球孢白僵菌和爪哇虫草菌对烟草青枯病的防治效果

Control effect of tobacco bacterial wilt by Beauveria bassiana and Cordyceps javanica

摘要:

【背景】烟草青枯病是青枯劳尔氏菌(Ralstonia solanacearum，简称青枯菌)引起的土传病害，给烟草生产带来了极大的损失。【目的】探究实验室2株生防菌株球孢白僵菌(Beauveria bassiana) HZXJ和爪哇虫草菌(Cordyceps javanica) Bd01对青枯菌的抑制作用及防效。【方法】采用平板对峙、琼脂扩散法及生长曲线法测定2株生防菌株及其发酵液对青枯菌生长的抑制作用；通过室内盆栽试验及大田试验测定菌株HZXJ与Bd01 1×10⁸孢子/mL悬浮液对烟草青枯病的防治效果。【结果】平板对峙试验发现，菌株HZXJ与Bd01发酵液在10 d时对青枯菌的抑制率分别为51.28%和47.59%。菌株HZXJ与Bd01的灭菌发酵上清液对青枯菌10 d时的平板抑制率分别为62.54%和35.49%。根据生防菌与病原菌OD₆₀₀绘制的生长曲线也表明菌株HZXJ与Bd01的无菌发酵上清液对青枯菌均有抑制作用。盆栽试验结果表明，菌株HZXJ与Bd01 1×10⁸孢子/mL悬浮液处理后15 d对烟草青枯病防效分别为43.33%和19.99%，52%氯尿硫酸铜可溶性粉剂800倍液的防效为39.99%；菌株HZXJ与Bd01处理后30 d对烟草青枯病的防效分别为43.75%和21.87%，52%氯尿硫酸铜可溶性粉剂800倍液的防效为46.90%。大田试验结果表明，菌株HZXJ与Bd01 1×10⁸孢子/mL悬浮液处理后15 d对烟草青枯病的防效分别为80.00%和35.00%，52%氯尿硫酸铜可溶性粉剂800倍液的防效为40.00%；菌株HZXJ与Bd01处理后30 d对烟草青枯病的防效分别为52.63%和63.16%，52%氯尿硫酸铜可溶性粉剂800倍液的防效为53.98%。【结论】菌株HZXJ和Bd01对青枯菌有显著抑制效果。结合盆栽试验和大田试验可以证明菌株HZXJ和Bd01有作为烟草青枯病生防菌的潜力。

关键词:烟草青枯病;青枯劳尔氏菌;球孢白僵菌;爪哇虫草菌;生物防效

Abstract:

[Background] Tobacco bacterial wilt is a soil-borne disease caused by Ralstonia solanacearum, causing huge losses to tobacco production. [Objective] To investigate the inhibitory effect and control efficiency of two biocontrol strains of Beauveria bassiana HZXJ and Cordyceps javanica Bd01 on R.solanacearum. [Methods] The inhibitory effects of the two biocontrol strains and their fermentation broths on the growth of R.solanacearum were measured by plate confrontation test, agar diffusion method, and growth curve method. The effect of strain HZXJ and Bd01 1×10⁸ conidia/mL suspension on tobacco bacterial wilt was determined by indoor pot experiment and field experiment. [Results] The plate confrontation test showed that the inhibition rates of strain HZXJ and strain Bd01 on the fermentation broth at 10 days were 51.28% and 47.59%, respectively. The inhibition rates of the pasteurized fermentation broths of B.bassiana HZXJ and C.javanica Bd01 on R.solanacearum cultured at 10 days were 62.54% and 35.49%, respectively. The growth curves drawn by biocontrol bacteria and R.solanacearum OD₆₀₀ also showed that the aseptic fermentation supernatants of HZXJ and Bd01 both had inhibitory effects on R. solanacearum. The results the control efficiency of strain HZXJ and strain Bd01 on tobacco bacterial wilt after treatment with 1×10⁸ conidia/mL suspension for 15 days was 43.33% and 19.99%, respectively, and the control efficiency of 52% copper chloride sulfate soluble powder 800 times solution was 39.99%. The control effect of HZXJ and Bd01 on tobacco bacterial wilt at 30 days was 43.75% and 21.87% respectively, and the control effect of 52% copper chloride sulfate soluble powder 800 times solution was 46.90%. The results of field test showed that the control efficiency of strain HZXJ and Bd01 1×10⁸ conidia/mL suspension for 15 days was 80.00% and 35.00%, respectively, and the control efficiency of 52% copper chloride sulfate soluble powder 800 times solution was 40.00%. The control effect of strain HZXJ and Bd01 on tobacco bacterial wilt at 30 days was 52.63% and 63.16%, respectively, and the control effect of 52% copper chloride sulfate soluble powder 800 times solution was 53.98%. [Conclusion] B.bassiana HZXJ and C.javanica Bd01 showed significant inhibitory effects on R.solanacearum. Both strains had the potential of serving the biocontrol of tobacco bacterial wilt.

Key words:tobacco bacterial wilt;Ralstonia solanacearum;Beauveria bassiana;Cordyceps javanica;biocontrol effect