Herbaria preserve plant specimens and associated data for scientific research. These collections include rare and endangered species that may have been collected only once and could be decades to centuries old.
Currently, Pseudobartsia yunnanensis is treated as a synonym of Pseudobartsia glandulosa. It is the only material of Pseudobartsia in China available for any molecular test of the identity of Pseudobartsia as an independent taxonomic entity. Xizangia is another monotypic genus in the Pterygiella group. The correct placement of Pseudobartsia and Xizangia needs to be confirmed.
In a study published in Journal of Systematics & Evolution, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) and Kunming Institute of Botany (KIB) formally propose two new tribes, Brandiseae and Pterygielleae, in supporting the existence of independent Brandisia and Pterygiella group clades.
The researchers obtained genomic data from an available specimen of Pseudobartsia glandulosa known in China from only a single collection taken in Yunnan in 1940. They reconstructed the first whole-plastome phylogeny of Orobanchaceae covering all nine clades, using high-throughput short-read sequencing, and then assembled a complete chloroplast genome and nuclear ribosome DNA region in the study.
They found that the newly assembled three plastid DNA regions (atpB-rbcL, rpl16, and trnS-G) and nuclear ribosomal internal transcribed spacer (nrITS) of Pseudobartsia glandulosa were more than 99.98% similar to published sequences obtained by target sequencing.
Most plastid genes appear to be linked and evolving as a unit. The supermatrix yielded the most robust results for assessing phylogenetic relationships in Orobanchaceae.
The study recommends reinstatement of Pseudobartsia and Xizangia as independent genera, and further supports the transfer of Phtheirospermum glandulosum into Pseudobartsia as Pseudobartsia glandulosa, and the transfer of Pterygiella bartschioides into Xizangia as Xizangia bartschioides.
YU Wenbin Ph.D Principal Investigator
Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China