2026/07/01 by Rushan Yan, Furrukh Mehmood, Liya Guo +6 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Genomics and Phylogenetic Studies #Plant Diversity and Evolution #Plant Taxonomy and Phylogenetics
paper · doi:10.1002/ece3.74010
openalex publication_date 2026/07/01 · openalex created_date 2026/07/12 · openalex updated_date 2026/08/01
ABSTRACT Tribe Hibisceae (Malvaceae) has persistent taxonomic challenges due largely to the extensive polyphyly of Hibiscus L. Recently, Hibiscus caesius was segregated into the monotypic genus Astrohibiscus McLay and R.L. Barrett as Astrohibiscus caesius (Garcke) McLay and R.L. Barrett. Here, we sequenced, de novo assembled, and characterized the first complete plastid genome of A. caesius and conducted phylogenomic analyses to provide a genomic resource for evolutionary, phylogeographic, and conservation studies of this newly recognized genus. The plastid genome is 161,092 bp in length and exhibits the typical quadripartite architecture, comprising a large single‐copy region (89,340 bp), a small single‐copy region (20,486 bp), and a pair of inverted repeats (25,633 bp each). The genome has an overall GC content of 36.94% and encodes 112 unique genes (78 protein‐coding, 30 tRNA, and 4 rRNA genes). Codon usage showed bias toward A/T‐ending codons (RSCU > 1), while leucine was the most abundant amino acid, and cysteine was the least frequent. Simple sequence repeat (SSR) analysis identified a predominance of A/T‐rich mononucleotide repeats, providing candidate molecular markers for population‐genetic studies. Maximum likelihood phylogenetic analysis of 78 shared protein‐coding genes across subfamily Malvoideae yielded a well‐resolved topology with strong bootstrap support. Hibiscus was polyphyletic, consistent with previous studies, while A. caesius formed a distinct lineage outside all major Hibiscus clades, consistent with its recognition as a distinct genus. These findings provide a genomic resource for future evolutionary, phylogeographic, and taxonomic studies within Hibisceae.