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In order to study the effects of different amounts of irrigation on grain yield and chlorophyl amount of leaves in growth stages of 4 rapeseed cultivares, an experiment was performed in the agriculture research station of Khorramabad in 2009-2010.The design was a split-plot with irrigation treatments as main plot in a randomized complete block design and cultivares as sub plots.4 irrigation periods included normal irrigation (as control) , cuting of irrigation from stem stage, irrigation cut from flowering stage and irrigation cut from poding stage. 4 cultivars included R.G.S003, sarigol, Option 500 and Hyola 401.The results showed that water deficiency stress had significant decrease on pod number in plant,weight of 1000 grain and decreased grain yield,grain oil yield,biological yield and harvest index of treatments to control consequently. Since limited irrigation water treatments to cause control increased water use efficiency, therefore these treatments can be used to economize water use. The comparison of 4 cultivares showed that in regard to pod number in m2 , pod number in plant, grain yield, biological yield, grain oil percent, and grain oil yield. Hyola 401 had relative superior to option 500,R.G.S003 and sarigol. In total , if water was limited, cutting of irrigation from poding stage in comparison to control and use of Hyola401 cultivar was favoured because grain yield and oil yield increased.

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Drought is one of the most important factors limiting plant growth around the world and it is the most common environmental stress. The lack of water in the pastures causes growth reduction and the establishment of varieties in this areas. Due attention to ecological importance of pastures and effects of three level of drought stress FC, FC50% on ، for conserve the soil , in present research, the growth of varieties:Secale montanum, Bromus tomentellus,Agropyron desertorom from grasses and Onobrychis sativa , Medicago sativa from legoms was considered..From each species two genotypes were selected. Factorial experiment based on completely randomized design in 4 replications was conducted in greenhouse conditions. Root length, shoot length, seedling length, root to shoot ratio, root, shoot and seedling dry weight as well as dry weight to fresh ratio , the amount of chlorophyll a,b,and total were assessed. Under drought stress increased root length and the amount of chlorophyll increased and the most other traits, especially at FC 50% reduction was significant. Secale cermond ecotype seedlings had the most growth and Agropyron cristatum ecotype seedlings had the lowest growth rate and chlorophyll. In examining the interaction of drought and species the highest total chlorophyll and b chlorophyll were observed in Medicago 44 that were treated with FC 50%.From ten under studied ecotypes under drought stress,Secale cermond had the better growth.

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In order to investigate the effect of soil cobalt concentrations on chlorophyll a,b and total chlorophill density in pinto bean,a pot experiment was conducted in Shahrekord University's greenhouse,separatly for two pinta beans cultivars Khomein and Talash in cropping year 2010-2011. The experiment included five treatments (0,20,70,150,and 220 mg of cobalt chloride per kg of dry soil) and four replicates arranged in a completely randomized design. After physiological maturity of plants,chlorophylls a and b were measured and total chlorophyll in middle leaves of each pod was calculated as sum of chlorophylls a and b. Results showed a tendency to increase (up to soil CoCl2 concentrations of 20 mg/kg) and then a decrease in both chlorophylla.b and totall densities (at soil CoCl2 concentrations more than 70 mg/kg). Totally,Soil CoCl2 concentrations of 150 and 220 mg/kg significantly decreased the chlorophyll densities compared to control (P<0.05). Despite the negative and significant effect of high soil cobalt,more than 100mg/kg CoCl2, it seems that low soil cobalt(lower than 20mg) for Khomein cultivar and lower than 70mg Co for Talash,may have positive effect on chlorophyll densities in pinto bean leaves. The tolerance threshold for chlorophylls a,b and total chlorophyll were estimated to be approximately 60,30 and 40 mg of CoCl2 per kg of dry soil,respectively,for Khomein pinto bean.For Talash cultivar,the tolerance threshold for chlorophylls b and total was obtained 90 and 55 mgCoCl2 on kg soil. The synthesis of chlorophyll b in pinto beans leaf,in Khomein and Talash cultivars, is more sensitive to high soil cobalt conditions than chlorophylla.

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This experiment was carried out in cropping years 2010-2011 in Agricultural Research Center of Dezful as split plot in a randomized complete block design with three replications. Treatments consisted of three cultivars of mung bean seeds (Parto, Indian lot and promising line of mung VC61) in subplots And three irrigation levels (no stress, mild stress and severe stress with 120 , 180 and 240 mm from evaporation pan, respectively) were in the main plots. In this investigation, physiological traits including chlorophyll content, stomatal conductance, biological yield and leaf area index were measured. Drought stress had a significant effect in one percent level on chlorophyll content and stomatal conductance, decreasing in chlorophyll content and stomatal conductance in leaves was observed. Also, there was significant difference in cultivars and stomatal conductance was the highest in VC61 cultivar. VC61 cultivar with the 71/71 had the highest SPAD value and the amount of chlorophyll a + b VC61 cultivar, Indian and Parto cultivar was 1/364, 1/148 and 1/213, respectively. Drought stress had a significant effect on biological yield and the leaf area index at 5% level. Such as this traits decrease with severity of drought stress.

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In Khouzestan, reduce temperature in January and Februaryis a dominant climate phenomenon that causes damage to the plant and thus the yield. In this research the effect of cold tension in tillering stage on yield, yield components and some phonological and physiological traits was investigated in a factorial experiment under controlled greenhouse conditions with five wheat genotypes (cultivars Chamran, Virinak, Star, Karkheh and line M-83-17) and at four ambient temperatures (no cold, +3, 0, -3 C°) in a completely randomized design with three replications. The results showed there was a significant difference among genotypes in terms of cold tolerance and the genotypes difference and the effect of cold and their interactions on yield and yield components and some physiological traits was significant. At no tension conditions and 0 C° temperature the highest grain yield was belonged to line M-83-17 at rates 0.8 and 0.3 gram in main stem, respectively and Star cultivar at +3 and -3 C° temperatures with 0.4 and 0.45 gram in main stem, respectively. The lowest fluorescence reduction was observed at least, at Chamran cultivar at 0 C° tension and the lowest fluorescence increase, maximum in Chamran cultivar at -3 C° tension. The maximum photochemical photosystem II efficiency was observed in Star cultivar. According to SSI and STI indices, Star and Chamran cultivars had more sustainability yield in cold tensions. The changes of investigated traits in the studied genotypes shows different reaction of genotypes which itself is due to genetic diversity of these genotypes.

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This experiment was conducted in order to investigate the effect of post anthesis drought tension on agronomical traits, biochemical characteristics and some physiological characteristics. The experiment was carried out in pot culture experiment as factorial experiment based on complete randomized blocks design in three replications in Campus of Agriculture and Natural Resources of Razi University, Kermanshah in 2011-12 cropping year. In this experiment, drought tension was considered at generative growth stage (from the anthesis stage until end of soil moisture growth stage, around 30 percent of field moisture) and different wheat genotypes consisted of Pishtaz, DN-11, Sivand and Marvdasht were investigated as the second factor. The results showed that drought tension after anthesis decreased grain yield by decreasing of 1000- grain weight. Under drought tension after anthesis, Marvdast and DN-11 genotypes had the lowest grain yield. The occurrence of drought tension significantly decreased soluble protein content. The activity of superoxide dismutase enzyme increased after anthesis in drought tension conditions. Catalase and peroxidase activity in the sensitive genotypes (Marvdast and DN-11) was less than the tolerant genotypes (Pishtaz and Sivand). It can be concluded that activating the enzymes defense system of catalase, peroxidase and superoxide dismutase antioxidants in wheat genotypes has had a major role in increasing tolerance to drought tension.

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In order to investigate the effect of levels of drought tension and nitrogen on yield and qualitative  and physiological traits of potato, this experiment as split plots was carried out  based on randomized complete blocks design, with three levels of drought tension S₁ (control, providing 100 percentage water requirement), S₂ (providing 75 percentage) and S₃ (providing 50 percentage of water requirement of potato after emergence to the end of the growing period) as the main factors and four nitrogen fertilizer treatments  N₁ (providing 100 percentage fertilizer requirement), N₂ (66 percentage), N₃ (33 percentage) and N₄ (without applying nitrogen fertilizer) as the sub factors in Agriculture and Natural Resources Research Center of Chahar Mahal va Bakhtiari province. In this experiment maximum tuber yield gained from without tension treatment (S₁) by the amount of 55/9 tons per hectare that had no significant difference at five percent level with S₂ treatment but S₃ with significant difference than two mentioned treatments, produced the average yield 31/7 ton per hectare. N₁ and N₂ treatments produced the highest tuber yield without statistically difference at five percentage level, but lack of nitrogen consumption (N₄) led to the lowest tuber yield (38/7 ton per hectare). Generally, in S₂ and S₃ tension levels, N₂ treatment caused access to the maximum tuber yield. Due to the reduction of tuber yield in S₂ and S₃ treatments within the highest nitrogen consumption level (N₁), the interaction between drought tension and nitrogen on tuber yield was significant at one percentage level.

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In order to investigate the effect of organic nitrogen on fluorescence changes of photosynthetic pigments of Hamedani alfalfa under drought conditions, this experiment as factorial was conducted in a completely randomized design with three replications. The treatments of experiment consisted of drought tension in three levels of 35, 60 and 85 percentage of field capacity and nitrogen fertilizer at four levels of without fertilizer, 30, 60 and 90 kilogram nitrogen per hectare. The results showed, the interaction of nitrogen at drought at one percent level on chlorophyll a concentration, total chlorophyll and at the level of 5 percent on chlorophyll b concentration, the ratio of chlorophyll a to b and carotenoids was significant. With increasing levels of dryness the amount of chlorophyll a concentration, b, total and carotenoids was reduced but ratio chlorophyll a to b was increased. Nitrogen consumption improved photosynthetic pigments so that chlorophyll a concentration, chlorophyll b, total chlorophyll increased with nitrogen consumption and the ratio of chlorophylls and the amount of carotenoids were reduced. Nitrogen fertilizer on the maximum fluorescence (Fm), quantum yield (Fv / Fm) in pre-tension and on the minimum fluorescence (Fo) and (Fv / Fm) in after three days tension and on (Fv / Fm) in a week after tension had a significant effect. Drought tension had a significant effect only on (Fo) and (Fm) in three days after tension and on (Fo) and (Fv / Fm) in a week after tension. The minimum and maximum amount of protein was obtained in the conditions of without using nitrogen (4.79 milligram on gram wet weight) and consumption of 90 kilogram nitrogen per hectare (10/06 milligram on gram wet weight) was obtained. Nitrogen interaction in dryness, on stem height and plant dry weight was also significant. In tension conditions, stem height and plant dry weight reduced.

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According to limited availability of water for crops production, fining genotypes with optimal efficiency of water use is among the research priorities. For this purpose this research was conducted in order to investigate the effect of water deficiency tension on photosynthesis indices and finally production and forage yield of three sorghum genotypes as factorial in a completely randomized design in University of Mohaghegh Ardabili research greenhouse in 2013. The experiment treatments consisted of water deficiency tension at four levels (80, 65, 45 and 25% of field capacity) and three genotypes of sorghum (KFS17, KFS6 and KFS2). The results showed that the main effect of water deficit tension and genotype had significant difference in most measured traits at one percentage probability level. Interaction between water deficit tension and sorghum genotype was significant only on the amount of chlorophyll a, carotenoids, chlorophyll stability and forage yield. So that the deficit water tension caused decreasing of chlorophyll a, b, total chlorophyll, maximal fluorescence (Fm), quantum yield of photo system II (Fv/Fm) and forage yield and caused increasing in chlorophyll a to b ratio, carotenoids, chlorophyll stability, Fo (minimal fluorescence in dark adapted conditions), Ft (fluorescence intensity or instantaneous). Although KFS6 genotype had the highest value in many of the measured traits, however, the highest yield was belonged to KFS2 genotype and then KFS17. Also based on regression analysis the KFS17 genotype showed the highest correlation between chlorophyll a, total chlorophyll and carotenoid amounts with the yield. Generally, yield reduction in KFS2 genotype can be related to consume more plant photosynthesis materials in order to withstand against the tension.

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Much of the lands under wheat in the world is in arid and semiarid regions. In these regions the water requirement of wheat in all development stages can not be fully met. This research was conducted in this regard and in order to investigate the effect of post anthesis water deficiency tension on quantity and quality of grain yield and some physiological characteristics of wheat different cultivars. This experiment was conducted in the potted form as three-factors factorial for physiological traits and two-factors for yield quantity and quality and based on randomized complete blocks design with three replications at Campus of Agriculture and Natural Resource of Kermanshah Razi University during 2011-12 cropping year. Three investigated factors included: 1) humidity treatment in two levels of non-tension (field capacity) and water deficiency tension from pollination stage till the end of growing season (30 percentage field capacity), 2) different wheat genotypes (Pishtaz, DN-11, Sivand and Marvdasht) and 3) sampling date in two levels including: 11 and 17 days after anthesis. The results showed that in tension and non-tension water deficit conditions Marvdasht cultivar had the lowest grain yield. Among the other investigated genotypes (in two humidity conditions), Pishtaz had the highest grain yield. The lowest grain yield drop in water deficit conditions compared to non-tension was relared to Pishtaz cultivar, as well. Applying water deficit tension caused significant reduction of chlorophyll a and b concentration, total chlorophyll and carotenoids, maximum quantum yield of photo system II, viability index and relative water content. Also, water deficit tension caused decreasing in starch content and total dry mater and increasing in fiber content and   grain protein of investigated genotypes.

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In order to investigate the effect of partial root zone drying on yield and some physiological characteristics of two potato cultivars, this experiment was performed as split- split plots based on randomized complete blocks design with three replications in Chahar Mahal va Bakhtiari farm Research Center of Agriculture and Natural Resources in 2013-14. The tested treatments in this research included two irrigation methods furrow and tape drip irrigation at the main plots, two potato cultivars included Almera and Burren in  sub plots and four deficit irrigation treatments at four levels of irrigation at the amount of 100, 80 and 65 percent  of soil allowed moisture depletion and incomplete root irrigation (PRD) as the sub-sub plots. The results showed that Burren cultivar in comparison with Almera cultivar in all the deficit irrigation treatments had superiority regarding to  tuber yield, water productivity and drought tolerance as Buren cultivar compared with Almera cultivar caused increasing in total tuber yield and water productivity by 19 percent. Effect of deficit irrigation on tuber yield, water efficiency, starch percentage, soluble sugar content, amount of proline and plant chlorophyll was significant at one percent probability. The highest amount of tuber yield equals to 59/02 tons per hectare due to to the Bourne cultivar and full irrigation was obtained. Most water efficiency equals to 13/20 kilograms per cubic meter was obtained related to Bourne cultivar and PRD treatment. Therefore, due to resource constraints for efficient use of water, Bourne cultivar as a cultivar with high quality and quantity yield, and deficit irrigation PRD was recommended as a way to conserve water.

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In order to evaluate the effect of mycorrhiza fungi on ecophysiological characteristics of barley cultivars in response to inoculation with different strains of Pseudomonas fluorescence under rain fed conditions, this factorial experiment in randomized complete blocks design was conducted at Ardebil Islamic Azad University research farm. Experimental factors consisted of mycorrhiza fungi Glomus mosseae species (non-inoculated and inoculated), Pseudomonas fluorescence bacteria srains (four stains of Pseudomonas fluorescence bacteria S153, S169, S4, S8, and non-inoculated) and barley cultivars (Dasht and Sahra cultivars). In both cultivars the highest seed yield was obtained from application of mycorrhiza and strain S169 treatment (in Dasht cultivar with an average 1293 and in Sahra cultivar with an average 1752 kilogram per hectare). Also, in physiological traits, the highest amount of chlorophyll a was obtained from application of mycorrhiza fungi treatment and non-inoculated with bacteria in Sahra cultivar and chlorophyll b, total chlorophyll and soluble sugar was obtained from application of mycorrhiza fungi treatment and inoculation with Pseudomonas bacteria strain S153, in Sahra cultivar. The greatest amount of phosphorous grain was observed in mycorrhiza application treatment and inoculation with strain S153 in Dasht cultivar, while the most amount of grain nitrogen was obtained from treatment application of mycorrhiza fungi and inoculation with bacteria S4 strain in Sahra cultivar. Although, the strains used in this study had a different reaction to cultivar and application of mycorrhiza, but most of the measured traits were superior, compared to non-inoculated treatment with bacteria.

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In order to investigate the effect of nip and drought tension on chlorophyll index, relative water content, electrolyte leakage and grain yield of maize single cross 400 under different levels of salicylic acid, a field experiment carried out in split split plots in randomized complete block design with three replications in the greenhouse and Agricultural Research Station of Ferdowsi University of Mashhad during the cropping year of 2014. In the present experiment the main factor, cold tension at two levels (non- nip tension and nip tension), sub-factor included three levels of drought tension (irrigation equivalent to 100 percent plant water requirement (non-tension, control)), irrigation equivalent to 75 percent of plant water requirement and irrigation equivalent to 50 percent plant water requirement) and sub sub factor foliar application salicylic acid (non-foliar application (control), foliar application 200 micro molar and 400 micro molar foliar application) was considered. The obtained results indicate chlorophyll meter index, relative water content and electrolyte leakage are influenced under drought tension conditions; as water deficiency tension, chlorophyll index decreased relative water content and electrolyte leakage, increased grain yield. Also, salicylic acid foliar application improved the chlorophyll index, leaf relative water content, increasing electrolyte leakage and grain yield. Nip treatment interaction on drought tension using 200 micro molar foliar application of salicylic acid improved the chlorophyll index. According to the results, using the appropriate concentration of salicylic acid are recommended for improving environmental tensions such as drought and nip to achieve the optimal performance.

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This research was carried out in order to biomolecular investigate drought tension tolerance in two wheat cultivars inoculated with plant growth promoting rhizobacteria (PGPR) in the research greenhouse of Islamic Azad University, Karaj Branch in  2013-14 cropping year. The experiment design was in the split factorial arrangement based on a randomized complete blocks design with three replications. The main plot included two levels of desirable irrigation and drought tension (deficit irrigation in the pollination stage until the end of full maturity) and sub plots consisted the PGPR bacteria at four levels: 1) inoculation seed with Azotobacter chroococcum 2) inoculation seed with Azospirillum lipoferum 3) simultaneous use of both bacteria Azotobacter + Azospirillum 4) non-application of bacteria (control) and two bread wheat cultivars consisted of Sirvan and Marvdasht. Experiment traits included the activity of superoxide dismutase antioxidant enzyme (SOD), the activity of biochemical biomarker Malondialdehyde (MDA) amount of chlorophyll a, b and a + b. Results of the experiment showed that simple effect of irrigation, cultivar and bacteria treatments was significant on all the studied  traits (01 / 0≥P). The activity of superoxide dismutase enzyme (SOD) in drought tension treatment was higher than full irrigation (normal). Sirwan and Marvdasht cultivars with 3.6 and 2.7 units per gram of protein, showed the higher and lower SOD enzyme activity, respectively. Sirvan cultivar compared to Marvdasht cultivar had less amount of biomarker MDA activity (27.424 milligram on gram fresh weight of tissue) and the higher content of chlorophyll a, b and a+b with 3.255, 1.578 and 4.811 (milligram on gram fresh weight of tissue), respectively.

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In order to investigate the effect of superabsorbent polymer on yield and some physiological characteristics of spring maize under water deficit tension, this experiment was conducted as split plots  in a randomized complete blocks design with three replications in a field located in Hamidieh. Experiment treatments included irrigation intervals (60, 90 and 120 millimeter evaporation from evaporation pan class A) in the main plots and different amounts of superabsorbent (zero, 75 and 150 kilogram per hectare) in subplots. The results showed that the effect of irrigation intervals and superabsorbent was significant on grain yield, yield components, chlorophyll index and relative content of leaf moisture. The highest grain yield and yield components and chlorophyll index was obtained from treatment of 60 millimeter evaporation and 150 kilogram per hectare of superabsorbent. The highest grain yield by an average of 606 gram per square meter was obtained from treatment of 60 millimeter evaporation. Drought tension caused a significant decrease in chlorophyll index and leaf relative water content. In general, the consumption of 75 kilogram per hectare superabsorbent under mild tension conditions resulted in compensation for damage caused by tension.

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Drought tension is one of the most important tensions in reducing germination of plants. In order to evaluate the effect of drought tension on seed germination characteristics and photosynthetic pigments maternal genotypes of safflower, a factorial experiment based on completely randomized design with four replications was conducted at seed technology laboratory of Shahed University in 2015. The examined factors included seeds produced in two levels of optimal irrigation and application of drought tension after flowering stage on mother plant and four genotypes of Safflower including Soffeh Isfahan, Goldasht, Mexico12 and Line 411. The results showed that genotype and drought tension had significant effect on under investigation traits. In addition, the results showed that drought tension increased the traits average length of germination time, seedling length, chlorophyll b content and carotenoid content and reduced other assessed traits. The seeds produced in conditions of drought tension on rootstock genotype Mexico 12 had the highest percentage of germination (94.59 percent), length of seedling vigor index (202.44), seedling vigor weighted index (8.51) and the amount of chlorophyll b (0.42 milligram per gram wet weight). In general, application the terminal drought tension on the mother plant of the investigated genotypes reduced seed germination characteristics and seedling growth of safflower genotypes. Totally, seed of those cultivars that their mother plant encountered with drought tension is not suitable for planting in areas with irrigation constraints or drought probability in these areas. 

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In order to investigate the yield, yield components, growth and physiological indices of maize hybrids in response to Nitroxin bio fertilizer application containing inoculant Azotobacter choorcoccum and Azospirillum brasilenese bacteria, in addition to the amounts of nitrogen fertilizer, this experiment was performed as split plots based on randomized complete blocks design with four replications. Main plots consisted of combining four levels of fertilizers treatment (100 percentage chemical fertilizer, 75 percentage chemical fertilizer + 100 percentage bio fertilizer, 50 percentage chemical fertilizer + 100 percentage bio fertilizer and  25 percentage chemical fertilizer + 100 percentage bio fertilizer) and sub plots included maize hybrids (Single Cross 704 hybrid, Mobin hybrid and Karoun hybrid). Results showed that maximum biological yield, grain yield, one thousand grain weight and ear length were belonged to combined use of 50 percent nitrogen fertilizer plus 100 percent Nitroxin bio fertilizer in Karoun hybrid. Single Cross 704 hybrid in the amounts of 100 percent chemical fertilizer application, had the highest number of grain per ear, number of grain per row, inoculation percentage and lowest length of ear without grain and percentage of ear without grain. The maximum length of ear without grain and percentage of ear without grain was obtained from treatment 75 percent nitrogen chemical fertilizer application plus to 100 percent bio fertilizer and Mobin hybrid. The investigation of results showed no significant difference among fertilizer treatments, as well as hybrids in terms of chlorophyll index. However, Karun hybrid had a higher chlorophyll index than two other hybrids.

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