盐碱复合胁迫对湖南稷子种子萌发的影响

Effects of combined saline and alkaline stresses on seed germination of jizi in Hunan province

摘要:

【目的】研究盐碱复合胁迫对湖南稷子种子萌发和幼苗生长的影响。【方法】模拟盐碱地自然状态下盐分组成特点，以 2 种中性盐（NaCl、Na₂SO₄）和 2 种碱性盐（NaHCO₃、Na₂CO₃）分别按 1∶1∶0∶0 （A）、1∶2∶1∶0（B）、1∶9∶9∶1（C）、1∶1∶1∶1（D）、9∶1∶1∶9（E）的比例混合，以湖南稷子为材料，去离子水为对照（CK），研究盐碱混合胁迫对其萌发指标及幼苗生长的影响。【结果】湖南稷子种子的萌发率随盐分浓度的升高而明显下降（P＜0. 05）；但是，当盐浓度为 150 mmol/L 时，湖南稷子种子在第 5d 的发芽率较对照（97. 3%）分别降低了 8. 5%，16. 4%，23. 6%，随着盐的浓度增加到 250 mmol/L，湖南稷子的萌发率明显降低（P＜0. 01）；湖南稷子的发芽势、发芽指数、活力指数、根长及苗长等指标变化趋势均与发芽率的相吻合。湖南稷子种子在中性和碱性复合胁迫下的萌发受到了较大的抑制，而在 250 mmol/ L 的中性盐复配下，湖南稷子的所有发芽指数都为 0。随着盐分的升高，叶片中 Na⁺ 、脯氨酸、MDA 的含量逐渐上升，K⁺的含量则明显降低。【结论】随着盐胁迫浓度增加，对湖南稷子种子萌发的抑制作用越明显。本研究结果可为盐碱地湖南稷子的种植提供理论基础。

Abstract:

【Objective】To study the effects of saline and alkaline compound stresses on seed germination and seedling of Jizi in Hunan.【Method】 The experiment simulated the characteristics of salt composition in the natural state of saline and alkaline land. Two neutral salts （NaCl，Na₂SO₄） and two alkaline salts （NaHCO₃，Na₂CO₃） were mixed in the ratios of 1∶1∶0∶0，1∶2∶1∶0，1∶9∶9∶1，1∶1∶1∶1，and 9∶1∶1∶9，which were labeled as A，B，C，D，and E treatments，respectively，with deionized water as control （CK）. This research investigated the effects of mixed saline and alkaline stresses on their germination indexes and seedling growth of Hunan Jizi .【Result】 The germination rate of Hunan jizi seeds decreased significantly （P＜0. 05） with the increase of salt concentration. On the 5th day，the germination rates of Hunan jizi seeds were 8. 5%，16. 4%，and 23. 6% lower than that of the control （97. 3%） when the salt concentration was 150 mmol/L，and salt concentrations increased up to 250 mmol/L. The significant decrease （P ＜0. 01） of Hunan jizi seeds' germination rate indicates that the mixed stresses of salinity and alkalinity had a strong inhibitory effect on the germination of Hunan Jizi. The changes of germination potential，germination index，vigor index，root length and seedling length of Hunan Jizi were all in line with the germination rate. The germination of Hunan Jixi seeds under neutral and alkaline compound stresses was greatly inhibited，while all germination indices of Hunan Jixi under neutral salt compound of 250 mmol/L were 0. With the increase of salinity，the contents of Na⁺ ，proline，and MDA in the leaves increased gradually，while the content of K⁺ decreased significantly.【Conclusion】 The increase in salt concentration inhibited the germination of Hunan Jizi. The results of this study provide a theoretical basis for the cultivation of Hunan Jizi in saline soil.