从野外昆虫体内分离的5株微孢子虫的生物学特性与分子系统发育研究  

Biological Characters and Molecular Phylogenesis of Five Microsporidian Isolates from Field Insects

作　　者：黄旭华 祁广军 汤庆坤 潘志新 朱方容 黄元姣[2] 林强 罗梅兰 石美宁 吴勇浒[2] 黄深惠 

机构地区：[1]广西壮族自治区蚕业技术推广总站,南宁530007 [2]广西医科大学,南宁530021

出　　处：《蚕业科学》2012年第5期864-872,共9页ACTA SERICOLOGICA SINICA

基　　金：广西科学研究与技术开发项目(No.桂科攻0718004-2A);广西自然科学基金项目(No.桂科自1013072;桂科自0832179);"八桂学者"工程专项

摘　　要：从广西蚕区的野外昆虫菜粉蝶(Pieris rapae)、桑尺蠖(Hemerophila atrilineata)、斜纹夜蛾(Spodoptera litura)的体内收集到5株对家蚕有一定食下感染力的微孢子虫,通过生物学性状、分子系统发育研究,为其分类鉴定提供依据。来自野外昆虫的5株微孢子虫均具有Nosema属的生物学特性:显微镜下观察形状均呈长卵圆形,与家蚕微孢子虫(Nosema bombycis,Nb)有较明显差异;在生活史的各发育阶段均为双核,以二分裂方式增殖,最后形成双核成熟孢子;与Nb抗血清均产生阳性凝聚反应;超微结构观察均具双核,极丝圈数在12～14圈之间,极丝倾斜角与Nb有差异。根据5株野外昆虫微孢子虫与其它昆虫微孢子虫基于SSU rRNA基因序列构建的系统发育树,以及基于SSU rRNA和rRNA ITS基因序列进行的相似性和遗传距离分析,初步认为5株野外昆虫微孢子虫与家蚕微孢子虫同属异种。In this study, 5 microsporidian isolates with certain peroral infectivity to Bombyx moriwere collected from three field insect species namely Pieris rapae, Hemerophila atrilineata and Spodoptera litura, in Guangxi sericultural areas. Studies on biological characters and molecular phylogenesis were carried out to provide guidance for their taxonomy. It was found that all 5 microsporidian isolates from field insects had the biological characters of genus Nosema. Their spores were all in long oval shape under microscope, which were obviously different from that of Nosema bombycis （Nb）. Their nuclei were present in pair at all developmental phases of life cycle, propagated in binary fission, and thendeveloped into two mature spores. Positive coagulation reaction was observed between all 5 microsporidian iso- lates and Nb antiserum. Ultrastructural observation show- ed that all 5 microsporidian cells were binuclear and had 12- 14 polar filament coils. Tilt angles of polar filament were different with Nb. Phylogenetic tree based on SSU rRNA sequences and analyses on similarity and genetic distance between SSU rRNA and rRNA ITS sequences of 5 microsporidian isolates and other insect microsporidianspecies indicated that these 5 microsporidian isolates and Nb belong to different species of the same genus.

关 键 词：野外昆虫 微孢子虫 生物学特性 分子系统发育 

分 类 号：S884.21[农业科学—特种经济动物饲养] Q959.115.92[农业科学—畜牧兽医]