夜温升高对不同早籼稻品种灌浆期光合作用及保护酶活性的影响

The Effect of Nighttime Temperature Increase on the Photosynthesis and Activity of Protective Enzyme of Different Early Indica Rice Varieties at Filling Stage

为了探明夜温升高对早籼稻生育后期生长的影响,对两间玻璃室采用开、关窗两种方式以创造夜间不同温度条件,以不同类型早籼稻品种为材料,研究了夜温升高对不同类型早籼稻品种灌浆期光合作用及保护酶活性的影响。结果表明,夜温升高导致早籼稻灌浆期功能叶片的净光合速率(P n)、Rubisco酶及保护酶活性不同程度地下降,丙二醛(MDA)含量增加。不同类型早籼稻品种灌浆期光合作用及保护酶活性对夜温升高的响应存在差异:杂交品种P n夜温升高时下降幅度小于常规品种;灌浆期杂交品种Rubisco酶和保护酶活性较常规品种高,但其夜温升高时下降幅度大于常规品种;灌浆中后期常规品种夜温升高时MDA含量增加较杂交品种明显。结论是夜温升高缩短了不同早籼稻品种灌浆期光合速率高值持续期,加速了叶片保护酶活性下降,导致膜脂过氧化加剧,杂交品种较常规品种更能耐受夜温升高的影响。

In order to study the effect of nighttime temperature increase on growth of early indica rice, u- sing different early indica rice varieties to study the photosynthesis and protective enzyme activity during the filling stage, two glasshouses were used to establish different nighttime temperatures. The results showed that higher nighttime temperature decreased net photosynthetic rate （Pn）, Rubisco and protective enzyme activity to different extent, but increased MDA content at the filling stage. There were significant different responses to higher nighttime temperature in different varieties of early indica rice.The Pn of early hybrid rice dropped less than that of common early rice.The activities of Rubisco and protective enzymes in early hybrid rice were high- er than those of common early flee, but they decreased more than in common early rice affected by higher nighttime temperature.The MDA content was higher in common early rice during the middle-late filling stage.The conclusion was that higher nighttime temperature shortened the period of higher photosynthesis rate, and sped up the decrease of protective enzymes activity, leading the membrane lipid peroxidation.Early hybrid rice endured hihter nighttime temperature better than common early rice.