盐碱胁迫对油菜苗期生理及光合特性的影响

Effects of Saline-Alkali Stress on Physiology and Photosynthetic Characteristics of Rape Seedlings

以"华油杂62号"油菜为试材,采用盆栽方法,研究了复合盐碱胁迫对"华油杂62号"油菜苗期生理及光合特性的影响,以期为油菜在盐碱地的种植提供参考依据。结果表明:复合盐碱胁迫下,油菜幼苗叶片中可溶性糖、脯氨酸含量在重度处理时显著低于轻度处理,且苗后期含量高于苗前期;其可溶性蛋白质含量在苗前期中、重度处理显著高于轻度处理,且苗后期低于苗前期。油菜幼苗叶片中保护酶活性有不同程度的降低趋势,但各处理间差异不显著,且超氧化物歧化酶(SOD)、过氧化物酶(POD)活性在苗后期低于苗前期,过氧化氢酶(CAT)活性在苗后期高于苗前期。随着盐碱程度增大,油菜幼苗净光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、气孔导度(Gs)均呈现出先降低后升高的趋势。复合盐碱胁迫对油菜苗期渗透调节物质(可溶性糖、脯氨酸、可溶性蛋白质)含量、酶(SOD、POD、CAT)活性以及光合参数(净光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、气孔导度(Gs))具有抑制作用,且随着盐碱程度的增大,抑制作用增强;油菜苗前期抑制程度大于苗后期,在苗后期油菜光合能力减弱,体内酶活性降低,但其可通过合成渗透调节物质来适应逆境。

‘Huayouza 62’was used as the test material,and the potting method was used to study the effect of compound saline-alkali stress on the seedling physiology and photosynthetic characteristics of‘Huayouza 62’rape,in order to provide a theoretical basis for the cultivation of rape in saline-alkali land.The results showed that under the compound saline-alkali stress,the soluble sugar and proline content in the leaves of rape seedlings were significantly lower in the severe treatment than in the mild treatment,and the content in the late seedling stage was higher than that in the early stage;the soluble protein content was moderate to severe in the early stage The treatment was significantly higher than the light treatment,and the late seedling stage was lower than the early seedling stage.The protective enzyme activities in the leaves of rape seedlings decreased to varying degrees,but the differences were not significant among the treatments.The activities of SOD and POD were lower than those of the pre-emergence stage in the late seedling stage,and the activity of CAT was higher than that of the pre-emergence stage in the later seedling stage.As the salinity increased,the net photosynthetic rate(Pn),transpiration rate(Tr),intercellular CO2 concentration(Ci),and stomatal conductance(Gs)of rapeseed seedlings all showed a trend of decreasing first and then increasing.Compound saline-alkali stress on the content of osmotic adjustment substances(soluble sugar,proline,soluble protein),enzyme activity(SOD,POD,CAT)and photosynthetic parameters(net photosynthetic rate(Pn),transpiration rate(Tr),intercellular CO2 concentration(Ci),stomatal conductance(Gs))had an inhibitory effect,and as the degree of salinity increases,the inhibitory effect was enhanced;the degree of inhibition in the early stage of rapeseed was greater than that in the late stage of seedling,and the photosynthetic capacity of rapeseed was weakened in the late stage of seedling,enzyme activity in the body was reduced,but it could adapt to adversity by synthesizing osmotic adjustment substances.