Laura Marek and Gerald Seiler hunt with paper sacks. Each year, they pore over old records, locate their quarry, and then cover thousands of miles across the United States to safeguard agriculture. Walking gravel roads, cutting through fields, or boating to islands, the gumshoe pair cold-nose the trail of sunflower crop wild relatives. When the prize is found on a back road or forgotten clearing, they break off sunflower heads and preserve the seeds in agriculture’s version of bag-and-tag.
Wild crop relatives fight a cage-match every day against disease, drought, and pests. They endure by developing resistance and tolerance, and their genes hold invaluable lessons for cultivated crops. Pared down, a scrawny sunflower clawing for ground beside a highway is hiding a mother lode of survival keys necessary for the future of agriculture.
Marek and Seiler have collected 2,200 unique populations and 53 genetically different wild sunflower species. They reference herbaria records, and spend loads of time checking with botanists and land managers to get new location information or gain permission to access private land. “We don’t just collect; we use the material. Our aim is to improve crop species with crop wild relatives,” says Seiler, a botanist with the USDA Sunflower and Plant Biology Research Unit in Fargo, N.D. “Sunflower is a highly managed crop and has to overcome lots of pathogens and pests. How? We go back to the wild relatives and move their genes into cultivated sunflower.”
As with many crops, sunflower relies on a narrow genetic base, which is a precarious position when disease or environmental problems strike. Seiler performs long-term, high risk research which can’t be done by major ag companies because of lengthy turnaround of products. It can take 10 years to develop a hybrid sunflower, according to Seiler. When plant researchers request a particular trait, Seiler cross-references his collection with the climate and environment of his fieldwork for a promising match. “Every day is interesting as we test material,” he says. “All we need to find is one plant with resistance and then we can transfer the gene to the cultivated side.”
Marek, curator of oil seed crops at the USDA North Central Regional Plant Introduction Station in Ames, Iowa, ships collected seed back to her lab. Her crew hangs sunflower heads in mesh drying bags and waits for insects to hatch and die. After cleaning and viability tests, seeds are stored at the Ames gene bank, and later distributed to plant breeders and scientists, with additional seed or sent for storage and safekeeping at the USDA National Seed Storage Lab in Fort Collins, Co., and the Global Seed Vault in Svalbard, Norway. “We’ve found rust tolerance to downy mildew and some resistance to Sclerotinia white mold. The big companies put these useful traits in their production lines,” says Marek.
Sunflower is one of the few native crops with economic value in North America. The 2014 U.S. crop was worth $480 million, according to John Sandbakken, executive director, National Sunflower Association. Sunflower needs an arid climate and minimal humidity. Production roughly ranges in the central U.S., from North Dakota to Texas, with 1.86 million planted sunflower acres in 2015. “Farmers are looking back at sunflower as corn and soybean prices aren’t promising. There is demand for more sunflower production, both domestically and in export markets, particularly for oil,” says Sandbakken. “Our overall goal is to increase acreage 10% to 15% each year.”
“Wild crop relatives are invaluable and people are beginning to realize their significance. In the past five years, interest has continued to increase. A lot of companies have used this material in breeding programs,” Marek notes.
As a rare native plant in the U.S., sunflower offers a physically accessible view into resistance and drought-tolerance not afforded by other crops. Marek and Seiler are grabbing while the getting is good, filling in gaps for each sunflower species. “Genetic diversity is the future of agriculture. All we know is what we can find,” says Seiler. “Sometimes people think we’re collecting weeds when they see us in the field. Weeds to them maybe; but a rare value to agriculture.”