几种瓜类作物枯萎病病原菌的分子鉴定及其ITS序列差异性分析.docVIP

几种瓜类作物枯萎病病原菌的分子鉴定及其ITS序列差异性分析 郑雪芳 蓝江林 曹宜 肖荣凤 车建美 刘波* (福建省农业科学院生物技术研究所 福州 350003) 摘 要:比较和分析了福建省几种重要瓜类作物枯萎病病原菌的ITS区序列，结果表明，供试的26个菌株属于两种不同类型的镰刀菌：尖孢镰刀菌和串珠镰刀菌，其中尖孢镰刀菌所占比例较大（54%），为优势种。另外，对尖孢镰刀菌和串珠镰刀菌的ITS区序列进行比对分析，结果显示，这两种类型菌株的差异主要表现在ITS2区间，差异达20.4%，而ITS1区间的序列完全相同或只有1个碱基的差异。对26株供试菌进行亲缘关系分析表明，在同源系数为92%的条件下，26株镰刀菌被划分为2个类群：第1类为尖孢镰刀菌，第2类为串珠镰刀菌。其中，第2类群中的串珠镰刀菌在同源系数为99%的条件下又被细分为2个类群。 关键词： 镰刀菌；分类；鉴定；ITS序列分析 Identification and classification of Fusarium wilt from cucumber, melon，watermelon and bottle gourd in Fujian ZHENG Xue-Fang LIU Bo LAN Jiang-Lin CAO Yi XIAO Rong-Feng CHE Jian-Mei (Biotechnology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China) Abstract:An experiment was conduced to compare and analyze sequece of ITS-rDNA lied in Fusarium wilt from some important cucumis species in Fujiang. Result showed that 26 teste strains were belong to two different types: Fusarium oxysporum and Fusarium moniliforme.The percent of Fusarium oxysporum, which was dominant species, was 54% in the total tested strains.ITS sequence BLAST analysis was applied in Fusarium oxysporum and Fusarium moniliforme, result showed that main differece of two type Fusarium strains lied in ITS2, the differenc of them was significant at 20.4% level, however, ITS1 sequences of them were absolutely identical or one base differece.The phylogenetic tree of 26 tested strains indicated that 26 tested strains was divided into two major groups while the homology confficient was 92%.The first group was Fusarium oxysporum and the second group was Fusarium moniliforme, which was subdivided into two groups while the homology confficient was 99%. Key word:Fusarium; classification; identification; IIS sequence analysis 瓜类作物枯萎病是由致病性镰刀菌引起的，是瓜类作物生产中重大病害之一。传统对病原真菌的分类、鉴定主要基于形态特征、生理生化指标、致病性测定等，但大部份真菌种类多、分布广、形态特征复杂, 不能对未知菌株进行准确鉴定，而且少数形态特征和生理生化指标随着环境的变化而不稳定()。因此,传统的菌株分类鉴定方法引起分类系统的不稳定或意见分歧。随着分子生物技术的发展，RAPD、SSR、AFLP、ITS等分子标记技术被广泛应用于病原真菌的的鉴定(Nicholson et a1．，1993),分类(Alalounakis，1999 ；Crowhurstrn e