8 August 1997

Vine weevil resistant strawberries on track

GENETICALLY modified strawberries came through their first European field trial successfully earlier this summer. But are growers and consumers ready for such technology?

Scientists at the Scottish Crop Research Institute near Dundee used genetic material from the tropical cowpea to make strawberries resistant to vine weevil attack.

Growers certainly like the idea. "Definitely!" remarks Andrew Bain, a strawberry farmer from Invergowrie by Dundee. "We need something to help us cope."

Vine weevil is considered the number one pest of strawberries in the UK and temperate parts of Europe. It can cause yield losses of up to 80%, especially when crops are started under polythene.

Chemical or biological control is notoriously inefficient, and strawberry breeding lines have no natural sources of weevil resistance.

Inserting the CpTi cowpea gene results in the production of a protein which hits the weevils digestive system. Including it in the strawberry varieties Symphony and Melody has rendered both weevil resistant.

In general the publics reaction appears to have been minimal. Indeed a spokesperson for Asda says the supermarket chain is not against stocking genetically modified food, provided it is shown to be safe and there are benefits for the customers. Each case is checked on its own merits.

Trials on the modified strawberries will continue for several years while yield measurements and risk assessments are performed. There are also plans to fine-tune the genetic system so the CpTi protein is not present in the fruit – effectively making fruit from transformed and non-transformed strawberry plants identical.n