Phylogeographic testing of alternative histories of single-origin versus parallel evolution of early flowering serpentine populations of Picris hieracioides L. (Asteraceae) in Japan
Phylogeographic testing of alternative histories of single-origin versus parallel evolution of early flowering serpentine populations of Picris hieracioides L. (Asteraceae) in Japan
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日本早期开花蛇纹石种群单一起源与平行进化的系统发育地理学测试
DOI：
10.1007/s11284-017-1536-2
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发表时间：
2018
影响因子：
2
通讯作者：
Ito Motomi
中科院分区：
文献类型：
--
作者：
Sakaguchi Shota;Horie Kenji;Kimura Takuma;Nagano Atsushi J.;Isagi Yuji;Ito Motomi
丝氨酸是一种具有不连续分布的化学极端基质，支持高比例的特有植物物种。在孤立地区的土壤特有种的进化途径可能是平行起源（收敛），但这可能是很难检测到的，由于类似的表型性状重复选择的极端条件下的蛇形环境。测试单一起源与平行进化的蛇形植物种群的替代历史提供了深入了解植物适应极端蛇形环境和分散在孤立的蛇形区域之间的能力。本研究以中药毛苦苣菜Picris hieracioidesL.（菊科），其中包括早开花的蛇纹种群周围的开花较晚，非蛇纹种群的北海道，日本。我们进行了群体遗传分析的基础上，全基因组SNP标记和量化的时间重叠的开花时间在自然条件下。系统地理学分析证实了两个遗传组的发生，对应于蛇纹和非蛇纹种族。虽然这两个种族被发现发生在密切parapatry多对土壤网站，杂交的证据很少被检测到。两个小种的开花时间差异显著，开花高峰相隔1个月以上。总体而言，这项研究支持serpentinePicris种群的单一起源，并显示了不同的开花时间作为一个强大的前合子障碍，以保持在短的空间距离的土壤种族的作用。
Serpentine, a chemically extreme substrate with a discontinuous distribution, supports a high proportion of endemic plant species. The evolutionary pathway of edaphic endemics in isolated areas may be of parallel origin (convergence), but this can be difficult to detect due to similar sets of phenotypic traits repeatedly selected for by the extreme conditions of serpentine environments. Testing the alternative histories of single origin vs. parallel evolution in serpentine plant populations provides insight into the ability of plants to adapt to extreme serpentine environments and to disperse between isolated serpentine areas. In this study, we focused on the herbPicris hieracioidesL. (Asteraceae), which includes early-flowering serpentine populations surrounded by later flowering, non-serpentine populations on Hokkaido Island, Japan. We performed population genetic analysis based on genome-wide SNPs markers and quantified temporal overlap of flowering times under natural conditions. Phylogeographic analysis confirmed the occurrence of two genetic groups, corresponding to the serpentine and non-serpentine races. Although the two races were found to occur in close parapatry over multiple paired soil sites, little evidence for hybridization was detected. The flowering times of the two races showed significant divergence, with flowering peaks separated by more than 1 month. Overall, this study supported the single origin of serpentinePicrispopulations, and showed the role of divergent flowering time as a strong prezygotic barrier to maintain the edaphic races over short spatial distances.