甘薯长喙壳菌是习居土壤且寄主广泛的危险病原体，所致病害在我国甘薯产区及东南、西南省区部分作物上均有分布。该菌是庞大复合种，种水平具有严格寄主专化性及遗传变异。本研究拟在预研基础上，以采集自然和耕作生境的土壤为样本，建立土壤中甘薯长喙壳菌快速灵敏分离方法，探明该菌为我国土壤中土著种群及其形态学、生物学和产生挥发性有机化合物等特征；采用交互可孕性检验、系统发育分析和微卫星标记等方法解析其群体遗传多样性，明确各菌群的遗传背景和亲缘关系；研究该菌对我国的寄主和非寄主植物的致病性，比较分析毒蛋白Cerato-platanin（CP）和致病关键基因cp的表达量与菌株致病的关系，阐明我国土壤生境菌株和寄主上分离菌株在遗传背景和致病性等方面的差异。预期结果将为解析和评估我国甘薯黑斑病等可能来自甘薯长喙壳菌土著菌群、自然土壤生境中甘薯长喙壳菌对农林作物的潜在致病性风险及制定病害综合防控策略提供科学依据。

Ceratocystis fimbriata is a soil-borne fungus with a wide geographical distribution, which is a serious pathogen in Southeast and Southwest of China. C. fimbriata is a species of complex, due to its strict host specialization and genetic variability. The aim of this study is to establish a fast and sensitive isolation method from natural and cultivated soil, to detect this fungus being native to China or introduced, to demonstrate the genetic background and relationship with the methods of interfertility tests, phylogenetic analyses and microsatellite diversity, to compare the difference of pathogenicity based on the production of toxic protein of Cerato-platanin (CP) and the expression of cp gene. This study will provide a scientific evidence for the evaluation of the potential risk of C. fimbriata from natural soil to the crops and forests, and for plant diseases prevention and control. It is also verification for the hypothesis that the pathogens causing sweet potato black rot and pomegranate wilt diseases may be members native to China.