脐腹小蠹高致病力虫生真菌菌株的筛选
Screening of highly virulent strains of fungi entomopathogenic to Scolytus schevyrewi Semenov
范丽华1** 牛辉林2 张金桐1*** 刘金龙1 杨美红1 宗世祥3
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DOI：
作者单位：1. 山西农业大学文理学院化学生态研究所 太谷 030801；2. 宁夏哈巴湖国家级自然保护区管理局高沙窝管理站 盐池 751501；3. 北京林业大学省部建森林培育与保护教育部重点实验室 北京 100083
中文关键词：脐腹小蠹，致病力，培养特征，几丁质酶，蛋白质酶，FDA水解酶，筛选
英文关键词：Scolytus schevyrewi, pathogenicity, culture characteristics, chitinase, proteinase, FDA hydrolase activities, screening
中文摘要：
【目的】 脐腹小蠹Scolytus schevyrewi Semenov是白榆的钻蛀性害虫之一，为找到对脐腹小蠹的高致病力虫生真菌菌株。【方法】 通过室内喷雾法研究了5株虫生真菌菌株对脐腹小蠹幼虫的致病力，结合各菌株菌落直径、孢子萌发率、产孢量和菌落生长速率4个培养特征，筛选到Bb773和Pc546 2株优良的菌株，在此基础上，进一步对这2株菌株的几丁质酶、蛋白质酶和荧光素二乙酸酯（FDA）水解酶活性进行了测定。【结果】 菌株Bb773和菌株Pc546在浓度为1×107 孢子/mL悬浮液处理后，10 d的后脐腹小蠹幼 虫的校正死亡率分别达96.67%和90.00％，致死中时分别为3.61 d和4.18 d。菌株Bb773的几丁质酶、FDA水解酶和蛋白质酶活性在接种后第2～10天均高于菌株Pc546，2株菌株蛋白质酶活性差异均达到了显著水平（P<0.05）。【结论】 确定了菌株Bb773在脐腹小蠹害虫生物防治中具有潜在的应用价值。
英文摘要： [Objectives] To identify highly virulent strains of fungi entomopathogenic to Scolytus schevyrewi Semenov, one of the boring pests of Ulmus pumila. [Methods] The pathogenicity of two superior strains, Bb773 and Pc546, to S. schevyrewi larvae was examined and the culture characteristics of these strains, including the final colony size, spore generation, sporulation and average growth rate, determined. A preliminary screening examined chitinase, proteinase and FDA hydrolase activities of the two selected strains. [Results] Adjusted death rates and median lethal time (LT50) of S. schevyrewi larvae ten days after infection with strains Bb773 and Pc546 at a concentration of 1×107 conidia/mL were 96.67%, 90.00％ and 3.61 d , 4.18 d, respectively. Chitinase, proteinase and FDA hydrolase activity of strain Bb773 was higher than that of strain Pc546 after about 2-10 days culture and proteinase activity was also significantly higher (P<0.05). [Conclusion] Strain Bb773 has greater potential as a biological control agent for the sustainable control of S. schevyrewi．