赤霉素和弱酸对鳗草种子萌发和生理特性的影响

Effects of gibberellin and weak acid on seed germination and physiological characteristics of the eelgrass Zostera marina

中文关键词: 赤霉素  萌发率  种子休眠  营养物质  鳗草

英文关键词: Gibberellin  Germination rate  Seed dormancy  Nutrients  Zostera marina

中文摘要:

      本文研究了赤霉素和弱酸对鳗草(Zostera marina)种子萌发和生理特性的影响，监测了鳗草种子的累积萌发率、幼苗建成率以及种子萌发过程中种子干重、水分、呼吸速率、可溶性糖、淀粉、赤霉素、脱落酸含量和α-淀粉酶、β-淀粉酶活性的动态变化，探究了2种外源处理对鳗草种子的促萌作用，分析了鳗草种子应对外源促萌的生理响应过程。结果显示，2种促萌处理均能有效促进鳗草种子萌发和幼苗建成，其中，赤霉素处理组促萌效果最优，其种子萌发率和幼苗建成率为对照组的1.6倍；促萌期间，2个促萌处理组种子α-淀粉酶活性呈先上升后下降的趋势，淀粉含量呈下降趋势，可溶性糖含量呈持续上升趋势；至实验结束时，赤霉素处理组种子可溶性糖含量最高，是促萌前初始值的3.3倍，亦显著高于弱酸处理组和对照组(P<0.05)，弱酸处理组种子淀粉含量最低，显著低于其他2组(P<0.05)，而各处理组之间种子的α-淀粉酶活性无显著差异(P>0.05)；主成分分析显示，种子α-淀粉酶活性、淀粉和可溶性糖含量为种子萌发过程中的关键因子。综合分析认为，外源赤霉素处理是破除鳗草种子休眠的有效方法，其主要通过调节种子淀粉酶活性、提高淀粉分解速率和提高可溶性糖含量为种子萌发提供能量实现破除休眠的作用。本研究结果为鳗草种子快速萌发技术提供了理论依据和科学基础。

英文摘要:

      The effects of gibberellin and weak acid on the germination and physiological characteristics of eelgrass (Zostera marina) seeds were studied under laboratory conditions. The cumulative seed germination and seedling establishment rates were calculated. The dynamic changes in seed dry weight, water content, respiration rate, soluble sugar, starch, gibberellin, abscisic acid content, and α-amylase and β-amylase activities during seed germination were monitored. The effect of two exogenous germination-promoting treatments on seed germination was explored, and the physiological response process of the seeds to these treatments was analyzed. The results showed that the treatments effectively promoted seed germination and seedling establishment. The gibberellin treatment had the best germination-promoting effect, and the seed germination and seedling establishment rates were 1.6 times higher than those under the control. During the germination period of seeds in the two treatments, the α-amylase activity first increased and then decreased, the starch content showed a downward trend, and the soluble sugar content continued to increase. At the end of the experiment, the soluble sugar content of seeds in the gibberellin treatment attained the highest value, which was 3.3 times higher than the value before germination and was significantly higher than that in the weak acid treatment and control (P<0.05). The starch content of seeds in the weak acid treatment attained the lowest value, which was significantly lower than that in the other two treatments (P<0.05). There was no significant difference in α-amylase activity among the treatments (P>0.05). Principal component analysis showed that α-amylase activity and starch and soluble sugar contents of seeds were the key factors in seed germination. Comprehensive analysis showed that exogenous gibberellin treatment was an effective method to break seed dormancy. This effect was mainly achieved by regulating amylase activity, increasing starch decomposition rate, and increasing soluble sugar content to provide energy for seed germination. The results provide a theoretical and scientific basis for the rapid germination technology of eelgrass seeds.