Weird Sunflowers, Wonderful New Traits

Wild sunflowers grow in the strangest places—just ask Tom Gulya and Gerald Seiler. They're Agricultural Research Service (ARS) scientists who collect the plants’ seeds during trips across the United States. Their collections help keep farm-grown sunflowers healthy.

For example, while traveling in Colorado in 2005, they noticed wild sunflowers growing beside a McDonald’s restaurant parking lot. On another trip, in southern California, they found a different species—a vine-like sunflower clinging to the backs of shifting sand dunes.

Gulya and Seiler collect wild sunflowers once or twice a year. They usually end up driving 2,500 to 3,000 miles per trip—much of that on country or back roads.

They prefer to travel in August and September. That’s when the plants’ seeds are fully developed and still attached, rather than having fallen to the ground.

The scientists map the location of each new spot where they collect wild sunflowers, and describe the growing conditions. That way, future collectors will know where to look. But, “you can’t assume the plant will be in the same location in 10 years,” Gulya says.

For example, whorled sunflowers, which grow up to 15 feet high, were first described in Chester County, Tennessee, in 1898. Then the species disappeared until 1994, when scientists found it in Floyd County, Georgia.

So why bother collecting wild sunflowers at all, especially if they may or may not be around for long?

Wild sunflowers are like hidden treasure chests. Instead of gold, though, they carry new traits that can improve commercially grown sunflowers. Sometimes, commercial varieties fall short in fighting off new diseases or insect pests, like the red sunflower seed weevil.

But somewhere, there’s a wild relative that gets attacked all the time and still survives. Scientists can breed that wild sunflower's defenses into commercial sunflowers so they, too, will survive.

Traits from wild sunflowers can also improve a commercial variety’s survival in poor growing conditions. So, “if we’re looking for drought tolerance, it would make sense to look for sunflower species growing in the desert,” says Gulya.

Most crops grown in North America, including wheat and oranges, were introduced from other countries. But sunflowers are U.S. natives.

Collecting wild sunflowers doesn't just help improve commercial varieties; it also helps preserve wild species whose habitats are threatened by human activity or even by natural disasters, like forest fires.

Not surprisingly, “there are enough areas here off the beaten path to find wild sunflower germplasm,” says Gulya. Germplasm includes seeds, cuttings, and buds.

ARS scientists have been collecting wild sunflowers since around 1976. Today, over 2,100 seed specimens are in storage for safekeeping and future use.

The dollar value of passing traits from wild specimens into commercial sunflowers is as much as $384 million a year. So you could almost say wild sunflowers are worth their weight in gold.

—Jan Suszkiw, Agricultural Research Service, Information Staff

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