Sarial, A.K.Jain, Ashish2016-11-192016-11-192008http://krishikosh.egranth.ac.in/handle/1/86434The present investigation was undertaken to estimate standard heterosis with the objective of exploring possibilities of its commercial utilization and study of combining ability effects. The material for the present study comprised of 42 hybrids developed on three male lines (testers) using 14 female parents (lines) in a line x tester mating design along with their 17 parents (14 lines and 3 testers) and one standard check (HHH 223). The experimental material was grown at Research Area of Cotton Section, Deptt. of Plant Breeding, CCS HAU, Hisar, during Kharif 2007 in a randomized block design with three replications. Observations were recorded for ten characters namely, plant height, days to 50% flowering, boll number, boll weight, number of monopods, number of sympods, ginning out turn, seed index, lint index and seed cotton yield per plant. The standard heterosis was calculated over standard check HHH 223. Marked economic heterosis was observed for most of the characters studied. Among all the hybrids studied, cross combination RS 875 x HS 88 exhibited heterotic effects (49.46%) for seed cotton yield per plant followed by Machha early x HS 6 (40.23%), Tidewater 4 x HS 88 (36.28%) and HS 223 x HS 88 (35.93%). The magnitude of heterosis is reasonably high warranting their testing for commercial exploitation. Significant positive heterosis for boll number was also recorded in most of the promising hybrids. Combining ability analysis revealed the presence of both additive and non-additive variance where additive variance figured more prominent over non-additive variance for almost all the characters. In general none of the male or female parent showed high gca effects for all the traits studied. Among testers HS 88 was the best general combiner while among lines RS 875, HS 223 and HS 180 were promising parents that could be utilized for future breeding programs.enCotton, Yields, Heterosis, Sowing, Biological phenomena, Crossing over, Planting, hybrids, Additives, BeveragesThesis