外源水杨酸对盐胁迫下茶树生长及主要生理特性的影响

Effects of exogenous salicylic acid on growth and physiological characteristics of tea plant(Camellia sinensis)under salt stress

【目的】研究外源水杨酸(Salicylic acid,SA)对盐胁迫下茶树生长及主要生理特性的影响,探索其缓解盐胁迫的生理机制。【方法】采用盆栽试验,以茶树品种"龙井长叶"为材料,在40mmol/L NaCl胁迫处理下,叶面喷施不同浓度(0,0.5,1.0,1.5mmol/L)外源SA,研究其对茶树生长及主要生理特性的影响。【结果】盐胁迫下,喷施不同浓度外源SA均可不同程度提高茶树叶片相对含水量(RWC),降低水分饱和亏(WSD),增加植株鲜质量和干质量;增加脯氨酸和可溶性蛋白含量,提高超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,抑制过氧化氢酶(CAT)活性,降低丙二醛(MDA)含量和电解质渗透率。本试验条件下以1.0mmol/L SA处理效果最佳。【结论】外源SA可通过提高渗透调节和抗氧化能力,维持植株水分平衡,保护膜结构和功能,缓解盐胁迫对茶树的伤害,从而促进茶树生长。

[Objective] The effects of exogenous salicylic on growth and physiological characteristics of tea plant （Camellia sinensis） under salt stress were investigated to explore physiological mechanisms of salt stress relief. [Method] ＂Longjingchangye＂ was used as the materials to study effects of exogenous salicylic acids with different concentrations （0,0.5,1.0,and 1.5 mmol/L） on growth and physiological characteristics of tea under 40 mmol/L NaC1 stress with foliar spray. [Result] Exogenous salicylic acid improved relative water content （RWC） and decreased water saturation deficit （WSD） in leaves and increased fresh weight and dry weight of tea plant. It also increased contents of proline, soluble protein, enhanced activities of superoxide dismutase （SOD） and peroxidase （POD）,and decreased CAT activity malondialdehyde （MDA） content and electrolyte leakage in various degrees. The optimum treatment concentration was 1.0 mmol/L in this study. [Conclusion] Salicylic acid alleviated the harm of salt stress and promoted tea plant growth by improving osmotic regulation, anti-oxidation, water balance, and membrane stability.