Abstract: Solutions of various concentration of NaCl,Na₂CO₃,and a mixture of the two were used for saline stress to measure and analyse the seed germination percentage and speed,and the growth of radical and plumule of three saline grasses- Leymus chinensis,Hordeum brevisubulatum, and Puccinellia chinampoensis -by saturating the seeds and then allaying the saline stress.The result shows that the L.chinensis and H.brevisubulatum seeds’ germination percentage and speed,and the growth of radical and plumule,in comparison,reduced with the strengthening of the salt concentration of Na₂CO₃,and the NaCl and Na₂CO₃ mixture.However,the P.chinampoensis seed germination percentage,and the growth of radical and plumule mounted and developed under the stress of low salt concentration of 12.5 mmol/L NaCl and 37.5 mmol/L Na⁺,but its seed germination speed diminished with the intensifying of the salt concentration.The Na₂CO₃ solution restrained all the three saline grasses’ radical and plumule growth.The salt stress of all the three solutions declined the growth of readicals of L.chinensis and P.chinampoensis more markedly than the growth of their plumules.The salt tolerance of P.chinampoensis seed during germination surpassed that of L.chinensis and of H.brevisubulatum in the same period.After allaying the salt stress,the three saline grasses’seed germination rate increased basically with the increase of pre-treatment salt concentration.

Key words: Grassland science, Salt stress, Germination rate, Saline grass, Germination ecology

摘要： 采用不同浓度的NaCl、Na₂CO₃和二者混合盐的胁迫,对羊草、野大麦和朝鲜碱茅种子的发芽率、发芽速度、胚根和胚芽的影响以及盐胁迫解除后的发芽率、胚根和胚芽的生长进行测定与分析。结果表明,随着Na₂CO₃和混合盐溶液浓度的增加,羊草和野大麦种子的发芽率、发芽速度、胚根和胚芽的相对生长均呈下降趋势;而12.5mmol/LNaCl和37.5mmol/LNa⁺混合盐的低浓度胁迫对朝鲜碱茅种子的萌发、胚根和胚芽的生长有促进作用,但发芽速度则随着盐浓度的升高而降低;Na₂CO₃溶液对3种禾草胚根和胚芽的生长均有明显的抑制作用;3种盐分胁迫对羊草和朝鲜碱茅胚根生长的影响均大于胚芽生长;朝鲜碱茅种子萌发时的耐盐性强于野大麦和羊草;盐胁迫解除后,3种禾草的发芽率随原胁迫盐浓度的增加呈升高趋势。

关键词: 草原学, 盐胁迫, 发芽率, 盐生禾草, 萌发生态