选用扬稻6号（籼稻）和武育粳3号（粳稻）两个品种，利用人工气候室进行灌浆结实期阶段控温试验，探讨结实期高温对稻米品质指标和淀粉RVA的影响，以及温度影响的时段效应。结果表明，结实期温度对稻米品质影响明显，且不同品种、不同品质指标对温度的反应存在差异。结实期高温，使两品种长宽比变小，垩白粒率、垩白度变大，糙米率、精米率和整精米率显著降低，蛋白质含量升高，淀粉RVA谱特征值糊化开始温度、冷胶黏度、回复值和消减值升高，最高黏度、热浆黏度和崩解值下降；结实期温度对AC的影响因品种而异，高温使扬稻6号AC升高，武育粳3号AC降低。全结实期高温对稻米品质的影响最大，结实前期高温次之，结实后期高温的影响较小。从抽穗到开花后20 d是温度影响稻米品质的关键时期，对稻米品质的形成具有决定性作用，而结实后期（开花20 d后）环境温度对稻米品质的影响较弱。
The temperature of rice grain-filling stage is the primary ecologic factor for rice qualities. Yangdao6 (indica rice) and Wuyujing3 (japonica rice) were used to study the effects of higher temperatures in different filling stage on rice qualities and characteristic values of Rapidvisco-analyzer with climatic cabinets. The temperature treatments were as follows: higher temperature (30℃) in whole grain-filling stage (A); higher temperature in early grain-filling stage (GFS) and optimum temperature (23℃) in later GFS stage (B); optimum temperature in early GFS and higher temperature in later GFS(C); optimum temperature in whole GFS (D,CK) (Table 1). The results showed that, different cultivars had different responses to various temperature treatments, and so did the various indexes of rice qualities. With high temperature in GFS, rice grain chalkness rate and grain chalkness were increased, while the brow rice rate, the milled rice rate and the head rice rate decreased significantly (Table 2); the effects of GFS temperature on rice AC value were various with cultivars, under high temperature treatments, Yangdao 6’s AC value were increased, while Wuyujing3’s AC value decreased (Fig.1). Under high temperature treatments, both cultivars performed higher protein content (Fig.2), higher Gelatinization temperature, Final viscosity, Consistency and Setback, lower Peak viscosity, Hot viscosity, and Breakdown (Table 3). Compared with D treatment, the rice qualities were affected by a treatment mostly, moderately by B treatment, while least by C treatment. The rice quality indexes under A and B treatments were various greatly with those under C and D treatment; while those under A treatment were various slightly with those under B treatment, and so did those under C treatment with D treatment. It can be concluded that: the period from heading to the 20 days later is the vital stage for whole rice quality in response to higher temperature, which affects rice qualities decisively; while the effect of the temperature in the later stage (beyond 20 days from heading) is slight. And the effect of higher temperature on some parameters of quality differs with cultivar, even though higher temperature degrades whole rice quality in general.
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