短期NaCl与Na2CO3胁迫对紫花苜蓿种子萌发可恢复性的影响

探讨短期钠盐胁迫对紫花苜蓿种子萌发特性的影响。试验共设盐分类型、盐分浓度、温度及胁迫时间等4个因子，测定发芽率（势）等指标。结果表明：短期钠盐胁迫解除后，30℃发芽率最低，但温度无持续效应，前期温度仅影响前3天发芽，而不影响后期发芽；Na2CO3具有持久的抑制效应，各个测定指标均低于NaCl；随盐分浓度提高，发芽率逐渐降低，尽管250 mM显著抑制前3天发芽，但第5天该处理有显著恢复性萌发，表明盐分浓度为暂时性抑制效应；胁迫时间与盐分浓度效应类似，随胁迫时间延长，发芽率逐渐下降，30 h抑制前3天萌发，但胁迫解除后有较高的恢复萌发。

Effects of Short-term NaCl and Na2CO3 Stress on Recovery of Seed Germination of Medicago sativa L.

The present study explored the effect of short-term Na＋ salt stress on characteristic of seed germination of M.sativa.The four environmental factors used in the experimental setup included salt type,salt concentration,temperature and stress duration.Seed germination rate（potential） was assessed.The result showed that the lowest final germination rate was obtained at 30℃ when salinity stress was removed.No persistent effect of temperature treatment was found.Early temperature stress affected the germination rate only in the first 3 days and no in the later days.Na 2 CO 3 had a long-term inhibitory impact on germination and were significantly lower than NaCl in all measures.The final germination rate decreased gradually with the rise of salinity.There was substantial recovery of germination in the 5 th day from salinity stress although germination in the first 3 days was inhibited at 250 mmol/L concentration,indicating the short-term inhibitory effect of salt concentration.Similar effect could be observed for stress duration.Longer duration caused the lower final germination rate.Treatment for 30 h inhibited germination in the first 3 days and had higher recovery of germination in the 5 th day.Thus,variations in these environmental factors appeared to play variously significant roles in recovery of germination of M.sativa from short-term Na＋ salt stress.