New Durum Wheat Line Resists Scab Disease
Suszkiw March 20, 2007
A new germplasm line of durum wheat, dubbed DGE-1, is now available
for geneticists and researchers to use in the fight against the fungus
Fusarium graminearum, which causes scab disease.
Scab, also known as Fusarium head blight, can substantially diminish
the grain yield and quality of durum, or "macaroni wheat," which is used to
make pasta and semolina. U.S. durum growers produced 101 million bushels of the
cereal crop in 2006.
Unchecked, the Fusarium fungus infects wheat heads, causing the
kernels to shrivel up and turn chalky white. It can also produce toxins which
reduce the market value and quality of the kernels.
Today's durum cultivars contain little or no scab resistance. However,
the wheatgrass Lophopyrum elongatum is almost immune to scab, notes
Jauhar, a research geneticist in the
River Valley Agricultural Research Center, operated by the Agricultural
Research Service (ARS) in Fargo, N.D.
DGE-1 has a pair of chromosomes from this wild grass that makes the
new wheat germplasm line scab-resistant.
Jauhar's studies have shown that the pair of grass chromosomes
carrying scab resistance became a stable part of DGE-1's genome, meaning that
the trait won't be lost when propagated from seed. Screening under greenhouse
and field conditions has shown an average 21 percent infection in DGE-1 heads,
compared to 80 percent in the durum cultivar Langdon. In field tests, DGE-1
plants grew to nearly 30 inches tall and matured one to two weeks later than
Langdon. Its seed was also slightly smaller but showed 100 percent
Released in January, DGE-1 isn't meant for direct use by farmers, but
rather by scientists conducting basic and applied research aimed at developing
new, scab-resistant durum cultivars. Plant geneticists, breeders and other
researchers engaged in similar work will find DGE-1 useful.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.