Studies on heterosis for yield and fibre quality traits in GMS hybrids of upland cotton (Gossypium hirsutum L.).

Forty four cotton (Gossypium hirsutum L.) hybrids were produced from a line x tester crossing programme with 15 parents (four lines and eleven testers). The primary objective of this study was to determine the useful heterosis in Gossypium hirsutum for seed cotton yield, its component traits and fibre quality parameters in 44 GMS (genetic male sterility) based cross combinations. The analysis of variance indicated that the mean squares of genotypes were significant for seed cotton yield (kg/ha), monopodia, sympodia and bolls/plant, boll weight (g), GOT (%), micronaire value and strength (g/tex) except 2.5 per cent span length (mm) indicated the presence of variability among hybrids and their parents. Studies revealed that none of the cross combinations exhibited significant heterosis over the check hybrid CSHH 198 for seed cotton yield, number of bolls per plant, boll weight and sympods/plant and micronaire value. Significant heterosis monopods/plant, seed index, ginning percentage, 2.5 per cent span length and fibre strength were detected over the conventional check hybrid CSHH 198. For number of monopods in GMS 17 x CISV-1 (81.1%), seed index in GMS 20 x Bikaneri narma (15.9%), ginning percentage in GMS 17x 007 DA (10.4%) showed the highest and significant positive heterosis over the conventional check hybrid CSHH 198. For quality traits, 2.5 per cent span length in GMS 26 x 006 DA (7.4%) and for fibre strength GMS 21 x 006 DA (13.4%) showed the highest and significant positive heterosis over the conventional check hybrid CSHH 198. The cross combination involving female parent GMS 21 and male parent 006 DA. Bikaneri narma recorded the significant positive heterosis for most of the characters so could be exploited in producing hybrid cotton.