文冠果种子吸水和萌发对盐碱胁迫条件的响应

Response Xanthoceras sorbifolia Bunge seeds germination and water salinity stress conditions

[目的]研究文冠果种子对盐碱生境的适应能力。[方法]对文冠果种子进行12组（盐分含量,分为0.2%、0.5%、0.8%3种梯度）不同盐、碱浓度的胁迫处理,分析文冠果种子的吸水和萌发特征。[结果]研究表明：种子萌发0~6h期间吸水速率最快,12~42h较稳定,54~114h吸水速率放缓,在盐胁迫和重度盐碱混合胁迫下,吸水速率明显受到抑制,其他条件下均大于对照组。在轻度胁迫和碱胁迫下,种子萌发率高于对照,其他胁迫条件下,发芽率降低明显,其中0.8%浓度（NaCl∶Na_2SO_4=9∶1）胁迫下种子发芽率最低,仅为对照的14.63%,差异极显著（P〈0.01）。轻度胁迫和碱胁迫对文冠果种子萌发有促进作用,混合胁迫和高浓度胁迫对种子萌发有明显的抑制作用。[结论]本试验通过研究文冠果种子的吸水和萌发特,为采用外源措施提高种子吸水能力,促进种子萌发和出苗奠定基础。

[Objective]To explore the adaptability of Xanthoceras sorbifolia Bunge seeds to saline-alkali habitat.[Method]We exposed Xanthoceras sorbifolia Bunge seeds to different concentration of salt and alkali solution（calculated as salt concentration,three gradients of 0.2%,0.5% and 0.8%）,and analyzed the water absorption and germination characteristics of the seeds.[Results]Results showed that,during their germination,the water absorption rate within0-6hours was fastest,relatively stable within 12-42 hours,and slower for 54-114 hours.However,the water absorption rate under salt and severe salt-alkali mixture stress was significantly restrained,while the water absorption rate under the other conditions was greater than that of control.The seed germination rate under mild salt and alkali stress was higher than that of control,whereas the germination rate under the other stress conditions was reduced significantly,reaching a minimum under the concentration of 0.8%（NaCl∶Na_2SO_4=9∶1）,only 14.63% of control（very significant difference,P〈0.01）.Mild salt and alkali stress promoted Xanthoceras sorbifolia Bunge seeds germination,and high concentration of stress and salt-alkali mixture stress markedly inhibited seeds germination.[Conclusion]This study will lay the foundation for using exogenous measures to improve seed water absorbing ability and promote seed germination and seedling emergence.