The GRF (Growth-Regulating Factor) gene family has indispensable regulatory functions in the morphological and physiological development of plants. Nonetheless, comprehensive investigations of GRF gene family members and their functional roles in Cymbidium goeringii, Cymbidium ensifolium, and Cymbidium sinense are still lacking. Therefore, the GRF gene family members in three Cymbidium species were systematically identified, and their expression profiles and potential biological functions were comprehensively evaluated in the study. The results provided evidence that eleven, eleven, and nine GRF genes were identified in C. goeringii, C. ensifolium, and C. sinense, respectively. These genes encode proteins considered as 153–584 amino acids and have been postulated to be located in the cell nucleus. The promoter contains cis-acting elements associated with hormone response regulation, tissue-specific expression, modulation of organismal growth and development, and environmental signal response. The analyses of gene architecture and motif composition demonstrated that introns and motifs within each evolutionary branch are highly similar, whereas significant differences exist between evolutionary branches. The results of chromosome localization and collinearity analysis showed that only a pair of segmental duplication genes was identified in C. goeringii. Moreover, transcriptome data and qRT-PCR results indicated that GRF genes are involved in various organs of C. goeringii. In conclusion, these findings may establish a foundation for theoretical inquiry into the future functional analysis of GRF genes in orchids.

Blastus Lour. is a taxonomically complex genus of Sonerileae (Melastomataceae), with unresolved infrageneric relationships and controversial boundaries among several species and varieties. In this study, we integrated morphological evidence with a broadly sampled internal transcribed spacer (ITS) dataset, an expanded nuclear ribosomal DNA (nrDNA) dataset, plastome data, and genomic single-nucleotide polymorphism (SNP) data to evaluate the phylogenetic relationships and classification within Blastus. The broadly sampled ITS and expanded nrDNA analyses supported the monophyly of the sampled Blastus accessions but provided limited resolution of relationships among closely related taxa. The plastome analysis did not recover the sampled Blastus accessions as monophyletic and revealed marked cytonuclear phylogenetic incongruence. The genomic SNP analysis strongly supported the monophyly of the sampled Blastus accessions and recovered the sampled members of the terminal inflorescence group as a monophyletic clade. However, the sampled members of the traditional axillary inflorescence group were not monophyletic because Blastus borneensis was recovered as sister to the terminal inflorescence clade. Within the terminal inflorescence clade, the sampled members of the B. pauciflorus and B. cavaleriei groups formed two strongly supported sister lineages. Morphological comparisons showed that inflorescence position and architecture, the distribution of yellow glands on the abaxial leaf surfaces, and calyx lobe morphology generally corresponded to the principal lineages recovered in the SNP tree, whereas indumentum characters varied considerably among individuals and populations. We therefore recommend retaining the axillary and terminal inflorescence groups as descriptive morphological categories and treating the B. pauciflorus and B. cavaleriei groups as two informal working subdivisions within the terminal inflorescence group. The broad circumscription of B. pauciflorus adopted in the Flora of China requires reassessment, whereas the boundaries of B. longiflorus var. apricus and B. dunnianus require broader population sampling before formal taxonomic changes are proposed.