山西省植物病原镰孢菌种群分布及遗传变异分析  

Analysis of Population Distribution and Genetic Variation of Plant Pathogenic Fusarium in Shanxi Province

作　　者：王琳[1] 李新凤[1] 徐玉梅[1] 畅引东[1] 王建明[1] 

机构地区：[1]山西农业大学农学院,山西太谷030801

出　　处：《中国农业科学》2017年第10期1802-1816,共15页Scientia Agricultura Sinica

基　　金：山西省科技攻关项目(20120311019-3);山西省科技基础条件平台建设项目(1105-0104)

摘　　要：【目的】通过对镰孢菌(Fusarium)ITS、EF-1α和β-tubulin 3个基因序列比较分析,筛选适合于镰孢菌种类鉴定的基因序列,并以此序列分析山西省植物病原镰孢菌种群分布及遗传变异情况。【方法】从2013—2015年在山西省11市28县(区)采集分离的625株镰孢菌菌株中选取形态学清晰的菌株进行ITS、EF-1α和β-tubulin基因序列联合分析,运用Sequencher软件对序列进行拼接和校对,将测序结果与NCBI及FUSARIUM-ID数据库中所有已公布的序列进行BLAST分析,结合下载概念清晰或标准种序列,运用Clustal X和Gel Doc软件进行序列对齐和编辑,运用MEGA、Excel、DNAstar和Taxon Gap软件分析镰孢菌种内种间遗传变异情况,从ITS、EF-1α和β-tubulin中筛选适合镰孢菌种类鉴定的基因序列,并以此序列分析山西省镰孢菌的种群分布特点等。【结果】在3个候选基因序列中,EF-1α基因序列是最适用于镰孢菌种类鉴定的基因序列,其种间平均遗传距离分别是种内平均遗传距离的24倍,种内差异小于种间差异的种的数量最多,达到供试种的73%,物种鉴定准确率最强,达到87%。基于EF-1α基因片段的系统发育分析结果表明,在供试的27种镰孢菌中,有22种表现出单系性,相同种的不同菌株以较高支持率聚成独立支。在27种镰孢菌中,F.oxysporum是山西省镰孢菌的优势种,分离频率最高(22.1%),且分布最广,在23个县(区)均有分布;其次是F.solani(13.8%),在14个县(区)有分布。从不同地区镰孢菌的种群结构及分布来看,运城、临汾、忻州、长治、吕梁、晋中和太原均以F.oxysporum为优势种,朔州以F.lateritium为优势种,大同以F.solani为优势种,晋城以F.verticillioides为优势种,阳泉以F.incarnatum为优势种;其中晋中和忻州的镰孢菌种类最丰富,临汾次之,朔州最少。从不同寄主镰孢菌的种群结构及分布来看,番茄上镰孢菌的种类最多(15种),其次是马铃薯(13种)和大豆(1[Objective] The objectives of this study are to obtain the sequences of ITS, EF-la and β-tubulin gene regions from plant pathogen, Fusarium spp., compare the suitable gene sequences for species identification, and to analyze the population distribution and genetic variation of Fusarium spp. in Shanxi Province by using the suitable gene sequences. [ Method] A total of 625 Fusarium strains were collected from 28 counties and 11 cities in Shanxi Province from 2013 to 2015. The ITS, EF-la and β-tubulin gene fragments of the morphology of clear strains from 625 strains were sequenced and analyzed. The sequences were assembled and edited using Sequencher software, then blasted in GenBank in NCBI and FUSARIUM-ID databases. The sequences from the clearly documented and reference species were downloaded. All the sequences were aligned and edited manually using ClustalX and GelDoc. The inter- and intra-specific variations of Fusarium spp. were analyzed with MEGA, Excel, DNAstar and TaxonGap. All the three gene sequences consisting of ITS, EF-la and β-tubulin were selected for the taxonomy of the Fusarium species and then the best optimal fragment genes were used in the analysis of the population distributions ofFusarium spp. in Shanxi Province. [Result] EF-1α was the best gene fragment for identifying Fusarium species among the three candidate gene fragments. Intra-specific pairwise distances was 24 times higher than that of the inter-specific pairwise distances. The intra-specific variation was smaller than those of the inter-specific variation by 73% of the tested species. The accuracy rate for identification was the highest, reached 87%. The phylogenetic relationships derived from the EF-1α sequences showed that different strains in 22 of 27 Fusarium species were monophyly, clustering in a same clade with high supporting values. Among the 27 species of Fusarium, F. oxysporum was the dominant species with 22.1% frequency and covered the largest geographical distribution in the 23 counties or regions in Shanxi Pro

关 键 词：镰孢菌 种群分布 种内种间差异 遗传变异 系统发育分析 

分 类 号：S432.4[农业科学—植物病理学]