Seeking to avert billions of dollars in crop damage from a variety of new and re-emerging plant pathogens, U.S. agriculture experts are combing the globe for disease-resistant crop varieties. But a new report warns that crop genebanks around the world that may hold the necessary genetic resources are suffering from under funding and neglect, jeopardizing the future of farming in the U.S. and globally.
The report, “Securing the Future of U.S. Agriculture: The Need to Conserve Collections of Crop Diversity Worldwide,” published by the University of California Genetic Resources Conservation Program, points to deteriorating conditions in the world's crop genebanks as a major threat to U.S. agriculture, which is already losing at least $20 to $33 billion each year to plant pests and disease.
In an age when all the world's agriculture is interconnected-whether by trade, the exchange of crop genetic resources amongst plant breeders or the spread of disease-the economic vitality of U.S. agriculture and, indeed, global food security are inextricably linked to the fate of crop genebanks,” said Calvin Qualset, a plant genetics expert at the University of California-Davis and co-author of the report.
U.S. Agriculture Needs New Sources of Disease Resistance. The report notes that nearly every major U.S. crop is battling a plethora of new or re-emerging pests against which it has little to no resistance. In each case, biologists are searching through U.S. and international genebank collections to find genes for disease resistance that can be bred into new crop varieties. These include:
Soybean: A fungus that causes a rust disease is now invading U.S. soybean fields. It can cause yield losses of up to 80 percent, threatening an $18 billion harvest.
Potato: Potato blight of the type that caused the Irish potato famine has re-emerged to threaten the American potato industry where it is already destroying $400 million worth of potatoes each year.
Corn: U.S. corn production, worth $30 billion annually, is facing multiple assaults from several diseases, including some that are capable of crossing borders with ease and have recently emerged here
Wheat: Fusarium head blight, or scab, has already caused $3 billion in damage to the U.S. wheat and barley industries.
Apple: The $1.8 billion U.S. apple industry is vulnerable to destructive bacteria that cause fire blight disease. The bacteria are becoming resistant to anti-biotic pesticides that once controlled them.
Citrus: All types of citrus cultivated in the U.S., where they generate $2 billion annually, are vulnerable to citrus canker and citrus blight.
New crop varieties
The report notes that crop genebanks are also invaluable to U.S. agriculture because they provide American farmers with access to new crop varieties to meet changing consumer demands. Higher incomes are spurring demands for higher quality foods; an aging population wants healthier foods; surging demand for organics has made organic food production an $11 billion industry in the United States; and a growing ethnic population is seeking out produce once rarely grown on American farms. In each case, staying abreast of the market requires access to genetic diversity.
These same genebanks are essential to improving agriculture and thus aiding economic development in poor countries, and to jumpstarting farming after natural disasters or wars. Today, genebank resources are helping to rebuild agriculture in Iraq and Afghanistan, as well as in countries devastated by the Asian tsunami of December 2004.
Another recent study illustrates just how central genebanks have become in the ongoing effort to breed improved crop varieties. The study reports that of 600,000 requests for 10 key crops distributed by the U.S. National Plant Germplasm System in the 1990s, two-thirds sought specific traits. Thirty-seven percent of these were requested in a search for pathogen resistance or tolerance; 14 percent for tolerance to environmental stresses; 17 percent for traits to improve quality; and 12 percent for traits that improve yield.
“Whether to fight crop diseases, stay abreast of changing markets, or aid international reconstruction and development, agriculture requires the broadest possible access to crop diversity,” said report co-author Henry Shands, director of the National Center for Genetic Resources Preservation at the U.S. Department of Agriculture's Agricultural Research Service in Fort Collins, Colo. “This diversity is being lost at an alarming rate-in farmers' fields, in the wild, and now in the very institutions meant to protect them.”
There is growing evidence that crop genebanks around the world face mounting stress. The Qualset-Shands report notes that only 35 of the 1,470 genebanks around the world meet international standards for managing long-term conservation, and more than 1 million of the 6 million samples held in these collections are degenerating.
For example, field collections of apple in Kazakhstan-the crop's center of origin-are imperiled by disease and environmental stress; a power failure in Cameroon destroyed a collection of root and tuber crops important to food security in Africa; a valuable collection of wheat, potato and other crops held in Russia is largely inaccessible because of lack of funds to translate and computerize data; and China's National Citrus Germplasm Repository has lost up to 60 percent of its collection.
One potential solution, according to the report, lies in the newly created Global Crop Diversity Trust, an independent, international organization that was established in 2004 to support crop diversity conservation over the long term. Initiated by the United Nations Food and Agriculture Organization (FAO) and the Consultative Group on International Agricultural Research (CGIAR), the Trust is building a $260 million endowment through donations from national governments, philanthropic foundations, and private corporations. The first priority of the Trust is to rescue collections that are at risk today. The governments of Cape Verde, Colombia, Ecuador, Egypt, Ethiopia, Jordan, Mali, Mauritius, Morocco, Peru, Samoa, Serbia and Montenegro, Sweden, Syria, Togo, and Tonga have so far signed on as supporters of the Trust. The government of Ethiopia, one of the poorest countries in the world, recently donated $50,000 to the Trust endowment. The Trust has raised about $56 million so far.
“We need to be collecting, conserving, and growing out seeds from around the world because in many cases, the only places plant breeders will be able to find particular genes or combinations of genes will be genebank collections,” said Peter Raven, director of the Missouri Botanical Garden and a National Medal of Science recipient for his work in plant diversity. “Today's farmers rely on such a narrow range of crop varieties that many valuable ones just aren't being cultivated anymore. And if they're not saved in a genebank, they may be lost forever, to the great detriment of agriculture and human food security.”