Abstract An extreme high temperature during grain filling is an important environmental factor that reduce the yield and quality of rice. In this study, we compared the grain appearance, composition and starch structure of four rice varieties response to high temperature during grain filling. The results obviously revealed that two indica AUS varieties Halwa and Jamir showed more tolerance to high temperature during grain filling than either the japonica Nipponbare or another AUS rice DJ24. The data showed that Halwa and Jamir presented less chalkiness, less grain weight loss, less change of endosperm components as well as starch structure than Nipponbare and DJ24 under high temperature treatment. Hence, the results implied that Halwa and Jamir might be useful targets to further identify genetic mechanism response to high temperature, at least during grain filling and endosperm development. Moreover, these AUS varieties have potential application value in further breeding of rice with good quality and heat tolerance.

中文翻译：

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两个耐温籼稻灌浆期理化品质及淀粉结构特征

摘要 灌浆期极端高温是降低水稻产量和品质的重要环境因素。在本研究中，我们比较了四个水稻品种在灌浆过程中对高温的响应的籽粒外观、组成和淀粉结构。结果显然表明，与粳稻日本晴或其他 AUS 水稻 DJ24 相比，籼稻 AUS 品种 Halwa 和 Jamir 在灌浆过程中表现出更高的耐高温性。数据表明，在高温处理下，Halwa和Jamir比Nipponbare和DJ24表现出较少的垩白，较少的粒重损失，胚乳成分和淀粉结构的变化较小。因此，结果表明 Halwa 和 Jamir 可能是进一步确定对高温的遗传机制响应的有用目标，至少在籽粒灌浆和胚乳发育期间。此外，这些AUS品种在进一步育种优质耐热水稻方面具有潜在的应用价值。