Koch Marcus A, Kiefer Christiane, Ehrich Dorothee, Vogel Johannes, Brochmann Christian, Mummenhoff Klaus
University of Heidelberg, Institute of Plant Sciences, Division of Biodiversity and Plant Systematics, Germany.
Mol Ecol. 2006 Mar;15(3):825-39. doi: 10.1111/j.1365-294X.2005.02848.x.
Arabis alpina is a characteristic plant in arctic-alpine habitats and serves as a classical example to demonstrate biology, ecology and biogeography of arctic-alpine disjuncts. It has a wider distribution than most other arctic-alpine plants, covering all European mountain systems, the Canary Islands, North Africa, the high mountains of East Africa and Ethiopia, the Arabian Peninsula and mountain ranges of Central Asia in Iran and Iraq. Additionally it is found in the northern amphi-Atlantic area including northeastern North America, Greenland, Iceland, Svalbard and northwestern Europe. We used markers from the nuclear (internal transcribed spacer of ribosomal DNA) and chloroplast genome (trnL-F region) to reconstruct its phylogeographic history. Both markers revealed clear phylogeographic structure. We suggest that A. alpina originated in Asia Minor less than 2 million years ago based on synonymous mutation rates of different genes (plastidic matK, nuclear adh and chs). From the Asian ancestral stock one group migrated via the Arabian Peninsula to the East African high mountains. A second group gave rise to all European and northern populations, and also served as source for the northwest African populations. A third group, which is still centred in Asia, migrated independently southwards and came into secondary contact with the East African lineage in Ethiopia, resulting in high genetic diversity in this area. In the Mediterranean regions, the genetic diversity was relatively high with numerous unique haplotypes, but almost without geographic structure. In contrast, the populations in the northern amphi-Atlantic area were extremely depauperate, suggesting very recent (postglacial) expansion into this vast area from the south.
高山南芥是北极-高山栖息地的一种典型植物，是用以阐释北极-高山间断分布植物的生物学、生态学和生物地理学的经典实例。它的分布范围比大多数其他北极-高山植物都要广，覆盖了所有欧洲山脉系统、加那利群岛、北非、东非和埃塞俄比亚的高山、阿拉伯半岛以及伊朗和伊拉克的中亚山脉。此外，在北大西洋两岸地区也有发现，包括北美东北部、格陵兰岛、冰岛、斯瓦尔巴群岛和欧洲西北部。我们使用来自核基因组（核糖体DNA的内转录间隔区）和叶绿体基因组（trnL-F区域）的标记来重建其系统发育地理历史。这两种标记都揭示了清晰的系统发育地理结构。基于不同基因（质体matK、核adh和chs）的同义突变率，我们认为高山南芥在不到200万年前起源于小亚细亚。从亚洲祖先种群中，一组经由阿拉伯半岛迁移到东非高山。第二组产生了所有欧洲和北部的种群，也是西北非种群的来源。第三组仍以亚洲为中心，独立向南迁移，并在埃塞俄比亚与东非谱系发生二次接触，导致该地区具有高遗传多样性。在地中海地区，遗传多样性相对较高，有许多独特的单倍型，但几乎没有地理结构。相比之下，北大西洋两岸地区的种群极度匮乏，表明它们是最近（冰期后）才从南方扩张到这片广阔区域的。
