Genetic diversity analysis in American cotton (Gossypium hirsutum L.)

Abstract

Genetic divergence was studied among 50 genotypes of American cotton (Gossypium hirsutum L.) using Mahalanobis D2 statistic and principal component analysis. On the basis of D2 statistic, 50 genotypes were grouped into 8 clusters and PCA identified six principal components which explained 81.99% of the total variability among the genotypes. Based on intraand inter-cluster distance among the groups, it is suggested to make crosses between the genotypes of cluster VI (ARBH 1402) and cluster VII (HYPS 152), cluster I (SSGR 105) and cluster VIII (L 788), cluster I (SSGR 105) and cluster IV (L 799) and between cluster V (GJHV 497) and cluster VIII (L 788) for heterosis breeding. Divergence studies indicated that geographical diversity is always not necessarily associated with the genetic diversity. Multivariate analysis revealed the presence of maximum divergence among L 788, HS 294, MCU 5, HYPS 152 and GISV 267 reporting their parental eligibility in exploitation of hybrid vigour.

Keywords

• genetic divergence
• d2 statistic
• clusters
• gossypium hirsutum l.