利用Tri8基因区分中国小麦赤霉病菌的毒素化学型

Identification of three chemotypes of Fusarium graminearum species complex in China by Tri8 gene

由镰孢菌(Fusarium spp.)引起的小麦赤霉病在全世界均有发生,我国小麦赤霉病主要由禾谷镰孢菌复合种(Fusarium graminearum species complex,FGSC)所引起,根据产生单族毒素种类分为三种化学型,分别为3-乙酰脱氧雪腐镰孢菌烯醇(3-AcDON)、15-乙酰脱氧雪腐镰孢菌烯醇(15-AcDON)和雪腐镰孢菌烯醇(NIV)化学型。为了更方便地对禾谷镰孢菌复合种进行化学型的区分,本研究利用三对引物分别扩增了三种化学型菌株的Tri8基因并进行了序列测定,根据不同化学型菌株的基因序列差异,进行了特异性引物设计和筛选。利用设计的引物同时扩增三种化学型的Tri8基因并用AvaI内切酶进行酶切,根据酶切片段的大小区分三种化学型。研究表明该方法可准确有效地区分我国小麦赤霉病菌的化学型。

Fusarium head blight caused by Fusarium spp. occurs worldwide on small grain cereals. In China,Fusarium head blight is mainly caused by Fusarium graminearum species complex（ FGSC）. FGSC produces trichothecene toxins and it was divided into 3 chemotypes： nivalenol（ NIV）,15-acetyldeoxynivalenol（ 15-AcDON）and 3-acetyldeoxynivalenol（ 3-AcDON）. In order to distinguish these three chemotypes,Tri8 gene of three chemotype isolates was amplified by using three pairs of primers and sequenced. According to the difference of Tri8 gene sequences of three chemotypes,specific primers were designed and screened. We found that 3 chemotypes can be differentiated according to the size of fragments after Tri8 gene was digested with AvaI enzyme.The procedure developed in this study could be used to identify the chemotype of the major pathogen of Fusarium head blight in China.