Chloroplast phylogenomics and character evolution of eastern Asian Astragalus (Leguminosae): Tackling the phylogenetic structure of the largest genus of flowering plants in Asia

Astragalus, as the largest genus of flowering plants, is well-known for its high species richness and morphological diversity. Previous studies suggested that many subgenera Astragalus are not monophyletic phylogenetic relationships within still poorly known. In this study, we sampled 117 accessions close relatives, covering 55 sections plus 30 outgroup taxa to recover main clades eastern Asian based on sequences whole chloroplast genome 65 CDSs. supported be it sister Oxytropis + Coluteoid clade. Within recovered ten clades, differ substantially from Bunge’s subgenera. The former segregate Astracantha also monophyletic, but embedded s. str., supporting merge spiny with Astragalus. We detected atpF intron losses in clade, i.e., clade Furthermore, estimated ancestral states trichome morphology habit via Bayesian Binary Method. medifixed hair type inferred have developed at least five times annual originated six times. addition, mid Miocene (stem age, 16.09 Ma, 95% HPD: 12.46–20.50 Ma). divergence groups ranged 4.03 0.87 mostly 2–1 which correlated phased uplifts Qinghai-Tibetan Plateau (QTP). hypothesize QTP, contributed aridification Asia adjacent regions, may accelerated rapid speciation especially xerophilous (i.e. groups).