A developed procedure to differentiate banana cultivars based on foliar resistance or susceptibility to Fusarium oxysporum f. sp. Cubense strain 1 infection was validated, attending to a phenotypical parameter (lesion area) and biochemical markers (free or cell wall-bound phenols, malondialdehyde and the rest of aldehydes, and proteins). Estimates were established from a data matrix considering the effects of fungus culture filtrates on leaves from eighteen cultivars. As part of the program for genetic improvement, an unprecedented discriminate analysis for differentiating resistant genotypes was carried out. Two discriminant functions were formulated for resistant and susceptible phenotypes, respectively. Every plant included in the matrix was evaluated according to both functions, reaching a 94.4 % of accuracy for assigning the corresponding phenotype (68 from 72). This is the first report on validating a method for differentiating banana resistance against the attack of the Fusarium oxysporum f. sp. Cubense strain 1 fungus, based on applying fungus culture filtrates on banana leaves. This method constitutes a useful tool for increasing the selection efficiency ex vitro irrespective of environmental or seasonal conditions for disease development. [ABSTRACT FROM AUTHOR]