大麦种质资源成株期对西藏白粉菌自然群体的抗性评价及8个菌株的毒性谱分析

Evaluation of Adult-plant Resistance of Barley Accessions to the Natural Inocula of Blumeria graminis f.sp.hordei in Tibet and Assessment of the Virulence Spectra of Eight Strains of It

大麦白粉病病原菌禾谷布氏白粉菌(Blumeria graminis f.sp.hordei)毒性变异频率高,常因主要流行小种的更替而导致抗病基因“丧失”功能。该病在我国东部以及西南部大麦栽培区域为害日益严重,急需发掘抗病基因资源,为抗白粉病育种提供抗源材料。本研究对来源于云南和西藏的不同地点的8个菌株进行毒性谱分析,选用其中强毒性菌株16248-4苗期人工接种鉴定300份大麦品种资源的抗病性,同时将这些大麦资源在白粉病常发流行区西藏林芝种植,利用病原菌自然群体田间鉴定成株期抗病性。毒性谱分析发现,云南菌株对鉴别品系的平均毒性频率高于西藏林芝地区菌株。在所鉴定的大麦资源中,全生育期高抗材料92份,具有成株抗性特点的品种97份,另外还发现12份材料在苗期表现为抗病,但在成株期表现为感病。本研究获得的大麦抗白粉病品种资源可为大麦抗白粉病育种提供良好的抗源材料。

Powdery mildew,caused by Blumeria graminis f.sp.hordei,is an important air-born leaf disease on barley.The pathogen's virulence changes frequently.The virulence variations of the predominant pathogen races can cause resistance genes to powdery mildew in barley to lose their function;consequently,some main barley cultivars have become susceptible to this disease,which is getting more severe in barley-growing areas in eastern and south-western China.Therefore,it is urgent to characterize more resistance genes to powdery mildew,which are fundamental material sources for barley resistance breeding programs.In this study,we assessed the virulence spectra of eight strains of B.graminis f.sp.hordei derived from different locations in Yunnan Province and Linzhi,Tibet,of which the most virulent strain 16248-4 was used to evaluate powdery mildew resistance in 300 barley accessions at the seedling stage.The adult-plant resistance of these accessions was assessed in the nursery plots in the constant epidemic areas of powdery mildew in Linzhi,Tibet using the local natural air-born inocula of B.graminis f.sp.hordei.The virulence spectra of the eight strains of B.graminis f.sp.hordei were assessed on a set of differential barley lines;as a result,the strains from Yunan had a higher average virulence frequency than those from Linzhi,Tibet.Among all the tested barley accessions,92 were all-stage resistant to powdery mildew,97 had adult-plant resistance,and 12 had seedling resistance but no adult-plant resistance.The resistant barley accessions to powdery mildew selected in this study will be highly valuable resistant sources for barley breeding.