布氏白僵菌侵染杨干象幼虫体壁的扫描电镜及透射电镜观察  

SEM and TEM observations of Beauveria brongniartii( Sacc. ) Petch infecting body wall of Cryptorhynchus lapathi L.( Coleoptera:Curculionidae) larvae

作　　者：曹庆杰[1] 迟德富[1] 宇佳[1] 冉亚丽 

机构地区：[1] 东北林业大学林学院 [2] 辽宁省北票市森林病虫害防治检疫站

出　　处：《北京林业大学学报》2015年第5期96-101,共6页Journal of Beijing Forestry University

基　　金：“十二五”国家科技支撑计划项目(2012BAD19B07-04)

摘　　要：为了解布氏白僵菌对杨干象幼虫的侵染过程,利用扫描电镜与透射电镜研究了布氏白僵菌对杨干象幼虫体壁的侵染过程及超微结构变化。扫描电镜结果显示:接种12 h后,分生孢子成功附着于杨干象幼虫体壁不同区域,如气孔、感器周围与节间膜部位;接种24 h后,最早观察到布氏白僵菌以芽管或菌丝的形式穿透杨干象幼虫体壁,无附着孢产生;接种90、96 h后,由虫体内穿出的菌丝在虫体表面开始大量繁殖。透射电镜结果显示:菌丝在穿透过程中伴随着机械压力与组织溶解现象。接种第24 h时,菌丝穿入表皮;到第36 h时,大量菌丝侵入到皮细胞层中;到第48 h时,菌丝侵入皮细胞层后使皮细胞层发生变形,菌丝周围出现电子密度很低的光晕;到第60 h,表皮层与皮细胞层分离,菌丝周围的细胞器溶解,细胞核遭到破坏,菌丝周围出现絮状溶解物,这种现象在国内外均未见报道,证实了菌丝侵入杨干象幼虫体内过程中有酶的参与。到第72 h时,细胞内排列松弛变成空泡;第84 h时,菌丝段以无隔、1个隔或2个隔的方式在血腔内大量繁殖;到第96 h,菌丝从表皮中穿出。In order to understand the infection process of Beauveria brongniartii（ Sacc.） Petch to Cryptorhynchus lapathi L. larvae,we observed the ultrastructural changes of body wall of C. lapathi larvae infected by B. brongniartii using scanning electronic microscopy（ SEM） and transmission electron microscopy（ TEM）. SEM observation indicated that,12 hours after inoculation,spores adhered onto different areas of body wall of the C. lapathi larvae such as spiracles,sensilla surroundings and internode membranes.Twenty-four hours after inoculation, hypha or germ tubes of B. brongniartii penetrated into the integuments of C. lapathi larvae,and no appressoria was found. After inoculation for 90 and 96 hours,hypha penetrated out from the surface of C. lapathi and began to multiply rapidly. TEM observation showed that the penetration of hypha was the combination of mechanical pressure and histolysis. After inoculation for 24 hours,hypha penetrated into cuticula,and 36 hours after inoculation,a lot of hypha penetrated into the epidermis. After inoculation for 48 hours,epidermis deformed after the hypha penetrated into it and halos with low electron density could be observed at the front end of penetrated hypha. After inoculation for 60 hours,cuticula was separated from epidermis,a lot of hypha penetrated into the epidermis,organelles near hypha were dissolved,cell nucleuses were destroyed,and flocculent solutes appeared around the hypha. Those phenomena,reported for the first time in our study,confirm that enzymatic action was involved in the process of B. brongniartii intruding into C. lapathi larvae. After inoculation for 72 hours,the cell structure was loosened and became abundant vacuolus. After inoculation for 84 hours,hypha massively self-reproduced by non-septa or one-septa or two-septa ways in blood cavity. After inoculation for 96 hours,hypha penetrated out from cuticula.

关 键 词：球孢白僵菌 杨干象 侵染过程 扫描电镜 透射电镜 

分 类 号：S763.38[农业科学—森林保护学]