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Seeds of Trade

 
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Product: Bananas and Plantains

Other products:  
   Bananas and Plantains belong to the category Food crops
   and originated in South East Asia

 SUMMARY
 WILD RELATIVES
 ORIGINS
 EARLY USES
 TRANSFER AND SPREAD
 AGRICULTURE
 MODERN CONTEXT
  POST HARVEST


Wild relatives

All of the widely cultivated bananas (dessert bananas and plantains) belong to the single species Musa paradisiaca L. The species is of hybrid origin and is derived from wild species of the genus Musa, of the family Musaceae. Because cultivated bananas are known to be of hybrid origin, the scientific name is often written as Musa x paradisiaca L., where the 'x' indicates hybridity.

Although plantains and dessert bananas are the same species, they are treated differently in terms of use. A plantain is defined as a banana that is cooked rather than eaten raw and has about 65% moisture content. Dessert bananas are eaten raw and have about 83% moisture content. Banana is commonly used as a collective term for both plantains and dessert bananas.

The genus Musa has been divided into four sections:

  • Eumusa - this section has most of the cultivated bananas and plantains, with 13-15 wild species centred within South-East Asia.
  • Rhodochlamys and Callimusa - two sections with less than 10 wild species each, both with centres of origin in South-East Asia. One species from China, Musa coccinea Andr., is grown as an ornamental in tropical gardens.
  • Australimusa - a section of less than 10 wild species that includes the Fe'i bananas and Manila hemp, Musa textilis Née. Their native distribution is in the Pacific area, including New Guinea.

All wild species of banana are diploid. cultivars, however, are generally triploid, but rarely tetraploid. The genome of all cultivars is a combination of two different ancestral genomes, usually termed A and B. All the cultivated bananas of section Eumusa are derived from only two wild progenitors ( genome donors) - Musa acuminata Colla (AA) and Musa balbisiana Colla (BB). Most dessert bananas are AAA and most plantains are AAB; some other cultivars have the composition ABB, with more Musa balbisiana genes. This means that the triploid cultivars have either two doses of Musa acuminata genes and one dose of Musa balbisiana genes (AAB genotypes), one dose of Musa acuminata genes and two doses of Musa balbisiana genes (ABB genotypes), or three doses of Musa acuminata genes (AAA genotypes). A few cultivars, primarily grown in South-East Asia, are derived solely from Musa balbisiana; these are said to be members of the BBB group.

The wild AA banana (Musa acuminata) became edible as a result of the evolution of parthenocarpy and female sterility. These characteristics produced pulpy, seedless fruit that was favoured and selected for vegetative propagation. After polyploidy, fertile male AA and AAA bananas hybridised with wild BB bananas, and modern cultivars arose. They were cloned and propagated, thus transforming bananas from jungle weeds into a productive crop.

Musa acuminata is a complex species with several subspecies, whose centre of diversity is in the Malesian area, where four of its five subspecies overlap.

Musa balbisiana has a natural distribution in southern and South-East Asia, ranging from India in the west to New Guinea and New Britain in the east.

The Fe'i bananas are an independently derived group of cultivated bananas found only in the Pacific (including New Guinea). These bananas are all diploid and have been derived from wild species from New Guinea (Musa maclayi F. Muell.) and the Solomon Islands. The best known set of cultivars is found on Tahiti - these are thought to be derived from the wild species Musa troglodytarum L.