Author
KARTHIKEYAN, G - WASHINGTON STATE UNIV | |
MEKURIA, T - WASHINGTON STATE UNIV | |
Martin, Robert | |
NAIDU, R - WASHINGTON STATE UNIV |
Submitted to: Phytopathology
Publication Type: Abstract Only Publication Acceptance Date: 5/21/2008 Publication Date: 6/1/2008 Citation: Karthikeyan, G., Mekuria, T., Martin, R.R., Naidu, R.A. 2008. Molecular variability of Grapevine leafroll associated virus-1 in the Pacific Northwest vineyards. Phytopathology. 98: S57. Interpretive Summary: Technical Abstract: Grapevine leafroll disease (GLD) is the most economically important viral disease in the Pacific Northwest. Grapevine leafroll-associated virus-1 (GLRaV-1) is one of six GLRaVs documented so far in the region. A study was undertaken to determine molecular variability of GLRaV-1 collected from two wine grape and two ornamental grape cultivars. A 398 nucleotide (nt) fragment specific to the coat protein duplicate 2 (CPd2) was amplified from eight GLRaV-1 isolates by reverse transcription-polymerase chain reaction (RT-PCR). In addition, a 633 nt fragment of the open reading frame 9 (ORF 9), located towards the 3’ end of the virus genome, was amplified by RT-PCR from the two ornamental grape cultivars. The CPd2- and ORF 9-specific amplicons were cloned and sequenced, and the sequences compared among themselves and with corresponding sequence of GLRaV-1 isolate from Australia (GenBank accession number AF195822). The CPd2 sequences showed nucleotide sequence identity between 93 and 99% and amino acid sequence identity between 91 and 100% among the eight GLRaV-1 isolates. However, these isolates showed 85-88% nucleotide sequence identity and 80-84% amino acid sequence identity with the corresponding CPd2 sequence of an Australian isolate. ORF 9 sequences from the two ornamental grapes showed 98% identity among themselves at both nucleotide and amino acid level and 88% identity with the Australian isolate at both nucleotide and amino acid level. These results suggest genetic diversity among GLRaV-1 isolates from the Pacific Northwest region and indicate their differences with GLRaV-1 isolate from Australia. Additional data on sequence variation in other genomic regions of GLRaV-1 will be presented. |