Study in Effects of drought stress on yield, yield components and some important physiological traits in soybean genotypes

To assess the effects of drought stress on yield and some traits related to growth in soybean, two experiments were conducted as normal and 50% decreas in soil water to FC as stress condition in a randomized compelet block design with three replications and 10 genoytpes in Karaj in 1394. Results showed, that drought stress had different effects on traits. So that, the greatest increase was in %empty pod and the most decrease was in yield per plant and seed number. Some of traits such as the first pod, seed number, nod number had sever damage from drought,too. Seed filling period and yield decreased in susceptible genotypes,significantly but in tolerant genotypes had no significant decrease. Whiles, %empty pod and RSD% had significant increase in sensitive genotypes. Obtained results revealed that, genotypes had different reactions to drought in pigments of their leaves. Although, drought had increased pigments as average; leaf pigments in tolerant genotypes decreased whiles increased in susceptible genotypes.