A PCR-BASED IDENTIFICATION METHOD FOR SPECIES OF ARMILLARIA

A portion of the Intergenic Spacer (IGS) of the ribosomal RNA operon o f 74 isolates of 11 Armillaria species from Europe and North America w as amplified using the polymerase chain reaction. Amplifications were made from scrapes of living mycelium without DNA extraction. Alu I dig ests of the amplified product were electrophoresed in agarose and stai ned with ethidium bromide. With few exceptions, each taxon had a uniqu e combination of restriction fragments. Most taxa had a single Alu I p attern, but two restriction patterns were seen among isolates of A. bo realis, A. cepistipes, A. gallica, A. tabescens, and A. mellea. Armill aria ostoyae, A. gemina, one of the A. borealis types, and one of the A. cepistipes types had identical sizes of Alu I fragments, but each o f these taxa could be distinguished by their polymorphisms after restr iction with the enzymes Nde I, Bsm I, or Hind II. European isolates of A. gallica had a distinct Alu I restriction pattern, but North Americ an isolates of this species had a restriction pattern identical to A. calvescens. IGS amplification products were obtained from 8-year-old s pore prints and dried basidiomes, as well as fresh wood decay without DNA extraction. The technique allows for identification from decayed w ood, basidiomes or mycelia of these Armillaria species in a single day .