白僵菌对二化螟致病力及与Bt混用协同作用研究

Study on pathogenicity of Beauveria bassiana to Chilo suppressalis and synergism with Bacillus thuringiensis

文章研究3株来源不同的白僵菌株对二化螟幼虫致病性及与苏云金芽孢杆菌混用对致病力协同作用,结果表明,3株白僵菌株对二化螟幼虫均表现出致病性,但致病力存在较大差异,球孢白僵菌Bb-YM致病力显著高于球孢白僵菌Bb170428和布氏白僵菌NEAU30305,对2、3龄幼虫致病力更高,显著高于对其他虫龄幼虫致病力。菌株Bb-YM以LC_(50)和LC_(80)浓度处理越冬幼虫校正死亡率分别为80.90%和92.09%,成虫羽化率仅为13.04%和2.90%。菌株Bb-YM与菌株Bt64混用对二化螟幼虫致病力具有协同增加作用,并显著缩短幼虫致死中时间,与菌株Bt64 LC_(50)和LC_(70)混用增效比达2.1373和3.9663。研究结果对开展白僵菌绿色防控二化螟和菌株高效使用具有重要意义和应用价值。

The pathogenicity of three Beauveria strains from different sources to Chilo suppressalis larvae and the synergism with Bacillus thuringiensis were studied in this paper.The results showed that the three Beauveria strains showed obvious infectivity to the C.suppressalis larvae,but their toxicity to the larvae was significantly different.The pathogenicity of B.bassiana Bb-YM was significantly higher than that of B.bassiana Bb170428 and B.brongniartii NEAU30305,and it had the highest pathogenicity to the 2nd and 3rd instar larvae,significantly higher than that to other instar larvae.When strain Bb-YM treated the overwintering larvae with LC_(50)and LC_(80)concentrations,the corrected mortality of the larvae was 80.90% and 92.09%,and the adult emergence rate was 13.04% and 2.90%,respectively.The mixed use of strain Bb-YM and strain Bt64 had a significant synergistic effect on the pathogenicity of C.suppressalis larvae,and significantly shorten the median lethal time of larvae.The mixed use with strain Bt64 LC_(50)and LC_(70)had a synergism ratio of 2.1373 and 3.9663.The research results had important significance and practical application values for the development of green control of C.suppressalis with B.bassiana and high efficiency use of the strain.