Student - September 28, 2006

Dangerous fusarium fungi on the rise

Since the discovery that the infection of crops with some fusarium fungi strains can lead to an accumulation of toxins in food and animal feed, the interest in this fungus has spread like wildfire. Plant Research International has now developed a clever test that can rapidly detect dangerous fusarium strains

‘Fusarium already had a bad name among Dutch farmers, because the fungus can cause considerable yield losses in crops such as tomatoes, cucumbers and ornamentals,’ says PRI researcher Dr Cees Waalwijk, chairman of the ninth European Fusarium Seminar, which was held in Wageningen last week. ‘That the fungus can also produce natural toxins, mycotoxins, which accumulate easily in food, has only recently started to receive attention. But as we are being inundated with all sorts of food safety legislation from Brussels, fusarium is now in the limelight.’

According to Waalwijk, fusarium is set to become one of the top three most important plant diseases. This is because many wheat and maize varieties are susceptible to the four most common mycotoxin-producing fusarium strains. Infection with this kind of fungus not only leads to yield losses, but also poses a big health risk, as wheat and maize are key ingredients for many food products and animal feed.

In order to detect the presence of dangerous fusarium strains, Waalwijk’s research team has now developed an elegant and rapid test based on the TaqMan PCR-technology. ‘The name TaqMan takes its inspiration from the computer game PacMan. In the test, if fusarium is present, characteristic molecules are ‘eaten up’ and when a certain quantity have been detected, a fluorescent signal is emitted. It is a quantitative test that not only determines what type of fungus has infected a plant or grain shipment, but also how serious the infection is,’ explains Waalwijk.

The test is not yet ready to be marketed, but has been used in recent years to carry out a survey of the types of mycotoxin-producing fusarium strains that are present in Dutch wheat. Waalwijk: ‘In the field we are noticing a shift towards more aggressive fungus types. This is not good news.’