GENOMIC STUDY AND DETECTION OF A NEW VARIANT OF GRAPEVINE RUPESTRIS STEM PITTING ASSOCIATED VIRUS IN DECLINING CALIFORNIA PINOT NOIR GRAPEVINES
M. Lima , R. Alkowni, J.K. Uyemoto, A. Rowhani
doi: 10.4454/jpp.v91i1.636
Abstract:
Declining cv. Pinot noir clone 23 plants on 3309 Couderc rootstock were observed in different vineyards in California exhibiting severe stunting, solid red leaves and rootstocks with stem necrosis-distortion. High molecular weight dsRNA of ca. 8.7 kbp was extracted from symptomatic vines, used as a template for cDNA libraries construction and sequencing and identified as a new strain of Grapevine rupestris stem pitting-associated virus designated as Pinot noir strain (GRSPaV-PN). Molecular characterization of GRSPaV-PN genome revealed that the complete nucleotide sequence was composed of 8,724 nt, excluding the poly-A tail. This strain shared nucleotide identity of 76% to 78% with other GRSPaV sequences present in the GenBank. Its genome organization included six open reading frames where its replicase gene had 76% and 85% nucleotide and deduced amino acid identities, respectively, to other GRSPaV sequences. The coat protein gene was the most conserved with nucleotide and amino acid identities of 81-88% and 91.8-95%, respectively. Limited field survey revealed that GRSPaV-PN was present mainly in Pinot noir clone 23. However, the causal nature of GRSPaVPN and 3309C stem necrosis-distortion is not known. Keywords: GRSPaV-PN, detection, RT-PCR, rugose
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