Division of Genetics, Indian Agricultural Research Institute, Delhi-12
Eleven strains with H. 14 as check, were grown in a replicated randomized block trial in the Botany Division fields in 1963. Observations were recorded on seven characters and phenotypic and genotypic variances and covariances, heritability, phenotypic and genetic correlations and selection scores were calculated.
Boll number was positively correlated with seed-index and negatively with boll weight and ginning per cent. Boll weight had high positive correlation with ginning per cent. and a low correlation with lint index. Halo-length had a high positive correlation with seed-index and a negative correlation with ginning per cent. and with lint-index. Ginning per cent. and seed-index were negatively correlated.
It has been shown that in spite of negative associations, substantial scope exists for improvement in yield through simultaneous improvement in boll number, boll weight and ginning per cent., as well as for a simultaneous improvement in halo-length and ginning per cent.
Formulation of discriminatory selection scores based on components of yield as well as those of fibre-quality have been shown to be useful in isolating superior strains.
