Evaluation of Genetic Parameters and Combining Ability for Drought Tolerance in Cotton (Gossypium hirsutum)

Abstract

Global climate change especially water shortage and heat waves have drastically reduced cotton production. It is necessary to develop climate resistant coupled with high yielder cotton varieties suitable for various environments. For this purpose, ten cotton verities with different morphological, yield parameters, and drought tolerance/susceptibility were selected and hybridized using line × tester mating design. To study the inheritance pattern, twenty-five combinations along with their parents were grown in the field following augmented design with two different treatments i-e normal and water-deficit. Under stress environment, the GCA variance (σ2 gca) was higher than the SCA variance (σ2 sca) for CLCuD, number of bolls, boll weight, seed index, fiber length, and micronaiere value that shows additive type of gene action of investigated traits.  Line L5 (VH-327), tester T5 (FH-Lalazar) and crosse 18 (L4 x T3) and cross 21 (L5 x T1) performed best for yield and yield contributing traits under water deficit condition environment. Cross 18 (L4 x T3), 21 (L5 x T1) and 22 (L5 x T2) had the higher SCA for the bolls number and cotton yield (15-20% higher from parents) both under normal and water deficit condition. Both under normal and water deficit condition, the best-performing genotypes and combinations (15 to 20% increase in seed cotton yield) may be used in the cotton breeding program to enahance the seed cotton yield and drought tolerance.