Banana breeding

Abstract

The first attempt at breeding bananas through hybridization, in the 1920s was triggered by the devastation of the export banana ‘Gros Michel’ by Fusarium wilt. Conventional breeding despite being hindered by several plant based constraints has been responsible for the production of a whole range of hybrids resistant to diseases and pests. The approach commonly adopted aims at developing new tetraploid varieties by crossing triploids with wild or improved diploid clones with resistance, or secondary triploids derived from crosses between the developed tetraploids and the diploid clones. The limitations of the 3x/2x strategy are low gametic fertility of the triploid variety to be improved. This has led to the development of an alternate pathway, which targeted the development of triploid hybrids directly from crosses involving diploid and doubled diploid varieties. The method exploited the male and female fertility status of doubled diploids which otherwise are sterile at the diploid level. Following the 3x/2x method, hybrids with yield advantage and resistance to biotic stresses developed by major breeding programmes have been adopted in many countries, which was facilitated by the International Musa Testing Programme. The new insight gained in Musa genetic diversity through molecular tools provided key inputs, useful for the selection of parental combinations. Development of molecular markers linked to major traits is expected to speed up the improvement process. Mutation breeding is offering a unique, alternative approach for the improvement of banana has also been employed to develop new cultivars.