Hot-water treatment of dormant grape cuttings: Its effects on <i>Agrobacterium tumefaciens</i> and on grafting and growth of vine

Authors

  • C. Bazzi
  • E. Stefani
  • R. Gozzi
  • T. J. Burr
  • C. L. Moore
  • F. Anaclerio

DOI:

https://doi.org/10.5073/vitis.1991.30.177-187

Keywords:

crown gall, Agrobacterium tumefaciens, variety of vine, rootstock, cane, shoot, callus, latent infection, thermotherapy, growth, mortality

Abstract

Hot-water treatment (50°C for 20-30 min) was carried out to confirm its efficacy in eradicating Agrobacterium tumefaciens biovar 3 (AT3) in symptomless grape cuttings.
After the forcing period, analyses of callus from cuttings of grape cvs Albana, Lambrusco Grasparossa, Rulander and Fortana, and from their graft combinations with the rootstocks 420A, 41B, 5BB and 1103P, revealed the low infection level in the grape material used. Dormant scion and rootstock cuttings treated identically in the U.S. gave similar results. Despite this, it was possible to confirm the efficacy of thermotherapy in eradicating the pathogen.
An assessment was also made of the effect of treatment on growth parameters of grafted vines in the greenhouse and after 8 months in a field nursery. The effect of hot-water treatment on the vitality and growth of vines varied with the different scion-rootstock combinations. Treatment did not generally have detrimental effects on vitality; there were some negative effects on graft-take. The number and length of canes, as well as the diameter of the trunks, increased in most instances.
The treatments and times usually did not affect bud survival and, in most cases, increased the level of callus formation at the base of cuttings.

 

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Published

2015-10-22

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