Résumé
An international initiative to apply genomic technologies to the sustainable improvement of the banana and plantain, "the Global Musa Genomics Consortium, was launched in July 2001. The aim is to develop public freely-accessible resources and use the new knowledge and tools to improve the crop through targeted breeding strategies. The result will be new Musa varieties that will be high yielding whilst responding to local needs and pathogen attacks. As a first step towards characterizing and sequencing the banana genome, three HindIII BAC libraries were constructed and characterized from the following genotypes: Musa acuminata 'Calcutta 4', Musa acuminata 'Cavendish', Musa balbisiana 'Pisang Klutuk Wulung'. The three BAC libraries have been anchored to the existing genetic map using a set of single-copy RFLP markers, each representing one linkage group. The first objective is to provide a set of entry points for the sequencing of the Musa acuminata genome and compare it with the available rice genome. High density filters of the Calcutta4 BAC library were screened with cDNA heterologous probes, previously shown to cross-hybridize with banana genomic DNA (EGRAM probes). Selected banana BAC clones are in the process of being characterized and subcloned for sequencing. The availability of BAC libraries for the A and B genomes of Musa also enabled the use of individual BAC clones as distinct chromosome-specific landmarks and the construction of the first banana "molecular karyotype". It also allowed the comparison between the two Musa species and the integration of the physical and genetic maps by BAC-FISH technology. The three BAC libraries are a publicly available resource and represent a critical tool to achieve the goals of the recently created Global Musa Genomics Consortium. The MUSABAC platform was supported by CIRAD, INIBAP, EMBRAPA, Agropolis International GA AVCR (project no. A603824) and the French Ministry of Foreign Affairs (COCOP project 17/01). (Texte intégral)