- The introduction of new clones and rootstock varieties has played an important role in the development of the Oregon wine grape industry. The OSU Grapevine Mother Block has been an integral part of this overall vine improvement program providing a readily accessible source of specific pathogen tested grapevine plant material for industry and researchers. Since July 1995, the Department of Horticulture has carried out maintenance of the OSU Grapevine Mother Block at the Lewis Brown Farm, including propagation and maintenance of greenhouse grown stock plants. Additionally, the propagation and distribution of plant material from the Mother Block, previously carried out by the Foundation Seed and Plant Materials Project, is being performed as part of the viticulture research and extension program at OSU. During the 1996-1997 season, approximately 900 winegrape cuttings (600 dormant; 300 mistpropagated), 3000 rootstock cuttings (200 dormant; 2800 mist-propagated), and 10 table grape cuttings were distributed to growers in Oregon, Washington, California, New York, Virginia, and Canada. Additionally, approximately 2000 cuttings were provided to OSU and USDA researchers. Rootstocks account for approximately 77% of the total non-research cuttings distributed. Under the management of the OSU viticulture program, new clones and rootstock varieties identified to meet specific industry needs or those of researchers are being added to the Mother Block. Forty-eight new grapevine selections have been imported into Oregon from the Centre for plant Health in British Columbia, and Foundation Plant Materials Service in California since July 1995 (Table 1). Pinot blanc, Pinot gris, and Merlot are heavily represented on this list. Clones of these varieties may be included in future clonal evaluation trials in Oregon. Additionally, following an international search, Pinot blanc clones VCR 5 and VCR 7 (Italy), 122 (France), and 10-GM (Germany), and Pinot gris clones Rauscedo 6 (Italy), VCR 5 (Italy), 195-06 and 195-13 (France), and 13 Mf and 34 Bl (Romania) have been identified as clones considered to be most promising for future importation. The Mother Block will continue to provide a source of virus tested grapevine plant material for industry and researchers. During the 1997 season, in collaboration with USDA Plant Pathologist Bob Martin, virus testing using serological methods was initiated for all selections in the Mother Block. The presence of phylloxera in Oregon will eventually necessitate reestablishing the OSU Mother Block with grafted vines. A plan for carrying this out is currently in the initial stages.