A research team from Shenzhen Fairy Lake Botanical Garden has made a breakthrough in the research of liverworts. Related results were published on the scientific journal Annals of Botany, according to the botanical garden.
The thesis was titled “Phylotranscriptomics of liverworts: revisiting the backbone phylogeny and ancestral gene duplications.”
Liverworts, also traditionally called Hepaticae, are one of the monophyletic groups that are descendants of some of the first land plants. It is estimated that there are over 7,300 species of liverworts around the world.
According to the thesis, the backbone relationships, such as the phylogenetic position of Ptilidiales, and the occurrence and timing of whole genome duplications, are still contentious.
The paper is based on analyses of the newly generated transcriptome data for 38 liverworts and complemented with those publicly available.
The research team reconstructed the evolutionary history of liverworts and inferred gene duplication events along the 55-taxon liverwort species tree.
The phylogenomic study provided an ordinal-level liverwort nuclear phylogeny and identified extensive gene tree conflicts and cyto-nuclear incongruences. Moreover, gene duplication analyses indicated no evidence of whole genome duplication events along the backbone phylogeny of liverworts.
With a broadened sampling of liverwort transcriptomes, the team reevaluated the backbone phylogeny of liverworts and provided evidence for ancient hybridizations followed by incomplete lineage sorting that shaped the deep evolutionary history of liverworts.
The lack of whole genome duplication along the deep evolution of liverworts indicated that liverworts might represent one of the few major embryophyte lineages whose evolution was not driven by whole genome duplications, according to the paper.
The first author of the thesis is Dong Shanshan from the South Asia tropical plant diversity key lab of Shenzhen Fairy Lake Botanical Garden. Other authors include Zhang Li, a researcher from the garden, Yu Jin from BGI Research and professor Bernard Goffinet from the University of Connecticut.