In the present study, we have assessed a collection of 34 banana cultivars for resistance against F. oxysporum f. sp. cubense (Foc) race 4 types and identified a range of resistance responses in the rhizomes. The rhizome appears to be a key factor in preventing the fungus from further spreading to other parts of the plant. We characterized diploid wild relative M. a. malaccensis lines that exhibit strong wilt resistance to Foc by inhibiting fungal growth in its rhizome. They are potential sources of ‘complete’ resistance to Foc race 4. Furthermore, contrasting resistance responses to different Foc race 4 types were observed. Phenotypic methods used in this study can help accelerate the efforts in breeding programs. Overall, this study paves the way for further characterizations in the defense mechanisms of Foc resistance at the cellular and molecular level in this important plant species.

15 out of the 34 banana cultivars assessed are accessions from ITC Genebank , the 19 remaining ones are from different genebanks and thus not listed here.