Two oat genotypes identified by Agricultural Research Service scientists and cooperators were found to be more freeze-tolerant under controlled field tests than any variety released during the past 65 years.
Plant physiologist David P. Livingston, with the ARS Plant Science Research Laboratory, and plant breeder Paul Murphy at North Carolina State University--both in Raleigh, N.C.--reported the findings in the journal Crop Science.
Among fall-sown grain crops, oats are much less winter hardy than wheat, barley and rye. Sustained temperatures at or below 20 degrees Fahrenheit usually result in yield losses.
The scientists screened lines produced from the cross of two historic U.S. winter oats: Wintok, released in 1940, and Norline, released in 1960.
Starting with 10,000 plants from the two varieties, the researchers used progressively lower temperatures to screen for the toughest lines. Two of the new lines, WN1 and WN10, were more winter-hardy than either of the two hardy cultivars from which they were crossed. Despite their superior freezing tolerance, neither germplasm was late-flowering, a trait commonly linked to freeze tolerance.
The scientists suspect that each of the parent cultivars possessed different alleles for freezing tolerance, and that those alleles were combined into a single genotype. Alleles are natural variations of a particular gene among members of the same species.
These germplasm lines have alleles that allow regenerative cells within the plant crown to sufficiently resist ice and cold. The crown is the area where a plant's root and stem meet, and it contains various compounds that are critical to the plant's regrowth after winter.
Increased winter hardiness among oat varieties could allow farmers as far north as Pennsylvania and Ohio to grow winter oats in the future. The germplasm is being used by breeders to cross with high-yielding, disease-resistant varieties.
ARS is the U.S. Department of Agriculture's chief scientific research agency.