U.S. Potato Genebank Works to Improve Potatoes’ Genes

The U.S. Potato Genebank is just that a bank containing 5,000 populations kept as botanical seed, encompassing about 150 species.

Our responsibility is to collect, classify, preserve, distribute and evaluate potato germplasm,” said John Bamberg, project leader for the genebank. “This is the only genebank for potatoes in the United States.”

The genebank, located in Sturgeon Bay, Wis., is part of the National Plant Germplasm System of USDA, which is funded through the Cooperative State Research, Education and Extension Service and USDA’s Agricultural Research Service. The program also has direct and indirect support from University of Wisconsin-Madison.

The U.S. Potato Genebank began in the late 1940s because potato was a quarantine crop, and most potato germplasm comes from a foreign source there are only a few potato species native to the southwestern part of the United States. Materials that were imported were potential threats to the crop, as they could contain diseases. And as people shared those materials for research and breeding, those diseases could spread.

“We needed to have a central location to organize those materials,” Bamberg said.

To gather the germplasm, teams would go to foreign countries to areas where there were known to be wild potato species growing. These areas were located through old records based on specimens or on botanists’ information.

The teams collected these materials and brought them back to the U.S. Potato Genebank for classification and research.

There isn’t as much traveling anymore to collect germplasm of wild species.

“Within the recent past, it’s been shut down because of issues of national germplasm ownership,” Bamberg said. Now, most of the germplasm is collected from other researchers and genebanks around the world.

“If there’s anybody around the world who has something we think will be of use, we request (the materials) and import them here,” Bamberg said.

Bamberg does any domestic collections in the Southwest.

Prospecting for new traits isn’t an easy job. It’s not just a manner of locating the wild species; there is a vast array of genetic diversity among different species of wild potato.

“There’s almost unlimited (characteristics) we could keep,” Bamberg said. “We have to to some extent pick and choose what we keep.”

The genebank is one more resource for breeders looking for specific information. And because there are so many traits, the job is too big for the breeders to handle alone.

“I feel like we have some role in that since we have this huge panorama of diversity that other people aren’t looking at,” Bamberg said.

The potato of commerce is a narrow slice of the spectrum of potato diversity found in wile and primitive cultivated species.

“How can you apply the whole breadth of potato diversity?” Bamberg asked. This is one role of the genebank.

Improving Potatoes

The genebank team is looking to improve cultivated potato varieties in a number of ways, including improving nutritional value, increasing production ability and making current varieties more diverse. Other improvements the team is looking to make are in disease, pest and stress resistances.

“I look at it as a genetic tool box,” Bamberg said. “You want to have a diversity of tools so whatever breaks down, you can fix it.”

Bamberg stressed that they are not doing any GMO work at the genebank. Instead, he said, they broaden the genetics by breeding with potato relatives.

The ultimate goal is to make the potato more useful be it to consumers or to growers.

One of the projects the team at the genebank is working on now involves a small protein in potatoes that appears to be a strong anticancer agent an agent that is almost unique to potatoes.

“There’s evidence it’s pretty effective on some pretty ugly cancers,” Bamberg said. “We are also working on screening for antioxidants in white-fleshed potato. Other people are working on antioxidants in colored potatoes, but it would be great to make the point that (potatoes) don’t have to be colored to have antioxidants.

“The kinds we are already eating could make a great improvement in the American diet. It is very important to consider the power of potatoes’ per capita consumption. Thus, a small improvement in potato could have much greater overall impact than that of other vegetables that are rarely eaten.”

There are a number of other traits the genebank is evaluating and plans to evaluate in the future: late blight, high tuber calcium and potassium, and cold tolerance, for example.

The genebank isn’t the be-all, end-all of potato germplasm work, of course. There are many researchers across the country who work with Bamberg’s team to continue work started at the genebank.

“Our own work with regard to different traits has to be a jack-of-all-trades thing,” he said. “If we find something exciting or have a reason to think we can contribute to an already known disease resistance but only in an introductory way, we’ll then turn it over to a specialist to continue with that.”

And some characteristics that would seem to be helpful in improving potato genetics may not be used directly in breeding at all.

“If you found a very high expression of a certain trait in a wild species, (it) may never be used as a parent for a new cultivar but it may be used to refine the technique for evaluation,” Bamberg said. “We could make a lot of advances if we had improvements in breeding efficiency and genetic tools.”

Though the genebank is one step removed from the grower community, the work is important to growers. The material from the genebank goes to breeders who release new varieties for the industry.

“If we’re going to continue to stay competitive, we’re going to need better varieties,” Bamberg said. “Potato is a real standout in that regard. Other crops don’t have nearly as many exotic relatives in their pedigrees as potatoes. Eventually, that means better resistances, better versatility and better product.”

And Bamberg said the genebank is an important component in the potato industry’s continued success.

“It’s the only practical source of new blood for potato breeding in the country,” Bamberg said. “And is that important? Yes because potatoes need it.”

Learn more about the U.S. Potato Genebank at www.ars-grin.gov/nr6/.”