Visualization of ribosomal DNA loci in spore interphasic nuclei of glomalean fungi by fluorescence in situ hyhridization

Fluorescence in situ hybridization (FISH) was applied to interphasic nuclei isolated from spores of four species of AM fungi : Scutellospora castanea, Glomus mosseae, Glomus intraradices and Gigaspora rosea. Ribosomal DNA loc i were visualized using digoxigenin-labeled 25 S rDNA probes obtained by ne sted PCR. Several hybridization sites were detected per nucleus and an inte rnuclear variability was observed in the number of loci. This is the first report of successful application of FISH to analyse the genomes of glomalea n fungi.