Germplasm
Enhancement for RWA Resistance
D.W. Mornhinweg and D.R. Porter
USDA-ARS Wheat, Peanut and Other
Field Crops Research Unit
Prebreeding for adapted germplasm
lines (RWA 1)
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
Seven,
RWA-resistant winter feed barley germplasm lines (STARS 0501B STARS 0507B)
were released in 2005. These lines
involved 7 different sources of resistance each in a Schuyler background. In 2006, 43 RWA-resistant spring germplasm
lines were released. STARS 0601B STARS
0619B involved 19 different sources of resistance in 4, spring, 6-rowed,malting
barely backgrounds - Excel, Morex,
Robust and Stander. STARS 0620B STARS
0636B involved 17 different sources of resistance in 4, spring, 2-rowed,
malting barley backgrounds B1202, Crest, Crystal, and Harrington. STARS 0637B STARS 0643B involved 5
different sources of resistance in 3, spring, 2-rowed, feed barley backgrounds
Bowman, Hector, and Otis. The 2006
spring germplasm releases involved 31 different sources of RWA resistance and
the winter germplasm lines another 5 sources.
The determination of the number of different genes in these 36 lines is
underway.
Another
9 winter barley lines have been selected from preliminary yield trials in
cooperation with Don Obert, USDA-ARS,
Several
spring and winter barleys from the prebreeding program are in elite field
trials of Phil Bregitzer and Don Obert, USDA-ARS,
RWA Biotypes
In
2003, a new biotype of RWA (RWA2) was identified on previously RWA-resistant
wheat cultivars in
Genetic Studies
RWA
Complete
genetic analysis, using RWA 1, has been performed on 11 out of a total of 109
RWA 1-resistant lines developed by the USDA-ARS in
Genetic
diversity studies are also planned for all resistant lines to determine if
these lines carry different genes for resistance to RWA1. Multiple allelism testing requires 3 years
for development of seed necessary for each test. The first test for multiple allelism was preformed
in the winter of 2004 for STARS-9301B and STARS-9577B. Inheritance studies for each line indicated 2
genes control RWA resistance in each line.
Parents, F1 (STARS 9301B/STARS 9577B), reciprocal F1, F2, TC1F2, and
TC1F1:F2 families were screened with RWA1.
Multiple allelism analysis indicates 4 distinct genes (or alleles).
Lynn Dahleen, USDA-ARS Fargo, ND, is
cooperating to map the genes for resistance in these 2 lines. As a part of that project, each line was
crossed as a male to Morex and 300 F2:F3 families from each population were
grown and phenotyped for RWA1 resistance.
Remnant seed was sent to
Greenbug
Genetic populations continue to be developed to determine
the inheritance of greenbug biotype G resistance in three lines, Wintermalt,
Bancroft and Colter.
Post 90 winter barley has Rsg1 resistance. The source of Rsg2
resistance in barley is PI 426756.
This accession is heterozygous for greenbug resistance. Progeny from resistant selections out of PI
426756 were screened to greenbug biotype E and seedlings from homozygous
resistant plants rescued, increased, and bulked in the greenhouse. This homozygous source of Rsg2 resistance was designated
GB02. GB02 is a 6-rowed spring
barley. GB02 was crossed as a male to
Weskan to develop winter barley with Rsg2
resistance.
Twenty-nine hulless winter barley accessions
from the NSGC were identified with resistance to greenbug biotype E. In the spring of 2007, these 29 lines plus
the barley differentials, Post 90, GB01, and Wintermalt, were tested against 12
biotypes of greenbug in cooperation with John Burd, research entomologist,
USDA-ARS,
Cooperative screening
Four hundred and twenty one accessions were screened to RWA1
and greenbug for the National Small Grains Collection. 189 advanced lines were screened to RWA1 for
Phil Bregitzer, USDA-ARS,
Bird Cherry oat aphid
BCOA damage to barley seedlings is
morphologically symptom-less. As a
result, traditional seedling screening techniques are not successful in identifying
BCOA resistant barleys. Development of a
greenhouse seedling screening test would make screening of large barley collections
fast and effective for identification of BCOA-resistant barleys. A new seedling
screening technique has been developed in
There
is new interest in winter hulless barley in
Germplasm
Enhancement
Dolores W. Mornhinweg, Geneticist
David R. Porter, Research Geneticist
Cooperators
Don Obert, Research Geneticist,
USDA-ARS,
Phil Bregitzer, Research Geneticist,
USDA-ARS,
Frank Piears, Professor,
Bob Hammond, Professor,
Dave Baltensperger, Professor,
Gary Hein, Professor,
Lynn Dahleen, Research Geneticist,
USDA-ARS,
Gary Puterka, Research Entomologist,
USDA-ARS,
John Burd, Research Entomologist,
USDA-ARS,
Bregitzer, P, D.W. Mornhinweg, and B.L.
Jones. 2003. Resistance to Russian Wheat
Aphid Damage Derived from STARS-9301B Protects Agronomic Performance and
Malting Quality When Transferred to Adapted Barley Germplasm. Crop Sci. 43:
2050 2057.
Bregitzer, P., D.W. Mornhinweg, R.
Hammon, M. Stack, D.D. Baltensperger, G.L. Hein, M.K. ONeill, J.C. Whitmore,
and D.J. Fiedler. 2005. Registration of
Mornhinweg, D.W., L.H. Edwards, E.L.
Smith, G.H. Morgan, B.F. Carver, J.A. Webster, and D.R. Porter. 2004. Registration
of Post 90 Barley. Crop Sci. 44: 2263.
Porter, D.R., and D.W. Mornhinweg. 2004.
New sources of Greenbug Resistance in Barley.
Crop Sci. 44: 1245-1247.
Porter,
D.R., and D.W. Mornhinweg. 2004.
Characterization of greenbug resistance in barley. Plant Breeding 23(5): 493-494.
Mornhinweg, D.W.,
M.J. Brewer, and D.R. Porter. 2006. Effect of Russian wheat aphid on yield and
yield components of field grown susceptible and resistant spring barley. Crop Sci 46:36-42.
Mornhinweg, D.W.,
D.E. Obert, D.M.