外源物质浸种对NaCl胁迫下盐地碱蓬发芽的影响

用不同浓度的CaCl2（5.0、10.0、20.0、40.0 mmol·L-1）、水杨酸（0.05、0.5、1.0、2.0 mmol·L-1）和甜菜碱（5.0、10.0、20.0、40.0 mmol·L-1）3种外源物质对盐地碱蓬（Suaeda salsa）种子进行浸种处理，通过分析400 mmol·L-1NaCl胁迫下盐地碱蓬种子的发芽势、发芽率、平均发芽天数、发芽指数、幼芽长、幼根长、幼苗鲜质量等指标，探究外源物质对NaCl胁迫下盐地碱蓬种子发芽与幼苗生长的影响。结果表明，400 mmol·L-1 NaCl胁迫显著降低了盐地碱蓬种子的发芽率和发芽速度，严重抑制了盐地碱蓬幼苗生长。适宜浓度范围的外源物质浸种，均可显著提高盐地碱蓬种子的发芽率和发芽速度，促进盐地碱蓬幼苗生长，明显缓解植物受到的盐胁迫伤害。NaCl胁迫下，CaCl2、水杨酸和甜菜碱的最佳浸种浓度分别是20.0、1.0和20.0 mmol·L-1，3种外源物质对比分析结果显示，选用甜菜碱对盐地碱蓬种子进行浸种处理的应用效果最好。

Effects of exogenous substances priming on Suaeda salsa seed germination under NaCl stress

This study investigated the effects of exogenous substances on seed germination and seedling growth of Suaeda salsa under NaCl stress, especially on seed germination enevgyl, germination rate, germination index, average germination speed, shoot and root length, and fresh weight of seedlings under the condition of phytotron. The exogenous substances consist of CaCl2 (5.0, 10.0, 20.0, 40.0 mmol·L-1), salicylic acid (0.05, 0.5, 1.0, 2.0 mmol·L-1) and betaine (5.0, 10.0, 20.0, 40.0 mmol·L-1). The results showed that seed germination rate and speed significantly reduced and accompanied with severe inhibition of seedling growth under NaCl stress. Soaking with appropriate concentrations of exogenous substances could increase seed germination rate and speed significantly, promote seedling growth, it could alleviate salt injury to S.salsa. Under condition of 400 mmol·L-1 NaCl stress, the optimal concentrations of CaCl2, salicylic acid and betaine were 20.0, 1.0 and 20.0 mmol·L-1, respectively. Comparative analysis showed that integrated effects of betaine (20.0 mmol·L-1) were the best.