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United States Department of Agriculture

Agricultural Research Service

Rock grapes rootstock.

Finding and Preserving Native American Grapes

By Hank Becker
December 1, 1998

Last summer, botanist Diane Pavek drove and hiked 12,000 miles exploring wild terrain in the United States. Her mission: find and preserve “in situ” populations of the native rock grape, Vitis rupestris Scheele. In situ means “growing in native habitat.”

Rock grape is prized as rootstock because of its excellent disease and insect resistance. It can adapt to harsh environmental conditions such as drought.

If undisturbed, this grape can continue evolving and adapting. According to Pavek, the plants may hold genes useful in developing new grape varieties. But she found the grape along fewer than half the waterways where it previously had grown.

Pavek is with the National Germplasm Resources Laboratory in Beltsville, Md. The lab is part of the Agricultural Research Service, the principal research arm of the U.S. Department of Agriculture.

Rock grape typically grows along rivers and creeks, on gravel bars and in areas with large boulders. Flooding may uproot and redeposit the plants or transport the fruits downstream, where seeds can germinate.

Pavek looked for the plants in 60 waterways in 10 states--from Pennsylvania to Texas--where the plants had previously been collected. Because of stream channeling or other changes that eliminated rock grape habitat, she found the plants on only two dozen of the 60 waterways.

At each site, she measured the plants and took leaf samples for genetic screening. In her lab, she recorded physical data on 238 plants from 19 waterways. Her analyses identified populations that differed in specific favorable traits. As a result, she has proposed seven populations as in situ conservation sites.

A story about in situ preservation of grapes and other plants appears in December’sAgriculture Research magazine. The story also is on the World Wide Web at:


Scientific contact: Diane S. Pavek, ARS National Germplasm Resources Laboratory, Beltsville Agricultural Research Center, Beltsville, Md., phone (301) 504-5692, fax (301) 504-6305,

Last Modified: 8/22/2017
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