几个中国大麦属物种核rDNAITS区序列分析

Sequence Analysis of the ITS Region of Nuclear Ribosomal DNA in Some Hordeum Species from China

对8份来源于中国和7份国外的不同大麦属物种核rDNAITS区进行了序列分析,并采用邻接法构建了其系统发育树状图。结果表明,大麦属物种的ITS区序列长度为596～600bp,其中ITS1、5.8S和ITS2分别有43、4和54个变异位点。ITS区揭示的遗传分化距离变化范围为0～0.1121,平均值为0.0561。以雀麦属为外类群,采用邻接法进行系统发育关系分析发现,大麦属不同物种间聚类关系与其地理来源无关;各物种或亚种按照其亲缘关系与染色体组的划分进行聚类,其中具有H和I染色体组的物种各聚为一个分支。

The internal transcribed spacer (ITS) of nuclear ribosomal DNA (nrDNA) in 8 and 7 species or subspecies of Hordeum from China and other countries, respectively, were investigated by PCR amplification and direct sequencing. The length of the entire ITS region of the Hordeum species or subspecies varies from 596 to 600?bp. The numbers of variable sites are 43, 4 and 54 in ITS 1, 5.8 S and ITS 2, respectively. The ITS sequence divergence is very low, ranging from 0 to 0.1121 with the mean of 0.0561. Using Bromus tectorum L. as outgroup, phylogenetic relationships among 13 species or subspecies in Hordeum are estimated by neighbor-joining method. It indicates that the phylogenetic relationships in Hordeum are not closely related with its geographical distribution, while closely related with its genome constitution. The species or subspecies, which have the H genome, are closely related and have the tendency to cluster into the same group, and divergent from the species or subspecies, which have the I genome.