NaCl单盐胁迫对不结球白菜叶片光合特性的影响

Effects of salt stress on photosynthetic characteristics of Pak-Choi

为探讨NaCl胁迫对不结球白菜光合特性的影响,以不结球白菜‘苏州青’为试材,采用营养液水培的方法,研究了不同浓度NaCl(0,50,100,150,200mmol·L^(-1))对不结球白菜幼苗叶片叶绿素含量、光合参数、荧光参数的影响。结果表明,盐胁迫降低了不结球白菜叶片中光合色素含量;使不结球白菜的净光合速率、气孔导度、蒸腾速率、最大光化学效率显著下降;PSⅡ有效光化学量子产量(Yield)、电子传递效率(ETR)、水分利用效率(WUE)、胞间CO_2浓度(Ci)、光化学猝灭系数(qP)呈下降趋势,非光化学猝灭系数(qN)呈上升趋势。其中100mmol·L^(-1)的NaCl浓度对不结球白菜的抑制程度最大,这表明盐胁迫能显著影响不结球白菜的相关光合指标,且随着NaCl浓度的增加,不结球白菜受到的胁迫损伤不断加重。

The effect of different salt treatment on chlorophyll content photosynthetic characterists and cholorophyll fluorescence was studied in Pak-Choi variety ＇Suzhouqing＇ as the tested material by hydropnic culture. The results showed that the cholorphyll content was decreased in non-heading cabbage with walt stress. The net photosynthetic rate （Pn）, stomatal conductance （Gs）, transpiration rate （Tr）, photosystem Ⅱ （Fv/Fm） was decreased significantly. And effective photochemical quantum yield （Yield） and electron transport rate （ETR） were also significantly decreased. Water use efficiency （WUE） and coefficient of photochemical quenching （qP） were slightly lower; intercellurlar carbon dioxide concentration （Ci） and non-photochemical quenching coefficient （qN） were significantly increased. The results indicated that there were significant effects on photosynthetic characteristics under salt stress and these parameters showed greater change under salt stress than that under root salt stress.