硅对盐胁迫下金丝小枣叶绿素荧光参数和气体交换的影响

以2年生嫁接苗为试材,研究了硅对盐胁迫下金丝小枣光合生理的影响。结果表明:金丝小枣在含3.0和5.0 g/kg NaCl土壤中生长135 d,叶绿素(Chl)含量分别降低12.30%和22.08%,加硅比不加硅Chl含量分别提高9.26%和10.62%;光系统 II(PSII)的潜在化学活性(Fv/Fo)和最大光化学效率(Fv/Fm)分别下降19.96%,34.58%和 8. 86%, 14. 10%,加硅比不加硅 Fv/Fo 和 Fv/Fm 分别提高 32. 25%, 30. 71%和11.26%,12.15%;光合速率(Pn)和气孔导度(Gs)分别下降 11.04%,25.32%和 26.13%,16.22%,加硅比不加硅Pn和Gs 分别提高10.94%,20.87%和42.68%,10.85%。说明盐胁迫下给土壤施硅可缓解盐离子对金丝小枣光合作用的抑制与伤害。

Effects of Silicon on Chlorophyll Fluorescence and Gas Exchange of Zizyphus jujuba cv. Jinsi-xiaozao Under Salt Stress

Effects of silicon addition on chlorophyll fluorescence and gas exchange of Zizyphus jujuba cv.Jinsi-xiaozao under salt stress were studied by using 2-year-grafted seedlings.Ordinary agronomic soil was selected as pot-cultured medium.Sources of sodium and silicon for experiment were sodium chloride and potassium silicate.Soil salt contents(NaCl) were planned 3 levels,i.e.0 g/kg,3.0 g/kg and 5.0 g/kg.Soil silicon (Si) contents were planned (2 levels),i.e.0 g/kg and 0.4 g/kg.The experimental results showed that the growth in soils containing 3.0 g/kg or 5.0 g/kg NaCl for 135 d salt ions had distinctively negative effects on jisi jujube plants:Chlorophyll content decreased by 12.30% and 22.08% respectively compared with none-salt stress,while silicon addition increased chlorophyll content by 12.30% and (22.08%) respectively compared with under the two salt stresses;Fv/Fo and Fv/Fo of PSII,two important chlorophyll fluorescence parameters,decreased by 19.96%,(34.58%) and 8.86%,(14.10%) respectively,while increased 32.25%,30.71% and 11.26%,12.15% respectively under silicon addition;photosynthetic rate and cellular conductance decreased by 11.04%,25.32% and 26.13%,(16.22%) respectively,while increased 10.94%,(20.87%) and 42.68%,10.85% respectively under silicon addition.The results revealed the silicon addition ameliorated salt toxicity,osmotic stress and nutrition deficit on Z.jujuba cv. jinsi-xiaozao plant under salt stress.