土壤可溶性盐含量对黄瓜种子萌发及其幼苗生长发育的影响

采用室内盆栽土培试验，研究了土壤中不同可溶性盐含量对黄瓜种子萌发及其幼苗生长发育的影响。结果表明，盆栽条件下，当土壤可溶性盐含量低于3 g·kg-1 时，黄瓜种子的发芽率、发芽指数和活力指数不受盐胁迫的影响；当土壤可溶性盐含量高于3 g·kg-1 时，黄瓜种子的发芽率、发芽指数和活力指数随土壤可溶性盐含量升高而逐渐降低，当土壤可溶性盐含量高于10 g·kg-1时，黄瓜种子几乎不发芽。对幼苗而言，当土壤可溶性盐含量低于3 g·kg-1 时，黄瓜幼苗的鲜重、株高、茎粗和根长等指标不受盐胁迫的影响，幼苗中丙二醛、可溶性糖和脯氨酸等表征逆境胁迫的生理生化指标也没有显著变化；当土壤可溶性盐含量高于3 g·kg-1 时，随可溶性盐含量的升高，黄瓜幼苗的鲜重、株高、茎粗和根长等指标逐渐降低。同时，幼苗叶片中丙二醛、可溶性糖和脯氨酸等生理生化指标迅速升高。当土壤可溶性盐含量为3 ～10 g·kg-1 时，土壤中的可溶性盐含量或电导率与黄瓜种子发芽指数之间存在极显著的负相关，说明在次生盐渍化的农田中，通过测定土壤中可溶性盐含量或电导率值可以预测黄瓜种子萌发和幼苗的生长发育状况。

Effects of soil soluble salt content on seed germination and seedling growth of cucumber

Pot experiment with soil in greenhouse was employed to investigate the effect of soil soluble salt content on seed germination and seedling growth of cucumber. The results were as follows: the germination percentage， germination index and vigor index of cucumber seeds were not affected by soil soluble salt lower than 3 g·kg-1. Meanwhile， germination percentage， germination index and vigor index of cucumber seeds decreased， when soluble salt content was more than 3 g·kg-1. The seeds almost didnt germinate， when soluble salt content was more than 10 g·kg-1. For seedlings， fresh weight， height， stem diameter and root length were not affected， and the contents of MDA， soluble sugar and proline didnt change significantly， when soil soluble salt content was lower than 3 g·kg-1. When soil soluble salt content was more than 3 g·kg-1， fresh weight， height， stem diameter and root length decreased gradually， and the contents of MDA， soluble sugar and proline of seedlings increased rapidly. There was a significant negative relationship between the germination index of cucumber seeds and the content of soluble salt in soil or soil conductivity， which showed that the condition of germination or seedling growth of cucumber could be forecasted by determination of soil soluble salt content and soil conductivity.