Common wheat has one of the largest genomes among crops, and is nearly three times the size of the human genome.
Researchers used a method called whole genome shotgun sequencing that involves random bits and pieces of DNA that leaves many gaps in the sequence and is not anchored to a map.
While the reported shotgun sequence of the wheat is useful, a team of sciences at the International Wheat Genome Sequencing Consortium, or IWGSC, is working to produce a gold standard sequence of the wheat genome. The gold standard will be the complete sequence anchored to a genetic map of agronomic traits that are important to the wheat industry.
The consortium scientists are using special genetic stocks provided by the university's Wheat Genetics Resource Center, which were sent to many institutes around the world for physical mapping and sequencing of the 21 chromosomes of wheat. The center was responsible for gold standard mapping and sequencing of four of the 21 chromosomes.
"The polyploidy is both a curse and a blessing," Gill said. "It provided the evolutionary novelty that made wheat the world's most important crop, but at the same time it made the genome more complex and a hard nut to crack."
Shotgun sequencing revealed that the plant has roughly 100,000 genes compared to the 30,000 genes in humans. The gene sequences were used to identify, categorize and record the potential functions of thousands of individual genes and gene cluster locations -- creating a rough map with points of interest for future studies.
"With funding from the United State Department of Agriculture and the National Science Foundation, center scientists have made sequence-ready physical maps of the four wheat chromosomes assigned to the U.S., but lack of funding is hurting the U.S. effort for gold standard sequencing of the wheat genome," Gill said.