Estimation of the Effects of Genes Controlling Seed Cotton Yield and Yield Components in Upland Cotton under Salinity and Normal Conditions

In order to estimate heritability of seed yield and yield components in cotton, a diallele cross method was attempted. Ten genotypes including 6 F1 progenies and parents were grown in Kashmar Cotton Research Station (non-saline location) and Saadaldin region, 50 kilometers far from Kashmar (Saline location), in a randomized complete block design with three replications in 2003. Diallel analysis was done based on Griffing method II for seed cotton yield, boll seed cotton weight, percentage of earliness and the number of plants in plot. Results showed that the variance of genotypes was significant only for boll seed cotton weight in non stress environment and for seed cotton yield and number of plant per plot in stress condition. The effect of general combining ability of boll seed cotton weight was significant in non-stress environment. Seed cotton yield and plant number per plot, were significant in salinity condition.The effect of specific combining ability for boll seed cotton weight in non-stress environment and the plant number per plot in stress condition were significant. It was also significant for seed cotton yield in stress condition. Diallel analysis showed that both additive and non additive genes effect had a role in controlling the mentioned traits. Combining diallel analysis indicated that additive variance was important for boll seed cotton weight, seed cotton yield and the number of plant per plot. Broad sense heritability was high for all traits in both conditions, whereas narrow sense heritability varied from low to mediate in both conditions.