暗黑鳃金龟幼虫取食Bt菌株HD8E和HD8G后的中肠细胞病理变化

Pathological changes in the midgut of Holotrichia parallela larvae after feeding on HD8E and HD8G

【目的】暗黑鳃金龟Holotrichia palallela Motschulsky的幼虫(蛴螬),是小麦、花生、大豆、玉米、高粱、马铃薯等作物的重要地下害虫。本研究为暗黑鳃金龟幼虫的生物防治奠定了基础,并为抗虫转基因作物的研究提供优良的候选基因。【方法】将HD8E和HD8G两个Bt株系的晶孢悬液饲喂蛴螬后,利用透射电子显微镜对蛴螬中肠进行病理性观察,利用解剖镜观察蛴螬肠道内容物。【结果】观察结果显示蛴螬的中肠组织出现微绒毛脱落、环肌和纵肌肌纤维降解、中肠细胞间隙扩大、细胞内质网肿胀断裂、线粒体变形等现象。【结论】HD8E和HD8G两个Bt株系可以导致蛴螬中肠组织结构发生明显的病变,且可明显地抑制暗黑鳃金龟幼虫的取食行为。

[Objectives] Holotrichia palallela Motschulsky （Coleoptera： Melolonthidae） is an important underground insect pest that seriously damages wheat, peanut, soybean, corn, chinese sorghum, and potato, crops. This paper lays the foundation for the biological control of H. palallela larvae with the Bt strains HD8E and HD8G, and may provide some excellent candidate genes for the development of insect-resistant, genetically modified, crops. [Methods] Pathogenic changes in the midgut of grubs after ingestion of HD8E and HD8G were observed using transmission electron microscopy and an anatomical lens, respectively. [Results] Pathogenic changes in the midgut of H. palallela larvae included the shedding of microvilli, degradation of longitudinal and circular muscles fibers, expansion of the intercellular space, swelling and breakage of the endoplasmic reticulum and mitochondrial cyclization. [Conclusion] The two Bt strains HD8E and HD8G caused obvious pathogenic changes in the midguts of H. palallela larvae and visibly inhibited their feeding behavior.