Non-monophyly of Primula subgenera Auganthus and Carolinella (Primlaceae) as confirmed by the nuclear DNA sequence variation

Abstract

An earlier molecular phylogenetic analysis using cpDNA sequence data revealed the non-monophyly of Primula subgenera Auganthus and Carolinella, and the evolutionary implication of the infrageneric division of these two groups remains uncertain. In the present study, 130 new sequences were newly analyzed, with the combination of plastid genes and nrDNA ITS regions through maximum parsimony and Bayesian inference analyses. It confirms that neither subgenus Auganthus nor subgenus Carolinella is monophyletic in its current circumscription. The calyptrate capsule, a diagnostic character for subgenus Carolinella, may have evolved multiple times in Primula. Subgenus Auganthus would be a natural group only with inclusion of subgenus Carolinella and exclusion of P. aromatica. The positions of some infrageneric groups are clarified, but challenges remain regarding relevant morphological characters for sectional delimitations within subgenus Auganthus.