Susceptibility of Grape-vine Rootstocks to Strains of Agro bacterium tumef aciens biovar 3

Abstract

Forty grape-vine rootstocks were inoculated with five strains of Agrobacterium tumefaciens biovar 3 in a field trial. Grape-vine material like Paulsen 775 was immune to all strains whereas Kober 125 AA, Freedom, 3309 C, Harmony, Solonis, 101-14 Mgt., Berlandieri 13/5 and Kober 5BB appeared to be resistant. Jacquez, US 2-1, US 24-23, Muscat d' Alexandrie and US 24-10 were the most susceptible. Host range differences occurred among the five strains of A. tumefaciens on the different rootstock cultivars. Five different host range patterns were evident. A. tumefaciens biovar 3 strain 1771 was the most virulent and strain 2221 was the least virulent of the strains used.

Profiling of Disease-Related Metabolites in Grapevine Internode Tissues Infected with Agrobacterium vitis

“…Previously, the crown gall resistance locus ( Rcg1 ) was found in the genome of V. amurensis (Kuczmog et al, 2012), but subspecies of V. amurensis show variable degrees of resistance against different A. vitis isolates (Ferreira and van Zyl, 1986; Stover et al, 1997; Szegedi et al, 1984). V. flexuosa is an East-Asian grapevine species with high resistance to crown gall disease (Szegedi et al, 1984); however, it was susceptible to A. vitis , forming large galls with high GIs in our study.…”

“…Responses of grapevine species (cultivars) to the crown gall pathogen infection were examined at 60 days after inoculation based on the crown gall development, which was estimated by gall severity (GS) index (GSI) that was evaluated by gall incidence (GI) and gall diameter (GD) index (GDI) as GI × GDI that was 0 = 0.0 (no gall), 1 = 0.1–1.5 mm, 3 = 1.5–5.0 mm, and 5 = above 5 mm of GD (Ferreira and van Zyl, 1986), and expressed as averages and standard deviations of 11–22 replications depending on the number of shoot cuttings used for the Vitis species tested. The plant responses were classified into different response types based on GI, GD, and GSI of Vitis species into RR (low GI and small GD), SR (high GI and small GD), and SS (high GI and large GD), respectively, based on significant differences in GSI at P ≤ 0.05 by Tukey’s honest significant difference (HSD) test, corresponding to resistant, moderately resistant, and susceptible plant responses to the bacterial infection, respectively.…”

“…Values are presented as number or mean ± standard deviation of 11–22 replications depending on Vitis species.GI, gall incidence; GD, gall diameter; GSI, gall severity index.*National Clonal Germplasm Repository ID, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Davis, CA, USA.†GSI = GI × GD index that was 0 = 0.0 (no gall), 1 = GD of 0.1–1.5 mm, 3 = GD of 1.5–5.0 mm, 5 = GD of over 5.0 mm (Ferreira and van Zyl, 1986). …”

“…†GSI = GI × GD index that was 0 = 0.0 (no gall), 1 = GD of 0.1–1.5 mm, 3 = GD of 1.5–5.0 mm, 5 = GD of over 5.0 mm (Ferreira and van Zyl, 1986). …”

Susceptibility of Some Grapevine Cultivars and Rootstocks to Crown Gall Disease

“…Galls usually occur on the trunk just above the ground line, although aerial galls up to 1 m above the soil have been observed (Mahmoodzadeh, 2002). Also, A. vitis has been found in vineyards but not in nonvineyard soils (Burr & Katz, 1984;Ferreira & Van Zyl, 1986). When field soils are assayed for the presence of Agrobacterium spp., non-tumorigenic strains are often predominant (Burr et al, 1987).…”