Relative yield and fibre properties of parents, F1 and F2 hybrids were compared. The variances among the genotypes were significant for yield, lint %, fibre length and fibre uniformity. Similarly, variances for all the four traits were significant among parents, F1 and F2 groups. In orthogonal contrast comparison, F2 hybrids expressed higher variance for yield and lint percent whereas for fibre length, F1s presented more variance and in fibre uniformity, parental lines have shown greater variance than the other two groups of genotypes. Orthogonal contrast comparisons were also made where parents versus F1 and F2 hybrids expressed more variance than F1 versus F2 hybrids for all the traits except fibre length. In relative performance, F1 and F2 hybrids, on an average produced 36.4 % and 20.1 % respectively, more yield than the parents. Though, F2 hybrids have shown 12.0% inbreeding depression, nevertheless six of the 12 F2 hybrids gave higher yield than F1 hybrids showing that potential in F2 hybrids exists to replace F1 hybrid crop development. Accordingly in Lint %, F1 and F2 hybrids were higher than parental lines but surprisingly F2 and not the F1s expressed 9.0 % and F1s only 3.0 % heterosis against parents, consequently F2s have shown 6.0% higher lint % than even F1 hybrids. In fibre length, F1s have demonstrated 3.0 % increase over parents whereas F2s were equal to parents. Both F1 and F2 gave 4.1% more uniform fibre over the parental lines.
Mohammad Jurial Baloch , Abdul Rahim Lakho , Hidayatullah Butto and Rehmatullah Rind , 2002. Seed Cotton Yield and Fibre Properties of F1 and F2 Hybrids of Upland Cotton. Asian Journal of Plant Sciences, 1: 48-50.