中文摘要：

利用Mini-PAM叶绿素荧光仪,测定了冬小麦旗叶在不同温度胁迫下不同时间点光合作用PS II的Fv/Fm、Y（II）、q P、q L、ETR、q N、NPQ、Y（NPQ）和Y（NO）等荧光参数,以研究冬小麦旗叶高温胁迫的温度指标。结果表明,1）Y（II）、q P、q L、ETR和Fv/Fm在不同处理时间点时均随温度升高而下降,并呈现Logistic曲线变化趋势;2）Y（II）、q P、q L、ETR和Fv/Fm降低50%时对应的温度T50随处理时间的延长而降低;3）Y（II）,q P,q L和ETR的T50均稳定在32℃,冬小麦旗叶在该温度开始热胁迫伤害;q N、NPQ、Y（NPQ）和Y（NO）的转折点均为36℃,该温度下冬小麦PS II开始失活或被破坏;由Fv/Fm和q N、NPQ、Y（NPQ）和Y（NO）看出,40℃时导致冬小麦旗叶热死亡。

英文摘要：

The index （ Fv/Fm, Y （ H） , qP, qL, ETR, qN, NPQ, Y（ NPQ） , Y（ NO） ） of chlorophyll fluorescence for photosynthesis PSII center of the flag leaf of winter wheat was measured to explore the effect of high temperature stress on injury of winter wheat. The results showed： 1 ） Y （H）, qP,qL, ETR, Fv/Fm of different treatment times decreased with temperatures increasing, and submitted to Logistic curves law. 2） When Y （H） , qP, qL, ETR, Fv/Fm decreased to 50% of the original value, the corresponding temperature. Ts0 decreased with the increase of treatment time. 3） All of T50s of Y （H） , qP, qL, and ETR became stable at 32℃ in their decreasing course with treatment time increasing, indicating that 32℃ was the starting temperature of heat stress. In the same course of temperature increasing, qN, NPQ, Y（NPQ） , and Y（NO） turned with the temperature increasing, and there were clear turning points. The turning points became stable at 36℃ in their changing course with treatment time increasing. It indicated that 36℃ was the index temperature at which PSII of winter wheat became inactivation, or to be destroied. 40℃ was the winter wheat death temperature, which could be drawn from Fv/Fm and qN, NPQ, Y（NPQ）, Y（ NO ）.