Cutting is the most common method of vegetative propagation. A critical step in this process is the initial development of a functional root system. The anatomical structure of the cutting has been shown to affect the rooting ability of some species, but for grapevines this has not yet been investigated. The aim of this work was to evaluate the rooting ability of Vitis cuttings, with emphasis on the anatomical aspects. The four cultivars studied were: Vitis labrusca L. cv. Bordô, V. rotundifolia Michx. cv. Topsail and hybrid rootstocks of V. berlandieri Planch. × V. riparia Michx., 'Kobber 5BB' and 'SO4'. Of these cultivars, only 'Topsail' showed poor rooting ability; 77 days after planting the cuttings, poor rooting ability of cv. Topsail was observed in relation to the other three cultivars. A high percentage of live cuttings was observed, but they did not take root. There were no calluses on this cultivar. These data may indicate the presence of endogenous factors in cv. Topsail that make it difficult for cuttings to take root. The anatomical features of the base of the cv. Topsail cutting were different from those of the other cultivars in that they retained the fiber bundles of the primary phloem, and they also had reduced secondary phloem with radial fiber bands. Therefore, rooting difficulty in this cultivar may be related to anatomical barriers.
grapevines; cuttings; adventitious roots; anatomy
