WASHINGTON, D.C., U.S. — U.S. Department of Agriculture (USDA) scientists as part of an international team have completed a “shotgun sequencing” of the wheat genome for the first time, according to a paper published Nov. 28 in the journal Nature.
Wheat was the main remaining field crop that had not been genetically sequenced by scientists, and the breakthrough spurred ideas that yields may increase and more nutritious wheat will be bred as a result.
Olin Anderson and Yong Gu, scientists with USDA's Agricultural Research Service (ARS) based at the agency's Western Regional Research Center in Albany, California, U.S., played instrumental roles in the sequencing effort, along with Naxin Huo, a post-doctoral researcher working in Gu's laboratory.
“By unlocking the genetic secrets of wheat, this study and others like it give us the molecular tools necessary to improve wheat traits and allow our farmers to produce yields sufficient to feed growing populations in the United States and overseas,” said Catherine Woteki, USDA’s chief scientist and Undersecretary for research, education and economics. “Genetics provides us with important methods that not only increase yields but also address the ever-changing threats agriculture faces from natural pests, crop diseases and changing climates.”
Wheat is grown on more land than any other commercial crop and is the world’s most important staple food.
“It’s improvement has vast implications for global food security,” the USDA said. “The study represents the most detailed examination to date of the DNA that makes up the wheat genome, a crop domesticated thousands of years ago. The wheat genome is five times the size of the human genome, giving it a complexity that makes it difficult to study. The researchers used the whole genome shotgun sequencing approach, which essentially breaks up the genome into smaller, more workable segments for analysis and then pieces them together.”
The USDA has conducted similar genomic studies on other crops such as tomatoes, corn and soybeans.
Another international team of scientists is working on a long-term project expected to result in more detailed sequencing results of the wheat genome in the years ahead. But the published results shed light on wheat's DNA in a way that will help breeders develop hardier varieties by linking genes to key traits, such as disease resistance and drought tolerance.
Wheat evolved from three ancient grasses, and the ARS team, working closely with partners at University of California, Davis, sequenced the genome of one of those three parents, Aegilops tauschii. That sequencing, funded in part by the National Science Foundation, was instrumental in the study. It allowed researchers to identify the origins of many of the genes found in modern-day wheat, a key step in linking genes to traits and developing markers for use in breeding new varieties.