RESUMO
Maize plants infected by Ustilago maydis develop galls known as "cuitlacoche", a food product appreciated in the Mexican gastronomy. The virulence of different U. maydis isolates was assessed, as well as the development of the infection on one commercial maize variety. Sporidia were isolated of wild galls collected in Mexico. Sexual compatibility patterns were determined using the Fuzz reaction, showing a 1:1:1:1 segregation of mating type specificities. Ten U. maydis compatible strains were selected on the basis of their virulence, namely: four wild-type compatible sporidia, one multi-teliosporic strain, two hybrids between wild-type and tester strains, and three tester strains. Maize plants of a commercial hybrid (Tornado XR™) were inoculated with these strains of U. maydis, using a randomized complete block experimental design. Phenological and phenotypic characteristics of plants, as well as production, quality and sensory attributes of the resulting galls, were evaluated. Greater yields of galls were recorded in tester strains (incidence >90 %, severity >80 %, productivity >12 t/ha), a hybrid strain (EM1-6 × FB1) [incidence 82.6 %, severity 51.8 %, productivity 5.6 t/ha] and a wild-type strain (EM4-10 × EM2-4) [incidence 68.2 %, severity 44.0 %, productivity 4.8 t/ha]. Wild-type strains showed better flavor, characterized by less bitterness and acidity, but prevailing sweet, umami and maize flavor.
