镁对稻米食味品质的影响

Effect of Mg Fertilizer on Rice Taste Quality

以丰优香占,汕优63,华粳3号,镇稻88为材料,采用水培和大田孕穗前喷肥方法,分析镁肥对水稻品质的影响。结果表明:镁对稻米糊化温度没有显著影响。在喷施镁肥试验中,稻米直链淀粉(AC)含量随着镁肥施用量的增加而升高,不同镁肥处理间差异不显著,4个品种表现基本一致。在水培试验中施镁对稻米直链淀粉含量影响不显著。淀粉粘滞性谱特征值中的最高粘度、热浆粘度和崩解值均随水培液中镁浓度的升高而升高,达到一定浓度后开始减小;冷胶粘度、回复值和消减值表现出相反的变化趋势。不同的品种,达到最大值时的处理浓度不同。大田喷施试验结果表明,与对照相比,喷施镁肥处理在多数情况下能显著提高RVA谱特征值中的最高粘度、热浆粘度和崩解值,降低冷胶粘度、回复值和消减值。各喷施镁肥处理显著提高了精米中的镁钾元素含量、镁钾含量比(Mg/K)和Mg/(N.AC.K)。Mg/K和Mg/(N.AC.K)与稻米淀粉粘滞性谱特征值存在一定的相关性,但是在不同品种间和不同指标间存在差异。

Eating qualities of two lndica rice cultivars, Fengyouxiangzhan and Shanyou 63, two Japonica rice cultivars, Huajing 3 and Zhendao 88, were investigated under two circumstances, hydroponic culture applied with Mg（Treatment A） and spraying Mg fertilizer before booting（Treatment B）. Mg had no distinct effect on gelationizaiton temperature in both treatments. In Treatment B, the amylose contents in the grains of all four rice cultivars went up with the increase of Mg fertilizer rates. While in treatment A,Mg changed the amylase contents little. Characteristic values of rapid viscosity of amylose （RVA） such as peak viscosity, hot viscosity and breakdown first climbed up to a certain point then declined as the Mg concentration in the culture solution was elevated. Other characteristic values such as final viscosity, setback and consistency exhibited the opposite responses to Mg concentration changes. Mg concentration varied for different rice cultivars when their characteristic values were at the maximum. Compared to CK（ spraying water） , Mg fertilizer spraying raised the peak viscosity, hot viscosity and breakdown, but decreased the final viscosity, setback and consistency. The contents of Mg and K, Mg/K and Mg/（ N · AC · K） were also increased in treatment B. There was a correlation between Mg/K,Mg/（ N · AC · K） and the characteristic values of RVA.