小麦茎基腐病病原假禾谷镰刀菌与赤霉病之间的关系

近年来，黄淮地区小麦茎基腐病发生严重，假禾谷镰刀菌是黄淮地区小麦茎基腐病的优势病原菌，同时也可引起小麦赤霉病。为明确假禾谷镰刀菌与小麦赤霉病的关系，本研究从山东省商河县小麦茎基腐病重病田块分别采集苗期和成熟期小麦病株，通过分离鉴定发现，苗期小麦茎基腐病的优势病原菌为假禾谷镰刀菌，且致病性试验结果显示，假禾谷镰刀菌在人工接种条件下能够引起严重的小麦赤霉病；此外，在小麦苗期田间的玉米秸秆上能够观察到尚未成熟的子囊壳，对子囊壳进行真菌分离鉴定，发现其包含禾谷镰刀菌和假禾谷镰刀菌形成的子囊壳。在小麦成熟期，从小麦赤霉病病穗中也分离到了假禾谷镰刀菌。这是山东省首次报道假禾谷镰刀菌引起的小麦赤霉病。综上，在小麦茎基部和穗部均能分离到假禾谷镰刀菌，且假禾谷镰刀菌在人工接种条件下能够引起严重的小麦赤霉病。结合当前黄淮地区小麦茎基腐病严重发生以及普遍秸秆还田的现状，推测假禾谷镰刀菌可能会助推小麦赤霉病的发生流行。

Relationship between Fusarium pseudograminearum Causal Agent of Fusarium Crown Rot and Wheat Scab

Fusarium crown rot(FCR) has occurred seriously in Huanghuai region of China in recent years. Fusarium pseudograminearum,the dominant pathogen of FCR in Huanghuai region,can also lead to Fusarium head blight(FHB). In order to clarify the relationship between F.pseudograminearum and occurrence of FHB,we collected wheat samples with typical symptoms of FCR at seedling and maturity stages from serious FCR field in Shanghe Country,Shandong Province. The results showed that F.pseudograminearum was the dominant pathogen of FCR at seedling stage of wheat by isolation and identification,and pathogenicity test showed F.pseudograminearum also caused serious FHB under the conditions of artificial inoculation. In addition,immature perithecia were observed on maize straws,and the fungi isolated from perithecia was identified as F.graminearum and F.pseudograminearum. F.pseudograminearum was also isolated from wheat head with typical FHB symptoms at maturity stage of wheat. This is the first report of FHB caused by F.pseudograminearum in Shandong Province. In conclusion,F.pseudograminearum was isolated from wheat stem base and wheat head,and it also caused serious FHB syptoms under the conditions of artificial inoculation. Considering the serious occurrence of FCR and the tranditional straw returning to field in Huanghuai region,we could speculate that F.pseudograminearum may contribute to the occurrence and epidemic of FHB.