The role of physiological and biochemical traits in improving the performance of soybean genotypes under water deficit tension

In order to evaluate the effect of physiological and biochemical traits on tolerant water deficit of 15 imported genotypes soybean, a pot experiment with 15 imported genotypes was carried out in a factorial arrangement based on randomized complete blocks design with three replications in Damavand city in 2017.The first factor contained 15 soybean genotypes and second factor included two levels of normal irrigation and irrigation disruption at 50 percent podding time to seed filling stage. The results of analysis variance showed that that there was a variety of genotypes under abnormal conditions and normal irrigation. The results of the mean comparison showed that in non-tension conditions, genotypes 3, 5 and 13 had the highest chlorophyll a, genotype 15 the highest total chlorophyll, genotype 5 most carotenoid genotypes, 13 and 14 genotypes the highest protein content, genotypes 7 and 13 the highest number of leaves, genotypes 2 and 10 the highest dry weight of plant and genotype 13 had the highest harvest index and grain yield. Low irrigation tension reduced yield and some physiological and morphological traits. Under the present conditions, some traits also increased. Genotype 3 had the highest chlorophyll b and chlorophyll b to a ratio, genotype 5 and 8 had the highest flavonoid, genotype 5 had the highest proline content and genotype 14 had the highest yield. The main components analysis showed that under normal irrigation conditions, the first four components explained 67.85 percent of the total variance, so that the contribution of the first to fourth components were 38.81, 20.65, 15.62 and 10.57 percent. Under tension application conditions, the first four components explained 82.26 percent of the total variance, so that the share of the first to fourth components was 35.58, 25.20, 13.66, and 7.80 percent, respectively.