Breeding Drought Tolerant Cotton; With an Emphasis on Within Boll Yield Components

Evolution of low moisture stress tolerant genotypes of cotton is a dire need of the time for sustainable/increased production of cotton in Pakistan. A study was conducted to estimate the varietal differences and genetic control of various within boll yield components and fiber quality traits under normal and moisture stress conditions. Five parents viz; PB-39, MNH-886, MNH-147, CIM-598, BH-95 and their ten direct crosses were grown in field in split plot arrangement under randomized complete block design with two replications. Analysis of variance revealed significant differences between the two treatments (normal and moisture deficit) and among the fifteen genotypes for all the recorded traits including bolls number per plant, weight per boll, seed cotton yield per plant, GOT, seeds number per boll, seeds mass per boll, lint mass per boll, fiber length, fiber strength and fiber fineness. Treatment × genotype interaction was also significant for all the traits except fiber fineness. Variance due to GCA and SCA were significant for most of the traits; however magnitude of dominance variance was higher than additive variance indicating prevalence of non-additive genetic control for all the traits under both the conditions. The phenotypic expression of all the genotypes varied greatly under the two growing conditions.