家蚕对马尾松毛虫质型多角体病毒的敏感性

用虫体克隆技术，对马尾松毛虫质型多角体病毒湖南株（DpCPV-HN）进行了分离纯化，鉴定为质型多角体病毒1型。以家蚕春蕾×镇珠杂种F₁代及自交的F₂代4或5日龄幼虫进行毒力测定，以纯化的家蚕质型多角体病毒对F₁代幼虫的毒力测定为对照。结果表明：家蚕品种春蕾×镇珠对家蚕质型多角体病毒敏感，马尾松毛虫质型多角体病毒湖南株能引起其感染发病；马尾松毛虫质型多角体病毒湖南株感染家蚕品种春蕾×镇珠F₁代幼虫和F₂代幼虫28天后的半致死剂量（LD₅₀）分别为885个和18个CPB(质多角体)，前者为后者的49倍。马尾松毛虫质型多角体病毒湖南株感染后的家蚕，其结茧率、化蛹率、羽化率、全茧量、茧层量和单蛾产卵数均有所下降，全茧量、茧层量、茧层率和单蛾产卵数与病毒感染剂量之间无显著关联。

The sensitivity of Bombyx mori larvae to Dendrolimus punctatus cytoplasmic polyhedrosis virus

Dendrolimus punctatus cytoplasmic polyhedrosis virus strain Hunan (DpCPV HN) was cloned in vivo and identified as a type 1 cypovirus. Fourth\| or 5th day post hatching F 1 and F 2 silkworms from an generation F 1 that had previously been infected by DpCPV HN, and two other type 1 cypoviruses from Bombyx mori (BmCPV 1) and D. punctatus (DpCPV HN) were selected for the infection test. The results indicate that the breed of B. mori tested in this study was very sensitive to BmCPV 1, and could also be infected by DpCPV HN. Based on the accumulative total mortalities of F 1 and F 2 generations of B. mori infected by DpCPV HN over 28 days post infection,the 50% lethal doses (LD 50 ) of DpCPV HN of F 1 and F 2 generations were 885 and 18 CPBs respectively. Obviously, the F 2 silkworm larvae from DpCPV infected generation F 1 were more sensitive to DpCPV HN than those of the F 1 generation. However, the sensitivity of the F 2 generation to DpCPV HN was still inferior to that of the F 1 to BmCPV 1. To some degree, the ratio of cocoons,ratio of pupae,ratio of moths to pupae, cocoon weight, cocoon shell weight, ratio of cocoon shell weight, and number of eggs from single female moths of the F 1 and F 2 generations were affected after infection by DpCPV HN. The correlations between cocoon weight, cocoon shell weight, ratio of cocoon shell weight,number of eggs from single female moths of silkworms and inoculation doses of DpCPV HN were not obvious.