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

Abstract

In this comprehensive study, we conducted extensive taxon sampling and performed phylogenomic analyses based on 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 genusPourthiaea. The nrDNA phylogeny ofPourthiaeastrongly supported three major clades, which were consistent with morphology. However, the plastid tree provided an alternative phylogenetic topology, indicating cytonuclear discordance. Frequent hybridizations between and among the species ofPourthiaeacould explain the cytonuclear discordance. Considering the evidence from morphology and phylogenomic data, we propose a new infrageneric classification forPourthiaea, consisting of three sections:P. sect.Pourthiaea,P. sect.AmphidoxaeB.B.Liu, andP. sect.ImpressivenaeB.B.Liu.