The cultivars of the Cavendish subgroup, which are somaclones, are responsible for more than 50% of world production. They are all susceptible to black stripe disease (BSD), a recent pandemic caused by the foliar fungus Pseudocercospora fijiensis. To help select resistant cultivars, we first improved the phenotyping test under controlled conditions. Leaf fragments inoculated on survival medium in Petri dishes are studied for 2 months by scanning and via image analysis software to allow analysis of up to 1200 units per experiment (Perez-Vicente and Carreel et al., 2021). This test allowed a quantitative characterization of the resistance/tolerance/susceptibility of 62 banana plants, genitors of the CIRAD breeding program or accessions of the CRB Plantes Tropicales Antilles. These banana plants were tested against 12 strains of P. fijiensis representative of the world and molecular diversity. The study of a progeny between an accession identified as susceptible and a progenitor identified as highly tolerant allowed the identification of the 1st QTLs of resistance to MRN, 2 of which are potentially interesting for marker-assisted selection.

This work was carried out in collaboration with the GABA team of the UMR AGAP and the FBI team of the UMR PHIM. It was financially supported by the Ecophyto plan project 'DuRéBan' and by the Guadeloupe region project 'PBD2'.

• Perez-Vicente Luis and Carreel Françoise, Roussel Véronique, Carlier Jean, Abadie Catherine. 2021. Guidelines for the evaluation of Pseudocercospora resistance to leaf spots of banana. In: Practical guidelines for early screening and field evaluation of banana against Fusarium wilt, Pseudocercospora leaf spots and drought. Dita Miguel A. (ed.), Teixeira Luiz (ed.), Li Chunyu (ed.), Zheng Sijun (ed.), O'Neill Wayne (ed.), Daniels Jeff (ed.), Perez-Vicente Luis (ed.), Carreel Françoise (ed.), Roussel Véronique (ed.), Carlier Jean (ed.), Abadie Catherine (ed.), et al. Montpellier : Biodiversity International, 20-63. ISBN 978-92-9255-192-6