高温对杂交水稻籽粒灌浆和剑叶某些生理特性的影响

以杂交籼稻特优559为材料,探讨了高温胁迫对水稻灌浆期剑叶中有关生理特性和籽粒灌浆速率的影响.结果表明:高温胁迫加速了剑叶叶绿素的丧失,使SOD活性明显降低,质膜透性和MDA含量明显增加,脯氨酸、AsA、GSH、可溶性蛋白质以及可溶性糖含量明显降低,籽粒灌浆速率和籽粒重下降.高温使灌浆期水稻叶片衰老加速、光合能力下降是其导致灌浆速率、结实率、粒重和籽粒产量降低的主要生理原因.

Effects of High Temperature on Grain Filling and Some Physiological Characteristic in Flag Leaves of Hybrid Rice

The effects of high temperature on grain filling rate and some physiological indexes in flag leaves in hybrid rice Teyou 559 were studied. The results showed that chlorophyll content and super- oxide dismutase (SOD) activity in flag leaves were lower significantly by high temperature stress (Figs. 2A and 3A). The electrolyte leakage and malondialdehyde (MDA) content were higher sig- nificantly under high temperature stress (Figs.2B and 3B). The proline (Pro), ascorbic acid (AsA), glu- tathione (GSH), soluble protein and soluble sugar contents were lower significantly by high tempera- ture stress than those of the control (Figs.4, 5 and 6). Both the rate of grain filling and grain dry matter accumulation become lower significantly under hightemperature stress (Figs.7 and 8). Therefore, it was suggested that high temperature accelerated the se- nescence of rice leaf and decreased the photosyn- thesis rate during grain filling period, and then which was the main reason in physiology which resulted the decrease of grain filling rate, seed setting rate, grain weight and yield.