Annual Progress Report on Malting Barley Research March, 2007

owed, spring, barley germplasm lines in 2-rowed, malting barley backgrounds were
released in 2006. Breeders should be able to utilize these germplasm lines directly in a
breeding program with reduced detrimental affect on malting quality as well as grain
yield. Seven, RWA-resistant, 2-rowed, spring, feed barley germplasm lines were also
released in 2006. There are 34 different sources of resistance involved in these 50
germplasm lines. All 43 spring germplasm releases were tested against 5 biotypes of
RWA in 2006. Resistance appears to be holding up to all biotypes. Analysis is ongoing.
Stoneham and Sidney, drought hardy, spring, 2-rowed, feed barley cultivars were also
released in 2006. These barleys are not only RWA-resistant but also adapted to the
high and dry production areas of eastern Colorado and Wyoming and western Nebraska
and Kansas.
Objectives, Methodology, and results
The prebreeding program is designed to bring resistance genes from unadapted
germplasm lines into adapted malting and feed barley backgrounds for all barley
growing regions in the U.S. It involves repeated backcrossing with intermittent
screening with a time commitment of approximately seven years from the first cross
until homozygous resistant BC3F3 lines can first be evaluated as observation lines in
the field. This is an ongoing process involving many resistant lines and adapted
cultivars currently in all phases of the program. Field testing is ongoing in cooperation
with Phil Bregitzer (spring barley) and Don Obert (winter barley) scientists with the
USDA-ARS in Aberdeen, Idaho; Frank Peairs, Colorado State University; and Gary
Hein, University of Nebraska.
The first RWA-resistant barley cultivar, Burton, was selected and released to breeders
in 2004 cooperatively by ARS in Aberdeen and Stillwater, Colorado State University,
University of Nebraska and New Mexico State University. In the summer of 2005,
foundation seed was grown in Colorado and Nebraska for two new RWA resistant,
drought-hardy, spring feed barley cultivars Stoneham and Sidney. These cultivars were
co-released by USDA-ARS in Stillwater, USDA-ARS in Aberdeen, Colorado State
University and University of Nebraska in 2006. Both are in an Otis background with
resistance from STARS 9301B (Sidney) and STARS 9577B (Stoneham). The need for
genetic diversity is very important and has been demonstrated since the 2005 growing
season with severe yield losses of RWA resistant winter wheat by a new virulent
biotype(s) of RWA in Colorado and Nebraska. A survey of biotypes in Wyoming,
Colorado, Nebraska, Kansas, Oklahoma, Texas, and New Mexico in 2006 by Gary
Puterka, USDA-ARS, Stillwater, has shown RWA2 to be the predominant biotype of
RWA in all these states except New Mexico, where RWA1 still predominates. Both
Sidney and Stoneham are highly resistant to all known biotypes of RWA and out yielded
Otis in 12 large-scale on farm tests conducted in 2006 by cooperators Frank Peairs and
98