Intersporal Genetic Variation of Gigaspora margarita, a Vesicular Arbuscular Mycorrhizal Fungus, Revealed by M13 Minisatellite-Primed PCR.

Spores of vesicular arbuscular mycorrhizal (VAM) fungi contain thousands of nuclei. In order to understand the karyotic structure of a VAM fungus spore, the genetic variation of the first generation of spores from a VAM fungus (Gigaspora margarita) was examined. Spores originating from both single- and multispore inoculations of the species G. margarita were analyzed by M13 minisatellite-primed PCR. In both cases, different fingerprints were obtained from individual spores with few spores exhibiting similar fingerprints. These results can be explained only by a heterokaryotic status of the nuclear population within a spore.