灌浆期表观直链淀粉含量相似品种稻米胶稠度和RVA谱的动态差异

 【目的】从品质形成的动态角度探讨相似AAC（apparent amylose content, 表观直链淀粉含量）水稻品种其米质动态形成的差异。【方法】选用成熟种子表观直链淀粉含量相似而米质不同的两个水稻品种武育粳3号和30优917为材料，研究其灌浆过程中直链淀粉含量、胶稠度及RVA谱动态变化差异。【结果】两个品种在籽粒灌浆过程中直链淀粉含量、胶稠度和RVA谱的动态变化存在显著差异。在花后5—15 d2个品种的直链淀粉含量存在显著差异，到灌浆后期则表现相近。胶稠度和RVA谱在籽粒灌浆的全过程中均有明显差异。与30优917相比，武育粳3号的胶稠度在花后5—10 d较软，到籽粒灌浆的中后期（花后20—40 d）却明显比30优917硬；用RVA测得的武育粳3号粘性较高，表现为较高的崩解值、较小的正消减值和较低的成糊温度。【结论】相似AAC水稻米质间的差异表现在灌浆期米质性状的动态形成存在显著差异，口感较好的武育粳3号其米粒形成过程中有较高的最高黏度、崩解值和较小的正消减值。

Dynamic Differences of the RVA Profile and Gel Consistency in Two Rice Varieties with Similar Apparent Amylose Content During Grain Filling

【Objective】 This study was performed to investigate the reason of the difference in the two rice varieties with similar apparent amylose content (AAC) by analyzing the dynamic formation of rice quality. 【Method】 Two rice cultivars Wuyujing3 and 30you917 with similar apparent amylose content were used as materials. The dynamic changes of gel consistency and RVA profile of the developing grains during the quality formation were studied. 【Result】 The differences were obviously found in the dynamic changes of amylose content, gel consistency and RVA profile of the developing grains. The difference in dynamic change of amylose content in two varieties from 5d to 15d after anthesis was significant, while the contents of amylose were nearly equal at late grain-filling stage. Gel consistency and RVA profile between the two varieties varied in the grain-filling period. The gel consistence of Wuyujing3 was softer than that of 30you917 at 5-10 d after anthesis, while harder than that of 30you917 at 20-40 d after anthesis. During the determination of RVA profile, Wuyujing3 represented higher stickiness such as big breakdown, small positive setback and low pasting temperature compared to 30you917. 【Conclusion】 These results suggested that the differences in the dynamic formation of the main quality indices during grain filling were the representation of the diversities of rices with similar apparent amylose content. It was Wuyujing3 that provided with higher peak viscosity, breakdown and lower positive setback during the formation of rice kernel and had high cooking and eating qualities.