The Ultimate Crop Insurance

In late summer 2002, looters threatened war-engulfed Afghanistan’s agricultural heritage. Unknown pillagers dumped stocks of carefully labeled seeds as they ransacked buildings in Ghazni and Jalalabad, where the material had been hidden for safekeeping. All the looters wanted, apparently, were the plastic and glass jars in which the seeds were stored. The scattered seeds weren’t the starter for next year’s crops but the genetic backup for the agrarian nation’s agriculture. The catalogued seeds of various strains of wheat, barley, chickpeas, lentils, almonds, pomegranates, and melons would have been deployed to create new seed supplies if drought, insects, or some other disaster had wiped out the region’s production of crop seeds. They also represented the raw material for creating future lines of crops.

Botanists had recorded where each seed type had come from and information about the climate and geography of its place of origin. However, seeds for cold-tolerant wheat didn’t look any different from those for a cold-sensitive but disease-tolerant plant. Removed from their labeled jars, these and all the other seeds lost their archival value.

“It’s like having a library of books with no titles on them,” notes Geoffrey Hawtin, the former director general of the International Plant Genetic Resources Institute in Rome.

Seed repositories, such as those in Afghanistan, sometimes called gene banks, are often casualties of war, says Ruth Raymond of that institute. “Cambodia, Rwanda, Somalia, Iraq—we know of at least 50 or 60 examples of where it’s happened,” she says. Bank holdings often offer looters the makings for dinner or free seed for a small crop. In most cases, these events haven’t turned into long-term disasters because gene banks in other countries house backup stores. That’s true for Afghanistan and the other war-struck countries. When hostilities subside, a country can begin rebuilding its gene bank with seeds from half a world away.

Offering such relief to an embattled country is just one of the missions of gene banks, which together form an informal international system. The banks also preserve the genes that have helped plant species thrive in harsh climates, survive diseases, or provide particular flavors or other appealing traits.

Crop diversity constitutes agriculture’s “global wealth—the set of genes that have been developed by farmers over 10,000 years,” explains Clive Stannard of the United Nations Food and Agriculture Organization in Rome.

Unfortunately, the successes of large agribusiness companies are adding to the need for a strong seed-repository system and worldwide crop diversity.

A small number of popular, high-yielding crop varieties bred by these companies have increasingly edged out landraces, the varieties adapted to localized conditions during millennia of farming. If not archived in a secure, internationally sanctioned gene-banking system, these ancient varieties could disappear, taking with them as-yet-undiscovered genes for important traits.

A decade ago, a United Nations treaty on species conservation had the unintended effect of erecting roadblocks to gene banking and breeding. But on June 29, a new International Treaty on Plant Genetic Resources for Food and Agriculture went into effect. Supporters hope it will break down those obstacles and bolster the gene-banking system, and help preserve the genetic heritage of crops.

To the rescue

In December 1993, the Convention on Biological Diversity entered into force, signed and ratified by most nations. The convention dramatically changed how governments, corporations, farmers, and even tribal chiefs in countries such as Brazil viewed the agricultural and wild plants growing around them.

Gone were the days when bioprospectors from industrial nations could drop into a jungle, pluck any intriguing plant and ship it home for analysis, and then extract a substance for use as a high-value, patentable drug. With the new treaty, companies would have to work with locals and share profits (SN: 5/29/04, p. 344: Available to subscribers at http://sciencenews.org/articles/20040529/bob8.asp).

The treaty established the principle that a nation holds sovereign rights to the genetic resources of any plant within its borders (SN: 6/20/92, p. 407). But agricultural policymakers quickly recognized that this seemingly straightforward attempt to protect countries from exploitation was at odds with both the nature of agriculture and the conservation of cultivated resources.

It’s not easy to determine who deserves sovereignty over plant genes. Throughout history, people have been trading edible plants, so most farmed crops have murky national origins.

In the wake of the 1993 biodiversity treaty, many nations expressed a new reluctance to continue sharing banked seeds freely, lest they forfeit their legal rights to a plant’s genetic resources.

Suketoshi Taba encountered this change in attitude when he tried to head off an apparent crisis affecting seed corn in gene banks throughout Latin America. Taba heads maize genetic resources at the International Maize and Wheat Improvement Center, which is known worldwide by its acronym in Spanish, CIMMYT. It’s located near Mexico City.

Budgets for maintaining gene banks had been compromised by a regional economic downturn in the early 1990s. Many seeds were not being sufficiently dried before storage, and refrigeration units in the storage facilities often lost power or broke down. The proportion of banked maize seeds able to germinate at any given time should exceed 85 percent, he says, but had fallen well below 50 percent.

To rescue seeds from banks in Cuba and 12 other Latin American nations, Taba offered to have the imperiled seed stores replanted locally and the next-generation seeds shared between the various nations’ banks and CIMMYT. The countries initially balked, arguing that these seed stocks, though imperiled, were their property. In the end, botanists prevailed over politicians, and Taba saved 10,000 sets of seeds at a cost of only slightly more than $1 million.

The 1993 treaty, which essentially nationalized genetic resources, created other potential obstacles to improving crop seeds. It encouraged countries to require a seed company or laboratory to work out an international contract every time it imported seed. The cost of legal review, DNA analysis of each batch and supervision by treaty-enforcement officials would be staggering. “You would just close down plant breeding as a science,” Raymond says.

On the menu

By the mid-1990s, a groundswell developed among nations for a remedy to the Convention on Biological Diversity. In late 2001, after 7 years of debate, negotiators from about 120 countries finally settled on the outline of the new crop biodiversity treaty.

The new treaty promotes the collection and banking of seeds, the sharing of seeds among countries that pledge to honor the treaty, and an international survey of genetic resources currently existing in gene banks and farmers’ fields around the globe (SN: 7/17/04, p. 45: Available to subscribers at Treaty enacted to preserve crop biodiversity). The treaty also promises to improve crops for farmers, especially those living in harsh environments.

During their wrangling, negotiators imposed limits on what plants would be covered by the new treaty. Just 35 food crops and 29 plants for livestock forage made the list. Although reasons for a type of plant not making the new treaty’s list vary, politics often proved a major factor, says Patrick Mulvany of ITDG, an international sustainable-development foundation in Rugby, England.

If a company breeds a new plant variety from foreign seeds of one of the 64 plants included, the treaty permits that company to commercialize the crop. However, a share of any profit must be contributed to a treaty fund for programs in developing countries to promote sustainable farming or conservation of genetic diversity in crops.

When the treaty qualified to go into force earlier this year, 40 nations had ratified it. Since then, 15 more nations have joined the group, and more are poised to do so.

The United States remains a major holdout among industrial nations. It was among the negotiators of the latest treaty, but the Senate hasn’t taken up the treaty. A leading reservation, U.S. officials say, is concern over preserving commercial rights to a share of the profit for seeds passed between countries. Still to be worked out are the size of those royalties, whether they should be paid when seed is first imported or when a crop is marketed, how long a seed developer must pay royalties, and whether royalties should vary by crop.

Still, says Peter Bretting of the U.S. Agricultural Research Service in Beltsville, Md., “the U.S. government is certainly conceptually supportive of the treaty.”

The Convention on Biodiversity continues to govern the commercial exploitation of plants not listed under the new treaty. These include some important food crops, such as soybeans, peanuts, onions, and grapes. In these cases, countries negotiate individual commercial agreements without any contribution to an international program.

Bankers’ blues

The new treaty’s biggest current initiative is creating the Global Crop Diversity Trust, which will be an autonomous agency that coordinates the 1,500-or-so gene banks scattered throughout more than 100 nations. Among the largest are the 11 international facilities affiliated with the Consultative Group on International Agricultural Research (CGIAR). Together, they store some 600,000 genetically distinct seed samples.

All CGIAR members will “sign agreements with the treaty, by which they will put their entire collections under its policy guidance,” Stannard says, The United States has its own system of more than 20 gene banks. They hold some 450,000 samples of roughly 10,000 plant species. Seeds maintained in these facilities at temperatures above freezing might require replanting every 5 to 10 years to stay viable.

The nation’s biggest gene bank, located in Fort Collins, Colo., holds duplicates of seeds kept in all the other U.S. facilities and stores most of them at –18°C to –55°C. At these temperatures, metabolic processes slow and the aging of seeds is delayed, so seeds stay viable for 50 to 100 years, explains Bretting.

Unfortunately, Raymond notes, most of the world’s seed repositories aren’t as well maintained or financed as the U.S. facilities are. Seed maintenance is “not sexy,” she laments, so most governments neglect it. “How excited can you get about funding refrigeration?” she asks.

Yet, says Raymond, gene banks are an “essential insurance program to guarantee that genes will remain safe and accessible for future crop improvement.” This is becoming increasingly important, she notes, as biological diversity wanes throughout the world.

Diminishing diversity

In the 1950s, Chinese farmers grew about 10,000 varieties of wheat. Two decades later, Raymond notes, the number had fallen to 1,000. India experienced a similar loss of rice diversity over the past 3 decades, she says. And throughout the Andes, the cradle of tomatoes, wild-tomato species have become so imperiled that “before too long, the only real examples of tomato diversity will be in a gene bank,” she says.

Raymond cites U.N. estimates that one in 12 flowering plants—including crop types such as wild potatoes—will go extinct within 2 decades.

Commercial plant breeding has also been winnowing plant diversity, observes Marilyn Warburton, a molecular geneticist at CIMMYT.

Commercial growers prefer uniformity in crops for the sake of mechanized harvesting, so breeders have focused on developing high-yielding crops that will grow the same size across a field; respond consistently to weather, climate, and nourishment; resist blights; and mature within a tight window of time during harvest season.

Warburton has confirmed great genetic variability in landraces of wheat planted in developing countries before the agricultural movement that came to be known as the green revolution. Her DNA analyses show that in their efforts to achieve the high yields, CIMMYT and other green revolution breeders “reduced diversity in traits sampled throughout the genome.”

Warburton notes that wheat yields have lately leveled off in many developed countries, despite intense breeding efforts to raise them. This has fostered speculation, she says, that commercial breeders might have “run out of genetic variation.”

Her CIMMYT colleagues, however, have developed what they call synthetic bread wheats, which demonstrate that genetic crop diversity can be restored or even amplified. Over a 15-year period, Abdul Mujeeb-Kazi and his team crossed banked seeds that represented the original wild parents of durum wheat and then crossed their progeny with another wild wheat. This effectively duplicated the natural events that originally gave rise to bread wheat some 10,000 years ago.

CIMMYT scientists have since repeated the process to produce additional synthetic bread-wheat lines.

Warburton’s analyses of these lines’ DNA now show that genetically, “they are about as diverse as the original landraces of wheat.” However, she notes, the new wheats give up to 50 percent higher yields than the original green revolution lines and yields similar to the best commercial yields today. An added benefit: The new wheats are extremely resistant to environmental stresses, such as pests, drought, and salty soils.

Plant triage

Healthy, well-stocked gene banks make such a success possible. Unfortunately, Raymond observes, those in the United States and the CGIAR system aren’t typical. Most banks are ill funded and have outmoded equipment. A few amount to little more than a stash of seeds in a bureaucrat’s refrigerator.

The Global Crop Diversity Trust is inventorying gene banks to identify those in need of rescue. Nations, foundations, and individuals are being asked to donate funds to upgrade facilities that are in dire straits, especially banks with important collections. Once these gene banks gain solid footing, they may qualify for annual funds from a new endowment being set up under the trust.

Raymond has been charged with spearheading a campaign to raise an additional $260 million to establish that endowment, which should eventually permit annual disbursements to gene banks totaling some $12 million for boring budget items such as payments for electricity and new refrigerators.

“What we’re requesting is chicken feed,” she says. However, she adds, even this small endowment could yield big dividends in developing countries. “And it’s for such a great cause,” she argues ardently. “I mean, we’re talking about the [agricultural] security of the world.”

---