苏铁耐旱、抗寒及光合生理特性研究

采用干旱胁迫及人工模拟冷冻试验 ,进行苏铁耐旱、抗寒及光合生理特性研究 ,结果表明 :不同年龄苏铁的耐旱性、抗寒性及光合生理指标存在明显差异 ,随苏铁叶龄增加 ,苏铁叶片水势、冻害敏感指数和 NR活力下降 ,蒸腾速率、自然饱和亏和叶绿素含量增加 ,苏铁耐旱及抗寒性增强 ;苏铁水分及光合生理指标对干旱胁迫反应敏感 ,随干旱胁迫加剧 ,苏铁叶片水势、蒸腾速率、叶绿素、NR活力及净光合速率下降 ,而自然饱和亏增大 ,以适应胁迫环境 ,使苏铁表现出较强的抗旱性和生命力。

STUDY ON PHYSIOLOGICAL CHARACTERS OF DROUGHT RESISTANCE,COLD RESISTANCE AND PHOTOSYNTHESIS OF CYCAS REVOLUTA

The physiological characters of drought resistance, cold resistance and photosynthesis were studied through the experiments of water stress and artificial simulated cold. The results are as follows: there are significant differences among physiological characters of drought resistance, cold resistance and photosynthesis of different aged Cycas revoluta. As the age of Cycas revoluta increases, its water potential, sensitive index to cold and nitrate reductase activity decrease, while transpiration rate, W.S.D. and chlorophyll content increase , the drought resistance and cold resistance enhance. The responses of Cycas revoluta under water stress are sensitive. As water stress increases, its water potential, transpiration rate, chlorophyll content, nitrate reductase activity and net photosynthetic rate decrease, while W.S.D. increases. Therefore, Cycas revoluta show highly drought resistance and life.