Phylogenomic analyses support a new infrageneric classification of Pourthiaea (Maleae, Rosaceae) using multiple inference methods and extensive taxon sampling

In this comprehensive study, based on extensive taxon sampling, we performed phylogenomic analyses of plastome and nuclear ribosomal DNA (nrDNA) datasets. We employed multiple inference methods, including concatenated and coalescent-based strategies, to generate an accurate phylogeny of the woody Rosaceae genus Pourthiaea. The nrDNA phylogeny of Pourthiaea strongly supports three major clades, which are consistent with morphology. However, the plastid tree provides an alternative phylogenetic topology, indicating cytonuclear discordance which could be explained by frequent hybridizations between and among the species of Pourthiaea. Considering evidence from morphology and phylogenomic data, we propose a new infrageneric classification for Pourthiaea, consisting of three sections: P. sect. Pourthiaea, P. sect. Amphidoxae sect. nov., and P. sect. Impressivenae sect. nov.