光柄筒冠花核糖体DNAITS区序列(英文)

Sequence Analyses of ITS Regions of nrDNA from Siphocranion nudipes Kudo (Lamiaceae)

测定了中国特有植物光柄筒冠花（Ｓｉｐｈｏｃｒａｎｉｏｎｎｕｄｉｐｅｓ）的ＩＴＳ区序列，分析了其结构特征、Ｇ＋Ｃ百分含质量（ｗ（Ｇ＋Ｃ）／％）及序列变异性，并比较了光柄筒冠花与其他被子植物的ＩＴＳ区序列特征．光柄筒冠花的ＩＴＳ区和５．８ＳＤＮＡ的总长度为６０９个核苷酸，其中ＩＴＳ－１为２０７ｂｐ，ＩＴＳ－２为２３６ｂｐ，５．８ＳｒＤＮＡ为１６６ｂｐ；总的ｗ（Ｇ＋Ｃ）为５９．１１％，其中ＩＴＳ－１为６４．２５％、ＩＴＳ－２为５７．６３％和５．８ＳｒＤＮＡ为５３．６１％．这一序列的测定为唇形科植物的ＩＴＳ区序列分析及多态性研究打下了基础，同时对进一步研究这一我国特有植物的生态学及物种保护学有着重要意义．这是唇形科ＩＴＳ区序列的首次报道．

The sequence of internal transcribed spacer(ITS) regions of nuclear ribosomal DNA (nrDNA) was determined for the endemic species Siphocranion nudipes (Hemsl ) Kudo (Lamiaceae) from China. This is the first sequence report of the ITS regions for Lamiaceae. The entire ITS and 5 8S regions of Siphocranion nudipes are 609 bases long with an ITS 1 of 207 bp, an ITS 2 of 236 bp and a 5 8S of 166 bp. The overall G+C content was 59 11% with 64 25% in ITS 1, 57 63% in ITS 2, and 53 61% in 5 8S.The numerous copies of the ITS sequences within an individual in Siphocranion nudipes showed a high level of sequence homogeneity and only three nucleotide positions were ambiguous. This sequence will serve as a basis for determining the phylogenetic status of Siphocranion nudipes within Lamiaceae and for indepth studies on the conservation of this endemic species from subtropical areas of China.