Joseph Postman, plant pathologist and curator at the National Clonal Germplasm Repository, holds a young pear tree.

The legacy isn’t just about gathering; it’s also about preservation of the finds, a pursuit with its own inspired history. On a crisp fall day, while walking in the repository’s southern fields past Vaccinium cylindraceum, a shrubby blueberry from the Azores Islands (a Portuguese archipelago), Joe Postman, another of the repository’s curators and a plant pathologist, tells the story that has inspired him since he first heard it thirty years ago.

Adolf Hitler, with his obsession for eugenics, was hungry to claim for future plant breeding the nearly two hundred thousand samples of seeds, roots, and fruits stored in a nondescript brick building in Leningrad’s Saint Isaac’s Square. Between 1941 and 1944, while Leningrad was under siege, hundreds of thousands of people in the area died from starvation. Terrified that the hungry masses might try to break into the bank and steal the bags of wheat, barley, beans, potatoes, and peas (or that the Nazis would confiscate the samples), the staff of what is now known as the Vavilov Institute barricaded the walls and doors, locking themselves inside the dank, unheated building. Starving and numb with cold, they took shifts caretaking the seeds around the clock. When summer broke, they planted seeds in a garden outside in order to maintain viable seed potatoes. With artillery fire exploding overhead, the botanists stood constant guard over the potato plants, scaring away hungry rats and humans alike.

"It was hard to walk‚" Vadim Lekhnovich, one of the seed protectors, said years later, as recounted in a book by Gary Nabhan, a renowned conservation scientist and ethnobotanist based in Tucson, Arizona. "It was hard to get up every morning, to move your hands and feet…But it was not in the least difficult to refrain from eating up the collection…For what was involved was the cause of your life, the cause of your comrades’ lives."

Nine of Lekhnovich’s colleagues died from starvation, shrapnel, or disease during the nine-hundred-day siege. Not one of them ate the seeds under their care.

"You travel around the world where people are doing this work, saving genetic resources, and everybody takes it seriously," says Postman, speaking in his slow, patient way. He adds that seed savers don’t tend to burn out. Both he and Hummer have worked at the Corvallis lab for over twenty years. "This is not just a job; it’s a passion."

CHAD FINN, a geneticist who runs the USDA’s small-fruits breeding program, takes this zest for seeds well beyond preservation. In an effort to get more people eating healthy fruit, Finn is determined to create a cheaper strawberry—one that’s not only larger and easier to pick, but sufficiently disease-resistant to reduce the need for expensive pesticides and the cost of replanting fields. As he walks through his lab at the edge of the Oregon State University campus, past dozens of squat glasses with miniature green plants growing inside them, Finn explains the basics of plant improvement.

Taking prime seedlings grown from samples stored at the repository—say, a wild variety of strawberry that’s evolved immunity to a specific soil fungus—he doses them with the pollen of one of the large-fruited Chilean berries. The resulting plants end up in the lab’s juice-jar collection until they’re big enough to transfer outside. Once the plants are in the ground, Finn is able to see exactly what he’s created, select the best of the bunch, and start the process all over again. And again. And again. It can take years. On average, it takes as many as twenty thousand seedlings to produce one commercial cultivar, or variety. After sixteen years, Finn has released seven strawberry varieties (not to mention twenty-one other cultivars of blackberries and raspberries), each a step toward his goal. Although he’s bred a berry that’s bigger and more disease-resistant than others, he complains that it isn’t sweet enough and that it’s still not immune to certain molds. "I’m always striving for something better‚" says Finn, his hands stained the deep-blue color of bruises from sorting blackberries all day. "We’ve been striving for better varieties for one hundred years. Nobody’s ever had the perfect cultivar, but it’s like infinity—you’re never going to reach it."