水杨酸对华北落叶松种子萌发及幼苗生理特性的影响

Effect of salicylic acid on seed germination and seedling physiological characteristics of Larix principis-rupprechtii Mayrn

【目的】研究水杨酸（SA）对华北落叶松种子萌发和幼苗生长的影响,为水杨酸在华北落叶松育苗中的科学应用提供理论依据。【方法】采用SA浸种和外施2种方式,设置0.1,0.5和1.0mmol/L 3个SA浓度处理华北落叶松种子,以蒸馏水处理为对照,在25℃培养条件下分析SA对华北落叶松种子萌发和幼苗SOD、POD活性及MDA、可溶性糖含量的影响,并比较培养温度为25,30和35℃时,各处理幼苗POD、SOD活性以及MDA和可溶性糖含量的差异。【结果】SA浸种可以显著提高华北落叶松种子的发芽率,以0.1mmol/L处理最高,发芽率为87.22%,0.5mmol/L处理次之,对照发芽率仅为54.02%;0.1mmol/L SA处理的胚根长度较对照提高83.91%,胚芽长提高84.67%,0.5mmol/L处理次之,但对胚芽长的提高作用不显著;0.1mmol/L SA浸种处理在30和35℃下的POD活性分别较对照提高3.59%和174.42%,SOD活性分别较对照提高86.98%和109.82%,而外施SA处理幼苗的POD和SOD活性在30℃下分别较对照提高217.82%和128.15%,35℃条件下分别提高56.77%和277.67%;30和35℃条件下,0.1mmol/L SA浸种处理幼苗的MDA含量分别较对照降低17.72%和7.32%,外施SA处理分别降低12.94%和11.10%;0.1和0.5mmol/L SA处理幼苗的可溶性糖含量均显著高于对照。【结论】在SA处理后的12d内,0.1~0.5mmol/L的SA对促进华北落叶松胚根、胚芽生长和提高幼苗SOD、POD酶活性及降低MDA含量效果较佳。

[Objective] This study investigated the effect of salicylic acid （SA） on Larix principisrupprechtii seed germination and seedling growth to improve the application of SA in Larix principisrupprechtii nursery. [Method] Soaking and exogenous applications of SA were used to process Larix principis rupprechtii seed with 3 concentrations （0.1,0.5,1.0 mmol/L）. Water was used as control and temperature was 25 ℃. The effects on seed germination, activities of POD and SOD and contents of MDA and soluble sugar of each treatment were analyzed and their differences at temperatures of 25,30,and 35 ℃ were compared. [Result] SA soaking significantly improved the germination rate of Larix principis-rup- prechtii. 0.1 mmol/L treatment showed the highest rate of 87. 22% ,followed by 0.5 mmol/L treatment, the control only 54.02%. The radicle and germ lengths were increased by 83.91% and 84.67% with 0. 1 mmol/L SA followed by 0.5 mmol/L. 0.1 mmol/L SA seed soaking improved POD and SOD activities by 3.59% and 86.98% at 30 ℃ and by 174.42% and 109.82% at 35 ℃,while exogenous application of SA improved POD and SOD activities by 217.82% and 128.15% at 30 ℃ and by 56.77% and 277.67% at 35 ℃ followed by 0.5 mmol/L treatment. Soaking treatment decreased MDA content by 17. 72% and 7.32% while exogenous SA treatment decreased MDA content by 12.94% and 11.10% at 30 and 35 ℃,respectively. Soluble sugar contents treated with 0.1 and 0.5 mmol/L SA were significantly higher than the control. [Conclusion] Within 12 days of seed treatment, 0. 1-0. 5 mmol/L SA was better to improve the growth of radicle and germ,increase SOD and POD activities and decrease MDA content.