The relationship between accumulation of compatible osmolytes and superoxide dismutase (SOD) activity with grain yield of chickpea genotypes in responses to drought stress was studied in two separate experiments; afield and a pot experiments at the Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran, in 2010-11 cropping season. Field experiment was carried out as split plot arrangement in randomized complete blocks design (RCBD) with three replications. Irrigation and rainfed conditions were assigned to main plots and chickpea genotypes were randomized in subplots. Pot experiment was conducted as factorial arrangement using RCBD with two factors including irrigation treatments (irrigation at -3 (control) and -12 bar (stress) of soil water potential) and 19 chickpea genotypes as second factor with three replications. Results showed that the effects of drought stress and genotype on grain yield was significant in the field experiment. Genotypes showed different responses to drought stress. In pot experiment some physiological traits showed specific relationship with genotype performance under field condition. In the reproductive stage, drought stress decreased leaf soluble protein from 17.5 to 5 mg.g-1. However, there was no relationship between concentration of total soluble leaf protein and drought tolerance, but increasing of proline and soluble carbohydrates concentration, improved stress tolerance index especially in the vegetative stage. Results showed positive relationship between accumulation of proline and soluble carbohydrates concentration (r = 0.59**), that revealed a common role of these osmolytes in improvement of drought stress tolerance in chickpea genotypes. In the vegetative stage, drought stress increased proline concentration from 0.27 to 2.4 mg.g-1 and soluble carbohydrates from 14 to 16. mg.g-1. These results indicated that soluble carbohydrates accumulation had stronger relationship with drought tolerance rather than proline concentration, and soluble carbohydrates had two fold higher osmotic adjustment than proline. It can be concluded that accumulation of soluble carbohydrates is a better index in selection for drought tolerance in chickpea. However, results showed no relationship between SOD activity and stress tolerance in chickpea genotypes.

In order to compare yield and forage quality, six local genotypes of common vetch (Vicia sativa) were sown in two separate experiments under irrigated and dry land farming system using randomize complete block design with three replications in khorramabad agricultural research station during 2005 and 2006. Data were collected for Forage fresh and dry matter (DM) yield, plant height and quality traits as: dry matter digestibility, (DMD), crude protein (CP), water soluble carbohydrates (WSC), crude fiber (CF), acid detergent fiber (ADF), neutral detergent fiber (NDF) and total ash. Results of combined analysis showed significant differences between two conditions for all of traits except DMD. The average values of DM (2.76 and 2.35 ton/ha), CP (24.8 and 21.6%), and WSC (10.9 and 12.9%) were obtained for Irrigated and drought condition respectively, indicated higher values of both DM yield and CP and lower values of WSC in Irrigated conditions. Genotype effect was significant for forage yield, plant height, WSC and NDF. Results of correlation coefficients showed that forage yield had positively correlated with plant height, WSC and CF and negatively correlated with CP. Whereas, WSC had positively correlated with DM yield, plant height and DMD and negatively correlated with CP, ADF, NDF and total ash. Using cluster analysis, 6 genotypes were classified into two groups. Using biplot diagram based on 5 drought resistance indices, six genotypes were scattered. Talarizan (Azna) with average values of 3.1 and 2.7 ton/ha DM yield for optimum and dry condition, respectively had higher values in both conditions and recommended for cultivation in more rainy regions of Lorestan province. Genotypes of Torshabad (Doruod) and Fahre (Aligudarz) with average values 2.55 and 2.72 ton/ha DM yield, respectively for drought condition, were identified as tolerant to dryness and identified for cultivation in dry land farming system. Genotypes of Doruod and Bawki (Azna) with average values of 2.39 and 3.01 ton/ha forage production in irrigated condition recognized as sensitive to dryness and recommended for cultivation in irrigated conditions. Among the productive genotypes, Fahre with average values of 12.74% WSC had good forage quality.

Studying the physiological responses of linseed genotypes to water deficit stress may be helpful in recognizing the linseed resistance mechanisms to the latter stress factors. Therefore, a split plot RCBD field experiment was conducted with three replications to explain interrelations of leaf chlorophyll, proline and soluble carbohydrates content and grain yield of six linseed genotypes under three irrigation regimes. Three levels of irrigation: 70 (no stress), 115 (moderate stress) and 145 mm (severe stress) evaporation from a Class-A Pan served as the main plots and six linseed genotypes consisting of C1, C2, C3, B, Khorasan and 33 were considered as sub plots. Water deficit led to significant decreases in grain yield and chlorophyll content, but it led to increases in proline and soluble carbohydrates content of linseed leaves. Genotype B produced the highest grain yield (2193 kg ha), genotype C1 the greatest decrease (34%) in chlorophyll content and genotype B the highest increase (93%) in soluble carbohydrate content under severe stress. C1, C2, C3 and Khorasan indicated the greatest and B and 33 genotypes the smallest increases in proline content under sever water deficit stress. At least with present set of conditions, increasing soluble carbohydrates played a more significant role, compared to proline and chlorophyll content, in tolerance to moisture deficit stress.

To study the variation in some agronomic characteristics and soluble stem carbohydrates at anthesis in spring wheat, 196 wheat genotypes received from the International Maize and Wheat Improvement Center (CIMMYT) were evaluated in a field experiment at Hasan Abad Field Research Station, Darab, Iran, in 2008-2009 growing season. Analysis of variance of data revealed that spring wheat genotypes were significantly different (P <0.01) for days to heading, plant height, days to physiological maturity, 1000 grain weight and grain yield. The genotypes were also significantly different (P<0.05) for grain growth duration. Range of variation for some characteristics as days to heading was narrow (106-119 days). However, the range of variation for soluble stem carbohydrates at anthesis was very wide (8.5-95.5 mg.g-1 dry matter). Variation in the grain growth rate was 0.52-1.18 mg.day-1 and grain yield varied from 987–6095 kg.ha-1. Genetic correlation between soluble stem carbohydrates at anthesis and grain yield was negative but significant (-0.394**). It was indicated that the accumulation of high amount of stem soluble carbohydrates at anthesis without remobilization process can not effectively increase grain yield under terminal drought conditions. Path analysis revealed that the direct effects of four characteristics: days to heading, plant height, grain growth rate and soluble stem carbohydrates at anthesis on grain yield were significant. Early maturity and grain growth rate were under genetic control and correlated with grain yield under terminal conditions of this study that can be used in wheat breeding programs for improvement of grain yield under terminal drought conditions.

In order to investigate the effect of drought tension during the flowering stage on proline content, total soluble carbohydrate, fructose, glucose and sucrose in bean leaves, an experiment was conducted as split plots based on randomized complete blocks design with three replications. Main factor included four cultivars of bean (Taylor, COS16, Khomein and Akhtar), sub factor consisted of drought tension in three levels (30, 60 and 100 percent field capacity) and sub-sub factors was tension duration in two levels (three and nine days). The results showed drought tension decreased the relative water content and sucrose significantly and increased the amount of and electrolyte leakage, total soluble carbohydrates, fructose, glucose and proline. There was a significant negative correlation between relative water content and electrolyte leakage, soluble carbohydrates in water, fructose and glucose content. In conditions of water tension, accumulation of soluble carbohydrates and proline in Taylor and COS16 tolerant cultivars was more than sensitive Akhtar was Khomeini. Increasing time duration of tension from three and nine days caused a significant increase in proline, glucose, fructose and total soluble sugars amounts. The interaction effect of tension × cultivar and tension × time on all evaluated traits was significant, while the cultivar × time duration interaction had a significant effect on electrolyte leakage, proline and total soluble carbohydrates. The results of this investigation showed that proline and carbohydrates are involved in tension tolerance mechanisms and their metabolism is influenced by soil water tension.

Mutant genetic materials are valuable tools for understanding the physiology of remobilization and could be useful in the breeding of drought tolerant varieties. Two advanced mutant lines of bread wheat (T-67-60 and T-65-7-1) along with their wild type (Tabasi Cv.) were planted at two moisture conditions (normal and 30-40% of field capacity) as a factorial experiment in format of completely randomized design with three replications. Drought treatment initiated at full heading stage (Zadoks 60) and soluble carbohydrates were measured 5 times (0, 7, 14, 21 and 28 days after anthesis) in the stem internodes, separately. Based on the results it could be said that changes in the receiving signals for senescence phenomena under drought stress, capability of the sink, the rate of the reserves assimilated before anthesis and the use of reserves capacity over stem are the factors affecting the differences of genotypes in remobilization of stem soluble carbohydrates under drought stress. It seems that under drought stress mutant line T-65-7-1 was significantly better than wild type cultivar in terms of remobilization and its efficiency and also for faster receiving signals of senescence (as a stimulating factor of remobilization), higher capability of the sink (more grain yield) and higher reserve capacity (higher maximum soluble carbohydrate concentration and specific content). Also, mutant line T-65-7-1 has utilized full ability of all parts of the stem for remobilizing soluble carbohydrates during grain filling.

The aim of the present study was to determine the effects of different months and pests on proline and sugar contents of leaves of Robinia pseudoacacia L and Ailanthus altissima Mill. Swingle. The study was carried out at research station of Moghan College of Agriculture. Four samples were selected randomly from each of three hectare sites. Each sample was collected in five replications in different months from healthy trees and pest affected trees. Fresh and dry weight, the level of proline and soluble carbohydrates were determined using spectrophotometric methods. For comparison of data means between healthy and pest trees independent sample t-test and for comparison of means between data in different months Duncan method was used. The results showed that in dry month, (July-Sep) proline and soluble carbohydrates increased. Fresh and dry weight of leaves increased in healthy trees but proline and soluble carbohydrates increased in pest trees. Proline and soluble carbohydrate are involved in tolerance mechanisms against stress and this was the main strategy of plants to avoid detrimental effects of stress.

Water Water deficit especially after heading is one of the most effective factors of wheat yield loss in Iran and across the world and identifying the physiological traits related to plant resilience is of great importance in screening for tolerant varieties. The objective of this study was to evaluate the variation in stem reserves accumulation capacity and its relationship with remobilization in some wheat cultivars. 22 wheat cultivars were cultivated in a split plot design with three replications, full irrigation and 40% of field capacity being main plots. The amount of accumulation and remobilization was estimated by measuring internodes weight and stem soluble carbohydrates content (WSC). Significant genotypic variation among cultivars was observed under both normal and drought conditions. Maximum accumulation was found in lower internodes followed by peduncle and penultimate using dry weight measurement method. In WSC measurement method, however, maximum accumulation was observed in penultimate followed by lower internodes and peduncle. Cultivars ranking based on accumulation was also different in two methods. Drought stress caused decline in internodes weight, WSC and yield and remobilization efficiency. The specific stem weight had the highest correlation with remobilization. Significant correlation was found between grain yield and remobilization, specific stem weight and WSC.