[Molecular identification of Armillaria gallica by PCR-RFLP analysis]. 
Armillaria gallica is a symbiotic fungus in the cultivation process of Gastrodia elata and Polyporus. The rhizomorph of A. gallica invades the stalk of the G. elata or the Sclerotium of the Polyporus,and is digested and utilized by the latter,becoming their important source of nutrition.  Different nature of A. gallica affects the growth of G. elata and Polyporus.  The authors collected A. gallica from 13 commercially available regions and screened two A. gallica,A and B,at the genetic and metabolic levels,in order to distinguish between the two A. gallica market.  We have established convenient and effective DNA molecular identification method. By comparing the sequence differences between the A. gallica type A and type B invertase genes,PCR-RFLP primers were designed based on differential fragment.  Primer ZTM.F/ZTM.R can amplified A. gallica type A and B,producing a band of about 304 bp in length.  The restriction endonuclease EcoR V could recognize the difference sequence of A and B types of A. gallica.  The type B was digested to form two fragments,thereby specifically identifying the A. gallica as type B. The established methods of PCR-RFLP is an accurate identification method for A. gallica.  Therefore,in the cultivation process of G. elata and Polyporus,suitable strains can be selected according to different needs of variety,growth stage and ecological environment,and the yield and quality can be improved according to local conditions.