摘要：To assess the reaction of maize landrace seedlings to inoculations of Fusarium spp. derived from different geographic origins, inoculations were performed to substrates in which seeds were germinated, and the severity of damage and the degree of resistance and/or tolerance at the seedling stage were later evaluated. In this study, 57 populations of maize were collected in the states of Oaxaca, Puebla, Tlaxcala, Guerrero and Estado de Mexico, Mexico, and at same time five sources of Fusarium spp. inoculum were obtained. The maize collection and inocula were then evaluated in a bi-factorial arrangement of treatments in a randomized complete block design with four replications. Significant differences were observed in the virulence of the isolates from each geographic region (p < 0.01). The inoculum consisting of isolates from Estado de Mexico proved to be the most virulent, whereas the inoculum from the state of Guerrero caused the least amount of damage to maize seedlings. The length of the roots and aerial portions of the seedlings were reduced due to the effect of the pathogen in comparison with seedlings that emerged in the substrate without inocula. The maize populations responded differently to the pathogen depending on its geographic origin, as the maize plants expressed different amounts of damage caused by the various inocula to which they were subjected. No direct relationship was observed between the virulence of the inoculum and the resistance/tolerance to the disease of populations from the same origin; in some cases, such as that of Tlaxcala, pathogens of the same origin caused more damage to maize from that region.
