Skrede Inger, Eidesen Pernille Bronken, Portela Rosalía Piñeiro, Brochmann Christian
National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172, Blindern, NO-0318 Oslo, Norway.
Mol Ecol. 2006 Jun;15(7):1827-40. doi: 10.1111/j.1365-294X.2006.02908.x.
Many arctic-alpine organisms have vast present-day ranges across Eurasia, but their history of refugial isolation, differentiation and postglacial expansion is poorly understood. The mountain avens, Dryas octopetala sensu lato, is a long-lived, wind-dispersed, diploid shrub forming one of the most important components of Eurasian tundras and heaths in terms of biomass. We address differentiation and migration history of the species with emphasis on the western and northern Eurasian parts of its distribution area, also including some East Greenlandic and North American populations (partly referred to as the closely related D. integrifolia M. Vahl). We analysed 459 plants from 52 populations for 155 amplified fragment length polymorphisms (AFLP) markers. The Eurasian plants were separated into two main groups, probably reflecting isolation and expansion from two major glacial refugia, situated south and east of the North European ice sheets, respectively. Virtually all of northwestern Europe as well as East Greenland have been colonized by the Southern lineage, whereas northwest Russia, the Tatra Mountains and the arctic archipelago of Svalbard have been colonized by the Eastern lineage. The data indicate a contact zone between the two lineages in northern Scandinavia and possibly in the Tatra Mountains. The two single populations analysed from the Caucasus and Altai Mountains were most closely related to the Eastern lineage but were strongly divergent from the remaining eastern populations, suggesting survival in separate refugia at least during the last glaciation. The North American populations grouped with those from East Greenland, irrespective of their taxonomic affiliation, but this may be caused by independent hybridization with D. integrifolia and therefore not reflect the true relationship between populations from these areas.
许多北极 - 高山生物现今在欧亚大陆有着广阔的分布范围，但它们在避难所隔离、分化以及冰期后扩张的历史却鲜为人知。仙女木（广义的八瓣仙女木）是一种长寿的、靠风力传播种子的二倍体灌木，就生物量而言，它是欧亚苔原和石南荒原最重要的组成部分之一。我们着重研究该物种在其分布区的欧亚西部和北部的分化及迁移历史，其中也包括一些东格陵兰和北美种群（部分被归为近缘的全缘叶仙女木）。我们分析了来自52个种群的459株植物的155个扩增片段长度多态性（AFLP）标记。欧亚大陆的植物被分为两个主要类群，这可能反映了它们分别从位于北欧冰盖以南和以东的两个主要冰期避难所隔离并扩张而来。几乎整个欧洲西北部以及东格陵兰都被南方谱系所占据，而俄罗斯西北部、塔特拉山脉以及北极斯瓦尔巴群岛则被东方谱系所占据。数据表明在斯堪的纳维亚北部以及可能在塔特拉山脉存在两个谱系的接触带。从高加索山脉和阿尔泰山脉分析的两个单一种群与东方谱系关系最为密切，但与其余东部种群差异很大，这表明至少在末次冰期期间它们在不同的避难所中存活。北美种群与东格陵兰的种群归为一类，无论它们的分类归属如何，但这可能是由于与全缘叶仙女木独立杂交所致，因此不能反映这些地区种群之间的真实关系。
