USDA scientists sequence the wheat genome

November 29, 2012

A study published in Nature shows that U.S. Dept. of Agriculture (USDA) scientists working as part of an international team have completed a shotgun sequencing of the wheat genome. The achievement is expected to increase wheat yields, help feed the world, and speed up development of wheat varieties with enhanced nutritional value.

“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 Under Secretary 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.”

Grown on more land area than any other commercial crop, wheat is the world’s most important staple food, and its improvement has vast implications for global food security. The work to complete the shotgun sequencing of the wheat genome will help to improve programs on breeding and adaptation in Asia and Sub-Saharan Africa for wheat crops that could be drought tolerant and resistant to weeds, pests, and diseases.

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.

Wheat evolved from three ancient grasses, and the scientists 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.

USDA press release