Mallotus peltatus is a tropical plant of the Euphorbiaceae family, which could be used as a beverage and medicine in Hainan, China. Here, we report and characterize the complete plastome of M. peltatus. The complete plastome is 163,304 bp in length and contains a typical structure and gene content of angiosperm plastome, including two inverted repeat (IR) regions of 27,112 bp, a large single-copy (LSC) region of 89,886 bp and a small single-copy (SSC) region of 18,840 bp. The plastome contains 131 genes, consisting of 78 unique protein-coding genes, 30 unique tRNA gene, four unique rRNA genes (5S rRNA, 4.5S rRNA, 23S rRNA and 16S rRNA), and eight pseudogenes. The overall A/T content in the plastome of M. peltatus is 64.02%. The complete plastome sequence of M. peltatus will provide a useful resource for the conservation genetics of this species as well as for phylogenetic studies in Euphorbiaceae.

Understanding biological diversity and the mechanisms of the Sino-Japanese disjunctions are major challenges in eastern Asia biogeography. The Sino-Japanese flora has been broadly studied as an ideal model for plant phylogeography. Diabelia Landrein (Caprifoliaceae) is an East Asian genus, with a disjunctive distribution across the Sino-Japanese region. However, relationships within Diabelia remain elusive. In this study, we reconstructed the phylogeny of Diabelia and inferred historical biogeography and evolutionary patterns based on nuclear and plastid sequences from target enrichment and genome skimming approaches, respectively. We found that the main clades within Diabelia were discordant between nuclear and plastid trees. Both nuclear and plastid phylogenetic analyses supported five main clades: Diabelia serrata (Siebold & Zucc.) Landrein, Diabelia tetrasepala (Koidz.) Landrein, Diabelia sanguinea (Makino) Landrein, Diabelia stenophylla (Honda) Landrein, and Diabelia spathulata (Siebold & Zucc.) Landrein. Species network analyses revealed that Diabelia tetrasepala is likely the result of a hybridization event. Divergence time estimation and ancestral area reconstructions showed that Diabelia originated in Japan during the early Miocene, with subsequent vicariance and dispersal events between Japan and Korea, and between Japan and China. Overall, our results support the division of Diabelia into five main clades and the recognition of five species in the genus. This research provides new insights into the species delimitation and speciation processes of taxonomically complex lineages such as Diabelia.

Disjunctive distribution patterns and drivers of the Sino-Japanese flora in East Asia have attracted much attention in the past decades, which is also served as an important glacial sanctuary during the quaternary glacial period. However, few studies have focused on the phylogeography, diversification and evolution of morphological character at the genus level with both nuclear and plastid data. Diabelia (Caprifoliaceae) is an East Asian genus, with a disjunctive distribution across China, Japan and Korea, serving as an ideal group to explore the mechanism of East Asian flora speciation and diversification. However, the phylogenetic relationships among Diabelia remain elusive and species delimitation within the genus (three species or four species) are still controversial. In this study, we reconstructed the phylogenetic relationships among Diabelia based on nuclear and cpDNA by using target enrichment and genome skimming approaches, respectively. We found that the main clades within Diabelia were discordant between nuclear and plastid genome trees. Both nuclear and plastid phylogenetic analyses supported five main clades: D. serrata, D. tetrasepala, D. spathulata var. sanguinea, D. spathulata var. stenophylla and D. spathulata var. spathulata. Diabelia tetrasepala was inferred to be the result of a hybridization event from the species network analyses. The result of divergence time estimation and ancestral area reconstruction showed that Diabelia originated in Japan during the early Miocene, with subsequent gene flow between China, Japan and Korea. Overall, our results support the division of Diabelia into five main clades and this research provides new insights for the speciation process and taxonomy within Diabelia.

Artocarpus altilis (Parkinson ex F.A. Zorn) Fosberg is native to the Pacific Islands, India, and the Philippines. It is also cultivated in Taiwan and Hainan. The complete plastome of the species was assembled and annotated in this study. The circular genome was 160,184 bp in size, presenting a typical quadripartite structure including two inverted repeats (IRs) of 25,734 bp, a large single-copy (LSC) of 88,791 bp, and a small single-copy (SSC) of 19,925 bp. The genome contained 132 genes, including 87 protein-coding genes, 37 tRNA genes, and eight rRNA genes. The total G/C content of complete plastome was 36.0%, with the corresponding values of the LSC, SSC, and IR being 33.7%, 28.8%, and 42.7%, respectively. The complete plastome sequence of A. altilis (Parkinson ex F.A. Zorn) Fosberg will make contributions to the conservation genetics of this species as well as to phylogenetic studies of Moraceae.

Diospyros nigra (J.F.Gmel.) M.R.Almeida is a rare tree in the family Ebenaceae. The species is native to South America, while having been introduced to Florida and Texas (USA), India, Java and Madagascar. Additionally, this species is distributed in Guangdong Province and the southwest portion of Hainan Province, China. Here, we report and characterize the complete plastome of a cultivar of D. nigra. The length of the complete plastome is 157,168 bp, including 131 genes consisting of 84 protein-coding genes, 37 tRNA genes and 8 rRNA genes. The plastome has the typical structure and gene content of angiosperms, including two inverted repeat (IR) regions of 26,095 bp, a large single copy (LSC) region of 86,610 bp and a small single-copy (SSC) region of 18,386 bp. The total G/C content of the plastome in D. nigra is 37.4%. The complete plastome sequence of D. nigra will make contributions to the conservation genetics of the species, as well as to phylogenetic studies in Ebenaceae.