Researchers unite to unearth clues on potato disease
In 2007, a disease found elsewhere in the world began cropping up in potato plants in the United States. Named after the dark stripes it creates on cooked potatoes, zebra chip pathogen spreads by potato psyllid insects. From tablestock to chipping potatoes, it affects all market classes of potato plants causing them to die four to six weeks after infection.
To fight the invasive disease and develop disease management strategies for the $3.5 billion U. S. potato industry, researchers from across the country came together to offer their expertise.
That team, named the Zebra Chip Leadership Team, includes NDSU University Distinguished Professor of plant pathology, Neil Gudmestad. He and four other members were recently presented the Partnership Award by Texas A&M AgriLife for their outstanding collaboration. The honor recognizes individuals or teams that develop and participate in partnership efforts with communities, industry, agency, university and/or associations that advance the mission of Texas A&M AgriLife to serve Texans and the world.
“I am just one member of this research team, but I am proud of what we have been able to accomplish in such a short period of time,” Gudmestad said, noting they have published more than 100 peer-reviewed manuscripts since they formed in 2009 after receiving a five-year $10.2 million grant from the United States Department of Agriculture-National Institute of Food and Agriculture-Specialty Crop Research Initiative.
Gudmestad serves as a co-director along with John Trumble from University of California-Riverside and Charlie Rush from Texas A&M. Each leads a different aspect of the research.
Gudmestad oversees a team of pathologists studying the bacterium’s variability, detection and biology. Specifically, his group is working to sequence a new biotype dominant in the United States. Through working with another research group in New Zealand, where the disease also is economically damaging, they hope to learn what competitive advantages the new strain has gained and how it differs from the strain it replaced. The subgroup also is working to develop molecular technology for pathogen detection to improve disease control and provide more powerful tools to study pathogen epidemiology.
Rush is responsible for the epidemiology and risk assessment team, while Trumble, an entomologist, leads a team working with the insect vector that transmits the zebra chip bacterium.
Other team leaders include James Supak and J. Creighton Miller. Supak, a retired Texas A&M administrator, serves as a liaison between the research team and the “Texas Initiative,” a consortium of the Texas Department of Agriculture, potato processors and potato growers who contribute approximately $1 million annually to zebra chip research. Miller, a potato breeder in the horticultural sciences department at Texas A&M, leads research searching for genetic resistance to zebra chip.
Gudmestad said zebra chip is a primitive unculturable bacterium with four biotypes, two of which affect potato production in the United States. Zebra chip doesn’t harm the consumer. It is aesthetically unpleasing and when cooked it creates an unpleasant bitter taste due to over-caramelized sugars in the affected areas.
His experience with the disease started almost 20 years ago, when Gudmestad and Gary Secor, NDSU plant pathology professor, first observed the pathogen in 1994 in the León region of Mexico. Later reported in Texas, it has since spread to New Mexico, Kansas, Nebraska, Colorado, California, Oregon, Washington and Idaho.
“It went from a minor disease to a major disease of potato in the United States and New Zealand within a decade. It’s what invasive pathogens do when they get into a country and there is no natural resistance in a plant species such as a potato,” Gudmestad said, noting the economic losses due to zebra chip in New Zealand are calculated to be more than $100 million annually. He said the most recent agriculture economist figures indicate the cost of controlling zebra chip in the Unites State exceeded $15 million in 2012.
He and Secor first began studying zebra chip at NDSU in 2005. Although the disease isn’t in North Dakota, it’s of interest because several growers affected by the disease are headquartered in the state.
“It is difficult to work on a disease that is 1,500 to 2,000 miles away,” Gudmestad said. “I immediately started collaborations with a Texas A&M colleague I knew, Dr. Charlie Rush, a very experienced epidemiologist.”
The collaboration evolved over time. Today, more than 30 scientists representing seven universities and U.S. Department of Agriculture researchers from seven states contribute to zebra chip research to improve growers’ outcomes.
The Zebra Chip Leadership Team has received two major accolades for their work.
The Partnership Award is a Vice Chancellor’s Award in Excellence, the highest employee award given by Texas A&M AgriLife, which has teaching, research, extension education, laboratory and forestry facilities throughout Texas. It was presented Jan. 8 at Texas A&M University, College Station.
They also received the second highest honor from the Entomological Society of America – the Team IPM Award.
Gudmestad said the Texas A&M recognition is especially rewarding. “It is a great honor for the entire team,” he said. “But it is particularly rewarding to be honored by another university.”
NDSU is recognized as one of the nation's top 108 public and private universities by the Carnegie Commission on Higher Education.