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NEWS RELEASE: Confirmation of new races of yellow and brown rust

22 August 2011


The UK Cereal Pathogen Virulence Survey (UKCPVS) confirms the presence of new races of yellow rust and brown rust in winter wheat.

Yellow rust (Puccinia striiformis) samples collected from three farm crops of Warrior winter wheat earlier this summer have re-infected the variety in the first round of testing by the UKCPVS at NIAB TAG. 

“Warrior had previously been resistant to all yellow rust disease isolates at seedling and adult plant stages.  The new isolates have now been shown to infect the seedlings of the variety, which is evidence that we are dealing with a new race,” explains Dr Rosemary Bayles, principal cereal pathologist at NIAB TAG.

Warrior currently has a rating of 9 for both yellow rust and brown rust resistance on the HGCA 2011/12 Recommended List.

The variety has also been shown to be susceptible to the new race of brown rust (Puccinia triticina) recently identified on the winter wheat variety Stigg.  Tests by UKCPVS demonstrated that a brown rust isolate collected from a field plot of Stigg was able to infect Warrior, while another isolate collected from a plot of Warrior infected Stigg.  “This verifies the presence of a new brown rust race able to overcome the resistance of both varieties,” says Dr Bayles.

Initial testing has so far focused on varieties that were considered to have the highest disease resistance rating.  The next step will be to discover which other winter wheat varieties may be vulnerable to the new races of yellow rust and/or brown rust, including field tests next season.

 ENDS

Notes for editors

The UK Cereal Pathogen Virulence Survey (UKCPVS) is funded by Fera and HGCA and managed by NIAB TAG.  It has been monitoring cereal rusts and mildews in the UK for more than 40 years, detecting and warning industry and growers of new races of disease emerging on resistant varieties.  The UKCPVS:

  • Monitors changes in virulence of UK cereal pathogen populations
  • Maintains and improves variety disease resistance allowing growers to prioritise other characteristics such as yield and quality when choosing a variety
  • Enables breeders and variety testing authorities to screen out potential new varieties and breeding lines that are too susceptible to new races of disease before they get to the HGCA Recommended List stage or onto farm
  • Provides information and warnings to assist disease risk management on farm; underpinning HGCA RL disease resistance ratings and assessing the threat that each new race poses to the full range of commercial varieties.

 

For further information contact:

Dr Rosemary Bayles, NIAB TAG
T:            01223 342211
E:            rosemary.bayles@niab.com

Dr Kerry Maguire, NIAB TAG
T:            01223 342213
E:            kerry.maguire@niab.com