Evolutionary radiations in the species-rich mountain genus Saxifraga L.

• DOI: 10.1186/s12862-017-0967-2
• Publication Date: 2017-05-25T13:07:53Z
• Authors: J. Ebersbach; J. Schnitzler; A. Favre; A.N. Muellner-Riehl
• Keywords: Subgenus

A large number of taxa have undergone evolutionary radiations in mountainous areas, rendering alpine systems particularly suitable to study the extrinsic and intrinsic factors that shaped diversification patterns plants. The species-rich genus Saxifraga L. is widely distributed throughout Northern Hemisphere, with high species numbers regions adjacent Qinghai-Tibet Plateau (QTP) particular Hengduan Mountains Himalayas. Using a dataset 297 (representing at least 60% extant species), we explored variation infrageneric rates. In addition, used state-dependent speciation extinction models test effects geographic distribution entire QTP region as well two morphological traits (cushion habit specialized lime-secreting glands, so-called hydathodes) on this genus.We detected three rate shifts across phylogeny these led within subclades Saxifraga, sect. Ciliatae Haworth subsect. Hirculoideae Engl. & Irmsch. Porphyrion Tausch Kabschia GEOSSE analyses showed presence had positive effect Saxifraga. Influence mountains was strongest given its pronounced there, thus radiation group can be classified partially geographic. contrast, evolution cushion life form hydathodes only selected sections, including Kabschia. We therefore argue likely adaptive.Our underlines complexity processes underpinning plant radiations: Even closely related lineages occupying same zone, are not necessarily governed by similar factors. conclusion, result from complex interaction among geographical settings and/or climatic modifications providing key opportunities for innovations.