D.P. de Vries, L. A.M. Dubois
Contrary to new cultivars, breeding of rose rootstocks is not undertaken. As the limit of yield of cultivars has been reached, further progress may be expected from improved rootstocks. Rootstocks significantly affect the yield of scion varieties; shoot yield of combination plants is a useful parameter of rootstock-induced vigour; yield of own-rooted cultivars is commonly lower than on a rootstock; scion-rootstock interaction as to vigour is not present in the rose. As Edelcanina (seedling) stocks show genotypical variation for induced vigour, clonal stocks are preferred.

Important part of mode of action of rootstocks is breaking the quiescence of axillary buds of the scion variety in various stages of plant development. The vigour of genotypes is graft-transmittable. In seggregating seedling populations, the individual vigour of genotypes may be assessed on the basis of number of shoots and shoot length of plants of the same age.

de Vries, D.P. and Dubois, L. A.M. (1992). THE BREEDING OF CLONAL ROSE ROOTSTOCKS.. Acta Hortic. 320, 97-104
DOI: 10.17660/ActaHortic.1992.320.13

Acta Horticulturae