禾顶囊壳4个变种对禾本科牧草的致病性研究

采用人工接种法测定了禾顶囊壳小麦变种、燕麦变种、玉米变种和禾谷变种对4种禾本科牧草鸭茅、披碱草、苇状羊茅和无芒雀麦的致病性。结果表明,除禾顶囊壳玉米变种Ggm01菌株对披碱草没有致病性外,4个变种对供试的其它牧草都有致病性,且能产生全蚀病的典型症状。其中小麦变种和燕麦变种对供试牧草的致病性强于禾谷变种,玉米变种致病性最弱。各变种的菌株存在着致病性分化。小麦变种Ggt9813菌株对苇状羊茅和披碱草的致病性强于燕麦变种,发病严重度均达到50％以上。目前在我国尚未发现燕麦变种,小麦变种主要出现在北方地区,在牧草上的发生亦不广泛,因此二者具有检疫重要性。

Pathogenicity of Four Varieties of Gaeumannomyces graminis to Gramineal Grasses

Pathogenicity of Gaeumannomyces graminis var.tritici (Ggt),Gaeumannomyces graminis var.avenae (Gga),Gaeumannomyces graminis var.maydis (Ggm) and Gaeumannomyces graminis var.graminis (Ggg) to four species of gramineal grasses,Dactylis glomerata,Elymus dahuricus,Festuca arundinacea and Bromus inermis,were evaluated by seedling inoculation.The results showed that all of the species of tested gramineal grasses were infected by four varieties of Gaeumannomyces graminis and expressed typical symptom of take-all disease,except for Bromus inermis which was inoculated by Ggm01.The pathogenicitys of Ggt and Gga to tested gramineal grasses were higher than that of Ggg,and the pathogenicity of Ggm in four varieties of Gaeumannomyces graminis was the lowest.There were pathogenicity variation in every variety.The pathogenicity of Ggt9813 to Festuca arundinacea and Elymus dahuricus were higher than that of Gga,and the severity of root infection were over 50%.At present,Gga is not found in China and Ggt just prevails in north of China,they did not harm to grasses very widely and so they are of quarantine importance.