Résumé
Tropical race 4 (^R4) of Fusarium oxysporum f. sp. cubense (Foc) presents a major concern for current banana production worldwide. Two strategies are critical for controlling this pathogen: a) preventing its spread to TR4-free areas and b) identifying resistant banana genotypes. The team has established and validated a reliable and rapid greenhouse bioassay, and used it to characterize ^R4 resistance in eight banana genotypes [Gros Michel (AAA); 'Silk (AAB), 'Prats (AAB), 'Pahang (AA, Musa acuminata ssp. malaccensis), 'CIRAD 930 (AA, DH Pahang), 'Matavi'a (ABB), 'Banksii (AA) and 'Tuu Gia (AA)], where 'Grande Naine (AAA) was used as a susceptible control. All genotypes were highly susceptible, but 'CIRAD 930 and 'Pahang showed partial resistance, evidenced by highly reduced rhizome discoloration. Subsequently, we evaluated a segregating population of 'Pahang (N=80) and observed three phenotypic groups a) susceptible, b) moderately resistant and c) resistant. We concluded that the bioassay is a reliable method to screen banana germplasm for ^R4 resistance under greenhouse conditions and that 'Pahang is an important source of resistance to Foc ^R4 that should be further explored. (Résumé d'auteur)