OENO One (Dec 2000)
New contribution to the survey of the theory of the acrotony on the branch of one year grapevine: II - Influence of growth regulators on bud burst carried by one eye cuttings in post-dormancy stage
Abstract
Investigation of the Tunisian vineyard showed that on long canes of Muscatel of Italy, a certain percent of growing branches presents both the acrotony and basitony phenomena. The discussion of the investigation results allowed us to define a new hypothesis according to which these phenomena are controlled in part by a hormonal balance. In order to test this hypothesis, we are proceeded by studying the influence of growth regulators on bud bursting carried on one eye cuttings in one hand and on long canes to 10 units cultivated in greenhouse and in the laboratory on the other hand as well as on long wood in the vineyard. We report in this work the results relative to one eye cuttings. We applied an immersion of buds carried by one eye cuttings and in phase of post-dormancy, during 24 hours in different growth regulators at different concentrations (GA3 50 mg/l, 25 mg/l, 12.5 mg/l; ABA 25 mg/l, 12.5 mg/l, 6.25 mg/l; 6BAP 50 mg/l, 25 mg/l, 12.5 mg/l; Kinétin 50 mg/l, 25 mg/l, 12.5 mg/l; AIA, AIB, ANA 50 mg/l, 25 mg/l, 12.5 mg/l; 2-4D 10 mg/l, 5 mg/l, 2.5 mg/l). Results of these treatments show that there are generally some inhibitory effects for gibberellins and auxins. In the contrary, cytokinins possess the stimulate effects of bud bursting, applied during the end of the post dormancy phase. The interesting conclusion concerning the interaction of two growth regulators resides especially in the interaction cytokinin-auxins. According to our results auxins possess some inhibitory effects on the bud bursting, on the contrary, cytokinins possess a stimulate effect. The Interaction cytokinin-auxin seems to attenuate the negative effect of auxins on the bud bursting. We will see subsequently that differed applications of these regulators can give a clear demonstration.
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