碱胁迫对宁夏枸杞叶中Na＋，K＋，Ca2＋动态变化的影响

摘要：为探讨宁夏枸杞叶中离子平衡与盐碱胁迫的关系，研究不同浓度的NaHCO3溶液胁迫下，枸杞叶中Na^＋，K^＋，Ca^2＋的浓度变化，同时采用非损伤微测技术研究了枸杞叶中Na^＋，K^＋，Ca^2＋的流速变化．结果表明，在同一时间内（7，14，21d），Na^＋的浓度随NaHCO。浓度的升高总体呈升高趋势，K^＋和Ca^2＋的浓度总体呈下降趋势，c（Na^＋）／c（Ca^2＋）随NaHCO3浓度的升高而升高；随着时间的变化，各个处理下枸杞叶中Na^＋的浓度总体呈现先降后升的趋势，K^＋的浓度总体呈现下降趋势，Ca^2＋的浓度总体呈现先升后降的趋势，c（Na^＋）／c（K^＋）总体呈现升高趋势，c（Na^2＋）／c（Ca^2＋）总体呈现先降后升的趋势；NaHCO。溶液胁迫7d时，诱导了枸杞叶肉细胞中净Na^＋，K^＋，Ca^2＋外排的增加．碱胁迫下造成c（Na^＋）／c（K^＋）和f（Na^＋）／c（Ca^2＋）升高的原因为，叶片中K^＋和Ca^2＋外排和Na^＋大量积累，这也是枸杞不耐碱的原因之一．可为种植枸杞改良盐碱地提供参考．

Effects of Alkaline Stress on Dynamic of Na+,K+ and Ca2+ Ions in Lycium barbarum L.

To better understand the relationship between salt-alkaline and ions balance of Lycium barbarum L.,using the ion-selective electrode technique and the atomic absorption spectrophotometry,fluxes of Na+,K+ and Ca2+ were investigated in mesophyll cells and Na+,K+ and Ca2+ concentrations obtained with a pot experiment.The results showed that Na+ concentrations and Na+:Ca2+ratio increased and K+ and Ca2+ concentrations decreased with the NaHCO3 concentration increasing in one time(7 d,14 d and 21 d).Meanwhile,Na+ content and Na+:Ca2+ ratio firstly decreased and then increased,K+ concentrations decreased,Ca2+ firstly increased and then decreased and ratio of Na+ and K+ increased with the long term stress.Compared to controlling,the Lycium barbarum L mesophyll cells exhibited a higher capacity to extrude Na+ and K+ and Ca2+ after 7 days exposure to 300 mmol/L NaHCO3.In conclusion,under alkaline stress,the significant increase in the mesophyll of Na+,K+ and Ca2+ efflux and the accumulation of Na+ resulted in increased ratio of Na+ and K+ and ratio of Na+ and Ca2+,which was one of the reasons that Lycium barbarum L.show weak ability to alkali stress.