Syzygium buxifolium. Hook. Et Arn.1833 is a member of the Myrtaceae family. This species is used in traditional Chinese medicines. It possesses numerous synonyms, reflecting the ambiguity in its taxonomy. The chloroplast genome has been widely used for species identification and phylogenetic analysis. Regrettably, there is a lack of information regarding the chloroplast genome of S. buxifolium. Here, we intend to obtain the chloroplast genome of S. buxifolium to resolve its classification problems. In particular, we utilized Illumina sequencing technology to sequence, GetOrganelle to assemble, and CPGAVAS2 to characterize the chloroplast genome of S. buxifolium. The chloroplast genome of S. buxifolium had a length of 158,581 bp and consisted of 111 unique genes, comprising 78 protein-coding genes, 29 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. In addition, we identified 86 Simple Sequence Repeats, 345 tandem repetitive sequences, and 34 dispersed repetitive sequences using modules implemented in CPGAVAS2. Lastly, we carried out phylogenetic analysis using Phylosuite. The results indicated a close relationship between S. buxifolium and S. grijsii. This study offers novel genetic data for the molecular identification and subsequent phylogenetic analysis of the Syzygium genus.

Background Inula britannica is an important medicinal plant of Asteraceae. Its dry capitulum has been used as a traditional Chinese herbal medicine, which had the functions of treating edemas, reduction in nausea, and preventing vomiting. There have not been many chloroplast genome studies. Methods and results we de novo assembly of the complete chloroplast genome of I. britannica. The genome was characterized and compared with the other five Inula species. The chloroplast genome of I. Britannica was 150,774 bp long. It showed a typical quadripartite structure, containing a large single-copy region, a small single-copy region, and a pair of inverted repeat regions, which were 82,451 bp, 18,423 bp, and 24,950 bp long, respectively. It encoded 109 unique genes, including 79 protein-coding genes, four rRNA genes, and 26 tRNA genes. Forty-nine long repetitive sequences and 69 simple sequence repeats were identified in the I. britannica chloroplast genome. We detected 14 hypervariable regions and identified six pairs of genus-specific DNA markers, which could differentiate congeneric species. Phylogenetic analysis showed that I. britannica was closely related to I. janopinca and I. linariifolia. Ancestral character state reconstruction indicated transitions from long spur to other petal types in Inula. Results from divergence time analysis showed that Inula diversified in the late Pliocene (~ 3.245 Mya). Conclusion In this study, we sequenced and assembled the chloroplast genome of I. Britannica. Phylogenomic analysis has identified species closely related to I. britannica, which will help determine its evolutionary relationships and taxonomic status.

Pterospermum heterophyllum Hance (1868), a member of the Malvaceae family, is widely distributed across southwestern and southeastern China and has been traditionally used in folk medicine to treat rheumatoid arthritis and inflammation-related diseases. The circular genome is 162,857 bp long and exhibits a typical quadripartite structure, consisting of an LSC (91,356 bp), SSC (20,567 bp), and two IRs (25,467 bp each). A total of 130 genes were annotated. The multiple sequence alignment revealed that infA gene contained a large 3′ deletion truncating the coding sequence. Phylogenetic analysis revealed that P. heterophyllum is closely related to P. kingtungense and P. truncatolobatum.