胡萝卜根腐病拮抗菌活性及杀菌剂的室内毒力评价

Antagonistic bacteria activity against carrot root rot and indoor toxicity evaluation of fungicides

【目的】筛选对胡萝卜根腐病病原菌具有拮抗活性的菌株,评价19种杀菌剂对胡萝卜根腐病的室内毒力。【方法】通过皿内拮抗法结合活体活性测定拮抗菌株对胡萝卜根腐病病原菌的抑制效果,利用菌丝生长速率法测定19种杀菌剂对胡萝卜根腐病病原菌的室内毒力抑制效果。【结果】萎缩芽孢杆菌(Bacillus atrophaeus DM3-18)对胡萝卜根腐病病原菌的活体抑制率达72.17%。19种杀菌剂中,多菌灵对胡萝卜根腐病病原菌的抑制活性最好,EC_(50)值为0.0028 mg/L;咪鲜胺、戊唑醇、甲基硫菌灵、十三吗啉、苯醚·丙环唑、肟菌·戊唑醇、苯甲·嘧菌酯对病原菌也有较好的抑制效果,EC_(50)值均小于20 mg/L;甲霜·恶霉灵对胡萝卜根腐病抑制效果最差,EC_(50)值为8407.9368 mg/L。【结论】萎缩芽孢杆菌为胡萝卜根腐病生物防治的有效拮抗菌株,具有进一步开发和应用的潜力;多菌灵对胡萝卜根腐病病原菌的抑制效果较强,可用于该病害的防治。

【Objective】Screen the strains having antagonistic activity against carrot root rot pathogen and assess the indoor toxicity of 19 fungicides to carrot root rot.【Methods】The inhibition effect of the antagonistic strain on the pathogen of carrot root rot was determined by in vitro and in vivo antagonism method.The mycelium growth rate method was used to assess the indoor toxicity inhibitory effects of 19 fungicides on the pathogen.【Results】Bacillus atrophaeus DM3-18 had in vivo inhibitory rate of 72.17%on the carrot root rot pathogen.Out of the 19 fungicides,carbendazim had the best inhibitory activity against carrot root rot pathogen,with an EC_(50) value of 0.0028 mg/L;prochloraz,tebuconazole,thiophanate methyl,tridemorph,difenoconazole·propiconazole,trifloxystrobin·tebuconazole,and difenoconazole·azoxystrobin also had good inhibitory effects,with EC_(50) value less than 20 mg/L;with an EC_(50) value of 8407.9368 mg/L,metalaxyl-hymexazol had the worst inhibitory effect.【Conclusion】Bacillus atrophicus is an antagonistic strain for biological control of carrot root rot that has the potential for further development and application.Carbendazim has inhibitory impact on the carrot root rot pathogen and can be used to control the disease.