NATURE OF GENETIC DIVERGENCE AMONG SOME COTTON GENOTYPES

Abstract

Inherent divergence and parenthood of germplasm could play an important role in genetic improvement of cotton. The present investigation was conducted to assess the genetic divergence among fourteen locally cotton genotypes and six exotic genotypes using multivariate Mahalanobis D2 statistics and metroglyph analysis. The results showed highly significant differences among these genotypes for all the studied quantitative characters. The Mahalanobis D2 statistics showed that the dissimilarity coefficients were significant and highly significant, which ranged from 3.263 to 190.89, indicating highly genetic divergence for these cotton genotypes. Seed cotton yield and fiber strength were account about 83% of total genetic divergence. The metroglyph analysis grouped these genotypes into eight different clusters based on seven quantitative cotton characters. The inter-cluster D2 values ranged from 11.381 to 178.902 between these groups, while, the intra-cluster D2 values ranged from 3.263 to 47.806 within each group. On the basis of this grouping, it was concluded that hybridization between genotypes of different clusters might be expected to give new genetic recombinants for different economic characters. These informations could be utilized for hybridization between distinct genotypes to increase genetic cotton variability.