Issue link: http://winesandvines.uberflip.com/i/513570
VIEWPOINT June 2015 WINES&VINES 33 But there are costs associated with adher- ence to tests and methodologies that date back to the 1950s and '60s, predating the genetic revolution. ELISA and DNA testing methodol- ogy has steadily increased in scope and reli- ability, and it offers a lower cost alternative to woody indexing. Furthermore, the additional option of deep sequencing will minimize the chances that any viruses will escape detection. In this era of financial constraints, can we af- ford not to consider moving forward with such changes? Importation and development of new plant material involves both state and federal regula- tions, and testing methods are written into the current regulations. Changing those to accom- modate new technology and improved meth- ods is an enormous barrier. It won't be easy to do so. The relevant question is this: Have molecu- lar technologies advanced to the extent that they offer scope of detection, performance and repeatability comparable to or better than that obtained through woody indexing? Are they reliable enough to minimize false negatives or positives? The answer to these questions will require careful analysis of accessions and samples that have been through both types of tests. It is a task that is an ongoing effort of clean plant centers and an appropriate task for the Na- tional Clean Plant Network. Several clean plant centers have started to make the relevant com- parisons, and results to date are encouraging. For example, Al Rwahnih et al. (in press) at the University of California, Davis' Foundation Plant Services found next-generation sequenc- ing to be more effective in identifying key grapevine viruses than woody indexing. Simi- lar efforts are under way with other crops. It's time for open discussion among regula- tors, scientists and industry about the pros and cons of modernizing methods and regula- tions in the face of rapid evolution in testing methodology. While a prime consideration is maintaining or improving upon current stan- dards, the costs of a two- to four-year delay involved with woody indexing—and the ben- efits of reducing that lag time—should be an equally important criterion. The potential savings in time and expense are too large to ignore. Tim Martinson, Ph.D., is senior viticulture extension associate in the School of Integrative Plant Science's Department of Horticulture at Cornell University. He also serves as director of the Northern Grapes Project. Cor- nell virologists Marc Fuchs and Keith Perry also con- tributed to the article. REFERENCES Al Rwahnih, M.; S. Daubert; D. Golino; C. Islas, and A. Rowhani. In Press. "Comparison of Next Genera- tion Sequencing vs. Biological Indexing for the Optimal Detection of Viral Pathogens in Grapevine," Phytophathology. Hannah, L.; P. Roehrdanz; M. Ikegami; A. Shepard; M. Shaw; G. Tabor; L. Zhi; P. Marquet, and R. Hijmans 2014. "Climate change, wine, and conservation." Proceedings Natl. Acad. Sci. 110 (17), 6907-6912. White, M.; N. S. Diffenbaugh; G. V. Jones; J. S. Pal, and F. Giorigi. 2006. "Extreme heat reduces and shifts United States premium wine production in the 21st century." Vol. 103, No. 30, 11217-11222. The option of deep sequencing will minimize the chances that any viruses will escape detection.