昆虫学报 ›› 2020, Vol. 63 ›› Issue (6): 751-758.doi: 10.16380/j.kcxb.2020.06.011

• 研究论文 • 上一篇    下一篇

对桃蚜高毒力的蜡蚧菌菌株筛选

刘明科1,#, 闫芳芳2,#, 齐禹哲1, 黄岩1, 闫雪梨1, 钱逸彬1, 李茂业1,*   

  1. (1. 安徽农业大学植物保护学院, 植物病虫害生物学与绿色防控安徽普通高校重点实验室, 合肥 230036; 2. 四川省烟草公司攀枝花市公司, 四川攀枝花 617026)
  • 出版日期:2020-06-20 发布日期:2020-07-02

Screening of Lecanicillium strains with high virulence to Myzus persicae (Hemiptera: Aphididae)

LIU Ming-Ke1,#, YAN Fang-Fang2,#, QI Yu-Zhe1, HUANG Yan1, YAN Xue-Li1, QIAN Yi-Bin1, LI Mao-Ye1,*   

  1.  (1. Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; 2. Sichuan Panzhihua Branch Tobacco Company, Panzhihua, Sichuan 617026, China)
  • Online:2020-06-20 Published:2020-07-02

摘要:  【目的】桃蚜Myzus persicae是一种世界性的重要农作物害虫,近年来已对多种化学杀虫剂产生抗性。本研究旨在筛选对桃蚜具有高毒力且培养性状优良的蜡蚧菌菌株。【方法】选用蜡蚧菌属Lecanicillium2个种的7个菌株,即刀孢蜡蚧菌L. psalliotae 3个菌株(HFLP006, HFLP021和HFLP025)和渐狭蜡蚧菌L. attenuatum 4个菌株(HFLA032, HFLA041, HFLA064和HFLA066),接种在SDAY平板上培养并观察菌落生长与产孢性状;以2.0×107孢子/mL悬浮液用浸渍法测定对桃蚜无翅成蚜的致死率和致死中时(LT50);进而用系列浓度(1.0×104-1.0×108孢子/mL) HFLP006和HFLA032菌株孢子悬浮液测定其对桃蚜无翅成蚜的致死中浓度(LC50);利用体视显微镜逐日观察1.0×108孢子/mL HFLP006菌株孢子悬浮液侵染后无翅成蚜的染病症状变化。【结果】在SDAY平板上7个蜡蚧菌菌株的菌落形态基本相似,其中HFLP006和HFLA032菌株的生长与产孢性状较好,接种后15 d的菌落直径分别为50.75 mm和51.13 mm,产孢量分别为13.90×107和11.50×107孢子/cm2;各菌株的孢子萌发率均超过了96.00%,其中HFLP006菌株的萌发率达到99.28%。对桃蚜无翅成蚜致病力最高的是HFLP006菌株,处理后7 d引起的累计校正死亡率为83.56%,显著高于其他菌株,LT50为3.74 d,小于其他菌株;其次为HFLA032,处理后7 d引起的桃蚜无翅成蚜累计校正死亡率为6301%,LT50为5.75 d。毒力测定发现,处理后7 d菌株HFLP006和HFLA032对桃蚜无翅成蚜的LC50值分别为0.21×106和1.86×106孢子/mL。在接种1.0×108孢子/mL HFLP006菌株孢子悬浮液后,第2天桃蚜成蚜活力减弱,虫体腹部开始出现褐斑,之后胸腹部逐渐变褐,足和触角变白,全身干瘪,体表长出大量白色丝状菌丝。【结论】HFLP006菌株对桃蚜无翅成蚜的致死率远高于其他菌株且致死时间最短,因此具有应用于桃蚜生物防治的潜力。此外,HFLP006菌株在SDAY培养基上表现出良好的培养性状。研究结果为该菌株的进一步规模化发酵提供了理论依据。

关键词: 桃蚜, 蜡蚧菌, 刀孢蜡蚧菌, 渐狭蜡蚧菌, 菌落形态, 致病性, 生物防治

Abstract: 【Aim】 The green peach aphid, Myzus persicae, is an important crop pest distributed worldwide. This pest has developed resistance to a variety of chemical pesticides in recent years. The purpose of this study is to screen Lecanicillium strains with high virulence against M. persicae and excellent performance in cultivation. 【Methods】 Seven strains of two Lecanicillium species, namely three strains of L. psalliotae (HFLP006, HFLP021 and HFLP025) and four strains of L. attenuatum (HFLA032, HFLA041, HFLA064 and HFLA066), were selected, and the colony growth and spore production of these strains cultivated on SDAY plates were observed. The lethality and the medium lethal time (LT50) of these strains against the apterous adults of M. persicae were measured by immersion method using a 2.0×107 conidia/mL spore suspension, and the medium lethal concentration (LC50) values of HFLP006 and HFLA032 strains were determined with a graded series of concentrations of spore suspension (1.0×104-1.0×108 conidia/mL). The symptoms of apterous adults infected by HFLP006 strain at the concentration of 1.0×108 conidia/mL spore suspension were observed under stereoscopic microscope. 【Results】 The colony morphology of the seven strains of Lecanicillium on the SDAY plate was basically similar. The HFLP006 and HFLA032 strains showed better growth and spore-producing traits, with the colony diameter of 50.75 and 51.13 mm, and the spore yields of 13.90×107 and 11.50×107 conidia/cm2, respectively, at 15 d after inoculation. The spore germination rates of all the strains were above 96.00%, with the HFLP006 strain showing the germination rate of 99.28%. The HFLP006 strain also displayed the highest pathogenicity against the apterous adults of M. persicae, causing an 83.56% corrected accumulative mortality at 7 d after treatment, which was significantly higher than those caused by the other fungal strains. Moreover, the LT50 value of the HFLP006 strain against the apterous adults of M. persicae was 3.74 d, which was significantly lower than those of the other strains. The HFLA032 strain also had good performance against the apterous adults of M. persicae, causing a corrected accumulative mortality of 63.01% and a LT50 of 5.75 d against the apterous adults of M. persicae. Furthermore, virulence determination revealed that the LC50 values of HFLP006 and HFLA032 strains against the apterous adults of M. persicae at 7 d after treatment were 0.21×106 and 1.86×106 conidia/mL, respectively. The HFLP006 strain at a concentration of 1.0×108 conidia/mL spore suspension impaired the vitality of M. persicae adults on the 2nd day after treatment, and brown spots were observed on the abdomen of aphid body. Then the thorax and abdomen became brown, the legs and antennae became white, and the whole body became very wizened. Finally, a large amount of white filamentous hyphae grew out from aphid body. 【Conclusion】 The HFLP006 strain is a candidate biological control agent against M. persicae since it causes the highest mortality and the shortest lethal time against the apterous adults of M. persicae. In addition, the HFLP006 strain shows an excellent cultivation performance on SDAY medium. The results of this study provide a theoretical basis for further largescale fermentation of this fungal strain.

Key words: Myzus persicaeLecanicilliumLecanicillium psalliotaeLecanicillium attenuatum, colony morphology, pathogenicity, biological control