Study of quantitative and qualitative traits and their relationships with grain yield in white bean (Phaseolus vulgaris L.) under optimum and limited irrigation conditions

Drought stress often is a limited factor in world that threatns crop yield. Application of breeding and selection of tolerant genotypes to abiotic stresses are logical approach for determination of tolerant genotypes that have a high performance under drought. In order to study quantitative and qualitative traits and their relationships with grain yield in white bean genotypes under optimum and limited irrigation conditions, 15 white bean genotypes were studied in two experiments using randomized complete block design with three replications in experimental field, Faculty of Agricultural, The University of Tehran in 2004 cropping season. Combined analysis of variance showed high genetic variation for most of the traits. Some traits had high genetic variation under both conditions. Stress Susceptibility Index (SSI), Geometric Mean Productivity (GMP) and Stress Tolerance Index (STI) had positive correlation with yield under optimum and limited irrigated conditions. Thus genotypes with greater GMP, STI and lower SSI were identified as the tolerant genotypes. For further evaluation, biplot was used. Four genotypes including No. 1, 2, 3, 5 and 14 were identified as tolerant genotypes and STI, GMP, MP indices were determined as suitable indicas in screening for drought tolerance.