低场核磁共振技术在木薯种茎低温贮藏中的运用

Application of Low Field Nuclear Magnetic Resonance Imaging in Detecting Water Content of the Cassava Stem Stored under Low Temperature

以华南5号（SC5）和华南9号（SC9）木薯的种茎为材料,设药剂Ⅰ（预糊化氧化木薯淀粉）、药剂Ⅱ（预糊化氧化木薯粉）和对照（CK）3个处理,利用低场核磁共振成像（LF-NMRI）技术,研究木薯种茎在低温（0℃）贮藏过程中水分的相态和移动性,探讨其对发芽率的影响。结果表明：木薯种茎水分以自由水为主,占55%~75%,主要分布在种茎韧皮部;与对照相比,药剂处理可以提高种茎成活率,且药剂Ⅰ效果较好;同时发现,SC9种茎低温贮藏后成活率高于SC5,可见SC9比SC5较耐低温。

Stems of two cassava varieties SC5 and SC9 were treated with pregelatinized oxidized cassava starch（ Treatment 1）,pregelatinized oxidized cassava meal（ Treatment 2） and blank as control,and stored under low temperature（ 0 ℃）. The Low Field Nuclear Magnetic Resonance Imaging（ LF-NMRI） method was used to determine the water states and water mobility of the treated cassava stems in view of exploring the effects of water states and water mobility on the survival rate of the treated cassava stems stored under low temperature. Observations showed that free water was the main state of water in the treated cassava stems,accounting for 55%-75%,and mainly distributed in the phloem of the cassava stems. The two treatments improved the survival rate of the cassava stems stored under low temperature as compared to the control,and Treatment 1 gave a higher survival rate of the cassava stems than Treatment 2. At the same time,the SC9 had a higher survival rate than the SC5 after low temperature storage. It could be concluded that the SC9 was higher in tolerance to low temperature than the SC5.