The Application of Molecular Markers to Identify Edible Fungi: A Case Study of Tremella Fuciformis

Different Tremella fuciformis Berk (TFB) cultivars have different morphology and yield potential. For the identification of interspecies, the internal transcript spacer (ITS) sequences were generated by primers set BM36 and BM37 then sequenced. The results showed different bands at 570 bp for Auricularia auricula, 470 bp for Tremella fuciformis and 860 bp for Hypoxylon archeri. Among seven cultivars of Agaricus Blazei or Grifola frondosa which we collected from different area, they show same molecular bands by ITS method, 710 bp for all seven varieties Agaricus Blazei and 630 bp for all seven varieties of Grifola frondosa. The results showed that ITS can be used as an interspecies molecular marker while not for intraspecies. After sequence those bands generated by Tremella fuciformis cultivars, 99% similarity were found, and most of the different are single nucleotide polymorphism (SNP), very few molecular marker can be found by ITS method. A dual-suppression PCR method combine with adaptorligation PCR and suppression PCR were developed by this research to generate the primers set for SSR (simple sequence repeat). By using this method, the SSR can be detected by sequence the PCR products when using the special primers set design by this method. Currently, we have three primers sets can be used as molecular marker for Tremella fuciformis cultivars identification and the results had been confirmed by sequencing. The result shows that BM66 and BM93 primers set can generate SSR sequence: (AG)₁₄ for LT1, LT2, LT4, LT6 and SSR sequence: (AG)₁₃ for LT7, LT12. The primers set BM67 and BM92 generated SSR sequence: (C)₁₄(T)₁₈ for LT1 and LT4, (C)₁₅(T)₁₆ for LT2, (C)₁₃(T)₁₉ for LT6, (C)₁₄(T)₁₆ for LT7 and (C)₁₂(T)₁₉ for LT12. The result of primers set BM99 and BM102 showed two groups of the cultivar of Tremella fuciformis used in this research can- - be distinguished. The LT1, LT2 and LT7 belong to one group by DNA sequence tgt instead of gtctccatttgt which is replace in group LT4, LT6 and LT12. The result shows even it is very tiny different in intraspecies of Tremella fuciformis, but the methods which we used in this research can distinguish those cultivars.