[背景]根腐病在青稞生产中的危害日趋严重,阻碍了青稞根腐病的有效防控及青海省青稞产业的发展.然而人们对青稞根腐病的研究甚少且病原菌不详.[目的]明确青稞根腐病发生的危害、病原及致病性,为青稞根腐病的防控提供理论依据.[方法]采用常规的组织分离法分离青稞根腐病病原,通过形态鉴定与分子鉴定结合的方法对病原进行鉴定,并采用烧杯水琼脂法测定其致病性.[结果]共分离得到4株青稞根腐病病原菌,鉴定为Clonostachys rosea,有较强的致病性且致病性差异显著,经柯赫氏法则验证为青稞根腐病病原菌,并且是一种新的青稞根腐病病原,该类根腐病也是一种新的根腐类病害,在国内外属首次发现.[结论]Clonostachys rosea可引起青稞根腐病且致病性强.“,”[Background]The increasingly serious root rot has posed a threat to the production of naked barley (Hordeum vulgare L.var.nudum Hook.f.) and hampered the prevention and control of the disease and the development of the naked barley industry in Qinghai province.However,the root rot of naked barley has been rarely studied and the pathogens are unclear.[Objective]This paper aims to clarify incidence and pathogens of the root rot in naked barley and the pathogencity of the pathogens,which is expected to lay a theoretical basis for the prevention and control of the disease.[Methods]The conventional method of tissue isolation was adopted to isolate pathogens of root rot in naked barley.The pathogens were detected by both morphological identification and molecular identification,and their pathogenicity was determined with a beaker of water-agar.[Results]A total of 4 stains with strong and significantly different pathogenicity were isolated,which were identified as Clonostachys rosea.As verified by Koch\'s postulates,they were new pathogens of root rot of naked barley,and the induced root rot was found for the first time at home and abroad.[Conclusion]C.rosea can cause root rot in naked barley with strong pathogenicity.