PT - JOURNAL ARTICLE AU - R. N. Goodman AU - R. Grimm AU - M. Frank TI - The Influence of Grape Rootstocks on the Crown Gall Infection Process and on Tumor Development AID - 10.5344/ajev.1993.44.1.22 DP - 1993 Jan 01 TA - American Journal of Enology and Viticulture PG - 22--26 VI - 44 IP - 1 4099 - http://www.ajevonline.org/content/44/1/22.short 4100 - http://www.ajevonline.org/content/44/1/22.full SO - Am J Enol Vitic.1993 Jan 01; 44 AB - Stem tissue explants from greenhouse grown-rootstock, 5C, SO4, 5BB, 8B, and 125AA were inoculated with Agrobacterium tumefaciens. Rootstock 5C was, by far, the most tumorigenic. Twenty-five clones of the five rootstocks and of rootstock 3309C from nurseries in Switzerland, Germany, and Italy were examined for the presence of A. tumefaciens in their vascular fluids. The greatest number rootstock pieces containing virulent populations of the pathogen was 5C. The formation of large, soft, and friable callus at the base of grafted 5C rootstock pieces during the heat-callusing process appears to provide ideal sites of penetration by the pathogen and the opportunity for transformation of grape cells and subsequent tumor development. The data suggest that 5C is an inordinately sensitive host to A. tumefaciens. As a consequence, its use in replanting vineyard sites where spring frosts are likely is hazardous.