RESEARCH ARTICLE
Complete chloroplast genomes of hemiparasitic genus Cymbaria :
Insights into comparative analysis, development of molecular markers,
and phylogenetic relationships
Yang Ma 1, Jordi López-Pujol 2, 3,
Dongqing Yan 1, Zhen Zhou 1, Zekun
Deng 1 and Jianming Niu 1, 4, 5
1 School of Ecology and Environment, Inner Mongolia
University, Hohhot 010020, China
2 Botanic Institute of Barcelona (IBB),
CSIC-Ajuntament de Barcelona, Barcelona 08038, Spain
3 Escuela de Ciencias Ambientales, Universidad
Espíritu Santo (UEES), Samborondón 091650, Ecuador
4 Ministry of Education Key Laboratory of Ecology and
Resource Use of the Mongolian Plateau, Hohhot 010020, China
5 Inner Mongolia Key Laboratory of Grassland Ecology
and the Candidate State Key Laboratory of Ministry of Science and
Technology, Hohhot 010020, China
Correspondence
Jianming Niu, School of Ecology and Environment, Inner Mongolia
University, Hohhot 010020, China; Ministry of Education Key Laboratory
of Ecology and Resource Use of the Mongolian Plateau, Hohhot 010020,
China; Inner Mongolia Key Laboratory of Grassland Ecology and the
Candidate State Key Laboratory of Ministry of Science and Technology,
Hohhot 010020, China
Email: 111964401@imu.edu.cn
Funding information
Major Science and Technology Projects of Inner Mongolia Autonomous
Region, Grant/ Award Number: 2019ZD008; National Natural Science
Foundation of China, Grant/ Award Number: 31860106 and 32260304
Abstract
Cymbaria L. is a small genus nearly endemic to the Mongolian
Plateau with only two hemiparasitic species. Cymbaria daurica L.
is an important herb “Xinba” in traditional Mongolian medicine.
However, C. daurica is often confused with its sister speciesCymbaria mongolica Maxim. because they only differ in anther
morphology. In addition, phylogenetic placement and reductive evolution
of this genus within the Orobanchaceae remain poorly resolved. Here, we
firstly sequenced two Cymbaria chloroplast genomes and then
conducted a comparative analysis among those of 54 Orobanchaceae
species. We found that the chloroplast genomes of Cymbariaspecies were characterized by pseudogenization/loss events of eightndh genes and a unique rbc L-mat K inversion. Unlike
the high-variability observed in holoparasites, Cymbaria and
other hemiparasites exhibited high similarity to autotrophs in genome
size, GC content, and intact genes. Notely, four pairs of specific DNA
barcodes (CymN1, CymN2, CymY, and CymR) were developed to distinguish
the herb C. daurica from its adulterant C. mongolica .
Phylogenetic analyses revealed that genus Cymbaria and theSchwalbea -Siphonostegia clade were grouped into the tribe
Cymbarieae. This tribe formed an independent sister clade to the
remaining parasitic lineages. Furthermore, the diversification of
monophyletic Cymbaria occurred during the late Miocene (6.72 Mya)
in the Mongol-Chinese steppe region. These findings provide valuable
information for regarding taxonomy, phylogeny and evolution ofCymbaria and can be used to validate the authenticity of the herb
“Xinba”.