Author
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: Mekuria, T., Martin, R.R., Naidu, R.A. 2008. The occurrence of a distinct variant of Grapevine fanleaf virus in Washington State vineyards. Phytopathology. 98:S68. Interpretive Summary: Technical Abstract: Grapevine fanleaf virus (GFLV, genus: Nepovirus, family: Comoviridae), is one of the most important viral diseases of wine grapes (Vitis vinfera) worldwide. During our reconnaissance studies, samples from the wine grape cultivar Chardonnay collected in two separate vineyards tested positive for GFLV in RT-PCR using primers specific to the coat protein. Sequence analysis of the 322 base pair amplicon showed 89-91% identity with corresponding sequences of GFLV isolates in GenBank. Additional analysis by enzyme-linked immunosorbant assay was positive for GFLV antibodies. These results confirmed the presence of GFLV in vineyards in Washington. The virus was found as mixed infection with Grapevine leafroll-associated virus (GLRaV)-3 in one vineyard and with GLRaV-1, GLRaV-3 and Grapevine virus A in the other vineyard. The RNA2 from one GFLV isolate was characterized by cloning and sequencing RT-PCR amplified DNA fragments. The cloned fragments covered 3564 nucleotides (nt) of the RNA2 and showed 90% sequence identity with GFLV strain F13 from France. The genetic organization of RNA2 revealed a single polyprotein of 1190 amino acids with 90% sequence identity to the corresponding sequence of GFLV isolates from different parts of the world. The three RNA2-encoding proteins showed 74-79% (2AHP), 88-90% (2BMP) and 88-90% (2CCP) identity at the nucleotide level and 75-78% (2AHP), 95-96(2BMP) and 94-96% (2CCP), at the amino acid level with corresponding sequences of GFLV isolates from different parts of the world. These results indicate the presence of a distinct GFLV isolate in Washington State vineyards. |