grain yield, leaf chlorophyll, proline and soluble carbohydrates content of linseed under different irrigation regimes

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.