灌浆期干旱胁迫对水稻生理性状和产量的影响

目的 研究灌浆期干旱对不同类型水稻叶片生理性状和产量的影响,为干旱气候条件下水稻栽培提供参考。方法 以节水抗旱稻旱优113和普通杂交稻扬两优6号(YLY6)为材料,设置传统淹水灌溉、灌浆期干旱胁迫两个处理,分别测定水稻的产量及产量构成、稻米品质(加工品质、外观品质和营养品质)、干物质生产及分配、叶片生理活性(叶片水势、气叶温差和光合速率)等。结果 与传统淹水灌溉相比,灌浆期干旱胁迫下水稻叶片水势、气叶温差均显著下降,最终导致叶片光合速率降低;但是在复水后2~15 d,叶片的各生理指标可以得到恢复,与对照没有显著差异;水稻产量没有明显变化,产量的稳定主要得益于前期充足的干物质积累使籽粒充分灌浆,结实率显著升高;稻米的碾磨品质没有显著影响,但扬两优6号的外观品质显著降低,却改善了旱优113的外观品质。同时,蛋白质含量升高在一定程度上改善了稻米营养品质。结论 水稻灌浆期适度干旱可以在稳定产量的基础上改善稻米品质。因此,适当在生育后期阶段减少水分的投入,不仅可节约农业用水,稳定籽粒产量,还有利于稻米品质的改善。

Effects of Drought Stress at Grain Filling Stage on Rice Physiological Characteristics and Yield

【Objective】It is very important to reveal the effects of drought stress at grain filling stage on physiological characteristics of flag leaves and yield of different genotypes of rice, and provide the reference for rice cultivation under soil drought conditions.【Method】The water-saving and drought resistant rice variety Hanyou 113 (HY113) and hybrid rice variety Yangliangyou 6 (YLY6) were cultured as materials under two water treatments (conventional flooding and drought stress at grain filling stage). The yield and its components, rice quality (processing quality, appearance quality and nutritional quality), dry matter production and distribution, leaf physiological activity (leaf water potential, air-leaf temperature gap and photosynthetic rate) were determined.【Result】Compared with conventional flooding, the leaf water potential and air-leaf temperature gap significantly decreased under drought stress during grain filling, which resulted in decreased photosynthetic rates of flag leaves. However, from the 2nd to the 15th day after rehydration, the physiological activities of the flag leaves could be restored to the normal level, and no significant difference was observed as compared to control group. There was no significant change in grain yield, which was mainly due to accumulation of dry matter in the early growing stage and significantly increased filled grain number. The rice milling quality was not changed significantly, but the appearance quality of YLY6 was just the opposite, the appearance quality of HY113 was improved. In addition, the nutrition quality was improved due to increased protein content.【Conclusion】Moderate drought at grain filling stage can improve rice quality and stabilize grain yield. Therefore, moderate reduction of water input at late growing stages can not only save agricultural water and stabilize yield, but also help improve rice quality.