RESUMEN
Establishing how lineages with similar traits are phylogenetically related remains critical for understanding the origin of biodiversity on Earth. Floral traits in plants are widely used to explore phylogenetic relationships and to delineate taxonomic groups. The subtribe Swertiinae (Gentianaceae) comprises more than 350 species with high floral diversity ranging from rotate to tubular corollas and possessing diverse nectaries. Here we performed phylogenetic analysis of 60 species from all 15 genera of the subtribe Swertiinae sensu Ho and Liu, representing the range of floral diversity, using data from the nuclear and plastid genomes. Extensive topological conflicts were present between the nuclear and plastome trees. Three of the 15 genera represented by multiple species are polyphyletic in both trees. Key floral traits including corolla type, absence or presence of lobe scales, nectary type, nectary position, and stigma type are randomly distributed in the nuclear and plastome trees without phylogenetic correlation. We also revealed the likely ancient hybrid origin of one large clade comprising 10 genera with diverse floral traits. These results highlight the complex evolutionary history of this subtribe. The phylogenies constructed here provide a basic framework for further exploring the ecological and genetic mechanisms underlying both species diversification and floral diversity.
Asunto(s)
Gentianaceae , Filogenia , Evolución Biológica , Biodiversidad , Plastidios/genéticaRESUMEN
Pterygocalyx volubilis Maxim. (Gentianaceae) is a traditional Chinese medicine, and its whole grass is used in the treatment of pulmonary tuberculosis and other conditions. Here, the complete chloroplast genome sequence of P. volubilis was reported based on the Illumina HiSeq Platform. The chloroplast genome genome is 154,365 bp in length, containing a pair of inverted repeated (IR) regions (25,928 bp) that are separated by a large single copy (LSC) region of 84,033 bp, and a small single copy (SSC) region of 18,476 bp. Moreover, a total of 130 functional genes were annotated, including 85 protein-coding genes, 37 tRNA genes, and eight rRNA genes. In the maximum-likelihood (ML) phylogenetic tree, Pterygocalyx clustered with the genus Swertia. This sequenced chloroplast genome of P. volubilis supports that Pterygocalyx belongs to subtribe Swertiinae.
RESUMEN
Gentianella macrosperma Ma ex H.F. Cao, J.D. Ya & Q.R. Zhang, a new species of Gentianaceae from Xinjiang, Northwest China is described and illustrated. This new species is unique in having equal length of corolla lobe and corolla tube, nectaries located at the throat of the corolla tube and large seeds up to 1.6 mm in diameter. In addition, an updated identification key to the Chinese species of Gentianella is provided.