Evaluation of Genetic Divergence in Asiatic Cotton

A set of 64 genotypes of G. arboreum were evaluated for their genetic diversity based on various quantitative traits such as seed cotton yield, boll weight, bolls/plant, lint percentage, lint yield, seed index, seeds/locule, days to 50% flowering, days to boll opening, plant height, chlorophyll content, leaf area index, lint index, span length, fibre strength, fibre fineness etc. The genotypes were grouped into six clusters on the basis of Mahalanobis D2 analysis. Maximum (97.85) and minimum (32.59) inter-cluster distances were observed between clusters I and V; and II and III, respectively. Intra-cluster distance values ranged from 0 (clusters V, VI) through 30.68 (cluster I). No association between genetic diversity and eco-geographical origin of the genotypes was observed. Similarly, several morphological traits such as plant body colour, petal colour, leaf shape, presence/absence of leaf nectary did not have any influence on the clustering of cotton genotypes. Some of the lines identified in this study may form part of the core collection of desi cotton. Potential donors may be selected from this set of desi cotton genotypes for use as parents for the development of varieties with desirable combination of characters.