An open house will be held Friday, April 21, to dedicate a new $6 million facility at the University of California, Davis, devoted to importation, quarantine and distribution of disease-free grapevines and other agricultural and horticultural plants. Displays and tours will be offered from 3:30 to 5 p.m. at the one-story National Grapevine Importation and Clean Stock Facility, located on Hopkins Road, just west of the University Airport and south of Hutchison Drive. In addition, UC Davis Chancellor Larry Vanderhoef, Rep. Vic Fazio and industry representatives will speak. Invitations to the open house may be requested from the Foundation Plant Materials Service at (916) 752-3590. The 15,620-square-foot complex, one of only three such facilities in the nation, includes laboratories, screened plant houses and greenhouses needed to detect diseased plants and to produce healthy grapevines and other plants. It was financed by a combination of federal, university and industry funds. "California's vineyards are vulnerable to countless diseases and destructive pests," says Deborah Golino, a plant pathologist and director of the new facility. "The work done here will not only improve vineyards throughout the country, but will also give growers worldwide access to new grape varieties and clones with which to replant their vineyards." Private nurseries and wineries import grapevines from a variety of countries, including France, Italy, South Africa, Switzerland and Australia. These plants are first delivered to the grapevine importation facility at UC Davis, where they are tested for at least two years for the presence of diseases. The lengthy stay is necessary in order to complete not only laboratory tests, but also field trials, according to Susan Nelson-Kluk, the grapevine program manager. Grape materials are tested by removing buds and grafting them into grape varieties that are extremely sensitive to disease. Disease from the bud will show up after the test vines are planted and grown in the field for up to 18 months. If disease is detected, the importing nursery can choose to have the plant materials destroyed or pay to have them treated to eliminate the diseases. Staff members at the grape importation facility treat diseased materials by regenerating a new plant from a tiny piece removed from the growing tip of the original material. "The theory is that the virus has not invaded the cells at the very tip of the vine," said Nelson-Kluk. Plants produced from the tip by this "microshoot-tip culture" process are tested again to make sure that the disease has been removed. In addition to screening grapevines for diseases, the facility also produces, maintains and distributes tested, disease-free strawberries, roses, and deciduous fruit and nut trees. These "clean stock" are the foundation plants from which nurseries can propagate California-certified plants that they sell to growers and retail nurseries.