Grapevine Cuttings as Potential Sites of Survival and Means of Dissemination ofAgrobacterium tumefaciens

Abstract

A. tumefaciens (AT) biovar 3 and (to a lesser extent) biovar 1 were detected in symptomless 1-yr-old grape cane cuttings taken from crown gall-infected vines, thus indicating their systemic nature. With selective media, both biovars were isolated from callus and small roots of surface-sterilized cuttings rooted in a sterilized potting mixture. Pathogenic strains were recovered from the cultivars Gewurtztraminer, Pinot Chardonnay, Pinot Noir and White Riesling. The pathogen was not detected in canes taken from apparently healthy vines. AT biovar 3 was recovered from one of 10 soil samples collected around trunks and roots of vines with crown gall symptoms.