Species delimitation in Amana (Liliaceae): transcriptomes battle with evolutionary complexity

Area of Science:

• Botany
• Evolutionary Biology
• Genomics

Background:

• Species delimitation in plants is controversial, with diverse concepts and methods.
• The genus Amana (East Asian tulips) presents challenges due to cryptic species, large genome size, and adaptation to subtropical areas.

Purpose of the Study:

• To clarify phylogenetic relationships and species delimitation within the genus Amana.
• To investigate the evolutionary history, including hybridization and introgression events.
• To propose a new species and discuss the role of genomic data in plant taxonomy.

Main Methods:

• Integration of morphological, ecological, and genetic data.
• Phylogenetic analyses using transcriptomic and plastid DNA.
• Phylonetworks, admixture, and ABBA-BABA analyses to detect hybridization.
• Application of multiple species concepts (morphological, ecological, genetic, evolutionary, phylogenetic).

Main Results:

• Recognition of at least 12 species within the genus Amana.
• Detection of historical hybridization and introgression events.
• Evidence of parallel evolution in morphological traits.
• Proposal of a new species, Amana polymorpha, from China.

Conclusions:

• Genomic data, particularly transcriptomes, significantly enhance the accuracy of species delimitation and taxonomic classification.
• The genus Amana exhibits a complex evolutionary history shaped by hybridization and adaptation.
• Further research is needed to test hypotheses regarding the adaptive evolution of Amana in subtropical regions.