High Genetic Diversity in Wild Culinary-Medicinal Wood Ear Mushroom, Auricularia polytricha (Mont.) Sacc., in Tropical China Revealed by ISSR Analysis

Abstract

The genetic diversity of 40 wild Auricularia polytricha strains within ten natural populations in tropical China and five cultivated strains were analyzed by using twelve inter-simple sequence repeat (ISSR) primers. At the species level, the percentage of polymorphic loci (P) = 99.8%, the effective number of alleles (Ne) = 1.3569, Nei's gene diversity (H) = 0.2398, Shannon information index (I) = 0.3896, and total genetic diversity (Ht)= 0.2346 indicate a high level of genetic diversity in wild A. polytricha. At the population level of the wild fungus, P = 43.51%, Ne = 1.2675, H = 0.1702, I = 0.2504. However, the genetic diversity of cultivated strains was the lowest of all populations (Ne = 1.1584, H = 0.0940, I = 0.1440). A moderate degree of genetic differentiation (G(st) = 0.347) among the sampled wild populations was detected based on Nei's gene diversity analysis, suggesting that 65.3% of variation existed within this population. The high genetic variation level within wild populations may mostly result from a low level of gene flow (N = 0.9408) and random genetic drift.