Zhao Shuang-Shuang, Zhang Ying-Ying, Yan Wei, Cao Ling-Ling, Xiao Yu, Ye Yong-Hao
College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing 210095, P.R. China.
Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, P.R. China.
FEMS Microbiol Lett. 2017 Feb 1;364(3). doi: 10.1093/femsle/fnw287.
Screening for endophytic fungi with antifungal activity is an effective strategy for the discovery of novel biopesticides. Our previous work indicated that Chaetomium globosum CDW7, an endophyte from Ginkgo biloba, exhibited strong inhibitory activity against plant pathogenic fungi in vitro. In this study, we evaluated the CDW7 strain for its antifungal activities against nine phytopathogenic fungi and its biocontrol potential against rape sclerotinia rot caused by Sclerotinia sclerotiorum. The fermentation broth of CDW7 could successfully inhibit disease development in S. sclerotiorum-infected rape in vivo with 57.8% protective efficiency, which is comparable to that of carbendazim (59.8%) at 250 μg mL-1. The fermentation broth also expressed significant activity stability when exposed to 60°C and UV illumination, or when stored at 4°C. Furthermore, we found that 10% fermentation broth can promote the germination and growth of rape seedlings. Followed by the bioassay-guided approach, seven known metabolites were isolated and identified by spectroscopic analyses. Among them, chaetoglobosin A and D exhibited inhibitory activity against S. sclerotiorum with IC50 values of 0.35 and 0.62 μg mL-1, respectively, compared with carbendazim (0.17 μg mL-1). Therefore, our study demonstrated that CDW7 is a promising biocontrol fungus against S. sclerotiorum in agriculture.
筛选具有抗真菌活性的内生真菌是发现新型生物农药的有效策略。我们之前的研究表明，来自银杏的内生真菌球毛壳菌CDW7在体外对植物病原真菌表现出很强的抑制活性。在本研究中，我们评估了CDW7菌株对9种植物病原真菌的抗真菌活性及其对油菜菌核病菌引起的油菜菌核病的生防潜力。CDW7的发酵液能够成功抑制油菜菌核病菌感染的油菜体内病害的发展，保护效率为57.8%，与250 μg mL-1多菌灵的保护效率（59.8%）相当。该发酵液在60°C、紫外线照射或4°C储存时也表现出显著的活性稳定性。此外，我们发现10%的发酵液可以促进油菜幼苗的萌发和生长。随后采用生物活性追踪法，通过光谱分析分离并鉴定了7种已知代谢产物。其中，球毛壳菌素A和D对油菜菌核病菌表现出抑制活性，IC50值分别为0.35和0.62 μg mL-1，而多菌灵的IC50值为0.17 μg mL-1。因此，我们的研究表明CDW7是一种在农业上有潜力防治油菜菌核病菌的生防真菌。
