Resurrection of Stipatremula and taxonomy of the high-alpine species from the Stipapurpurea complex (Poaceae, Pooideae)

Elucidation of the evolutionary history of Stipa in China using comparative transcriptomic analysis

Phylogenetic analysis provides crucial insights into the evolutionary relationships and diversification patterns within specific taxonomic groups. In this study, we aimed to identify the phylogenetic relationships and explore the evolutionary history of Stipa using transcriptomic data. Samples of 12 Stipa species were collected from the Qinghai-Tibet Plateau and Mongolian Plateau, where they are widely distributed, and transcriptome sequencing was performed using their fresh spikelet tissues. Using bidirectional best BLAST analysis, we identified two sets of one-to-one orthologous genes shared between Brachypodium distachyon and the 12 Stipa species (9397 and 2300 sequences, respectively), as well as 62 single-copy orthologous genes. Concatenation methods were used to construct a robust phylogenetic tree for Stipa, and molecular dating was used to estimate divergence times. Our results indicated that Stipa originated during the Pliocene. In approximately 0.8 million years, it diverged into two major clades each consisting of native species from the Mongolian Plateau and the Qinghai-Tibet Plateau, respectively. The evolution of Stipa was closely associated with the development of northern grassland landscapes. Important external factors such as global cooling during the Pleistocene, changes in monsoonal circulation, and tectonic movements contributed to the diversification of Stipa. This study provided a highly supported phylogenetic framework for understanding the evolution of the Stipa genus in China and insights into its diversification patterns.

First insight into the phylogeny of fine‐leaved Festuca in the Altai Mountain Country based on genome‐wide genotyping

Festuca is one of the largest genera within the Poaceae family. Molecular phylogenies demonstrate that Festuca s.l. comprises two groups: broad‐ and fine‐leaved species. The latter is the species‐richest and taxonomically complicated group due to being paraphyletic. Here, we provide the first insight into the phylogeny of 17 fine‐leaved species of Altai fescues. Based on genome‐wide genotyping, the examined taxa were divided into three markedly differentiated clusters. The first cluster comprises species from the F. rubra complex, the second cluster includes the F. brachyphylla complex, and the third cluster contains taxa from the groups F. ovina, F. valesiaca, and F. kryloviana. Importantly, we detected a complex genetic pattern within the groups of F. valesiaca and F. kryloviana. Moreover, our findings underline a discrepancy between morphological and molecular data for some species distributed within the Altai Mountain Country. We suggest that in order to validate the current findings on the fine‐leaved fescues, additional comprehensive research including morphological, karyological, and molecular methods is required. Nonetheless, our work provides a baseline for further investigations on the genus and studies on the floral diversity of Asia.