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目的:分离和鉴定木香根腐病的病原菌,探讨不同培养基、碳氮源、温度、pH等条件对根腐病病原菌产孢和菌丝生长的影响,以期掌握生物学特性,为该病的田间防治提供理论依据.方法:通过病原菌形态学观察,结合rDNA-ITS测序,在Genbank中经Blast搜索相似性序列,以ITS序列经MEGA 6.O程序构建其分子系统发育树,确定引起木香根腐病的病原菌15b为镰刀菌属真菌Fusarium oxysporum f.sp.ciceris isolate.结果:菌株15b最适菌丝生长的培养基为PDA,生长最适碳、氮源分别为可溶性淀粉和蛋白胨,最适温度为25℃,最适pH值为6;产孢最适碳、氮源分别为可溶性淀粉和蛋白胨,最适温度为30℃,最适pH值为7;光照对菌丝生长发育没有明显影响,但24 h黑暗条件有利于促进孢子产生;菌丝致死温度为61℃、10 min.结论:Fusarium oxysporum f.sp.ciceris isolate是引起木香根腐病的致病菌.“,”Objective:To isolate and identify pathogen of Saussurea lappa root-rot disesse,to study the effects of culture,carbon,nitrogen,temperature,pH on the sporulation and hyphal growth of pathogens,and to research the primary biological features of the fungi to offer a theoretical foundation for the prevention of this disease in the field.Methods:By observing the morphological characters of pathogens and rDNA-ITS sequencing,searching similar sequences by Blast in Genbank,the molecular phylogenetic tree was constructed by MEGA 6.0 program in ITS sequence,and the pathogen 15b was identified as Fusarium oxysporum f.sp.ciceris isolate.Results:Biological characteristics measurement showed that PDA was the optimal medium for mycelium growth,the optimum carbon and nitrogen sources were soluble starch and peptone,the optimal temperature was 25 ℃,the optimal pH value was 6.The optimum carbon and nitrogen sources of sporulation were soluble starch and peptone,the optimal temperature was 30 ℃,and the optimal pH value was 7.The light had no obvious effect to mycelium,while the dark culture conditions in 24 h were suitable for the spore production,and mycelial lethal temperature was 61 ℃ for 10 min.Conclusion:Fusarium oxysporum f.sp.ciceris isolate is reported as the pathogen of root-rot disesse in Saussurea lappa for the first time.