多黏类芽胞杆菌Paenibacillus polymyxa菌株P1防治黄瓜霜霉病的研究

Control effect of Paenibacillus polymyxa strain P1 against cucumber downy mildew

通过离体叶片筛选法,得到1株对黄瓜霜霉病原菌有较强抑制作用的多黏类芽胞杆菌Paenibacillus polymyxa菌株P1。通过液体发酵和剂型处理,将P1制成含量2×10^(9) cfu/mL的悬浮剂分别进行室内和大田药效测试。室内药效试验结果表明,P1-SC悬浮剂对黄瓜霜霉病的防治效果与用药浓度呈正相关。当使用浓度为1.25×10^(7) cfu/mL时,P1悬浮剂对霜霉病的防治效果与化学农药250 g/L嘧菌酯SC的相似;当使用浓度为5.0×10^(7) cfu/mL时,防治效果显著大于嘧菌酯(P≤0.05)。2017年和2018年连续两年大田药效测试结果显示,经P1-SC处理(3000 mL/hm^(2))的黄瓜植株霜霉病病情指数(2.53,2.48)显著低于经250 g/L嘧菌酯SC(600 mL/hm^(2))处理的植株(4.33、6.22),防治效果(86.16%,89.90%)显著高于后者(76.34%、74.95%)(P≤0.05)。

By in vitro detached leaf assay,a strain P1 of Paenibacillus polymyxa was obtained,with strong antagonistic ability against the pathogen of cucumber downy mildew.Through the processes of liquid fermentation and formulation,P1 was prepared into a suspension concentrate(SC)containing 2×10^(9) cfu/mL,which was used for indoor and field efficacy tests.Indoor test showed that it was positively correlated with the application concentration of P1-SC on the efficacy of controlling cucumber downy mildew.When the application concentration was at 1.25×10^(7) cfu/mL,the control efficacy was equal to that of azoxystrobin 250 g/L SC.When the concentration was at 5.0×10^(7) cfu/mL,the efficacy was significantly greater than(P≤0.05)that of azoxystrobin 250 g/L SC.Field tests in 2017 and 2018 showed that when treated with P1-SC(3000 mL/hm^(2)),the disease index(2.53,2.48)was significantly lower than that of azoxystrobin 250 g/L SC(600 mL/hm^(2)),while the control efficacy(86.16%,89.90%)was significantly higher.