Panax stipuleanatus(Araliaceae) is an endangered and medicinally important plant endemic to China.However, phylogenetic relationships within the genus Panax have remained unclear. In this study, we sequenced the complete plastome of P. stipuleanatus and included previously reported Panax plastomes to better understand the relationships between species and plastome evolution within the genus Panax.The plastome of P. stipuleanatus is 156,069 base pairs(bp) in length, consisting of a pair of inverted repeats(IRs, each 25,887 bp) that divide the plastome into a large single copy region(LSC, 86,126 bp) and a small single copy region(SSC, 8169 bp). The plastome contains 114 unigenes(80 protein-coding genes,30 tRNA genes, and 4 r RNA genes). Comparative analyses indicated that the plastome gene content and order, as well as the expansion/contraction of the IR regions, are all highly conserved within Panax. No significant positive selection in the plastid protein-coding genes was observed across the eight Panax species, suggesting the Panax plastomes may have undergone a strong purifying selection. Our phylogenomic analyses resulted in a phylogeny with high resolution and supports for Panax. Nine proteincoding genes and 10 non-coding regions presented high sequence divergence, which could be useful for identifying different Panax species.
Changkun LiuZhenyan YangLifang YangJunbo YangYunheng Ji
水鳖科（Hydrocharitaceae）海菜花（Ottelia acuminata）是中国西南地区特有的水生单子叶植物.基于AFLP技术的磁珠富集快速分离技术（Fast Isolation by AFLP of Sequences Containing Repeats,FIAS-CO）,共筛选出9对多态性引物并对3个居群45个个体进行分析.结果表明：三个居群的等位基因数目为1~3个,观测杂合度从0．000~0．933,期望杂合度从0．000~0．605.这些筛选出的微卫星引物将用于海菜花后续的谱系地理学和生态遗传学研究.
