外源甜菜碱和脯氨酸对盐胁迫下大麦种子萌发及幼苗生长的影响

为探讨盐胁迫条件下外源甜菜碱（GB）和脯氨酸（Pro）对不同大麦品种种子萌发及幼苗的效应，以课题组前期筛选到的耐盐品种中川大麦和盐敏感品种ZY218为材料，在萌发期和苗期以200 mmol·L^-1NaCl为胁迫条件，分别施加浓度为0、0.5、1.0、5.0、10.0 mmol·L^-1的外源GB和浓度为0、5.0、15.0、30.0、45.0 mmol·L^-1的外源Pro进行处理，测定并分析了不同处理下大麦萌发及幼苗相关指标。结果表明，与不添加外源物质的对照相比，施加外源GB和Pro均可有效缓解盐胁迫对大麦种子萌发及地上部分生长的抑制作用；提高叶片过氧化物酶（POD）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性及叶绿素含量；外源Pro可以显著增加幼苗的总根长、总根体积和总根表面积，有效缓解盐胁迫对大麦幼苗根系生长的抑制作用，且对盐敏感品种效应更大。因此，施加外源GB或Pro可有效缓解盐胁迫对大麦种子萌发和幼苗生长的抑制作用。

Effect of Exogenous Betaine and Proline on Seed Germination and Seedling Growth of Barley under Salt Stress

In order to explore the effect of exogenous Betaine(GB) and Proline(Pro) on different barley varieties under salt stress,a salt tolerant barley variety Zhongchuandamai and a salt sensitive variety ZY218 were selected as materials,and 200 mmol·L^-1 NaCl was used as stress conditions at germination and seedling stages. The exogenous GB with the concentration of 0,0.5,1.0,5.0 and 10.0 mmol·L^-1 and the exogenous Pro with the concentration of 0,5.0,15.0,30.0,and 45.0 mmol·L^-1 were applied. The results showed that compared with G₀ and P₀,exogenous GB and Pro effectively alleviated the inhibition of salt stress on barley seed germination and aboveground growth. The activities of peroxidase(POD),superoxide dismutase(SOD),and catalase(CAT),and chlorophyll content in leaves were increased. Exogenous Pro significantly increased the total root length,total root volume,and total root surface area of seedling,effectively alleviated the inhibition of salt stress on barley seedling roots,and had a greater effect on salt sensitive variety. Therefore,exogenous GB or Pro can effectively alleviate the inhibition of salt stress on barley seed germination and seedling growth.