球孢白僵菌胞外蛋白酶与其毒力的关系

Relation between Extracellular Protease of Beauveria Bassiana and Its Virulence to Dendrolimus Punctatus

用液体培养和明胶琼脂平板法研究了球孢白僵菌不同菌株以及不同世代的胞外蛋白酶产酶水平与其毒力的关系。试验结果表明，不同菌株间以及同一菌株的不同世代间产酶水平存在着明显的差异，而且产酶水平的高低与其对马尾松毛虫的毒力存在着明显的线性相关性。因此可以认为白僵菌的胞外蛋白酶活力是构成毒力的主要因素之一。明胶琼脂平板法是测定白僵菌胞外蛋白酶产酶水平的一种简便而有效的方法。

The relation between extracellular protease from 28 Beauveria bassianastrains and subcultures of a strain and their virulence were studied by liquid culture andgelatin-agar plate methods.The result showed that there was obvious difference in produc-tion of extracellar protease among the strains and subcultures,and the protease activity levelwas obviously correlated with the virulence of B.bassiana to Dendrolimus punctatus,indicat-ing that extracellular protease activity can be regarded as an estimate of the virulence of B.bassiana.