对西花蓟马高效的球孢白僵菌菌株筛选及产孢特性研究

Selection of Beauveria bassiana Strains against Frankliniella occidentalis and Their Conidial Production Characteristics

西花蓟马Frankliniella occidentalis是我国新近发现的一种危害极大的外来入侵害虫,为寻求一条可持续、无污染的新型防治方法,本文从33株球孢白僵菌Beauveria bassiana中筛选出4株对西花蓟马成虫高毒力的菌株——球孢白僵菌N-5、SZ-26、SZ-22和SZ-15。并分别从耐热性和产孢特性两个方面进行筛选。结果表明:在30℃下,白僵菌菌株SZ-26对西花蓟马成虫的致死中时LT50最短,为3.094 d,10 d的校正死亡率最高,为98.3%;在34℃下,菌株SZ-26使西花蓟马致死速度最快(LT50为3.429 d),导致试虫在第10 d的校正死亡率最高,为94.32%;菌株SZ-26的产粉量(16.93 mg.g 1)和有效产孢数(2.703×1015孢子.g 1)均显著高于其他3个菌株。本研究显示出球孢白僵菌菌株SZ-26在西花蓟马的防治上具有极大的开发潜力。

Western flower thrips （WFT）, Frankliniella occidentalis （Pergande） （Thysanoptera： Thripidae）, is a devastating invasive insect pest discovered in China recently. To explore alternative strategy for sustainable control of the pest population, the pathogenicity of 33 isolates of the entomopathogenic fungus Beauveria bassiana to adult WFT was tested under laboratory condition. Based on the isolates tested, four strains （N-5, SZ-26, SZ-22, SZ-15） were selected for their high virulence and mortality rates within 10 days. The isolates were screened for their virulence against WFT adults at higher temperatures and for their conidial production characteristics. The results showed that the strain SZ-26 outperforms in temperature tolerance with the shortest LTs0 of 3.094 d and highest mortality rates of 98.3% within 10 days at 30 ℃. Similarly, the strain SZ-26 showed the shortest LTs0 of 3.429 d to control WFT adults and highest mortality rates of 94.32% within 10 days at 34℃. The yields ofconidia powder and efficient conidia number of strain SZ-26 is significantly more than other selected isolates. The results indicate that the strain SZ-26 has great potential to control F. occidentalis in field in an integrated management program as a biological control agent.