effect of salicylic acid on the proline, soluble sugars and ion leakage in two apricot cultivars under cold stress

in order to study the effect of different concentrations of salicylic acid in two commercial apricotcultivars of shahrood namely ‘shahrood 41’ and ‘jaffari’, under cold stress, a factorial experiment wasconducted in a randomized complete block design with three replications in 2012 at the agriculturalresearch center of shahrood city. the test had four factors including: sa with three levels (0.625, 0.125,0.25mm), three stages of phenological growth (dormancy, swelling and flowering) and four temperature(four, zero, -2 and -4 degree centigrade) and two apricot cultivars (‘shahrood 41’ and ‘jaffari’) andmeasured traits were proline and soluble sugars. ‘jaffari’ cultivar had the highest amount of solublesugars at -4 degree centigrade in bud swelling stage and the maximum rate of proline belonged to0.25mm of sa in the same cultivar, -4 degree centigrade and bud swelling stage. ion leakage at differenttemperatures and different phonological growth stages were significantly different at five percent level.‘jaffari’ with lower ion leakage at -4 degree and higher proline content than ‘shahrood 41’ had higherresistance to frost.