Eriobotrya (Rosaceae) is an economically important genus with around 30 species. It is widely distributed in tropical and warm temperate regions of Asia, with most of its species in China, Myanmar, and Vietnam. However, Eriobotrya is often confused with the smaller genus Rhaphiolepis, and the phylogenetic relationships between the two genera are controversial. Here we present phylogenetic analyses of 38 newly generated Eriobotrya and Rhaphiolepis nrDNA together with 16 sequences of nrDNA and 28 sequences of ITS obtained from GenBank, representing 28 species of Eriobotrya and 12 species of Rhaphiolepis, in order to reconstruct highly supported relationships for the two genera. Contrary to previous research based on limited sampling, our results highlight the monophyly of Eriobotrya as well as Rhaphiolepis. The topology recovered here is consistent with key morphological synapomorphies such as the persistent sepals in Eriobotrya. Our findings show that increased sampling of taxa can provide a more robust phylogeny through reducing phylogenetic error and increasing overall phylogenetic accuracy.

Rosa lucieae Franch. & Rochebr. ex Crép. is one of the famous wild ancestors of cultivated roses and plays a very important role in horticultural research, but there is still a lack of research on the R. lucieae chloroplast genome. In this study, we used the Illumina MiSeq sequencing platform for sequencing, assembly and annotation to obtain the sequence information for the R. lucieae chloroplast genome and compared genomics, selection 1 stress analysis, and phylogenetic analysis with 12 other chloroplast genomes of Rosa. The R. lucieae cpDNA sequence has a total length of 156,504 bp and 130 genes are annotated. The length of all 13 studied chloroplast genomes is 156,333~157,385 bp. Their gene content, gene sequence, GC content and IR boundary structure were highly similar. Five kinds of large repeats were detected that numbered 100~116, and SSR sequences ranged from 78 to 90 bp. Four highly differentiated regions were identified, which can be used as potential genetic markers for Rosa. Selection stress analysis showed that there was significant positive selection among the 18 genes. The phylogenetic analysis of R. lucieae and R. cymose, R. maximowicziana, R. multiflora, and R. pricei showed the closest relationship. Overall, our results provide a more comprehensive understanding of the systematic genomics and comparative genomics of Rosa.

Rosa lucieae is one of the famous wild ancestors of cultivated roses and plays a very important role in horticultural research, but there is still a lack of research on the R. lucieae chloroplast genome. In this study, we used the Illumina MiSeq platform for sequencing, assembly, and annotation to obtain the R. lucieae chloroplast genome sequencing information and compared genomics, selection stress analysis, and phylogenetic analysis with 12 other chloroplast genomes of Rosa. The R. lucieae cpDNA sequence has a total length of 156,504 bp, and 130 genes are annotated. The length of all 13 studied chloroplast genomes is 156,333~157,385 bp. Their gene content, gene sequence, GC content, and IR boundary structure were highly similar. Five kinds of large repeats were detected that numbered 100~116, and SSR sequences ranged from 78 to 90 bp. Four highly differentiated regions were identified, which can be used as potential genetic markers for Rosa. Selection stress analysis showed that there was significant positive selection among the 18 genes. The phylogenetic analysis of R. lucieae and R. cymose, R. maximowicziana, R. multiflora, and R. pricei showed the closest relationship. Overall, our results provide a more comprehensive understanding of the systematic genomics and comparative genomics of Rosa.

Mangifera plants are tropical fruits that have high economic value and scientific utility. However, the chloroplast genome characteristics and phylogenetic relationships among Mangifera species remain unclear. In this work, we reconstructed maximum likelihood (ML) and Bayesian inference (BI) phylogenetic trees using 11 newly sequenced chloroplast genomes as well as six existing genomes obtained from the National Center for Biotechnology Information (NCBI) database. The chloroplast genomes all had a typical quadripartite structure, with lengths ranging from 157,368 to 158,942 bp. The GC-content in the genomes ranged from 37.8% to 37.9%. We found conserved boundaries comprised of two inverted repeats (IRs), large single-copy (LSC) regions, and small single-copy (SSC) regions. Nucleotide polymorphism analysis revealed three hypervariable regions (ycf4-cemA, rps18-rpl20, and rpl32-ndhF) in the LSC and SSC regions, which could potentially be used as DNA barcodes for Mangifera species. According to our phylogenetic analysis, Mangifera plants were clustered into three clades. Among them, all five samples of M. indica formed a monophyletic group in Clade Ⅰ. Clade Ⅱ included seven Mangifera species and could be further divided into five subclades with 100% branch support values. Clade Ⅲ included two M. persiciforma samples that formed a monophyletic group. Taken together, these results provide a theoretical basis for species determination, in addition to shedding light on the evolution of Mangifera.

Pourthiaea is of great ornamental value because it produces white flowers in spring and summer, red fruit in autumn, and their fruit does not fall in winter. In order to explore the genetic structure and evolutionary characteristics of the chloroplast genome of Pourthiaea, comparative genomics analysis and phylogenetic analysis were conducted using ten published chloroplast genomes of Pourthiaea from the NCBI database. The results showed that the chloroplast genomes of the ten species of Pourthiaea showed typical circular tetrad structures, and the genome sizes were all within the range of 160,159–160,401 bp, in which the large single copy was 88,047–88,359 bp, the small single copy was 19,234–19,338 bp, and the lengths of a pair of inverted repeats were 26,341–26,401 bp. The GC contents ranged from 36.5% to 36.6%. A total of 1017 SSR loci were identified from the chloroplast genomes of the ten species of Pourthiaea, including six types of nucleotide repeats. The gene types and gene distribution of the IR boundary regions of the chloroplast genomes of different species of Pourthiaea were highly conservative, with little variation. Through the sequence alignment of chloroplast genomes, it was found that the chloroplast genomes of the ten species of Pourthiaea were generally highly conservative. The variation mainly occurred in the spacer regions of adjacent genes. Through nucleic acid diversity analysis, three hypervariable regions were screened at Pi > 0.006, namely trnQ(UUC)-psbk-psbl, accD-psal, and ndhF-rpl32-trnL (UAG). Phylogenetic analysis showed that the ten species of the genus Pourthiaea were clustered in the same branch and formed sister groups with the genus Stranvaesia, and that the support rate for the monophyly of the genus Pourthiaea was high. This study can serve as a reference for the breeding, genetic evolution, and phylogeny of Pourthiaea.