Plastome-based Phylogenomic analyses provide insights into the germplasm resource diversity ofCibotiumin China

Abstract

AbstractGermplasm resource is the source of herbal medicine production. Cultivation of superior germplasm resources helps to resolve the serious conflict between long-term population persistence and growing market demand by producing materials with high quality consistently.Cibotium barometzis the original plant of cibotii rhizoma (“Gouji”), a traditional Chinese medicine used in the therapy of pain, weakness, and numbness of lower extremity. Long-history use ofCibotiumhas rendered wild populations of this species declined seriously in China. Without sufficient understanding of species and lineage diversity ofCibotium, it is difficult to propose a targeted conservation scheme at present, let alone selecting high-quality germplasm resources. In order to fill such a knowledge gap, this study sampledC. barometzand relative species throughout their distribution in China, performed genome skimming to obtain plastome data, and conducted phylogenomic analyses. We constructed a well-supported plastome phylogeny of ChineseCibotium, which showed that three species with significant genetic difference distributed in China, namelyC. barometz,C. cumingii, andC. sino-burmaense, a cryptic species endemic to NW Yunnan and adjacent region of NE Myanmar. Moreover, our results revealed two differentiated lineages ofC. barometzdistributed in the east and west side of a classic phylogeographic boundary that probably shaped by monsoons and landforms in China. We also evaluated the resolution of nine traditional barcode loci, and designed five new DNA barcodes based on the plastome data which can discriminate all these species and lineages of ChineseCibotiumaccurately. These novel findings integrated genetic basis will guide conservation planners and medicinal plant breeders to build systematic conservation plans and exploit germplasm resources ofCibotiumin China.