Effect of Phytoregulatory Substances on Adventitious Rooting of Grapevine Rootstock Paulsen 1103 Cuttings Under Hydroponic Conditions

In the present study, the propagation ability of rootstock 1103 Paulsen in a hydroponic system was investigated. In the first part of the experiment, the effects of indolebutyric acid (IBA), dopamine (L-DOPA), and their combination on rhizogenesis were examined. The experiment was conducted under controlled conditions in a hydroponic system. Key parameters evaluated included rooting percentage, average root diameter, average number of roots per cutting, total root area, total root length, and moisture content of the cuttings. Results showed that L-DOPA treatment, followed by the IBA + L-DOPA combination, exhibited the most favorable outcomes across these parameters. The hydroponic system proved highly effective for root formation compared to other substrates (e.g., peat, perlite, sand, or their combinations), provided that continuous aeration of the water was ensured for adequate oxygenation. The second part of the experiment focused on the response of phenolic compounds, antioxidants, sugars, and starch in woody cuttings subjected to different treatments (control, IBA, L-DOPA, and IBA + L-DOPA) and how these compounds varied over time. The objective was to assess the influence of the treatments on both the rhizogenesis process and the biochemical profile of the cuttings throughout the experiment. This research aims to contribute to the understanding of the rooting behavior of 1103 Paulsen in hydroponic systems and to evaluate the physiological and biochemical responses of cuttings under different treatments.