Harvesting-Trinity-wheat

Researchers believe selecting for shorter wheat varieties that also do not have awns may in part explain why UK wheat varieties have poor resistance against fusarium.

Armed with this knowledge, breeders can bring in new genetic material to result in better resistance that is comparable with varieties in other European countries.

See also: Wheat growers swing to varieties with better disease resistance

Paul Nicholson, crop genetics project leader at the John Innes Centre, says it stems from a semi-dwarfing gene that was introduced in the 1970s.

“It not only reduces plant height by interfering with signals from the plant to grow, but has an unexpected side-effect of altering the balance between resistance to different pathogens,” he explains.

While the introduction of the Rht2 dwarfing gene into UK varieties made them more vulnerable to fusarium, he believes it is a nearby gene that was introduced along with Rht2 that is responsible for much of the increase in susceptibility to fusarium.

The presence of awns also seem to be linked with fusarium resistance. He points to Niab Tag work with its Magic populations, combined with data from his own work, that shows awned lines being more resistant.

Therefore, Prof Nicholson believes the UK preference for shorter varieties and for those without awns may in part explain why today’s UK wheats are more susceptible.

“If you look at European varieties, they tend to be a bit taller, with awns,” he says.

The good news is that these European varieties could be the source of new material to bring resistance into newer varieties and this is something the breeders are doing.

This means there is the potential to reverse the susceptibility introduced into UK varieties many years ago, when fusarium was not such a widespread problem.