Southwest Environment

Stories written by University of Arizona students

Department of Soil, Water and Environmental Science
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Saving diversity among plants through produce

organic and heirloom producePhoto by Eduardo Bastidas
"Heirloom" tomatoes have greater genetic diversity than the typical commercial variety, so they don't look identical on the shelf

By Eduardo Bastidas, May 26, 2010

The symmetrical floor plan of most grocery stores is broken here at Tucson’s Food Conspiracy Co-op, where aisles don’t fall into parallel lines. Clerks occupy their checkout stations in casual clothes, abandoning matching company uniforms. Some of the products that they bag for their customers are also unique.

Co-op Outreach Coordinator Torey Ligon said there is always at least one “heirloom” product available at the store, which is located near the University of Arizona on Fourth Avenue. Heirloom
produce refers to plants that people have cultivated for many generations as a local food source.

The Food Conspiracy Co-op, Seeds of Change, and Native Seeds/SEARCH are all examples of a fragmented but determined effort taking shape in the Southwest to preserve rare plant lines – including heirloom plants – by reintroducing them to customers.

“Many of our local farmers work with heirloom seeds,” said Ligon, adding that the Co-op regularly has heirloom tomatoes for sale. Sometimes, people can even buy their own plants to grow. “In March, we sold a thousand heirloom tomato plants.”

Demand for these heirloom plants can help save their genetic lines for the future, so putting them on the market can help this effort. Heirloom plants are the cornerstone of the effort to preserve rare plant lines, as they are often distant relatives of the crops that are mass produced today.

Native Seeds/SEARCH is another company that bridges the gap between producer and consumer in the market for heirloom plants. Located on Campbell near Fort Lowell, Native Seeds/SEARCH operates to produce and store seeds of target plants in order to distribute them to farmers and gardeners.
“What we do is conserve heirloom crops. We protect them,” said Suzanne Nelson, director of preservation at Native Seeds/SEARCH in Tucson. SEARCH stands for Southwestern Endangered Aridland Resource Clearing House.

“We specialize in heirloom aridland-adapted domestic crops,” Nelson said. Seeds from Hopi watermelon, lemon basil, sunflowers and tobacco line their shelves. “They’re unique. You can’t find these in other places.”

The effort of cultivating and distributing the seeds of heirloom and native plants helps to ensure that future generations will be able to enjoy them.

Food Conspiracy heirloom tomatoesPhoto by Eduardo Bastidas
Tucson resident Claudia Dominguez looks over the Food Conspiracy Co-op produce, which includes heirloom tomatoes.

“We don’t want to limit ourselves in the future,” Nelson said. Keeping these lines alive is essential to maintaining genetic variation among plants, which can help them survive in the long run.

In contrast, dependence on a small number of food crops can be dangerous, especially when the plants begin to lose their genetic diversity through selective breeding. The Irish potato famine in the mid-1800s, linked to the death of more than a million people, resulted when a single mold killed off most potato crops. Selective breeding had made them genetically uniform.

Such a lack of genetic diversity can lead to genetic erosion. In the worst-case scenario, the species loses an entire gene.

Simply put, genetic erosion is “the loss of genes which code for characteristics in plants,” said Marc Cool, general manager of Seeds of Change, a company located in New Mexico. “The issue is that once such a gene is gone, the characteristics they code for are lost, and we don’t know under which conditions these characteristics could be of value in the future.”

Like Native Seeds/SEARCH, Seeds of Change seeks to preserve heirloom and native plants by cultivating them and storing their seeds for sale.

“We have a seed bank, one of the largest organic seed banks in the world, from which we produce seed varieties to sell to gardeners and growers around North America,” Cool said.

Genetically modified plants, or GM plants, tend to become genetically uniform. Although they help the agricultural industry by increasing crop yields, GM plants are mass produced. This can lead to a loss of diversity in their gene pool. 

Because of the problems related to GM food products, the Co-op avoids selling them. “We work to limit or eliminate GM products in our store,” Ligon said. “We are a natural foods market.”

Although the Co-op, Seeds of Change, and Native Seeds/SEARCH are different companies that operate independently, they are all working to save genetic plant lines that might otherwise be forgotten.

“That message resonates with our customers,” Ligon said.

Eduardo Bastidas is a senior Molecular and Cellular Biology major at the University of Arizona's College of Science.

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