Parsing polyphyletic Pueraria: Delimiting distinct evolutionary lineages through phylogeny

Area of Science:

• Botany
• Evolutionary Biology
• Plant Taxonomy

Background:

• The Pueraria genus (Leguminosae) has been suspected of polyphyly, complicating its taxonomic classification.
• Previous phylogenetic studies were limited by insufficient taxon sampling and evolutionary context.
• The invasive Pueraria montana var. lobata (Kudzu) highlights the need for accurate genus-level understanding.

Purpose of the Study:

• To conduct a comprehensive phylogenetic investigation of the Pueraria genus within the tribe Phaseoleae.
• To clarify the evolutionary relationships and taxonomic status of species within Pueraria.
• To provide a robust evolutionary framework for revising Pueraria taxonomy.

Main Methods:

• Phylogenetic analysis using two chloroplast and one nuclear marker (AS2).
• AS2 marker utilized as a phylogenetic marker for the first time.
• Comprehensive taxon sampling within the tribe Phaseoleae (Leguminosae).

Main Results:

• Confirmed extensive polyphyly within Pueraria, with five distinct lineages identified across the tribe.
• Demonstrated over 25 million years of divergence among these lineages.
• Phylogenetic results strongly supported by multiple genetic markers.

Conclusions:

• The Pueraria genus requires significant taxonomic revision due to its extensive polyphyly.
• The study supports the resurrection of Neustanthus, transfer of a species to Teyleria, and creation of two new genera: Haymondia and Toxicopueraria.
• This research provides a crucial evolutionary context for understanding and resolving taxonomic issues in Pueraria and related legumes.