Genetic diversity analysis of upland cotton (Gossypium hirsutum L.) genotypes using cluster analysis

The D2 statistic enables the evaluation of genetic diversity among numerous genotypes and aids in selecting genetically distinct parents for hybridization programmes. The present research work on genetic diversity involved 56 genotypes of upland cotton, evaluated in alpha lattice design with two replications and data was collected on 19 characters. Multivariate analysis revealed substantial genetic diversity among the 56 genotypes evaluated. Using Tocher’s method in D2 analysis, the genotypes were classified into six distinct clusters. Among the traits studied, total seed cotton yield plant-1 contributed more towards genetic divergence followed by seed cotton yield plant -1 at 140 days after sowing, proline content, ginning out turn and seed index. The cluster II had highest (19) number of genotypes followed by cluster I (16) genotypes, cluster III (10) genotypes and cluster IV (8) genotypes. For most of the traits inter cluster distances were higher than intra cluster distance which indicates considerable diversity among the genotypes. The greatest inter-cluster distance was observed between clusters IV and VI followed by clusters V and VI and clusters II and IV indicating that crossing genotypes from these clusters could generate a broad range of variation in the segregating population and potentially produce hybrids with high heterosis.