Comparative chloroplast genomics of Gnaphalieae (Asteraceae)

A comparative chloroplast-genome study reported a dataset covering 61 Gnaphalieae species from 26 genera, with the de novo assembly of 25 species in 13 genera and the first reported chloroplast genomes for seven genera. The research was presented as the most comprehensive chloroplast genomic analysis of the tribe to date. Its scope included both subtribes and all major informal clades of Gnaphalieae, a group that the abstract says comprises approximately 2,100 species worldwide.

The researchers combined the 25 newly assembled chloroplast genomes with 36 previously reported genomes retrieved from the NCBI database. Across the resulting dataset, genome sizes ranged from 151,073 to 154,259 base pairs. The genomes retained a typical quadripartite structure and showed high conservation in gene content, with 112 unique genes, as well as in gene organization, guanine–cytosine content and intron composition. Inverted-repeat boundaries, amino-acid composition and codon usage were also highly similar among species, while simple sequence repeats showed a moderate degree of variation.

Maximum-likelihood phylogenetic analyses supported the division of Gnaphalieae into the two subtribes Relhaniinae and Gnaphaliinae and placed the Relhania clade as the earliest-diverging lineage in the chloroplast tree. The analysis did not recover several large genera—including Gnaphalium, Anaphalis, Pseudognaphalium and Helichrysum—as monophyletic. The backbone of the Filago–Leontopodium–Antennaria–Gamochaeta, or FLAG, clade received only weak support, contrasting with earlier topologies based on nuclear ITS and ETS data. The authors characterized this difference between chloroplast and nuclear evidence as cytonuclear discordance and said both sources of data would be needed for accurate taxonomic inference in rapidly radiating lineages.

The findings and limitations summarized here are based on the supplied abstract of an accepted research article that the publisher states remains subject to further edits. The chloroplast dataset covers 61 species rather than the approximately 2,100 species estimated to occur in the tribe, and its phylogenetic signal was not uniform across the group. The reported non-monophyly and weak support should therefore be interpreted as results of this chloroplast-based analysis rather than as a definitive revision of Gnaphalieae taxonomy.

Subject of Research: Comparative chloroplast genomics and phylogenetic relationships in the plant tribe Gnaphalieae

Article Title: Comparative chloroplast genomics of Gnaphalieae (Asteraceae)

Article References: Abdullah, & Heidari, P. (2026). Comparative chloroplast genomics of Gnaphalieae (Asteraceae). BMC Plant Biology. https://doi.org/10.1186/s12870-026-10004-y

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10004-y

Keywords: Gnaphalieae, Asteraceae, chloroplast genomes, comparative genomics, phylogenetics, maximum likelihood, cytonuclear discordance, taxonomy, Comparative, chloroplast, genomics, scientific research