利用低场核磁共振及其成像技术分析水稻浸种过程水分传递  

Analysis on moisture transport in process of rice soaking using low field nuclear magnetic resonance and its imaging

作　　者：宋平[1,2,3,4] 徐静[1] 马贺男[5] 王成 杨涛[1] 李娜[1] 

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 [5]中国刑事警察学院网络犯罪侦查系,沈阳110854

出　　处：《农业工程学报》2016年第17期274-280,共7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：为研究水稻种子浸种过程中内部水分流动情况,可视化内部水分传递过程,利用低场核磁共振及其成像技术,监测沈农9816号、七山占及秀子糯3个品种水稻种子48 h浸种过程。每6 h时间间隔利用自旋回波(spin echo,SE)脉冲序列获取样品的质子密度加权像,利用硬脉冲自旋回波(carr-purcell-meiboomgill sequence,CPMG)序列获取样品的横向弛豫时间T2反演谱,从而分析浸种过程对水稻种子内部水分分布的影响。试验结果表明:核磁共振是一种有效的水分检测技术,可以实现浸种过程中种子内部水分的快速、准确、无损的检测。利用水稻种子的质子密度加权像,能够直观检测到种子内部水分分布情况,动态的监测到种子内部水分流动过程,分析发现水分最初是从胚进入种子内部,继而通过种皮的渗透,最后到达胚乳部分。根据T2反演谱信号幅值计算得到的水稻种子吸水率,发现3个品种在相同浸种时间的各个监测点均反映出秀子糯吸水率最高,沈农9816号吸水率最低,试验结果验证了支链淀粉的吸水性优于直链淀粉。研究结果可以为水稻种子浸种过程中水分传递的理论模型构建提供数据支持。In order to study the internal water flow process of rice seed in presoaking and visualize the internal water transport process, an experiment of monitoring three varieties of rice seeds, namely SYAU No. 9816, Qi-shan-zhan, and Xiu-zi-nuo, during a 48 h presoaking process with TD-NMR and MRI technology has been conducted. To learn the effect of the presoaking process on rice seed water distribution and water absorption, during the experiment period, the PDWIs of all samples have been obtained with SE pulse sequence, and the T2 spectral deconvolution images have been obtained with the CPMG pulse sequence every 6 hours. During the observation period, after presoaking for 0 hour, 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, 36 hours, 48 hours, spin-echo（spin echo, SE） pulse sequence had been used to obtain proton density-weighted images of all the samples. CPMG（carr-purcell-meiboomgill sequence, CPMG） sequence had been used to obtain the transverse relaxation time T2 inversion spectrum of all the samples, so as to analyze the impact of seed soaking of the internal water distribution of rice seeds. NIUMAG MRI image processing software had been used on the 256 pixel × 256 pixel grayscale images acquired by the magnetic resonance imaging software for unified grayscale, pseudo color images, filtering and other processing, to adapt the images into forms that were more suitable for observation. The average value of the 3 CPMG pulse sequence value generated by the analysis software after repeated application of NMR signal at different corresponding time and the peak value had been calculated and the average value had been imported into NMR inversion software to obtain T2 spectral deconvolution. The experiment results showed that： MRI is an effective water detection technology, with whose help the internal water of rice seeds during presoaking can be monitored efficiently, accurately, without any loss. The use of T2 relaxation spectrum and proton density-weighted images helped to obtain a sample of internal h

关 键 词：水分 核磁共振 种子 质子密度加权像 伪彩图 浸种 水分传递 T2反演谱 

分 类 号：S351.51[农业科学—作物栽培与耕作技术]