• 15 May 2006
• From New Scientist Print Edition. Subscribe and get 4 free issues.

WITH the future of bananas in the balance (see "A future without bananas?"), there's more worrying news for another major food resource. Maize, the world's most widely grown crop, is facing its own genetic meltdown

The world's crop gene banks are in crisis, a meeting of maize researchers and organisations in Texcoco, Mexico, was told last week. At least half the seed stocks are unable to germinate because of incorrect storage, with potentially dire consequences for the world's food supply.

Maize - known as corn in North America - grows in 160 countries, but to maintain its high productivity and keep a genetic edge over weeds, pests and diseases requires constant interbreeding between varieties. Most of the genes needed for this breeding now come from the freezers of gene banks, held by governments and international centres, which between them have more than 250,000 varieties of maize.

Unfortunately much of the stock is useless, says Cary Fowler of the Global Crop Diversity Trust in Rome, Italy. "Germination rates are falling quite dramatically, and genes and genetic traits are being lost as a result," he says.

Suketoshi Taba, head of CIMMYT, the international maize gene bank based in Mexico, says fewer than half the maize seeds held in store round the world were able to germinate. Many had not been dried properly before being put into storage. Others were lost when refrigeration units failed during power outages.