昆虫学报 ›› 2020, Vol. 63 ›› Issue (1): 22-28.doi: 10.16380/j.kcxb.2020.01.003

• 研究论文 • 上一篇    下一篇

一株侵染豌豆蚜的昆虫病原真菌的分离及鉴定

张挺峰1,2, 王睿1, 刘长仲1,*   

  1. (1. 甘肃农业大学植物保护学院, 甘肃省农作物病虫害生物防治工程实验室, 兰州 730070; 2. 河西学院农业与生物技术学院, 甘肃张掖 734000)
  • 出版日期:2020-01-20 发布日期:2020-01-19

Isolation and identification of an entomopathogenic fungus infecting Acyrthosiphon pisum (Hemiptera: Aphididae)

ZHANG Ting-Feng1,2, WANG Rui1, LIU Chang-Zhong1,*    

  1. (1. Engineering Laboratory of Crop Diseases and Pests of Gansu Province, College of Plant Protection, Gansu Agricultural University, Lanzhou 730070, China; 2. College of Agriculture and Biotechnology, Hexi University, Zhangye, Gansu 734000, China)
  • Online:2020-01-20 Published:2020-01-19

摘要: 【目的】从采集到的自然染菌的豌豆蚜Acyrthosiphon pisum虫尸分离纯化得到一株病原真菌,定名为TF-2。本研究旨在确定该菌株的分类地位,为豌豆蚜生物防治提供真菌资源。【方法】对自然染菌的豌豆蚜虫尸上寄生真菌TF-2进行回接试验,分离纯化出致病菌株TF-2;在显微镜下配制TF-2菌株不同浓度孢子悬浮液,采用浸渍法和离体叶片饲养法测定其对豌豆蚜成虫的毒力;利用光学显微镜观察菌株形态学特征。PCR扩增TF-2的rDNA-ITS序列并测序,构建系统发育树对TF-2 菌株进行分子鉴定。【结果】毒力测定结果表明,TF-2菌株对豌豆蚜成虫表现出很强的致病力,1×107孢子/mL处理6 d后豌豆蚜成虫校正死亡率达到100%。TF-2在PDA培养基上菌落呈圆形,白色或淡黄色毡状,菌落背面呈奶油色;菌株孢梗呈瓶状,在菌丝上单生或侧生2~3个,大小为(19-42) μm×(1.1-2.5) μm,基部较粗至尖端逐渐变细,分生孢子长椭圆形,大小为(4.2-11.8) μm×(1.6-2.6) μm。菌丝体产生晶体呈八面体。该菌株的rDNA-ITS序列与长孢蜡蚧菌Lecanicillium longisporum (GenBank登录号: KX426564)的rDNA-ITS核苷酸序列一致性达99%,位于系统发育树的同一分支。【结论】菌株TF-2被鉴定为豌豆蚜的病原真菌长孢蜡蚧菌L. longisporum,对豌豆蚜的生物防治具有潜在的应用价值。

关键词: 豌豆蚜, 长孢蜡蚧菌, 昆虫病原真菌, ITS序列, 毒力

Abstract: 【Aim】 One pathogenic fungus named TF-2 was isolated and purified from naturally entomopathogen-infected Acyrthosiphon pisum. This study aims to determine the classification status of the strain and to provide fungal resources for biological control of A. pisum. 【Methods】 The pathogenetic strain TF-2 was isolated and purified by back infestation test. Spore suspensions of TF-2 strain at different concentrations were prepared under microscope, and its virulence to adult pea aphid was measured by dipping method and in vitro leaf feeding method. The morphological characteristics of TF-2 strain were observed by optical microscope. The rDNA-ITS sequence of TF-2 strain was amplified by PCR and sequenced, and the phylogenetic tree was constructed for molecular identification of TF-2 strain. 【Results】 The results of virulence test showed that TF-2 strain showed strong pathogenicity to A. pisum adults, causing 100% corrected mortality at 6 d after treatment at a concentration of 1×107 conidia/mL spore suspension. The colony of TF-2 is round on PDA medium, white or light yellow felt-like, and the bottom of the colony is creamy. The results of optical microscope observation showed that the spore phialides of the strain are bottle-shaped, and there are 2-3 spore phialides singly or laterally grown on the hypha, (19-42) μm×(1.1-2.5) μm in size. The base is relatively thick and gradually taper to the tip, and the conidia are oval, (4.2-11.8) μm×(1.6-2.6) μm in size. Mycelium produces crystals as octahedra. The rDNA-ITS sequence of the strain TF-2 has 99% nucleotide identity with that of Lecanicillium longisporum (GenBank accession no.: KX426564) and shares the same branch of phylogenetic tree. 【Conclusion】 The strain TF-2 is determined as the pathogenic fungus L. longisporum with potential application value in biological control of A. pisum.

Key words: Acyrthosiphon pisum, Lecanicillium longisporum, entomopathogenic fungi, ITS sequence, virulence