Caylusea hexagyna and Ochradenus baccatus are two species in the Resedaceae family. In this study, we analysed the complete plastid genomes of these two species using high-throughput sequencing technology and compared their genomic data. The length of the plastid genome of C. hexagyna was 154,390 bp while that of O. baccatus was 153,380 bp. The lengths of the inverted repeats (IR) regions were 26,526 bp and 26,558 bp, those of the large single copy (LSC) regions were 83,870 bp and 83,023 bp; and those of the small single copy (SSC) regions were 17,468 bp and 17,241 bp in C. hexagyna and O. baccatus, respectively. Both genomes consisted of 113 genes: 79 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Repeat analysis showed that the plastid genome included all types of repeats, with more frequent occurrences of palindromic sequences. Comparative studies of SSR markers showed that there were 256 markers in C. hexagyna and 255 in O. baccatus; the majority of the SSRs in these plastid genomes were mononucleotide repeats (A/T). All the clusters in the phylogenetic tree had high support. This study reported the first complete plastid genomes of the genera Caylusea and Ochradenus and the first for the Resedaceae family.

Cordiaceae is a family comprising more than 400 species in the order Boraginales. The classification of this family has undergone changes over time, transitioning between family and subfamily status. In the present study, the complete chloroplast (cp) genomes of Cordia monoica and Cordia sinensis were sequenced, and their cp genomes were then characterized, analyzed, and compared to those of closely related taxa. The lengths of the cp genomes of C. monoica and C. sinensis were 151,813 bp and 152,050 bp, respectively. Both genomes consisted of 114 genes, divided into 4 ribosomal RNA genes, 30 transfer RNA genes, and 80 protein-coding genes. We observed a unique gene inversion in the trnM-rbcL region of both Cordia species. The long repeats analysis revealed that both species’ chloroplast genomes contained forward and palindromic repeats. The simple sequence repeats (SSRs) analysis detected 155 microsatellites in each genome, with the majority being mononucleotide repeats (A/T). Phylogenetic analysis based on maximum likelihood and Bayesian analyses confirmed two major clades in the order Boraginales: clade I comprised Boraginaceae, while clade II included Cordiaceae, Ehretiaceae, and Heliotropiaceae. This study expands our knowledge of the evolutionary relationships across the order Boraginales and offers useful genetic resources.

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.

Ehretiaceae is a family in the order Boraginales. It contains more than 150 species. The Ehretiaceae classification has remained elusive and changed over time from subfamily to family, or vice versa. In this paper, we sequenced, characterized, and analyzed the complete chloroplast (cp) genomes of Ehretia cymosa and Ehretia obtusifolia, and their cp genomes were compared to those of related species. The length of the chloroplast genomes of E. cymosa was 156,328 bp, whereas that of E. obtusifolia was 155,961 bp. Each genome contained 114 genes, including 80 protein-coding genes, 4 rRNA genes, and 30 tRNA genes. Repeat analysis revealed that complement, forward, palindromic, and reverse repeats were present in the chloroplast genomes of both species. Simple sequence repeat analysis showed that the chloroplast genomes of E. cymosa and E. obtusifolia comprise 141 and 139 microsatellites, respectively. Phylogenetic analysis based on Bayesian and maximum likelihood analyses divided the order Boraginales into two well-supported clades. The first clade includes a single family (Boraginaceae), and the second clade includes three families (Ehretiaceae, Cordiaceae, and Heliotropiaceae). This study provides valuable genomic resources and insights into the evolutionary relationships within Boraginales.