Study of Heterosis, Combining Ability and Parental Diversity for Seed Cotton Yield and Contributing Traits using Diallel Data in Cotton (G. hirsutum L.)

Abstract

Background: Combining ability and parental diversity contributes directly to improve the heterotic potential. The experiment was aimed to study the parental diversity and its contribution to heterosis and to get an idea if parental diversity has any influence on the combining ability of the parental lines.Methods: The field testing was carried out during 2017-18 at three locations comprises, Sirsa, Bathinda and Abohar. Total eight parents were crossed in diallel manner to produce 56 combination excluding eight parental genotypes using full diallel. All the hybrids and parental lines were tested using RBD at the selected locations and the mean of these three locations data was used to study the relationship. Genetic relatedness of the parents was studied using 20 SSR markers and the distance/similarity matrix was developed using Jaccard coefficient method. Result: Genotypes showed significant (p≤0.01) differences for mean squares values for all the traits under study. F-2228, F-2164 and LH-2108 were the parents with best general combining abilities. Parental lines RS-2013 and RST were found to be the most divergent lines. The best F1 hybrids such as RST-9 x F-2164, LH-2076 x RST-9 and LH-2076 x RS-2013 comprised of diverse parents produced high heterosis for seed cotton yield. Among all the traits under study the maximum heterosis was received for seed cotton yield with a max gain of 126.8% over the mid parent.