Evaluation of indigenous and introduced bivoltine silkworm hybrids

Abstract

The present investigation was carried out to evaluate thirty-one silkworm bivoltine hybrids including control by involving full diallel set of six bivoltine breeds (ND2, ND3, NSP, U1, CSR2 and JD6) in a complete randomized design (CRD) along with ruling bivoltine hybrid, CSR2 × CSR4. Thirty-one treatments including control were replicated thrice with 200 worms per replicate post IIIrd moult. Observations were made on fifteen economically important traits namely; fecundity, hatching percentage, brushing percentage, weight of 10 mature larvae, larval survival, cocoon yield per 10,000 larvae (by weight and by number), good cocoon, pupation, single cocoon weight, single shell weight, shell ratio, total filament length, non-breakable filament length and filament size. Based on the cumulative E.I. values for fifteen commercial characters, ranking of hybrids was conducted and eight hybrids viz. ND2 × CSR2, ND2 × NSP, ND3 × NSP, ND2 × ND3, ND3 × CSR2, NSP × JD6, ND3 × JD6 and NSP × CSR2 qualified E.I. value > 50. Three hybrids viz., ND2 × CSR2 ranked 1st (55.53) followed by ND3 × NSP (55.33) and ND2 × NSP (53.93) are recommended as promising and heterotic hybrids to be exploited at commercial level after multi location trials.