Vol. 12, Issue 7 (2023)

A study “Genetic diversity analysis in cotton using morphological traits (G. hirsutum L.)” was undertaken to estimate the degree of divergence among the 50 genotypes of upland cotton using multivariate Mahalanobis D2 statistics on the field of SDMVM’s college of agriculture, Paithan road, Aurangabad (MH). The analysis of variance revealed significant differences among 50 genotypes for all fourteen characters. This is also confirmed by Wilk’s criterion. The canonical analysis revealed that about 85.96 per cent of the total variation was accounted by the first six canonical roots. In vector I, number of monopodia per plant was important sources of variation. Whereas 2.5 per cent span length was important sources of variation in vector II. In vector III, number of bolls per plant, in vector IV seed index, in vector V, fibre strength and in vector VI, number of bolls per plant played important role in variation. Plant height, seed index and number of bolls per plant were contributing towards genetic divergence. By using Tocher’s method, all 50 genotypes were grouped into seven clusters. Cluster I had highest number of genotypes (19) followed by cluster III (14), cluster IV (8), cluster II (6) and cluster V, VI and VII represented by single genotypes. The maximum genetic distance was recorded between cluster V and cluster VII (D=9.66). By considering the mean statistical distance as a guideline to select the divergent genotypes, 18 cluster combinations were identified. The divergent parents selected from these combinations may yield better segregants in hybridization programme. However, when divergent parents are crossed, heterosis is not always found to occur. Therefore, while selecting the divergent parents from a particular cluster, the information on mean and standard deviation of the genetic variance among the divergent parents should be taken into consideration as practically suggested by Arunachalam and Bandyopadhyay (1984). Hence, on the basis of mean and standard deviation of parental divergence, 41 cross combinations out of 192 parental combinations have been finally suggested which are expected to yield desirable genetic gain in breeding programmes.