Recently, with the support of the National Natural Science Foundation and the Guangdong Province Woody Plant Germplasm Resources Survey, scientists from China and abroad have conducted research on the systematic relationships of all known species of the genus Dendrobium, species of the related genus Pedilonum, and representative species of other subfamilies within the Leguminosae family. This research combined morphological studies with plastid phylogenomics technology and was published in the journal "Taxon."
The Leguminosae family is the third largest family of angiosperms in terms of species diversity, following only the Asteraceae and Orchidaceae families. Many species in this family hold significant economic, ecological, and social value. The subfamily Faboideae is positioned towards the base of the Leguminosae family and currently comprises about 335 species in 14 genera, mainly distributed in the pantropical regions. This subfamily includes the recently established genus Dendrobium, separated from the broad concept of the genus Indigofera. The genus name honors Mr. Dezhao Chen's contributions to Leguminosae taxonomy at the South China Botanical Garden.
Dendrobium is distributed in southern and southwestern China, the Indochinese Peninsula, South Asia, and Malaysia, with its distribution center in Guangdong, Guangxi, and Yunnan provinces in China. According to Clark et al., the genus includes 10 species and 3 subspecies. Despite morphological and palynological evidence indicating a series of shared derived characters in Dendrobium distinct from other Indigofera plants, the boundaries of the genus, infrageneric classification, interspecific relationships, and the evolution of key traits remain unclear or contentious, necessitating further research.
Researchers from the Plant Science Research Center of the South China Botanical Garden, including Dr. Dianxiang Zhang and Associate Researcher Tieyao Tu, collaborated with Professor Alexandre Antonelli from the Royal Botanic Gardens, Kew, and Professor Jun Wen from the Smithsonian Institution, to study the systematic relationships of all known species of Dendrobium, morphologically similar species of Pedilonum, and representative species of the Faboideae subfamily using morphological studies and plastid phylogenomics technology.
The research results establish the phylogenetic position of Dendrobium within the Faboideae subfamily, describe three new species and two new combinations, expanding the scope of Dendrobium to 15 species and 3 subspecies. The study also revealed through seedling growth experiments that bilobed leaf morphology is an ancestral trait of Dendrobium, while entire or slightly concave leaves are derived traits.
By conducting systematic phylogenetic analysis and generic delimitation of Dendrobium species based on morphological and plastid phylogenomics evidence, this study lays the foundation for research on the classification and evolutionary origins of the genus Dendrobium.
For more information on the related paper, visit: http://doi.org/10.1002/tax.13177
