Nucleopolyhedrosis is the most common and serious disease in silkworm rearing. Breeding of new silkworm varieties with high resistance to nucleopolyhedrosis plays an important role in stable sericultural production. With 2 silkworm varieties Jingsong and Haoyue of excellent quality and high yield as the recipients, and silkworm strain N carrying resistance genes against Bombyx mori nucleopolyhedrovirus(BmNPV) as the donor, a new variety with the disease resistance gene was bred using hybridization, back crossing(the recipient variety as recurrent parents performed 4 rounds of back-crossing) and dominant gene homozygous fixation technique. Jingsong N×Haoyue N(named as Huakang 3) with excellent quality, high yield and strong resistance to BmNPV was picked up through subsequent systematic selection to improve and stabilize the comprehensive economic character of backcrossed generation. BmNPV resistance of this new variety was 10 000 times higher than that of the original variety Jingsong×Haoyue, while its comprehensive economic character is similar to that of the original variety. Huakang 3 has been approved by Sichuan Provincial Silkworm Variety Approval Committee in March 2018, and it is suitable for rearing in the areas alongside the Yangtze River and the Yellow River and in other areas.
Acta Sericologica Sinica
Disease resistance breeding