贮藏条件对解除休眠水曲柳种子生理特性的影响
[目的]探究贮藏期间水曲柳种子生理指标的变化规律,为水曲柳种子短期干燥贮藏提供理论依据。[方法]以贮藏在-20℃和室温(25℃±2℃)下的含水量 14%水曲柳种子为材料,分别测定种子的电导率、丙二醛、抗氧化酶活性和内源激素含量,选择萌发表现最稳定的含水量 7%种子在-20℃贮藏处理作为对照。[结果]含水量 14%种子在室温下的电导率始终高于其他处理,0 d～180 d 时MDA 含量持续升至4.60 mmol/L,SOD活性呈"S"型变化,GA3/ABA和AsA含量在 30 d～180 d逐渐升高;含水量 14%种子在-20℃下贮藏 90 d～180 d时MDA含量显著下降 19%,SOD活性和GA3/ABA缓慢降低。在-20℃条件下,含水量 7%和 14%种子的电导率、POD活性、CAT活性、IAA/ABA和AsA含量变化规律一致,ZT/ABA呈相反的变化规律。各贮藏阶段,种子的SOD活性与ZT/ABA之间呈显著正相关,POD活性差值与发芽率差值呈显著正相关,ZT/ABA和GA3/ABA之间呈正相关。[结论]含水量 14%水曲柳种子在室温下的活力减弱不会引起 GA3/ABA下降,可能与种子细胞膜透性增加和MDA积累有关,含水量 14%种子在低温下保持高活力可能通过ZT与SOD之间协同作用。
[Objective]To study the changes of physiological indexes of Fraxinus mandshurica seeds during storage,and to provide theoretical basis for short-term drying storage of F.mandshurica seeds.[Method]The electrical conductivity,malondialdehyde,antioxidant enzyme activity and endogenous hormone contents of 14%F.mandshurica seeds stored at-20℃and room temperature(25℃±2℃)were determined,respectively.The 7%seeds with the most stable germination performance were selected as the control.[Result]The conductivity of 14%water content seeds at room temperature was always higher than that of other treatments,MDA content continued to rise to 4.60 mmol/L from 0 d to 180 d,SOD activity showed an"S"type change,and GA3/ABA and AsA content gradually increased from 30 d to 180 d.When seeds were stored at-20℃for 90 to 180 days,MDA content decreased significantly by 19%,SOD activity and GA3/ABA decreased slowly.At-20℃,the electrical conductivity,POD activity,CAT activity,IAA/ABA and AsA contents of 7%and 14%water content seeds showed the same changes,while ZT/ABA showed opposite changes.SOD activity was positively correlated with ZT/ABA,POD activity difference was positively correlated with germination rate difference,and ZT/ABA and GA3/ABA were positively correlated.[Conclusion]The decreased activity of 14%water content seeds at room temperature does not cause the decrease of GA3/ABA,which may be related to the increase of seed cell membrane permeability and MDA accumulation.The high activity of 14%water content seeds at low temperature may be through the synergistic interaction between ZT and SOD.
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