Abstract
We investigated the phylogenetic and biogeographic relationships of natural populations of diploid and tetraploid Fagopyrum cymosum (Polygonaceae). Intraspecific variation of chloroplast DNA sequences was detected in three regions approximately 5 kb long in total: the 3' end of rbcL, accD and associated intergenic spacer region, the trnC (GCA)-rpoB spacer region, the trnK (UUU) intron, and the matK region. The accessions of F. cymosum were divided into two major groups, a Tibet-Himalayan clade and a Yunnan-Sichuan clade, with a high bootstrap probability. It was estimated that these two clades diverged about 0.7 million years ago. The geographical and climatic interruption by the Hengduanshan mountains might have caused the genetic divergence in F. cymosum. Autotetraploid populations of F. cymosum have arisen allopatrically from a diploid progenitor at least twice, once in the Tibet-Himalayan area and once in the Yunnan-Sichuan area. This conclusion reinforces a previous study based on allozyme variation. We also found that F. tataricum, a close relative of F. cymosum, was completely included within the Tibet-Himalayan clade in the phylogenetic tree. This suggests that F. tataricum speciated from F. cymosum in the Tibet-Himalayan area.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
