基于叶绿体DNA ndhA和nrDNA ITS序列变异分析栽培柿及其近缘种亲缘关系

以柿属植物（Diospyros spp.）中与柿近缘的8种共30个基因型为试材，进行核糖体DNA(nrDNA)内转录间隔区（ITS）和叶绿体DNA ndhA序列变异分析，并通过软件计算两个序列及合并后的进化模型，依据进化模型采用ML法(maximum likelihood method)分析进化关系。为进一步弄清柿属植物种间亲缘关系和供试柿（Diospyros kaki Thunb.）种内分子差异提供了理论依据。结果表明：（1）ndhA序列长度变异范围在1 492~1 511，14个信息位点；ITS序列长度变异范围在660~761，56个信息位点。ITS、ndhA和ndhA+ITS（ndhA和ITS合并）最适碱基进化模型分别为（TrN+I+G）、（F81+I）和（GTR+I+G）。综合ITS和ndhA序列分析表明：柿与油柿和云南野毛柿亲缘关系最近，与美洲柿和乌柿最远。（2）21份柿品种材料的ITS长度均为730，包括4个变异位点，据此4个变异位点对供试柿种内21个品种进行聚类分析。研究认为，ndhA和ITS能较清楚解释了柿与其近缘种间的亲缘关系，并通过柿品种ITS的差异位点分析鉴别出栽培柿种内的差异。

Sequence Analysis of ITS Regions and ndhA Gene for Determining Phylogenetic Relationship of Diospyros kaki(persimmon) With Other Related Wild Diospyros(Ebenaceae) Species

We used eight species(30 genotypes) of Diospyros spp. to study the interspecific relationship and intraspecific variation by ndhA and ITS sequences for calculating substitution model of two sequence and their combination, and then building three phylogenetic trees constructed by ML method based model parameters. The length range of ndhA sequence were 1492 to 1511, 14 informative sites, and the length range of ITS sequence were 660 to 761, 56 informative sites. The best fit models of ITS, ndhA and ndhA+ITS were(TrN+I+G), (F81+I) and (GTR+I+G), respectively. D.kaki was closely related to D.oleifera and D.artrotricha, but distant from D.virginiana and D.cathayensis. The length of D.kaki cultivar was 730, including four variation sites. We analyzed the genetic diversity of selected 21 D.kaki cultivars based on four variation sites. The results suggested that ndhA and ITS sequence variation analysis could explain the relationship between D.kaki and its related species, and the intraspecific variation could be analyzed according to four variation sites.