河南省小麦茎基腐病调查及优势病原分析

小麦茎基腐病(CR)是近年我国普遍发生的病害之一。为进一步明确河南省小麦CR的发生情况及优势病原种类,2019年对河南省11个小麦主产区的96个生产点进行了调查,并对采自田间典型症状植株上的病害开展了病原菌分离、形态鉴定、rDNA-ITS分子鉴定及致病力分析。结果表明,除驻马店地区轻微发病外,其他10个地区均发病较重,田块发病率平均达78.85%,病情指数、病株率和白穗率分别平均为17.87、48.35% 和3.44%;被调查的小麦品种均不同程度感病,发病较轻的品种占30%、发病较重的占20%、中度感病的占50%;不同地块之间发病程度存在较大差异,土壤肥沃、水分充足、管理精细的地块发病较轻,干旱、盐碱地、肥力不足及管理粗放的地块发病较重;目前,河南省小麦主产区CR主要病原菌为假禾谷镰刀菌(Fusarium pseudograminearum),根据其形态分为6种类型,其中第 Ⅰ 和 Ⅱ 类病原菌分离频率高且分别在8个和6个地区均有分布,致病力分别为42.22和77.78。根据调查结果,建议河南省重视小麦CR防治工作,并加快开展CR致病、小麦抗病机理研究及抗病新品种的选育。

Disease Investigation and Predominant Pathogen Analysis of Wheat Crown Rot in Henan Province

Crown rot (CR) is one of the most common diseases of wheat in China over recent years. To further investigate the incidence and dominant pathogens of wheat CR, diseased samples were investigated and isolated from 96 locations of 11 wheat producing areas in Henan Province in 2019, and the morphological, molecular identification and pathogenicity on wheat were studied. The results showed that CR has been widely distributed in Henan Province, except for the sporadic outbreaks in Zhumadian area. The average incidence of disease for field was 78.85%. Meanwhile, the mean disease index, rate of diseased plant and white head incidence was 17.78, 48.34% and 3.44%, respectively. All of the wheat varieties surveyed were susceptible to the CR disease with different degrees. Among them, mild disease accounted for 30%, severs cases 20% and other 50% were belonged to the moderate disease cases. The Fusarium pseudograminearum was the main pathogen of wheat CR and was divided into 6 categories with strong pathogenicity in Henan Province. Most of the pathogens are belonged to type Ⅰ and type Ⅱ (the pathogenicity index was 42.22 and 77.78, respectively), which were the dominant epidemic isolates in Henan Province. The results have practical significance for accelerating CR precise control, the research on the pathogenesis and disease resistance mechanism of the dominant pathogens and breeding new wheat varieties with disease resistance.