论文部分内容阅读
目的构建碎米桠Isodon rubescens及其与近缘种之间系统发育关系,准确鉴别碎米桠及其近缘种。方法提取碎米桠及其近缘种DNA,对核基因ITS片段和叶绿体基因psbA-trnH序列扩增和测序,计算物种种内、种间Kimura 2-paramete(rK2P)遗传距离。采用最近距离、相似性搜索、构建Neighbor-joining(NJ)系统聚类树3种方法进行鉴定分析。结果 ITS和psbA-trnH分子系统树支持碎米桠5个居群样本聚为一单系分支,支持率为94%和68%;其中,碎米桠与毛叶香茶菜、香茶菜和内折香茶菜聚在一支,支持率为70%和51%;溪黄草和显脉香茶菜构成姐妹群分支,支持率为81%和63%。碎米桠及其近缘种种间ITS和psbA-trnH序列的K2P遗传距离为0.007 08~0.072 61和0.008 06~0.024 76,均远大于碎米桠种内的遗传距离0~0.001 76和0~0.002 68。结论碎米桠与毛叶香茶菜、香茶菜和内折香茶菜亲缘关系较近,溪黄草和显脉香茶菜亲缘关系最近。ITS和psbA-trnH序列可以准确鉴别碎米桠及其近缘种。
Objective To construct the phylogenetic relationship between Isodon rubescens and its related species, and to identify the breed and its related species accurately. Methods DNA was extracted from rice grains and its related species. The ITS fragment of chloroplast gene and the psbA-trnH gene of chloroplast were amplified and sequenced. The genetic distances between species and inter-species Kimura 2-paramete (rK2P) were calculated. Neighbor-joining (NJ) phylogenetic tree was constructed based on nearest distance and similarity search. Results The ITS and psbA-trnH molecular phylogenetic trees supported five populations of M. brevicaulus as a single branch with support rates of 94% and 68%, respectively. Among them, Within the folding incense Chaka gathered in a support rate of 70% and 51%; Xihuangcao and Xian Mai tea constitute the sister group branches, the support rate was 81% and 63%. The K2P genetic distances of ITS and psbA-trnH sequences among the breeds and their relatives ranged from 0.007 08 to 0.072 61 and from 0.0086 to 0.02476, both of which were far greater than the genetic distances of 0 to 0.001 76 and 0 ~ 0.002 68. Conclusion There is a close genetic relationship between broken rice gourd and the fragrant tea leaves, fragrant green tea and inflorescence fragrant green tea, and the closest genetic relationship between Xihuangcao and Xianmaixian green tea. ITS and psbA-trnH sequences can accurately identify breeds and their related species.