Evaluating some apple rootstocks in boron toxicity condition using morpho-‎physiological and biochemical indexes in soil

This trial was conducted in order to evaluating nine apple rootstocks including MM106, M26, Ottawa3, Suporter4, M9, M7, P22 , MM111 and local rootstock "Gamialmasi" in different levels boron (0, 15, 30, 45 and 60 mg/kg soil). Results indicated that height rootstock, LAI, wet and dry weight leaf, chlorophyll index, WRC and vegetative growth rate reduced in comparison control as increased boron soil in all rootstocks. Vegetative growth ceased in all rootstocks, exception M26 and P22. Also, ion leakage and MDH increased as raised boron level in soil. Ascorbate peroxidase and super oxide dismutase leaf activity increased at first and then decreased with increasing boron levels in soil. Based on leaf analysis, leaf boron concentration in M26 and P22 was less than other rootstocks. Vegetative, physiological and biochemical assessments showed that M26 and P22 were more tolerate in relation other rootstocks.