New lines of Great Northern beans,
such as those pictured here, have been released with resistance to key
New Rust- and Mosaic-Resistant Beans
Released By David
Elstein December 23, 2004
Six new germplasm lines of the Great Northern dry bean--the first
lines to have four resistance genes to a key rust pathogen--have been released
to the public by the Agricultural Research
Service (ARS), the Michigan Agricultural
Experiment Station and the University of Nebraska at
A. Pastor-Corrales of the ARS
Laboratory at Beltsville, Md., worked with his colleagues to breed
BelMiNeb-RMR-8, -9, -10, -11, -12 and -13. The germplasm lines are resistant to
all known strains of the rust pathogen Uromyces appendiculatus. What's
more, they have two additional genes that protect them against all strains of
two other organisms--bean common mosaic virus and bean common mosaic necrosis
The Great Northern bean is the fourth most important bean class in the
United States. These large, white beans are popular in baked bean dishes as
well as in soups.
To breed the resistant lines, the scientists used gene pyramiding, in
which more than one desirable gene is added to the plant. In this case, four
genes that are resistant to rust and two genes that are resistant to the
viruses were added through conventional breeding with molecular marker assisted
selection. There are many strains of the pathogens that cause the rust and
viral diseases. These strains may vary from one location and year to another.
By placing four rust and two mosaic resistance genes in the BelMiNeb beans,
there is a better chance that the bean will stay resistant to the rust and to
the two viral diseases.
Rust has severely reduced various dry bean yields during the past few
decades, and in some years has damaged half of the crop in certain locations.
Since the BelMiNeb beans are naturally resistant to rust and several viruses,
farmers will not have to use chemicals on the beans to control these diseases.
A limited quantity of seed is available by emailing Pastor-Corrales at
ARS is the U.S. Department of
Agriculture's chief scientific research agency.