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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #242602
Title: First Report of Grapevine leafroll-associated virus-3 in Wine Grape Cultivars in Idaho

Author
item MEKURIA, T - Washington State University
item KARASEV, A - University Of Idaho
item Martin, Robert
item NAIDU, R - Washington State University

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2009
Publication Date: 10/12/2009
Citation: Mekuria, T.A., Karasev, A.V., Martin, R.R., Naidu, R.A. 2009. First Report of Grapevine leafroll-associated virus-3 in wine grape cultivars in Idaho. Plant Disease. 93:1218.

Interpretive Summary: In recent years, wine grape production in Idaho has expanded with approximately 95 percent of the total 1,215 acres of wine grapes grown in the newly designated Snake River Valley appellation. Previous studies have shown that grapevine leafroll disease (GLD) is the most wide spread and economically significant virus disease in wine grapes in Washington and Oregon. However, little was known about the incidence and economic impact of GLD on wine grapes in Idaho. During 2008 growing season, leaf samples were collected from grapevines exhibiting GLD-like symptoms. Six wine grape cultivars (Cabernet Sauvignon, Merlot, Syrah, Petit Syrah, Lemberger and Chardonnay) grown in 10 separate vineyards were represented in the sampling. Petiole extracts from these samples were tested by single-tube reverse transcription-polymerase chain reaction with primers specific for heat shock protein 70 homologue of GLRaV-3. All samples tested positive for GLRaV-3, producing a single band of the expected size of 546 base pairs (bp). An enzyme-linked immunosorbent assay (ELISA) with GLRaV-3-specific antibodies confirmed the presence of the virus in samples that were positive in RT-PCR. GLRaV-3-specific bands were cloned and sequenced. Sequence comparisons suggested four subgroups of GLRaV-3 were present in the Idaho vineyards suggesting multiple introductions of the virus into Idaho.

Technical Abstract: Previous studies have shown that grapevine leafroll disease (GLD) is the most wide spread and economically significant virus disease in wine grapes in Washington and Oregon. However, little is known about the incidence and economic impact of GLD on wine grapes in Idaho. During 2008 growing season, leaf samples from about 25 individual grapevines showing or suspected for GLD symptoms were collected randomly from six wine grape cultivars (Cabernet Sauvignon, Merlot, Syrah, Petit Syrah, Lemberger and Chardonnay) grown in 10 geographically separate vineyards in Canyon County. Petiole extracts from these samples were tested by single-tube reverse transcription-polymerase chain reaction with primers LC 1 (5’-CGC TAG GGC TGT GGA AGT ATT-3’) and LC 2(5’- GTT GTC CCG GGT ACC AGA TAT-3’) specific for heat shock protein 70 homologue (HSP-70 gene) of GLRaV-3 (3). All samples tested positive for GLRaV-3, producing a single band of the expected size of 546 base pairs (bp). An enzyme-linked immunosorbent assay (ELISA) with GLRaV-3-specific antibodies further confirmed the presence of the virus in samples that were positive in RT-PCR. GLRaV-3-specific amplicons were cloned in pCR2.1 (Invitrogen Corp., Carlsbad, CA) and sequenced in both orientations. A pair wise comparison of twenty two sequences (include GenBank accession numbers) showed 87 to 100% identity at the nucleotide level and 92 to 100% identity at the amino acid level. A pair wise comparison of HSP-70 sequences of GLRaV-3 isolates from Idaho with corresponding sequences of GLRaV-3 isolates from GenBank showed nucleotide sequence identities between 88 and 99%. Phylogenetic analysis of HSP-70 sequences from Idaho and GenBank showed clustering into four groups, with 12 sequences in one group, 7 isolates in a second group, one sequence in a third group and 2 sequences in a fourth group. The pattern of clustering indicated no cultivar-specific or vineyard-specific groupings, suggesting separate introductions of different GLRaV-3 isolates into the State vineyards.