盐胁迫对谷子幼苗生长及光合特性的影响

以豫谷17为材料,选取中性盐Na Cl、Na2SO4以及碱性盐Na HCO33种盐,分别设置0(CK)、0.2%、0.4%3种土壤盐含量梯度,研究了盐胁迫对谷子幼苗生长和光合特性的影响,以期为不同盐碱地的谷子栽培提供理论依据。结果表明:随着土壤盐含量的升高,叶片SPAD值降低,叶片净光合速率、气孔导度和蒸腾速率下降,胞间CO2浓度先降低再升高,其中,SPAD值受Na Cl影响最大,0.2%、0.4%处理下分别比CK下降24.1%、34.0%;净光合速率受Na2SO4和Na HCO3影响较大,0.2%、0.4%处理下分别比CK下降47.8%、80.2%和38.9%、85.5%;在中性盐胁迫下,谷子幼苗叶片水分利用效率随土壤盐含量升高表现为先上升后降低,而在碱性盐胁迫下则表现为下降;谷子幼苗株高和干物质积累量在Na Cl胁迫下随盐含量增加而降低,而在Na2SO4和Na HCO3胁迫下则表现为低含量促进、高含量抑制,其中,干物质质量在土壤盐含量0.4%时受Na HCO3影响最大,较CK下降37.0%。因此,Na2SO4和Na HCO3含量较低的轻盐碱地较Na Cl含量较低的轻盐碱地更适合种植谷子,Na2SO4和Na HCO3含量较高的重盐碱地不适合种植谷子。

Effect of Salt Stress on Growth and Photosynthetic Characteristics of Foxtail Millet Seedlings

In order to provide theoretical foundation for millet cultivation in different saline-alkali land, the growth and photosynthetic characteristics of millet seedlings ( Yugu 17 ) were studied under different salt stress. Three kinds of salt were used in this study ( NaCl and Na2 SO4 as neutral salt, NaHCO3 as alkaline salt) with three concentrations(0% as CK, 0. 2% and 0. 4%). The results showed that with the increase of salt concentration, the leaf SPAD value, net photosynthetic rate, stomatal conductance and transpiration rate increased,intercellular CO2 concentration decreased first and then increased. The SPAD value was severely affected by NaCl treatment,which decreased by 24. 1% and 34. 0% under 0. 2% and 0. 4% concentration treatments compared with CK. However, the Na2 SO4 and NaHCO3 treatment influenced the net photosynthetic rate most,which decreased by 47. 8%,80. 2% and 38. 9%,85. 5%under 0. 2%,0. 4% Na2SO4 and NaHCO3. Under neutral salt stress,the water use efficiency(WUE) of seedling leaf increased first and then decreased,and the WUE of seedling leaf decreased under alkaline salt stress as the salt concentration elevated. The height and dry matter accumulation of seedlings decreased as the NaCl concentration increased,which however,increased first and then decreased with the elevation of Na2 SO4 and NaHCO3 concentration. Particularly,the dry matter accumulation of seedlings was most impacted by NaHCO3 when the salt concentration was 0. 4%, which decreased by 37. 0%. To conclude,it was more suitable for millet cultivation in saline-alkali land with low Na2 SO4 and NaHCO3 concentration than that with low NaCl concentration,while cultivation of millet in saline-alkali land with high Na2 SO4 and NaHCO3 concentration was not recommended.