Plastome Characterization, Phylogenetic Relationships, and Regional Conservation Status of Ficus populifolia Vahl. (Moraceae), a Peripherally Isolated Plant Population in the Arabian Peninsula

The Ficus populifolia Vahl. in the Arabian Peninsula is threatened, peripheral, and geographically isolated from its main population in Africa. Here, the entire plastome of F. populifolia from the Arabian Peninsula was sequenced and analyzed to provide a baseline genetic resource for future research. The F. populifolia plastome has a classic quadripartite structure with a size of 160,610 bp, the large and small single copies of 88,729 and 20,097 bp, respectively, and each pair of inverted repeats are 25,892 bp. The genome includes 113 unique genes, 79 protein-coding genes, 30 tRNAs, and 4 rRNAs. The results reveal a total of 49 long repeats, including (30) palindromic, (14) forward, and (5) reverse repeats. Similarly, a total of 186 simple sequence repeats were identified, 83.8% of which were mononucleotides. The genomic comparison with four Ficus species indicated that the plastome of F. populifolia was highly conserved, with some hypervariable noncoding regions. The phylogenomic analysis of 28 species of Ficus, based on 78 coding genes, revealed that F. populifolia is closely related to the African species F. lyrata. The genomic data generated in this study provide valuable resources for future investigations on the population genetics, authentication, and genetic conservation of the wild Arabian population of F. populifolia.