安徽农业科学

为了优化冷凉地区樱桃萝卜栽培技术，通过外源喷施水杨酸(SA)探究其对冷凉环境下幼苗的生理调控机制。结果表明，SA处理通过双重路径影响幼苗生长：积极作用方面，0.010和0.030 mmol/L SA显著激活超氧化物歧化酶(SOD)活性(提升幅度达27.11%和33.91%),0.005～0.030 mmol/L SA抑制丙二醛(MDA)积累(降幅28.43%～45.25%),维持细胞膜结构稳定性，同时促进抗坏血酸(V_C)合成(增幅49.17%～107.16%),有效缓解低温引起的氧化损伤；负面影响方面，SA抑制叶绿素b合成(降幅达35.92%),降低水分利用效率(0.010～0.030 mmol/L SA WUE下降超过77%)。SA浓度效应呈现阈值特性：0.005 mmol/L SA处理显著提升净光合速率(P_n增加49.58%),而浓度大于0.010 mmol/L时则产生抑制作用(P_n下降41.66%～100%)。尽管脯氨酸、可溶性糖等渗透调节物质未发生显著变化，但干物质积累与SOD活性呈正相关。0.005 mmol/L为SA喷施的最佳处理浓度，其通过平衡气孔调控(气孔导度提升207%)与光合代谢，有效维持细胞抗氧化能力，激活抗氧化系统缓解冷凉胁迫，有效提高樱桃萝卜的抗冷能力。说明适宜浓度的SA处理对樱桃萝卜在冷凉环境下的生长具有积极调控作用。

To optimize the cultivation techniques for cherry radish in cold environments, the physiological regulatory mechanisms of exogenous salicylic acid(SA) application on seedlings under cold stress was investigated. The results indicated that SA treatment influenced seedling growth through dual pathways: Positively, 0.010 and 0.030 mmol/L SA significantly activated superoxide dismutase(SOD) activity(increased by 27.11%和33.91%), inhibited malondialdehyde(MDA) accumulation(decreased by 28.43%-45.25%) by 0.005-0.030 mmol/L, maintained cell membrane stability, and promoted ascorbic acid(Vc) synthesis(increased by 49.17%-107.16%), effectively alleviating oxidative damage caused by low temperatures. Negatively, SA inhibited chlorophyll synthesis(decreased by 35.92%), reduced water use efficiency(0.010-0.030 mmol/L SA reduces WUE by over 77%). Notably, the concentration effect of SA exhibited a threshold characteristic: 0.005 mmol/L treatment significantly enhanced the net photosynthetic rate(P_n increased by 49.58%), while concentrations above 0.010 mmol/L had inhibitory effects(P_n decreased by 41.66%-100%). Although osmotic regulators such as proline and soluble sugars showed no significant changes, dry matter accumulation was positively correlated with SOD activity. This study identified 0.005 mmol/L as the optimal concentration for SA application, which balanced stomatal regulation(stomatal conductance increased by 207%) and photosynthetic metabolism, ensuring carbon assimilation while effectively maintaining cellular redox homeostasis and activating the antioxidant system to mitigate cold stress.This approach significantly improved the cold resistance of cherry radish, but strict control of SA concentration is necessary to avoid adverse effects.