Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University Uppsala, Sweden.
Ecol Evol. 2013 Sep;3(10):3320-33. doi: 10.1002/ece3.698. Epub 2013 Aug 15.
Taiwan spruce (Picea morrisonicola) is a vulnerable conifer species endemic to the island of Taiwan. A warming climate and competition from subtropical tree species has limited the range of Taiwan spruce to the higher altitudes of the island. Using seeds sampled from an area in the central mountain range of Taiwan, 15 nuclear loci were sequenced in order to measure genetic variation and to assess the long-term genetic stability of the species. Genetic diversity is low and comparable to other spruce species with limited ranges such as Picea breweriana, Picea chihuahuana, and Picea schrenkiana. Importantly, analysis using approximate Bayesian computation (ABC) provides evidence for a drastic decline in the effective population size approximately 0.3-0.5 million years ago (mya). We used simulations to show that this is unlikely to be a false-positive result due to the limited sample used here. To investigate the phylogenetic origin of Taiwan spruce, additional sequencing was performed in the Chinese spruce Picea wilsonii and combined with previously published data for three other mainland China species, Picea purpurea, Picea likiangensis, and P. schrenkiana. Analysis of population structure revealed that P. morrisonicola clusters most closely with P. wilsonii, and coalescent analyses using the program MIMAR dated the split to 4-8 mya, coincidental to the formation of Taiwan. Considering the population decrease that occurred after the split, however, led to a much more recent origin.
台湾云杉（Picea morrisonicola）是一种脆弱的针叶树种，仅分布于台湾岛。气候变暖以及亚热带树种的竞争，使得台湾云杉的分布范围仅限于该岛的高海拔地区。本研究从台湾中央山脉的一个地区采集种子，对 15 个核基因座进行了测序，以测量遗传变异并评估该物种的长期遗传稳定性。遗传多样性较低，与其他分布范围有限的云杉物种（如 Picea breweriana、Picea chihuahuana 和 Picea schrenkiana）相当。重要的是，近似贝叶斯计算（approximate Bayesian computation，ABC）分析提供了证据，表明该物种的有效种群数量在大约 0.3-0.5 百万年前（mya）急剧下降。我们使用模拟表明，由于此处使用的样本有限，这不太可能是假阳性结果。为了探究台湾云杉的系统发育起源，我们对中国云杉 Picea wilsonii 进行了额外的测序，并与之前发表的中国大陆的另外三个物种（Picea purpurea、Picea likiangensis 和 P. schrenkiana）的数据相结合。种群结构分析表明，P. morrisonicola 与 P. wilsonii 聚类最紧密，使用程序 MIMAR 进行的合并分析将其分裂时间定在 4-8 mya，与台湾的形成时间巧合。然而，考虑到分裂后种群数量的减少，导致了一个更近的起源时间。
