Heritability and selection response in segregating generations of upland cotton.

Abstract

Heritability (b.s), genetic advance, phenotypic and genotypic vari- ance for different quantitative traits is important in determining the effective- ness of selection. In this study the potential effectiveness of selection in parents and their F 2 and F 3 progenies of Gossypium hirsutum for plant height, sympodia/ plant, bolls/plant, boll weight, seed index and seed cotton yield/plant was deter- mined. It was found that all the populations alongwith parents differed signifi- cantly (P < 0.01) and exhibited genetic variability among the genotypes for all the traits except sympodia/plant. Genetic parameters computed through variance com- ponents method show that all the traits were highly heritable in F 2 and F 3 genera- tions except sympodia/plant, indicating quantitative pattern of inheritance, of- fering better chances of selection for these traits in F 2 and F 3 generations. The traits namely plant height, bolls/plant and seed cotton yield/plant displayed high heritability (72.97 - 75.55%) with remarkable genetic advance (112.46 - 357.01%) indicating that these traits were predominantly governed by additive gene effects and direct selection may be effective. Boll weight and seed index exhibited low genetic advances irrespective to their high heritability estimates, probably due to non-additive gene effects, developing transgressive segregants through hybrid- ization is suggested. However, hybridization system, which exploits both fixable and non-fixable components, simultaneously, could be useful in the genetic im- provement of yield and yield components in upland cotton.