【摘要】 从甜菜夜蛾幼虫体内分离到一种侵染寄主脂肪体、马氏管和中肠的微孢子虫,用电镜技术对该微孢子虫各发育阶段进行研究发现:其分裂体为单核,产孢体,孢子母细胞及孢子均为双核,产孢体分裂产生两个孢子母细胞,具有微粒子属的典型特征。新鲜孢子呈长椭圆形,大小为3.98±0.43×1.65±0.33μm,孢子壁由外壁、内壁及孢子质膜三层组成,孢子器有片层结构的极体、后液泡和极丝,极丝11～13圈,单层螺旋状盘绕于孢子后端,孢原质的外层,该微孢子虫在寄主细胞质中发育而不入侵寄主细胞核,研究还发现:该微孢子虫可以和苜蓿银纹夜蛾核型多角体病毒同时感染甜菜夜蛾。更多还原

【Abstract】 The ultrastructure of the various developmental stages of Nosema sp, a microsporidian pathogen isolated from Laphygma exigua was studied by electron microscopy. The microsporidian primarily infected midgut, fat body, and Malpighian tubes of the host. The life cycle of the pathogen included uninucleate meronts, binucleate sporonts which divided to form two daughter binucleate sporoblasts, binucleate sporoblasts and spores typical of the genus Nosema. The fresh spores were generally long oval or ellipsoidal in shape and measured 3.98±0.43×1.655±0.33μm in size. The polar filement coiled 11～13 circles, arranged in the outer sporoplasm of the posterior portion of the spore at an angle of 55～60° to the axie of spore. The wall of spore was composed of the exospore, endospore and cytoplasmic membrane. The polaroplast consisted of laminal membranes. The posterior vacuole occurred near the posterior pole of the spores. This pathogen developed in the cytoplasm of the host but did not invade the nucleus and could co-infect Laphygma exigua with Autographa californica nuclear polyhedrosis virus (Ac-NPV).更多还原