青藏高原植物手参的谱系地理学研究

Phylogeography of Gymnadenia conopsea from the Qinghai-Tibet Plateau

利用叶绿体基因(rbcl和psb A-trn H)对青藏高原地区的10个手参(Gymnadenia conopsea)种群进行谱系地理学研究,旨在揭示手参的遗传谱系分布格局及其演化过程。结果表明,共得到11个单倍型,分子方差分析显示65.93%的遗传变异来源于种群间,FST值为0.659(P<0.01),种群间存在显著的遗传分化;遗传分化系数NST(0.398)小于GST(0.626),说明青藏高原地区的手参没有明显的谱系地理结构;多峰的失配分析曲线和Tajima’s D中性检验(-1.455,P>0.1)表明手参种群近期没有经历扩张;系统发育分析和分歧时间估计表明,现代青藏高原上的手参为本地起源,手参单倍型在19.08 Mya的第三纪中新世时期开始分化,与青藏高原隆起关系密切,青藏高原上手参的遗传分布格局在第四纪冰期之前已基本形成。

Chloroplast DNA（rbcl and psb A-trn H）of Gymnadenia conopsea（G. conopsea）from the Qinghai-Tibet Plateau was usedfor phylogeography research,aiming at revealing the distribution pattern and evolutional process of genetic lineage of G. conopsea. Elevenhaplotypes were identified in 199 samples of 10 G. conopsea populations. The analysis of molecular variance（AMOVA）showed 65.93% of thegenetic variance was from inter-populations and FST value of 0.659（P〈0.01）also indicated that there was significant genetic differentiationbetween different populations. The genetic differentiation coefficients NST（0.398） GST（0.626）implied no significant phylogeographicstructure for G. conopsea populations in the Qinghai-Tibet Plateau. Mismatch analysis of multi-peak and Tajima＇s D neutral test（-1.455,P〈0.1）demonstrated G. conopsea populations had not experienced abrupt expansion recently. Phylogenetic analysis and divergence timeestimation showed that G. conopsea in the Qinghai-Tibet Plateau originated indigenously,haplotypes started to differentiate 19.08 million yearsago（Mya）in Miocene,indicating that the genetic differentiation of G. conopsea was related to the uplift of the Qinghai-Tibetan Plateau,andthe genetic distribution pattern of G. conopsea was mostly formed before the Quaternary glaciation.