RESUMO
Melastomataceae has abundant morphological diversity with high economic and ornamental merit in Myrtales. The phylogenetic position of Myrtales is still contested. Here, we report the chromosome-level genome assembly of Melastoma dodecandrum in Melastomataceae. The assembled genome size is 299.81 Mb with a contig N50 value of 3.00 Mb. Genome evolution analysis indicated that M. dodecandrum, Eucalyptus grandis, and Punica granatum were clustered into a clade of Myrtales and formed a sister group with the ancestor of fabids and malvids. We found that M. dodecandrum experienced four whole-genome polyploidization events: the ancient event was shared with most eudicots, one event was shared with Myrtales, and the other two events were unique to M. dodecandrum. Moreover, we identified MADS-box genes and found that the AP1-like genes expanded, and AP3-like genes might have undergone subfunctionalization. The SUAR63-like genes and AG-like genes showed different expression patterns in stamens, which may be associated with heteranthery. In addition, we found that LAZY1-like genes were involved in the negative regulation of stem branching development, which may be related to its creeping features. Our study sheds new light on the evolution of Melastomataceae and Myrtales, which provides a comprehensive genetic resource for future research.
Assuntos
Melastomataceae , Myrtales , Evolução Molecular , Genoma de Planta/genética , FilogeniaRESUMO
Blastus pauciflorus, a shrub endemic to Hong Kong and Guangdong, south China, growing on low-altitude hillsides, under the forest. The species is controversial in classification. Herein, we report the complete chloroplast genome sequence assembled from Illumina pair-end sequencing data, with aims to resolve its relationship with the related species. The complete chloroplast genome was 155,983 bp in length, includes two inverted repeat regions (IRs) of 26,716 bp each, which were separated by a large single copy region (LSC) 86,101 bp and a small single copy region (SSC) 16,450 bp. The chloroplast genome contained 129 genes, including 82 protein-coding genes, 2 pseudogenes, 37 tRNA genes and 8 rRNA genes. The overall GC content in the chloroplast genome of B. pauciflorus was 37.0%. Phylogenetic analysis showed that B. pauciflorus is closed to B. cochinchinensis.