粘质沙雷氏菌PS-1菌株对甜菜夜蛾幼虫中肠结构及消化酶活性的影响  

Effects ofSerratia marcescens PS-1 bacterial strain on structure of the midgut and digestive enzyme activities of Spodoptera exigua(Hünber)larvae

作　　者：赵晓峰[1] 向亚林[2] 凌冰[1] 许小霞[1] 张茂新[1] 

机构地区：[1]华南农业大学农学院,广州510642 [2]揭阳职业技术学院生物工程系,广东揭阳522000

出　　处：《环境昆虫学报》2017年第3期533-538,共6页Journal of Environmental Entomology

基　　金：广东省科技计划项目(2013B090700009-03;2014A020208106)

摘　　要：粘质沙雷氏菌Serratia marcescens PS-1菌株是从罹病黄曲条跳甲幼虫体内分离获得的病原菌,它对甜菜夜蛾Spodoptera exigua幼虫有显著的胃毒作用。为了明确PS-1菌株的杀虫机理,本文测定了甜菜夜蛾幼虫取食了含PS-1菌株的人工饲料后中肠蛋白酶和淀粉酶的活性,采用组织切片和透射电镜观察研究了甜菜夜蛾幼虫感染PS-1菌株后中肠肠壁细胞结构的变化。结果表明:甜菜夜蛾感染了PS-1菌株后,中肠蛋白酶和淀粉酶的比活力显著降低。对感染了PS-1菌株的甜菜夜蛾幼虫中肠的组织病理学研究发现,中肠整个围食膜被破坏消失;细胞明显伸长,变形;细胞间隙增大,细胞脱落。进一步的透射电镜观察发现中肠细胞的微绒毛脱落,内质网消失,细胞质空泡化。推测,粘质沙雷氏菌PS-1菌株对甜菜夜蛾幼虫的毒杀作用机制之一与消化酶活性抑制和中肠组织病变有关。Serratia marcescens PS-1 bacterial strain with high infectivity was isolated from the natural death larvae of Phyllotreta striolata. It has high effect of stomach toxicity against the Spodoptera exigua（ Hünber）larvae. In order to define the insecticidal mechanism,we measured the effects of S. marcescens oral infection on the activity of proteinase and amylase,and the ultrastructure of the midgut of S. exigua. The results showed that the activities of midgut proteinase and amylase were significantly decreased after PS-1infection. According to the histopathologic data,we found that the peritrophic membrane structure of infected larvae was seriously damaged. Intestinal epithelial cells were massively dead and compensatory proliferation. Furthermore,the infected midgut epithelial cell displays translucent vacuoles evocative of cellular stress. The results indicate that S. marcescens kill the larvae of S. exigua by inhibition of digestive enzyme and the destruction of the midgut.

关 键 词：甜菜夜蛾 粘质沙雷氏菌PS-1菌株 胃毒作用 酶活性抑制 组织病变 

分 类 号：S433.5[农业科学—农业昆虫与害虫防治] Q935[农业科学—植物保护]