|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|2834261||1164302||2010||11 صفحه PDF||سفارش دهید||دانلود رایگان|
Historic events such as the uplift of Qinghai-Tibet Plateau (Q-T Plateau) and climatic oscillations in the Quaternary period greatly affected the evolution and modern distribution of Sino-Tibetan flora. Stellera chamaejasme, a perennial herb with flower color polymorphism that is distributed from the mountainous southeastern Q-T Plateau (Hengduan Mountains, H-D Mountains) to the vast platform of the Q-T Plateau and the adjacent plain of northern China, provides an excellent model to explore the effects of historic events on the origination and variation of species. In this study, we conducted a phylogenetic and phylogeographical study using three chloroplast sequences (trnT-L, trnL-F and rpL16) in 26 populations of S. chamaejasme and 12 outgroups from the Thymeleaceae. Phylogenetic analysis and molecular clock estimation revealed that the monophyletic origin of S. chamaejasme occurred ca. 6.5892 Ma, which is consistent with the radical environment changes caused by the rapid uplift of the Q-T Plateau ca. 7 Ma. Intra-specific differentiation of S. chamaejasme is estimated to have occurred after ca. 2.1 Ma. Twelve haplotypes were revealed from combined trnL-F and rpL16 sequences. High genetic diversity (hT = 0.834) and population differentiation (NST = 0.997 and GST = 0.982) imply restricted gene flow among populations and significant geographical or environmental isolation. All populations from the vast plain of northern China were dominated by one haplotype (H1), and the same haplotype was fixed in most populations from the high elevation platform of the western and northern Q-T Plateau. In contrast, the majority of the haplotypes were found in the relatively narrow area of the H-D Mountains, in the southeastern distribution of S. chamaejasme. The contrasting haplotype distribution patterns suggested that the H-D Mountains were either a refugium for S. chamaejasme during the Quaternary climatic oscillations or a diversification center of this species. The present wide distribution of this species on the Q-T Plateau platform and in northern China is likely to have resulted from a rapid post-glacial population expansion from the southeastern refugium involving founder effects, facilitated by the adjacent geographic range with a similar grassland habitat.
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► The H-D Mountains served as an important glacial refugium for S. chamaejasme.
► Geographical and ecological heterogeneity in the H-D Mountains and the southeastern edge of the Q-T Plateau, together with climatic oscillations during the Quaternary may have promoted intra-specific differentiation and high haplotype richness.
► The current, wide distribution of S. chamaejasme on the Q-T Plateau platform and in northern China may have resulted from rapid post-glacial population expansion from the southeastern refugium.
► The white-red color is the ancestral state for flower color in this flower color polymorphic species
Journal: Molecular Phylogenetics and Evolution - Volume 57, Issue 3, December 2010, Pages 1162–1172