CHARACTERIZATION OF GRAPEVINE LEAFROLL-ASSOCIATED VIRUS 4 FROM INDIAN VINEYARDS

In a 2013-15 survey, typical symptoms of grapevine leafroll disease were observed in vineyards of Western and North-Eastern India. Twelve grapevine cultivars were infected with Grapevine leafroll-associated virus 4 (GLRaV-4), as shown by ELISA. The coat protein (CP), heat shock protein 70 homologue (HSP70h) and p23 genes of GLRaV-4 isolates from India were characterized by RT-PCR and sequencing. A phylogenetic analysis of the CP gene showed that the Indian isolates clustered with GLRaV-4 isolates Y252-IL (AM162279) from Israel, Y253-TK (AM176759) from Turkey, and LR106 (FJ467503) from USA with a maximum identity of 98% at the amino acid level. Sequences analysis revealed intra- and inter-species recombination events within CP and p23 genes of GLRaV-4 isolates. Indian isolates GRP-G (KT759152) and GDR-I (KT759153) diverged from other GLRaV-4 isolates in their p23 gene. This is the first report of the occurrence of GLRaV-4 in Indian vineyards and of recombination in the GLRaV-4 genome.