Peanut Genome Project to Lead to Faster Development of New Varieties

Originally published in the April 30, 2014, issue

 

By Dallas Duncan

 

Now that the peanut genome has been
sequenced, breeders will be able to create
resistant cultivars at a faster pace using
traditional breeding methods. Photo by
Dallas Duncan

Recent breakthroughs in peanut breeding could significantly decrease the time it takes to develop new cultivars.

 

The International Peanut Genome Initiative, of which University of Georgia’s Scott Jackson was chair, completed sequencing the entire peanut genome this spring.

 

“The state of Georgia produces 40 percent of the US peanuts,” Jackson said. “One of the things we wanted to do was accelerate the improvement of peanuts – get better faster and finding varieties of peanuts with improved traits and characteristics and yield we can provide to the farmers.”

 

And one of the best ways to do that, he said, is to understand the genetics of the peanut itself.

 

“The genome sequence gives us a picture of all the genes in the cultivated peanut in one database,” Jackson said. “Now the hope is that we can use this information to make more informed decisions on what genes to move into improved varieties and how to deploy those, how to stack genes and get improved yield and improved disease resistance.”

 

The peanut joins a list of other organisms with sequenced genomes, including the chicken, peach, rice, soybean and even human, which is only slightly larger than the peanut genome. The peanut genome initiative was funded through commodity groups, shellers, growers and packers, he said.

 

Based on genetic studies, breeders can look at which pieces of DNA correlate with a trait. This leads to using the DNA and not a trait to base selection on, said Peggy Ozias-Akins, horticulture professor at the University of Georgia-Tifton campus.

 

“It’s more long-term to actually select based on the trait,” she said. “If you’ve already shown that DNA is associated with resistance to that disease, then you can still make progress in that year selecting lines out of the population that would carry resistance.”

 

Without a sequenced genome, it could take anywhere from 10 to 20 years to determine what genes control certain traits. Jackson hopes that the sequenced peanut genome will cut that time to less than a decade.

 

“Before, a breeder had to grow the plant for a whole season to see if it contained a particular trait,” said Don Koehler, executive director of Georgia Peanut Commission. “Now after the initial cross takes place … he can look for specific markers to know if a gene is present or not.”

 

The actual sequencing process is like a complicated jigsaw puzzle, Jackson said.

 

“We take the DNA from a plant and chop it up into very small fragments and we sequence those fragments using machines … then we use computer algorithms to try to put it back together in the correct order,” he said.

 

In other words, Jackson said, it’s as if that jigsaw puzzle was a picture of blue sky.

 

The next step uses more computer calculations to determine where the genes are in that puzzle, and tie the genes to a function, such as disease or drought resistance.

 

“The actual figuring out of what the genes do will take a number of years,” Jackson said. “We’re already making progress.”

 

Some of the major diseases affecting Georgia peanuts are tomato spotted wilt virus, white mold and leaf spot.

 

“By finding resistant gene strains in the peanut, the technology will allow for peanut cultivars that will help enhance production on the farm and save the farmer time and money when treating the disease,” Koehler said.