马尾松毛虫高毒力球孢白僵菌菌株的生物学特性

Biological characteristics of highly virulent strains of Beauveria bassiana for Dendrolimus punctatus

【目的】研究马尾松毛虫高毒力球孢白僵菌菌株的生物学特性,为利用球孢白僵菌对马尾松毛虫进行生物防治及大规模生产球孢白僵菌提供理论依据。【方法】在PDA培养基上测定6个温度梯度(17、20、23、26、29和32℃)对供试球孢白僵菌高毒力菌株(B-2、B-14和B-19)生长速率、产孢量及孢子萌发率的影响;以查比克培养基为基础,分别以等质量的3种不同碳源或氮源代替蔗糖和硝酸钾,测定不同碳、氮源对供试球孢白僵菌高毒力菌株生长速率、产孢量及孢子萌发率的影响。【结果】供试菌株在不同温度条件下的生长存在一定差异,过高或过低均不利于B-2、B-14和B-19菌株菌丝生长、产孢及孢子萌发,在26℃下各项生物学指标均达最高值,菌株的生长速率、产孢量和孢子萌发率分别为3.36~3.77 mm/d、9.33×10~4~16.33×10~4个/mL和92.67%~99.67%;在不同碳氮源利用方面,最适生长、产孢的碳源为葡萄糖,菌丝生长速率和产孢量分别为3.56~4.35 mm/d、1.00×10~4~1.33×10~4个/mL,但孢子萌发率普遍不高;最适生长的氮源为蛋白胨,菌丝生长速率为4.40~4.81 mm/d;最适产孢及孢子萌发的氮源为酵母浸出液,产孢量和孢子萌发率分别为5.67×10~4~51.33×10~4个/mL、58.03%~100.00%。【结论】B-2菌株可优先选作球孢白僵菌工业化生产菌种;在26℃下选择葡萄糖和酵母浸出液为碳氮源可提高菌剂的生产效率。

[Objective]Biological characteristics of highly virulent strains of Beauveria bassiana were tested to provide theoretical basis for production and biocontrol of B. bassiana against Dendrolimus punctatus. [Method]Effects of six different temperatures（17, 20, 23, 26, 29 and 32 ℃） on growth rate, sporulation quantity and spore germination rate of highly virulent strains of B. bassiana（B-2, B-14 and B-19） were measured respectively on PDA media. With Czapek media as the base, sucrose and potassium nitrate were replaced by three kinds of carbon sources or nitrogen sources of the same mass, in order to study the effects of different carbon sources and nitrogen sources on growth rate, sporulation quantity and spore ger-mination rate of highly virulent strains of B. Bassiana. [Result]The three tested strains grew differently under different tem-peratures. Extremely high and low temperatures were not beneficial to mycelial growth, sporulation and spore germination of B. bassiana strains. All biological indicators could reach the highest level under 26 ℃. The growth rate, sporulation quantity and spore germination rate were 3.36-3.77 mm/d, 9.33×10^4-16.33×10^4/mL and 92.67%-99.67% respectively. In terms of car-bon sources application, glucose was the most suitable for growth and sporulation, with growth rate of 3.56-4.35 mm/d and sporulation quantity of 1.00-1.33 ×10^4/ml, but spore germination rate was low. Peptone was the best nitrogen source for mycelial growth（4.40-4.81 mm/d） and yeast extract was the most suitable for sporulation（sporulation quantity 5.67×10^4-51.33×10^4/mL） and spore germination（spore germination rate 58.03%-100.00%）. [Conclusion]Strain B-2 can be preferen-tially selected for industrial production of B. bassiana. At temperature 26 ℃ , carbon source glucose and nitrogen source yeast extract can increase production effeciency of B. bassiana.