Phylogenetic systematics of genus Holigarna Buch.-Ham. ex Roxb. An endemic tree plant species of Western Ghats

Abstract

The genus Holigarna Buch.-Ham. ex Roxb. (Family: Anacardiaceae) contributes significantly to the Western Ghats forest flora, with seven species, five indigenous to the area. The genus is classified as taxonomically challenging owing to its diverse and complex floral features. In this context, we took the molecular phylogenetics of the genus Holigarna as the main objective of this study. Molecular tools are becoming more widely accepted as a useful tool in phylogenetic investigations of taxonomically challenging taxa. Molecular markers can depict the genetic link across plant groupings, and DNA-based molecular taxonomic techniques provide an accurate and quick way to differentiate specimens based on interspecies variance. The genetic profiles of five Holigarna species, Holigarna arnottiana Hook. f., Holigarna beddomei Hook. f., Holigarna ferruginea Marchand, Holigarna grahamii Wight, and Holigarna nigra Bourd. Phylogenetic results confirmed that the genus Holigarna is a monophyletic group with best-supporting bootstrap values and unresolved relationships and a polytomy within the group suggest rapid evolution or limited resolution from the current markers. The unresolved connections and polytomy within the group indicate either fast evolution or insufficient resolution from the existing markers. These results provide a foundation for further taxonomic and evolutionary research on Holigarna.