The Plant Hunters

Plant collecting has changed in many ways since USDA plant explorer Frank N. Meyer (left) walked a thousand miles from a railhead in China, collecting samples of any plant that looked interesting. On February 26, 1908, he returned tired, but satisfied, from a successful expedition in the high mountains of Shansi province in northern China. Today, trips are elaborately planned to concentrate on filling specific gaps in the plant collections of individual crops.

So where did the last peach you ate come from? Wait--don’t answer, “The grocery store!” or the name of the state where peaches are grown for sale. Instead, think about where peaches originate from--where these fruit first came from when they grew wild.

Here’s a clue: It’s not North America.

Like many people here, many of our country’s major crops are immigrants, meaning they came here from somewhere else. These immigrant crops arrived with people who brought along their traditional crops. Or perhaps the crops arrived as germplasm--seeds, cuttings, or whole plants-- collected by plant explorers.

The ancestors of today’s fuzzy, juicy peaches were collected and brought back from China in the 1920s by USDA plant explorers. Many of them were a little bit like Indiana Jones, the movie adventurer. But instead of treasures, these explorers searched for new sources of plant germplasm.

New crop varieties bred from this material stand a better chance against repeat attacks from diseases and hungry insects. Collecting new plant germplasm also helps crops get used to new or changing growing conditions. It helps keep them productive, nutritious or simply better-tasting. The secret to their success often comes from genetic material stored in the germplasm.

Yesterday and Today

In 1990, USDA marked the 100th anniversary of its official plant exploration program. The program began in 1898 with the creation of the Sections of Plant and Seed Introduction group. (See related story.)

It’s not always easy to trace the impact of those early explorations to the foods we eat today. Many of the crops our nation’s farmers grow now are generations away from what was originally collected. Here are just a few success stories: corn, soybeans, potatoes, berries, cereal grains, grapes, apples, carrots, onions, tomatoes, lemons and even grass for your lawn! (See related story.)

The parents of today’s crop varieties were just a few of the thousands of new plants and crops collected by the explorer Frank Meyer, who traveled throughout Asia and Russia.

Soybeans were one of his most important contributions. Before Meyer went to China in 1905, only eight soybean varieties were grown by U.S. farmers. By 1908, Meyer had added 42 new varieties. Thousands more have since been developed from them.

Today, USDA plant exploring and collecting is directed by the National Germplasm Resources Laboratory in Beltsville, Md. The laboratory is run by the Agricultural Research Service, part of USDA. The lab’s goal is to make sure our farmers have the right crops to grow enough food.

Figuring Out Where to Look

When you’re trying to find different types of a plant, the most important place to look is where that plant originally came from--where people have been growing it for the longest time.

“The traditional varieties that farmers have been growing for hundreds of years may not produce as much as the varieties we have today,” says Allan Stoner, leader of the ARS laboratory. “But they can have genetic traits that are exactly what we need to overcome a pest or disease problem."

Take the wheat that USDA plant explorer Jack R. Harlan and his Turkish colleague Osman Tosun found 51 years ago in a field in Fakiyan Semdinli, Turkey.

That wheat looked terrible. It fell over easily and didn’t survive the winter very well. It also fell victim to a disease called leaf rust.

By itself, “it was a hopelessly useless wheat, but was dutifully conserved," Harlan once wrote of the wheat, called simply Plant Introduction (PI) #178383.

But 15 years later, when wheat breeders needed a source of resistance to another disease, stripe rust, they called on good ol’ PI 178383. In addition, the sturdy wheat also fought off two other costly diseases--flag smut and snow mold.

Today, PI 178383 appears in the family tree of almost all wheat grown in the United States’ Pacific Northwest.

“It’s impossible to judge now just what germplasm may be essential to our future,” Stoner says. “All we can do is collect what seems to represent the diversity of a crop and its relatives, and preserve it until that day in the future when a plant turns out to be the single most important source of some critical trait."

An International Affair

If you think about it, plant exploring is an international activity by nature. USDA plant explorers have always asked permission from a host country for collecting.

Today, special agreements are often made between nations to ensure that everyone benefits from the plants that are collected, explains Karen A. Williams, a botanist who coordinates ARS’ plant exploration program.

One agreement, for example, recently teamed ARS plant explorers with Paraguayan scientists. Together, they set out on a journey to find rare wild relatives of traditional pepper varieties. ARS scientists returned with new pepper germplasm. The Paraguayans, meanwhile, gained experience in breeding, collecting, and conserving their nation’s plant germplasm.

The history of plant exploration is a rich and diverse one. Indeed, diversity is the driving force behind it. What you’ve read only scratches the surface. To learn more, check out the cover story in Agricultural Research magazine’s September 1998 issue.

—By Kim Kaplan, Agricultural Research Service, Information Staff