Phylogeographic study of Musella lasiocarpa (Musaceae): providing insight into the historical river capture events

摘要

In the late Pliocene, the Qinghai-Tibet plateau experienced several rapid uplifts. The resulting Hengduan Mountains have since played an important role in the plant distribution pattern in China. Here, a phylogeographic study on wild populations of Musella lasiocarpa (Musaceae), which is endemic to southwest China, is reported. We have discovered 9 wild populations of M. lasiocarpa throughout its natural distribution in cliff habitats in southwest China since 2004. In order to reveal the factors causing the current distribution pattern of wild M. lasiocarpa populations and its spread pathways , phylogenetic analysis by s equencing 3 chloroplast DNA fragments ( psbA-trnH , trnL-F and rpl16 ) were performed. Based on the results, we deduced that the origin of wild M. lasiocarpa populations was in the region of the Lijiang aera of the Jinsha River, which was close to Yanbian, Panzhihua. The differentiation was probably caused by the uplift of the Qinghai-Tibet Plateau, the Hengduan Mountain orogeny, and the westward retreat of the ancient Mediterranean Sea. The main factors that contributed to the fragmentation of wild M. lasiocarpa population habitat include diversion of the ancient Red River and stream capture of its tributaries.