Abstract
Background: Vegetation restoration is a main ecological remediation technology for greening saline and alkaline soils. The objectives of this study were to determine whether aminobenzotriazole (ABT), a rooting powder, can be used to improve the physiological regulatory abilities of Tamarix chinensis under salt stress; to reveal the physiological regulatory pattern by which T. chinensis pre-treated with ABT adapts to salt stress. Results: (1) As the salt stress level increased, the cutting survival rate, height, and root length of T. chinensis gradually decreased, whereas their biomass first decreased and then increased. At salt content（ S c）>0.9%, cutting propagation of T. chinensis was difficult, and there was a considerable decrease in its biomass. The effectiveness of ABT in improving the survival rate and growth of T. chinensis cuttings became increasingly pronounced as the salt stress level increased. (2) T. chinensis was found to adapt to salt stress through increased Chl content. However, excess salt stress inhibited Chl synthesis. ABT can be used to widen the range of tolerance of T. chinensis seedlings to salt stress during Chl synthesis. (3) T. chinensis can eliminate excess reactive oxide species (ROS) by enhancing SOD and POD activities. An excess accumulation of ROS will impede the increase in enzyme activities. ABT can help improve T. chinensis seedling enzyme system regulation and was found to be most effective at a concentration of 100 mg·L -1 . (4) ABT can reduce MDA accumulation and damage caused by membrane lipid peroxidation (MLP). ABT at a concentration of 100 mg·L -1 was found to be highly effective in reducing MDA content. Conclusions: ABT was effective in improving the survival rate and the growth and physiological regulatory abilities of T. chinensis cuttings under salt stress. ABT enhanced the resistance of T. chinensis to salt stress. However, under high S c (>0.9%) and ABT concentration (>100 mg·L -1 ) conditions, the physiological regulatory ability of T. chinensis seedlings exposed to salt stress weakened. At S c of 0.9%, T. chinensis seedlings pre-treated with ABT at 100 mg·L -1 exhibited the most vigorous growth, highest biomass, and highest physiological and biochemical regulatory abilities.
Effects of Exogenous Melatonin on the Physiological Characteristics of Kiwifruit Hayward under Salt Stress
