Genetic variability heritability and genetic advance studies in cotton (Gossypium hirsutum l.)

The present experiment was carried out at research farm of Cotton Research Station, Srivilliputtur, to determine genetic variability, heritability and genetic advance estimates in upland cotton. The analysis of variance involving a set of fourty two improved hirsutum genotypes received from various research institutes under AICRP on Cotton for eleven characters viz., Days to 50% flowering, Plant height, Number of monopodia per plant, Number of sympodia per plant, Number of bolls per plant, Boll weight, Ginning percentage, Upper Half Mean Length, Bundle strength, Micronaire value, and Seed cotton yield (kg/ha) revealed highly significant mean sum of squares for all the characters indicating greater diversity among the genotypes. The value of Phenotypic Coefficient of Variation (PCV) is greater than Genotypic Coefficient of Variation (GCV); it means that the apparent variation is not only due to genotypes but also due to influence of environment. The difference between the estimates of PCV and GCV were low for all the characters except number of monopodia per plant, number of sympodia per plant and number of bolls per plant thereby indicating that lesser role played by the environment in the expression of these characters. The traits like Days to 50% flowering, Plant height, Boll weight, Seed cotton yield (kg/ha), Upper half mean length, Micronaire value and Bundle strength exhibited high broad sense of heritability and moderate sense of heritability was observed for Number of monopodia per plant, Number of sympodia per plant, Number of bolls per plant and Ginning percentage. High heritability coupled with high genetic advance as a percent of mean was recorded for boll weight, seed cotton yield and micronaire value indicated the major role of additive gene action in the inheritance of these characters. Thus, these characters may serve as an effective selection parameter during breeding programme in the upland cotton.