The complete plastid genome of Ferula communis (Apiaceae): structural features and phylogenetic insights

Ferula communis, native to the Mediterranean, is a highly polymorphic species with ambiguous morphological and chemical boundaries. Molecular evidence has revealed close relationships with morphologically similar species from Africa and the Mediterranean islands, supporting their inclusion within the subgenus Ferula. Traditionally valued for its aromatic oleo-gum-resins, F. communis shares a longstanding historical significance with related taxa. To provide a genomic foundation for understanding its evolutionary relationships and characteristics, we assembled the plastid genome of F. communis using GetOrganelle and NOVOPlasty from Illumina whole genome sequence reads. The resulting 166,696 bp genome exhibits the typical quadripartite structure of angiosperm plastomes (LSC: 85,349 bp, SSC: 17,685 bp, IRs: 31,831 bp each) and contains 133 unique functional genes (88 protein-coding, 37 tRNAs, 8 rRNAs). Comparative genomic analysis within Ferula showed high conservation, highlighting minor variation in the IRb/SSC boundary and identifying seven highly variable intergenic spacer regions. Beyond broad genomic comparisons, we also identified 217 simple sequence repeats (SSRs), predominantly in the LSC region, and found evidence of strong positive selection in five protein-coding genes (ccsA, ndhD, ndhF, petD, and rpl32) using BEB and LRT tests. The resulting phylogenetic analysis strongly supports the placement of F. communis immediately after the subgenus Sinoferula, consistent with recent infrageneric classifications based on combined nuclear and plastid markers.