Saving the seed spectrum.

• Author: Werner, Louis
• Position: Seed banks for heirloom plants of the New World

A small Colorado town is an unlikely site for the world's largest seed bank, a kind of Borgesian library containing nearly every food plant eaten by man, but Fort Collins is nevertheless the best place to set off in search of the Western Hemisphere's oldest fruits and vegetables. Scientists at the National Seed Storage Lab, operated by the U.S. Department of Agriculture, are experts on the family trees of tomatoes, squash, and corn - to name just a few of what have now become global staples - and are helping to broaden our understanding of pre-Columbian tastes.

The collection holds almost a half-million specimens of germ plasm - seeds deep frozen or cryo-preserved in liquid nitrogen, live cuttings sealed in test tubes, and whole plants growing in the field. Not all are native to this hemisphere, but where might one find so many - papaws, pecans, persimmons, potatoes, and pumpkins (to consider just the middle of the alphabet) - that are?

But more important than the number of different food plants in the bank is the number of the different varieties of each. Profit-driven commercial breeding and hybridizing - aimed at pleasing consumers and industrial food processors - have also reduced the taste spectrum and genetic fingerprint of what we eat. If store-bought tomatoes seem to taste and look more and more the same, one can be sure also that they ripen at the same time, require the same pesticides and fertilizers, and resist the same known diseases and weather fluctuations.

But with this loss of diversity comes vulnerability to the unpredictable. Witness the Irish potato famine of the 1850s, when a new fungus swept every field in the country, and the more recent corn leaf blight of 1970, when disease reduced the U.S. crop - most of it a single hybrid - by 700 million bushels. The next year's harvest was saved only by crossing the modern hybrid with a seed-banked variety not commercially grown yet resistant to that particular fungus.

Although backyard gardeners cannot ask the Department of Agriculture to step in with its seed-banked varieties to save, say, fungus-threatened tomatillos and chiltepines, anyone interested in growing New World food plants can buy seeds from a nonprofit organization in Tucson, Arizona, called Native Seeds/SEARCH (Southwestern Endangered...