The nuclear rDNA intergenic spacer of the ectomycorrhizal basidiomycete Laccaria bicolor: structural analysis and allelic polymorphism.

The nuclear rDNA intergenic spacer (IGS) of the ectomycorrhizal basidiomycete Laccaria bicolor was amplified and sequenced to identify the source of its intraspecific polymorphism. The IGS was amplified by PCR in several L. bicolor strains and shown to exhibit multiple bands and length polymorphism.

Rapid identification of genetic variation of ectomycorrhizal fungi by amplification of ribosomal RNA genes.

There is a clear requirement to develop sensitive methods for detecting denned isolates of ectomycorrhizal fungi within the complex microbial communities of natural ecosystems and reforestation sites. We present a method that permits the rapid identification of an ectomycorrhizal isolate using enzymatic amplification (polymerase chain reaction) of DNA extracted either from pure cultures or ectomycorrhizas. A set of oligonucleotide primers capable of amplifying full-length nuclear 17S and 25S ribosomal RNA genes, together with the ribosomal internal transcribed spacer and intergenic spacer, have been designed and could be used for amplifying target sequences from a wide range of ectomycorrhizal genera.