高温胁迫对水稻拔节期净光合速率·SPAD·叶绿素荧光动力学的影响

[目的]研究高温胁迫对水稻（Oryza satva L.）拔节期净光合速率、相对叶绿素含量（SPAD）和叶绿素荧光动力学参数的影响。[方法]供试水稻品种为江苏省镇江市常用品种镇稻6号。温度具体设定（一天按24 h计）如下：10：00为36℃,11：00为38℃,12：00为39℃1,3：00为40℃1,4：00为38℃,15：00为35℃。[结果]与对照组相比,高温胁迫下水稻的净光合速率、相对叶绿素含量和叶绿素荧光主要参数（Fm和Fv/Fm）均明显降低,并且随着胁迫温度的升高及胁迫时间的延长,下降幅度也逐步增大。[结论]高温显著降低了PSⅡ的Fv/Fm和Fm,说明高温抑制了光合碳代谢的电子供应,这与水稻叶片的净光合速率以及相对叶绿素含量指标变化情况相一致。

Effects of High Temperature Stress on the Chlorophyll Fluorescence Kinetics, SPAD and Net Photosynthesis Rate of Rice(Oryza satva L.)in Jointing Stage

[Objective] The aim was to study the effects of high temperature stress to net photosynthetic rate,SPAD and PSⅡ parameters of rice in jointing stage.[Result] The rice variety was No.6 commonly used at Changzhou,Jiangsu.The temperature was designed in one day as follows: 36 ℃ at 10:00,38 ℃ at 11:00,39 ℃ at 12:00,40 ℃ at 13:00,38 ℃ at 14:00,35 ℃ at 15:00.[Result] The results showed that net photosynthetic rate,SPAD and PSⅡ parameters(Fm and Fv/Fm) of rice in high temperature stress decreased obviously comparing with the control group,and the decreased degree was gradually large along with bulid-up of the stress temperature and prolongation of stress time.[Conclusion] The high temperature reduces Fm and Fv/Fm of PSⅡ remarkably,which shows that high temperature restrained electron supply of photosynthetic carbon metabolism,this is in accordance with net photosynthetic rate and SPAD of rice leaf.