海南普通野生稻不同居群rDNA ITS区序列的比较分析

Comparison and Analysis of Ribosomal DNA ITS Sequence of Common Wild Rice from Different Geographical Regions in Hainan

以转bar基因粳稻(O. sativa ssp. japonica)YOO3为外类群,采用PAUP4.0等软件,对海南7个主要普通野生稻(O. rufipogon)核糖体基因(nrDNA)的内转录间隔区(ITS)全序列信息进行比较分析。结果表明,ITS全长为586～589 bp,其中ITS1为193～195 bp,共有20个变异位点数,G/C含量为72.02%～74.74%;ITS2为229～231 bp,共有12个变异位点数,G/C含量为75.55%～76.08%;离栽培稻越近的类群G/C含量越高。所有材料5.8S rDNA序列完全一致,全长164 bp,G/C占97 bp,含量为59.15%。各类群间ITS序列信息较丰富,且显示ITS1比ITS2进化速度要快。利用ITS差异信息序列进行聚类分析为鉴别不同居群的普通野生稻提供了分子依据。

The complete internal transcribed spacers （ITS） of nuclear ribosomal DNA of 7 main common wide rice （Oryza rufipogon） populations from Hainan, China were amplified using Polymerase Chain Reaction （PCR） technique, cloned and sequenced, with O. sativa ssp.japonica Y003 as outgroup, and resultant data were analyzed by using a biology software PAUP4.0. The results demonstrated that the sequences of ITS ranged from 586 bp to 589 bp. The sequences of ITS1 ranged from 193 bp to 195 bp in size with 20 variable sites, G/C content varied from 72.02 % to 74.74 %; the sequences of ITS2 ranged from 229 bp to 231 bp in size with 12 variable sites, G/C content varied from 75.55 % to 76.08 %, and; G/C content of ITS sequences were higher in the wild rice which were more similar to the cuhivar rice. The 5.8S rDNA length and G/C content of all the populations of the common wide rice were completely the same, 164 bp in size and 97 bp in G/C or 59.15 % in G/C content. There was abundant sequence information among Hainan common wild rice, and ITS1 sequences had higher speed of evolution than ITS2 sequences. Cluster analysis of the ITS differential information sequence offers molecular basis for identifying O. rufipogon from different population regions according to the variation in phylogenetics of the ITS sequences.