مجله علوم گیاهان زراعی ایران
سال پنجاه و یکم شماره 1 (بهار 1399)

Expansins are non-enzymatic proteins in the cell wall, which are the main factor for cell elongation.The flexibility of the plant cell wall is regulated by acidification and activation of expansins. In this study, the effects of transferred AtEXPA18 gene on transgenic tobacco plants were investigated. To confirm the transgenic plant, RNA was extracted from the plant leaf sample and then cDNA was synthesized. After that PCR was done via a specific primer of the AtEXPA18 gene. Seeds were cultured in selective MS medium containing kanamycin. Transgenic seedlings tolerate medium which contains kanamycin and Non-transgenic seedlings got white and died. Subsequently, some of these seedlings were grown in the greenhouse and others were grown in Hoagland nutrient solution for evaluating root morphology. Greenhouse studies showed that the transgenic plants were better than non-transgenic plants in some traits such as seed weight, capsule weight, and 100 seed weight. Transgenic plants grown in Hoagland were better than non-transgenic plants in some other traits like shoot and root dry weight, and root length. Consequently, L4 transgenic line had the best performance among transgenic lines.

A field experiment was conducted to evaluate the effect of mulch and planting date in integrating with herbicide application for weed control in lentil. The experiment was in a split-split plot arrangement with three replication at the research farm of University of Tehran in fall of 2016 and spring of 2017. The spring and fall planting dates were main plots, mulch types (secale, barley, no mulch (Control)), and herbicides (trifluralin, imazethapyr, pyridate) were assigned to subplots and sub-sub plots, respectively. Galium aparine, Amaranthus retroflexus and Chenopodium album had the highest population among the weed species present in the field. The average weed population in mulches was significantly lower than bared soil. In the fall planting date, the weed biomass was averagely 40% lower than in spring planting time. In the fall planting, imazethapyr was found the most efficient herbicide, while in spring planting, pyridate and imazethapyr herbicides showed similar efficiency. Generally, fall planting date produced 50% more yield than spring planting. The treatment of secale mulch result in improved yield by 56% as compared to no mulch (control). Besides, pyridate herbicide increased the total yield by 68% as compared to control. It would be better to use the secale mulch followed by hand-weeding, if cheap working force are available. Otherwise the application of imazethapyr and secale mulch was the best option for weed control in lentil.

This experiment was conducted at Rice Research Institute of Mazandaran in 2014 & 2015 as a factorial based on randomized complete block design with three replications, the factors were nitrogen amount (40, 80, 120 and 160 kg ha-1) and splitting time application (T1: 50% basal+ 50% tillering stage); (T2: 33.33% basal + 33.33% tillering stage+ 33.33% panicle initiation stage); (T3: 25% basal+ 37.5% tillering stage+ 37.5% panicle initiation stage); (T4:25% basal + 25% in maximum tillering stage + 50% in panicle initiation). Results showed a significant effect of treatments on flag leaf all morphophysiological and evaluated traits. Also, the chlorophyll index, plant biomass, and grain yield influenced significantly by the interaction of nitrogen amount and splitting time. Most flag leaf chlorophyll index (35.9) was obtained through application of 160 kg N ha-1. Least grain yield (5490 kg ha-1) was obtained at the T1 splitting and nitrogen application of 40 kg ha-1. According to results, use of 120 kg N ha-1 with splitting time application of T3 and T4 were recommended for obtaining the best desired morphophysiological traits of flag leaf and higher yield in Shiroudi cultivar.

To investigate the storage capacity and remobilization of stem dry matter in three wheat cultivars under different moisture regimes, a factorial experiment was conducted in a randomized complete blocks design with three replications in the experiment field of the College of Agriculture and Natural Resources, University of Tehran, in 2014-2015. Treatments included three of wheat cultivars (Pishtaz, Sivand and Parsi), and 12 moisture regimes were combined (70, 90, 110 and 130 mm cumulative evaporation from class A evaporation pan in before flowering stage (30-60 Zadok’s stage) and  90, 110 and 130 mm levels of cumulative evaporation in after the flowering stage, 60-93 Zadok’s stage). The result showed that the highest amount of stem dry matter storage was related to Parsi cultivar (1046 mg/stem) and T79 moisture level, with 1070 mg /s average. However, wheat cultivars reacted differently under different moisture regimes in terms of remobilization traits and remobilization efficiency. Pishtaz cultivar under treatment of T1313 (130 mm at all stages of growth), had the highest remobilization and remobilization efficiency with mean of 476 (mg /stem) and 56% respectively, and the bottom internodes, had the highest rate of remobilization (195 mg /stem, under the moisture level T1313), than the other two internode. At the same time, under the same treatments (T1313), the Parsi cultivar, despite the highest dry matter storage in the stem, had the lowest remobilization and remobilization efficiency, with an average of 427(mg /stem) and 45%, respectively, than the two other cultivars. Combined with the higher power of the Pishtaz cultivar in the remobilization of dry matter, the highest grain yield (6850 kg/ha) was obtained in this cultivar, which can be very important in drought stress.

In order to investigate the effect of additive series intercropping of legume and cereal (the line of 2561 of broad leaf vetch and Abidar cultivar of barley) on species diversity ecological indices and weeds dominance, a field experiment was conducted in 4 × 5 factorial with three replications in the dry land conditions in the research farm of the Faculty of Agriculture, University of Lorestan in the cropping years of 2015-17. The intercropping treatments reduced numbers and total dry weight of weeds ratio in sole cropping. The best treatments in first and second year for weeds control were once-weeding and seed ratios 70:100 and 100:100 (vetch: barley) and double-weeding×70:100. The three factor interactions (year, weed and intercropping) represent the contribution of 40:100 and 70:100 with once-weeding in weed dry weight losses (17.98 and 17.16 in the first and second years, respectively). In the second year, this interaction also resulted to the lowest weed dry weights (20.82 and 20 g/m-2). The lowest species richness was belonged to once and double weeding and non-weeding treatments with 100:100 seed ratio, respectively. Also, mentioned treatments indicated the weeds were more dominance in the first year compared to the second year.

The development of crops with suitable root traits, enable them to have higher yields in soils with higher salt and limited water. The aims of this study were to determine soil water potential levels to obtain a significant root growth response and identify genotypic differences in seminal root length and root branches in response to drought stress. Three separate factorial greenhouse experiments at vegetative stage of wheat were carried out based on completely randomized design with three replications. The optimum water potential level needed to obtain a significant root growth response ranged from −7 to −8 bar. The results showed the genotypic diversity in root growth response to drought stress. Drought stress reduced root system growth such as seminal axile root length, two longest seminal axile roots, number of seminal roots and distance between the root tip and the first branch root by 19, 21, 37 and 46 % respectively, compared to control. The reduction of root growth traits of tolerant drought stress cultivars was less than sensitive ones. Genotypic variation in root growth response to drought stress indicates the suitable opportunities to improve drought tolerance through plant breeding.

Sunflower (Helianthus annuus L.) from Asteraceae family is one of the most important crops grown mainly for edible oil. Sclerotinia is one of the fungi pathogens widely distributed in sunflower farms leading to totally yield losses under the favorable environmental conditions for the pathogen. The use of resistant genotypes is potentially one of the economically useful methods for its control. In this study, the expression pattern of genes PDF1.2 (defence related gene), HaZFHD (transcription factor) and HaPP2C (effective in defence signal transduction) was investigated in sunflower susceptible (SDR19) and partially resistant (8A*/LC1064C) lines after inoculation with Sclerotinia fungal isolate A37 via Real Time PCR technique. Results revealed that the expression of studied genes has significantly increased in an earlier time in partially resistant (8A*/LC1064C) line compared to susceptible (SDR19) one. Increased expression level of studied genes proves their potential role in resistance of sunflower to Sclerotinia basal stem rot disease. The findings of this study can be useful in sunflower breeding programs for producing cultivars resistant to Sclerotinia stem rot disease.

Recognition of Eryngium caeruleum germination biology can provide the possibility of forecasting the seed dormancy and germination level in various conditions. This study was conducted as factorial experiment based on completely randomized design with three replications in the laboratory of Agronomy and Plant Breeding Department, College of Agriculture and Natural Resources, University of Tehran, to understand Eryngium caeruleum seed dormancy and response of germination thermal parameters. The experimental factors were included three levels of gibberellic acid (0, 250, 500 mg/l), six chilling time (1, 3, 5, 10, 15, 30 days) and seven temperatures (5, 10, 15, 20, 25, 30, 35°c). Germination parameters were obtained by the segmented model under the influence of gibberellic acid and chilling treatments. The results of this study showed that, the best treatment for reducing dormancy level, cardinal temperatures for germination including base, optimum and ceiling temperatures was obtained 1.81, 22.31, and 34.10°c respectively. Increasing of the chilling time and the gibberellic acid concentration from 0 to 250 mg/l, decreased the base temperature, and increased optimum temperature. Ceiling temperature, at first was increased and then decreased.

To evaluate the effects of mycorrhiza and seed priming on yield and yield components of single cross 704 hybrid of maize (Zea mays L.) under salty soil condition, combined analysis experiment was carried out with a factorial arrangement of two factors based on randomized complete block design with three replications during 2014 and 2015 in both saline (EC=7dS/m) and non-saline (EC=2.5dS/m) lands at north eastern of Khuzestan province. The first factor was seed inoculation (with and without mycorrhiza (Glomus mossea L.) inoculation) and the second factor was priming with NaCl solution, salicylic acid and tap water as well as non-primed. The results showed that seed priming and inoculation with mycorrhiza treatments had significant effects on all traits in both places in two years. In saline soil, the highest increase was observed in salicylic acid treatment, which increased the grain number in ear (30.1%), 1000-grain weight (11.1%) and grain yield (44.6%) compared to non-primed and non-inoculated. Inoculation with mycorrhiza increased the number of seeds per ear (17%), 1000-grain weight (3.4%) and grain yield (20.9%) compared to non-primed and non-inoculated. Interaction of seed priming and inoculation with mycorrhiza increased all traits. The highest increase was observed in salicylic acid priming treatments and inoculation with mycorrhiza that increased colonization percentage (93.5%), Leaf area index (23.7%), the number of seeds per ear (36.8%), 1000-grain weight (16.2%) and grain yield (58.9%) compared to non-primed and non-inoculated.

To evaluate the effect of different nutrition systems (such as organic, chemical and biologic) on quantitative and qualitative traits of three selected lines of grasspea (Lathyrus sativus L.), a field experiment was conducted at College of Agriculture, Tarbiat Modares University during 2012-2013 growing season. The Experimental treatments were arranged as factorial layout based on a randomized complete block design with three replications. The first factor was three grasspea lines (L1 (Sel.B/222), L2 (Sel.B/111) and L3 (Sel.290)) and the second factor was four nutrition system (no fertilizer (F0), 100% chemical fertilizer (F1), 100% manure (F2) and integrated fertilizer (75% manure + 25% Nitroxin (F3)), respectively. Results showed that L1 (Sel.B/222) receiving 100% chemical fertilizer produced maximum forage yield (20145.8 kg.ha-1), whereas the integrated nutrition system (75% manure + 25% Nitroxin) produced the highest dry forage yield (3005.3 kg.ha-1). Integrated nutrition system (75% manure + 25% Nitroxin) having the highest percentage of dry matter digestibility, the highest protein percentage and the lowest ADF was the superior treatment in forage quality. L1 (Sel.B/222) grasspea treatment was superior in maximizing the percentage of dry matter digestibility and minimizing the percentage of ADF. The grasspea line L3 (Sel.290) produced the highest percentage of protein. The lowest crude fiber content of grasspea forage was achieved in L3 (Sel.290) under integrated nutritional system. Thus, the combined system of L1 (Sel.B/222) and F3 (75% manure + 25% Nitroxin) is a good alternative or chemical fertilizers and could be suggested for qualified and higher forage yield of grasspea.

Salinity stress is one of the spreading problems in the paddy fields of Mazandaran Province, north of Iran. In order to develop rice cultivars with good quality and salinity tolerance, seeds of Tarom Mahali, Hasani and Anbarboo varieties of rice were irradiated with gamma ray at 200, 250 and 300 gray. After sowing the irradiated seeds, 22000 panicles were selected in 2011. In 2012, the selected panicles along with check varieties, namely Tarom Mahali, Hasani and Anbarboo, were planted at a saline field in Bahnamier, Mazandaran, with a soil salinity of 4-6 ds/m, 15 seedlings per mutant. Selection of M2 mutants, based on yied, early- maturity, panicle type and plant height, resulted in 430 selected M2 mutants in 2012. 134 of M3 mutants were selected using the same criteria. In 2014, the selected M3 mutants along with check varieties were planted in a saline field at Juibar, Mazandaran under an augmented block design. At flowering stage, plant height, number of panicles per hill, and days to 50% of flowering were recorded. At maturity stage, ten panicles were randomly harvested from each plot and yield components were measured. In that year, based on agronomical characteristics, 30 lines were selected. In 2015, selected lines were planted with four replications as a randomized complete blocks design. Two mutants, namely 3214 and 3215 had the highest salinity tolerance. One to few panicles were harvested from 15 other mutants

This study was conducted to predict alfalfa forage yield based on some climatic, soil and vegetative indices (PVI) derived from Sentinel-2 sensor in Sarayan (Southern Khorasan) of Iran in July 2018. Alfalfa yield data were collected from 52 points (10 of those experimental points) in two consecutive harvests to predict alfalfa performance, a stepwise multivariate linear regression was used. Results showed that the alfalfa performance map, in both consecutive harvests, with the mean of rainfall, PVI index and soil class was significant at 1% probability level. Validation showed that R2, RMSE and GMER were 0.82, 0.88 and 0.91, respectively, indicating the high compliance of the estimated performance model with the actual yield of alfalfa. Also, the results of chi-square test (P = 0.99) showed non-significant difference between actual values and estimated hay yield during two harvests. Therefore, due to the high reliability of terrestrial observations and climatic data in the region, these variables can be used to provide proper utilization pattern for forage plants.

To investigate the effect of antitranspirants on some physiological characteristics of wheat such as photosynthesis and total chlorophyll content (chlorophyll a and chlorophyll b), percent of seed protein, seed yield, transpiration rate, and photosynthetic water use efficiency under drought stress, a split plot experiment was conducted in randomized complete block design with three replications during 2015-2016 at Miandoab Agriculture Research Station, West Azarbaijan. Irrigation factors (complete irrigation, irrigation withholding at heading stages and flowering stages) were main plots and foliar applications of antitranspirants (Prometrin, Kaolin, Tmatrom, Chitosan and control) and two cultivars of wheat (Zarin and Mihan) were sub plots. Results showed that prometrin treatment in irrigation withholding at flowering stage increased photosynthesis at 2 μmol Co2 m-2 s-1 compared to control. The highest total chlorophyll content (4.69 µg/g FW) was belonged to foliar application of chitosan at irrigation withholding at heading stage and the highest chlorophyll a was observed at chitosan treatment (2.42 µg/g FW). Foliar application of chitosan in Zarin cultivar at irrigation withholding at heading stage treatment had the highest chlorophyll b content. Chitosan treatment had the highest protein content at the irrigation withholding at flowering stage (12.27 mg/g DW) and increased yield by 868 kg/ha compared to control in Mihan cultivar. The lowest transpiration rate was obtained at irrigation withholding stage (3.83 mM H2O m-2 s-1). The results showed that the effects can be variable depending on the time of stress and the type of cultivar, Antitranspirants, especially chitosan, could improve the photosynthetic properties of wheat (Mihan cultivar) and seed yield under drought stress condition.

In temperate regions such as Iran, freezing stress tolerance is one of the plants success factors in autumn planting. So, evaluation the crops and their common weeds tolerance to the freezing will provide information about their competitive ability in these conditions, and appropriate information on weeds management. For this purpose, a greenhouse experiment was conducted in autumn 2017 in Faculty of Agriculture, Ferdowsi University of Mashhad. Wheat (Pishgam cultivar and Ghezel khoushe landrace) and wild barley and feral rye weeds were grown up to the two leaves stage in natural conditions and then, were exposed to cold and freezing temperatures (+4, 0, -4, -8, -12, -16 and -20oC). Results showed that the percentage of electrolyte leakage began to increase by temperature reduction from -8°C to -20°C and reached to its maximum. While all plants maintained their 100% survival to -12°C, wild barley had a 36% reduction in survival at this temperature. The higher LT50su in wild barley and therefore the faster survival reduction confirmed its more sensitivity to freezing temperature than other plants. At -12 °C, wild barley dry weight had higher dry weight reduction declined compared to other plants that due to high RDMT50, this plant showed more sensitivity to freezing temperatures while feral rye and Pishgam cultivar and wheat Ghezel khoushe landrace of wheat had less RDMT50, indicating the high competitive ability of feral rye in freezing conditions. There was negative and significant correlation between electrolyte leakage and survival percentage and also survival percentage and LT50su (r= -0.93* and r=-0.99** respectively). Therefore, according to the results of the present experiment, weed management priority in cold climate areas is feral rye.

To determine the traits affecting oil and protein yield and selection of suitable sesame cultivars under inoculum conditions and lack of inoculation with mycorhizal fungi and different levels of irrigation, an experiment was conducted as factorial-split plot design with three replications in research farm of Agricultural Research Center (Saatloo station of Urmia) during 2015 -2016 cropping seasons. The main plots consisted of factor A: three different levels of irrigations (normal irrigation: irrigation after 70 mm evaporation of crop or ETc, moderate drought stress: irrigation after 90 mm ETc and severe drought stress: irrigation after 110 mm ETc) and factor B: three levels of inoculation: two kinds of mycorrhizal fungi Glomus mosseae, Glomus intraradices and non-inoculated (control). Sub plots (factor C) consisted of eight commercial cultivars of sesame. In stepwise regression analysis, regarding oil and protein yield as response variables, in addition to grain yield and oil percentage and protein percentage, different traits were introduced under different conditions of mycorrhiza and water stress conditions. In path analysis (traits entered on the model included seed yield, oil percentage, seeds per square, protein percentage, capsules per plant, seeds per capsule, biological yield, protein yield, 1000-seed weight, oil yield, number of branches, plant height, stem diameter and root colonization) under different experimental conditions, the highest direct effect on oil and protein yield was obtained from oil percentage and protein percentage, respectively. Based on cluster analysis results, the "Darab 2" and "Darab 14" cultivars are suitable for cultivation in different conditions. Also, it sems that seed yield and oil percentage traits to achieve high oil yield and seed yield and protein percentage traits as selective indices to achieve high protein yield suitable.

Environmental factors make changes in the amount and type of secondary metabolites. To study the effects of temperature regimes on secondary metabolites and the expression of genes involved in biosynthesis pathway of thymol and carvacrol in thyme, an experiment was conducted in a growth chamber for one month with three thermal treatments including heat, cold and normal temperatures. Essential oil compounds were measured by Gc / MS and Gc and the expression of TvTps1, CYP178 and CYP180 genes assayed by qRT-PCR. Both heat and cold temperatures increased the phenolic monoterpen compounds (thymol and carvacrol) compared to normal condition. High temperature led to significant increases in carvacrol while low temperature resulted in a great increase in the amount of thymol. Gamaterpenin level was declined due to thermal treatments. Gene expression analysis revealed that the cold condition increased the expression of TvTps1 and CYP178 genes, while heat decreased the expressions. CYP180 and CYP181 were highly expressed under both cold and heat conditions, although the amount of expression was much higher under high temperature. Generally, the results indicated that the environment temperature played a key role in thyme metabolites type and content. It could be concluded that the regions with high and low temperatures were suitable for carvacrol and thymol production, respectively.