Genetic basis of heterosis for seed cotton yield, fibre and biochemical traits in cotton through line × tester analysis

Abstract

The present study was undertaken to assess heterosis for seed cotton yield, yield-contributing traits, fibre quality and biochemical characters in upland cotton (Gossypium hirsutum L.) using a Line × Tester design. Four lines, seven testers and their twenty-eight F₁ hybrids, along with the standard check GN.Cot.Hy-18, were evaluated in a Randomized Block Design with three replications during kharif 2024. Analysis of variance revealed significant genetic variability for all traits except seed index. Among the hybrids, 76-IH-20 × GISV-382 exhibited significant heterobeltiosis for seed cotton yield, while BC 68-2 × GISV-399 and 76-IH-20 × GISV-382 recorded the highest significant standard heterosis over the check. These hybrids also expressed desirable heterosis for major yield components such as bolls per plant, boll weight and ginning outturn, along with notable heterotic effects for fibre and biochemical traits. The hybrids BC 68-2 × GISV-399, 76-IH-20 × GISV-382, 76-IH-20 × GISV-399 and GSHV-112 × GISV-399 were identified as promising for exploitation of heterosis in cotton breeding programmes.