Population Genetic Analyses of Gibberella fujikuroi Isolated from maize in Korea

We analyzed 88 strains of Gibberella fujikuroi (Analmorph: Fusarium section Liseola) from maize in Korea for mating population, mating type, fumonisin production vegetative compatibility, and random amplified polymorphic DNA (RAPD) patterns. We found 50 strains that were MATA-2, 22 that were MATA-1, 1 that was MATD-1, and 15 that were not reproducibly fertile with any of the mating type testers. Of the 50 MATA-2, 15 were female fertile, while 10 of the 22 MATA-1 strains were female fertile. A total of 1,138 nitrate non-utilizing (nit) mutants were recovered from a total of 88 strains. These strains were grouped into 39 vegetative compatability groups (VCGs) by demonstrating heterokaryosis between nit mutants. A single maize ear could be infected by more than one VCG of F. moniliforme. RAPD analysis measured genetic diversity among 63 strains of F. moniliforme. Several VCGs were distinguished by RAPD fingerprinting patterns. Most strains produced significant levels of fumonisins. However, 6 MATA-2 strains from a single VCG produced higher levels of fumonisin $\textrm{B}_3$ than that of fumonisin $\textrm{B}_1$ or $\textrm{B}_2$. From these data, we concluded that most Korean strains of F. moniliforme associated with maize belonged to mating population A and produced significant levels of fumonisins. Futhermore, RAPD analysis could differentiate strains associated with different VCGs.