Abstract: Three accessories of Poa Pratensis were separately collected from HunYuan (HY accessory),YingXian (YX accessory) and QinShui (QS accessory) county of Shanxi Province and treated 26 d by the concentrations of 0,50,100,150,200,250 and 300 mmol·L^-1 NaCl,respectively. Leaf relative water content,relative permeability of plasma membrane,superoxide dismutase activities,malondialdehyde content,proline content,soluble sugar content,soluble protein content and photosynthetic parameters were determined after sampling,and salt tolerance was analyzed using subordinate function. The results were as follows:with increasing salt concentration,the leaf relative water content and soluble protein content showed a declining trend in all three accessories,while leaf plasma membrane permeability,malondialdehyde contents and proline contents showed a rising trend in all three accessories. Superoxide dismutase activities and soluble sugar contents increased at initial stage and then declined with the increase of salt concentration in YingXian and QinShui accessories,but continuously rose in HunYuan accessory. Net photosynthesis rate,stomatal conductance and transpiration rate declined with increasing salt concentration. Intercelluar CO₂ concentrations declined with increasing salt concentration in lower salt concentration(<150 mmol·L^-1),and increased within the range of higher concentration(200~300 mmol·L^-1). Comprehensive analysis using subordinate function,HunYuan accessory exhibited the strongest salt tolerance,then YingXian accessory and QinShui accessory.

Key words: Wild Kentucky bluegrass, Abiotic stress, Salt tolerance

摘要： 试验以山西3个不同居群野生草地早熟禾（HY居群、YX居群、QS居群）为材料，采用不同浓度的NaCl溶液（0、50 mmol·L^-1、100 mmol·L^-1、150 mmol·L^-1、200 mmol·L^-1、250 mmol·L^-1、300 mmol·L^-1）胁迫处理26 d后，测定叶片相对含水量（RWC）、质膜相对透性、超氧化物歧化酶（SOD）活性、丙二醛（MDA）、脯氨酸（Pro）、可溶性糖（SS）、可溶性蛋白（SP）含量以及光合参数，并采用隶属函数法综合分析3个野生优异居群的耐盐性。结果表明：随NaCl胁迫浓度的升高，HY居群、YX居群和QS居群的RWC和SP含量均呈下降趋势；质膜相对透性、MDA含量、Pro含量均呈升高趋势；SOD活性和SS含量在YX居群、QS居群中均呈先升高后降低趋势，而HY居群则呈持续升高趋势。3个居群的净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）均随胁迫浓度的升高呈下降趋势；胞间CO₂浓度（Ci）在0~150 mmol·L^-1NaCl胁迫下随盐浓度的升高而降低，但在200~300 mmol·L^-1NaCl胁迫下随盐浓度的升高而升高。3个居群草地早熟禾的耐盐性：HY居群 > YX居群 > QS居群。

关键词: 野生草地早熟禾, 非生物胁迫, 耐盐性