粉质拟青霉侵染菜青虫致病过程的研究

Studies on pathogenesis of Paecilomyces farinosus infecting Pieris rapae (Linnaeus)

应用电镜扫描技术观察了粉质拟青霉 990 5菌株对菜青虫的侵染过程 ,根据感病虫体外部症状进行病情分级 ,并应用石蜡切片法观察了不同感病程度菜青虫虫体内部的组织病变情况。结果表明粉质拟青霉菌丝侵入菜青虫血腔后首先侵入脂肪体细胞 ,并证实脂肪体是粉质拟青霉繁殖最多的部位。致死状态表现为 :1级 ,感病菜青虫只是体壁出现病变 ,2级 ,菜青虫已死亡 ,体内各组织均发生不同程度的病变。 3级 ,菜青虫体内几乎所有的组织器官都已解体。

Infection process of Paecilomyces farinosus strain 9905 to Preris rapae was observed by techniques of scanning electron microscopy. The histopathological changes of P. rapae infected by P. farinosus and external symptoms of sick insects were studied based on pathogenic grades and wax cutting. The results showed that the fat body by hyphae was firstly infected and it was the most serious site for reproduction of P. farinosus. The pathogenic grades can be classified as grade 1-the integument of infected insects P. rapae, was destroyed. Grade 2-infected insects were dead and all tissues were infected. Grade 3-all tissues and organs of infected insects were disintegrated.