The treatment effect of Paclobutrazol on some effective physiological traits of cold stress tolerance in bud grape of cv. Bidane Sefide

Propose of this study was investigation on the effect of paclobutrazol on physiological parameters of spring buds of grapes. Spraying of paclobutrazol was carried out on cultivar of Bidane Sefide at concentrations of 0, 125, 250, 500 and 1000 mg/L with three replicate contest of the randomized complete block design (CRB) in late buds dormancy in Malayer. Chosen in of proline, malondialdehyde, soluble sugar, total protein, photosynthesis pigments and enzymes activity of peroxidase, polyphenol oxidase and ascorbate peroxidase of buds were measured in spring. Results were shown significant effect of paclobutrazol on parameters of proline, soluble sugar, total protein and mentioned enzymes. Treatment of 500 mg/L had the most effect on reduced of malondialdehyde levels (with 13% decrease compared to the control) and increased the activity of peroxidase, polyphenol oxidase and ascorbate peroxidase (with 563, 478, 407 decrease compared to the control, respectively). Due to the effects of these parameters on determining tolerance to environmental stresses, concentration of 500 mg/L was determined as best concentration to improve the adaptability of buds for late cold spring tolerance