Ameliorative Effects of Paclobutrazol on Vegetative and Physiological Traits of Grapevine Cuttings under Water Stress Condition

摘要

Under water stress conditions, both vegetative and reproductive parts of the grape are equally affected. The aim of the present investigation was to assess the interaction of paclobutrazol (PBZ) and water stress on {Vitis vinifera L. 'Shiraz'). The treatments contained: a) irrigation in two levels, field capacity moisture condition (FC) and 40% of FC; and b) PBZ application, at 250, 500 and 1000 mg/L. PBZ interacted with water stress and contributed to reduction of leaf area, internode and shoot length. Leaf chlorophyll content that was reduced as a result of drought was mitigated by PBZ. Similar to water stress, PBZ increased proline content in leaves. Higher doses of PBZ could increase the level of shoot protein content in the both irrigation regimes. Even though water stress caused a reduction in relative water content (RWQ of leaves, PBZ could overcome this effect. Drought caused a reduction in both fresh and dry weights of the vine shoots and roots, comparing to the controls. PBZ could confront the reduction effects of water deficiency on root and shoot fresh weight and shoot dry weight. From the above findings it can be concluded that under water stress conditions, use of PBZ could be useful to overcome the impacts of water deficiency.