|Discovery of a novel Grapevine vein clearing virus isolate in wild Vitis rupestris vine|
M. KOVENS (1), L. Hubbert (1), S. Honesty (1), Q. Guo (1), D. Pap (1), R. Dai (1), L. Kovacs (1), W. Qiu (1). (1) Missouri State University, Springfield, MO, U.S.A.
Grapevines are infected by over 60 different viruses. <i> Grapevine vein clearing virus </i>(GVCV) is associated with a severe vein clearing and vine decline disease that severely affects grape production and berry quality in Midwest vineyards. Symptoms include translucent vein-clearing, backward rolling, and chlorosis of the leaves as well as short, zig-zagged internodes and a decline of vine vigor. The genome sequence of GVCV-CHA that was isolated from grape cultivar ‘Chardonel’ in a commercial vineyard was published in 2011. It has a circular dsDNA genome of 7,753 bp, and encodes three open reading frames (ORFs) with four short ORFs within the intergenic region. A new isolate of GVCV, referred to as GVCV-VRU, was identified in a wild <i>Vitis rupestris</i> vine in its native site in the southwest region of Missouri. GVCV-VRU associated symptoms are necrotic flecks along major veins in <i>V. rupestris</i>. Comparative analysis of GVCV-CHA and GVCV-VRU found that GVCV-VRU genome is two base pairs longer than GVCV-CHA genemoe and thyey shared 91.5% identical nucleotides. ORF II is the most variable region with a 9 bp insert only present in GVCV-VRU genome; GVCV-VRU and GVCV-CHA share only 83.3% nucleotide identity. The discovery of a new GVCV isolate in wild grapevine provides important clues on the evolution and epidemics of GVCV.