VIRUS COMPOSITION INFLUENCES VIRUS ELIMINATION SUCCESS AND IN VITRO GROWTH CHARACTERISTICS OF THE GRAPEVINE cv PLAVAC MALI
K. Hancevic, G. Zdunic, D. Voncina, T. Radic
Shoot tip cultures coupled with thermotherapy was used for the production of virus- free candidate clones of the Croatian autochthonous and most important red-berried grapevine cultivar Plavac mali. The procedure was successful for the elimination of Grapevine leafroll- associated virus 3 (GLRaV-3) and Grapevine fleck virus (GFkV), but not Grapevine leafroll- associated virus 1 (GLRaV-1). Results showed that a selective virus eradication occurred depending on the initial composition of the viral population of treated samples. When the in vitro growth of cv. Plavac mali explants harbouring different viruses was compared, it was found that, similarly to virus elimination, tissue proliferation was virus composition- dependent. This is a first report on virus elimination in cv. Plavac mali and, by and large, from grapevines in Croatia.