ESTIMATES OF GENETIC VARIABILITY FOR COMMERCIAL QUANTITATIVE TRAITS AND SELECTION INDICES IN BIVOLTINE RACES OF MULBERRY SILKWORM (BOMBYX MORI L.)

Abstract

Genetic variability for economically important quantitative traits and selection indices of 46 bivoltine races of mulberry silkworm (Bambyx maTi L.) were estimated. High values of heritability along with genotypic and phenotypic coefficient of variations for filament length, single-shell weight and single- cocoon weight showed that the above characters are under genetic control. The correlations between single-cocoon weight and single shell weight as well as single-shell weight and shell ratio were highly significant. The selection index programme based on discriminant function analysis resulted into five clusters of 10 genotypes with lower index values for utilisation in hybridization and breeding programmes.