seasonal changes in soluble proteins, total phenol and malondialdehyde content and their relationship with cold hardiness of some grapevine cultivars

screening of native cultivars and understanding of the mechanisms involved in cold hardiness in grapevines is needed to match cultivars appropriately with growing sites and aid in breeding and selecting cultivars with improved freezing tolerance. in this study cold hardiness of fifteen grapevine (vitis vinifera l.) cultivars were evaluated using tetrazolium stain test and post freezing budbreak assays during six months from acclimation till deacclimation stages. moreover, seasonal changes pattern in soluble proteins, total phenol and malondialdehyde (mda) of buds were measured during this period. significant differences (p≤0.01) were found among cold hardiness of cultivars in all stages. ‘bidaneh ghermez’ and ‘khalili’ (lt50= -22 and -22.6 ºc in respectively) were the hardiest ‘ruby’ and ‘perlette’ (lt50= -16.1 and –16.9 ºc in respectively) were the least hardy cultivars in january. soluble proteins and total phenol concentrations of buds increased during cold acclimation from november to january then decreased in march. the concentration of these compounds was higher in cold hardy such as ‘bidaneh ghermez’ and ‘khalili’ cultivars than least hardy ones, indicating the positive relationship of these compounds with freezing tolerance. the measured mda in onset and end of dormancy period was lower than its concentration in deep dormancy in january. lower mda concentration was found with cold hardy cultivars ‘khalili’ and ‘bidane ghermez’ in comparison with cold sensitive cultivars, ‘perlette’ and ‘yaquti’. our results indicated that high accumulation of soluble proteins and total phenol in cold hardy cultivars resulted in improved membrane stability and freezing tolerance.