氮肥对水稻籽粒淀粉合成关键酶活性及蒸煮食味品质的影响

选用稻米蒸煮食味品质有显著差异的4个粳稻品种,研究了氮肥对水稻灌浆成熟期籽粒淀粉合成关键酶活性及蒸煮食味品质的影响。结果表明,增施氮肥使籽粒蛋白质含量增加的比率明显大于直链淀粉;灌浆过程中不同品质类型的品种籽粒ADPG焦磷酸化酶和可溶性淀粉合成酶活性均为抽穗后18d出现峰值,但淀粉分支酶活性出现峰值的时间劣质品种比优质品种早;灌浆过程中籽粒ADPG焦磷酸化酶和可溶性淀粉合成酶活性不因氮肥的高低而发生变化,淀粉分支酶活性在灌浆前期受氮肥的影响很小,但灌浆后期随氮肥的增加酶活性呈下降趋势;灌浆部分时期籽粒ADPG焦磷酸化酶和可溶性淀粉合成酶活性品种和氮肥间表现互作,但淀粉分支酶活性在整个灌浆过程中均没表现互作。

Effects of nitrogen fertilizer on the enzyme activities involved in the starch synthesis and eating and cooking quality in rice grain

Four rice varieties different in eating and cooking quality were investigated to reveal the effect of nitrogen fertilizer on enzyme activities involved in starch synthesis during grain filling.The results showed that the increasing rate of protein content was obviously higher than that of amylase with increasing of nitrogen fertilizer.ADPglocose pyrophosphorylase(AGPP) and soluble starch synthase(SSS) reached the peak time on 18 day after filling time among 4 varieties.Starch branch enzyme(SBE) activities of high quality varieties were later to reach the peak time than that of low quality varieties.There were no remarkable effect of nitrogen fertilizer on AGPP and SSS activities during grain filling.The SBE activities were decreasing significantly in the late stage with increasing of nitrogen fertilizer.The interaction between varieties and nitrogen application was significant on AGPP and SSS activities and the interaction was no significant on SBE activities.