三种豆科牧草种子在萌发阶段对盐渍环境的生理适应及主要离子调控

Physiological adaptation and ion regulation of three leguminous species seeds at their germination stage to saline environment.

试验对3种豆科牧草紫花苜蓿、草木樨、沙打旺的种子,在萌发阶段对盐渍环境的适应性和离子调控机制进行了研究,测定了盐渍环境中种子的萌发率和恢复萌发率;同时,对400mmol·L-1NaCl处理后,种子恢复萌发、胚的主要离子含量变化、水分吸收等情况进行了测定。结果表明:50mmol·L-1NaCl处理中,紫花苜蓿种子的最终萌发率受到明显的抑制而降低;300mmol·L-1NaCl溶液处理中,草木樨的最终萌发率明显高于紫花苜蓿和沙打旺;沙打旺种子的初始萌发过程被300mmol·L-1NaCl抑制而推迟,推迟的时间长于紫花苜蓿和草木樨达5d。400mmol·L-1NaCl处理种子1、2和4d后,3种植物种子的吸水速率受到明显抑制;紫花苜蓿种子的恢复萌发率明显低于草木樨和沙打旺;紫花苜蓿种子胚积累的Na+明显高于草木樨和沙打旺,而且有较多的K+和Ca2+养分离子流失。盐渍环境下,3种牧草种子萌发受到的影响是由于渗透胁迫和离子毒害引起的,但3种植物种子的生理适应机制却存在明显的差异。

To understand the lilotus officinalis, and Astrag, adaptability and ion regulation mechanisms of ,alus adsurgens seeds at their germination stage to saline environment, the seeds were treated with different concentrations of NaCl, and their germination rate and recovery germination rate were determined. In the meantime, the changes of main ions contents in seed embryos and the water uptake by the embryos at 400 mmol·L^-1 of NaCI were investigated. At 50mmol·L^-1 of NaCI, the final germination rate of M. sativa seeds was obviously inhibited and decreased; while at 300mmol·L^-1 of NaCl, the final seed germination rate of M. officinalis was obviously higher than that of M. sativa and A. adsurgens, and the initiation of seed germination process of A. adsurgens was 5 days later than that of M. sativa and M. officinalis. M. sativa seeds rarely germinated at 400mmol·L^-1 of NaCl. After treated with 400 mmol·L^-1 of NaC1 for 1, 2, and 4 days, the water uptake by the seeds of test three species was obviously inhibited. The recovery seed germination rate of M. sativa was lower than that of the other two species, and the seed embryos of M. sativa accumulated more Na^＋ but leaked out more K^＋ and Ca^2＋. In saline environment, the impact on the seed germination of the three species was due to osmotic stress and ion toxicity, but the physiological adaptation mechanisms differed with different leguminous species seeds.