利用低场核磁共振分析水稻种子浸泡过程中的水分变化  

Analysis of moisture changes during rice seed soaking process using low-field NMR

作　　者：宋平[1,2,3,4] 杨涛[1] 王成 潘大宇 任鹏 

机构地区：[1]沈阳农业大学信息与电气工程学院,沈阳110866 [2]国家农业智能装备工程技术研究中心,北京100097 [3]农业部农业信息技术重点实验室,北京100097 [4]农业智能装备技术北京市重点实验室,北京100097

出　　处：《农业工程学报》2015年第15期279-284,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家高技术研究发展计划(863计划):作物生产智能监控关键技术与系统研究(2012AA10A503);国家重大科学仪器设备开发专项"便携式植物微观动态离子流检测设备研发与应用"(2011YQ080052);公益性行业(农业)科研专项"作物育种材料农艺性状信息高通量获取与辅助筛分技术"(201203026)

摘　　要：为研究水稻种子在浸泡过程中的水分变化情况,应用核磁共振无损、非侵入的技术优势,根据弛豫时间呈现的多组份特征,通过弛豫谱分析水稻种子不同相态水分的变化和流动过程,确定弛豫谱峰值总面积与水稻种子吸水率的回归方程,研究了水稻品种(沈农9816号、沈农9903号)及浸种温度(18、24、32℃)对水稻种子吸水量的影响。试验结果表明:通过弛豫谱峰值总面积可以合理估测水稻种子的吸水率;水稻种子在6h浸种过程中,随着浸泡时间的增加结合水及总水含量变化趋势为不断上升,自由水则呈现不规则的反复变化态势;水稻种子吸水量在2个水稻品种间差异不明显,对浸种温度高度敏感。该试验提出了一种无损的水分检测方法,能够更加直接准确的揭示水稻种子在浸泡过程中的水分变化规律,为探求种子的最佳浸泡条件提供数据支持和理论依据。Low field nuclear magnetic resonance（LF-NMR） has the technique advantages of nondestructive and non-invasive, which can be used to study the variation, distribution and flow of different phase state moisture in rice seed through the detection of proton＇s density and distribution in samples. In this paper, Shennong No. 9816 and No. 9903 rice seeds were used in the study. The center frequency and pulse width were determined using the FID pulse sequence in the NMR spectroscopic analysis software. The low field NMR technique and dynamic detection of the CPMG pulse sequence signal were used to determine the spin relaxation time of samples（the transverse relaxation time T2）. The variation and flow of different phase state moisture during seed soaking were analyzed by the change of time signal and the peak position due to the inversion mapping of T2. The value of the relaxation time T2 reflected the value of the water degree of freedom in the sample. The change of the relaxation time T2 can reflect the mobility of the water molecules. The effects of rice varieties and soaking temperature on the moisture absorption ratio has been studied according to the regression equation between the T2 relaxation spectrum total area of peak A and rice seed moisture absorption ratio. The experimental results showed that the regression equation of the T2 relaxation spectrum peak area and the moisture absorption ratio of rice seed was correlated well and the equation reached a significant（P 0.05） level of detection. The moisture absorption ratio of rice seed was reasonably estimated through the T2 relaxation spectrum peak area. The moisture in the rice seeds was in two phases, combined moisture and free moisture during soaking process according to the multiple components characteristics of T2 and moisture characteristics of the seed. The critical value of combined moisture and free moisture was 10 ms. The short relaxation time T21（0.1-10 ms） was defined as combined moisture. This water was closely linked to protein, sug

关 键 词：水分 核磁共振 种子 横向弛豫时间 反演谱 水稻 浸种 

分 类 号：S351.51[农业科学—作物栽培与耕作技术]