Abstract
Ranunculus L., the largest genus of Ranunculaceae, exhibits remarkable ecological diversity, yet genomic resources for this genus remain limited. Here we report the complete chloroplast (cp) genomes of Ranunculus arvensis L. and Ranunculus laetus Wall. ex Hook.f. & Thomson. The R. laetus assembly is the first cp genome reported for this species, whereas the R. arvensis assembly, generated from a Pakistani population, provides an independent accession that complements the recently released GenBank record PV621859 from China. Both genomes were analyzed comparatively against 22 previously published Ranunculus cp genomes. The cp genomes ranged from 154,474 to 158,314 bp in length and displayed a typical quadripartite structure. All analyzed species harbored 112 unique genes, comprising 78 protein‐coding genes, 30 transfer RNA genes, and four ribosomal RNA genes. The cp genomes were highly conserved in terms of gene order, guanine–cytosine content, codon usage, amino acid composition, and simple sequence repeats. Phylogeny‐aware selection analysis models (BUSTED, MEME, FUBAR) revealed that, despite overall purifying selection at the gene level, codon‐based FUBAR detected pervasive positive selection across ~34.6% of plastid genes; matK and ycf1 emerged as the most prominent hotspots for both episodic and pervasive adaptation. Nucleotide diversity analyses revealed several highly variable regions, notably rpl32–ndhF, ycf1, and ndhF. Phylogenetic analyses based on complete cp genome sequences and complementary single‐gene trees resolved two major clades corresponding to biogeographic patterns: Clade I comprised predominantly Eurasian and East Asian taxa, whereas Clade II comprised a transcontinental assemblage of East Asian, North American, and Himalayan species. The R. laetus and R. arvensis were grouped in Clade II. Overall, these results elucidate the conserved genomic architecture, evolutionary dynamics, and phylogenetic relationships of Ranunculus cp genomes and provide valuable genomic resources for future studies on phylogeny, taxonomy, DNA barcoding, and population genetics within Ranunculaceae.