2000 Volume 69 Issue 2 Pages 171-175
Fifteen rose rootstocks which were cultured and propagated in vitro were inoculated with the strain GOU1 of Agrobacterium tumefaciens as a test for resistance to the crown gall disease. Rosa multiflora and R. multiflora 'K2' were highly susceptible, 95% and 90% of the stems forming large tumors, 6.61 and 3.62 (mm×mm), respectively. Three varieties of R. canina, 'Pfander', 'Superbe', and 'Brogs Stachellose', and a native one became infected but formed small tumors (0.5mm×mm). In R. rugosa and R. canina 'Superbe' 40% of the infected shoots formed tumors during the first week after inoculation. Thus, these species have a low resistance to tumor formation, whereas R. virginiana formed no tumor during the first week after inoculation ; 73% of the shoots produced tumors 3 weeks after inoculation. Therefore, R. virginiana is subject to infection but resistant to tumor formation.
