Applying target region amplification polymorphism markers for analyzing genetic diversity of Lentinula edodes in China.

The target region amplification polymorphism (TRAP) technique was utilized for assessing the genetic diversity of 55 wild strains and one cultivated strain of Lentinula edodes in China. From these strains, 932 DNA fragments were amplified using 12 primer combinations, 929 fragments (99.68%) of which were polymorphic between two or more strains. The average coefficient of pairwise genetic similarity was 0.696, within a range from 0.503 to 0.947. Cluster analysis and principal coordinate analysis separated the tested strains of L. edodes into two major groups. Group A was further divided into seven subgroups. In most cases, the strains from the same or adjoining regions could be preferentially clustered into small groups. The results from the average genetic similarity and the weighted average value of Shannon's Information Index among the tested strains of L. edodes from the same region revealed a vast genetic diversity in the natural germplasm found in China. Compared with the L. edodes strains from other regions, those found on the Yunnan Plateau, in the Hengduanshan Mountains, in Taiwan, South China, and Northeast China showed greater genetic diversity. The results of the present study indicated that the wild strains of L. edodes in China possessed abundant genetic variation, and the genetic relationships among them were highly associated with the geographic distribution. This is the first report demonstrating that TRAP markers were powerful for analyzing the genetic diversity of L. edodes, and the study lays the foundation for a further application of this remarkable technique to other fungi.