甘肃省燕麦主产区白粉病调查及病原鉴定

为了解甘肃省燕麦（Avena sativa）产区白粉病的发生及其危害情况，本研究对张掖、甘南、武威和定西等市（州）主要燕麦产区进行了白粉病调查，同时采集病样对白粉病病原进行鉴定。结果表明，除甘南州的合作市和碌曲县未发现白粉病外，其余调查县（市）均有发生，其中天祝县种植的‘甜燕麦’病情指数最高可达50.10，山丹县种植的‘牧乐思’和‘加燕2号’病情指数较低，分别为0.28和0.34；同一燕麦品种在不同调查区发病程度差异较大，其中‘甜燕麦’病情指数变化最大（3.40~50.10），‘白燕7号’在永登县病情指数高达43.29，在通渭县仅为1.22；不同品种在同一种植区的发病程度也有差异。结合形态学和分子生物学方法对调查过程中采集的白粉病病原菌进行鉴定，发现甘肃省燕麦白粉病可能存在禾本科布氏白粉菌黑麦专化型Blumeria.graminis（DC.）f.sp.secalis和禾本科布氏白粉菌燕麦专化型B.graminis（DC.）f.sp.avenae共2种。

Incidence of Oat Powdery Mildew and Pathogen Identification in the Main Oat Production Areas of Gansu Province

Oat powdery mildew is a popular wider,onset heavier oat diseases all over the world. To pinpoint the occurrence situation and damage in the main production area of oat (Avena sativa) in Gansu province of northern China. The occurrence of oat powdery mildew in each leaf was investigated,and leaves were collected from the field for pathogen identification. The investigation was located in Tongwei County of Dingxi City,Shandan and Minle Counties of Zhangye City,Tianzhu County of Wuwei City,and Gannan County of Hezuo City. The results showed that the powdery mildew occurred in most survey counties except for Hezuo and Luqu. ‘Sweet oat’ had the highest disease index (50.10) in Tianzhu County and the disease index of ‘Mulesi’ and ‘Jiayan No.2’ in Shandan County was lower (0.28 and 0.34,respectively). The incidence of the same oat varieties was significantly different in different survey areas. The disease index of ‘Sweet oat’ in Tianzhu County is 3.40~50.10;that of ‘Baiyan 7’ in Yongdeng County was 43.29,and only 1.22 in Tongwei County. The differences of disease severity among different oat varieties in the same area were observed. Combined with morphological and molecular biological methods,the partial sequence of oat powdery mildew pathogens collected during the investigation was analyzed and two different powdery mildew specific types were identified,the one was Blumeria. graminis (DC.) f.sp. secalis,the other was B. graminis (DC.) f.sp. avenae.