Impact of drought stress on lentil genotypes through investigation of morpho-physiological traits

To evaluate the drought tolerance of lentil by morpho-physiological traits, 10 lentil lines were planted in randomized complete design with 3 replications under non-stress and drought stress conditions in agricultural station of Islamic Azad University, Ardabil, Iran in 2016. Grain yield, plant height, number of pods and 1000 kernels weight, leaf relative water content, activity of superoxide dismutase and catalase enzymes and cell membrane stability were measured. Results showed that differences among genotypes were significant in all of traits except for relative water content and CAT activity (under non-stress). Under drought, ILL-10088, ILL-10053 and Bilesavar, with 1244, 1153 and 1107 kg/ha and under non stress condition, ILL-10088, with 1905 kg/ha had the highest yield. Considering the yield of cultivars in two environments, ILL-10088, BileSavar, ILL-10017 and ILL-468 were the most tolerant cultivars. Results showed that under drought, grain yield had significant correlations with catalase activity, relative water content and cell membrane stability. Under non-stress condition, yield had significant correlations with relative water content, cell membrane stability, 1000 kernels weight and number of fertile pods. In regression analysis, using stepwise method, under stress, relative content remained in model. However, under non-stress condition, relative water content and cell membrane stability remained in model. Principle component analysis could separate susceptible cultivars from tolerant cultivars better than cluster analysis. Regarding to the presence of genetic diversity, ease of use and strong relations with yield, relative water content and cell membrane stability were proposed as indirect criteria for selection of drought tolerance in lentil.