盐胁迫下大气CO2浓度升高对黄瓜幼苗生长、光合特性及矿质养分吸收的影响

采用营养液培养和开顶箱法,研究了盐胁迫下CO2浓度升高对黄瓜幼苗生长、光合特性及矿质养分吸收的影响。结果表明,黄瓜生长在80mmol/L NaCl下,其生物量、光合速率、气孔导度、蒸腾速率均显著下降,而胞间CO2浓度明显升高;CO2浓度升高可增加盐胁迫下黄瓜幼苗生物量,使光合速率、气孔导度、蒸腾速率升高。表明CO2浓度升高能减轻盐胁迫对光合功能的不利效应。80mmol/L NaCl可使黄瓜幼苗体内总N和K 的浓度降低,而使Na 浓度增加;CO2浓度升高具有提高盐胁迫下总N和K 浓度,降低Na 浓度的效应,说明CO2浓度升高可减轻盐胁迫的毒害作用,提高黄瓜幼苗生物量。

Effects of elevated CO2 concentration on growth, photosynthetic characteristics and mineral elements of cucumber seedlings under salt stress

Cucumber was hydroponically cultured to study the effects of elevated CO2 concentration on the growth,photosynthetic characteristics and mineral elements of cucumber seedlings under salt stress.The results indicated that the biomass,net photosynthetic rates,stomatal conductance and transpiration of cucumber seedling grown in 80 mmol/L NaCl decreased compared to the control,while intercellular CO2 concentration increased.However,under NaCl stress,elevated CO2 concentration enhanced the biomass,net photosynthetic rates,stomatal conductance and transpiration of cucumber seedling compared to that at ambient CO2 concentration.The results indicated that the unfavorable effects of salt stress on photosynthetic functions could be alleviated by high CO2 concentration.80 mmol/L NaCl reduced total N and K content,and enhanced Na content of cucumber seedling.However,under salt stress,elevated CO2 concentration increased total N and K content,and decreased Na content of cucumber seedling,indicating that elevated CO2 concentration alleviated salt stress on cucumber seedling and enhanced biomass of cucumber seedling.