UK - Studies of cereal pathogen populations in the UK have shown rusts are becoming increasingly diverse – affecting varieties in different, and often unpredictable, ways – and crops should be monitored closely.
This was a key message arising from today’s UK Cereals Pathogen Virulence Survey (UKCPVS) stakeholder event in Cambridgeshire.
Managed by NIAB, and funded by HGCA and Fera, UKCPVS receives infected cereal leaf samples from agronomists, trials officers and researchers.
From these samples, pathogen isolates are selected and tested to check their virulence against wheat and barley varieties.
The testing can detect new races of cereal pathogens capable of causing disease on previously resistant cereal varieties.
Targeted at breeders, crop scientists and technical agronomists, the event reported on recent seedling test results (using samples received during 2014) and adult plant nursery tests (using samples received during 2013).
Yellow rust: latest results from UKCPVS
The samples received by UKCPVS in 2014 were dominated by Warrior-type isolates (25 of the 27 tested to date). This mirrors the trend of the past few years.
By testing pathogen virulence on varieties with known resistance genes, four distinct groups within the Warrior-type race have been characterised (Warrior 1–4) and the rise and fall of each group within the UK population has been monitored.
Dr Sarah Holdgate, UKCPVS project manager based at NIAB, said: “When it was originally detected in 2011, Warrior 1 was dominant but since then it has declined, with Warrior 3 increasing in frequency.
“In addition to the number of Warrior groups currently identified in the UK, our work also shows the groups themselves carry a diverse range of virulence genes – meaning they can infect wheat crops to varying degrees.
“In fact, some of the latest isolates have presented the UKCPVS with a challenge in how to name the races – there are now Warrior races which fail to cause disease on the variety Warrior.
“We are looking at a new naming approach and isolates which we call the Warrior types could have a new name later in the year.”
Both Warrior-type and Solstice-type isolates from 2013 were used in adult plant tests.
Encouragingly, 20 out of 41 of the current Recommended List varieties were resistant to all isolates tested.
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TheCropSite News Desk