Phylogeography of Hippophae neurocarpa (Elaeagnaceae) inferred from the chloroplast DNA trnL-F sequence variation
Phylogeography of Hippophae neurocarpa (Elaeagnaceae) inferred from the chloroplast DNA trnL-F sequence variation
复制标题
DOI：
--
复制
发表时间：
2008
影响因子：
3.7
通讯作者：
M. Key
中科院分区：
文献类型：
--
作者：
M. Key
第四纪气候振荡期间青藏高原的地形效应必然对生物的空间分布和遗传结构产生重要影响。与此同时，高原隆升提供的生态位和随后的第四纪气候变化可能促进了那里植物的形态分化和物种形成。神经果沙棘（Hippophae neurocarpa）是高原特有的胡颓子科植物，是沿着分布的优势灌木，也分布于半干旱生态系统中。该物种被认为是两个独立的亚种，即ssp。neurocarpa和ssp. stellatopilosa，主要是根据叶片上的附属物和不同的栖息地偏好。前者叶上具鳞片状附属物，分布于较干燥和寒冷的生境;后者叶上具星状毛，喜生于较湿润和温暖的生境。这是有趣的是，知道是否形态亚种H。neurocarpa与种内叶绿体发生有关。此外，该物种也提供了一个很好的替代品，以检验假说，少数耐寒或耐旱物种生存在高原的高海拔地区在第四纪冰期。在这项研究中，我们研究了叶绿体trnL-F序列的变化，从两个亚种的H。脉果属叶绿体基因组被发现是母系遗传的沙棘和种内系谱可能反映了母系血统排序两个亚种之间。通过对来自14个群体的70个个体进行测序，共回收了8种单倍型。一个是两个亚种共有的，四个和三个只在ssp中发现。neurocarpa和ssp. stellatopilosa分别。这些结果表明，两个亚种没有表现出系谱一致的形态分化在这个片段。构建的巢式进化树将8个单倍型分为3个谱系：一个是ssp特有单倍型。neurocarpa和其他两个包括来自两个亚种的单倍型与ssp。尖部为脉果。此外，在高海拔地区发现的独特单倍型表明该物种可能在这些干旱的生境中生存。从这些不同的避难所检测到的连续范围扩大。
The topological effect of the Qinghai-Tibetan Plateau during the Quaternary climatic oscillation must have important effects on spatial distribution and genetic structure of organisms distributed there. At the same time, the ecological niches provided by the uplifts of the plateau and the following Quaternary climatic changes may have promoted morphological differentiation and speciation of plants occurring there. The plateau endemic Hippophae neurocarpa (Elaeagnaceae) is a dominant shrub species along the streams or rivers and it also occurs in the semiarid ecosystem. This species is recognized as two separate subspecies, i.e. ssp. neurocarpa and ssp. stellatopilosa, mainly according to the appendages on leaves and different habitat preferences. The former is characteristic of scale-like appendages on the leaves and distributed in the drier and colder habitats while the latter has stellate hairs with a preference of occurring in the wetter and warmer habitats. It is interesting to know whether the morphological sub-speciation of H. neurocarpa is correlated with the intra-specific chloroplast phylogeny. In addition, this species also provide a good proxy to test the hypothesis that a few cold- or dry-tolerating species survive in the high altitude region of the plateau during the Quaternary glacial stages. In this study, we examined chloroplast trnL-F sequence variation from both subspecies of H. neurocarpa. The chloroplast genome was found to be maternally inherited in Hippophae and the intraspecific genealogy may reflect the maternal lineage sorting between both subspecies. A total of eight haplotypes were recovered through sequencing 70 individuals from 14 populations. One was shared by both subspecies, and four and three were only found in ssp. neurocarpa and ssp. stellatopilosa respectively. These findings suggested that two subspecies did not show genealogical concordance with morphological differentiation in this fragment. The constructed nested cladogram classified eight haplotypes into three lineages: one consisted of endemic haplotypes of ssp. neurocarpa and the other two included haplotypes from both subspecies with those of ssp. neurocarpa at the tip positions. In addition, the unique haplotypes recovered in the high altitude suggested that this species might have survived in these arid habitats. The contiguous range expansion was detected from these different refugia.