红景天线粒体nad7基因内含子2序列测定及其系统发育意义

Identification and phylogenetic application of unique nucleotide sequence of nad7 intron2 in Rhodiola (Crassulaceae) species

开展濒危藏药红景天的分子生物学研究,可以为红景天遗传资源鉴定与保护提供指导。利用线粒体中nad7基因的保守序列设计的引物,对分布于四川的大花红景天、长鞭红景天和吉林的高山红景天等9份材料进行PCR分析,发现在所有的红景天材料中均获得约800bp的扩增产物。进一步对扩增片段进行序列测定,结果表明该片段除具有53bp的外显子区外,其内含子长度均为738bp,有9个核苷酸变异位点。将测定序列进行比对和聚类分析表明,红景天线粒体nad7内含子2序列被单独聚类。而且测定的红景天的nad7内含子2序列,其长度均小于其他高等植物的同源序列,体现了红景天属植物的该基因区域的特异性,可能与特殊的生态环境有关。

Genetic characterization of 9 populations of Rhodiola crenulata, R. fastigiata and R. sachalinensis （Crassulaceae） species from Sichuan and Jilin Provinces of China, was investigated using the conserved primer of nad7 intron 2. All PCR products about 800 bp long were shorter than other Crassulaceae plants, which were used as molecular markers to identify the Rhodiola species. The sequence of the products indicated that total exon of 53 bp and intron of 738 bp exhibit only 9 nucleotide variations. Blasting the had7 sequences to GenBank and the phylogenetic analysis showed that the sequence of Rhodiola species was clusted independently, and the length was smaller than all the registered sequences of higher plants. The result suggests that the Rhiodola species had a unique sequence in this gene region, which might be related to the special growth condition.