C were 52.17 Mpa h, -0.82 Mpa, 0.47 and 0.70, for 20 °C were 28.71 Mpa h, -0.91 Mpa, 0.44 and 0.71, for 25 °C were 17.54 Mpa h, -0.81 Mpa, 0.42 and 0.73 and for 30 °C were 11.24 Mpa h, -0.52 Mpa, 0.35 and 0.82, respectively. The hydro time constant (θH) declined significantly with increasing temperatures, so that the minimum hydro time constant (11.24 MPa h) was attained at 30 °C. The increment of temperature resulted in significant reduction of base water potential, and the highest base water potential (-0.91 MPa) was obtained at 20 °C, and the minimum base water potential (-0.52 MPa) was attained at 30 °C. The minimum standard deviation of base water potential in population (0.35) was obtained at 30 °C, using hydro time model for quantitation of Brassica napus L.

    Conclusion

    Germination response to water potential at different temperatures, led to acceptable results. Utilizing the output of hydro time model at different temperatures can be useful in prediction of germination percentage of Brassica napus L. in different water potential.

    Keywords: Germination percentage, Germination rate, Normal function, Temperature
  • Seyed Hamidreza Hashemi Petroudi *, Ghorbanali Nematzadeh, Samira Mohammadi, Markus Kuhlmann Pages 571-581
    Introduction

    Heat shock proteins (HSPs) are one of the main stress-responsive genes in plants that highly express in response to variable environmental stresses. Expression of HSP genes is primarily regulated by attaching heat shock transcription factors (HSFs) to binding sites at their promoter region. HSFs and their coding genes have been widely characterized in several plant species, but so far no report is available on the structure, organization, phylogenetic relationships and expression profile of these genes in halophyte species. Identification and characterization of gene family members properties in stress tolerant plant can be useful to understanding their molecular function and biological processes. The present study aimed to identify the HSF transcription factor gene families in halophyte plant Aeluropus littoralis.

    Materials and methods

    The protein sequences of Arabidopsis thaliana HSF gene families were blasted against Aeluropus littoralis genomic sequences by local TblastN tools. After removing repetitive sequences, all sequences were verified by BlastP. In order to identification, annotation and analysis of domain architectures, the identified proteins were analyzed in different protein domain databases including Pfam 32.0, PROSITE and InterProScan. Similarity clustering based on motifs patterns were done by SALAD tool in all AlHSFs. The structure of exon and intron was generated by comparing the predicted CDS against genomic sequences of AlHSFs in gene structure display server (GSDS). The expression pattern analysis of AlHSFs genes was carried in leaf and root tissues under salinity stress and recovery conditions by transcriptome analysis.

    Results and discussion

    In total, 11 non-redundant HSF genes encoding HSF domain-containing proteins were identified in A. littoralis genomes. Aeluropus HSF genes were named based on their identity to Arabidopsis AtHSF homologous proteins. All 11 AlHSFs were divided into three classes (A, B, and C), based on homology with Arabidopsis. Seven genes belonging to the HSFA class and three genes belonging to the HSFB class, and finally HSFC class like Arabidopsis had one gene. The gene structure analysis showed that AlHSF gene family member had distinct gene features, such as the composition and position of exons, introns, and conserved elements. The most AlHSF genes had two exons and one intron, while two genes (AlHSFA6B.1 and AlHSFA1B) contained three exons and two introns. AlHSFA6B.3 had six exons and five introns while AlHSFA6B.2 with one exon was intronless. Based on SALAd tool, 13 conserved motifs were identified from 11 AlHSFs. Motifs of 1, 2, 3, 4 and 5 were presented in most AlHSF proteins, except for AlHSFA6B.2 which lacked the motif 4 and 5. Motif 2 was also absent only in AlHSFA6B.2 and AlHSFB4. Removal of these motifs may have occurred during gene duplication in the evolutionary process of this family, resulting in shorter coding regions. Also, the results revealed that some motifs were present in specific AlHSF proteins. For example, motif 10 only existed in AlHSFA6B.1 and AlHSFB1. Motif 12 was only present in AlHSFA6B.1 and AlHSFA1B. The phylogenetic tree divided the proteins into three groups based on the existence and distribution of different motifs. The expression pattern of AlHSFs genes in leaf and root tissues under salinity and recovery conditions showed that AlHSFA6B.3 gene was not expressed, indicating that this gene was silent in these tissues under corresponding stress. AlHSFB2A gene had the highest expression level (1.11) in leaf tissue under salinity stress. After that, AlHSFA6B.1 gene with expression levels of 0.96 and 0.87 was expressed more in leaf tissue under salinity stress and recovery, respectively. The least expression level was observed in AlHSFC1 and AlHSFA3 genes, respectively, which was four times less than the control. AlHSFC1 gene showed a significant expression decrease in the recovery conditions after a little expression increase in leaf tissue under salinity stress. Significant expression decrease of AlHSFA3 gene was observed in root tissue under salinity stress which indicates its role as a negative regulator in response to salt stress.

    Conclusion

    Different expression patterns of AlHSF family member suggest distinct modes of positive and negative gene expression regulation. These may also be related to their different molecular functions as well as diverse regulatory mechanisms involved in controlling the activation of these genes. The findings of this study reveal the functional characteristics of the AlHSF genes and provide a foundation for future functional research regarding their biological roles in plant tolerance to stress.

    Keywords: Gene structure, Heat shock proteins, Protein motifs analysis, Transcriptomics analysis
  • Fariba Morsali Aghajari, Reza Darvishzadeh *, Gholamhosein Gholami Pages 583-600
    Introduction

    Salinity is one of the main abiotic stresses, especially in arid and semi-arid conditions, which affects plant growth and thereby reduces seed yield.

    Materials and methods

    In the first part of this study, the morphological changes in 98 recombinant inbred lines population of oilseed sunflower derived from the cross of PAC2 × RHA266 were investigated in a complete block design with 3 replications under normal and 6 dS/m of salinity stress conditions. In both conditions, after flowering stage the characteristics including, grain yield per plant, 100 seeds weight, leaf number, stem diameter, plant height, capitol diameter, leaf length, leaf width, petiole length, capitol dried weight, date to flowering were measured. The relationship between grain yield and other morphological characteristics were investigated by simple correlation and stepwise regression analyses. Cluster analysis was used for grouping the genotypes based on all studied morphological characteristics in each one of normal and salinity conditions. Based on the results of the first part of work, two salt tolerant and sensitive lines (respectively C86 and C64 lines) were selected and planted at different salinity levels (0, 2, 4, 6 and 8 dS/m) conditions and their protein electrophoresis patterns were investigated using SDS-PAGE.

    Results and discussion

    Based on the results of analysis of variance, salinity × genotype interaction effect was significant on all studied traits except for plant height, which indicated that the reaction of lines was different depending on different environmental conditions. Comparison of mean of lines in normal and salt stressed conditions indicated that the average of lines under salinity stress conditions decreased compared to normal one. However, the percentage of reduction is different depending on the traits. Heritability of traits varied between 0.07 for width of leaf to 0.50 for leaf number and day to flowering in normal conditions and in salinity stress conditions it varied between 0.09 for petiole length to 0.48 for weight 100 seeds and day to flowering. Based on stepwise regression analysis, the head diameter and 100 seeds weight were entered in the model and explained some part of yield variation in both salinity and normal conditions. So, selecting for these traits will improve grain yield in both conditions. In grouping of lines by using the minimum variance method (Ward method), all genotypes were grouped in 3 clusters in each of the environmental conditions. Under normal conditions, 49, 29 and 12 genotypes were grouped in the first, second and third clusters, respectively, and under salinity stress conditions, 42, 37 and 14 genotypes were placed in the corresponding groups. Based on the results of molecular experiment, different electrophoretic patterns for C86 and C64 lines were observed at different levels of salt stress, indicating a different reaction of lines to salt stress.

    Conclusions

    The highest coefficient of phenotypic variations was observed for grain yield, petiole length, leaf width, 100 seeds weight and head dried weight in both normal and salinity stress conditions which indicated their determinant roles in the development of phenotypic variation. In this study, traits such as capitul diameter and 100 seed weight due to high genetic variation, positive correlation and high direct effect on grain yield and moderate heritability, are suggested as desirable traits for selection of promising genotypes. In the second part of the study, based on the results, different electrophoretic patterns for C86 and C64 lines were observed at different levels of salt stress, indicating a different response of the genotypes to salinity stress.

    Keywords: Heritability, Oilseed sunflower, Protein electrophoresis, salinity stress, Stepwise regression
  • Somayyeh Sanchouli, Mahmoud Ghorbanzadeh Neghab, Hossein Sabouri *, Mohammad Zare Mehrjerdi Pages 601-611
    Introduction

    Rice (Oryza sativa L.) is a major source of food and energy for more than 2.7 billion people on a daily basis and is planted on approximately one-tenth of the earth's arable land. Rice is one of the most important cereal. Salinity is the second most problem next to drought, in rice growing areas of the world. Soil salinity is a abiotic stress in crop productivity worldwide. The aim of the present study is to identify QTLs related to salt tolerance by using an Iranian rice population and Comparison of different QTL mapping methods.

    Materials and methods

    A F8 RILs population, derived from a cross between a salt tolerance Ahlemi Tarom (ATM) and salt sensitive Neda (NAD) which were used in this study. The early crosss and segregated generations in the University of Gonbad Kavous were developed. The genetic material involved 96 lines were used to evaluate the salt tolerance. This experiment was conducted at the faculty of agriculture, university of Gonbad-Kavos, in 2016 as hydroponics. The seeds were placed 50 C for 3 d to break dormancy, and then germinated at 25 C for 72 hours. Finally, the germinated seeds were sown in holes of the Styrofoam board with a nylon net bottom, which floated on water for 3 d, and after were transferred to float on Yoshida's nutrient solution for 11 d. two week after sowing, the seedling were transferred to nutrient solution with electrical conductivity 6 dSm-1 for 7 days, then NaCl concentration was increased to 12 dSm-1 for further 7 days. This experiment was conducted in a controlled condition with 16-h photoperiod, temperature of 29/21 C and minimum relative humidity of 70%. The culture solution was renewed weekly and the PH was adjusted daily to 5.5 by adding either NaOH or HCL. Chlorophyll content was measured using a SPAD device. 40 SSR primer pairs, 16 ISSR markers (76 alleles), two IRAP markers (7 alleles) and one iPBS marker (3 alleles) were appropriately distributed on 12 rice chromosomes. Finally, The genes controlling the chlorophyll content located using different QTL mapping methods in clouding SIM-MEL، SIM، CIM، MIM، PMLE، ICIM and STSIM. These methods detected different QTL.

    Results and discussion

    In CIM-MLE method, five QTL were detected on chromosomes 3, 5, 6, 7 and 8 in normal condition, and three QTL were detected on chromosome 2 and 6 in salt stress condition. In SIM method, three QTL were identified on chromosomes 2, 3 and 8 in normal condition, and five QTL were identified on chromosomes 4, 6, 7 and 10, in salt stress conditions. In CIM method, three QTL were detected on chromosomes 2, 3 and 8, these QTLs justifying 13-23% of the phenotypic change of trait, in normal condition, but under salt stress condition, six QTL were detected on chromosomes 1, 2, 6 and 7. qCHLN-3, qCHLN-5 and qCHLN-6 were detected by MIM method in normal condition and qCHL-6a and qCHL-6b were detected on chromosome 6 in salt stress condition. Six QTL were detected by PMLE method in normal condition and two QTL detected on chromosomes 6 and 9 in salt stress condition. In ICIM method, three QTL were identified on chromosomes 2, 3 and 8 in normal condition, in salt stress condition were detected five QTL on chromosomes 4, 6, 7 and 10. qCHLN-3, qCHLN-6 and qCHLN-7 were detected by STSIM method in normal condition, andqCHL-6on chromosome 6 and has a LOD of 3.187 and an additive effect of -0.079.

    Conclusions

    ICIM, CIM and SIM has most closely in genetic location in normal and salt stress conditions. qCHL-6 was identified in six location method at 52 cM position in chromosome 6. qCHLM-3 and qCHLN-8 were detected in CIM, CIM and SIM on chromosomes 3 and 8 and explaining 18-22% of phenotypic variance chlorophyll content in normal condition. CIM, ICIM and SIM method were detected QTLs on chromosomes 6 and 7. Among the methods used, the CIM has the least error in estimating the original QTL effect and it can be done at any point in the genome that is covered by markers and the performance of the markers is higher in this method. Therefore, the effectiveness of using the markers introduced in this method will be higher. The results of this study can identify the better genotypes in term of chlorophyll content for marker selection programs after validation of QTLs.

    Keywords: hydroponic cultivation, QTL, quantitative trait, Rice
  • Atefeh Rahmani-Kamrodi, Saeid Navabpour *, Ahad Yamchi, AliAsghar Nasrolahnejad Ghomi Pages 613-623

    The purpose of this experiment was study on genetic variation of wheat mutant lines (T-67-60 and T-65-7-1) and its parent (Tabasi cultivar) using RAPD molecular marker and also compare some biochemical parameters of salinity tolerance between the mutant lines and the parent in response to salt stress in the seedling stage.In this study, two mutant lines of wheat (T-67-60 and T-65-7-1) with its parent (Tabasi cultivar), cultured in the Yoshida hydroponics at 30 °C and lighting condition (16 hours of light). Then salinity stress induced on wheat seedling at electrical conductivity 6 dS m-1 and leaf samples were collected for DNA extraction and evaluation of biochemical parameters (proline, protein and chlorophyll content).The pattern of RAPD marker showed more similarity of line mutant T-67-60 with parent (Tabasi cultivar).The results of biochemical parameters showed that mutant lines (T-67-60 and T-65-7-1) were higher tolerance than parent (Tabasi cultivar) under salinity stress.Variability of mutations induced by gamma radiation in wheat revealed and verified with molecular RAPD primers. In addition, differences in biochemical characteristics under salinity condition in the mutant lines (T-67-60 and T-65-7-1) and the parent (Tabasi) implies genetic variation for these traits.

    Keywords: Morphology, Mutant wheat, Physiology, RAPD marker, salinity stress
  • Ahmad Aien *, Amir Jalali Pages 625-635
    Introduction

    The sever heat stress at the end of growing season in potato winter cultivation, always has been one of the major challenges in warm areas of Iran. Heat stress reduces the yield, quality and shelf life of the potato tubers by increasing the amount of respiration and changes at the balance of sugars and starch in the tubers. One of the suitable strategies to reduce the impacts of heat stress on potatoes is the use of calcium, especially calcium nitrate, which has been investigated in this experiment.

    Materials and methods

    This Study conducted as split-split plot experiment based on randomized complete block design with three replications in South Kerman Agricultural Research and Education Center during 2013-2014. The main factor was sowing date: suitable sowing time (31th Dec.) and delay sowing (4th Feb.) and three potato cultivars (Sante, Satina and Milva) were kept in sub-plot. Four calcium treatments (no calcium application, spraying 2500 ppm calcium nitrate in two stages (tuberization and 20 days after tuberization) and spraying 2500 ppm calcium nitrate in three stages (tuberization, 20 and 40 days after tuberization), and soil application of 75 kg/ha calcium nitrate in two stages (tuberizatin and bulking stages) were in sub-sub plots. The measured characteristics included the amount of calcium in the leaf and tuber, the amount of reducing sugars, total sugars and starch in tuber and the rate of rottenness of tubers after 60 days storage.

    Results and discussion

    The results showed that Sante and Satina cultivars had the highest amount of calcium in the tuber, and Milva cultivar had the lowest calcium content. The heat stress at the end of the growing season in delay sowing increased the amount of total and reducing sugars of tubers. The application of calcium especially its soil application, in both delay sowing and suitable sowing time reduced the amount of total and reducing sugars and increased starch and calcium content of the tubers and calcium content of leaves. The application of calcium nitrate in delay sowing reduced the amount of total and reducing sugars as compared to control (non-application of calcium in delay sowing) by 19.4 and 21.9 % respectively, which indicating the impact of calcium application under heat stress conditions on decreasing the tuber sugars and improving quality of tubers. Soil application of calcium in delay sowing reduced the amount of reducing sugars compared to foliar application. Interaction of soil application of calcium nitrate in suitable sowing time (non-stress) and delay sowing (heat stress) had the highest starch and calcium content, respectively. The interaction of sowing date and calcium application on the rate of rottenness of tubers after 60 days storage indicates that the highest levels of rottenness related to the no calcium application in delay sowing, which can be due to impact of higher temperature (heat stress) at the end of the growing season. The application of calcium reduced the rate of rottenness of tubers, so that the reduction in the rate of rottenness of tuber in the soil application of calcium nitrate in delay sowing compared to control (non-application of calcium in delay sowing) was 30.5 percent. There was significant positive correlation between rottenness of tuber and tuber sugars, and significant negative correlation between rottenness with starch and calcium of tuber. The mention results indicate the role of calcium application in improving the shelf life and storage of potato tubers.

    Conclusions

    The application of calcium in delay sowing (under heat stress) reduced the total and reducing sugars and increased starch and calcium content of the tubers compared to control. Probably due to the effect of calcium on reducing the amount of tuber sugars, as well as its role in strengthening the cell wall of the tuber tissue, the rate of rottenness of tuber decreased. Therefore, the application of calcium nitrate especially its soil application by 75 kg/ha, in order to increasing the shelf life and storage of potato tubers, is recommended in delayed planting in warm southern areas of the Iran.

    Keywords: Calcium nitrate, Heat Stress, Reducing sugars, Spraying, Soil application
  • Alireza Borjian Boroujeni*, Seyed Ataollah Siadat, Abdolmahdi Bakhshandeh, Khalil Alami Saeid, Mohamadreza Jalal Kamali Pages 637-651
    Introduction

    Heat stress during reproductive development is the main limitation in the production of wheat in most of the wheat fields in the world. It is important to recognize the physiological and molecular mechanisms associated with heat tolerance and the detection of screening methods in improving plants to tolerate heat. In Iran data from the effect of short-term heat wave on yield and physiological mechanisms do not exist under field conditions. The objective of this study was to determine the effects of short-term heat stress near flowering and early grain filling on grain yield and physiological parameters.

    Materials and methods

    This research was conducted at research farm of Khuzestan Agricultural Sciences and Natural Resources University, located 35 km northeast of Ahwaz, in 2014. Four wheat genotypes (Chamran. Maroon, Arvand and Atrak) were exposed to heat stress (maximum 35 °C) for a three-day in the field with a portable heat chamber at two different stages, near flowering (H1) and early grain set (H2). Chlorophyll content was measured using manual chlorophyll. Stomatal conductance was performed from the top three leaves of selected plants. Chlorophyll concentration was calculated using the Arnon method (1949). Cell membrane thermostability (CMTS) were calculated using the following equation: CMTS (%) = [1- (EC1 / EC2)] × 100where EC1 and EC2 are the primary electrical conductivity (before the autoclave) and the secondary (after the autoclave), respectively. Proline was maesured using Bates method (1973). Ascorbate peroxidase (APX) activity was measured using Nakano and Asada method (1987). Catalase (CAT) activity was measured using Aebi method (1983), peroxidase activity (POX) was measured using Chance and Maehly method (1955), Superoxide dismutase was measured using Biochamp and Fridovich method (1971). Malon de aldehyde (MDA) was measured using Hess and Packer (1969). All calculations were performed using the SAS-9.4 statistical software. Factor analysis was done by using principal component analysis and Varimax rotation on the temporary factor.

    Results and discussion

    The results of analysis of variance showed that there were significant differences between heat stress levels and the traits of genotypes. Short-term heat stress (H1 or H2) decreased the average grain yield of Chamran, Maroon, Arvand and Atrak genotypes by 19.6, 18.6, 17.8 and 11.2 percent. Heat stress significantly caused to reduce water potential, chlorophyll fluorescence, leaf relative water content and cell membrane thermostability whereas stomatal conductance, chlorophyll destruction rate and proline content increased. Although there was no significant effect of short term heat stress on total chlorophyll concentration in this experiment, there was a negative correlation between grain yield and total chlorophyll concentration (r = -0.67 in H1 and r = -0.77 in H2). The activity of catalase, peroxidase and superoxide dismutase increased significantly in response to H1 or H2. The results of the factor analysis showed that four factors explained 86.7% and three factors explained 86.4% the variance among varieties in H1 and H2, respectively. Atrek, Chamran and Arvand varieties tolerated heat stress than Maroon variety by more photosynthesis persistency, higher metabolite content and more enzyme defense mechanism. It could be argued that cultivars with slower rate of leaf senescence after heat exposure and more enzymatic protection could be more tolerant to heat stress.

    Keywords: Antioxidant enzymes, Factor analysis, Heat, Photosynthesis
  • Hoorie Najafi, Saeed Navabpour *, Khalil Zainli Nezhad Pages 653-665
    Introduction

    Mercury, as a heavy metal element, plays an important role in contaminating the environment and causing toxicity and stress in living organisms. . Heavy metals are defined as metals having an atomic number greater than 20 densities greater than 5 grams per cubic centimeter.Non-toxic stresses, including heavy metals, cause much damage to wheat. The industrialization of societies is releasing many toxic compounds on the biosphere. Among heavy metals, mercury is considered to be the most toxic metal in the environment. This metal is considered as the major environmental pollutant. Its toxicity is a big problem for ecological, evolutionary, nutritional and environmental reasons. In fact, heavy metals do not excrete the body after entering the body and accumulate in the tissues of the body. Despite the contamination of resources used in heavy metals, while reducing the quantity and quality of agricultural products, sustainable production and human health are also at risk. The same causes many diseases and complications in the body, the pollution of the environment with heavy elements will transfer them to crops, which is now spreading as a global problem.Mercury ions produce oxidative stress that produces reactive oxygen species in plants. This pro cess damages the structure of the membranes and disrupts the cytoplasm of the cell. To reduce and eliminate various active oxygen species and avoid oxidative damage in plants, the activity of antioxidant enzymes such as catalase increases. One of the other mechanisms of coping with heavy metal stresses in living cultures is the production of intracellular, rich in cysteine amino acids such as metallothionein. The high number and special makeup of cysteine amino acids in these proteins has made it possible to connect them to metals.

    Materials and methods

    A split plot experiment was conducted in a completely randomized design with hydroponic culture. The treatments consisted of chloride ivy with concentrations (0, control, 5, 10 and 15 μm) as the main factor and bread wheat genotypes (morvared, gonbad and N9108) as a sub factor.

    Results and discussion

    Results showed that the expression of catalase and metallothionein gene was increased in morvared and N9108 genotypes by mercury chloride and the highest expression of these genes was obtained by treatment with 15 mM mercuric chloride (9.2 and 2.7 times more than control) Was. In Gonbad cultivar, the amount of gene expression was increased by treatment with mercury chloride compared to control, but this increase was lower than the other two genotypes. By increasing the concentration of mercury chloride, there was a significant decrease in the chlorophyll content of different genotypes, as well as chloride ivy significantly increased the oxidative cell index in the treated seedlings compared with the control It can be concluded that the morvared cultivar and the promising line of N9108 under heavy metal stress showed a better response than the gonbad. Used to deal with heavy metal stresses. According to the results of this experiment, it seems that the antioxidant defense system plays an important role in the defense strategy of the wheat plant against the tension of mercury metal and this defense system is induced and activated at the transcriptional level to help the plant.

    Keywords: Catalase, Hydroponic culture, Mercury Chloride, Wheat, Metallothionein, Seedling stage