IDENTIFICATION OF SOME ECTOMYCORRHIZAL BASIDIOMYCETES BY PCR-AMPLIFICATION OF THEIR GPD (GLYCERINALDEHYDE-3-PHOSPHATE DEHYDROGENASE-ENCODING) GENES

Degenerated oligonucleotide primers, designed to flank an approximatel y 1.2-kb fragment of the glycerinaldehyde-3-phosphate dehydrogenase-en coding (gpd) gene from asco- and basidiomycetes, were used to amplify and sequence the corresponding gpd-fragment from several species of th e ectomycorrhizal fungal taxa Boletus, Amanita and Lactarius. The ampl ified fragment from a given taxon could be distinguished from that of others by both restriction nuclease cleavage analysis as well as by So uthern-hybridization. A procedure for labelling DNA-probes with fluore sceine-12-dUTP by the polymerase chain reaction was developed. These p robes were used in a non-radioactive hybridization assay, which was ab le to detect 2 ng of chromosomal DNA of L. deterrimus specifically on slot-blots. Taxon-specific amplification could be acchieved by the des ign of specific oligonucleotide primers. The application of the gpd ge ne for the identification of mycorrhizal fungi under field conditions was demonstrated, using Picea abies (spruce) mycorrhized roots harvest ed from a north-alpine forest area as well as from a plant breeding ga rden. We conclude that gpd can be used to detect ectomycorrhizal fungi during symbiotic interaction.