Reactions of black bean seedlings and adult plants to infection by Fusarium oxysporum f. sp. phaseoli

Abstract

This study aimed to evaluate the resistance of 17 black bean genotypes artificially and naturally infected with Fusarium oxysporum f. sp. phaseoli under greenhouse and outdoor growing conditions, respectively, and compare the disease progress and bean yield components of the resistant line UFSC-01 and susceptible cv. Uirapuru. Five lines and one landrace were classified as resistant. Resistance classification of bean genotypes following root-dip inoculation in the greenhouse was tightly associated with the reactions in infected adult bean plants assessed on the 90th day. Disease severity rate in seedlings was positively correlated (0.93, P ≤ 0.01) with Fusarium wilt under outdoor conditions. Fungus more efficiently colonized the susceptible aerial tissues of cv. Uirapuru, resulting in earlier and stronger disease symptoms. Fop reduced the bean yield by decreasing the number of pods per plant and weight of seeds even in the resistant genotype UFSC-01 but more dramatically by decreasing the number of seeds per pod in the susceptible cultivar.