甘肃省红豆草病原真菌鉴定及病害发生动态调查
The causal agents of sainfoin fungal diseases and disease dynamics in Gansu Province

为明确甘肃省红豆草的病害种类、发生动态和危害状况,采用病原物分离与培养、形态学及分子生物学鉴定和致病性测定确定红豆草病害种类,于2012-2013年在通渭、渭源、榆中和碌曲4县调查各病害的发病率以确定发生动态,观察病害田间发生特点并结合调查数据评价其重要性。结果表明,4县共发生真菌性病害12种,分别为大茎点霉叶斑病(病原为大茎点霉属真菌Macropho masp.)、壳针孢叶斑病(病原为歪头菜壳针孢Septoria orobina)、炭疽病(病原为白蜡树刺盘孢Colletotrichum spaethianum)、黑秆病(病原为红豆草壳二孢Ascochyta onobrychis、菠菜刺盘孢C. spinaciae和链格孢Alternaria alternata混合侵染)、壳二孢叶斑病、茎点霉叶斑病、尾孢叶斑病、柱格孢白斑病、匍柄霉叶斑病、链格孢黑斑病、锈病和白粉病,其中大茎点霉属真菌、白蜡树刺盘孢和菠菜刺盘孢在红豆草上首次发现;尾孢叶斑病和壳针孢叶斑病为甘肃新记录病害;大茎点霉叶斑病为世界新病害,仅于碌曲县发现。白粉病、锈病、链格孢黑斑病发生于红豆草生长后期,其它病害则始于6月;6-9月危害加重的为黑秆病和柱格孢白斑病,发病率最高达89.7%和96.0%;危害渐轻的为茎点霉叶斑病、壳二孢叶斑病和壳针孢叶斑病,发病率最高达88.7%、57.4%和45.1%。黑秆病和茎点霉叶斑病在甘肃省目前危害最重。
To classify the fungal diseases on sainfoin in Gansu Province, pathogens were isolated and purified for analyses including morphological and molecular identification and pathogenicity test. Disease dynamics was determined by investigation of disease incidence in Tongwei, Weiyuan, Yuzhong, and Luqu counties from June to September in 2012 and 2013. The significance of each disease was evaluated based on disease characteristics occurred in field and data obtained from the investigation. The results showed that there were 12 diseases, including leaf spot caused by Macrophomasp., leaf spot caused bySeptoria orobina, anthracnose caused by Colletotrichum spaethianum, black stem caused by Ascochyta onobrychis, C. spinaciaeand Alternaria alternata, Ascochyta leaf spot, Phoma leaf spot, Cercospora leaf spot, Ramularia white leaf spot, Stemphylium leaf spot, Alternaria black leaf spot, rust and powdery mildew. Three fungi pathogenic to sainfoin, Macrophomasp., C. spaethianum and C. spinaciae were firstly recorded. Macrophoma leaf spot was the new disease in the world. Septoria leaf spot and Cercospora leaf spot were new records in Gansu Province. Powdery mildew, rust and Alternaria black spot occurred at late growing stage, and other diseases occurred from June each year. Generally, disease incidence of black stem and Ramularia white leaf spot increased, and Phoma leaf spot, Ascochyta leaf spot and Septoria leaf spot decreased from June to September, of which the incidences were up to 89.7%, 96.0%, 88.7%, 57.4% and 45.1%, respectively. Black stem and Phoma leaf spot were the most severe diseases in Gansu Province.