摘要
为明确从田间采集草地贪夜蛾Spodoptera frugiperda幼虫体内发现的一种微孢子虫的分类地位和致病性,利用传统形态学观察和分子生物学技术对该微孢子虫进行鉴定,同时采用室内生物活性测定法对其致病性进行分析。结果显示,该微孢子虫的形态学特征与家蚕微孢子虫Nosema bombycis相近,具有典型微孢子虫超微组成结构,孢子壁厚度为195.00~205.15 nm,极丝盘旋于孢子后极内侧10~12圈;其基因组的基因间隔区(intergenic spacer,ITS)和小亚基核糖体RNA(small subunit ribosomal RNA,SSU)序列与已报道的家蚕微孢子虫相关序列的相似度分别达94.34%和99.50%,系统发育树显示该微孢子虫属于微孢子虫属Nosema,与家蚕微孢子虫亲缘关系最近。该微孢子虫侵染草地贪夜蛾1龄和2龄幼虫5 d时的LC_(50)分别为2.51×10^(7)孢子/mL和2.48×10^(7)孢子/mL;侵染3龄幼虫10 d时的LC_(50)为3.79×10^(7)孢子/mL;侵染4龄幼虫15 d时的LC_(50)为3.98×10^(7)孢子/mL;且当微孢子虫浓度为1.0×108孢子/mL时,草地贪夜蛾1至4龄幼虫的LT_(50)分别为3.04、3.86、7.47和10.43 d。表明该微孢子虫隶属微孢子虫属,对草地贪夜蛾不同龄期幼虫均有较强的致病力,具有良好的开发应用潜力。
In order to clarify the classification status and pathogenicity of a microsporidia found in fall armyworm Spodoptera frugiperda larvae collected from corn fields, the microsporidium was identified by traditional morphology and modern molecular techniques, and the pathogenicity of the microsporidia was determined by bioassay. The results showed that the morphological characteristics of the microsporidia were similar to those of Nosema bombycis, with a typical ultrastructure of microsporidia. The thickness of its spore wall ranged from 195.00 nm to 205.15 nm, and the polar filaments circled 10-12 turns inside the posterior pole of the spore. The intergenic spacer(ITS) and small subunit ribosomal RNA(SSU) sequences shared 94.34% and 99.50% similarity to the reported corresponding sequence of N. bombycis. Phylogenetic analysis showed that the microsporidia belonged to the genus Nosema,which was closely related to N. bombycis. The LC_(50)values of the 1st and 2nd instar larvae of S. frugiperda infected by the microsporidia were 2.51×10^(7) spores/mL and 2.48×10^(7) spores/mL at day 5, respectively. The LC_(50)value of the 3rd instar larvae was 3.79×10^(7) spores/mL at day 10 after infection, and the LC_(50)value of the 4th instar larvae was 3.98×10^(7) spores/mL at day 15 after infection. When the concentration of this microsporidia was 1.0×10~8 spores/mL, the LTvalue of the 1st to 4th instar larvae of S. frugiperda was 3.04, 3.86, 7.47 and 10.43 days, respectively. The results indicated that the microsporidia belonged to the genus Nosema, and had a strong virulence against different instars of S. frugiperda, which has good potential for development and application for S. frugiperda control.
作者
张海剑
孙雪莲
郝浩阳
刘树森
郭宁
石洁
Zhang Haijian;Sun Xuelian;Hao Haoyang;Liu Shusen;Guo Ning;Shi Jie(Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China,Ministry of Agriculture and Rural Affairs,Integrated Pest Management Center of Hebei Province,Institute of Plant Protection,Hebei Academy of Agricultural and Forestry Sciences,Baoding 071000,Hebei Province,China;College of Plant Protection,Hebei Agricultural University,Baoding 071000,Hebei Province,China)
出处
《植物保护学报》
CAS
CSCD
北大核心
2022年第5期1513-1520,共8页
Journal of Plant Protection
基金
河北省重点研发计划(20326501D)
河北省农林科学院基金项目(2021120204)
国家现代农业产业技术体系(CARS-02)。
关键词
草地贪夜蛾
形态学特征
ITS
SSU
微孢子虫
致病力
生物防治
Spodoptera frugiperda
morphological characteristics
ITS
SSU
microsporidia
pathogenicity
biological control
