Researches Reveal Spatiotemporal Evolution of Reaumuria (Tamaricaceae) in Central Asia: Insights from Molecular Biogeography

Reaumuria, belonging to Tamaricaceae, comprises 12–21 species. The generic distribution center is Central Asia, with taxa extending into western Asia, southern Europe, and northern Africa. However, a taxonomic question exists regarding the genus.

In order to investigate the evolution and dispersal of Reaumuria, LI Kaifeng et al. sampled 18 species of Reaumuria and nine species of two other genera in the Tamaricaceae, Tamarix and Myricaria, and sequenced four markers ITS, rps16, psbB-psbH, and trnL-trnF. They found that the reconstructed phylogenetic tree is fundamentally consistent with previous morphological classification, except that R. soongorica, sometimes considered to be a separate genus or subgenus, is completely nested within Reaumuria.

Their study results suggest that the ancestral area of the genus was western Central Asia, and distributions in the Iran-Mediterranean area and the Tianshan and Pamir-Alai mountains are inferred as dispersals. Westward dispersals to the Iran-Mediterranean were ancient Oligocene to Miocene, whereas dispersals eastward were recent. The spatiotemporal evolution of Reaumuria is used as a link to abiotic paleoclimatic and geological events, in particular, increased aridity beginning at the Eocene-Oligocene Transition (EOT), and as a result of uplift of the Himalayas and Qinghai-Tibet Plateau (QTP).

The results indicate the diversification of the two sections (22.51–19.78 Ma) is a response to increasing aridification with QTP uplift and expansion. The study was published in Phytotaxa in May 2014.