基肥氮后移对早造杂交稻产量、品质及米粉糊化特征的影响

Grain Yield,Quality and the Gelatinization of Rice Flour in Early Hybrid Rice as Affected by Basic Nitrogen Postponed for Heading Stage

以杂交组合华优8305、华优香占和培杂35为材料,用常规籼稻华粳籼74为对照,在施氮总量不变的基础上,减少基肥中氮的施用,研究了部分氮肥后移至抽穗期追施对早造杂交稻产量与主要品质性状及米粉糊化特征的影响.结果表明,将基肥氮后移至抽穗期施用对早造杂交稻产量及品质有一定影响,具体表现为整精米率和籽粒粗蛋白含量显著增加,米粉流胶长度变长,胶稠度变软,稻米垩白的变化因品种而异.杂交稻米粉RVA谱黏滞曲线和米粉在尿素中的糊化特征也明显受到基肥氮后移的影响,最高粘度和热浆粘度明显提高,最终粘度、崩解值和回复值显著降低,基肥氮后移处理的米粉在相同浓度尿素（4~7 mol/L）溶液中的膨胀体积要明显大于一次基施处理.可见,在减少基肥氮施用、部分氮肥后移至抽穗期施用的情况下,能提高稻米产量、改善部分品质性状.

Three hybrid combinations of Huayou8305,Huayouxiangzhan and Peiza35 were used as materials to study the effects of postponing nitrogen application time on yield,grain quality and rice flour RVA profile by field experiment.The results showed that yield and quality of hybrid rice was influenced by nitrogen fertilizer applied at heading stage when the amount of nitrogen as basal fertilizer was reduced.Increase in the head milled rice and crude protein content were found,gel consistency became soft,and chalk was varied according varieties when basic nitrogen was postponed to heading stage.The pronounced effects were observed on the RVA profile and the gelatinization of rice flour dissolved in urea with different concentration.When postponing nitrogen application time,the peak viscosity and through viscosity were enhanced,but final viscosity,breakdown and setback were reduced significantly.The swelling volume of rice flour with nitrogen application postponed was more than that with total nitrogen applied before transplanting when dissolved in urea with concentration from 4 to 7 mol/L.It was concluded that N application postponed to heading stage availed the ascending of rice yield and the improving of rice quality in part.