Variability, heritability and genetic advance for yield and quality components in interspecific F1 hybrids of cotton

Assessment of genetic variability using appropriate parameters like phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), heritability (h2), and genetic advance (GA) are really necessary to start an efficient breeding program. Cultivated tetraploid cotton (G. hirsutum x G. barbadense) hybrids were subjected to variability evaluation, heritability and genetic advance in a randomized complete block design during the summer 2016. The analysis of variance was highly significant for the eighteen characters studied. Elongation % recorded the highest coefficient of variation followed by number of seeds/boll, boll weight, lint index and number of monopodia. Phenotypic coefficient of variation (PCV) recorded higher values than their corresponding genotypic coefficient of variation (GCV) for all the characters, this indicated obviously the presence of environmental interaction in phenotypic expression of the traits. Number of monopodia had the highest PCV and uniformity ratio recorded the least. The highest GCV was recorded by number of monopodia followed by seed cotton yield/plant while least GCV was recorded by days to first bursting followed by 2.5% span length and elongation %. Heritability was expressed very high by seed cotton yield followed by number of bolls/plant. Other characters had high heritability except elongation %, 2.5% span length and days to first bursting which recorded low heritability. The most favourable selection response was demonstrated by number of monopodia and micronaire value. Number of monopodia, micronaire value, lint index and boll weight had demonstrated an additive gene effects by having high heritability and high genetic advance over mean, directional selection would have positive effect for their genetic improvement.