Elimination of the Crown Gall Pathogen, Agrobacterium vitis, from Systemically Infected Grapevines by Tissue Culture

Abstract

Agrobacterium vitis causes crown gall, a serious disease of grapevines that is common in grape growing regions worldwide. Tissue culture approaches were previously tested for elimination of the bacterium from grapevines, but the detection methods for assessing their effectiveness were much less sensitive than the recently developed magnetic capture hybridization real-time PCR. The latter method was applied in this study to evaluate the elimination of A. vitis from cuttings propagated from severely crown gall-diseased Vitis vinifera cv. Riesling vines by dissecting and culturing apical and axillary buds, as well as meristems, from shoot tips and micropropagating them in tissue culture to recover plantlets. Although the distribution of A. vitis in infected mother vines varied greatly, apparently bacteria-free meristematic tissues were successfully used for the establishment of vines for which bacterial populations were undetectable, even after a dormancy period. It is anticipated that the production and use of clean grapevines in vineyards will delay the early onset of crown gall and contribute to vineyard productivity.