XVI International Botanical Congess

Little is known about the population structure of late-stage ecto- mycorrhizal fungi especially with regard to genotype stability over relatively long periods of time. To determine if basidiomata of the late stage fungus Russula brevipes expressed the same genotype over a ten year period, genotypes of basidiomata from the same subpopulation collected in 1988 and 1998 were examined using Amplified Fragment Length Polymorphisms (AFLPs) with three primer combinations. The results show that the genotype had changed substantially over the ten year period. This suggests that different alleles arose in that sub- population due to migration, recombination, or that there is more than one genotype associated with host roots at that particular locale. Additional studies are underway to assess the population structure of R. brevipes basidiomata and mycorrhizae and the effect that spore germination might have on genetic diversity.