Cultivation

The banana is a tropical plant. For export, primarily the crossed species Musa x paradisiaca is cultivated. Until the 1960s this status was held by the "Gros Michel"; however, due to fungal disease known as "Panama disease", use of this variety was abandoned. Today, the most important commercial grade is the "Cavendish", in which the fungal disease appears only lightly.

The main cultivation countries are India (21,7 million tonnes in 2007) followed by China, the Philippines and Brazil (each with 7 million tonnes in 2007). In temperate zones, for example in the south of Spain and in Cyprus, less sophisticated Cavendish species thrive.

Utilization

The fruit is mostly consumed raw or processed into:

• fruit additives, fruit yoghurt, banana milk, fruit curd, fruit juice, ice-cream, pudding and jam/marmalade.

By-product of banana cultivation:

• The leaves are partly used as packaging and mulch material, for roofing or as feed.

Gene technology: aims in research and development

Agronomic traits

Disease resistance

• Fungal resistance: with gene technological concepts, a resistance to the Black Sigatoka and Fusarium wilt has been produced in the banana. These fungae are pathogenic agents of the two most important banana diseases. With conventional breeding resources, an improved resistance is only achieved with great difficulty.

• Viral resistance: to the Banana Bunchy Top Virus or the Banana Bract Mosaik Virus.

• Bacterial resistance: in Uganda research is being done with gene technological modified bananas that show a resistance to Xanthomonas campestris. The bacterium activates a leaf wilt and causes profit cuts of up to 90 per cent.

Resistance against pests

• Resistance to nematoden: for this purpose, cystatin genes are inserted into bananas. Cystatin inhibits active agents that nematodes produce in order to penetrate into the banana stalk. Thus, it prevents oviposition.

Quality traits

Enrichment with health promoting ingredients

• In Australia, a GM banana with increased content of vitamin E, pro vitamin A and iron has been developed.

Plant development

• Modified ethylene production and maturation deferment

Renewable resources

Production of pharmaceutical ingredients

• Molecular pharming: vaccine bananas are expected to be used for the production of vaccines. For that purpose, DNA sequences of specific disease proteins are channelled into the banana genome. By consuming these bananas, the immune system builds antibodies to the pathogen proteins and accrues protection by vaccination. Research for vaccine bananas against hepatitis B, jaundice, cholera, polio, rubella/measles and diarrhoea is being done. These bananas are expected to be introduced in countries in which classical vaccine campaigns are only performed with difficulty.

Field trials with GM bananas