28 March 1997

Disease resistant spuds just around the corner

In the latest of our Biotech Monitor series of articles we bring you up to date on plans to add virus tolerance to potatoes and prevent pests overcoming insect resistance genes in a range of crops

POTATOES with genetically modified resistance to virus diseases should be available to UK growers early next decade, delegates heard at a biotechnology seminar held last week at the Royal Agricultural College.

"Developing resistance to viruses has been a major challenge," said David Fishchoff, Monsantos director of modified crops in St Louis, USA. "Unlike other pests there is no direct control agent."

However, research has exposed a weak link which genetic engineering can exploit. The result is very high levels of resistance to a specific virus. Potato plants resistant to potato X, Y and leaf roll virus have been developed, leading to higher yields and better quality tubers (see story left/right).

Work has focused on potatoes because they are vegetatively propagated, so a high degree of virus disease control is needed to prevent a rapid spread of infection, said Dr Fishchoff.

Most of the work has concentrated on Russet Burbank, which accounts for about half the USAs potato area. "In Europe, the situation is more tricky because of the greater number of varieties." But an agreement with seed companies could speed the introduction of the trait, he believed.

Genetic engineering to prevent pests, viruses and diseases carrying off potato profits are now a reality. Colarado beetle is just the first target.

GM crops can offer growers big savings, according to Monsanto. Cotton growers typically spend $50-$100/acre on insecticides and still suffer some yield loss. But farmers growing Bollgard spent just $32 extra on seed for a technology fee and suffered less loss, it claims.