Rootstock effects on the reaction of grafted cypress to Seiridium cardinale bark canker disease

Knowledge of rootstock effects on the reaction of grafted cypresses to bark canker disease induced by Seiridium cardinale, as well as a knowledge of cypress growth parameters, could play an important role in the production of resistant clones. Auto-, homo- and heteroplastic grafts were carried out by using self-rooted ramets of 4 cypress clones in all combinations. Self-rooted ungrafted ramets obtained from the 4 rootstock clones were used in the same test. All 4-year-old trees were measured for total height and diameter before artificial inoculation. Rootstock clones had no statistical influence on the diameter of grafted trees, but did significantly affect total height. Correlations among these growth traits and disease scores were non-significant. A statistically significant tendency for rootstocks to transfer their own canker susceptibility or resistance level to the grafted ramets did not, however, modify the resistance class into which the grafted clones had been previously classified.