Multilocus coalescent species delimitation to evaluate traditionally defined morphotypes in Hydrangea sect. Asperae...

Area of Science:

• Botany
• Molecular Biology
• Taxonomy

Background:

• Species delimitation in Hydrangea Asperae (H. sect. Asperae) is inconsistent, with varying numbers of species recognized.
• Previous studies indicated molecular variation but lacked sequence-based species delimitation to assess morphology-based boundaries.

Purpose of the Study:

• To employ a multi-locus coalescent-based approach for species delimitation within H. sect. Asperae.
• To identify distinct evolutionary lineages and evaluate conflicts with traditional taxonomy.

Main Methods:

• Utilized a multi-locus coalescent-based species delimitation approach.
• Analyzed four chloroplast and four nuclear molecular markers.

Main Results:

• Recovered eight distinct evolutionary lineages within the focal group.
• Five lineages corresponded to established morphotypes, while three revealed conflicts between molecular and morphological data.
• Identified instances where molecular data suggested a single species comprising multiple morphotypes, and vice versa.

Conclusions:

• Molecular species delimitation provides a new perspective on the H. sect. Asperae species complex.
• Conflicts between molecular and morphological data necessitate further investigation into species boundaries and evolutionary history.
• The findings suggest potential revisions to the taxonomy of H. sect. Asperae.