高毒力白僵菌的筛选及对花生甜菜夜蛾的致病力

Screening of Highly Pathogenic Beauveria bassiana Strain and Its Virulence against Peanut Beet Armyworm

为了筛选高毒力的生防白僵菌菌株,本研究对分离获得的4株白僵菌F1、F5、F6、F8的生物学特性进行分析,并在室内检测对甜菜夜蛾的致病力,最后通过大田试验验证了高毒力菌株对花生甜菜夜蛾的防治效果。结果表明,上述4株白僵菌的菌落形态、生长速率、产孢量等生物学性状及致病力存在显著差异。生长最快以及产孢量最高的是菌株F1,菌落呈粉状。菌株F6的分生孢子较其他菌株的分生孢子大。致病力检测结果表明,菌株F1对甜菜夜蛾的致病力最强,LC50和LT50分别是2.9383×106 cfu/m L和5.79 d;其次是菌株F8,菌株F5和F6的毒力相对较弱。大田防效试验表明,菌株F1对花生甜菜夜蛾的防治效果可达75%以上,并在花生叶片具有较强的定殖能力。

To obtain high pathogenic Beauveria bassiana strains, four Beauveria isolates were identified and comparatively analyzed for their bio-characteristics and virulence. Control efficiency of high virulence strains was tested against peanut beet armyworm Spodoptera exigua（Hübner） in the field.The results showed significant differences in the biological characteristics and pathogenicity of the four B. bassiana strains, such as colony morphology, growth rate, and sporulation rate. The strain of the fastest growth and sporulation was F1, while the conidia of F6 strain were larger than those of other strains. F1 strain had the strongest pathogenicity to S. exigua, with LC50 and LT50 of 2.9383×10^6 cfu/m L and 5.79 days, respectively; F8 strain seconded in pathogenicity. The virulences of strain F5 and F6 were relatively weak. In field test, F1 strain showed a control up to 75% against S. exigua, and strong colonization ability on peanut leaves.