Reticulate evolution in the Pteris fauriei group (Pteridaceae)

Area of Science:

• Botany
• Evolutionary Biology
• Genetics

Background:

• The Pteris fauriei group (Pteridaceae) is a diverse fern lineage in Eastern Asia, comprising 18 species with complex and variable morphology.
• Previous studies indicate morphological similarities among species, leading to taxonomic difficulties.

Purpose of the Study:

• To investigate the evolutionary history and phylogenetic relationships within the Pteris fauriei group.
• To understand the role of hybridization and polyploidy in the diversification of this fern group.

Main Methods:

• Phylogenetic analyses using chloroplast and nuclear DNA markers.
• Ploidy level determination through flow cytometry.
• Morphological and ecological data collection from over 300 specimens.

Main Results:

• Complex reticulate evolution was revealed, involving seven parental taxa and 58 distinct hybrid taxa.
• Hybrids exhibited broader geographic ranges and more numerous populations compared to their parental species.
• Divergent hybrid phenotypes were observed, linked to novel genetic combinations, niche differentiation, and common apogamy.

Conclusions:

• Frequent hybridization is a key driver of genetic diversity and speciation in the Pteris fauriei group.
• Hybridization, niche novelty, and apogamy contribute to the evolutionary success and sustainability of the group.
• The high number of hybrids presents significant taxonomic challenges within the Pteris fauriei complex.