United Kingdom
May 5, 2009
The
National Institute of Agricultural Botany (NIAB) is
investigating a potential new race of yellow rust on winter
wheat.
In 2008 the United Kingdom Cereal Pathogen Virulence Survey
(UKCPVS) collected two isolates of yellow rust from Group 1
wheat Solstice and confirmed that they were virulent on
seedlings of the variety. Solstice currently has a resistance
rating of 9 and, until last season, was resistant to all known
races of yellow rust.
NIAB is now testing the isolates on adult plants in the field to
determine the level of susceptibility of Solstice and other
varieties to the yellow rust race.
Wheat growers also face a resurgence of older races of yellow
rust. NIAB’s Dr Rosemary Bayles attributes this to an increasing
area of varieties with the yellow rust resistance gene Yr6.
“Despite predictions that yellow rust was unlikely to be a
problem because of the cold winter, outbreaks of the disease
have already been detected in wheat crops particularly in the
high risk areas of the East Midlands and East Anglia. Reports
suggest that Robigus and Oakley are particularly affected at
present,” says Dr Bayles.
Robigus, with a rating of 2, is extremely susceptible to a
specific race that has dominated the yellow rust population for
several years now. However, Oakley has remained largely free to
date, so the more widespread appearance of the disease in crops
has perhaps come as more of a surprise to growers.
UKCPVS results show that Oakley, with a rating of 6, is
moderately susceptible to a separate race of yellow rust, which,
although once quite common, has become less frequent in recent
years. Unlike the common ‘Robigus race’ the types that infect
Oakley carry virulence for the resistance gene Yr6. These are
the races that infected older varieties including Madrigal,
Access and Napier as well as more recent ones such as Mascot and
Einstein.
“Our experience shows that as a variety becomes more widely
grown on farms, yellow rust races with corresponding virulence,
capable of infecting the particular variety, rapidly become more
common. We would therefore expect to see an increase in
Yr6-virulent races of yellow rust in response to the increasing
acreage of Oakley – and this would account for the increased
incidence of the disease in this variety,” says Dr Bayles.
The National Institute of Agricultural Botany (NIAB) is a
pioneering plant science organisation based at the heart of the
Cambridge science, technology and university communities and a
thriving UK agricultural industry. It has an internationally
recognised reputation for independence, innovation and
integrity. Founded in 1919, NIAB has over 90 years experience in
the agricultural and food sectors. The Institute employs 161
staff with the main headquarters in Cambridge and regional
offices at Headley Hall in North Yorkshire, Harper Adams in
Shropshire, Seale Hayne in Devon, Boston in Lincolnshire,
Monkhall in Hereford, Itchen Stoke in Hampshire and Wye in Kent. |
|
