EVALUATION OF THE GENETIC DIVERSITY IN DI PLOID BANANAS (MUSA SPP)

Most cultivated bananas are triploids. Diploid bananas are important t o breeding programmes. We analyzed diploids to investigate the genetic organisation of the Musa species complex. Restriction fragment length polymorphism (RFLP) was used to analyze the genetic diversity of 160 diploid bananas. 70 seminiferous clones (wild bananas) of the species Musa acuminata, M balbisiana and M schizocarpa and 90 parthenocarpic c lones (cultivars) were studied using 30 mapped single copy nuclear pro bes. Alleles specific to the 3 species studied were found. M acuminata is the most polymorphic: its genetic structuration is discussed. M sc hizocarpa appeared to be very similar to M acuminata banksii, and M ba lbisiana is more divergent. All the diploid parthenocarpic bananas con tain M acuminata alleles. This confirm the involvement of M acuminata in the origin of parthenorarpy. Some cultivars were proved to be hybri ds between M acuminata and M schizocarpa.