2000 Volume 66 Issue 1 Pages 29-34
Shoots of nine rose cultivars, including cut roses and rootstocks, were inoculated in vitro with four strains of Agrobacterium tumefaciens to test their resistance. Disease incidence of susceptible R. canina and R. canina ‘Pfänder’ was 61% and 85%, respectively. Disease incidence of ‘PEKcougel’ and ‘Lifirane’, with strong resistance to tumor formation, was under 17%. GOU1 caused disease on the most cultivars, with over 73% disease incidence on six roses, with the exceptions of ‘Bridal Pink’ ‘Lifirane’ and ‘PEKcougel’. A208, G-Ag-27, C58clrif-R were weakly virulent, except against R. canina ‘Pfänder’. ‘Dukat’, ‘Fashion Parade’ and R. coriifolia froebelii were susceptible to GOU1, but not to G-Ag-27 and C58clrif-R. Tumors were largest in ‘Lifirane’, and statistically smaller in the other roses. The tumors induced by C58clrif-R were larger than those induced by the other strains.