فهرست مطالب

  • سال سیزدهم شماره 1 (بهار 1399)
  • تاریخ انتشار: 1399/01/10
  • تعداد عناوین: 25
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  • فرزانه فخیمی، علیرضا مطلبی آذر، فریبرز زارع نهندی، نعمت سخندان بشیر، غلامرضا گوهری* صفحات 1-8

    تنش شوری، یک تنش محیطی است که رشد و نمو گیاهان و تولید محصولات کشاورزی ازجمله سیب زمینی را در بیشتر نقاط جهان متاثر می سازد. بحران زیست محیطی دریاچه ارومیه و اثرات منفی آن بر زمین های کشاورزی اطراف این دریاچه به عنوان یک تهدید جدی برای تولید بسیاری از محصولات مهم و اقتصادی کشاورزی همچون سیب زمینی محسوب می شود. گلایسین بتائین در اکثر گیاهان به عنوان یک ماده غیر سمی باعث افزایش تحمل گیاهان به شرایط نامناسب تنش های شوری و خشکی می گردد. مطالعات زیادی در مورد چگونگی دخالت سالیسیلات ها در واکنش گیاهان به تنش های غیرزنده محیطی از قبیل تابش ماورای بنفش، خشکی، شوری و سرمازدگی انجام یافته است. در این تحقیق، تاثیر تنش شوری (کلرید سدیم) و تیمار اسید سالیسیلیک بر بیان ژن بتائین آلدهید دهیدروژناز (LOC102601322) به روش RT-PCR نیمه کمی در گیاهچه های سیب زمینی رقم اگریا در محیط کشت MS بررسی شد. برای این منظور، آزمایشی به صورت آزمایش فاکتوریل در قالب طرح کاملا تصادفی با سه تکرار و در هر تکرار با چهار ریز نمونه در آزمایشگاه کشت بافت گیاهی گروه علوم و مهندسی باغبانی دانشگاه تبریز به اجرا در آمد. عامل های آزمایش، شامل شوری (کلرید سدیم) در دو سطح (صفر و 70 میلی مول بر لیتر)، اسید سالیسیلیک در چهار سطح (صفر، 1، 10 و 100 میلی مول بر لیتر) بود. نتایج نشان داد که اثر تیمار کلرید سدیم بر میزان گلایسین بتائین معنی دار بود، بااین حال اثر متقابل شوری و اسید سالیسیلیک بر صفات بیوشیمیایی معنی دار نبود. نتایج مولکولی نشان داد که میزان بیان ژن بتائین آلدهید دهیدروژناز در تمام غلظت های بررسی شده اسید سالیسیلیک و تنش شوری نسبت به گیاه شاهد افزایش قابل توجهی نشان داد که حداکثر میزان بیان این ژن در غلظت 100 مول بر لیتر اسید سالیسیلیک مشاهده شد. همبستگی معنی داری بین بیان ژن بتائین آلدهید دهیدروژناز و میزان گلایسین بتائین مشاهده شد. چنین به نظر می رسد که کاربرد اسید سالسیلیک موجب کاهش اثرات منفی تنش شوری در گیاهچه های سیب زمینی در شرایط کشت درون شیشه ای می گردد.

    کلیدواژگان: بتائین آلدهید دهیدروژناز، تنش غیرزیستی، کشت درون شیشه ای، گلایسین بتائین، RT-PCR نیمه کمی
  • زبیده کهن پور، عاطفه صبوری*، ابراهیم هزارجریبی، علی اعلمی صفحات 9-26

    سویا (.Glycine max L) یکی از مهمترین دانه های روغنی می باشد. در مطالعه حاضر، تعداد 30 ژنوتیپ سویا متشکل از 27 لاین پیشرفته نسل F8 و سه رقم والدینی سحر، ویلیامز و کتول از لحاظ صفات مورفولوژیکی و عملکردی در دو محیط بدون تنش و تحت تنش کم آبی در منطقه ازبرم از توابع شهرستان سیاهکل واقع در استان گیلان طی سال 1395 ارزیابی شدند. این آزمایش در قالب طرح بلوک های کامل تصادفی با سه تکرار انجام گرفت. نتایج تجزیه واریانس مرکب نشان داد که برای تمام صفات به جز صفت طول غلاف، اختلاف بین ژنوتیپ ها و برهم کنش بین ژنوتیپ و محیط در سطح یک درصد معنی دار بودند که بیانگر وجود تنوع ژنتیکی بالا و واکنش متفاوت ژنوتیپ ها در دو محیط بدون تنش و تحت تنش کم آبی از لحاظ صفات مختلف بود. بر اساس تجزیه خوشه ای به روش حداقل واریانس Ward تحت شرایط بدون تنش، ژنوتیپ ها به سه گروه تفکیک شدند. گروه اول متشکل از پنج لاین پیشرفته کتول×ویلیامز(3123)، ویلیامز×کتول(4)، ویلیامز×همیلتون(2)، سحر×همیلتون(4)، گرگان3×ویلیامز(2) و رقم کتول بود که از لحاظ تمامی صفات، از جمله صفات عملکردی مانند تعداد و وزن غلاف ها، وزن کل دانه های بوته و وزن صددانه، میانگین بیشتری از سایر ژنوتیپ ها داشتند. در شرایط تنش کم آبی نیز ژنوتیپ ها در سه گروه قرار گرفتند که گروه سوم شامل چهار عضو متشکل لاین های سحر×کتول(4)، ویلیامز×همیلتون(1)، ویلیامز×K778(3) و ویلیامز×کتول(4) از لحاظ صفات مهم عملکردی، برتر از سایر ژنوتیپ ها عمل کردند. همچنین بر اساس نتایج تجزیه به مولفه های اصلی و بای پلات حاصل از دو مولفه نخست، لاین گرگان3×ویلیامز(2) در شرایط بدون تنش و لاین ویلیامز×کتول(4) در هر دو شرایط برتر از سایر لاین ها و ارقام والدینی عمل نمودند.

    کلیدواژگان: تجزیه به مولفه های اصلی، تجزیه خوشه ای، تنش خشکی، دانه روغنی
  • علیرضا رهی، حمید نجفی زرینی*، غلامعلی رنجبر، مهدی قاجار سپانلو صفحات 27-40

    به منظور شناسایی ژنوتیپ های متحمل به خشکی گیاه سویا آزمایشی گلخانه ای به صورت فاکتوریل در قالب طرح بلوک های کامل تصادفی با سه تکرار در سال 1396 در دماوند انجام شد. فاکتورهای مورد بررسی شامل 50 ژنوتیپ سویا و دو سطح آبیاری نرمال و قطع آبیاری در زمان غلاف دهی بود. نتایج تجزیه واریانس نشان داد که واکنش ژنوتیپ های سویا به شرایط تنش خشکی و بدون تنش متفاوت بود. ژنوتیپ های 2، 14، 21، 38 و 49درهر دو شرایط تنش خشکی و بدون تنش و ژنوتیپ های 25 و 14 فقط در شرایط تنش عملکرد بالایی را نشان دادند. برای تعیین مناسب ترین شاخص ها از همبستگی شاخص های تحمل به خشکی با عملکرد دانه ها در شرایط تنش و بدون تنش استفاده شد و بر این اساس از 17 شاخص 10 شاخص قابل اعتماد معین شد و ژنوتیپ های برتر این شاخص ها نیز مشخص گردید. ژنوتیپ برتر برای میانگین تولید شاخص بهره وری ، میانگین هندسی، میانگین هارمونیک و شاخص تحمل خشکی ژنوتیپ شماره 14بود و ژنوتیپ های 14 و 25 برای شاخص عملکرد، ژنوتیپ های25 و34 برای شاخص پایداری عملکرد، ژنوتیپ 25 برای شاخص مقاومت به خشکی و شاخص تولید غیر تنشی تنش و ژنوتیپ های 14 و 49 برای شاخص تحمل غیر زیستی و شاخص تحمل تنش تعدیل شده برتر بودند. کلیه شاخص های تحمل به خشکی در تجزیه به مولفه های اصلی وارد شدند و نتایج نشان داد که مولفه های اول و دوم در مجموع 99/97% واریانس کل را تبیین کردند. شاخص هایی که بالاتر بودن مقادیر آن ها نشانه متحمل بودن گیاه به خشکی می باشد، در مولفه اول و شاخص هایی که بیشتر بودن آن ها مبین حساسیت گیاه به خشکی می باشد در مولفه دوم قرار گرفتند. تجزیه کلاستر ژنوتیپ ها را به 8 گروه تقسیم نمود و ژنوتیپ های2، 14، 21، 23، 42 و 49 در یک گروه قرار داد این ژنوتیپ ها بر اساس میانگین در هر دو محیط عملکرد خوبی دارند.

    کلیدواژگان: آبیاری، تجزیه همبستگی، تنش غیر زیستی، عملکرد
  • فاطمه درویش نیا، محمدهادی پهلوانی*، خلیل زینلی نژاد، خسرو عزیزی صفحات 41-56

    این تحقیق به منظور بررسی شاخص تحمل به کم آبی، برآورد تنوع ژنتیکی برای طول کلئوپتیل و بررسی نقش طول کلئوپتیل در نحوه واکنش به تنش انجام شد. مقایسه میزان عملکرد و اجزای آن در ژنوتیپ های گندم نان مناطق خشک و نیمه خشک ایران انجام گرفت. در این تحقیق 50 ژنوتیپ در شرایط تنش آبی و عادی بر پایه طرح بلوک های کامل تصادفی با سه تکرار موردمطالعه قرار گرفتند. نتایج تجزیه واریانس نشان داد که بین ژنوتیپ ها در هر دو شرایط محیطی ازلحاظ کلیه صفات به جز صفت تعداد سنبله در واحد سطح اختلاف معنی داری وجود داشت و دامنه تغییرات برای کلیه صفات دارای طیف نسبتا بالایی بود که نشان دهنده تنوع بالا بین ژنوتیپ های موردمطالعه بود. میانگین تمام صفات به جز وزن سنبله اصلی و طول ریشک، در شرایط معمولی بیش تر از شرایط تنش رطوبتی بود. طول کلئوپتیل ژنوتیپ ها بین 2.41 تا 4.91 سانتی متر بود. در بین نه صفت موردمطالعه، تعداد شش صفت دچار کاهش رشد ناشی از اعمال تنش خشکی گردیدند و از این میان کاهش تعداد سنبله، عملکرد دانه در سطح و وزن سنبله از همه قابل توجه تر بود. سه ژنوتیپ شیرودی، اروم و پاستور متحمل ترین و ژنوتیپ استار دارای کمترین مقدار STI نسبت به تنش کم آبی بود. برای بررسی ارتباط صفات و شاخص مقاومت به خشکی با طول کلئوپتیل، ضریب همبستگی محاسبه گردید. بیشترین همبستگی مثبت در هر دو شرایط محیطی (تنش و بدون تنش) میان صفات ارتفاع بوته با طول کلئوپتیل به ترتیب به میزان 0.56 و 0.43 و تعداد سنبله با طول کلئوپتیل به ترتیب به میزان 0.16 و 0.165 بود. همبستگی طول کلئوپتیل تحت شرایط تنش و بدون تنش با شاخص STI منفی بود. بین عملکرد دانه و طول کلئوپتیل همبستگی منفی و غیر معنی داری وجود داشت. ضریب همبستگی طول کلئوپتیل با برخی صفات کمیتی در شرایط تنش نسبت به شرایط عدم تنش کم آبی ازنظر اندازه و جهت تغییر نمود که ناشی از نقش موثر طول کلئوپتیل در موازنه گیاه و شرایط رطوبتی است

    کلیدواژگان: اجزای عملکرد، تحمل، تنش رطوبتی، همبستگی
  • رضا شهریاری*، حسین شهبازی، نسیم هجران، سمیه سیف برقی صفحات 57-71

    به منظور ارزیابی کارایی صفات فیزیولوژیکی در گزینش تحمل به تنش خشکی گیاه جو، آزمایشی با 19 ژنوتیپ جو در قالب طرح بلوک های کامل تصادفی با سه تکرار در دو محیط تنش خشکی و بدون تنش در دانشگاه آزاد اسلامی اردبیل در سال زراعی 1395-1394 اجرا گردید. بعد از اعمال تنش، صفات محتوی آب نسبی برگ، هدایت روزنه ای، فلورسانس کلروفیل (Fv/Fm)، اتلاف آب از برگ جداشده، سطح ویژه برگ و سرعت پوشش زمین اندازه گیری شدند. نتایج تجزیه واریانس صفات نشان داد که اثر خشکی بر صفات محتوی آب نسبی برگ، اتلاف آب از برگ جداشده، سطح ویژه برگ و سرعت پوشش زمین معنی دار ولی بر Fv/Fm و هدایت روزنه ای معنی دار نبود. در شرایط بدون تنش، ژنوتیپ شماره 13با عملکرد 5040 کیلوگرم در هکتار پرمحصول ترین ژنوتیپ و در شرایط خشکی ژنوتیپ های 13 و 15 با عملکرد 2710 و 2550 کیلوگرم در هکتار برترین ژنوتیپ ها بودند. در شرایط بدون تنش عملکرد فقط با سرعت پوشش زمین، همبستگی نشان داد، در حالی که در شرایط تنش، همبستگی عملکرد دانه با محتوی آب نسبی برگ، هدایت روزنه ای، سطح ویژه برگ و سرعت پوشش زمین مثبت و با اتلاف آب برگ جدا شده منفی بود. در تجزیه رگرسیون چندگانه به روش گام به گام تحت شرایط خشکی، صفات هدایت روزنه ای، سرعت پوشش زمین و اتلاف آب از برگ جدا شده در مدل رگرسیونی باقی مانده و 69.3 درصد تغییرات عملکرد دانه را توجیه کردند. تجزیه کلاستر، ژنوتیپ های متحمل را به خوبی از ژنوتیپ های حساس جدا نمود. نتایج نشان داد که سرعت پوشش زمین با داشتن قوی ترین همبستگی با عملکرد دانه و کمترین مقدار اثر متقابل ژنوتیپ× محیط، می تواند به عنوان مناسب ترین معیار غیر مستقیم گزینش تحمل به خشکی در گیاه جو مد نظر قرار گیرد. صفات هدایت روزنه ای، تعرق غیر روزنه ای، محتوی آب نسبی برگ و سطح ویژه برگ نیز می توانند در اولویت بعدی قرار گیرند.

    کلیدواژگان: تحمل خشکی، سرعت رشد اولیه، فلورسانس کلروفیل، محتوی آب نسبی برگ، هدایت روزنه ای
  • کاوه قادری، سلیمان محمدی*، محمدرضا داداشی، عزیز مجیدی صفحات 73-84

    یکی از راهکارهای مقابله با تنش خشکی انتهای فصل در زراعت جو، تولید ارقام جدید متحمل می باشد که در شرایط مختلف محیطی پایداری عملکرد داشته باشند. با توجه به پیچیدگی برهمکنش آب و مقدار نیتروژن مصرفی در تظاهر عملکرد بالقوه گیاه، این پژوهش با هدف ارزیابی واکنش ژنوتیپ های جو به مقادیر مختلف نیتروژن (شاهد، 50، 100 و 150 کیلوگرم در هکتار کود اوره) در شرایط آبیاری نرمال و تنش کم آبی آخرفصل، بصورت آزمایش کرت های خرد شده در قالب طرح بلوک های کامل تصادفی با سه تکرار طی سال های 1395-1393 در ایستگاه تحقیقات کشاورزی میاندوآب اجرا شد. سطوح مختلف نیتروژن در کرت های اصلی و ژنوتیپ های جو در کرت های فرعی قرار گرفتند. نتایج حاصل از تجزیه مرکب نشان داد که اثر سال، رقم، نیتروژن و برهمکنش سال در رقم برای هر دو شرایط آبیاری معنی دار بود. مقایسات میانگین نشان داد رقم بهمن و لاین EBYT-84-10 بیش ترین مقدار عملکرد دانه را در هر دو شرایط آبیاری داشتند. همچنین نتایج حاصل از تجزیه به مولفه های اصلی نشان داد که رقم بهمن در شرایط عدم مصرف، ژنوتیپ های بهمن و EBYT-84-10 در سطح 50 و 100 کیلوگرم و ژنوتیپ EBYT-84-10 در سطح 150 کیلوگرم کود نیتروژن، بیشترین تحمل به تنش خشکی را داشتند. در کل نتایج این تحقیق نشان داد که نیاز کود نیتروژن ارقام جو بسته به فراهمی مقدار آب تغییر نموده و لذا مصرف بی رویه کود نیتروژن علاوه بر افزایش هزینه برای کشاورز ممکن است محیط زیست را آلوده نماید و بنابراین بایستی با احتیاط مصرف گردد.

    کلیدواژگان: جو، شرایط نرمال و تنش، عملکرد دانه، کود اوره
  • محمد علیزاده، نظام آرمند*، مجید رستمی، سعیدرضا حسین زاده صفحات 85-96

    اسیمیلاسیون خالص CO2 از طریق فرایند فتوسنتز، اولین مرحله تولید زیست توده است. به منظور بررسی اثرات تنش کمبود آب بر شاخص های فتوسنتزی 3 رقم زراعی نخود در مراحل گیاهچه ای، گلدهی و غلاف دهی پژوهشی در سال 1394 به اجرا درآمد. آزمایش به صورت فاکتوریل در قالب طرح کاملا تصادفی با سه تکرار در شرایط کنترل شده بود. دو فاکتور مورد آزمایش در این مطالعه شامل ارقام نخود زراعی (عادل، آزاد و کرج) و تنش آبی در پنج سطح 20، 40، 60، 80 و 100 درصد رطوبت در حد ظرفیت زراعی بودند. نتایج مقایسه میانگین ها نشان داد که تحت شرایط تنش کم آبی شدید (20 و 40 درصد ظرفیت زراعی) کلیه صفات مورد بررسی در مقایسه با شرایط بدون تنش کاهش معنی داری داشتند. نتایج در مرحله گیاهچه ای نشان داد که در شرایط بدون تنش، میزان فتوسنتز خالص، CO2 درون سلولی، محتوای کلروفیل برگی، تعرق و کارایی فتوسیستم II در رقم کرج نسبت به رقم عادل به ترتیب 29%، 13%، 23%، 21% و 3% بیشتر بود. در مرحله گلدهی و در شرایط بدون تنش، محتوای کلروفیل برگی و فتوسنتز خالص در مقایسه با رقم عادل 14% و 17% و در مقایسه با رقم آزاد به ترتیب 29% و 43% بیشتر بود. در شرایط تنش 40 درصد ظرفیت زراعی CO2 درون سلولی و فتوسنتز خالص به صورت معنی داری در رقم کرج افزایش داشت. در مرحله غلاف دهی در سطوح 60 و 100 درصد ظرفیت زراعی رقم کرج با محتوای کلروفیل 2.76 و 4.70 میلی گرم بر گرم وزن تر برگ نسبت به دو رقم دیگر برتری داشت. بر اساس نتایج پژوهش حاضر رقم کرج به دلیل برتری ویژگی های فتوسنتزی نسبت به دو رقم دیگر پس از انجام پژوهش های تکمیلی می تواند قابلیت معرفی به عنوان رقم متحمل به خشکی را داشته باشد.

    کلیدواژگان: تنش آبی، تعرق، فتوسنتز خالص، فتوسیستم II، محتوای کلروفیل
  • مریم میردورقی، محمدصادق تقی زاده، علی بهپوری* صفحات 97-108

    به منظور بررسی تاثیر تنش آبی بر اندام های هوایی، ریشه و عملکرد گندم دوروم در کشت مخلوط ژنوتیپ ها، آزمایشی به صورت فاکتوریل در قالب طرح کاملا تصادفی با 3 تکرار در گلخانه تحقیقاتی دانشکده کشاورزی و منابع طبیعی داراب، دانشگاه شیراز در سال 97-96 اجرا شد. تیمارهای آزمایشی با استفاده از مخلوط ارقام و لاین ها شامل: شبرنگ، بهرنگ و لاین های DW-92-4 و DW-94-14 به صورت کشت خالص و کشت مخلوط ژنوتیپ ها در ترکیب های دوتایی و چهارتایی بودند. تیمار تنش شامل دو سطح (آبیاری نرمال و تنش آبی) بر مخلوط ژنوتیپ ها اعمال شد. نتایج تجزیه واریانس نشان داد که اثر تنش و سیستم های کشت و اثر متقابل تنش×سیستم های کشت بر عملکرد دانه معنی دار بود (p≤0.01). مقایسه میانگین اثر متقابل نشان داد که بیشترین عملکرد دانه مربوط به ترکیب کشت مخلوط شبرنگ + بهرنگ (8.75 گرم در بوته) در شرایط آبیاری نرمال و کمترین آن نیز مربوط به ترتیب کشت خالص DW-92-4 با میانگین 1.1 گرم در بوته که با تیمار کشت مخلوط DW-92-4 و DW-94-14 با میانگین 1.20 گرم، کشت خالص بهرنگ با میانگین 1.25 گرم، کشت مخلوط بهرنگ+DW-92-4 با میانگین 1.25، کشت خالص شبرنگ با میانگین 45/1، کشت خالص DW-94-14 با میانگین 50/1، کشت مخلوط چهار ژنوتیپ DW-92-4 و DW-94-14+شبرنگ+بهرنگ با میانگین 1.75، کشت مخلوط شبرنگ+ بهرنگ با میانگین 2.35 (در شرایط تنش آبی) و کشت مخلوط شبرنگ+DW-94-14 با میانگین 1.45 (در شرایط آبیاری نرمال) اختلاف آماری معنی داری نداشت. بالاترین همبستگی مثبت و معنی دار بین عملکرد دانه با ارتفاع گیاه و وزن هزار دانه و طول برگ به ترتیب **r=0.443 و **0.434=r و *0.312=r مشاهده شد. به طورکلی، نتایج به دست آمده نشان دهنده این است که کشت مخلوط دو ژنوتیپ شبرنگ+بهرنگ در شرایط آبیاری نرمال نسبت به کشت خالص یک ژنوتیپ در شرایط تنش آبی از عملکرد دانه بالاتری برخوردار بود. همچنین، بیشترین عملکرد در حالت تنش آبی به کشت مخلوط شبرنگ+ DW-92-4 اختصاص یافت.

    کلیدواژگان: تنش خشکی، تنوع ژنتیکی، عملکرد دانه، مخلوط ارقام، نسبت ریشه به اندام هوایی
  • خوشناز پاینده*، مانی مجدم، نازلی دروگر صفحات 109-119

    به منظور مطالعه خواص کیفی و عملکرد دانه کلزا رقم هایولا 401 در واکنش به محلول پاشی کود ریزمغذی مرکب آهن، روی و منگنز تحت تنش قطع آبیاری، این تحقیق در سال زراعی 97-1396 در منطقه آب و هوایی حمیدیه به صورت کرت های خرد شده در قالب طرح بلوک های کامل تصادفی در چهار تکرار اجرا شد. تیمارهای آزمایش شامل تنش قطع آبیاری در دو سطح آبیاری مطلوب، قطع آبیاری در مرحله خورجین دهی در کرت های اصلی و محلول پاشی کود مرکب ریزمغذی آهن ، روی و منگنز در چهار سطح شامل عدم محلول پاشی (شاهد)، و محلول پاشی با غلظت های دو در هزار، چهار در هزار و شش در هزار در کرت های فرعی بودند. نتایج نشان تنش قطع آبیاری بر شاخص سطح برگ، عملکرد دانه، میزان پروتئین دانه، عملکرد پروتئین، درصد آهن و روی دانه تاثیر معنی داری داشت. همچنین با افزایش غلظت کود ریزمغذی، عملکرد دانه، میزان پروتئین دانه، عملکرد پروتئین، درصد آهن و روی دانه افزایش یافت. در شرایط آبیاری مطلوب و محلول پاشی با غلظت شش در هزار بالاترین مقادیر بدست آمد که این نتایج با تیمار محلول پاشی با غلظت چهار در هزار تفاوت معنی داری نداشت. بیشترین عملکرد دانه با میانگین 3290.4 کیلوگرم در هکتار در شرایط آبیاری مطلوب و محلول پاشی چهار در هزار بدست آمد. در این آزمایش محلول-پاشی عناصر ریزمغذی موجب کاهش خسارت ناشی از تنش قطع آبیاری بر عملکرد دانه و نیز افزایش درصد آهن و روی دانه گردید. به طور کلی می توان نتیجه گرفت اگرچه تنش قطع آبیاری باعث کاهش رشد و عملکرد کلزا شد ولی استفاده از عناصر ریزمغذی به میزان چهار در هزار توانسته تا 35% کاهش عملکرد را جبران کند.

    کلیدواژگان: درصد پروتئین، شاخص سطح برگ، عملکرد پروتئین، درصد آهن
  • عزیز مجیدی*، پرنگ امیری صفحات 121-129

    در شرایط تنش ، همزیستی گونه های قارچ میکوریزا-آربوسکولار با ریشه گیاه میزبان، تاثیر مستقیمی بر تحمل خشکی در گیاهان دارد. به منظور بررسی تاثیر دو گونه قارچ میکوریزا-آربوسکولار در سطوح مختلف تنش رطوبتی بر برخی ویژگی های رشدی ذرت، این آزمایش به صورت فاکتوریل با دو عامل در قالب طرح پایه کاملا تصادفی با پنج تکرار در شرایط گلخانه اجرا گردید. عامل اول مربوط به سطوح تنش رطوبتی شامل 60، 80 و 100% ظرفیت زراعی و عامل دوم مربوط به دو گونه قارچ میکوریزا شامل Glomus intraradices و Glomus mosseae و شاهد (عدم تلقیح) بودند. نتایج نشان داد که تنش رطوبتی موجب کاهش ارتفاع بوته و وزن خشک اندام هوایی به ترتیب به میزان13% و17% شد. تنش رطوبتی بر وزن خشک ریشه بی تاثیر بود ولی، قارچ های مایکوریزا وزن خشک ریشه را افزایش داده و تاثیر G. mosseae نسبت به گونه G. intraradices بیشتر بود. علیرغم افزایش شدت تنش رطوبتی، قارچ های مایکوریزا شاخص کلروفیل SPAD را افزایش داد. بیشترین شاخص کلروفیل مربوط به تیمار تلقیح با قارچ G. mosseae در 0.6 ظرفیت زراعی معادل 37.02 بود. گیاه تلقیح شده با قارچ G. mosseae نسبت به G. intraradices کارایی بیشتری در حفظ رطوبت نسبی آب برگ در شرایط تنش رطوبتی داشت. بیشترین درصد کلونیزاسیون ریشه معادل 39.04 در تیمار تلقیح با قارچ mosseae G. در 60% رطوبت زراعی به دست آمد. به طورکلی، نتایج پیشنهاد می کنند که در شرایط تنش رطوبتی، گونه G. mosseae قادر به برقراری ارتباط همزیستی موثرتری با ریشه گیاه ذرت تحت شرایط انجام این آزمایش بود.

    کلیدواژگان: تنش رطوبتی، شاخص کلروفیل، کلونیزاسیون ریشه، همزیستی مایکوریزائی
  • محمود محمدی، سیدعلی محمد مدرس ثانوی*، همت الله پیردشتی، بهنام زند، زین العابدین طهماسبی سروستانی صفحات 131-143

    خشک سالی مشکل شایعی است که بصورت جدی کمیت و کیفیت تولیدات کشاورزی را تحت تاثیر قرار می دهد. استفاده از تکنیک های زراعی از جمله تقویت شرایط بیولوژیک خاک می تواند در کاهش اثرات تنش خشکی موثر باشند. در رابطه با این موضوع آزمایشی بصورت مزرعه ای در دو منطقه تهران (نیمه خشک) و ورامین (خشک) در سال 94-1393 انجام شد. آزمایش به صورت اسپلیت فاکتوریل در قالب طرح بلوک های کامل تصادفی در سه تکرار اجرا شد. عامل اصلی شامل سه تیمار بدون تنش آبی، تنش متوسط و تنش شدید (آبیاری در زمان 30، 40 و 50 درصد ظرفیت زراعی) بود و ترکیب فاکتوریل شامل سه رژیم کود شیمیایی (بدون مصرف، مصرف 50 و 100 درصد نیتروژن + فسفر مورد نیاز گیاه)، قارچ میکوریزایی (کاربرد و عدم کاربرد در زمان کاشت) و باکتری آزوسپیریلوم (کاربرد و عدم کاربرد در زمان کاشت بذر، مرحله 7 و 14 برگی) به عنوان عامل فرعی در نظر گرفته شد. نتایج نشان داد که عملکرد دانه، عملکرد بیولوژیک، وزن 1000 دانه، تعداد دانه در بوته، تعداد کپسول در بوته و تعداد شاخه جانبی در بوته با کاهش آبیاری به طور معنی داری در شرایط آب و هوایی خشک در منطقه ورامین کاهش یافت. تلقیح میکوریزا همراه با کاربرد توام کودهای شیمیایی و آزوسپیریلوم باعث بهبود میزان عملکرد دانه، عملکرد بیولوژیک، وزن 1000 دانه، تعداد دانه در بوته، تعداد کپسول در بوته و تعداد شاخه جانبی در بوته در شرایط تنش خشکی شد. میزان عملکرد بیولوژیک و دانه در شرایط عدم وجود تنش خشکی به همراه کاربرد کودهای شیمیایی و بیولوژیک نسبت به شرایط وجود تنش شدید خشکی به همراه عدم کاربرد کودهای شیمیایی و بیولوژیک به ترتیب به میزان 60 و 65 درصد برای منطقه تهران و 50 و 59 درصد برای منطقه ورامین افزایش یافت. تنش خشکی باعث کاهش میزان عملکرد و استفاده از کودهای بیولوژیک سبب مقاومت گیاه به خشکی گردیده است.

    کلیدواژگان: آزوسپیریلوم، فسفر، کم آبیاری، میکوریزا، نیتروژن
  • سیده سمیرا طباطبایی، محسن جهان، کمال حاج محمدنیا قالی باف* صفحات 145-154

    کودهای زیستی یکی از مهترین منابع تامین عناصر غذایی در کشاورزی پایدار محسوب می شوند. بدین منظور پژوهشی به صورت کرت های خردشده در قالب طرح پایه بلوک های کامل تصادفی با 3 تکرار در مزرعه تحقیقاتی دانشگاه فردوسی مشهد در سال 1394 انجام شد. سطوح آبیاری در 3 سطح شامل: 100، 75 و 50 درصد نیازآبی لوبیا به عنوان عامل اصلی و نوع کود شامل: کود زیستی نیتروکسین، کود زیستی بیوفسفر، کود شیمیایی نیتروژنه (اوره) و شاهد (بدون کود) به عنوان عامل فرعی بودند. نتایج آزمایش نشان داد که کودهای مورد بررسی بر عملکرد دانه و تعداد غلاف در بوته لوبیا تاثیر معنی دار (0.05≥P)، و بر تعداد دانه در غلاف و وزن صد دانه لوبیا تاثیر بسیار معنی داری (0.01≥P) داشتند. در این میان، کود زیستی نیتروکسین بیشترین تاثیر را نشان داد و صفات مورد بررسی را به ترتیب 92.4، 101.7، 47.3 و 38.7 درصد نسبت به تیمار شاهد افزایش داد. اثر سطوح آبیاری نیز بر تمام صفات لوبیا خیلی معنی دار (0.01≥P) بود، به طوری که کمترین مقدار صفات مذکور در تیمار 50 درصد نیازآبی لوبیا مشاهده شد و نسبت به تیمار 100 درصد نیازآبی به ترتیب 68.1، 35.8، 56.3 و 38.1 درصد کاهش نشان داد. اثر متقابل کود و آبیاری تنها بر عملکرد ماده خشک لوبیا معنی دار (0.05≥P) بود، به طوری که بیشترین و کمترین عملکرد ماده خشک به ترتیب در نتیجه ی کاربرد کود نیتروکسین با تامین 100 درصد نیازآبی (7741 کیلوگرم در هکتار) و شاهد (بدون کود) در شرایط 50 درصد نیازآبی (880 کیلوگرم در هکتار) بدست آمد. به طورکلی، کاربرد نیتروکسین منجر به بهبود معنی دار تمام صفات لوبیا شد و در اثر کاربرد بیوفسفر نیز در مقایسه با کود شیمیایی اوره، اکثر صفات لوبیا تفاوت معنی دار نداشتند، بنابراین می توان جهت تولید محصول سالم لوبیا با عملکردی برابر با نظام های رایج از این کودهای زیستی بهره جست.

    کلیدواژگان: بیوفسفر، حبوبات، کود اوره، نیازآبی، نیتروکسین
  • عبدالله ساجدی، نورعلی ساجدی* صفحات 155-169

    به منظور بررسی تاثیر مصرف بیوچار و پرایمینگ بذر و محلول پاشی با آب و سالیسیلیک اسید بر صفات فیزیولوژیکی و عملکرد روغن گلرنک در شرایط دیم، آزمایشی بصورت کرت های دوبار خرد شده در قالب طرح بلوک های کامل تصادفی در سه تکرار در سال زراعی 96-1395 در مزرعه تحقیقاتی دانشگاه آزاد اسلامی واحد اراک اجرا شد. عوامل مورد آزمایش شامل بیوچار حاصل از چوب، شاخه و برگ درختان در سه سطح عدم مصرف، 5 و10 تن در هکتار، پرایمینگ بذر در سه سطح بدون پرایمینگ، پرایمینگ بذر با آب مقطر و پرایمینگ بذر با 0.5 میلی مولار سالیسیلیک اسید و محلول پاشی در دو سطح محلول پاشی با آب و یک میلی-مولار سالیسیلیک اسید بودند. نتایج نشان داد که مصرف 5 تن در هکتار بیوچار و پرایمینگ بذر با سالیسیلیک اسید میزان آب حفظ شده برگ را نسبت به شاهد به میزان 24.9 درصد افزایش داد. کاربرد 5 تن در هکتار بیوچار میزان نشت یونی سلول را نسبت به شاهد به میزان 15 درصد کاهش و عملکرد روغن را نسبت به شاهد 20 درصد افزایش داد. مصرف 10 تن در هکتار بیوچار و پرایمینگ با سالیسیلیک اسید نسبت به شاهد محتوای کلروفیل a را 43.4 درصد افزایش داد. بیشترین محتوای کارتنوئید ها از کاربرد 5 تن در هکتار بیوچار توام با محلول پاشی با آب حاصل شد. با مصرف 5 تن در هکتار بیوچار وزن خشک گل نسبت به شاهد 27 درصد افزایش نشان داد. نتایج نشان داد با مصرف 5 تن در هکتار بیوچار توام با پرایمینگ و محلول پاشی با آب یا پرایمینگ توام با محلول پاشی با سالیسیلیک اسید صفات فیزیولوژیکی و عملکرد روغن بهبود یافت.

    کلیدواژگان: حفظ آب برگ قطع شده، رنگدانه های فتوسنتزی، کود آلی، نشت یونی، هورموپرایمینگ
  • مهشید سالاری، حمید سودائی زاده*، محمدعلی حکیم زاده، رستم یزدانی بیوکی صفحات 171-183

    به منظور بررسی تاثیر کائولین بر افزایش مقاومت به کم آبیاری در گیاه ریحان بنفش (Ocimum basilicum var purpurascens)، آزمایشی به صورت فاکتوریل در قالب طرح بلوک های کامل تصادفی در سه تکرار در گلخانه تحقیقاتی دانشگاه یزد در سال زراعی 97-1396 انجام شد. تیمارهای آزمایش شامل فاکتورهای کم آبیاری در چهار سطح ظرفیت زراعی معادل 25، 50، 75 و 100 درصد و محلول پاشی کائولین در سه سطح صفر، 3 و 6 درصد بود. نتایج نشان داد که اثر محلول پاشی کائولین و تیمارهای تنش رطوبتی بر ارتفاع، قطر ساقه، سطح برگ، وزن خشک اندام هوایی، وزن خشک ریشه، حجم ریشه، محتوای نسبی آب، کلروفیل a، کلروفیل b، کلروفیل کل، پرولین و قند محلول ریحان در سطح یک درصد معنی دار بود. با افزایش تنش به سطح 25 درصد ظرفیت زراعی، ارتفاع گیاهان با 14 درصد کاهش مواجه شد. با افزایش سطوح محلول پاشی کائولین تا غلظت 3 درصد تاثیر معنی داری روی ارتفاع مشاهده نشد، ولی با افزایش غلظت کائولین به 6 درصد، کاهشی برابر با 18.1 درصد مشاهده شد. گیاهان تیمارشده در عدم مصرف و مصرف کائولین در سطح 3 درصد بدون اختلاف معنی دار از بالاترین وزن خشک اندام هوایی برخوردار بودند. محلول پاشی غلظت های بالای کائولین (6 درصد) اثرات منفی روی رشد گیاه داشت. نتایج اثر متقابل کم آبیاری و کائولین حاکی از آن بود که کاربرد کائولین در سطوح (3 و 6 درصد) و تیمار رطوبتی 100 درصد ظرفیت زراعی دارای بیشترین میزان کلروفیل a بود. اثرات متقابل کم آبیاری و کائولین نشان داد که بیشترین محتوای نسبی آب (RWC) در تیمار 100 درصد ظرفیت زراعی و محلول 6 درصد کائولین و کمترین آن با کاهش 14.44درصد مربوط به اثر متقابل تنش 25 درصد ظرفیت زراعی و عدم کاربرد کائولین بود. نتایج این تحقیق بیانگر نقش مثبت کائولین تا غلظت 3 درصد در کاهش اثرات ناشی از تیمارهای کم آبیاری بر گیاه ریحان بود.

    کلیدواژگان: پرولین، قندهای محلول، محتوای کلروفیل، ویژگی های مورفولوژیکی
  • رسول اسدی، فرزاد حسن پور*، میترا مهربانی، امین باقی زاده، فاطمه کاراندیش صفحات 185-195

    مدیریت صحیح آب در مزرعه، باعث استفاده بهینه از منابع آب، خاک، کود و تولید محصولاتی با کمیت و کیفیت بالا را امکان پذیر می سازد. در این راستا به منظور ارزیابی دو سیستم آبیاری قطره ای سطحی و زیرسطحی در شرایط اعمال سطوح مختلف مکش رطوبتی بر گیاه رزماری، آزمایشی در قالب طرح کرت های نواری یک بار خردشده بر پایه طرح بلوک های کامل تصادفی، با سه تکرار در ایستگاه تولید نهال شهرداری کرمان در سال زراعی 1394اجرا شد. در این آزمایش سه آستانه پتانسیل (40، 60 و 80 سانتی بار جهت شروع آبیاری) به عنوان عامل اصلی ودو سیستم آبیاری قطره ای (سطحی و زیرسطحی) به عنوان عامل فرعی، مورد مقایسه قرار گرفتند. نتایج تحقیق نشان داد که صرفه جویی 44.6 میلی متری آب (21.7 درصد) بین نقاط پتانسیلی 60 و 40 سانتی بار، در شرایطی باعث کاهش 12.5 درصدی وزن خشک اندام هوایی، 12.8 درصدی تعداد شاخه زایا و 11 درصدی ارتفاع بوته شد که افزایش 10.5 درصدی بهره وری آب را در پی داشت. این در حالی بود که اعمال سطح پتانسیلی 80 سانتی بار در مقایسه با سطح پتانسیلی 60 سانتی بار باعث کاهش 33.4 درصدی وزن خشک اندام هوایی، 22.9 درصدی تعداد شاخه زایا و 22.5 درصدی ارتفاع بوته شد و تنها افزایش 4.5 درصدی بهره وری آب را در پی داشت. از طرف دیگر وزن خشک اندام هوایی در آبیاری زیرسطحی به مقدار 48 گرم در هر مترمربع بیشتر از آبیاری سطحی بود. این در حالی بود که به رغم صرفه جویی 10 درصدی مصرف آب در آبیاری زیرسطحی نسبت به آبیاری سطحی، بهره وری آب در این سیستم 21.4 درصد بیشتر بود. صفات ارتفاع بوته و تعداد شاخه زایا در آبیاری قطره ای زیرسطحی به ترتیب 8.2 و 8.7 درصد نسبت به آبیاری سطحی بیشتر بود. بنابراین استفاده از آبیاری قطره ای زیرسطحی در سطح پتانسیلی 60 سانتی بار در کشت گیاه رزماری در شهر کرمان می تواند راهکاری مناسب برای صرفه جویی در مصرف آب و افزایش بهره وری آب در دوره های خشک سالی باشد.

    کلیدواژگان: آبیاری قطره ای سطحی و زیرسطحی، تنش خشکی، شاخص سطح برگ، کرمان، مکش رطوبتی
  • محمد دشتکی*، محمدرضا بی همتا، اسلام مجیدی، رضا عزیزی نژاد صفحات 197-210

    تنش کم آبی از مهم ترین عوامل کاهش رشد بخصوص در مرحله جوانه زنی گیاه است. لذا جهت بررسی اثر خشکی با استفاده از محلول پلی اتیلن گلیکول (PEG 6000) بر شاخص های جوانه زنی و همبستگی سی ژنوتیپ گندم نان تحت تنش (0، 4-، 8- و 12- بار) در آزمایشگاه بذر پردیس کشاورزی و منابع طبیعی دانشگاه تهران در سال 1396 به صورت فاکتوریل در قالب طرح کاملا تصادفی در سه تکرار مورد ارزیابی قرار گرفتند. نتایج نشان داد که بین ژنوتیپ ها و سطوح مختلف تنش و اثرات متقابل آن ها اختلاف معنی داری وجود داشت. در این آزمایش رقم حیدری بالاترین درصد و سرعت جوانه زنی (به ترتیب برابر 98.7 درصد و 35.9) و طول ریشه چه (10.2 سانتی متر) را داشت و حال آنکه رقم آذر (به ترتیب با 73.3 درصد،20.7 و 2.9 سانتی متر) پایین ترین مقدار را دارا بود. ازلحاظ طول ساقه چه و شاخص بنیه بذر رقم سرداری به ترتیب با 5.6 سانتی متر و 520.1 بالاترین و رقم گاسکوژن به ترتیب با 2.8 سانتی متر و 257.2 پایین ترین مقدار را نشان دادند. همچنین ازلحاظ صفات وزن تر و وزن خشک گیاهچه، رقم روشن به ترتیب با 0.5 و 0.12 گرم بالاترین و رقم الوند به ترتیب با 0.21 و 0.40 گرم پایین ترین مقدار را داشت. بین طول ریشه چه و درصد و سرعت جوانه زنی و شاخص جوانه زنی در شرایط مطلوب و بین اکثر صفات در شرایط تنش همبستگی مثبت و معنی داری مشاهده شد. تجزیه به عامل ها نشان داد که صفات همبسته طول ریشه چه و ساقه چه، درصد و سرعت جوانه زنی، شاخص جوانه زنی و بنیه بذر و وزن خشک گیاهچه در عامل اول و صفات همبسته وزن تر و خشک گیاهچه در عامل دوم حدود 72 درصد از تغییرات موجود در کل داده ها را توجیه و بیشترین تاثیر را در جوانه زنی بذور داشتند. تجزیه کلاستر نیز ارقام گندم را در 4 کلاستر با خصوصیات درون گروهی مشابه و بین گروهی غیرمشابه گروه بندی نمود.

    کلیدواژگان: درصد جوانه زنی، ژنوتیپ، سرعت جوانه زنی، شرایط نرمال و تنش خشکی
  • سعید قوام سعیدی نوقابی، مصطفی یعقوب زاده، علی شهیدی، حسین حمامی* صفحات 211-223

    خشکی و شوری ازجمله تنش های محیطی هستند که به عنوان عوامل مهم کاهش تولید محصولات زراعی محسوب می شوند. به منظور ارزیابی واکنش گندم رقم آنفارم 4 به سطوح مختلف آبیاری و سطوح شوری، آزمایشی به صورت فاکتوریل بر پایه طرح بلوک های کامل تصادفی با سه تکرار در سال زراعی 96-1395 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه بیرجند انجام شد. تیمارهای آزمایش شامل سطوح مختلف آبیاری (شامل 125، 100، 75 و 50 درصد نیاز آبی گیاه و تیمار دیم با یک آبیاری تکمیلی) و دو سطح آب غیر شور  و شور به ترتیب معادل 1.4 و 5.4 دسی زیمنس بر متر بود. نتایج آزمایش نشان داد که اثر سطوح مختلف آبیاری بر تمامی صفات مورد مطالعه شامل ارتفاع گیاه، سطح برگ، طول سنبله، وزن هزار دانه، وزن تر تک بوته، وزن خشک تک بوته، تعداد دانه در سنبله، عملکرد بیولوژیک، عملکرد دانه و شاخص برداشت معنی دار بود (0.001<P). این در حالی است که اثر شوری آب آبیاری بر ارتفاع گیاه، سطح برگ و وزن هزار دانه معنی دار بود، ولی بر بقیه صفات اثری نداشت. اثر متقابل سطوح آبیاری و شوری آب آبیاری اثر معنی دار بر همه صفات به جز سطح برگ، طول سنبله و عملکرد دانه را نشان داد. نتایج این آزمایش نشان داد که بیشترین و کمترین مقدارها برای صفات مختلف به ترتیب در تیمارهای 125 درصد نیاز آبی گیاه و دیم با یک آبیاری تکمیلی مشاهده شد که درصد کاهش برای صفات وزن هزار دانه، تعداد دانه در سنبله، عملکرد بیولوژیک، عملکرد دانه و شاخص برداشت به ترتیب برابر 64٪، 62٪، 61٪، 89٪ و 75٪ بود. به طورکلی نتایج این مطالعه نشان داد که شوری آب آبیاری تا 5.4 دسی زیمنس بر متر تاثیر منفی بر عملکرد دانه گندم رقم آنفارم 4 ندارد.

    کلیدواژگان: شاخص برداشت، عملکرد دانه، عملکرد بیولوژیک، گندم، نیاز آبی
  • فاطمه نوری*، حسن اعتصامی، حمید نجفی زرینی، نیر اعظم خوش خلق سیما، غلامعلی رنجبر صفحات 225-235

    با توجه به اهمیت اثرات تنش شوری در کاهش رشد گیاهان، این مطالعه با هدف بررسی اثر باکتری های محرک رشد گیاه (جداشده از گره‏ های گیاه یونجه) بر کاهش اثرات تنش شوری در گیاه یونجه انجام شد. بدین منظور 63 جدایه باکتریایی از گره های 13 نمونه گیاه یونجه کشت شده در مزارع استان قم جداسازی شد. میزان مقاومت به شوری و برخی ویژگی‏های محرک رشد این جدایه‏ ها مورد ارزیابی قرار گرفت. درنهایت، سه جدایه برتر شامل دو جدایه غیر ‏ریزوبیومی A36 و A37 و یک جدایه ریزوبیومی ARh29 برای آزمایش گلخانه ای انتخاب شدند. آزمایش گلخانه‏ ای به صورت یک طرح کاملا تصادفی در قالب فاکتوریل در سه تکرار انجام شد. سطوح شوری شامل صفر، 50، 100، 150 و 200 میلی‏مولار کلرید سدیم و سطوح باکتری شامل گیاهان تلقیح شده با جدایه‏ های A36 + A37، ARh29، A36 + A37 + ARh29، شاهد منفی (گیاهان بدون تلقیح باکتریایی و تغذیه شده با هوگلند فاقد نیتروژن) و شاهد مثبت (گیاهان بدون تلقیح باکتریایی و تغذیه شده با هوگلند حاوی نیتروژن) بودند. نتایج نشان داد سویه‏های باکتریایی در تمام سطوح شوری، توانستند وزن خشک گیاه و پرولین را در مقایسه با گیاهان بدون تلقیح باکتریایی افزایش دهند. همچنین سویه های باکتری جذب یون های پتاسیم را افزایش و جذب یون های سدیم را در گیاهان یونجه تحت تنش شوری کاهش دادند به ‏طوری‏که در شوری 200 میلی‏مولار، وزن خشک و میزان پرولین گیاهانی که با هر سه جدایه برتر به ‏طور هم‏‏زمان تلقیح شده بودند، 29% و 35% بیشتر از شاهد مثبت و همچنین نسبت پتاسیم به سدیم آن ها به میزان 36% بیشتر از شاهد مثبت بود. به طور کلی، نتایج این مطالعه نشان داد که گره‏های ریشه یونجه می‏تواند حاوی باکتری‏های غیر ریزوبیومی محرک رشد گیاه و مقاوم به شوری باشد که استفاده از آن ها به همراه باکتری‏های ریزوبیومی می‏تواند منجر به بهبود رشد گیاه یونجه تحت تنش شوری گردد.

    کلیدواژگان: باکتری های غیر ریزوبیومی، _ Klebsiella sp، Kosakonia cowanii، تثبیت نیتروژن، باکتری‏های ریزوبیومی
  • محمود دژم، مجید رجایی*، شیما جوهری، سیروس طهماسبی صفحات 237-250

    به منظور بررسی اثر محلول ‏پاشی نیتروژن، کلسیم و پتاسیم بر ویژگی‏های مورفو-فیزیولوژیکی زیره سبز تحت تنش شوری، آزمایشی به صورت فاکتوریل در قالب طرح پایه کاملا تصادفی با سه تکرار انجام شد. عامل اول سطوح شوری در سه سطح شاهد (محلول نیم هوگلند)، محلول نیم هوگلند+ 75 میلی‏ مولار کلرید سدیم و محلول غذایی نیم هوگلند+ 150 میلی‏ مولار کلرید سدیم و عامل دوم محلول‏ پاشی در پنج سطح شاهد (آب مقطر)، نیترات کلسیم، نیترات پتاسیم، نیترات آمونیوم، نیترات کلسیم + نیترات پتاسیم بود. نتایج نشان داد که افزایش سطح شوری سبب کاهش وزن خشک بوته، محتوای کلروفیل a و b برگ در زیره سبز در مقایسه با تیمار شاهد گردید. تنش شوری 75 میلی ‏مولار نتوانست محتوای نسبی آب برگ زیره سبز را کاهش دهد، اما تنش شوری 150 میلی‏ مولار سبب کاهش محتوای نسبی آب برگ در مقایسه با تیمار شاهد شد. محلول‏ پاشی کلسیم و پتاسیم سبب افزایش پایداری غشاء و کاهش نشت یونی در زیره سبز در مقایسه با تیمار شاهد گردید. تنش شوری باعث افزایش محتوای سدیم در اندام هوایی و با بر ‏هم زدن تعادل کاتیونی، مانع از جذب کاتیون های دیگری مانند کلسیم و منیزیم گردید. استفاده از ترکیبات مختلف محلول‏ پاشی در تنش شوری 75 میلی‏ مولار، توانست از کاهش تعداد چتر در بوته و تعداد دانه در چتر جلوگیری کند. در این سطح شوری میزان وزن خشک بوته، تعداد چتر در دانه، کلروفیل a، وزن هزار دانه در محلول‏ پاشی نیترات کلسیم + نیترات پتاسیم نسبت به شاهد افزایش 49.1، 46.9، 30.0 و 40.9 درصدی نشان دادند. سرانجام نتایج نشان داد که نیتروژن، کلسیم و پتاسیم تاثیرات مخرب شوری را تا حدودی بهبود بخشیده و باعث افزایش تحمل گیاه به تنش شوری گردیده است.

    کلیدواژگان: کلسیم، محتوای نسبی آب برگ، نشت یونی، وزن هزار دانه
  • جلال خورشیدی* صفحات 251-261

    ارزیابی شاخصه های جوانه زنی تحت شرایط تنش شوری یکی از راهکار های سریع در انتخاب گیاهان مقاوم به این تنش است. بدین منظور بذور چهار گیاه دارویی ریحان (.Ocimum basilicum L)، آویشن دنایی (Thymus daenensis Celak)، زوفا (Hyssopus officinalis L.) و بادرشبی (Dracocephalum moldavica L.) تحت تاثیر شش تیمار مختلف شوری (0، 3، 7، 10، 15 و 20 دسی زیمنس بر متر) به صورت فاکتوریل بر پایه طرح کاملا تصادفی در سه تکرار قرار گرفت و شاخصه های جوانه زنی آنها مورد ارزیابی قرار گرفتند. نتایج نشان داد که بذور هیچ کدام از گیاهان مذکور در شوری 10 دسی زیمنس بر متر و بالاتر قادر به جوانه زنی نبودند. اثر متقابل شوری در گونه ی گیاهی بر اکثر صفات اندازه گیری شده غیر از طول ساقه چه، طول گیاهچه و سرعت جوانه زنی تاثیر معنی داری داشت. بیشترین درصد جوانه زنی (63.3 درصد) در سطح شوری صفر دسی زیمنس بر متر متعلق به آویشن دنایی و در سطوح شوری 3 دسی زیمنس بر متر (76.6 درصد) و 7 دسی زیمنس بر متر (80 درصد) متعلق به بذور ریحان بود. بیشترین سرعت جوانه زنی در تمام سطوح شوری مربوط به بذور ریحان بود. براساس شاخص تحمل، بیشترین میزان تحمل به شوری (0.0384- در سطح شوری 3 دسی زیمنس بر متر و 0.0084- در سطح شوری 7 دسی زیمنس بر متر) مربوط به بذور ریحان بود و کمترین میزان تحمل در سطح شوری 3 و 7 دسی زیمنس بر متر به ترتیب به آویشن دنایی (0.0034-) و زوفا (0.0027+) اختصاص داشت.

    کلیدواژگان: درصد جوانه زنی، شاخص بنیه ی بذر، شاخص تحمل، کلرید سدیم
  • علیرضا برجیان بروجنی*، عبدالمهدی بخشنده، سیدعطاالله سیادت، خلیل عالمی سعید، محمدرضا جلال کمالی صفحات 263-271

    به منظور بررسی دوره های کوتاه مدت تنش گرما بر محتوای کربوهیدرات محلول دم گل آذین و اندازه دانه گیاه گندم در مزرعه آزمایش حاضر 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. تیمارهای آزمایشی شامل چهار ژنوتیپ گندم بهاره بود. تنش گرما (حداکثر 35 سانتی گراد) با نصب اتاقک های تولید تنش حرارتی بر 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 تجزیه واریانس نشان داد اختلافات معنی داری در سطوح تنش گرما و صفات ژنوتیپ ها وجود دارد. تنش گرما (H1 یا H2) باعث کاهش معنی دار وزن تک دانه و تعداد دانه در سنبله گردید. وزن تک دانه در بین ژنوتیپ های تحت تنش دو هفته پس از گرده افشانی بین 4.5 تا 17 درصد کاهش یافت. بر اساس تعداد دانه در سنبله و وزن هزار دانه ژنوتیپ های اترک، چمران و اروند متحمل به گرما شناخته شدند. تنش گرما (میانگین H1 و H2) حداکثر محتوای کربوهیدرات محلول دم گل آذین را 26 درصد و میزان انتقال آن را 15 درصد کاهش داد. کاهش معنی دار کربوهیدرات محلول دم گل آذین از 21 روز پس از گرده افشانی شروع شد. کاهش در وزن تک دانه و در بین ژنوتیپ ها به طور منفی با حداکثر محتوای کربوهیدرات محلول دم گل آذین ارتباط داشت. در همه ژنوتیپ ها انتقال بیشتر کربوهیدرات در شرایط تنش با افزایش اندازه دانه همراه بود. در این آزمایش همبستگی معنی داری بین تعداد دانه در سنبله با وزن تک دانه و میزان کربوهیدرات انتقال یافته به دست نیامد. نتایج حاکی از آن بود که ژنوتیپ های چمران و اترک با ذخایر کربوهیدرات ساقه بالاتر و انتقال بیشتر آن در رشد و نمو دانه تحت شرایط تنش گرما برتری دارند.

    کلیدواژگان: دم گل آذین، قندهای محلول، گرما، وزن دانه
  • حسین کمائی*، حمیدرضا عیسوند، ماشاالله دانشور، فرهاد نظریان صفحات 273-283

    به‏ منظور بررسی اثر محلول‏ پاشی روی و بور بر سهم انتقال مجدد مواد فتوسنتزی در عملکرد دانه گندم نان تحت تنش گرمای انتهایی، آزمایشی به‏ صورت کرت‏های خرد شده فاکتوریل با سه تکرار در شهرستان رامهرمز واقع در جنوب غربی ایران اجرا گردید. عوامل آزمایشی شامل تاریخ کاشت در دو سطح مناسب (30 آبان) و تاخیری (15 دی) به‏ عنوان عامل اصلی و محلول‏ پاشی در چهار سطح با آب (شاهد)، روی، بور و روی + بور و دو رقم گندم نان پیشتاز و چمران 2 به‏ صورت فاکتوریل به‏ عنوان عامل فرعی بودند. نتایج نشان داد که تنش گرمای انتهایی ناشی از تاخیر در کاشت انتقال مجدد مواد فتوسنتزی ذخیره‏ ای از ساقه و سنبله به دانه و سهم نسبی ذخایر ساقه و سنبله در عملکرد دانه را به‏ طور معنی‏ داری افزایش داد، اما میزان فتوسنتز جاری و سهم نسبی آن در عملکرد و عملکرد دانه هر دو رقم گندم نان را به‏ طور معنی‏ داری کاهش داد. محلول‏ پاشی روی و بور بجز میزان فتوسنتز جاری و سهم نسبی آن در عملکرد و عملکرد دانه، همه صفات مورد اندازه ‏گیری را در هر دو تاریخ کاشت مناسب و تاخیری به‏ طور معنی‏ داری کاهش داد. رقم چمران 2 نسبت به رقم پیشتاز در صفات میزان فتوسنتز جاری، سهم نسبی فتوسنتز جاری در عملکرد و عملکرد دانه از برتری معنی‏ داری برخوردار بود، اما در سایر صفات، رقم پیشتاز برتری معنی‏ داری داشت. در بین همه صفات مورد اندازه‏ گیری، فتوسنتز جاری بیشترین سهم را در افزایش عملکرد دانه هر دو رقم گندم نان در هر دو تاریخ کاشت مناسب و تاخیری داشت. به‏ طور کلی، استفاده از محلول‏ پاشی روی یا روی + بور در رقم چمران 2 به‏ عنوان بهترین ترکیبات تیماری به‏ منظور کاهش اثرات زیان‏بار تنش گرمای انتهایی و بهبود عملکرد دانه در هر دو تاریخ کاشت مناسب و تاخیری توصیه می‏شود.

    کلیدواژگان: ارقام گندم، تاریخ کاشت، عناصر میکرو، فتوسنتز جاری
  • حسین کمائی*، حمیدرضا عیسوند صفحات 285-295

    به‏ منظور بررسی اثر محلول ‏پاشی آهن، روی و منگنز بر صفات فیزیولوژیک، زراعی و پروتئین گندم تحت تنش گرمای انتهای فصل، آزمایشی به‏ صورت کرت‏ های خرد شده با چهار تکرار در شهرستان رامهرمز اجرا گردید. فاکتورهای آزمایشی شامل تاریخ کاشت در دو سطح مناسب (15 آبان) و تاخیری (30 آذر) به‏ عنوان عامل اصلی و محلول‏ پاشی عناصر غذایی کم مصرف در شش سطح عدم محلول‏ پاشی (شاهد)، محلول‏ پاشی با آب، آهن، روی، منگنز و آهن + روی + منگنز به ‏عنوان عامل فرعی بودند. نتایج نشان داد، تاخیر در کاشت به ‏دلیل تنش گرمای انتهایی بجز محتوای پرولین برگ و پروتئین 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 آهن، روی و منگنز توانست صفات اندازه‏ گیری شده در تاریخ‏ کاشت مناسب و تاخیری را به‏ طور معنی‏ داری افزایش دهد. در این میان، کاربرد محلول ‏پاشی روی بیشترین اثر را در کاهش آسیب ناشی از تنش گرمای انتهایی بر صفات مورد اندازه ‏گیری نشان داد. به‏ طور کلی، کاشت در تاریخ 15 آبان و استفاده از عناصر غذایی کم مصرف به ‏ویژه روی به‏ صورت محلول‏ پاشی می‏تواند اثرات زیان‏بار ناشی از تنش گرمای انتهایی را کاهش و موجب بهبود صفات فیزیولوژیک، زراعی و محتوای پروتئین دانه گندم نان در منطقه شود.

    کلیدواژگان: تاریخ کاشت، عناصر ریزمغذی، گندم
  • لیلا فهمیده*، علی اصغر قادری، ایوب مزارعی، امیر رجبی صفحات 297-312

    تنش ناشی از فلزات سنگین یکی از مهمترین انواع تنش ها در اکوسیستم خاک است که باعث کاهش تولید محصول در واحد سطح می گردد. امروزه کاربرد ترکیبات فنولی و تنظیم کننده رشد گیاه مانند اسید سالیسیلیک به منظور کاهش آثار منفی ناشی تنش های مختلف مطرح است. هدف از مطالعه حاضر، ارزیابی تاثیر محلول پاشی اسید سالیسیلیک بر سمیت آرسنیک در گیاه ریحان پس از افزودن آرسنیک به خاک بود. این پژوهش در سال 1395 به صورت فاکتوریل در قالب طرح کاملا تصادفی با سه تکرار انجام شد. تیمارهای آزمایشی شامل تنش آرسنیک در چهار سطح صفر (شاهد)، 10، 45، 80 میلی گرم در کیلوگرم خاک و محلول پاشی اسید سالیسیلیک سه سطح صفر (شاهد)، 1 و 2 میلی مولار بود. نتایج نشان داد که افزودن آرسنیک به طور معنی-داری وزن تر و خشک، سطح برگ و رنگیزه های فتوسنتزی را کاهش و غلظت کربوهیدارت و آنزیم های آنتی اکسیدانی کاتالاز و پراکسیداز را افزایش داد. درحالی که محلول پاشی اسید سالیسیلیک بر تمام صفات تاثیر معنی داری داشت؛ به طوری که غلظت 2 میلی مولار باعث افزایش وزن تر و خشک، سطح برگ، کلروفیل a، b، کل و کارتنوئید و کاهش فعالیت آنزیم های کاتالاز و پراکسیداز شد. در این بررسی اثر متقابل بین اسید سالیسیلیک و آرسنیک بر رنگیزه های فتوسنتزی و آنزیم های آنتی اکسیدان معنی دار بود؛ و اسید سالیسیلیک نقش تعدیل کننده و کاهنده اثر منفی سمیت آرسنیک را بر این خصوصیات داشت. بنابراین با استناد به یافته های مطالعه حاضر و همچنین انجام تحقیقات تکمیلی می توان محلول پاشی اسید سالیسیلیک را جهت بهبود رشد و کاهش سمیت آرسنیک در گیاه دارویی ریحان تحت تنش آرسنیک پیشنهاد کرد.

    کلیدواژگان: اسید سالیسیلیک، تنش عناصر سنگین، گیاه دارویی، محلول پاشی
  • مهدی کریمی*، بابک خیام باشی، سیدعلی محمد چراغی، مجید نیکخواه، محمدحسن رحیمیان، هادی پیراسته انوشه، مهدی شیران تفتی، ولی سلطانی گردفرامرزی صفحات 317-322

    پژوهش حاضر به منظور بررسی اثر مقادیر متفاوت فسفر (0، 100، 200 و 300 کیلوگرم سوپرفسفات تریپل در هکتار) بر عملکرد و اجزای عملکرد گندم در شرایط متفاوت شوری (1.88، 7.22 و 16.14 دسی زیمنس برمتر) به صورت یک آزمایش بصورت کرت های خردشده بر پایه طرح بلوک های کامل تصادفی در مرکز ملی تحقیقات شوری اجرا گردید. نتایج نشان داد که با افزایش شوری آب آبیاری همبستگی بین عملکرد گندم و فسفر کاهش یافت. الگوی پاسخ گندم به مصرف فسفر در شوری های آب آبیاری 1.88 و 7.22 دسی زیمنس بر متر از معادله درجه دوم تبعیت کرد، لیکن این همبستگی در شوری آب آبیاری 7.22 دسی زیمنس بر متر از نظر آماری معنی دار نبود. در شوری آب آبیاری 16.14 دسی زیمنس بر متر، عکس العمل دانه گندم به فسفر از الگوی خاصی تبعیت نکرد و فسفر نتوانست تاثیر معنی داری بر عملکرد دانه گندم داشته باشد. طبق نتایج این تحقیق مصرف 150 کیلوگرم کود سوپرفسفات تریپل در شوری های آب آبیاری 1.88 و 7.22 دسی زیمنس بر متر توصیه می شود. ضمنا نتایج این پژوهش نشان داد که با افزایش شوری نیاز گندم به کود فسفری کاهش یافت، و امکان جبران کاهش عملکرد ناشی از تنش شوری با افزایش میزان مصرف کود فسفری امکان پذیر نیست.

    کلیدواژگان: آب آبیاری، اجزای عملکرد، سوپرفسفات تریپل
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  • Farzaneh Fakhimi, Alireza MotallebiAzar, Fariborz ZareeNahandi, Nemat SokhandanBashir, Gholamreza Gohari * Pages 1-8
    Introduction

    Potato (Solanum tuberosum) is an important crop in tropical countries. Salinity stress is the crucial factor that seriously limits agricultural production in various regions especially in arid and semi-arid areas. Salicylic acid is a bioactive molecule that synthesizes via enzymatic and non-enzymatic pathways under stress conditions in different organs of plant, regulates and adjustments defense reactions of plant. Salicylic acid (SA) is known as a signalling molecule that modifies plant responses to pathogen infection. Many studies have shown that this compound can protect plant under oxidative stresses and maintain chlorophyll. In addition to being an important component of biotic stress tolerance mechanism, SA also regulates various aspects of plant responses to abiotic stresses through extensive signalling cross-talk with other growth hormones. However, exact mechanisms by which SA protects plants during abiotic stresses remain obscure. Salinity stress is the crucial factor that seriously limits agricultural production in various regions especially in arid and semi-arid areas. Salicylic acid is a bioactive molecule that synthesizes via enzymatic and non-enzymatic pathways under stress conditions in different organs of plant, regulates and adjustments defense reactions of plant. Salicylic acid (SA) is known as a signalling molecule that modifies plant responses to pathogen infection. Many studies have shown that this compound can protect plant under oxidative stresses and maintain chlorophyll. In addition to being an important component of biotic stress tolerance mechanism, SA also regulates various aspects of plant responses to abiotic stresses through extensive signalling cross-talk with other growth hormones. However, exact mechanisms by which SA protects plants during abiotic stresses remain obscure.

    Material and methods

    This experiment was conducted at the plant tissue culture laboratory of Horticultural Sciences, Department, University of Tabriz, Iran, during spring–summer of 2017. The present study was aimed to investigate of salicylic acid effect on betaine aldehyde dehydrogenase gene expression and glycine betainesynthesis in Solanum tuberosum cv. Agria under salinity stress on in vitro condition. The experiment treatments included four level of salycilic acid (0, 1, 10 and 100 mM) and two level of sodium chloride (0 and 70 mM). In the present study, MS media culture was used and sodium nitroprusside was applied for increasing the betaine aldehyde dehydrogenase gene expression (the responsible gene of glycine betaine synthesis) under salinity stress. Four weeks after treatment, total RNA of treated explants was extracted and semi quantitative RT-PCR was used for the analysis of expression of betaine aldehyde dehydrogenase gene.

    Results

    and semi quantitative RT-PCR was used for the analysis of expression of betaine aldehyde dehydrogenase gene. The glycinbetainecontent was measured with iodide potassium. The survey of betaine aldehyde dehydrogenase gene expression showed increased under salinity stress. Also salicylic acid increased the glycine betaine content in grown plantlets which were grown under normal condition.The expression pattern of glycine betain gene showed tha by increasing of salicylic acid and sodiuom chloride concentration the expression of glycine betain gene has been increased in all samples. however under salinity stress this compound showed negative effect on glycinbetaine content.

    Conclusion

    In conclusion, antioxidant activity, total phenol and protein were increased salinity stress. In addition, antioxidant activity and glycine betaine content during salt stress period was decreased application of nitric oxide. The glycine betaine content of plantlets in general condition with application of sodium Salicylic acid increased but under salinity stress, Salicylic acid had negative effect on glycine betaine content. The results of this research showed that exogenous application of salicylic acid increased the expression level of genes and lead to enhancement of plant tolerance to salinity stress. Further studies are necessary to determine optimum concentration and duration of Salicylic acid application in order to achieve maximum benefit in Solanum tuberosum tissue culture.

    Keywords: abiotic stress, Betaine aldehyde dehydrogenase, Glycin betaine, in vitro, Semi quantitative RT-PCR
  • Zobeyde Kohanpour, Atefeh Sabouri *, Ebrahim HezarJaribi, Ali Aalami Pages 9-26
    Introduction

    Soybean (Glycine max L.) is one of the most important oil seeds and its importance refer to its role in providing the essential fats needed to complete the human food pyramid similar to other oilseeds. In Iran, after cotton and canola, the highest cultivated land is dedicated to soybeans. The yield of plants such as soybeans is significantly reduced due to environmental stresses, especially drought stress. Thus the aim of the present study was an investigation of soybean advanced lines and parental varieties under non-stress and under water stress conditions to compare different genotypes and identification of more tolerant lines to water stress.

    Material and methods

    Plant materials consisted of 30 soybean genotypes including three parental varieties Sahar, Williams, Katoul and 27 advanced lines. The lines were derived from parental varieties Sahar×K778, Sahar×Hamilton, Sahar×Gorgan3, Sahar×Williams, Williams×Katoul, Hamilton×Katoul, Sahar×Katoul, Williams×K778, Williams×Hamilton, Gorgan3×Williams. The plants were cultivated in a filed with a total area of 400 m2 at Ezberam, Siahkal (N 37°1.3′8 ̋N, 49°54′10.5 ̋E) in the Guilan province of Iran in spring and summer 2016 as randomized block complete design under normal and water stress conditions with three replications. A total of 14 traits were measured including plant height, number of nodes, first pod height from ground, number of branches, total weight of plant, number of pods, weight of total pods, number of filled pods, weight of filled pods, pod length, number of seeds per pod, number of total seeds, weight of total of seeds and 100- seed weight.

    Results

    The combined analysis of variance revealed genotypes difference and genotype×conditions interaction were significant (p<0.01) for all of the traits except pod length that indicated high diversity among soybean genotypes and different responses of genotypes to normal and water stress conditions for measured traits. According to the cluster analysis Ward method, all genotypes were assigned to three groups under normal condition. The first group consist of five advanced lines Williams×Katoul3123, Williams×Katoul(4), Williams×Hamilton(2), Sahar×Hamilton(4), Gorgan3×Williams(2) and Katoul had higher mean based on all of agronomic and yield traits such as number and weight of pods, weight of total seeds and 100- seed weight than other genotypes. Under water stress condition genotypes were classified into three groups that third group consisting of four lines Sahar×Katoul(4), Williams×Hamilton(1), Williams×K778(3) and Williams×Katoul(4) had higher performance based on important yield traits including number of pod, weight of pod, number and weight of filled pods, number of seeds per pod, number of seeds in plant, total weight of seeds in plant and 100- seed weight than other genotypes.

    Conclusions

    According to comparisons mean, Gorgan3×Williams(2) had the highest weight of total pods (94.4gr), number of branches (14.11), number and weight seeds in plant (284.22 and 66.98 gr respectively) and 100-seed weight (35.74gr) under normal condition and the highest weight of total pods (63.28 gr), weight of filled pods (61.91gr), number and weight seeds in plant (236.44 and 44.11gr respectively) and 100-seed weight (33.67gr) belonged to Williams×Katoul(4). Also according to cluster analysis to comparing soybean genotypes under normal and water stress conditions, Williams×Katoul(4) in both groupings, belonged to the better group, indicating that the line was superior to other lines and its parents in terms of total traits. Totally, advanced lines performed better than their parents, especially under water stress condition. Also according to principal component analysis and biplot of two first PC, Gorgan3×Williams(2) under normal condition and Williams×Katoul(4) under both of conditions were better than other lines and parental varieties.

    Keywords: Cluster analysis, Drought stress, Oilseed, Principle component analysis
  • AliReza Rahi, Hamid NajafiZarrini *, Gholamali Ranjbar, Mahdi GhajarSpanlou Pages 27-40
    Introduction

    The annual rain in Iran is about one third of world average (235-260 milliliters). Arid, semi-arid, super arid and desert weather conditions constitute about 85% of Iran’s area which is due to low rain in central and southern regions. The researches have shown that all the country is confronted with dryness that greatly affects agriculture. If this condition continues, generating agricultural products such as bean will definitely face some problems. Now, the global production of soybean is more than 310 million tons equals 80 billion dollars. Soybean is one of the important products in Iran’s agriculture. According to the last published statistics, the area under cultivation of soybean in country is about 80 thousand hectares and Golestan, Mazandaran and Ardabil have allocated the rank of first to third to themselves. Functionally, it is about 110 to 130 thousand tons per year. Soybean has nutritional value for human, livestock and soil. Since drought stress is the most important environmental stress which has severely led to reduction in plants’ growth, reduction of bush generation and function of crops more than any other environmental factor; thus, health of soil and environment is necessary to provide nutritional security in order to identify the resistant plants and their cultivation be developed. Numerous methods have been used to select the high quality items under the condition of stress in the farm and greenhouse. Regarding that the genetic base of resistance to drought stress has many complexities, proper and extensive phenotypic assessment on the farm together with identifying the desirable physiological features will be useful in natural environments. Hence, this plant and identifying the genotypes resistant to drought stress were carried out to develop the cultivation.

    Materials and methods

    To evaluate the dehydration and evaluation of tolerance to drought stress in soybean genotypes in 2017, a research was conducted as a factorial test in form of total random blocks in three repetition in greenhouse in Damsvand County. The first factor contained 50 soybean genotypes and second factor included two levels of normal irrigation and irrigation disruption in time of podding. Assessing genotypes was conducted by using tolerance to drought indexes: SNPI,MSTI,YR,RDI DI,ATI,SSPI, MP,GMP,HARM,SSI,STI,TOL,YI,YSI,. The dimensions of vases were about 35 in 45 centimeters which were filled by soil, sand and fertilizer in proportion of 1: 1: 3. Five seeds were planted in each vase. They were irrigated every four day. In time of stopping the irrigation, about 50% of pods were constituted. Cultivation was done on 10th of Tir, 2017. And statistical analysis were done by SAS and JMP software. Diagrams were drawn by Excel software. There are significant variety of soybeans.

    Results and discussion

    Comparisons showed that resistant and sensitive genotypes shall be separated on the basis of tolerance to drought indexes, as such that genotypes 2, 14, 21, 38, 49 indicated high function in both environment and genotypes 25 and 23 showed high function in stress conditions. In order to recognize the most effective indexes, the indexes which have the highest correlation with the weight of seeds in both stressful and lack of stress conditions will be reliable and according to the obtained conclusions, some of tolerance to drought indexes had the highest significant correlation with the function in normal ans stressful conditions. Decomposing into main components make this ability to differentiate between the indexes introducing resistant genotypes and the indexes introducing sensitive genotypes, and accordingly, cluster decomposition of 8 groups among 50 genotypes determined that finally some of genotypes had desirable function in both environments. In order to recognize the most effective indexes, the indexes which have the highest correlation with the weight of seeds in both stressful and lack of stress conditions will be reliable and according to the obtained conclusions, Harmonic mean(HARM), geometric mean productivity(GMP), mean productivity(MP), stress tolerance index(STI), yield index(YI), Abiotic tolerance index (ATI), Drought resistance index) DI), Yield stability index(YSI), Stress susceptibility percentage index (SNPI), modified stress tolerance index(MSTIk1 and MSTIk2) of tolerance to drought indexes had the highest significant correlation with the function in normal ans stressful conditions. genotypes 2, 14, 21, 23, 42 and 49 have suitable function in both environments.

    Keywords: abiotic stress, Correlation Analysis, Irrigation, Yield
  • Fatemeh Darvishnia, MohammadHadi Pahlevani *, Khalil ZaynaliNezhad, Khosro Azizi Pages 41-56
    Introduction

    To investigate water stress tolerance indexes, estimation of genetic diversity for coleoptile length and other agricultural variables such as grain yield and its components and also investigating of the role of coleoptile length in response to water stress and its relation to yield and its components in wheat cultivars in arid and semi-arid regions of Iran.

    Materials and methods

    This study was performed in a randomized complete block design with 3 replications and 50 wheat genotypes under stress and non-stress water conditions. In this evaluation, the STI index was calculated based on grain yield of genotypes under stress conditions. For investigating the association of traits and drought tolerance index with coleoptile length the coefficient of correlation was calculated Analysis of variance of genotypes was performed using SAS software (ver. 9.1) for all traits.

    Results and discussion

    Analysis of variance showed that there was a significant difference between genotypes for plant height, days to heading, grain yield, spike weight, awn length, grain per spike, 1000-grian weight, and spike length in both stress and non-stress water conditions, however this was not significant for number of spike per unit. The results showed that except for awn length and spike weight, mean values of all traits in non-stress conditions were more than stress condition. The coleoptile length of genotypes was variable from 2.41 cm to 4.91 cm. The range for all traits in both stress and non-stress conditions was relatively high which indicated a high diversity between the studied cultivars. Among the nine studied traits, six of them suffered a decline in growth due to drought stress and so that reduction in number of spike with 4.38%, grain yield with 13% and spike weight with 14% were more obvious. In this evaluation, the STI index was calculated based on grain yield of genotypes under stress conditions. Six cultivars including Shirudi, Orum, Pasteur, S-90-5, Ofogh, and Sistan were the most tolerant and cultivar Star had the least amount of STI index. The highest positive correlation of coleoptile length.in both environmental conditions was occurred about plant height and number of spike. Correlation coefficients of plant height with coleoptile length under stress and non-stress conditions were was 0.56 and 0.43, respectively, and its correlations with number of spike were 0.16 and 0.165, too. A negative correlation between coleoptile length and STI index was observed in both stress and non-stress conditions. The correlation coefficient of coleoptile length with some agronomic changed in terms of size and direction over stress than non-stress conditions, therefore this could be inferred to effective role of coleoptile in the balance of plant and moisture conditions.

    Conclusions

    In general, the results of this study showed that the cultivars had a significant difference between sowing date and spike appearance, plant height, spike length, spike weight, 1000-grian weight, awn length, grain per spike and grain yield.

    Keywords: Correlation, tolerance, Water Stress, Yield components
  • Reza Shahriary *, Hossein Shahbazi, Nasim Hejran, Somaiieh Seifbarghi Pages 57-71

    In order to evaluate the drought tolerance of 19 barley genotypes using physiological traits, an experiment was carried out in randomized complete blocks with 3 replications under non-stress and terminal drought stress conditions at agricultural research station of Islamic Azad University, Ardabil branch in 2016. Non-stress plots were irrigated when available soil water reached to 60% using tensiometer measurements. In drought stress environment, plants were grown in rainfed condition and drought was imposed after flowering stage by a rain exclusion shelter. After exposure of plants to drought stress, Specific Leaf Area (SLA), Excised Leaf Water Loss (ELWL), leaf Relative Water Content (RWC), Stomatal Conductance (Gs), Chlorophyll Fluorescent (Fv/Fm) and Rate of Ground Cover (RGC) were measured in flag leaves of 10 randomly selected plants. Results of ANOVA showed that SLA, ELWL, RWC and GC affected by drought, however Fv/FM and stomatal conductance did not affected. Stress severity index was obtained as 0.45, indicating a moderate drought stress imposed to genotypes. G×E interaction was significant in all of the traits indicating the severity of the drought stress. In non-stress condition, genotype number 13 with 5040 kg/ha, had the highest grain yield. Under drought stress condition, genotypes number 13 and 15 with 2710 and 2550 kg/ha, had the highest grain yield respectively. Based on grain yield of the genotypes in both environments, genotypes number 13, 18(Bereke-54 check), 9, 4, 19 (Makouee check) and 15 had the highest stress tolerance index (STI). Under stress, genotypes number 15, 1, 18, 2, 3, 10, 13, 12 and 9 had the highest RWC, genotypes number 18, 13, 14 and 8 had the lowest ELWL, genotypes number 15, 9, 19, 18, 1, 13, 17, 4, 16, 5 and 12 had the highest Gs, genotypes number 9, 13, 8, 12, 14, 10, 11 and 15 had the highest RGC (early vigor), genotypes number 4, 3, 13, 15, 4, 12, 9, 17, 19, 1 and 11 had the highest SLA. In non-stress condition yield correlated only with RGC this trait was the only trait remained in final regression model and explained the 34.7% of grain yield variation. Under stress condition, yield positively correlated with RWC, SLA, Gs, RGC and negatively correlated with ELWL. In stepwise multiple regression analysis under drought stress condition, Gs, RGC and ELWL remained in final model with 0.489, 0.512 and 0.381 standard partial regression coefficients respectively(as direct effect). These three characters described 69.3% of grain yield variation. Cluster analysis using Euclidian distance by Ward’s method could successfully separate sensitive and tolerant genotypes. In this analysis, genotypes number 1, 4, 9, 12, 13, 15, 17, 18 and 19 were located in superior cluster, having higher Gs, RWC, SLA and lower Fv/FM. Finally genotype number 13 (the most high yielding genotype) had the second, third, fourth and sixth ranks in RGC, SLA, Fv/FM and Gs. The results of this experiment showed that RGC, having the highest correlation with yield and lower genotype × environment interaction can be consider as the most suitable indirect criteria for selection of drought tolerance in barley. Traits such as Gs, ELWL, RWC and SLA can be consider in the next priority, due to significant correlations with yield under drought stress.

    Keywords: Chlorophyll Fluorescent, Drought tolerance, Rate of Ground Cover, Relative Water Content, Stomatal Conductance
  • Kaveh Gadri, Soleiman Mohammadi *, MohammadReza Dadashi, Aziz Majidi Pages 73-84
    Introduction

    In west Azerbaijan for food production including barley, water stress is one of the most important threats and water deficit stress at grain filling stage do it damage every year. One approach for reducing of damage of water deficit stress is introducing of drought tolerant new barley variety. Effect interaction of water and nitrogen is complicated on plant. Under full irrigation condition, rate of nitrogen for grain mostly grain yield determinative factor, but in water deficit stress condition, high rate of nitrogen increased severity of tension, as a result growth and yield of plant reduced. For achieving of drought tolerant barley genotype, barley genotypes must be evaluated in water deficit stress and full irrigation conditions. The aim of this research was to evaluate the response of barley genotypes to application of different levels of urea fertilizer under different moisture conditions.

    Material and methods

    This research was carried out in order to evaluate the response of barley genotypes to application of different levels of urea fertilizer under complete irrigation and end season drought stress conditions, as a split plot based on randomized complete blocks design with three replications at Miandoab Agricultural Research and Natural Resources Station during 2014-2016 crop seasons. Four barley genotypes (Bahman, EDBYT-82-6، EDBYT-82-9، EBYT-83-17، EBYT-84-10) at different levels of nitrogen (0, 50, 100, 150 kg/ha urea) were evaluated in full irrigation and grain filing water deficit stress conditions. At planting time, 50 kg/ha urea applied for all treatments. All genotypes were planted with 400 seed/m2 in 6 lines by 5m length and 20cm apart at late of October month. Watering in the fall for a turn to green seeds and their deployment was carried out. In the spring for water deficit stress trial, irrigation at the heading time was cut and for normal trial was performed three times irrigation. Seedbed Preparation, potash and phosphate fertilizer, crop care and harvest for all treatment were the same. Compound analysis of data was carried out on two years. The SAS (Ver, 9.4) and Minitab (V. 16) software were used to data analysis.

    Results

    The results of combined analysis showed that effect of year, genotype, nitrogen and year*genotype was significant at both irrigation conditions. Mean comparisons showed genotypes of Bahman and EBYT-84-10 genotypes had the greatest grain yield in both of irrigation conditions. Under normal irrigation condition, grain yield increased until 100 kg/ha urea, application of 150 kg/ha of urea had no significant difference comparison to 100 kg/ha urea in view of grain yield, 150 kg/ha of urea produced 35% greater grain yield rather than 0kg/ha treatment. Under water deficit condition, application of 100 kg/ha of urea had no significant difference comparison to 50 kg/ha in view of grain yield, also application of 150 kg/ha of urea decreased 11% grain yield comparison to 0kg/ha treatment. Selection of drought tolerant genotypes in different nitrogen levels based on principal components analysis indicated that genotype Bahman at 0 kg/ha, genotypes Bahman and EBYT-84-10 at 50 and 100 kg/ha, and genotype EBYT-84-10 at 150 kg/ha nitrogen application had the highest drought tolerance.

    Conclusion

    Results of this study showed response of barley genotypes varied to rate of nitrogen, so under water deficit stress condition, nutritional need of barley genotypes less than full irrigation condition. So, in addition to the raise cost for farmer may be infecting the environment. Therefore, recommended in selecting of drought tolerant barley genotypes, special attention focus to rate of nitrogen.

    Keywords: Barley, Grain yield, Normal, stress condition, Urea fertilizer
  • Mohamad Alizadeh, Nezam Armand *, Majid Rostami, SaeedReza Hosseinzadeh Pages 85-96
    Introduction

    The water stress-induced limitation on plant growth is mainly caused by reductions in plant carbon balance, which depends on the balance between photosynthesis and respiration. In order to evaluate the water stress tolerant cultivar, photosynthetic parameters were investigated in seedlings of flowering and podding stages of Adel, Azad and Karaj arable chickpeas.

    Materials and methods

    The experiment was conducted as a factorial based on a completely randomized design with three replications under controlled conditions in 1394 with the aim of evaluating the effect of drought stress on 5 levels of 20, 40, 60, 80 and 100% of crop capacity on the photosynthetic index of cultivars. Pea, Adel, Azad and Karaj were planted in 3 stages of seedling, flowering and podding. Total Chl Content (TChl): The chlorophyll index was determined using the Chlorophyll Content Meter (CCM-200 plus, USA). Maximum quantum yield of PSII photochemistry (Fv / Fm), was measured using chlorophyll fluorimeter (Pocket PEA, Hansatech, England). transpiration rate (E) ،net photosynthetic rate (PN) and intercellular CO2 concentration(Ci) were determined in fully expanded leaves using a portable infrared gas analyzer (KR8700 system, Korea) Statistical analyses were made by MASTAT-C. Means were compared using the Duncan’s multiple range test (p 0.05).

    Results and discussion

    Fv/Fm: Drought stress in seedling stage at levels of 20 and 40% of crop capacity resulted in a significant reduction of Fv/Fm ratio in all three cultivars compared to non stress conditions. Results showed that drought stress levels (20, 40 and 60% of crop capacity) in all three cultivars resulted in a significant reduction in the efficiency of photosystem II compared to 80 and 100% of crop capacity. Comparison of mean of data on interaction effects of cultivar and stress in podding stage showed that chickpea cultivars did not differ significantly in this stage of growth in different conditions of drought stress. Related studies showed that the reduction of the Fv/Fm ratio in drought stress conditions, which indicates a reduction in the efficiency of photosystem II, is due to the reduction of electron transfer from the photosystem II to the photosystem I.TChl: In the seedling stage, the results showed that the highest and lowest total chlorophyll index was allocated to Karaj cultivar under non stress condition and free cultivar under severe stress conditions. At flowering stage, the results showed that drought stress at all levels resulted in a significant reduction of this trait compared to non-stress level. In the podding stage, Karaj cultivar was superior to free cultivar at most drought stress levels (20, 60 and 100% crop capacity). Related studies showed a sharp drop in chlorophyll content in high levels of stress, can reduce transmission of the required minerals and water leaves through transpiration reduce the suction of the vessel is wood.Transpiration: The results showed that drought stress at all levels significantly decreased transpiration rates in the cultivars compared to non-stressed conditions. At flowering stage, asignificant decrease in transpiration was observed in all levels of drought stress in all chickpea cultivars. Comparison of meanings in the podding stage was similar to that of flowering stage. Related studies have shown that plants reduce the transpiration by closing the stomata to counteract the drought stress in order to preserve leaf water and prevent it from wasting.Ci: The results showed that in seedling stage, drought stress at levels of 20 and 40% of crop capacity led to a significant reduction of CO2 in leaf cells compared to non stress conditions. In comparison with chickpea cultivars, in flowering and podding stage, Karaj cultivar had the highest amount of intracellular CO2 at all drought levels, which was significant at 20 and 80% of the capacity of this increase compared to the fair and free cultivars. Studies on the selection of susceptible and tolerant drought stress in plants have shown that reducing intracellular CO2 concentration due to the closure of leaf stomata and preventing the entry of CO2 into leaf mesophilic cells.Pn: Comparison of mean of data in flowering seedlings showed that the highest amount of pure photosynthesis in Karaj cultivar was under non stress condition. There was no significant difference between treatments in pod filling stage. The increase of pure photosynthesis in Karaj cultivar compared to two other cultivars (fair and free) indicates that there are mechanisms of tension compatibility in order to prevent the reduction of photosynthesis and tolerance of this variety to drought stress.

    Conclusions

    This study showed that drought stress in seedling, flowering and podding stages of Adel, Azad and Karaj chickpea cultivars resulted in a significant decrease in pure photosynthesis, transpiration, intracellular CO2, chlorophyll content and photosystem II performance. Although the Karaj cultivar, due to its superiority in most of the studied traits, is compared with the other two cultivars as drought stress tolerant to those two varieties.

    Keywords: Chlorophyll content, Net Photosynthesis, Photosystem II, Transpiration, Water Stress
  • Maryam Mirdoraghi, MohamadSadegh Taghizadeh, Ali Behpouri * Pages 97-108
    Introduction

     Durum wheat (Triticum durum) is predominantly grown in the Mediterranean area, the northern plains of the United States, Canada, Europe, and many parts of the Asia.(FAO, 2017).A large part of the wheat cultivated land in Iran is located in arid and semi-arid regions. Due to lack of water resources and consequently stress for plants, wheat yieldis significantly reduced. Unde rstanding the effect of drought stress on grain yield is an effective step in durum wheat production.(Garcia del moral et. al., 2003).

    Materials and Methods

    A factorial experiment with 2 factors in a completely randomized design with 3 replicates including durum wheat genotypes and water stress was conducted in the research greenhouse of College of Agriculture and Natural Resources of Darab in 2017-2018. Mixtures of 4 durum wheat genotypes (Behrang, Shabrang, Dw-92-4 and Dw-94-14) were planted in binary and quadruple combinations and pure culture. Plants were treated in two levels of water stress including normal irrigation and water stressed. Plants which went under water stress did not watereduntil the plants showed rolled leaves.
     

    Results and discussion

     The results of analysis of variance of yield and yield components are shown intable 1. Interactions ofwater stress and genotype mixtures on grain yield per plant, number ofseeds per spike, number of seeds per spikelet, one thousand seed weight were significant at the probability level of 0.01 (p≤0.01).This means that the response of the genotype mixtures to the same water stress was not the same and the amount of these losses due to water stress were higher for some of the genotype mixtures than others. (table 1). The results showed that the highest grain yield obtained in shabrang+behrang genotype mixture at normal irrigation level (8.75 g per plant) and the least grain yield was observed  in DW-92-4 pure crop under water stress conditions.(1.1 g per plant). The highest positive and significant correlation were observed between grain yield andplant height, 1000 grain weightand leaf length (r = 0.443 **) (r = 0.434 **) (r = 0.312 **) respectively.Some researchers revealed that grain yield in mixed crop combination with the same seeding rate is 15 to 23 percent superior to pure crop cultivation.(Nazeri et al., 2004).

    Conclusions

     In general, the results indicated that the combination of genotypes under normal irrigation conditions, than pure culture as an agro-ecological method have some, positive effects on grain yield and other agronomical traits.The highest positive and significant correlation was observed between grain yield andplant height, 1000 grain weightand leaf length (r = 0.443 **) (r = 0.434 **) (r = 0.312 **). According to the results of this experiment, it seems that under irrigation conditions, the use of genotype mixtures can produce more yield than pure culture of a genotype in greenhouse conditions.

    Keywords: Drought stress, Grain, Genetic diversity, Mixed cultivars, Root, Shoot
  • Khoshnaz Payandeh *, Mani Mojaddam, Nazli Derogar Pages 109-119
    Introduction

    One of the oil seeds that has attracted a lot of attention in these years in the country and is also considered as a major contributor to the plan to reduce the import of vegetable oil. This product is among the world's most oil-bearing grains It has the highest production in recent decades, and nowadays it has achieved the third place after the soybean and palm oil in vegetable oil products. Water is a key factor in the production of crops. The yield of crops in many areas is limited by living or non-living environmental stresses, and therefore, there is a significant difference between actual yield and yield potential of crops. Low moisture content in each of the different stages of growth reduces the absorption of water, nutrients, decreases the transfer of elements within the plant, and ultimately reduces the yield of the grain or the final product. Optimal water use is of great importance, especially in areas where dry climatic conditions And semi-arid dominant that covers about two thirds of Iran's territory. In order to increase yield per unit area, farmers use one of the common fertilization methods including soil utilization through irrigation, seed mixing and solubility. Leaf solubility is one of the fastest ways to meet the needs. The fertilizer is also used in this method to save fertilizer and in addition to the positive economic aspect, the environment is protected from chemical pollution, which is very effective in achieving sustainable agriculture.

    Materials and methods

    In order to investigate the effect of micronutrients application on qualitative and quantitative yield of rapeseed plants in condition drought stress, a field experiment was carried out to in Hamidieh city in 2017-18 in a split plot is an experiment in a randomized complete block design with four replications. The experimental treatments included drought stress in two levels (I1: optimal irrigation, I2: Irrigation off in pod stage) as the main plot and spraying of complete fertilizer in four levels (M0: non-spraying (control), Spraying with concentrations M1: 2 in thousand, M2: 4 per thousand, M3: 6 per thousand) was implemented as a subplot in the region.

    Results

    The results showed that drought stress had a significant effect on leaf area index, grain yield, grain protein, protein yield, iron and zinc percentage. The highest grain yield in optimal irrigation treatment (with an average of 3110.7 kg /ha) and the lowest grain yield (with an average of 2280.22 kg /ha) was attributed to irrigation cut off treatment at slaughtering stage. Also, with increasing micronutrient levels, leaf area index, grain yield, protein content, protein yield, percentage of iron and zinc increase. The most of these traits were obtained from optimal irrigation and spraying of six to a thousand, which did not have significant difference with treatment of four. In explaining the reason for the increase in the protein content of seeds by the application of micronutrients on zinc and iron, it should be noted that these elements directly contribute to both the process of gene expression and protein synthesis. The deficiency of zinc prevents the activation of a number of antioxidant enzymes, which results in oxidative damage to protein molecules, which also reduces protein function in the plant. The highest grain yield (with a mean of 3290.4 kg /ha) was obtained in irrigation treatment and spray application of four per thousand. In this experiment, micronutrient spraying reduced the damage caused by drought stress to grain yield and also increased the percentage of iron and zinc seeds.

    Conclusion

    The results of this experiment showed that using micronutrients such as iron and zinc can play an important role in improving grain yield, seed protein content and enrichment of zinc and iron in drought stress conditions. Regarding the drought and depletion crisis in Khuzestan province, nutrient poverty in the province's soils, especially in terms of micronutrients such as zinc and iron, is a foliar application of fertilizer to increase the amount of elemental elements in the plant. Therefore, in general, the results of this research can be argued that in order to achieve maximum quality yield and agronomic traits, rapeseed cultivation with micronutrient foliar application of four thousand in moisture conditions is recommended.

    Keywords: Iron percent, Leaf area index, Protein percent, Protein yield
  • Aziz Majidi *, Parang Amiri Pages 121-129
    Introduction

    Arbuscular-mycorrhizal fungi (AM) are important in sustainable agriculture because they increase the tolerance to drought stress in host plants. One of the most important aspects of the relationship between the mycorrhiza fungus and the host plant is that it’s physiological and biochemical processes should be such that the host plant can successfully deal with limiting environmental conditions.

    Materials and methods

    The isolates of the fungus used in this study included two Glomus (G.) genus species, G. intraradices and G. mosseae. In this research, their efficiency was evaluated on the improvement of some quantitative traits of corn under irrigated conditions and water stress in a calcareous soil. For this purpose, soil samples were prepared from a depth of 0-30 cm in a cultivated soil with a phosphorus available concentration of less than five mg.kg-1 and its physical and chemical properties were measured according to the standards of the Soil and Water Research Institute, Iran. The experiment based on factorial completely randomized design was carried out in five replications. The first factor was related to the drought stress levels of 60%, 80% and 100% of field capacity moisture (FC) and the second one consisted of two mycorrhizal fungi species, G. intraradices and G. mosseae, and control (non-inoculated). At the beginning of flowering, traits such as plant height, leaf area, chlorophyll index (using Spad-502 Minolta chlorophyll meter), relative humidity, were measured. At harvesting time, shoot dry weight, root dry weight and root colonization percentage were measured in all treatments.

    Results and discussion

    The results revealed that there was a significant difference between the drought stress levels in terms of plant height so that with increasing tension, plant height decreased. The effects of mycorrhizal fungus species were significant in terms of plant height and the highest plant height was obtained in inoculum treatment with G. intraradices. The interaction effects of drought stress and mycorrhizal fungi were also significant in terms of plant height. The highest plant height was obtained in the control treatment at field capacity, which was maintained by G. intraradices with the same moisture content and G. mosseae at 60% of soil moisture content in a statistical class, indicating the effectiveness of G. mosseae in improving Corn growth under moisture stress condition. Drought stress reduced the SPAD chlorophyll index, leaf area, root colonization percent, relative water content (RWC) of leaves, leaf area, root dry weight, and shoot dry weight of maize. In plants inoculated with mycorrhizal inoculation, the chlorophyll index, plant height, root dry weight, leaf surface area and root colonization percent and RWC of leaves were increased. Interactions between drought stress and mycorrhizal species on all mentioned parameters have a significant effect. Although, chlorophyll content was higher in plants inoculated with the fungus G. mosseae specie at 80% FC, but maximum shoot dry weight was obtained at 100% FC and inoculation with fungi G. intraradices treatment. The most root colonization was achieved in plants inoculated with the fungus G. mosseae specie at 60% FC treatment. Overall, the results of this study proved that inoculation of corn seeds with AM fungi increased leaf chlorophyll content and produced dry matter of the plant in moisture regimes less than field capacity. Further increase of the traits studied in this study such as plant height, chlorophyll index, leaf area, relative humidity, root and shoot production as a result of using G. mosseae compared to G. intraradices, suggests that G. mosseae species are more compatible and able to communicate more effectively with the root of corn in drought stress conditions. Therefore, to increase the tolerance of corn to drought stress and increase the water absorption efficiency, G. mosseae species is more efficient in similar conditions of this experiment.

    Keywords: Chlorophyll Index, Drought stress, Mycorhizal symbiosis, Root colonization
  • Mahmood Mohammadi, S. Ali Mohammad ModarresSanavy *, Hemmatolah Pirdashti, Behnam Zand, Zeinolabedin TahmasebiSarvestani Pages 131-143
    Introduction

    Drought is a common problem that seriously affects the quantity and quality of agricultural produce. More than 50% of the world's regions are located in dry and semi-arid regions. Plant growth decreases in drought stress. Water shortages in the world and in Iran have always been a limiting factor for plant cultivation. Drought is a common problem that seriously affects the quantity and quality of agricultural products, such as medicinal plants. The use of agronomic techniques, including soil biological conditions (using mycorrhiza and Azospirilum) and the use of chemical fertilizers, may be effective in reducing the effects of drought stress.

    Materials and methods

    In this regard, a field experiment was carried out in two regions of Tehran (semi-arid) and Varamin (arid) in the period of 2014-15. The experiment was split factorial in a completely randomized block design with three replications. The main factor consisted of three treatments without water stress, moderate stress and severe stress (irrigation at 50, 40 and 30 percent of field capacity), and the factorial arrangement consisted of three fertilizer regimes (no fertilizer application, 50 and 100 percent Nitrogen + Phosphorus application requirements for plant), mycorrhizal fungi and Azospirilum bacterium (application and non-application) were considered as a subplot. Drought stress treatments at flowering stage (during flowering until the end of the season) were applied based on soil crop capacity. The following steps were applied to apply water deficit treatments, respectively: First, the field capacity was obtained, first, a plot (length of two meters × two meters wide) from each experimental site completely up to the end of the plain wall of the water filled and was enclosed with plastic (to prevent water evaporation and error) to the soil completely saturated with water. After 48 hours, the water was removed by gravity from the coarse porosity, the plastic was removed from the plots, the soil sample was prepared and, after weighing, in an oven at 105° C for 24 clock was placed. The sample was then calibrated with a precision weighing scale and evaporated moisture content (soil moisture content).

    Results and discussion

    The results showed that grain yield and its components (biological yield, 1000 seed weight, number of seeds per plant, number of capsules per plant and number of lateral branches per plant) with irrigation reduction (moderate and severe), were significantly dry weather in the Varamin area decreased. Inoculation of mycorrhiza with combined application of chemical fertilizers and Azospirillum improved seed yield, biological yield, 1000 seed weight, seed number per plant, number of capsules per plant and number of lateral branches per plant under drought stress conditions in arid and semiarid regions. Biological and grain yield in terms of absence of drought stress along with application of chemical and biological fertilizers to the conditions of severe drought stress, with non-application of chemical and biological fertilizers were 60% and 65% respectively for Tehran region and 50% and 59% for Varamin area increased. Reducing the amount of photosynthesis, reducing carbon dioxide absorption, increasing transpiration and decreasing water absorption, increasing leaf temperature due to reduced transpiration and reduced absorption of food can be mentioned due to reduced biological yield and grain yield under drought stress.

    Conclusions

    In general, drought stress has reduced the yield and the use of biological fertilizers has caused the plant's resistance to drought stress.

    Keywords: Azospirillum, Mycorrhiza, nitrogen, Phosphorus, Water deficit
  • SeyedeSamira Tabatabaei, Mohsen Jahan, Kamal HajmohammadniaGhalibaf * Pages 145-154
    Introduction

    In recent years, by minimizing the use of chemical fertilizers and replacing them with biological fertilizers has become important as one of the key principles of sustainable agriculture. Common bean (Phaseolus vulgaris L.) is the world’s most important food legume. This staple considered as a nearly perfect food mainly because of its high protein content and abundant fiber, complex carbohydrates, and other daily food needs such as vitamins (folate) and minerals (Cu, Ca, Fe, Mg, Mn, and Zn). Water used in agricultural production as one of the most important environmental factors affecting plant growth and development, especially in arid and semi-arid climatic conditions of Iran is of special importance. Since biological facility for production increase in agriculture is use of terrestrial useful living tiny, that cause is becoming plant yield and growth increase.

    Materials and methods

    In order to study the effect of plant growth promoting Rhizobacteria and nitrogen chemical fertilizer on yield and yield component of bean (Phaseolus vulgaris L.) under water stress conditions, a split-plot design based on RCBD with three replications was conducted at Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad, Iran in 2015. Three levels of irrigation (to supply of 100, 75, and 50 percent water requirement) were assigned to main plots and different types of biofertilizers (1- Nitroxin, containing Azotobacter sp. & Azospirillum sp. as inoculation seed, 2- Biophosphor, containing Phosphate-solubilizing bacteria Bacillus sp. & Pseudomonas sp.) as inoculation seed, 3- Nitrogen chemical fertilizer (100 kg.ha-1 urea form), and 4- Control (no fertilizer) were assigned to sub plots. Irrigation levels according to irrigation requirements in each irrigation period were carried out by water meter device. The growth index of LAI (leaf area index) was determined randomly from 5 competing plants regarding the marginal effects from 1 real completed leaf stage to the end of the growing season (every 7 days; 12 steps). LAI index was calculated using equation (1). Leaf area was calculated by Leaf Area Meter device (Delta T, UK). At the end of growing season, yield and yield component were determined regarding the marginal effects from 5 m2 surfaces. Data analysis of variance and draw charts were done by Minitab Ver. 16, Slide Write Ver. 2, and Excel 2010 softwares. At the end, Means comparing did by Duncan's test at probability 5 percent.LAI= (1/GA) [(LA2+LA1)/2] (Equation 1)Where GA is ground area (m2), LA is leaf area (m2).

    Results and discussion

    According to the result, the effect of fertilizers was significant (P≤0.05) on grain yield, and number of pod per plant, and was very significant (P≤0.01) on number of seeds per pod, and 100 seed weight. Among these fertilizers, Nitroxin fertilizer had the highest effect on traits and was increased these compare to control 92.4, 101.7, 47.3 and 38.7 percent, respectively. Also the effect of irrigation levels on all of traits was very significant (P≤0.01). So that the lowest of traits were observed in 50 percent water requirement of bean and compare to 100 percent water requirement were decreased 68.1, 35.8, 56.3 and 38.1 percent, respectively. Interaction of fertilizer and irrigation was significant (P≤0.05) only on dry matter yield of bean, so that the highest and the lowest of dry matter yield were obtained from Nitroxin+100% water requirement (7741 kg.ha-1) and Control+50% water requirement (880 kg.ha-1), respectively. In general, the results of this experiment declared that there was no significant difference between using of Biophosphor and nitrogen chemical fertilizer concerning the effect on bean traits including: seed yield, pod no. per plant, seed no. per pod, 100 seeds weight.

    Conclusion

    The results showed that could be possible to produce the healthy production of bean, moreover, attain the optimum yield as equal as to conventional systems.

    Keywords: Biophosphor, Nitroxin, Pulses, Urea fertilizer, Water requirement
  • Abdollah Sajedi, NourAli Sajedi * Pages 155-169
    Introduction

    Safflower (Carthamus tinctorius L.) is one of the oldest oil seeds that due to deep and extensive root system is known for salt as well as drought tolerance. Seed priming with water and salt solution in plant increased germination percent and germination index under stress condition. The reported that seed priming with salicylic acid can protect the plants against abiotic stress. Salicylic acid has role protection in plants that are under environmental stress condition. The reported that salicylic acid increased plants resistance to biotic and abiotic stresses such as drought. Exogenous application of salicylic acid improved crops yield. The research showed that with application of salicylic acid increased the chlorophyll content. Biochar is a solid material that created from carbonization each type biomass includes weeds, crops residual and another wastage material with plant origin. Application of biochar increased available phosphorus, potash, magnesium and calcium content as compared without biochar. The reported that application of biochar retained water and nutrition and therefore could be increase wheat yield. The reported that application of biochar increased maize yield by 140% due to increasing of pH and nutrition in duration four years.

    Material and methods

    To evaluate the effect of biochar and seed priming with salicylic acid and water along with foliar application on physiological traits and oil yield of safflower in dry land condition, an experiment was performed as split- split plot based on randomized complete blocks design in three replications, at the Research Station of Islamic Azad University, Arak Branch, Iran, in during 2016-2017. Experiment factors were included biochar (wood, shoot and leaf of trees) in three levels of 0, 5 and 10 t/ha; seed priming in three levels of without priming, priming with water distillated and seed priming with .0.5mM salicylic acid and foliar application in two levels of foliar application with water and 1 mM salicylic acid. The cultivar safflower was ‘Esfahan native’. Seeds primed for 12 h at distillated water and salicylic acid solutions then dried at shade. Biochar was applied at 15 cm depth and under the seed, before from sowing and mixed with soil. Sowing done with 30 cm distanced rows with 15 cm spacing between plants in rows. The seeds were sown at 3-4 cm depth on middle March 2016. Foliar application of water and salicylic acid done in two stages of vegetative and reproductive growth at 17 h evening. Physiological traits measured in heading stage. Data were subjected to analysis of variance using SAS. Means were compared using the Duncan's multiple range test at 5% the confidence level.

    Results

    Results showed that application of 5 t/ha biochar along with seed priming by salicylic acid increased the excise leaf water retention by 24.9 % compared to control. Application of 5 t/ha biochar decreased ion leakage by 15% and increased oil yield by 20% compared to control. Application of 10 t/ha biochar along with seed priming by salicylic acid increased the chlorophyll a content by 43.4% compared to control. The highest of carotenoids content was obtained from application of 5 t/ha biochar combined with foliar application of water. Application of 5 and 10 t/ha biochar increased the flower fresh wieght. The maximum of head harvest index was recorded from application of 5 t/ha biochar combined with foliar application of water or salicylic acid and also from application of 10 t/ha biochar combined with foliar application of salicylic acid.

    Conclusion

    The result this research showed that seed priming by water or salicylic acid along with foliar application and application of biochar by shoot water improve and decrease of damage due to stress condition, could be moderated the effect drought stress. Therefore seed priming by water or salicylic acid along with application of 5 t/ha biochar combined with foliar application of water or salicylic acid in two stage in duration of growth improved physiological traits and oil yield of safflower in dry land condition.

    Keywords: Excise leaf water retention, Hormo priming, Ion leakage, Organic fertilizer, Plant pigments
  • Mahshid Salari, Hamid Sodaeizadeh *, MohammadAli Hakimzadeh, Rostam YazdaniBiouki Pages 171-183
    Introduction

    Drought stress is one of the important adverse factors that limits plant growth and productivity. Drought stress induces a range of physiological and biochemical responses in plants. Plants also respond and adapt to water deficit at both cellular and molecular levels, for instance through accumulation of osmolytes and proteins specifically involved in stress tolerance. Plants’ responses to water stress are also species and cultivar-dependent characteristics. Foliar application of kaolin has been evaluated for its ability to reduce the negative effects of water stress and to improve the physiology and productivity of Plants. The purpose of this research is to determine the effects of different kaolin concentrations, on the physiological and morphological characteristics of purple basil under deficit irrigation conditions.

    Materials and methods

    In order to investigate of Kaolin on increasing of drought tolerance of Basil, a factorial experiment was conducted based on randomized complete block design with 3 replications in researcher greenhouses of Yazd university during 2017-18 growing season. The treatments were four levels of deficit irrigation including: I1=25%FC, I2=50%FC, I3=75%FC, I4=100%FC field capacity and three levels of kaolin concentrations consisted of K1=0%, K2=3%, K3=6%. In a factorial experiment based on completely randomized design with three replications. After the plants establishment, drought treatments were imposed. After 40 days of applying drought treatments, kaolin was twice sprayed with 7 days interval. The leaves of plants were sampled one week after the last spraying and transferred to the laboratory and the amount of soluble sugars, proline and chlorophyll concentrations were measured. In order to analysis data, analysis two-way ANOVA were used and FLST test compared means after normality test. Statistical analysis was performed using SAS software, and Excel software was used for drawing the charts.

    Results and discussion

    The results showed that the effect of kaolin foliar application and moisture stress was significant on plant height, plant diameter, leaf area, shoot dry weight, root dry weight, root volume, RWC, chlorophyll a, chlorophyll b, total chlorophyll, proline and soluble sugar .

    Keywords: Chlorophyll contents, Morphological characteristics, Proline, Soluble sugars
  • Rasoul Asadi, Farzad HassanPour *, Mitra Mehrabani, Amin Baghizadeh, Fateme Karandish Pages 185-195
    Introduction

    In arid and semi-arid areas, water can be a limiting factor for plant growth and agricultural yields. It is an important input to agricultural production and also an essential requirement for domestic, industrial and municipal activities. Increasing population and standards of living are contributing to a steep rise in demand for fresh water. By using proper irrigation management in farm, we are able to utilize water, soil and fertilizer to produce high yield and quality products. Drip irrigation is considered one of the most efficient irrigation methods. One of the major advantages is its ability to apply water to the soil as often as desired and in smaller quantity than the other irrigation methods. Drip irrigation has been practiced for many years for its effectiveness in reducing soil surface evaporation and it has been widely used in horticultural crops in both greenhouse and open field. Also, deficit irrigation is one of the strategies for efficient use of water and increasing water use efficiency in agricultural district. Deficit irrigation is a suitable solution to gain acceptable and economic performance by using minimum amount of water.

    Materials and methods

    In order to investigate of surface and subsurface drip irrigation systems under soil matric potential on Rosmarinus officinalis L., a field experiment was carried out during 2015 growing seasons at center of seed and plant production of Kerman municipality. The treatments were laid out in randomized complete block design with three replications. The treatments were comprised of three soil matric potentials of 40, 60, and 80 centi-bar for initiation of irrigation in the main plot and sub plot consisted of two drip irrigation systems (surface and subsurface). In this study, surface systems, drip lines were placed on the soil surface at a distance of 15 cm from the plant and subsurface systems, drip lines were placed at a depth of 30 cm. The irrigation time was determined based on the readings of metal Tensimeters. These tensiometers were installed in three depths of 15, 30 and 50 cm of soil and at a distance of 20 cm from the plant. In this regard, in both irrigation systems, a Tensiometer mounted at a depth of 15 cm of soil was used for early growth and growth development, and from Tensiometers mounted at depths of 30 and 50 cm soil, for reading in the middle and final stages of growth. In order to carry out irrigation at the potential point of view, the tensiometers were fully controlled and when the calibrated tensiometer screen showed the desired potential point, irrigation was carried out and the irrigation process continued until the soil moisture reached the crop capacity level. Dry weight, leaf area index (LAI), number of shoots, plant height, water productivity were measured. Data were analysed statistically using SAS Statistical software. Treatment means were compared using LSD test.

    Results and discussion

    The results showed that in comparison to 40 and 60 c-bar tension, parsimony of water usage equal 44.6 mm (21.7 percent) achieved. Moreover dry weight, number of shoots per plant and height of plant decreased 12.5, 12.8 and 11 percent respectively but water use efficiency increased 10.5 percent. Moreover dry weight in subsurface drip irrigation was increased 48 gr.m2 compared with surface irrigation. Also parsimony of water usage equal 10 percent and water use efficiency increased 21.4 percent. Number of shoots per plant and height of plant increased 8.2 and 8.7 percent respectively in subsurface drip irrigation.

    Conclusion

    According to the results, for Rosmarinus officinalis L. cultivation in Kerman area, application of the 60 centi-bar of soil matric potentials in subsurface drip irrigation system is the best way to increase the water use efficiency for the drought years.

    Keywords: Drought stress, Kerman, Leaf area index, Soil Potential, Surface, Subsurface Drip Irrigation
  • Mohammad Dashtaki *, MohammadReza Bihamta, Eslam Majidi, Reza Azizinezhad Pages 197-210
    Introduction

    Wheat is a major crop among cereals and plays a critical role in the national economy of developing countries. In Iran, grain yield of wheat reduced by terminal drought stress. Drought stress is one of the most important factors limiting the growth and yield of crops such as wheat as the most important crop in arid and semi-arid regions of the world as well as in Iran. It is growing in a wide range of climatic conditions and plays an important role in Supplying human food needs. This plant is exposed to drought stress at the germination stage and the end of the growth season. Genotypes that can react to drought stress at the germination stage have a better growth in seedlings. The aims of this research is to Investigate the response of the germination components to different levels of drought stress in bread wheat genotypes and also finding drought tolerant genotypes.

    Materials and methods

    This research was conducted to study of drought stress treatments on seed characteristics and seedling growth of wheat Thirty wheat genotypes including Mihan, Aroom, Navid, Alvand, Zarrin, Zare, Sison, Alamoot, Gascogen, Heydari, Rizhav, Baran, Karim, Koohdasht, Pishgam, Star, Pishtaz, Qods, Marvdasht, Sardari, Kavir, Dez, Virinak, Alborz, Hirmand, Roshan, Zagros, Bezostaya, Azar and Sirvan. For this propose, a factorial experiment was conducted using 4 levels of osmotic potential (0, -4, -8, -12, -16 bar) using poly ethylene glycol. Seeds were sown on laboratory and data were recorded and analyzed for percent and speed of germination, length of root and shoot, vigor index and fresh and dry weight of seedling. Data analysis was carried out using SAS (Statistical Analysis System ver 9.1), MSTAT-C, SPSS 18 and means were compared using by Duncan's multiple range tests (P< 0.05).

    Results and discussion

    In agreement with other studies, drought stress condition significantly decreased All Germination traits with increasing levels of stress. The results showed significant differences among genotypes, drought stresses and genotypes × drought stress interaction for most of traits. In this study, 30 wheat genotypes were exposed to drought stress at flowering stage. The genotype Heidari had higher performance for length of root and percent and speed of germination whereas Azar genotype was the worse. Genotype Sardari had higher performance for seedling vigor index and length of shoot whereas Azar genotype was the worse. Genotype Roshan had higher performance for fresh and dry weight of seedling, while Alvand genotype was the worse. The results in control condition was showed that length of root had the highest positive and significant correlation with percent and speed of germination and germination index and under drought stress condition between all of traits were positive and significant correlation. According to principal component analysis, two main components were selected that in total 72 percent of the total variation was explained.Factors analysis was performed using the studied traits, and two factors( based on specific values larger than one) justify about 72% of the variations in the total data, of which the first factor justifies about 53% of the variations, including traits Root length, stem length, percentage and speed of germination, seed index and germination index, and the second factor, which justifies about 19% of the variation, includes somewhat two traits and seedling dry and fresh weight. Therefore, selection based on these two factors showed the most effect on germination of seeds. In order to determine the variation between different genotypes of different types and determine the relationship between genotypes, cluster analysis using Ward method was performed based on 8 indicators and component of the study. Genetic types of wheat were grouped in 4 clusters with similar intra-group characteristics and non-similar groups. It indicated that 9 genotypes in the first cluster, 14 genotypes in the second cluster, 6 genotypes in the third cluster and Karim genotype were placed alone in the fourth cluster. Information contained in each cluster Groups have led to the identification of genotypes with unique traits and will help us select parental cross-breeds.The fourth cluster (including Karim genotype) had the highest mean and deviation from the mean for root length, percentage and speed of germination, seedling fresh weight and germination index. The third cluster included six genotypes such as Rijaw, Starr, Ghods, Marvdasht, Sardari And bright in terms of stem length, vigor index and seedling dry weight had the highest mean. It can also be argued that the Karim and Heidari genotypes can be used for cross-breeding programs in two separate clusters and maximum genetic distance between them.

    Keywords: Drought stress, Genotype, Germination percentage, Seed germination, Wheat
  • Saied GhavamSaeidiNoghbi, Mostafa Yaghoobzadeh, Ali Shahidi, Hossein Hammami * Pages 211-223
    Introduction

    Due to the presence of Iran in the arid and semi-arid regions of the world, drought and salinity are environmental stresses known as main factors that led to reduce the production of crops in Iran. Drought and salinity are major abiotic stresses that adversely affect crop productivity and quality. Their harmful effects are increasing due to global warming, and human activities such as overutilization of water resources, over-irrigation, and improper drainage, besides natural causes such as high evaporation rates in arid and semi-arid regions that led to decrease available water and increase salt accumulation in this sites. Drought and salinity have osmotic, ionic and nutritional constraint effects on plants. These effects lead to disturb photosynthetic path, growth retardation, metabolic disturbances and oxidative stress. Usually, these stresses happened at the same time especially in arid and semi-arid regions. Therefore, this study was conducted for determination growth and yield response of wheat to drought and salinity happened at the same time.

    Materials and methods

    In order to evaluate the response of unfarm 4 wheat cultivar to different irrigation water and salinity levels, a factorial experiment based on a completely randomized block design with three replications was conducted at research field of agriculture, University of Birjand in 2016-2017. The treatments consisted of different levels of irrigation (I1, I2, I3 and I4, respectively 125, 100, 75 and 50% of plant water requirement and I5 including rain fed with one supplementary irrigation) and two levels of irrigation water salinity (non-saline (S1=1.4 dS.m-1) and Saline (S2= 5.4 dS.m-1) water, respectively). The studied traits included plant height, leaf area, spike length, 1000-seed weight, plant fresh weight, plant dry weight, number of seeds per spike, spike length, biological yield, grain yield, and harvest index.

    Results and discussion

    The results of analysis of variance showed that the significant effect of different levels of irrigation at 0.1% level on all traits including plant height, leaf area, 1000-seed weight, fresh weight of plant, plant dry weight, spike length, number of seeds per spike , biological yield, economic performance and harvest index are (Table 3). In agreement with results of this study Wajid et al., (2002) reported that improvement of wheat yield with increasing irrigation levels. Plant height, 1000-seed weight, grain yield, and harvest index of wheat (Varamin cultivar) were significantly affected by irrigation levels (Eidizadeh et al., 2016). Soleimani (2016) also reported that the yield and yield components of wheat (in the climate of Isfahan) were strongly influenced by different levels of irrigation. The effect of irrigation water salinity was significant at 1% on plant height, leaf area and 1000-seed weight, but its effect on fresh weight of plant, plant dry weight, spike length, number of seeds per spike, biological yield, economic yield, and harvest index was not significant (Table 3). Irrigation water salinity on yield and yield components of different wheat cultivars including Chamran, Sistan, Hajiabad, Parsi, Yavarus, Behrang, U. 520, S-83-3, D-81-18 showed a significant decrease depending on variety. Interaction between irrigation and salinity levels of irrigation water showed a non-significant effect on the leaf area, spike length, and grain yield. The results of this study revealed that the highest and lowest value for different traits was observed at 125% plant water requirement and rain fed with one supplementary, respectively where the loss percent for plant height, leaf area, spike length, 1000-seed weight, plant fresh weight, plant dry weight, spike length, number of seeds per spike, biological yield, economic yield, and harvest index were 37%, 63%, 64%, 66%, 14%, 42%, 62%, 61%, 89%, and 75%, respectively. The results of Yousfi et al., (2010) showed that salinity of irrigation water at levels of 1.8, 12 and 17 dS.m-1 and irrigation at two levels of 100 and 35% of water field capacity by soil on biomass traits plant production, plant height, biomass, leaf chlorophyll and nutrient elements including nitrogen, potassium, calcium, magnesium and phosphorus had a significant effect at 1% level. Correlation results revealed that the highest correlation between grain yield and biological yield.

    Conclusions

    In general, the results of this experiment showed that reduction of irrigation levels (percent plant requirement) leads to reduction of growth and yield characteristics of wheat. Irrigation water salinity was significant decrease at 5.4 dS.m-1 level on plant height, leaf area and 1000-seed weight. Interaction between irrigation and salinity levels of irrigation water showed a non-significant effect on the leaf area, spike length, and grain yield. The results of this study revealed that the highest and lowest value for different traits was observed at 125% plant water requirement and rain fed with one supplementary, respectively. According to high soil salinity (Table 2), observation of the highest amount of biological yield and grain yield in 125% water requirement is acceptable due to prepare the full or partial water need for salt leaching.

    Keywords: Biological yield, Grain yield, Harvest index, Water requirement, Wheat
  • Fatemeh Noori *, Hassan Etesami, Hamid NajafiZarini, Nayer AzamKhoshkholghSima, Gholamali Ranjbar Pages 225-235
    Introduction

    Salinity stress negatively impacts agricultural yield throughout the world affecting production whether it is for subsistence or economic gain. The plant response to salinity consists of numerous processes that must function in coordination to alleviate both cellular hyperosmolarity and ion disequilibrium. In addition, crop plants must be capable of satisfactory biomass production in a saline environment (yield stability).Soil salinity is a major constraint to food production because it limits crop yield and restricts use of land previously uncultivated. The United Nation Environment Program estimates that approximately 20% of agricultural land and 50% of cropland in the world is salt-stressed Natural boundaries imposed by soil salinity also limit the caloric and the nutritional potential of agricultural production. These constraints are most acute in areas of the world where food distribution is problematic because of insufficient infrastructure or political instability. Water and soil management practices have facilitated agricultural production on soils marginalized by salinity, but additional gain by these approaches seems problematic. Salinity is one of the most brutal environmental factors limiting the productivity of crop plants because most of the crop plants are sensitive to salinity caused by high concentrations of salts in the soil, and the area of land affected by it is increasing day by day. For all important crops, average yields are only a fraction – somewhere between 20% and 50% of record yields; these losses are mostly due to drought and high soil salinity, environmental conditions which will worsen in many regions because of global climate change. A wide range of adaptations and mitigation strategies are required to cope with such impacts. Efficient resource management and crop/livestock improvement for evolving better breeds can help to overcome salinity stress. However, such strategies being long drawn and cost intensive, there is a need to develop simple and low cost biological methods for salinity stress management, which can be used on short term basis. Microorganisms could play a significant role in this respect, if we exploit their unique properties such as tolerance to saline conditions, genetic diversity, synthesis of compatible solutes, production of plant growth promoting hormones, bio-control potential, and their interaction with crop plants.

    Materials and methods

    Salinity is a major abiotic stress limiting growth and productivity of plants. Hence, the aim of this study was to investigate the effect of the plant growth promoting bacteria (isolated from alfalfa plant nodules) on reducing the effects of salinity stress in the alfalfa plant. For this purpose, 63 bacterial isolates were isolated from the nodules of 13 samples of alfalfa plants grown in the agricultural fields of Qom province. These bacterial isolates were characterized in terms of the resistance to salinity and some the plant growth promoting traits. Finally, three superior isolates including two non-rhizobial isolates A36 and A37 and one rhizobial isolate ARh29 were selected for greenhouse testing. Based on the 16S rRNA gene sequences, the isolates A36, A37, and ARh29 were closely related to Klebsiella sp., Kosakonia cowanii and Sinorhizobium meliloti, respectively. Greenhouse experiment was conducted in a completely randomized design with factorial arrangement in three replications. Salinity levels and bacterial levels included 0, 50, 100, 150, and 200 mM sodium chloride (NaCl), the isolates A36 + A37, ARh29, A36 + A37 + ARh29, negative controls (plants non-inoculated with bacterial isolates and fertilized with N-free Hoagland's solution), and positive control (plants non-inoculated with bacterial isolates and fertilized with N- containing Hoagland's solution plants), respectively.

    Results and discussion

    The results showed that bacterial strains could increase plant dry weight and proline content in all salinity levels compared to non-inoculated plants. In addition, bacterial strains increased the uptake of potassium ions and decreased the absorption of sodium ions in alfalfa plants under salinity stress. At salinity level of 200 mM NaCl, plant dry weight and proline content in the plants inoculated with every three bacterial isolates were respectively 29 and 35% more than those in the positive control plants and the ratio of potassium to sodium was 36% higher than this control. In general, the results of this study showed that alfalfa plant root nodules harbor salinity tolerant-and plant growth promoting non-rhizobial bacteria and that their use along with rhizobial bacteria can improve alfalfa plant growth under salinity stress.

    Keywords: Klebsiella sp, Kosakonia cowanii, Nitrogen fixation, Non-rhizobial bacteria, Rhizobial bacteria
  • Mahmood Dejam, Majid Rajaie *, Shima Johari, Sirus Tahmasebi Pages 237-250
    Introduction

    Salinity stress is one of the limiting factors in crop production especially in agricultural lands of arid and semi-arid regions. Under salinity stress, the availability of nutrients is reduced due to poor soil conditions. In contrast, the use of these elements by foliar spray is an appropriate method to increase the efficiency of nutrients absorption. Application of some elements by foliar spray reduces the negative effects of salinity. According to the reports regarding the positive effects of nitrogen, calcium and potassium as inducers of salt tolerance, this study was designed to investigate the response of cumin plant in hydroponic conditions to salinity stress and foliar spray of the above mentioned elements.

    Material and methods

    This research was conducted in 1395 in a research greenhouse in Fasa, Iran. A factorial experiment was conducted in a completely randomized design with three replications. The first factor was salinity stress in three levels including control (semi Hoagland solution), semi Hoagland solution + 75 mM sodium chloride and semi Hoagland solution + 150 mM sodium chloride. The second factor was foliar spray treatments consisted of control (distilled water), calcium nitrate, potassium nitrate, ammonium nitrate and calcium nitrate + potassium nitrate which were prepared with concentrations of 5/857, 7.214 and 2.857 kg per 1000 liters of water, respectively. These concentrations were selected in such a way that the nitrogen concentration used in all of them was equal. Salinity treatments were applied to Hoagland solution. Spraying of the desired compounds was carried out every two weeks until the end of the flowering stage.

    Results and discussion

    The results showed that increasing in salinity stress reduced plant dry weight and leaves chlorophyll content in cumin. Foliar spray of calcium nitrate + potassium nitrate and calcium nitrate alone could somehow prevent the adverse effects of salinity on cumin. Compared to control, salinity level of 75 mM did not reduce the leaf relative water content in cumin. But increasing the salt stress to 150 mM reduced the relative water content of the leaves. While increase in salinity stress increased ion leakage, compared to control foliar spray of calcium nitrate, potassium nitrate, ammonium nitrate and calcium nitrate + potassium nitrate could reduce ion leakage in cumin. At salinity level of 75 mM sodium chloride, foliar spray of calcium, potassium and ammonium and at 150 mM sodium chloride, calcium spray could somewhat neutralize the adverse effects of salinity stress on chlorophyll a. The results showed that salt stress increased the sodium content of the cumin shoot. In fact, salinity stress disturbs the cationic balance of cumin and prevents the absorption nutrient elements and provides the possibility of more sodium absorption by cumin. In all salinity treatments, compared to control, foliar spray of the utilized compounds increased the number of umbel per plant. Calcium and potassium sprays with a competitive effect reduced the sodium absorption and to some extent could play a role in improving the yield components of cumin.

    Conclusions

    Overall, the results of this study showed that increase in salt stress caused disturbance in leaf relative water content, ion leakage and chlorophyll content of cumin. However, foliar spray of calcium nitrate and potassium nitrate increased leaf relative water content and reduced ion leakage in cumin. Also, increase in salt stress caused a disturbance in cationic balance and prevented other cations such as calcium, potassium and magnesium to be absorbed while allowed cumin to absorb more sodium. Finally, the use of various spray combinations could improve the number of umbrellas per plant, the number of seeds per umbrella and the weight of 1,000 seeds of cumin in 75 mM salt stress conditions.

    Keywords: Calcium, Ion leakage, Leaf relative water content, Thousand grain weight
  • Jalal Khorshidi * Pages 251-261
    Introduction

    salinity stress is one of the most important abiotic stresses limiting plant cultivation. Evaluation of germination characteristics under salinity stress conditions is one of the fastest methods for selecting resistant plants to this stress.

    Materials and Methods

    Ocimum basilicum L. (Basil), Thymus daenensis Celak. (Denaee thyme), Hyssopus officinalis L (Hyssop). And Dracocephalum moldavica L. (Moldavian balm) seeds were subjected under six salinity treatments (0, 3, 7, 10, 15 and 20 ds/m) in growth chamber with daily mean temperature 25 °C, night mean temperature 18 °C, day length 14 hours and night length 10 hours. After germination (emergance of 2mm root),were evaluated germination characteristics such as seedling fresh weight, fresh weight of radicle and shoot, ratio of shoot/ radicle weight, seedling length, length of radicle and shoot, ratio of shoot/ radicle weight, germination percentage, seed vigor index, germination rate, mean of germination time and tolerance index. Experiment was conducted as factorial based on completely randomized design with three replicates at research center of medicinal plants breeding and development, university of Kurdistan in 2018.

    Results and discussion

    seeds of these plants were unable to germinate at salinity level of 10 ds/m or more. Mean of germination time, seedling weight and shoot weight in all of plants were significantly affected by salinity, but in other characteristics, effect of salinity was different depend on plant species. Germination rate decreased in all plants with increasing level of salinity. Basil and Moldavian balm seeds required the lowest and the highest time for germination, respectively. Seed vigor index similar to germination rate decreased with increasing level of salinity. The highest of seedling weight, shoot weight and radicle weight in all studied plants was observed in salinity level of 3 ds/m. It seems that increasing in weight at low level of salinity can be due to existence and efficacy of Na and Cl ions on membrane penetrability and also enzyme activity relevant to germination that finally will be led to increase in growth rate and seedling weight, but in continue with increasing salinity level and further decreasing of osmotic potential, division, turgescence and cell volume decrease and eventually weight loss in the seedling will be seen. Seedling weight of Basil, Hyssop and Moldavian balm decreased with increasing level of salinity, but seedling weight in Denaee thyme increased at first and then decreased with increasing in salinity level from salinity level of 3 to 7 ds/m. Seeds germination percentage of Denaee thyme, Moldavian balm and Hyssop decreased significantly with increasing level of salinity and in all of three mentioned plants, germination stopped in salinity level of 10 ds/m. But in Basil against to other plants, germination percentage increased with increasing level of salinity up to salinity level of 7 ds/m and then germination reach to zero with increasing in salinity level from 7 to 10 ds/m. The highest tolerance to salinity level of 3 ds/m was observed in Basil, Moldavian balm, Hyssop and Denaee thyme seedling respectively and the highest tolerance in salinity level of 7 ds/m was observed in Basil, Moldavian balm, Denaee thyme and Hyssop seedling, respectively. Whereas with increasing in salinity level, osmotic potential of water will be decreased, therefore water absorption by seed will be decreased and subsequently rate of metabolic activates in seed such as carbohydrates hydrolysis and breaking will be decreased and therefore germination characteristics such as percentage and rate of germination and also length of root and length of shoot will be reduced.

    Conclusions

    Generally, based on results of this research, it has been suggested that salinity had not unfavorable effects on germination until special level and even same to basil can be improved germination characteristics. But, if salinity be upper than tolerance threshold of plant, can lead to undesirable effects on germination characteristics. Tolerance threshold to salinity stress is varying in different plants and as the results showed, the highest and the lowest of tolerance threshold was related to basil and Hyssop, respectively.

    Keywords: Germination percentage, Seed vigor index, Tolerance index, NaCl
  • Alireza Borjian Boroujeni *, Abdolmahdi Bakhshandeh, SeyedAtaollah Siadat, Khalil AlamiSaeid, Mohamadreza JalalKamali Pages 263-271
    Introduction

    Short periods of heat stress in spring under Mediterranean climate (e.g. southern vast areas of Iran) are common and cereal crops often exposed to short periods of elevated temperatures which can have large effects on crop yields. Stem water-soluble carbohydrate (WSC) could be an important carbon bank for supporting grain filling in wheat especially when carbon assimilation is hampered by heat stress. In Iran, a large number of studies have been done on the effects of heat stress on grain yield of wheat and its components, based mainly on the change in planting date, and data from the effect of short-term heat wave on yield and grain growth and the role of WSC in developing grains do not exist under field conditions. The aim of this study was to determine the effects of short-term heat stress before flowering and the beginning of grain filling on peduncle WSC and grain filling pattern as well as determination of the contribution of peduncle WSC in genotypes with different amounts of carbohydrates in grain growth under short-term stress conditions.

    Materials and methods

    This research was carried out 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). to investigate the changes in individual grain weight (IGW) during grain development, the total WSC changes in the peduncle of the main stem after exposure to short-term heat stress during the development of grain, three plants marked from day zero after flowering. The grains were harvested at intervals of seven days until the time of maturity. The total WSC were measured by anthrone method. When the dry weight of peduncles was maximized in each genotype, the concentration of peduncle carbohydrates (WSC-C) was considered as the maximum WSC-C. To calculate the maximum peduncle WSC content, the maximum WSC-C was multiplied by the maximum peduncle weight. The difference between peduncle WSC-C at maximum time and at maturity time was considered as the mobilized WSC from peduncle to grain. The ratio (%) of peduncle mobilized WSC to maximum peduncle WSC-C was calculated as the efficiency of peduncle in mobilized WSC. The analysis of variance of the measured traits in this study was performed using SAS 9.4 software. Duncan's test was done for means comparison.

    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) caused a significant reduction in individual grain weight (IGW) and grain number of main spike. There was no detectable change in IGW until 14 days post-anthesis, after which time grain growth in the heat-stressed plants was reduced from 4.5% to 17%. Based on number of grain per spike and IGW, Atrak, Chamran and Arvand genotypes were recognized as tolerant gynotypes. Heat stress (average of H1 and H2) reduced maximum peduncle water soluble carbohydrate (WSC) content by 26% and mobilized WSC by 15%. The reduction of peduncle WSC content by the heat stress treatments appeared to start at 21 days post-anthesis Reductions in IGW and among genotypes were negatively correlated to the maximum peduncle WSC content.

    Keywords: Grain weight, Heat, Peduncle, Soluble carbohydrates
  • Hossein Kamaei *, HamidReza Eisvand, Mashaallah Daneshvar, Farhad Nazarian Pages 273-283
    Introduction

    Wheat (Triticum aestivum L.) is one of the most important sources of plant food for human among the main crops globally. High temperature resulting from delay in planting is one major environmental factor limiting growth and production of wheat, especially in tropical regions. Terminal heat stress during the last phases of wheat development especially in booting, heading, anthesis and grain filling stages of the spring wheat cultivars is considered as one of the major environmental constraints that drastically reduces grain yield and yield components of wheat in Khuzestan province and other warm and dry regions of Iran. Most of the Iranian soils have a high pH and calcareous nature, so absorption of nutrients is limited in these soils. Mineral nutrition of plants plays a critical role in increasing plant resistance to environmental stresses. 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. Boron is essential for pollen viability, flowering, fruiting and seed production. As a micronutrient, it plays a vital role in nitrogen metabolism, hormonal action, and cell division.

    Materials and Methods

    To evaluate the remobilization of photosynthetic materials and their contribution in the formation of grain yield of two bread wheat cultivars affected by terminal heat stress and zinc and boron foliar application, an experiment was conducted as split-split plot based on randomized complete blocks design with 3 replications in Ramhormoz city. The experimental factors were included planting date in two levels optimum (November 21) and late (January 5) to coincide growth terminal stages with high temperatures as the main factor, foliar application in four levels with water (control), zinc, boron and zinc + boron as the sub factor and two cultivars of bread wheat Pishtaz and Chamran 2 as the sub-sub factor.

    Results and discussion

    The results showed that terminal heat stress caused by delay in planting increased significantly traits of stored photosynthetic materials remobilization from stem and spike to seed and relative contribution of stem and spike reserves in grain yield, but decreased significantly traits of current photosynthesis and its relative contribution in yield, and grain yield of two bread wheat cultivars of Pishtaz and Chamran. Zinc and boron foliar application reduced significantly all of the above traits in both optimum and late planting dates except for the traits of current photosynthesis and its relative contribution in yield, and grain yield. Among the wheat cultivars cultivated, Chamran 2 cultivar had a significant advantage in traits of current photosynthesis and current photosynthesis relative contribution in yield and grain yield compared to Pishtaz cultivar, but in other traits this superiority was evident in Pishtaz cultivar.

    Conclusions

    In general, it can be attributed the main factor increasing grain yield of two bread wheat cultivars of Pishtaz and Chamran to improve current photosynthesis. As well as, it can be used from timely planting date, zinc and boron foliar application and suitable wheat cultivar such as Chamran 2 as three management strategies to reduce the harmful effects of terminal heat stress caused by late planting date in Ramhormoz city.

    Keywords: Current photosynthesis, Micro elements, Planting date, Wheat cultivars
  • Hossein Kamaei *, HamidReza Eisvand Pages 285-295
    Introduction

    Wheat (Triticum aestivum L.) is considered as the major cereal crop in the world in respect of the cultivated area and total production. High temperature resulting from delay in planting is one major environmental factor limiting growth and production of wheat, especially in tropical regions. 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 iron, zinc and manganese foliar application on the physiological, agronomic traits and protein of wheat under late season heat stress, 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 planting date in two levels (5 November and 20 December) 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 delay in planting due to terminal heat 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, iron, zinc and manganese foliar application could increase significantly the measured traits in optimum and late planting date. Meanwhile, application of zinc spray showed the greatest effect in reducing the damage caused by terminal heat stress on measured traits.

    Conclusions

    In general, planting on 5 November and the use of micronutrients, especially zinc, as foliar application, can reduce the harmful effects caused by terminal heat stress and improve the physiological, agronomic traits and grain protein content of bread wheat in the region.

    Keywords: micronutrients, Planting date, Wheat
  • Leila Fahmideh *, AliAsghar Ghaderi, Ayoub Mazaraie, Amir Rajabi Pages 297-312
    Background

    Basil (Ocimum basilicum), a member of Lamiaceae family, is used in traditional Iranian medicine. Essential oils of basil leaves are composed of phenylpropanoids which are important in treatment of headaches, diarrhea, coughs, warts, worms and kidney malfunctions. The most important phenylpropanoid compounds contain eugenol, chavicol, methyl eugenol, methyl chavicol, myristicin, methyl cinnamat and elemicin. Heavy metals pollution is a major problem of crops and medicinal plants production inthe large parts of the world which has a negative impact on all aspects of plant growth and production. Heavy metal toxicity is one of the major current environmental health problems and potential dangerous due to bioaccumulation through the food chain and in plant products for human consumption. Arsenic is a heavy metal with high toxicity that absorbed by plants mainly through the root system and in minor amounts through the leaves. After entering the cells, lead inhibits activities of many enzymes, and affects membrane structure and permeability. Today, phenolic compounds and plant growth regulator has been proposed, to reduce the negative effects of stress. Salicylic acid is a substance that causes plant resistance to biotic and abiotic stresses. Salicylic aside inhibit the production of reactive oxygen species and protect plants against ROS damages. This study was to evaluate the effect of Salicylic aside spray on some morphological characteristics, photosynthetic pigments activities of antioxidant enzymes basil was conducted under arsenic stress.

    Materials and methods

    This study was conducted at the Faculty of Agriculture, University of Zabol a factorial in a completely randomized design with three replications. The experimental treatments was included arsenic stress 0 (control), 10, 45 and 80 mg per kg of soil and application of salicylic acid at 3 levels of 0, 1 and 2 mM. T. Physiological traits (Chlorophyll a, b and T. chlorophyll, Carbohydrate, Carotenoid), morphological characteristics (fresh and dry weight, leaf area) and activities of antioxidant enzymes (Peroxidase and Catalase) were estimated in this experiment. The statistical analyses were carried out using the SAS version 9. The treatment means separated using Duncan's multiple-range test (DMRT) taking P < 0.05 as significant.

    Results

    Based on the results, increasing of stress severity reduced some traits, So that addition of 80 mg per kg of soil arsenic significantly reduced amount of fresh and dry weight, leaf area , chloroohyll a, b and total, carotenoid and increased concentrations of carbohydrate and anti-oxidant enzyme (catalase and peroxidase ). Also, the results of simple effects of foliar application levels showed that by increasing the concentration of foliar application, the traits were increased, so that The highest fresh and dry weight, leaf area , chloroohyll a, b and total, carotenoid and carbohydrate was obtained in plants spraying with 2 mM SA, But reduced the activity of the antioxidant compounds. on the other hand, In this study the interaction between salicylic acid and arsenic on chloroohyll a, b, total and anti-oxidant enzyme catalase and peroxidase were significant, so that the highest of amount of chloroohyll a, b and total, were obtained in plants subtended in sprayed with 2 mM SA and without stress, But the highest the activity of the antioxidant enzyme catalase and peroxidase were obtained in plants Under in stress 80 mg per kg of soil arsenic and without sprayed.

    Conclusion

    Our observations indicated that ascorbic acid spraying at lower concentration might be favorable to improve growth and defense ability against arsenic toxicity in basil though field testing would be required to verify this and Based on the findings of this study, as well as supplemental studies, salicylic acid spraying can be proposed to improve the growth and reduce the arsenic toxicity of Basil plant under arsenic stress.

    Keywords: Heavy metals stress, Medicinal plant, Salicylic acid, Spraying
  • Mehdi Karimi *, Babak Khayyambashi, Seyyedalimohammad Cheraghi, Majid Nikkhah, MohammadHassan Rahimian, Hadi PirastehAnosheh, Mehdi Shirantafti, Vali Soltanigerdefaramarzi Pages 317-322
    Introduction

    Salinity stress is known as a worldwide plant growth limiting factors (Alavimatin et al., 2015: Atlasipak 2018). In addition, it is estimated that around 50 percent of arable lands are affected by salinity stress by 2050 (Butcher et al., 2016: Qadir et al., 2014). The use of chemical fertilizers is a common practice in arid soils for improving plant performance grown under non-fertile soils. While there is little evidence of yield benefits due to application of fertilizers in salt affected soils at rates beyond optimal in non-saline conditions, there is enough evidence indicating that soil salinity does not affect or decrease plant fertilizer requirements (Hanson, 2006). Accordingly, the objectives of this field study were to (a) evaluate the interactions between phosphorous nutrition and the salinity of irrigation water and their effects on wheat growth and (b) test the possibility of wheat improvement at saline conditions by applying higher levels of phosphorous fertilizer.

    Materials and methods

    A field experiment was conducted on wheat at Sadooq Salinity Research Station, Ashkezar, Yazd, Iran. The soil at the experimental site was calcareous with 30.92% total nutrient value, sandy loam texture, pH 8.06 and 0.22 % organic carbon. Mean annual temperatue is 18°C and precipitation is 70 mm. The treatments, four triple superphosphate application rates (0, 100, 200 and 300 kg ha-1) and three irrigation water qualities (1.88, 7.22 , 14.16 dS/m), arranged in a randomized block with three replications. Consisting 12 rows of wheat, each field plot was 3*5 m. All plots received common agricultural practices including tillage and fertilizer application. Rgarding typical recommendations and guidelines for this region and soil type (Balali et al., 2000: Moshiri et al., 2015), all fertilizers, except urea that applied in 4 splits, were soil-applied before planting and included 40 kg ha-1 ZnSO4, 40 kg ha-1 MnSO4 and 20 kg ha-1 CuSO4. To model the relationship between plant properties and irrigation water salinity, the data were subjected to different regression models at the probability level of 0.01 and 0.05 with the help of the Sigmaplot software. The analysis of variance for different parameters was done following ANOVA technique. When F was significant at p ≤ 0.05 level, treatment means were separated using LSD.

    Results and discussion

    The results showed that increasing irrigation water salinity to 7.22 dS/m did not significantly affect wheat grain yield. This is due to the positive effect of salinity on 1000 seed weight and harvesting index. At the same time, the results showed 50% decrease in wheat grain and straw yield due to the increase in the salinity of irrigation water from 1.88 to 14.16 dS/m. The heighest graine yield for treatments irrigated with irrigation water salinity of 1.88, 7.22 and 14.16 dS/m was obtained from application of 40, 20 and 0 kgha-1 FeSO4, respectively.

    Conclusion

    Overall, it was concluded that application of triple superphosphate at a rate of 150 kgha-1 is recommended for wheat yield improvement at irrigation water salinity of 1.88 and 7.22 dS/m. As wheat performance irrigated with irrigation water salinity of 16.14 ds/m was not affected by different rates of phosphorous fertilizer, it can be concluded that wheat phosphorous requirement decreased at irrigation water salinity beyond salt tolerance.

    Keywords: Irrigation water, Triple superphosphate, and Salinity