家蝇不同虫态附着蜡蚧轮枝菌分生孢子能力及与其体表结构的关系
Adhesion capacities of Lecanicillium lecanii conidia on different insect states of Musca domestica and the relationship with their surface structures
-
摘要: 【目的】研究家蝇成虫、幼虫和蛹附着蜡蚧轮枝菌分生孢子的能力及与其体表结构的关系,为解释虫生真菌对同一昆虫不同虫态间的致病性差异提供科学依据。【方法】采用2种不同接菌方法(浸泡虫体法、喷雾虫体法),通过血球计测量家蝇3种虫态(成虫、幼虫和蛹)体表附着的蜡蚧轮枝菌分生孢子数,并利用扫描电子显微镜等显微技术观察3种虫态的体表超微结构及附着分生孢子情况。【结果】2种接菌方法测得家蝇3种虫态附着的蜡蚧轮枝菌分生孢子数量差异显著(P<0.05),均表现为成虫>蛹>幼虫。显微观察发现,家蝇成虫周身密集着刚毛、鬃和微毛等体壁外长物,微毛上附着大量的蜡蚧轮枝菌分生孢子,孢子分泌粘液进一步加强附着作用;蛹体大量分布着呈环状的皱褶,在体节接合处有稀疏的棘刺带,蛹体上无分生孢子附着;幼虫体表几乎无皱褶,只在体节接合处附近有带状棘刺,其体表也无孢子附着。【结论】家蝇成虫、幼虫和蛹附着蜡蚧轮枝菌分生孢子的能力与其体表结构有密切关系。Abstract: ObjectiveThe adhesion capacities of Lecanicillium lecanii conidia on adults , larvae and pupae of Mus-ca domestica and the relationship with their surface structures were analyzed to provide references for explaining differ-ent pathogenicities of entomogenous fungi to different development stages of a certain insect. MethodTwo different ino-culation methods (dipping and spraying) were used and the number of conidia adhered to the surface of adults, pupae and larvae was measured by hemocytometer, respectively. Furthermore, the distribution of outgrowths and conidia on the body surface were observed by scanning electron microscope and other microscopies. ResultThe adhesion number of L. lecanii conidia on the surface of three development stages of M. domestica was very different (P<0.05) and the sequence was adults>pupae>larvae. Many outgrowths distributed on all parts of the adult body, such as setae, bristles and microtriches. Many L. lecanii conidia adhered to microtriches and the conidia secreted mucus to further strengthen the adhesion effect. The pupa body was covered with many “band” uneven folds, and there were sparse thorn bands on the junction of somites. There were no L. lecanii conidia adhered to the pupa body. Almost the whole larva body surface had no folds and there were merely thorn bands near the junction of somites. No L. lecanii conidia adhered to the larva body. ConclusionThe body surface structures of adults, pupae and larvae of M. domestica are closely associated with adhesion capacity of L. lecanii conidia.