海南一品红细菌性叶斑病病原菌的分离与鉴定研究

 为明确海南省近几年发生的一品红细菌性叶部病害的病原菌特别是该病原菌的分子特征,为该病害的治理提供可行的依据,本文描述了2005年海南省部分花圃一品红植株上发生的细菌性叶斑病症状,并通过致病性测定、BIOLOG分析和16SrDNA序列比较将分离的病原菌鉴定为黄单胞菌属(Xanthomonas);部分碳源利用测定进一步显示2005年海南分离的菌株与2004年海南报道的细菌性疫病病原菌存在差异,但与杭州地区报道的一品红细菌性叶斑病菌基本一致。利用黄单胞菌模式种典型菌株的核糖体DNA内转录间隔区(internal transcribed spacer,ITS)序列构建系统发育树,结果显示3个海南菌株与巴豆黄单胞菌(Xanthomonas codiaei)和地毯草黄单胞菌(X.axonopodis)单独聚合成群,其中与巴豆黄单胞菌亲缘关系最近。

Isolation and identification of the pathogen of poinsettia leaf spot in Hainan

A causal agent of poinsettia bacterial leaf spot was isolated and identified for effective management in Hainan province in 2005. The symptoms of the disease were described and the pathogenicity test, Biolog test and analysis of 16S rRNA gene sequence and 16S-23S rDNA internal transcribed spacer (ITS) were undertaken to elucidate the precise position of the causal bacterium. The results indicated that the causal agent belonged to the genus Xanthomonas and was consistent with the strains from Zhejiang province, but different with that from Hainan province in 2004 on utilization of partial carbon sources. The 3 strains from Hainan in 2005 were most closely related to Xanthornonas codiaei in the phylogenetic tree, which were constructed based on ITS sequences of all known Xanthornonas type strains. In addition, the 3 Hainan strains and X. codiaei as well as Xanthornonas axonopodis were within one group and well separated from other species of Xanthomonas.