Field experiment was conducted in twenty hybrids synthesized with the use of nine parents (four lines and five testers in ‘Line x Tester mating design) along with a check variety ‘MDU 1’ to estimate the magnitude of economic heterosis for exploitation of hybrid vigour of crosses for higher yield. Three traits viz., plant height, days to 50 % to flowering to which negative heterosis is desirable for early maturation of crop. Based on experimental results of this investigation four crosses viz., ACM-16-017 x VBN8, ACM-16-017 x KKM1, ACM-16-014 x VBN8 and ACM-16-014 x KKM1 had exhibited higher positive significant standard heterosis for yield and yield attributing traits in positive direction and negative heterosis for two traits viz., days to 50 % flowering and pods per plant. The presence of magnitude of standard heterosis was higher in these crosses for yield and yield attributes. Hence, exploitation of hybrid vigour may be achievable in these crosses which might be helpful in the improvement of this crop.

The genetic variability present in the available germplasm may be utilized either for direct selection or for hybridization programme. The experimental material comprised of four F2 populations along with respective parents of crops. This study was carried out in the kharif 2015-16 at Agricultural Research Station, Hebbali, UAS, and Dharwad. All the selected three characteristics (seed cotton yield per plant, number of bolls per plant and boll weight) of F2 populations of four promising hybrids showed the greater phenotypic coefficient of variation (PCV) values than the genotypic coefficient of variation (GCV) values, alluding to influence of environment on the expression of these traits. Among the studiedF2 hybrid, HBS1 X Suvin (82.14% & 93.63%) showed the highest GCV and heritability value in all three characters, respectively. Simultaneously the cross FQT-37 x SB-YF-425, showed 82.14%, and 88.47% heritability in two characters i.e. seed cotton yield per plant and number of balls per plant respectively. High heritability was recorded for all the three traits and this high heritability was coupled with high genetic advance indicating that selection can be done based on the mean performance for the respective traits. The highest number of transgressive segregants was recorded in the F2 generation of cross FQT-37 x SB-YF-425 (28 nos.) followed by HBS-1 x Suvin (23 nos.) and FQT-26 x Suvin (21 nos.) for the trait, seed cotton yield. These selected transgressive segregant plants can be advanced to further generations to help in isolating and stabilizing superior genotypes. All the characters i.e. seed cotton yield per plant, number of bolls per plant and boll weight showed high heritability with high genetic advance that revealed the substantial contribution of additive gene action in the expression of traits, which is most valuable in further selection.