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Sourcing grapevines in North America.

Of the numerous components required for the establishment of a new vineyard, plant material is arguably the most important. Although soils, microclimate, irrigation and trellising systems are vital, investments made in optimization of these factors is for naught if the planting material used in the development of a new vineyard is of poor or unknown quality.

The present boom in the U.S. wine industry has resulted in a significant unmet demand for grapevine plants of traditional varieties and distinct variants of these called clones. Nurseries, wineries, vine-yardists and government and industry-sponsored organizations are working to [TABULAR DATA FOR TABLE 1 OMITTED] [TABULAR DATA FOR TABLE 2 OMITTED] propagate traditional selections of grapevines as rapidly as possible. while at the same time coordinating the importation and release of desirable European clones.

Historically, the U.S. wine industry, and particularly that in California, was founded on varieties and clones selected for a combination of high yield and quality. A limited number of selections were promoted for use in the U.S. and these have been the mainstay of the industry's expansion over the last four decades. Recently, however, there has been an up-swelling of interest in the European clonal cousins of tried and tested U.S.-grown varieties, materials that have not previously been available to the U.S. industry.

Introduction and Release of New Varieties and Clones into The U.S. Market

Because of concern over introduction of exotic diseases into the U.S., the importation of grapevine materials is a closely-regulated process which involves a lengthy period of quarantine. The U.S. Department of Agriculture (USDA) provides guidelines which are implemented at state and national levels and include field and laboratory evaluation of the materials. Before imported plants can be released from quarantine, they must be evaluated for disease, and any regulated pathogens that are detected must be eliminated.

To effectively monitor the quarantine process the USDA will only grant importation permits to suitably-qualified researchers at public institutions with appropriate facilities. At this time there exist three grapevine quarantine programs within the U.S. (Table 1) although that located in Geneva, New York, provides a service for plant breeders only. An alternative, but indirect option for introduction of new grapevine material into the U.S. is to work with Agricultural Canada's quarantine and importation program based in Sidney, B.C. After passing through the Canadian quarantine program, it is relatively easy to ship clean Foundation materials of foreign origin into the U.S. Inquiries regarding movement of plant materials in the U.S. from Canada should be addressed to the USDA Animal and Plant Health Inspection Service, Riverdale, Maryland. Telephone: (301) 734-8645.

The U.S. programs comply with federal guidelines and generally take from two to four years to determine whether quarantined materials are free of important pests and pathogens. Disease status of candidate materials is determined using the following procedures:

* Field tests (2 to 3 years) where candidate quarantine material is grafted to an "indicator" plant which readily exhibits characteristic disease symptoms if the suspected disease agent is present;

* Herbaceous tests (3 to 6 months) where extracts from candidate plants are inoculated onto herbaceous plants which respond with the development of characteristic symptoms should the disease agent be present;

* Immunological (ELISA) tests (2 to 3 days) where candidate plant extracts are probed with antibodies specific to the causative agent of a specific disease.

Although all of the U.S. programs comply with federal regulations for post entry quarantine disease assessment, the panel of pathogens each organization tests for differs (Table 2).

Although crown gall and Pierce's Disease are economically important throughout North America, these diseases are not quarantine regulated and are only monitored by visual inspection of foundation stock. Agrobacterium vitus, the causative agent of crown gall, is widely systemic in state-certified and non-certified grapevine plants but is usually only problematic in viticultural regions of colder climate. Pierce's Disease, on the other hand, is responsible for significant losses throughout the U.S. and particularly in California. Hot water treatment of hardwood cuttings and tissue culture propagation procedures, when integral to the quarantine program, may eliminate these pathogens.

Should incoming grapevine materials be suspected of pathogen contamination, post-entry quarantine programs at FPMS, Davis, California and Agriculture Canada, Sidney, B.C., both offer conventional heat therapy and in vitro shoot tip culture disease elimination capability. These procedures can be completed within six months, but testing of processed materials to determine the success of treatments can take an additional two to three years. It is, there fore, clearly advisable to undertake such treatment in advance of disease assessment if imported plant materials are suspected of contamination. Both procedures can be effective but it is important to weigh the pros and cons of each. Because, for example, vine vigor may be reduced as a result of pathogenic contamination, a clean selection of an infected vine may possess different viticultural qualities. There is no alternative to elimination of quarantinable diseases when bringing new materials into the U.S. When working with contaminated domestic grower selections, however, the decision to eliminate pathogens must be carefully considered.

At the end of the post-entry quarantine period, and provided materials have tested negative for quarantinable diseases, a small number of plants will be released to the importer. To speed up the propagation of selected specimens, it may be possible for the quarantine institution to bulk up materials prior to release upon approval, in anticipation of favorable pathogen test results.

Agriculture Canada, B.C., and FPMS, Davis, California, offer for sale to the public grapevine materials propagated from foundation and non-certified stock plants. The Missouri program is designed for contract importation and release of proprietary materials only.

Regional Grapevine Nursery Certification Programs

At present only California, Missouri, Oregon and Washington State have active nursery certification programs. These statewide certification programs insure that grapevine nursery plants have been derived from correctly-identified clean foundation stock and have been propagated using methods designed to maintain the disease-free status of the material. The certification programs are usually [TABULAR DATA FOR TABLE 3 OMITTED] [TABULAR DATA FOR TABLE 4 OMITTED] controlled by the State Department of Agriculture, and insure that growers purchasing certified stock are accessing the best quality plant material available.

Canada is currently establishing a regionally-based certification program for quality assurance of domestic grapevine nursery stock. Movement of grape stock into or out of the country is regulated by the Plant Protection Division of Agriculture and Agri-Food Canada, a federal organization.

State nursery certification programs are the best indicator of the quality of available plant materials. It should be noted, however, that not all states accept foundation materials generated from third party quarantine programs and that plant materials derived from out-of-state foundation stock may not qualify for state registration. Only plants produced in California and derived from California Department of Food and Agriculture Grapevine Certification program foundation stock plants, for example, are eligible for inclusion within the California program.

Alternative Sources of Grapevine Material and Options for Disease Elimination and Clonal Typing

Many nurseries throughout the U.S. supply certified and/or non-certified grapevine planting material. In addition, the Department of Horticulture at Oregon State University, Corvallis, offers state-certified and non-certified materials derived from foundation vines established when the department possessed a USDA importation permit, or from out-of-state foundation stock plants maintained at the university. Contact Steve Castagnoli for further information and availability: telephone (541) 737-3913.

Several grower or industry selections of commercial varieties are planted in California and other important producing states. These selections may be proprietary or of limited availability, and propagative wood is often transferred from vineyard to vineyard without participation in a state certification program. Examples of high-quality grower selections used within California include the Robert Young, Spring Mountain, Hyde and Wente clones of Chardonnay and the Spottswoode Vineyard clone of Cabernet Sauvignon. Material may be accessed through discussion with particular growers.

Because of elevated interest by growers and nurseries alike in determining or confirming the pathogenic status and identity of grapevine field selections and foundation-derived stock, several organizations now offer independent analytic services. With the development of rapid diagnostic tools, disease assessment turnaround times can be of the order of a few days only.

Independent Diagnostic Services

Table 3 lists those organizations offering disease diagnostic and varietal identification services and products for the grapevine industry.

The organizations identified in Table 3 provide a range of services or products for a wide selection of grapevine applications, listed in Table 4.

As described above, a number of procedures have been developed for determination of the pathogenic status of plant material. The gold standard process for many years, and indeed, still today, is field testing, where material from suspect vines is grafted to woody indicator plants selected because of the disease specific symptoms which develop when they are contaminated with specific pathogens. Although a widely-accepted standard, this procedure is not fool-proof and takes up to three years. New immunological and molecular diagnostic procedures have enabled the development of rapid tests which assay directly or indirectly for the presence of the plant pathogen.

The enzyme-linked immunosorbent assay (ELISA) system relies on detection of the plant pathogen through the immunological reaction of antibodies raised against the pathogen with the disease agent itself (viral or bacterial antigen) present in the candidate plant sap or wood. ELISA technology is most often used for disease status determination by diagnostic laboratories. More accurate disease diagnostic technologies exist or are under development, but are less commonly used because of additional cost and technical complexity.

Polymerase chain reaction technology (PCR), the most accurate technique for plant pathogen identification, is based on detection of genetic material from the pathogen rather than immunological reactions to proteins derived from this genetic material. EuroNursery and Vineyards (West) currently offers PCR-based molecular diagnostic testing for Agrobacterium vitis, the crown gall pathogen, and grapevine virus A and B. Dennis Gonsalves at the Department of Plant Pathology, Cornell University, is currently evaluating a PCR-based test for Rupestris Stem Pitting disease.

Varietal identification services are provided by AgriAnalysis, Davis, California and the Laboratory for Genetic Identification of Fruit and Nut Varieties in the Department of Pomology, University of California, Davis. AgriAnalysis provides rootstock identification services only, while both laboratories use isozyme profile analysis to compare unknown grape-vine samples with known standards. Isozymes, different molecular forms of the same enzyme, are specific to particular varieties, thus providing a tool for use in plant identification. Isozyme analysis is not able to distinguish between clones of the same variety unfortunately, and is only useful for positive identification if known standards are available for comparison.

A number of laboratories worldwide are working on the development of molecular fingerprinting technologies for accurate clonal and varietal identification. Perhaps the most practical application of this technology has been developed by CSIRO Division of Horticulture, Adelaide, Australia, where over 100 varieties and selections of commercially important grapevines have been molecularly characterized. This information has been correlated with clonal, vegetative and grape cluster characteristics, and is accessible over the internet ( For more information contact Mark Thomas at CSIRO, telephone: (011) 61 8 303 8600). Carole Meredith of the Department of Viticulture, University of California, has collaborated with the Australian group and directs her own grapevine genetic fingerprinting research program.

Given the development of new disease diagnostic and clonal typing tools, greater experience with tissue culture-based disease elimination procedures, and heightened industry awareness of the importance of clean planting material, the physiological quality of grapevine material available to the industry has never been greater.


The broadcast advertising of beer and wine won't be on the menu later this month at a congressional hearing on spirits advertising on broadcast media, especially television. Montana Sen. Conrad Burns, according to Advertising Age (Feb. 17) said he wanted to maintain the focus on "distillers and broadcasters," and that by including beer and wine broadcast marketers the "scope of the discussion had gotten too wide."

Spirits marketers, per Ad Age, claimed beer and wine marketers, who didn't have a longtime voluntary ban on broadcast advertising as did spirits marketers, thus had an advantage.
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Author:Stamp, James
Publication:Wines & Vines
Date:Apr 1, 1997
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