花椰菜苗期立枯病病原鉴定及室内药剂筛选

Pathogen identification on cauliflower seedling blight and its fungicide screening in laboratory

【目的】明确引起花椰菜苗期枯萎病的病原菌,并筛选出有效低毒的生物农药.【方法】进行了病原菌的分离、鉴定、生物学特性测定及室内药剂筛选.【结果】表明该病害为丝核菌属的立枯丝核菌(Rhizoctonia solani)引起的苗期立枯病;立枯丝核菌生长的最适温度为30℃;光照条件为L/D=16h/8h;室内药剂筛选发现50%乙蒜素水剂、63%恶霉蛋白水剂和特效灭萎灵粉剂对立枯丝核菌的抑制效果较好,抑菌率分别达到了100%、88.44%和75.98%;其EC_(50)值分别为233.87,0.965 9,1 348.96μg/mL.【结论】63%恶霉蛋白水剂是防治花椰菜苗期立枯病的有效低毒的生物农药.

【Objective】In order to identify the pathogen caused of broccoli seedling blight,and to screen effective and low toxicity of biological pesticide.【Method】The pathogen was isolated and identified from the root of the cauliflower seedling stage,and the biological characteristics of the pathogen were determined.The fungicide was screened against the pathogen【Result】The pathogen caused of broccoli seedling blight was identified as Rhizoctonia solani.The optimum growth temperature for the fungal was30℃,and the illumination condition(L/D)was16h/8h.Three fungicides,ethylicin(AS),fumaricin(DP)and texiaomiejunling(DP),showed better inhibition against R.solani,and the inhibitory rates reached100%,88.44%and75.98%,respectively.EC50values were233.87μg/mL,0.9659μg/mL and1348.96μg/mL,respectively.【Conclusion】Fumaricin(DP)was the optimum candidate fungicide to control cauliflower seedling blight.