VIEW ARTICLE

Techniques

Development of a Polymerase Chain Reaction Technique for the Detection of Grapevine Fanleaf Virus in Grapevine Tissue. Adib Rowhani, Plant pathology specialist, Department of Plant Pathology, University of California, Davis 95616; C. Chay(2), D. A. Golino(3), and B. W. Falk(4). (2)(3)(4)former graduate student, USDA-ARS research plant pathologist, and professor, respectively, Department of Plant Pathology, University of California, Davis 95616. (2)Present address: USDA-ARS, Cornell University, Ithaca, NY 14853. Phytopathology 83:749-753. Accepted for publication 25 February 1993. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/Phyto-83-749.

A polymerase chain reaction (PCR) method has been developed to detect grapevine fanleaf virus (GFLV) in GFLV-infected grape tissue. Four sample extraction methods for infected plant tissues were compared. Although PCR could readily detect RNA in samples of GFLV RNA and virion in GFLV-infected leaf samples of Gomphrena globosa with all four extraction methods, only one method was useful for GFLV detection in grapevine tissue. Dilution of infected grape leaf samples by a 200-fold excess of healthy leaf tissue did not prevent GFLV detection by this method. Extracts from healthy grapevines prepared by methods 1, 2, and 3 prevented detection of extracted GFLV genomic RNAs by PCR, demonstrating that grape tissue extracts can inhibit either reverse-transcriptase reactions or PCR. Using method 4, GFLV could be detected in all tested cultivars of European grape, Vitis vinifera, and an American species, V. rupestris. Detection was possible in infected leaves, shoots, roots, and bark scrapings. PCR detection of as little as 128 fg of GFLV RNA was possible.