棉铃虫核型多角体和质型多角体在宿主昆虫继代后的毒力分析与比较

The Analysis and Comparision on Virulence of HaNPV and HaCPVafter Serial Passages in Homologous Host Insects

以３龄健康棉铃虫幼虫为供试昆虫，测定棉铃虫核型多角体和质型多角体在幼虫体内分别连续继代后的毒力变化。就质型多角体而言，不论是病毒的致死剂量（ＬＤ）还是致死时间（ＬＴ）均随着继代次数的增加而升高，继代１０次后的病毒致死活性平均丧失５９．３％，与未经继代的病毒相比．ＬＤ＿（５０）增加１０３倍，ＬＴ＿（５０）平均延长４．４３５ｄ；而核型多角体在继代过程中的毒力未见显著变化，提示核型多角体与质型多角体在宿主昆虫内连续继代的遗传学行为有可能不同。

Taking he healthy cotton bollworm(Heliothis armigera)of the third instar astest insects,the virulence changes were investigated after serial passages of Heliothisarmigera nuclear polyhedrosis virus(HaNPV)and Heliothis armigera cytoplasmic polyhe-drosis virus(HaCPV)in the homologous host larvae. The results indicated that bothlethal dose and lethal time of HaCPV was increased along with addition-or passages,meanwhile,the relative lethal activity lose 59.3%on average,The median lethal dose ofHaCPV added to 103 times and median lethal time delayed 4.435 days in comparision withHaCPV for no passage(primary viruses).The virulence of HaNPV after passages did notshow obvious change. These results suggested that the genetic action of HaNPV andHaCPV for serial passages in hostcould have the certain difference.