Western Europe has seen small disease outbreaks of wheat stem rust recently and which has led to the industry being advised to work together to develop the knowledge and tools required to keep this crop pathogen at bay.
A single infected wheat plant was also discovered in the UK, at a site in Suffolk, in 2013. Although an isolated case, it is the first known example of the disease in the UK in over 60 years.
Following genetic tests, led by Diane Saunders and Brande Wulff at the John Innes Centre, it was discovered that the UK strain belongs to the Digalu race of the fungus. In 2013, this same strain caused small outbreaks in Sweden, Denmark and Germany, as well as major outbreaks in Ethiopia. Major outbreaks occur in higher-temperature climates, which favour the pathogen.
Although unlikely to be an immediate threat to UK production, predicted changes to the UK climate could make the conditions more conducive to the disease, particularly warmer temperatures.
The pathogen has not been a focus of breeding programmes in recent years. In fact, over 80 per cent of UK wheat varieties tested are susceptible to this strain, according to results from Jane Thomas at the National Institute of Agricultural Botany. European wheat varieties also lack resistance genes. The good news is that scientists and plant breeders are now working together on genetic solutions, although such solutions will probably take a considerable amount of time to reach commercial wheat varieties.
As wheat stem rust is closely related to wheat yellow and brown rusts (all Puccinia species), however, fungicides used in the UK, such as azoles, should control the disease, in case the disease returns to our shores. But, as with all disease challenges, genetic control is the ultimate goal.