Genetic Analysis of Drought Tolerance in White Bean

A study was conducted to determine genetic control, GCA and SCA for yield and yield components in white bean (Phaseolus vulgaris L.). Five parents and 10 F1 hybrids were evaluated by diallel analysis using Griffing model 2 of method 2. The experiment was carried out in a randomized complete block design with three replications conducted in normal and water stress conditions in the Khompin National Bean Research Station in 2005. The results of analysis of variance under two conditions showed significant differences among all genotypes for most of the traits. GCA and SCA in the normal condition were significant for pods/plant, seeds/plant and seed yield. GCA for seed/pod was also significant. Therefore, additive and non additive effects were important in controlling these traits. In the water stress condition, GCA and SCA were significant for pods/plant and seed yield. The highest positive value of GCA in normal condition for yield and yield components was related to parent genotype KS 41107 and in water stress condition to the other parent cultivar Dehghan. Therefore, these parents could be used in breeding programs. Estimating of genetic parameters by Hayman method showed that dominance effect was more important than the additive effects for pods/plant, seed/plant and seed yield in the normal condition. Average degree of dominance for all traits was more than 1 except for 100 seed weight. Therefore, for these traits over dominance effect was identified.