Evaluation of bivoltine silkworm (Bombyx mori L.) breeds on survival against nuclear polyhedrosis virus (Grasserie) under temperate climatic conditions

Abstract

The present studies on the evaluation of different bivoltine silkworm (Bombyx mori L.) breeds on survival against Nuclear Polyhedrosis Virus (Grasserie), under temperate climatic conditions was carried out at College of Temperate Sericulture, SKUAST-Kashmir, Mirgund. Preliminary evaluation of ten silkworm genotypes viz., APS4, APS8, CS6, CSR2, CSR4, DUN-6, DUN-22, NB4D2, SH6 and SANISH8 revealed that APS8 and NB4D2 breed possessed highest tolerance while, CSR2 and CSR4 were highly susceptible to BmNPV Inoculation @ 20,000 PIB’S. The silkworm CSR4 showed drastic decrease in survival rate of (37.33%) in susceptible breed. However in tolerant breed APS8 recorded the survival rate of (72.67%). The maximum pupation rate of 91.36 per cent was recorded in case of NB4D2 and minimum pupation rate of 82.41 per cent was recorded in CSR2.