Assessment of genetic variability in cotton (Gossypium hirsutum L.) genotypes

Abstract

The evaluation of phenotypic characteristics is critical in the selection of top cotton lines. Cotton breeders want to use a variety of genotypes in hybrids to segregate for desired characteristics while also allowing for selection and genetic gain. Breeders can use phenotypic diversity information to aid in parental selection. In this context, a set of 12 advance cotton lines were evaluated for genetic diversity at Cotton Research Institute, Tandojam during Kharif season 2020. The experiment was laid out in randomized complete block design with three replications, while seven agronomical traits were included in the experiment. The mean squares of genotypes were significantly differences (P<0.05) for all studied traits, representing that genetic diversity is existed in these cotton germplasms for further utilization. Considering the agronomic performance, the genotype B-2 was on top in average values for plant height (174.40 cm), bolls plant-1 (42.067), seed cotton yield plant-1(139.34 g), GOT% (37.800%) and staple length (28.00 mm), hence indicates its valuable breeding resources for future cotton breeding. The greater genetic distance of 92.683 was found between B5 and B2 genotypes, revealing that this pair may be used in hybridization program for vigorous hybrid production and better selection in subsequent generations. The variance percentages for the first, second, and third principle components were 42.70, 23.10, and 17.20, respectively; the first three components contributed 83.00 percent of the variation for genotypes, which is high enough for cotton crop improvements. The cotton genotypes were divided into three categories based on phenotypic data. The many groups obtained might be beneficial in generating cotton genotypes with a variety of characteristics and diversifying the cotton gene pool