A Phylogenetic and Morphological Evolution Study of Ribes L. in China Using RAD-Seq

Area of Science:

• Botany
• Plant Taxonomy
• Molecular Phylogenetics

Background:

• The genus Ribes L. (Grossulariaceae family) is taxonomically challenging due to species diversity, wide distribution, and morphological variation.
• Accurate classification of Ribes L. is crucial for understanding its significant edible, medicinal, ornamental, and landscaping values.

Purpose of the Study:

• To elucidate the phylogenetic relationships among Ribes L. taxa in China.
• To provide a molecular basis for a revised global classification of the genus Ribes L.

Main Methods:

• Phylogenetic analysis of 52 Ribes L. samples from 30 species using restriction site-associated DNA sequencing (RADseq) and single nucleotide polymorphisms (SNPs).
• Ancestral state reconstruction of two key taxonomic characters based on the molecular phylogeny.

Main Results:

• The 52 samples clustered into six distinct phylogenetic branches, corresponding to six subgenera, challenging existing morphological classifications.
• Molecular data supported the separation of subg. Coreosma from subg. Ribesia and subg. Hemibotrya from subg. Berisia.
• The recognition of subg. Grossularia as an independent subgenus was validated through molecular phylogeny and ancestral trait reconstruction.

Conclusions:

• The study provides a robust molecular phylogeny for Chinese Ribes L. taxa, resolving taxonomic controversies.
• Gene flow among Ribes L. populations was detected, offering insights into their evolutionary history.
• The findings support a revised classification of Ribes L. at the subgeneric level, with implications for global taxonomy.