Genetic variability and heritability estimates in F2 populations of intra hirsutum for various traits

Abstract Plant breeders are more interested in genetic variance rather than phenotypic variance because it is the only portion of total phenotypic variance which is amenable to selection and brings about further improvement in the desirable characters. Therefore the current investigation was laid out in randomized complete block design with three replications during the season 2020 at the Cotton Research Institute, Tandojam. The mean square of genotypes differed significantly for the characters number of days to 1st boll formation, days to 1st boll opening, boll formed at 90 days after sowing, bolls plant− 1, boll weight (g), seed cotton yield plant− 1 (g) and GOT (%).while plant height, sympodial branches plant− 1 and staple length were non-significant. The result further related that among the parental lines, CRIS-508 takes maximum days to 1st boll formation, 1st boll opening and GOT (%).The CRIS-510 gave highest sympodial branches plant− 1, Bakhtawar showed taller plants and bolls plant− 1, Mehran exhibited maximum boll formation at 90 days after sowing, boll weight (g), seed cotton yield and staple length. Among the F2 progenies Mehran x Koonj, Mehran x CRIS-508 and Bakhtawar x CRIS-508 recorded better mean performance for most of the traits. The F2 population like Bakhtawar x CRIS-508 showed maximum (77.80%) for days to 1st boll opening, (82.03%) heritability bolls formed at 90 days after sowing (84.89%) for staple length. Mehran x Koonj expressed maximum (88.78%) heritability for sympodial branches plant− 1 and (90.52%) for GOT (%) could best be discovered in successive groups of selfing to expand these characters. Koonj x CRIS-510 gave high (82.83%) heritability for plant height, and (55.67%) bolls plant− 1 and Bakhtawar x CRIS-510 showed high heritability for seed cotton yield and could serve potential segregating populations in further selfing generations.