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FEATURE ARTICLE

Wild Plants to the Rescue

Efforts to domesticate new, high-yield, perennial grain crops require patience and persistence—but such plants could transform agriculture

David Van Tassel, Lee DeHaan

2013-05VanTasselF1.jpgClick to Enlarge Image“You had to spend all those years in graduate school to do this?” my mother asked in disbelief. I was walking slowly backwards and dragging a heavy board, at the end of which was another heavy piece of lumber with foot-long bolts sticking through it at three-foot intervals. As the bolts scraped the soil they made parallel lines. I was trying to make those lines as straight as possible.

The reason I was dragging this medieval-looking contraption, and the reason my coauthor Lee DeHaan had built it, was to form a giant grid to help correctly place thousands of seedlings of a wild sunflower relative, Helianthus maximiliani. The seedlings needed to be at equal distances from each other and in an arrangement that allowed us to map their location. Each seedling was genetically unique, with a known family history, and each had an empty row in my spreadsheet waiting to be filled with data: height at flowering, number of seed heads, stalk diameter, leaf length and width, number of seeds per head, weight of 100 seeds. Most of these traits are fairly objective and would be measured by pairs of student field assistants, one with a ruler or measuring pole, the other with a notebook or handheld computer. For consistency, I would need to score other, more subjective traits: foliar disease severity on a scale from 1 to 9, percent of heads at a certain stage of maturation on a certain day, severity of lodging (the tendency of stalks to lean, droop or even collapse).

Because these plants are long-lived, we would be collecting data for two seasons. We would get to know the plants intimately. But of the 1,000 in this experiment, only the top-ranked 50 would be kept and mated together, their offspring used to create the next breeding population. The remaining 950 would be ruthlessly plowed in. I was molding a hardy but agriculturally useless wild plant into an oilseed grain crop, something natural selection could never have accomplished. Like a god—but a sweaty, exhausted one.

Of course, all Sylvia Van Tassel could see was her tired son dragging a board through an empty field for hours. I don’t think she ever visited me in September, when my research plots are a vast golden bouquet of thousands of wild sunflowers. She might not have been impressed even then: I had told her for years that my work would help feed people some day. Unfortunately, the sunflowers didn’t look much like a crop. My colleague Sheila Cox and I usually have at least one plot each year that we refer to as “the jungle,” and most of the others are nearly as tall and tangled.

Mom certainly would have raised her eyebrows at the tiny seeds the plants produce, if I had dared to show her. But plenty of people have been drawn to investigate the idea of grain crops that are perennial rather than annual. The Soviets were trying to breed a perennial wheat as far back as the 1930s. J. Russell Smith’s 1953 book Tree Crops, A Permanent Agriculture influenced a generation of ecologists and agronomists, including Wes Jackson, the founder of the Land Institute, where DeHaan and I work. In a 2010 article in Science, scientists from 21 institutions on 5 continents called for serious investment in perennial grain crops, and this call has been echoed in more recent publications. More generally, scientists concerned about the combined impact of climate change, continued human population growth and resource depletion on global food security have warned against complacency with our existing crops and cropping systems, and have urged innovative agricultural research.

Our domestication efforts take place at the Land Institute, founded in 1976. We begin with wild relatives of crops—Van Tassel’s breeding program focuses on sunflowers and DeHaan’s on wheat. We have chosen for practical reasons to use relatively low-tech methodologies. Still, our mothers might be forgiven for wondering if something doesn’t quite add up. Their highly educated sons are supposedly working on long-term food security—surely the most pressing and basic challenge for science and policy—on a bold project that many respected scientists have agreed could lead to a breakthrough. Yet here they are scrabbling in the dirt at a small organization privately funded by citizens’ donations. If this work is so important, where are the powerful institutions, the high-tech equipment, the labs full of students? On her first visit to the institute, DeHaan’s mother marveled that an organization with such a lofty mission was housed in what looked like a modest family farm.

Appearances aside, small nonprofit research organizations like the Land Institute occupy a unique niche in the crop-improvement ecosystem. Although progress requires time and patience on a scale that family members, friends and fellow scientists may find surprising, our plants improve year by year, and the prospects for expanding and accelerating this work are promising.

It’s worth noting that our definition of grains is broad. Botanically speaking, many grains are actually fruits (for example, wheat or sunflower “seeds”). For our purposes, a grain is any hard, dry seed or fruit that can be harvested like a grain—including oilseed crops such as sunflower. Many kinds of plants may offer candidates for breeding perennial grains, from desert shrubs to plants capable of growing in seawater. We hope that our work toward perennial oilseeds and cereals will inform and inspire researchers and funding organizations—those who are already at work domesticating other kinds of plants and those who might wish to begin. New staple crops with enhanced functionality will help efforts to stabilize the world’s food supply and reduce the soil degradation that comes with large-scale annual grain production.




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