甘蓝夜蛾核型多角体病毒连续传代的研究

Serial Passage of Mamestra brassicae Nuclear Polyhedrosis Virus in Vitro

对甘蓝夜蛾核型多角体病毒（ ＭｂＮＰＶ） 在同源寄主细胞系ＮＥＡＵＭｂ９３１１０４（ Ｍｂ９３１１０４） 中的生长特性进行了研究。结果表明，无包涵体游离病毒（ ＭｂＮＰＶ＿ＮＯＶ） 在接种后１４ ｈ 达到吸收高峰，病毒滴度降到最低值５－７９ ×１０２ＴＣＩＤ５０／ｍ Ｌ，接种病毒９６ ｈ，病毒滴度达到最高值２－１３ ×１０５ＴＣＩＤ５０／ｍＬ，在ＮＯＶ（ｎｏｎｏｃｃｌｕｄｅｄ ｖｉｒｕｓ） 连续传递２０ 代的过程中，ＭｂＮＰＶ＿ＮＯＶ 毒力随传递代数的增加而减低，并且多角体的毒力也发生了显著的变化，前几代能使甘蓝夜蛾幼虫死亡率在９０ ％ 以上，传递到１５ 代以后产生的多角体对甘蓝夜蛾的幼虫几乎没有毒力。

The long term continous replication of Mamestra brassicae nuclear polyhedrosis virus(MBNPV) in homologous host cell line NEAU MB 931104 was studied. The growth curve indicated that nonoccluded virus(NOV) was present on the culture medium 14 h postinfection(Pi) and reached a minimum titer 5 79×10 2TCID 50 /mL,when inoculate virus 96 h,reached a maximum titer of 2.13×10 5 TCID 50 /mL. The virulence of the virus produced on the cell line decreased with the increase of serial viral passage. MbNPV from different passage in vitro were diluted 8.0×10 5 PIBs/mL and reonates of M.brassicae were used in bioassays. When infecting larval mortality were 93.1% and 54.7% respectively, but for the polyhedra from the twentith passage had hardly virulence.