NaCl胁迫对两种冷季型草坪草光合特性的影响

采用盆栽试验方法,研究了不同浓度NaCl(0 mmol/L,35 mmol/L,70 mmol/L,105 mmol/L,140 mmol/L)处理对高羊茅、草地早熟禾光合特性的影响。结果表明:35 mmol/L NaCl处理对2种草坪草的光合特性无明显影响;大于或等于70 mmol/L的NaCl处理,2种草坪草的叶绿素含量、净光合速度(Pn)、蒸腾速度(Tr)、气孔导度(Gs)显著降低,且随NaCl浓度升高,下降幅度增大,但2种草坪草之间的下降幅度有一定差异,高羊茅各指标的下降幅度均小于草地早熟禾。胞间CO2浓度(Ci)的变化,2种草坪草均为低浓度NaCl处理下降低,高浓度NaCl处理下升高。综合叶绿素含量和各项光合指标,高羊茅对NaCl胁迫的耐受能力高于草地早熟禾。

Effects of NaCl Stress on the Photosynthetic Characteristics of Two Cool-season Turfgrass Varieties

The potted planting experiment was used to study the effect of different concentrations of NaCl on the photosynthetic characteristics of Festuca arundinacea, Poa pratensis. The results showed that photosynthetic characteristics of the two turfgrass varieties was not influenced ohvi- ously in 35mmol/L NaCl solution treatment, but their chlorophyll content, Pn, Tr and Gs decreased evidently in 70 mmol/L NaCl solution treatment, and decreased more as the increase of NaCl concentration though the declining values of Festuca arundinacea were a little lower than Poa pratensis. The reducing rate of CO2 concentration between cells sped up along with the increase of NaCl solution for both the turfgrass varieties. The tolerance of Festuca arundinacea to NaCl stress was better than Poa pratensis according to their photosynthetic characteristics and chlorophyll content.