盐、碱胁迫下水稻种子萌发过程水分含量变化及对种子发芽影响的低场核磁检测研究

Research on the Moisture Content Variation and Influence to Rice Seed Germination under Salt and Alkali Stress by Low Field NMR

为研究盐、碱胁迫下水稻种子萌发过程水分含量变化及对种子发芽的影响,以及利用低场核磁检测技术测定种子含水量的可行性,利用光照培养箱进行培养皿种子发芽试验,分析了在蒸馏水(对照处理)、浓度为50、150mmol/L NaCl和NaHCO_(3)胁迫处理下,盐粳48和辽星1种子萌发72h过程中核磁信号幅值变化及各处理对发芽指标的影响,确定单位质量水稻种子样品核磁信号幅值与湿基含水率的回归函数关系。结果表明,与对照处理相比,萌发6、24、48、72h后,2个品种水稻种子核磁信号幅值平均分别增长了65%、95%、115%和135%以上。萌发相同时间后,相比对照处理,NaCl和NaHCO_(3)胁迫处理下核磁信号幅值平均降低了5%以上,发芽指数平均降低了4.5%以上,说明水稻种子萌发过程水分含量与种子发芽指数呈正相关。不同浓度NaCl和NaHCO_(3)胁迫下,单位质量水稻种子核磁信号幅值和湿基含水率之间均具有一致的线性关系,R^(2)均大于0.95。说明利用核磁共振技术测定盐、碱胁迫下水稻种子的水分含量是合理可靠的。

In order to study the change of moisture content and its effects on the rice seeds germination under salt and alkali stress,and the feasibility of using low field nuclear magnetic detection technology to determine seed moisture content,two varieties(Yanjing 48 and Liaoxing 1)of rice seeds were placed in culture dish with the solution of 50,150mmol/L NaCl,NaHCO_(3) and distilled water(control)respectively,nuclear magnetic resonance signal amplitude variation and effects of different solutions on germination characteristics were analyzed,and the regression equation was deduced between NMR signal amplitude per unit mass rice seed samples and the wet base moisture content.The results showed that the nuclear magnetic signal amplitudes of the two varieties of rice seeds increased by 65%,95%,115%and 135%respectively after seeds germination 6,22,48,and 72h compared with control treatment.After germination for the same time,the amplitude of NMR signal decreased by more than 5%under NaCl and NaHCO_(3) stress,the germination index decreased by more than 4.5%compared with the control treatment,indicating that there was a positive correlation between moisture content and seed germination index.There was a consistent linear correlation between NMR signal amplitude per unit mass and the wet base moisture content under different NaCl and NaHCO_(3) stress,R^(2) were all greater than 0.95.The results showed that it was reasonable and reliable to measure the water content of rice seeds under salt and alkali stress by nuclear magnetic resonance technology.