RESUMO
Recently, the systematic status of Fortunella Swingle and its taxonomy has attracted much attention. Flora of China incorporates Fortunella into Citrus Linn. and treats all species of the traditional Fortunella as one species, namely Citrus japonica (Thunb.) Swingle. Furthermore, F. venosa (Champ. ex Benth.) C. C. Huang and F. hindsii (Champ. ex Benth.) Swingle are currently considered as synonyms of C. japonica. In this paper, morphological, palynological, and phylogenetic analyses were used to systematically explore the taxonomic status of traditional Fortunella. The key morphological features that differed among the Fortunella species were the leaf and the petiole hence could be key in its taxonomic classification of the species. Additionally, pollen morphological analysis based on the pollen size, germination grooves, polar, and equatorial axes also supported the separation of the species. The results of the phylogenetic analysis showed that each of the three species clustered separately, hence strongly supporting the conclusion of independent species. In addition, the phylogenetic analysis showed that the two genera clustered closely together hence our results support the incorporation of Fortunella into Citrus. Based on the above, this article has revised the classification of the traditional Fortunella and determined that this genus has three species, namely; F. venosa, F. hindsii, and F. japonica. F. venosa and F. hindsii are placed in the Citrus as separate species, and their species names still use the previous specific epithet. The revised scientific names of the new combinations of F. venosa and F. hindsii are as follows: Citrus venosa (Champ. ex Benth.) K. M. Liu, X. Z. Cai, and G. W. Hu, comb. nov. and Citrus hindsii (Champ. ex Benth.) K. M. Liu, G. W. Hu, and X. Z. Cai, comb. nov. F. venosa is the original species of Fortunella, F. venosa and F. hindsii are both listed as the second-class key protected wild plants in China. Therefore, the establishment of the taxonomic status of F. venosa and F. hindsii not only deepens our understanding, importance, and the complexity of the systematic classification of Fortunella, but is also significant for global biodiversity conservation, genetic resources for breeding purposes, and population genetics.
RESUMO
Coleanthus subtilis (Tratt.) Seidel (Poaceae) is an ephemeral grass from the monotypic genus Coleanthus Seidl, which grows on wet muddy areas such as fishponds or reservoirs. As a rare species with strict habitat requirements, it is protected at international and national levels. In this study, we sequenced its whole chloroplast genome for the first time using the next-generation sequencing (NGS) technology on the Illumina platform, and performed a comparative and phylogenetic analysis with the related species in Poaceae. The complete chloroplast genome of C. subtilis is 135,915 bp in length, with a quadripartite structure having two 21,529 bp inverted repeat regions (IRs) dividing the entire circular genome into a large single copy region (LSC) of 80,100 bp and a small single copy region (SSC) of 12,757 bp. The overall GC content is 38.3%, while the GC contents in LSC, SSC, and IR regions are 36.3%, 32.4%, and 43.9%, respectively. A total of 129 genes were annotated in the chloroplast genome, including 83 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. The accD gene and the introns of both clpP and rpoC1 genes were missing. In addition, the ycf1, ycf2, ycf15, and ycf68 were pseudogenes. Although the chloroplast genome structure of C. subtilis was found to be conserved and stable in general, 26 SSRs and 13 highly variable loci were detected, these regions have the potential to be developed as important molecular markers for the subfamily Pooideae. Phylogenetic analysis with species in Poaceae indicated that Coleanthus and Phippsia were sister groups, and provided new insights into the relationship between Coleanthus, Zingeria, and Colpodium. This study presents the initial chloroplast genome report of C. subtilis, which provides an essential data reference for further research on its origin.
