Assessment the genetic diversity of Auricularia strains by two PCR-based typing methods.

Two PCR-based methods, enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) and randomly amplified polymorphic DNA (RAPD), were adopted for differentiating Auricularia strains. Taken the similarity coefficient as 75%, 29 strains of three Auricularia species were grouped into 6 and 9 clusters by RAPD and ERIC, respectively. The dendrogram from ERIC exhibited two distinct parts, one representing A. auricula and the other A. polytricha, but the dendrogram from RAPD failed to clearly distinguish between these two species. However, both methods similarly revealed high homology between A. fuscosuccinea and A. auricula. The homology relationships among the three species obtained from ERIC were validated by Southern hybridization. The analyses showed that RAPD is able to differentiate mainly at the species level, while ERIC is effective at the strain level and therefore more consistent with cultivation characteristics. The results indicate that the method of ERIC-PCR is more rapid and reliable than RAPD, and may substitute for RAPD in research related to the genetic identification and genetic diversity in Auricularia.