Du Zhi-Yuan, Wang Qing-Feng
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
Sci Rep. 2016 Feb 11;6:20883. doi: 10.1038/srep20883.
In the aquatic genus Stuckenia, the wide geographic range of S. pectinata and S. filiformis make them suited for examination of topographic and climatic effects on plant evolution. Using nuclear ITS sequence and ten chloroplast sequences, we conducted comparative phylogeographical analyses to investigate their distribution regions and hybrid zones in China, and compare their phylogeographical patterns and demographical histories. These two species were allopatric in China. S. filiformis occurred only on the Qinghai-Tibet Plateau (QTP), whereas S. pectinata occupied a wide range of habitats. These two species formed hybrid zones on the northeastern edge of QTP. Most of the genetic variance of S. filiformis was between the southern and eastern groups on the QTP, showing a significant phylogeographic structure. The geographical isolations caused by the Nyenchen Tanglha Mountains and the Tanggula Mountains promoted intraspecific diversification of alpine plants on the QTP. This study revealed the lack of phylogeographic structure in S. pectinata, due to the continued gene flow among its distribution regions. The ecological niche modeling showed that the distribution ranges of these two herbaceous species did not contract too much during the glacial period.
在水生植物狐尾藻属中，篦齿眼子菜和龙须眼子菜广泛的地理分布范围使其适合用于研究地形和气候对植物进化的影响。利用核糖体DNA内转录间隔区（ITS）序列和十个叶绿体序列，我们进行了比较系统地理学分析，以研究它们在中国的分布区域和杂交带，并比较它们的系统地理格局和种群历史。这两个物种在中国是异域分布的。龙须眼子菜仅分布于青藏高原，而篦齿眼子菜占据了广泛的栖息地。这两个物种在青藏高原的东北边缘形成了杂交带。龙须眼子菜的大部分遗传变异存在于青藏高原的南部和东部群体之间，呈现出显著的系统地理结构。念青唐古拉山脉和唐古拉山脉造成的地理隔离促进了青藏高原上高山植物的种内分化。本研究表明，篦齿眼子菜缺乏系统地理结构，这是由于其分布区域之间持续的基因流动所致。生态位建模显示，这两种草本植物在冰期的分布范围并没有大幅收缩。
