Department of Agricultural Sciences , University of Helsinki , PO Box 27 (Latokartanonkaari 5), Helsinki FI-00014 , Finland.
AoB Plants. 2013;5:plt024. doi: 10.1093/aobpla/plt024. Epub 2013 May 2.
We investigated patterns of genetic variability in Saxifraga oppositifolia in the isolated Arctic Svalbard archipelago. The genetic analysis included genotyping using nine polymorphic microsatellite markers and sequencing of the nuclear internal transcribed spacer region. Among populations, mean allele numbers per microsatellite locus ranged from 2.0 to 2.6, and 9 % of alleles were unique. Observed (H O) and expected (H E) heterozygosities averaged 0.522 and 0.445, respectively. Typically negative but non-significant F IS values (mean -0.173) were found in S. oppositifolia populations. F ST values were relatively low (mean 0.123). The Bayesian structure analysis provided additional information on population genetic structures. Seven out of 11 studied populations, including populations located both near each other and far apart (distances 5-210 km), showed relatively homogeneous clustering patterns, while one population located on a slope in the main settlement of Longyearbyen possessed a unique genetic structure. The Mantel test proved that there is no significant correlation between genetic and geographical distances. Different growth habits (compact, trailing and intermediate) did not possess distinct genetic compositions based on microsatellite variation. Internal transcribed spacer sequencing revealed 12 polymorphic sites. Among 24 sequenced Svalbard samples, eight haplotypes were detected, none shared by the mainland samples. Population genetic structures of S. oppositifolia in Svalbard show that both genetic variation and differentiation levels are modest, outcrossing is the main mating system, and dispersal and gene flow are important, probably attributable to strong winds and human and animal vectors.
我们研究了孤立的北极斯瓦尔巴群岛上虎耳草属植物的遗传变异模式。遗传分析包括使用 9 个多态微卫星标记进行基因分型和核内转录间隔区的测序。在种群中，每个微卫星位点的平均等位基因数为 2.0 到 2.6，9%的等位基因是独特的。观察到的（H O）和预期的（H E）杂合度分别平均为 0.522 和 0.445。在虎耳草属植物种群中发现了典型的负但非显著的 F IS 值（平均值为-0.173）。F ST 值相对较低（平均值为 0.123）。贝叶斯结构分析提供了关于种群遗传结构的额外信息。在所研究的 11 个种群中，有 7 个种群，包括位于彼此附近和遥远的种群（距离为 5-210 公里），表现出相对均匀的聚类模式，而一个位于朗伊尔城主要定居点斜坡上的种群具有独特的遗传结构。Mantel 检验证明遗传距离与地理距离之间没有显著的相关性。不同的生长习性（紧凑、拖曳和中间）在基于微卫星变异的遗传组成上没有明显的区别。内部转录间隔区测序显示有 12 个多态性位点。在所测序的 24 个斯瓦尔巴特样本中，检测到 8 种单倍型，其中没有一种与大陆样本共享。斯瓦尔巴特群岛上虎耳草属植物的种群遗传结构表明，遗传变异和分化水平都适中，异交是主要的交配系统，扩散和基因流是重要的，这可能归因于强风和人类和动物载体。
