Genetic analysis of drought tolerance in upland cotton using diallel crosses

ten genotypes including six F1 progenies and their parents were grown in Kashmar CottonResearch Station in two separate experiments (non-stress and drought stress conditions), in a randomized complete block design with three replications. Diallel analysis was done based on Griffing’s method II for seed cotton yield, boll seed cotton weight, percentage of earliness, the number of bolls and height of plant. Results showed that the variance of genotypes was significant for boll seed cotton weight and height of plant in non-stress environment and for seed cotton yield and height of plant in stress condition. The effect of general combining ability of boll seed cotton weight and height of plant were significant in non-stress environment. Also it was significant for seed cotton yield and height of plant in drought condition. The effect of specific combining ability wasn’t significant for any trait. Diallel analysis showed that additive gene effect had an important role in controlling the mentioned traits. Combined diallel analysis indicated that additive variance was important for seed cotton yield and height of plant. Broad sense heritability was high for all traits in both conditions, whereas narrow sense heritability varied from low to high in both conditions.