13 March 1998

Faster detection for spud virus

SCIENTISTS have developed a virus detection system that could give seed potato producers more control over the management of their crops.

The technique, which determines the levels of potato virus Y infection in the growing seed crop, could be available in two years.

"We are aiming towards much faster tests for indexing tubers, and now we can do it in just one day," says Dr Ian Barker of MAFFs Central Science Laboratory in York.

Current indexing techniques can currently take up to eight weeks. The new test, known as Taq-Man, uses the so-called polymerase chain reaction to detect low virus levels in infected tubers, so avoiding the need to grow cuttings.

Six-second sample

A new machine, the ABI PRISM 7200 Sequence Detection System, scans 96 samples in six seconds.

For the farmer, the fast turn-round will allow decisions on seed potatoes to be taken more quickly. Expensive storage costs could be avoided if it is known beforehand that virus incidence in a crop means it will fail to achieve certification, says Dr Barker.

Growers need to be certain that the test is as reliable as current methods, and not too expensive, notes Jenny Vaughan, from NIABs virus indexing service.

According to Dr Barker costs will be similar to the current £110 per 100 tuber sample. "We expect the new assay to be available within one or two years," he concludes.

Virus-infected spud seed can be spotted in a day, say CSLscientists Ian Barker (left) and Neil Boonham.