Musa (genus) - Systematics and Taxonomy

Systematics and Taxonomy

Ernest Entwistle Cheesman carried out a major revision of the Musaceae in the 1940s. The genus Musa was traditionally divided into five sections (Ingentimusa, Australimusa, Callimusa, Musa and Rhodochlamys) but these were reduced to three in 2002. Previously, the 2n = 20 chromosome species were separated into the sections Australimusa and Callimusa and the 2n = 22 chromosome species were separated into the sections Musa and Rhodochlamys. Recently, studies by Carol Wong and colleagues in Singapore have revealed that genetic differences between each section in the same chromosome group are smaller than those within each section. This means that the traditional separation of the sections can no longer be substantiated. Wong's studies do, however, maintain the separation between the 20 and 22 chromosome species. At present the 14 chromosome Ingentimusa section remains distinct.

A number of distinct groups of edible bananas have been developed from species of Musa. By far the largest and now the most widely distributed group is derived from Musa acuminata (mainly) and Musa balbisiana either alone or in various hybrid combinations. The next but much smaller group is derived from members of section Callimusa (previously classified as Australimusa) and is restricted in importance to Polynesia. Of even more restricted importance are small groups of hybrids in Papua New Guinea; a section Musa group to which Musa schizocarpa has also contributed, and a group of section Musa × section Callimusa hybrids.