Adaptive radiation and genetic differentiation in the woodySonchus alliance (Asteraceae:Sonchinae) in the Canary Islands
Adaptive radiation and genetic differentiation in the woodySonchus alliance (Asteraceae:Sonchinae) in the Canary Islands
复制标题
加那利群岛木本Sonchus联盟（菊科：Sonchinae）的适应性辐射和遗传分化
DOI：
10.1007/bf00984650
复制
发表时间：
1999
影响因子：
1.9
通讯作者：
A. Santos‐Guerra
中科院分区：
文献类型：
--
作者：
Seung‐Chul Kim;D. Crawford;J. Francisco‐Ortega;A. Santos‐Guerra
木本苦苣苔属包括苦苣苔属Dendrosonchus亚属19种、苦苣苔属Sonchus亚属Sonchus 1种和5属（Babcockia、Sventenia、Taeckholmia、Lactucosonchus、Prenanthes）种，主要分布于Macaronesian植物地理区的加那利群岛。酶电泳研究，包括13个位点，进行了评估内的遗传多样性和联盟物种之间的分歧。属和/或亚属之间的Nei遗传一致性（距离）范围为0.490（0.714）至0.980（0.013），所有居群的两两比较显示出相对较高的遗传一致性，平均为0.804。高度的同一性进一步支持了联盟的遗传凝聚力及其在Macaronesian群岛上的单一起源。联盟中的物种也显示出约50%的总遗传多样性（HT）高于其他海洋特有种的平均值。有更大的分歧的地方病或物种之间的老岛屿相比，那些年轻的岛屿，这表明，时间是一个因素，在等位酶位点的分歧。此外，老岛屿上的人口有较高的总遗传多样性和较低的身份比年轻的岛屿上的同种种群。这些结果意味着早期的殖民化，辐射，和分歧的woodySonchusalliance在较老的岛屿，随后殖民到年轻的岛屿。等位基因在联盟中的分类学分布表明谱系排序也在物种间的分歧中发挥了作用。谱系分类也可能与分类学命名或从其他分子标记（如nrDNA的ITS序列）获得的变异模式不一致。该联盟的起源和辐射时间与基于ITS序列的估计一致，并表明早期的分歧和快速辐射发生在晚第三纪的大加那利岛或特内里费岛。
The woodySonchusalliance consists of 19 species ofSonchussubg.Dendrosonchus, one species ofSonchussubg.Sonchusand species of five genera (i.e.Babcockia, Sventenia, Taeckholmia, Lactucosonchus, Prenanthes), and is restricted primarily to the archipelago of the Canaries in the Macaronesian phytogeographical region. An enzyme electrophoretic study, including 13 loci, was conducted to assess genetic diversity within and divergence among species of the alliance. Nei's genetic identities (distances) between genera and/or subgenera range from 0.490 (0.714) to 0.980 (0.013), and pairwise comparisons of all populations show relatively high genetic identities, with a mean of 0.804. The high identities further support the genetic cohesiveness of the alliance and its single origin on the Macaronesian islands. Species in the alliance also show about 50%; higher total genetic diversity (HT) than the mean for other oceanic endemics. There is greater divergence between endemics or species on older islands compared to those on younger islands, which suggests that time is a factor for divergence at allozyme loci. Furthermore, populations on older islands have higher total genetic diversities and lower identities than conspecific populations on younger islands. These results imply early colonization, radiation, and divergence of the woodySonchusalliance on older islands followed by subsequent colonization to younger islands. The taxonomic distribution of alleles in the alliance indicates lineage sorting also played a role in divergence among species. Lineage sorting may also produce nonconcordance with either taxonomic designation or the pattern of variation obtained from other molecular markers such as ITS sequences of nrDNA. Timing for the origin and radiation of the alliance agrees with the estimate based on ITS sequences, and suggests that the early divergence and rapid radiation took place during the Late Tertiary on either Gran Canaria or Tenerife.