IN VITRO MUTAGENESIS IN BANANA (MUSA SPP.) IMPROVEMENT

Banana (Musa spp.) fruit production is threatened by several major pests and diseases such as black sigatoka, Fusarium wilt, burrowing nematodes and viral diseases like Banana streak virus, Banana bunchy top virus and Banana bract mosaic virus. The banana breeding program of edible bananas is hampered by high sterility, and very limited amounts of seeds. Few diploid banana clones produce viable pollen. However, the major problem with Musa germplasm enhancement is its low reproductive fertility and slow propagation rate. In vitro propagation of banana is successful and is routinely used for clonal propagation by commercial companies. On average, annually several millions of vitro plants can be produced. Somatic embryogenesis of banana has, however, not yet been commercially exploited due to highly genotypic dependence. Somatic embryogenic cell suspension is highly suitable for mutation induction and genetic transformation. Nuclear techniques have been used for mutation induction in 154 plant species, for the genetic improvement of both seed and vegetatively propagated crops. In our research project on banana at the International Atomic Energy Agency in Austria, several mutants were isolated for several traits, namely reduced height, tolerance to Fusarium wilt, early flowering, large fruit size and black Sigatoka tolerant types.