Healthy germplasms for sustainable agriculture, the case of an important clonal crop: banana

Banana plants (Musa sp.) bear the most important tropical fruit in the world, in terms of production and consumption, and it is a staple food for half a billion people across the planet. The most important viral diseases infecting Musa sp. are BBTV, BSV, BBrMV, CMV and BanMMV. Therefore, a virus free planting material is crucial to ensure a proper food security and to avoid significant economic losses. To answer this need, an ongoing multiyear collaboration has started between the Bioversity’s International Musa Germplasm Transit Centre (ITC - KULeuven, Belgium) and the recognized Bioversity’s Germplasm Health Unit (GHU - University of Liège, Belgium). ITC is hosting the largest and most widely used collection of Musa germplasm with more than 1,500 accessions. In the framework of this project, 265 accessions from the ITC collection and infected by at least one virus have been selected by both partners, for indexing and sanitation processes. Viruses were mainly BSV and BanMMV, and less commonly but to a more critical extent BBTV and BBrMV. The virus sanitation protocols developed by the GHU are currently being applied to these accessions. These protocols include meristem culture, thermotherapy and chemotherapy to eradicate the virus from the plant. After sanitation, the plants are grown in the greenhouse before virus full indexing. To date, at least one plant/accession tested negative has been grown for 55% of the accessions (success rate for the sanitation). For 12% of the accessions, no virus-free material has been identified. For these accessions, and for the 33% of other accessions, the sanitation process is still ongoing. Among the sanitized accessions, 63% of the accessions that were subjected to thermotherapy were sanitized, whereas the sanitation occurred in 35% of the accessions receiving the chemotherapy.