Kansas State University researchers have assisted in the development of a genetic blueprint for common wheat, a crop grown on more than 531 million acres around the world.
The International Wheat Genome Sequencing Consortium, which also includes faculty at Kansas State University, recently published a chromosome-based draft sequence of wheat's genetic code, called a genome.
The genetic blueprint will be a resource to plant science researchers and breeders, said Eduard Akhunov, associate professor of plant pathology and a collaborator with the IWGSC.
"For the first time, they have at their disposal a set of tools enabling them to rapidly locate specific genes on individual wheat chromosomes throughout the genome," Akhunov said. "This resource is invaluable for identifying those genes that control complex traits, such as yield, grain quality, disease, pest resistance and abiotic stress tolerance."
Akhunov said researchers will be able to produce a new generation of wheat varieties with higher yields and improved sustainability with the data.
Although a draft, the sequence provides new insight into the plant's structure, organization, evolution and genetic complexity – information that can provide a foundation for understanding how changes in the genetic code can impact important agronomic traits.
In Akhunov's lab, the sequence is used to get insights into the evolution and origin of wheat genetic diversity.
This study is one of four papers about the wheat genome that appear in the journal Science. A second study details the first reference sequence of chromosome 3B, the largest chromosome in common wheat.
"The wheat genome only has 21 chromosomes, but each chromosome is very big and therefore quite complicated," Akhunov said. "The largest chromosome, 3B, has nearly 800 million letters in its genetic code. This is nearly three times more information than is in the entire rice genome. So trying to sequence this chromosome — and this genome — end-to-end is an extremely complicated task."
To analyze the vast amount of genetic information, researchers used a technique called shotgun sequencing. This divided the wheat genome into chromosomes and then split each chromosome into smaller segments. Chromosomal segments were analyzed by short gene sequences and overlapping sequences were stitched together with computer software.
'Critical step' before full sequencing
The chromosome-based daft sequence the critical step before the full wheat genome is sequenced, Akhunov said. The sequencing approach developed for the 3B chromosome can now be applied for sequencing the remaining chromosomes in wheat.
The consortium estimates the full genome sequence will be available in three years.
The research is funded by the U.S. Department of Agriculture's National Institute of Food and Agriculture.