摘要
试验研究盐胁迫下宁夏枸杞盐分与甜菜碱及光合作用的动态变化结果表明,9～12g/kg NaCl胁迫下枸杞叶片由下向上逐渐发黄脱落,生长严重受抑,0.8～6g/kg NaCl胁迫下枸杞下部叶片仅个别出现发黄萎蔫现象,生长未严重受抑,随盐处理浓度增加和胁迫时间的延长,枸杞叶片中Na^+、Cl^-含量呈持续增加趋势。而0.8～9g/kgNaCl胁迫下甜菜碱呈增加趋势,12g/kg NaCl胁迫下甜菜碱呈先升后降趋势。由于Na^+、Cl^-大量积累,枸杞叶片光合作用总体呈下降趋势,0.8～6g/kg NaCl胁迫下光合速率下降主要受气孔限制,而PSⅡ光化学活性却保持较强稳定性。但>6g/kg NaCl胁迫下光合速率下降是因Na^+、Cl^-大量积累对光合酶产生直接的毒害作用,使非气孔限制因素成为主要限制因子,同时PSⅡ光化学活性受到损伤。枸杞叶片对Na^+、Cl^-的积累呈现先快后慢趋势,而甜菜碱则随胁迫时间的延长大量积累,枸杞叶片内甜菜碱大量积累是宁夏枸杞抗盐的重要生理原因之一。
Effects of NaCl on concentrations of salt ions and glycinebetaine and photosynthesis of salt-tolerance Lycium barbarum L. are determined. The results show that leaf burn sysnptoms are very serious under NaCl stress of 9-12g/kg concentration, and slight under its concentration of 0.8-6g/kg. With the increasing of NaCl concentration and the prolongation of days of treatment, the contents of Na + and Cl- are accumulated gradually. As to the NaCl concentration, the rate of photosynthesis of Lycium barbarum L. gradually decreases. When the concentration of NaCl is 0.8-6g/kg, the photosynthesis of Lycium barbarum L. leaf is decreased, which is caused mainly by the decrease of stomatal conductance. On the contrary, when the concentration of NaCl is more than 6g/kg, the photosynthesis is decreased yet. The main cause is that the photosynthetic enzyme is damaged by surplus Na + and Cl accumulated in the Lycium barbarum L. leaf, therefore, the non-stomatal limitation becomes the main factor, decreasing seriously the photosynthesis and PS II photochemical efficiency. Accumulations of Na+ and Cl- show a trend from quick to slow, while betaine is accumulated excessively. The accumulation of betaine is also contributed to the salt resistance of Lycium barbarum L.
出处
《中国生态农业学报》
CAS
CSCD
2003年第3期51-54,共4页
Chinese Journal of Eco-Agriculture
基金
国家重点基础研究(973)发展规划项目(G1999011705)
