Genetic Diversity and Population Structure of Traditional Chinese Herb “Chai-Hu” Resources Using Genome-Wide SNPs Through Genotyping-By-Sequencing

Bupleurum (named “Chai-hu”) is an important traditional Chinese medicine resource in China. It has been widely used since ancient times and has antipyretic, analgesic and cholagogic functions, but there is little research on its genetic diversity. In this study, genotyping-by-sequencing (GBS) was used to detect SNP loci in 39 Bupleurum germplasm resources from different regions in China and analyse their genetic diversity. A total of 25.1 Gb of data was obtained by sequencing, with an average of 0.64 Gb per sample. After screening, 83898 high-quality SNPs were obtained. The results of genetic research were obtained by phylogenetic tree, principal component analysis and population structure analysis, and the 39 experimental materials were divided into three groups. The average observed heterozygosity and expected heterozygosity of Bupleurum populations were 0.24 and 0.17, respectively, indicating that Bupleurum populations from five different provinces had a low level of genetic diversity. Population nucleotide diversity analysis and analysis of molecular variance showed that the percentage of intrapopulation variation was 120.88%, while the percentage of interpopulation variation was only 2.46%. There was relative aggregation of Bupleurum samples with the same geographical origin, but the division of population structure was not completely correlated with sample origin. The results showed that the genetic diversity of the materials was low and that the genetic variation was narrow. This provides a good basis for the genetic breeding and protection of species diversity of Bupleurum .