NaCl胁迫对海滨木槿种子萌发及Na~+、K~+含量的影响

目的]探索不同浓度NaCl处理对海滨木槿种子萌发及种皮和种胚中Na+、K+含量的影响。方法]用NaCl浓度分别为0、50、100、150、200mmol/LNaCl的1/4Hoagland营养液培养材料,培养5、10d后以FP-640火焰分光光度计测定种皮和胚中的Na+、K+含量;培养15d后,将含有NaCl的营养液未萌发的种子分别转入1/4Hoagland培养液继续培养,测定解除盐胁迫后种子萌发的恢复率。结果]随着培养液中NaCl浓度的升高,海滨木槿种子的萌发率逐渐降低,在NaCl浓度为200mmol/L时种子的萌发率最低。种皮和胚中Na+含量随着培养液中NaCl浓度的升高和处理天数的延长而增大;在相同的盐浓度下,胚中Na+含量明显低于种皮。随着培养液中NaCl浓度的升高,种皮中K+含量逐渐升高,胚中K+含量逐渐降低,但胚中K+含量明显高于种皮。种皮和胚中Na+/K+随着NaCl浓度的升高而增大,胚中Na+/K+明显低于种皮。结论]海滨木槿的种皮是阻挡Na+进入种子的一道屏障;NaCl处理下胚保持较高含量的K+和较低的Na+/K+可能是海滨木槿种子耐盐的主要原因之一。

Effects of NaCI Stress on the Germination and the Content of Na and K of Hibiscus hamabo Sieb.et Zucc.Seeds

Objective]The research aimed to discuss the effects of salt treatment with different concentrations NaCl on the seed germination and the content of Na and K in seed coat and embryo of Hibiscus hamabo Sieb.et Zucc. Method]The materials were cultivated by 1/4 Hoagland nutrition solution with 0, 50, 100, 150, 200 mmol/L NaCl. the content of Na and K in seed coat and embryo was determined by frame spectrophotometer-640 when the seeds were treated for 5 days and todays. After 15 days, The no germination seeds in 1/4 Hoagland ntt nutrition solution with Na were cultivated by 1/4 Hoagland nutrition solution without NaCl to study the recovery rate of germination.Result]The results showed that the seed germination rate decreased gradually as the NaCl concentration increased and it was lowest when the seeds were treated with 200 mmol/L NaCl. The Na content of the seed coat and embryo increased gradually as the NaCl concentration increased and days progressed, the Na content of the embryo was significantly lower than that of seed coat under the same NaCl concentration. As the NaCl concentration increased, the K content of the seed coat increased gradually while it decreased gradually in the embryo, but the latter was significantly higher than the former. The Na /K of the seed coat and embryo increased gradually as the NaCl concentration increased, and the Na /K of the embryo was significantly lower than that of the seed coat. Conclusion]The seed coat of Hibiscus hamabo Sieb.et Zucc. could prevent Na into the seed and the higher K and the lower Na /K in the embryo could be one of key reasons of high-salinity resistance.