Published online 1 October 2010 | Nature | doi:10.1038/news.2010.509


Uganda prepares to plant transgenic bananas

Sweet pepper gene confers resistance to bacterial wilt.

Banana plants growing at Uganda's National Agricultural Research Institute, KawandaBanana plants growing at Uganda's National Agricultural Research Institute. Field trials of a GM variety are set to begin next week.Linda Nordling

Scientists in Uganda will next week start field trials of a banana variety genetically engineered to resist a bacterial disease that has been decimating crops across central Africa.

The new variety is part of a wider effort to improve the East African Highland banana, a fruit so important to Ugandans that its name, matooke, is synonymous with 'food' in one of the local languages. But delays to a law regulating the commercial growing of genetically modified (GM) food in the country means it is not clear when the improved banana could be released to farmers.

The bananas have a gene from green pepper to protect against banana Xanthomonas wilt (BXW), which costs farmers in Africa's Great Lakes region an estimated half a billion dollars every year. Bananas infected with BXW ripen unevenly and prematurely, and eventually the entire plant wilts and rots. The disease was originally found in Ethiopia, but was discovered in Uganda in 2001 and has rapidly spread to the Democratic Republic of Congo, Rwanda, Kenya, Tanzania and Burundi.

The sweet pepper gene produces a protein called HRAP that strengthens the plant's ability to seal off infected cells. The idea was pioneered by scientists at the Academia Sinica in Taiwan, where it has been shown to improve the disease resistance of vegetables including as broccoli, tomatoes and potatoes.

Banana plants growing at Uganda's National Agricultural Research Institute, KawandaGM crops remain controversial in Uganda.Linda Nordling

The Ugandan research team, based at the National Agricultural Research Laboratories in Kawanda, received a royalty-free licence to use the technology in 2006.

Six of the eight GM banana strains developed with the green pepper gene showed 100% resistance to BXW in the lab1.

"This is the first time this gene has been used in Africa, and it is the first time the technology is going to be tested in the field," says Leena Tripathi, a biotechnologist from the International Institute of Tropical Agriculture in Kampala, and lead investigator of the Ugandan project.

The field trials will also screen GM banana varieties with resistance to BXW for resistance to fungal diseases and analyse whether the breed affects the composition of microorganisms in the soil. These plants will grow side by side with another GM banana variety developed at the laboratory, which has been fortified with vitamin A and iron to help to combat blindness and anaemia in rural areas.

Legal roadblock

But the future of Uganda's biotechnology advances remains uncertain. Scientifically, Uganda is one of Africa's leaders in developing GM varieties of local staples. But its government has yet to pass a law to regulate the commercial release of GM organisms.

"Uganda is doing very well with the resources that it has at the moment," says Felix M'mboyi, executive director of the African Biotechnology Stakeholders Forum, which is based in Nairobi. "They have built their own local capacity, especially doing research on their own variety of banana."

Map of some GM trials in AfricaClick for a larger version of this map.

Three African countries — South Africa, Egypt and Burkina Faso — are growing GM crops commercially, and Kenya expects to start doing so in 2012. Several others are hosting field trials or are about to start hosting them (see map, left). Many will focus on local staples such as cowpea (or black-eyed pea), cassava and sweet potato.

Uganda's biosafety law has been stuck in the country's legislative system for years. A draft law exists, based on a biotechnology and biosafety policy adopted in 2008, that would allow controlled commercial releases of GM crops.

But with general elections expected to be held in February next year, MPs will be too busy focusing on re-election to have time to debate the law before then. Although political resistance to the introduction of GM food has softened in recent years, several MPs remain sceptical. And once the new parliament has been elected, resistance could grow once more, says M'mboyi.


Urban Ugandans are more opposed to GM crops than their rural counterparts are, according to a PhD thesis published earlier this year2.

But many city dwellers change their tune when they realise that they may unwittingly have eaten GM maize, for example, in breakfast cereals imported from South Africa, says Wilberforce Tushemereirwe, who heads the country's National Banana Research Programme. "Every time you tell them that, they say 'Oh, is that it?'" he says. He says that the current delays are a temporary setback. "There will be a law in one to two years time."

But the situation is not satisfactory for the country's researchers, concedes Maxwell Otim, deputy executive secretary of the Uganda National Council for Science and Technology, which coordinates the country's interim biosafety regulations. "There is an anxiety, which must be alleviated," he says. 

  • References

    1. Tripathi, L., Mwaka, H., Tripathi, J. N. & Tushemereirwe, W. K. Molecular Plant Pathol. 11, 721-731 (2010).
    2. Kikulwe, E. M. On the Introduction of Genetically Modified Bananas in Uganda: Social Benefits, Costs and Consumer Preferences. PhD thesis, Wageningen Univ. (2010).
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