Genetic diversity and main functional composition of Lingzhi strains from main producing areas in China

Abstract In this study, we used genotyping by sequencing (GBS) to examine the genetic diversity of 22 strains of Lingzhi and the quality differences in 15 fruit bodies of Lingzhi from different Chinese regions. The phylogenetic trees of 22 strains were constructed based on ITS (Internal transcribed spacer) and SNP (single nucleotide polymorphism). Moisture, ash, water-soluble extracts, alcohol-soluble extracts, polysaccharides, and triterpenoids from 15 fruit bodies of Lingzhi were detected and analyzed based on Chinese Pharmacopoeia and the US Pharmacopoeia references. Moreover, the monosaccharide composition of polysaccharides was studied using PMP-HPLC, and the effect of polysaccharides on the proliferation rate of splenocytes was investigated in vitro. The identification results of these strains by the phylogenetic trees which were constructed based on ITS sequences and SNPs showed that most of the strains applied in the main producing areas of Lingzhi in China were accurate except for a few inaccurate strains. The moisture, ash, water and alcohol soluble extractive, polysaccharide and triterpenoid content of all samples were meet the requirements of the Chinese Pharmacopoeia, while the polysaccharide and triterpenoid content of less than half of the samples meet the requirements of the U.S. Pharmacopoeia. The polysaccharide extracted from these samples have different effects on the proliferation rate of spleen cells. To sum up, this is the first study that reported on the differences in Lingzhi strains from the main producing areas in China. The quality of some fruit bodies did not meet the pharmacopeia requirements, and wrong strains were used in some production areas; thus, strains should be given special attention before legal processing.