The Tibeto-Himalayan region, comprising the Qinghai-Tibetan Plateau (QTP), the Himalayas and the Hengduan Mountains, is one of the major hotspots for cold-adapted plant lineages. Parts of the QTP may have reached 4000 m elevation as early as 40 million years ago. The Hengduan Mountains on the other hand are considered relatively young, forming about 3 million years ago, and only reached significant elevation during the Pleistocene, 2.6 million to 11,700 years ago.
The different geological histories of the QTP and the Hengduan Mountains have resulted in contrasting plant evolutionary patterns in each area. However, questions remain about the evolutionary patterns of taxa in the junction between these two regions.
In their new paper published in AoBP, Fu et al. describe a new species – Gentiana hoae P.C. Fu & S.L. Chen – from the Qinghai-Tibetan Plateau and explore its evolutionary history in this region. Gentiana is an alpine genus encompassing around 360 species, with the QTP acting as the primary source region for dispersal to numerous mountain systems across the world.
Pleistocene glaciations are suggested as a key factor shaping the population history of G. hoae. Phylogenetic analysis suggests that G. hoae participated in historical hybridization, while population sequencing show this species continues to hybridize with the co-occurring congener G. straminea in three locations. Our results indicate that hybridization may be a common process in the evolution of Gentiana and may be widespread among recently diverged taxa of the QTP.