Gibberella fujikuroi mating population A and Fusarium subglutinans from teosinte species and maize from Mexico and Central America

Seed samples of maize (Zen mays ssp. mays) from Mexico and of teosintes (Ze a spp.), the nearest wild relatives of maize, from Mexico, Guatemala, and N icaragua were assessed for infection with Fusarium species. Strains similar in morphology to Fusarium moniliforme and F. subglutinans were the most fr equent isolates from maize and from teosinte species including Z. diplopere nnis, Z. luxurians, Z. mays ssp. mexicana, and Z. mays ssp. parviglumis. An alysis of fertility, vegetative compatibility and mycotoxin production iden tified 63% of the 70 F. moniliforme strains from teosinte as genetically di verse members of Gibberella fujikuroi mating population A, a common pathoge n of maize. The F. subglutinans strains from maize and teosinte were simila rly genetically diverse, but were not fertile with standard testers of G. f ujikuroi mating populations B and E, common pathogens of Poaceae, or of mat ing population H, which causes pitch canker disease of pine. Fifty-four per cent of the 80 F. subglutinans strains were fertile when crossed with femal e tester strains from teosinte and maize collected in a field at Netzahualc oyotyl in the state of Mexico. These strains from Mexico and Central Americ a may comprise a new and distinct G. fujikuroi mating population, but a str ain from the Netzahualcoyotyl field site was fertile with a strain of G. fu jikuroi mating population H from California. Thus, F. subglutinans from teo sinte and maize may have a close relationship to mating population H from p ine.