Scientists from the U.S. Department of Agriculture's Agricultural
Research Service (ARS) are preparing wheatfor climate challengesahead.

The scientists are subjecting more than a dozen wheat varieties to two
major stressors. The first comes from exposure to carbon dioxide (CO2)
levels of up to 1,000 parts per millionā??an atmospheric concentration of
the greenhouse gas projected for the turn of the century absent
mitigation measures. The other stressor is infection by the insidious
fungus/Fusarium graminearum/. This fungus causes head blight, a costly
disease of wheat, barley, and oat crops worldwide that can damage the
grain and contaminate it with mycotoxins, rendering the grain unsafe for
food or feed use.

Initially, the scientists compared Alsen, a hard red spring wheat that
carries two commonly used genetic sources of blight resistance, to Norm,
a popular high-yielding but susceptible wheat variety. Alsen suffered a
greater loss in grain nutritional content than Norm, resulting in
increased mycotoxin production by certain Fusarium strains. In
subsequent experiments, the researchers observed similar responses in an
additional nine resistant and six susceptible varieties.

The team is also studying how the fungus itself behaves in wheat plants
exposed to high CO2 levels and observed that the severity of blight and
production of mycotoxins like deoxynivalenol depends on the fungal
strain and wheat variety attacked. They also found that besides protein
and minerals, Alsen plants suffered a drop in oleic and linoleic fatty
acids, which normally contribute to resistance to blight and other
fungal diseases.

Readying Wheat with Climate Resiliency : USDA ARS
[www.ars.usda.gov]