白僵菌有关培养条件及其与毒力关系的研究

Relationsmp Between Culture Condition and Virulence of Beauveria Bassiana

以麦麸、米糠、黄豆粉、蛋白胨、牛肉膏、蚕蛹粉作供试氮源，在３种动物性氮源的培养基上，白僵菌的产孢量及毒力均高于植物性氖源，其中以蚕蛹粉最优；在１６种不同碳氮比的培养基上，以碳氦比２（４０／２０）和１．５（３０／２０）产孢量和毒力为高；在８种不同ｐＨ值的培养基上，以ｐＨ５．５～６．５最适于产孢，ｐＨ６．３、７．０时，白僵菌的毒力明显较强。研究结果显示，菌落生长量和产孢量往往不一致，而产孢量与毒力则明显相关。

Cultures of a strain of Beauveria bassiana on 6 artificial media containing dif-ferent nitrogen source such as wheat bran,rice bran,bean powerder,peptone,beef extractand silkworm pupa powerder were tested for their growth rates,sporulations,and virulencesto larvae of the Masson's pine caterpillar,Dendrolimus punctatus.The result showed thatthe cultures on media containing nitrogen source from animal sporulated more and werehigher virulent than those on media containing nitrogen source from plant,and silkworm pu-pa powerder proved to be the best nitrogen source.Among 16 artificial media with differentC/N’s,high virulence appeared at C/N=2 and C/N=1.5.From 8 artificial media with dif-ferent pH’s,pH’s 5.5～6. 5 were determined to be suitable for sporulation and pH’s 6.3,7.0 resulted in high virulence.In the present study,sporulation of Beauveria bassiana was notassociated to growth rate,but was correlated to virulence evidently.