Genetic diversity analysis of Ganoderma species and development of a specific marker for identification of medicinal mushroom Ganoderma lucidum

The genetic diversity of 59 Ganoderma species from various regions was determined by different molecular markers, including the internal transcribed spacer (ITS) rRNA and a partial β-tubulin gene, as well as randomly amplified polymorphic DNA (RAPD) analysis.The size of the ITS rRNA gene regions from different Ganoderma species varied from 625 to 673 bp, and that of the partial β-tubulin gene sequence was 419 bp. A phylogenetic tree based on the ITS region, the partial β-tubulin gene, and the RAPD profiles revealed thatGanoderma lucidum strains could be classified into 1 group together with G. lucidum from Bangladesh. One fragment unique to G. lucidum was selected from the RAPD profile and then sequenced. One primer pair (designated as GSF and GSR) based on this specific fragment was designed to amplify a 559 bp DNA fragment within the sequenced region. A single band with the expected size of 559 bp was observed from G. lucidum, except for G.lucidum strains from China, Canada, and Taiwan. This specific marker for G. lucidumfrom RAPD analysis, also supported by the phylogenetic analysis of the ITS and partial β-tubulin gene sequences, will be useful for the PCR-based identification of G. lucidum in research applications as well as in the market.   Key words: Internal transcribed spacer, β-tubulin, medicinal mushroom, Ganoderma lucidum, randomly amplified polymorphic DNA (RAPD).