中文摘要：

由禾谷镰孢菌群Fusariumgraminearumclade引起的赤霉病是小麦的重要病害。为明确山东省小麦赤霉病菌的种群组成及其致病力，于2011年和2012年从山东省15地市分离了95株小麦赤霉病菌，在形态和分子生物学鉴定种的基础上，采用鉴定B型毒素化学型的特异性引物进行毒素化学型分析。在95个菌株中，93株分离物为禾谷镰孢菌F.graminearum，2株为燕麦镰孢茵F．avenaceum。94株分离物为脱氧雪腐镰孢茵烯醇（deoxynivalenol，DON）化学型，1株为雪腐镰孢菌烯醇（nivalenol，NIV）化学型。在94株DON毒素化学型菌株中，90株为15-乙酰脱氧雪腐镰孢茵烯醇（15-acetyldeoxynivalen01，15-AcDON）化学型，4株为3-乙酰脱氧雪腐镰孢茵烯醇（3-acetyldeoxynivalenol，3-AcDON）化学型。在小麦扬花期，采用单花滴注接种法对29个菌株进行了致病力测定，供试菌株的致病力分化明显。表明在山东省冬小麦产区，产15-AcDON毒素的F．gra-minearum是小麦赤霉病菌的优势种群。

英文摘要：

Fusarium head blight （FHB） or scab caused by Fusarium graminearum clade is one of the most serious diseases of wheat in China. A total of 95 isolates with symptoms of FHB were collected from 15 cities in Shandong Province during 2011 -2012. After the morphological and molecular identification of Fusarium species, a PCR assay was explored to determine the trichothecene mycotoxin chemotypes of Fusarium species. The results showed that 93 strains belonged to F. graminearum, and the other 2 strains were F. avenaceum. Chemotype detection results showed ninety-four strains had deoxynivalenol （DON） chemotypes, while the rest one isolate had nivalenol （NIV） chemotype. Among the 94 DON strains, 90 were 15-acetyldeoxynivalenol （15-AcDON） and 4 were 3-acetyldeoxynivalenol （3-AcDON）. Pathogenic- ity differentiation of 29 strains was obvious at wheat anthesis in the field experiments. F. graminearum with a 15-AcDON chemotype was predominant species in Shandong Province.