Genetic Characterization of Fusarium Populations From Native and Agricultural Plants In Kansas.

Vegetative Compatibility Groups (VCGs) analysis is commonly used to study the population biology of fungi. When hyphae from two isolates fuse to form a stable heterokaryon (two nuclear types per cell) they are considered to be vegetatively compatible and are in the same VCG. Those that do not form stable heterokaryons are not vegetative compatible and are in different VCGs. VCG analyses will be used to characterize strains of Fusarium from plant populations in Kansas. The first step in creating a VCG is to generate chlorate-resistant nit Nitrate-non-utilizing mutants. nit mutants will be created by growth on chlorate containing medium and the nature of the mutation determined by growth on medium with different sources of nitrogen. Several classes of nit mutants can be distinguished based on their ability to utilize different nitrogen sources. Mutants classified as nit1, nit3, and NitM will be paired in all combinations to determine ability to form stable heterokaryons. Once classified, complementary nit mutants (e.g. nit1 X nit3) derived from the same strain will be paired. If as a result of the pairing a line of robust growth appeared, the strains will have formed a heterokaryon. If a line of thin growth appears where the colonies meet, then no heterokaryon formed. Then, complementary nit mutants derived from different strains will be paired. If a stable heterokaryon is formed, the strains will be considered to be in the same VCG. All strains in the sampled populations will be paired to determine VCG relationships.