长江流域禾谷镰孢菌群部分菌株系统发育学、产毒素化学型及致病力研究

从采集自长江流域引起小麦赤霉病的禾谷镰孢菌群(Fusarium graminearum clade)菌株中选取了31株,扩增并测定了这些菌株的EF-1α(translation elongation factor)、PHO(phosphate permease)基因序列,利用相关软件进行了系统发育分析。对这些菌株的产毒素化学型进行了分子检测。同时,用两个小麦品种(扬麦158和安农8455)测定了菌株的致病力。系统发育分析表明绝大多数菌株与F.asiaticum聚为一枝,只有一个菌株11027与F.graminearum聚类。30株F.asiaticum中有24株产脱氧雪腐镰孢菌烯醇(deoxynivalenol,DON)和3-乙酰脱氧雪腐镰孢菌烯醇(3-acetyldeoxynivalenol,3-AcDON),另外6株产雪腐镰孢菌烯醇(Nivalenol,NIV)。一株F.graminearum菌株11027产脱氧雪腐镰孢菌烯醇(DON)和15-乙酰脱氧雪腐镰孢菌烯醇(15-acetyldeoxynivalenol,15-AcDON)。在扬麦158上,菌株间的致病力分化较为明显,产NIV毒素的菌株致病力普遍较弱,强致病力的菌株都产3-AcDON毒素。结果表明在我国长江流域,产3-AcDON毒素的F.asiaticum是引起小麦赤霉病的优势种群,中抗赤霉病的小麦品种扬麦158可以有效评价菌株的致病力强弱。

Phylogenetic analysis, chemotype diversity, and pathogenicity of the Fusarium graminearum clade in the Yangtze basin

EF-1α (translation elongation factor) gene and PHO (phosphate permease) gene of 31 Fusarium graminearum clade strains collected from the Yangtze basin were amplified and sequentced,and the phylogenetic analyses were made.The trichothecene mycotoxin chemotypes of these strains were assayed by PCR,and relative pathogenicity was determined on wheat cultivars Yangmai 158 and Annong 8455.Phylogenetic analysis based on sequences of EF-1α and PHO gene showed that most of strains were clustered with a distinct clade.i.e.Fusarium asiaticum,and only one strain 11027 clustered with F.graminearum.Twenty four of the 30 F.asiaticum strains were DON (deoxynivalenol) and 3-AcDON (3-Acetyldeoxynivalenol) type,and the other 6 strains were NIV (nivalenol) type,while the one F. graminearum strain 11027 was DON (deoxynivalenol) and 15-AcDON (15-Acetyldeoxynivalenol) type.On wheat cultivar Yangmai 158,there was differentiation in virulence between strains.Almost all of the high virulent strains werc 3-AcDON producer,while virulence of NIV producers was generally weber.In the Yangtze basin of China,population of F.asiaticum with a 3-AcDON chemotype is predominant.The wheat cultivar Yangmai 158 is a valuable material to assay the pathogenicity of the strains of F.graminearum clade.