An international team of researchers has mapped the wheat genome, a breakthrough that breeders say will make their work more efficient as they unlock the mysteries of which genes impact traits such as yield or resistance to disease.
More than 200 scientists from 73 research institutions in the International Wheat Genome Research Consortium published an article in the international journal Science including a detailed description of the complete bread wheat genome.
The genome is the complete set of an organism’s DNA — the building blocks that create all of its traits. Knowing the structure of the genome will help researchers understand which genes — or combinations of genes — express various traits.
“It’s all going to translate into better varieties for (farmers), and probably a little faster at getting new varieties out to them,” said Washington State University winter wheat breeder Arron Carter.
Breeders will be better able to understand which genes control the traits they’re looking to improve and include in new varieties, he said.
“We’ll understand yield potential better, because right now, yield is just kind of a black box,” Carter said. “I weigh the bag, and whichever bag weighs the most has the best yield, but I don’t know why.”
Understanding which genes impact yield will allow Carter to breed higher yielding wheat varieties.
Another example: Carter could release a variety today that has good resistance to stripe rust, but he doesn’t necessarily know which genes provide that resistance. With genome sequencing, breeders can identify different resistance genes and “pyramid” them together, Carter said.
The same goes for the genes involved in end-use quality, another black box.
“You make a cookie, and it’s a good cookie, but we don’t know all the reasons why it’s a good cookie,” Carter said. “All of these traits that are important to the grower, we’re going to start actually understanding the genes involved.”
It typically takes 7-8 years to breed a new wheat variety. Mapping the genome won’t necessarily speed up the process, but it will make it more efficient, Carter said. Breeders will still need to evaluate varieties in the field to be sure they’re performing as expected.
Carter and WSU spring wheat breeder Mike Pumphrey said they will work closely with WSU “cyber breeder” Zhiwu Zhang, assistant professor of statistical genomics, to understand which genes impact various traits.
Carter said mapping the genome is a good starting place, but much remains to be discovered.
“It’s a big genome, it’s complex,” he said. “A lot of what they call repetitive DNA that really doesn’t code for anything, we don’t think. Trying to piece that all together is still going to take some time.”
Pumphrey said the achievement represents “a tipping point.”
He compares the achievement to the dramatic increase of diagnostic tests in human medicine.
“We’ve been able to do this type of research for years, but it was extremely cost-prohibitive, time-intensive or labor-intensive,” he said. “This sort of democratizes our ability to do more research.”