BOTANY AND DISTRIBUTION

The genus Musa belongs to the Musaceae family, and ‘banana plant’ describes all wild species, landraces and cultivars. ‘Plantain’ describes landraces whose fruit is eaten cooked, mainly in Central and West Africa (Simmonds 1962; Stover and Simmonds 1987). Cultivated banana exhibits parthenocarpic fruit development, a marked degree of sterility, and vegetative propagation. Wild banana (Table 6.1) exhibits sexual reproduction and vegetative propagation by ratooning. Common names are numerous (Jarret 1990), and in Uganda alone Karamura and Karamura (1994) have identified 566 names used just for the subgroup Mutika/Lujugira of the AAA group.

Virtually all the cultivars derive from the Eumusa section, which Simmonds and Weatherup (1990) have divided into two subsections, Eumusa (1) and Eumusa (2). Edible banana plants derived from the Eumusa section are mainly based on the recognition of a single source for most varieties, Musa acuminata (A genome) and M. balbisiana (B genome) (Cheesman 1947,1948; Dodds and Simmonds 1948). The Australimusa section is important as a genetic source of domestication for textile fibres (Abaca or Manila hemp) and the edible Fe'i or Fehi cultivars, found only in the Pacific Islands. Callimusa and Australimusa have a basic chromosome number of 10 (2n=20) while Eumusa and Rhodochlamys have 11 (2n=22). The Simmonds and Shepherd (1955) classification associates the ploidy level (2n=2x, 3x or 4x) with a different contribution of genomes of two species.