摘要
利用叶绿素荧光这一光合作用的敏感指针,以河南农业大学试验基地栽种的冬小麦"西农979"灌浆期的旗叶为材料,采用Mini-PAM叶绿素荧光仪测定其光合作用的叶绿素荧光参数的日变化和对不同温度胁迫的响应,以及光响应曲线,求出光饱和点I0和半饱和光强Ik,研究其光合器官的光合作用特征。结果表明:1)在灌浆期冬小麦的光饱和点为2236.5μmol/(m2·s),半饱和光强Ik为647.7μmol/(m2·s),表明灌浆期的冬小麦旗叶对强光的耐受力较强。2)在日变化的测量中出现高温胁迫现象,Fv/Fm、q P、q L和Y(NO)指示光合作用对高温胁迫的响应波动较大;Y(II)在10:00达到全天最大值,随温度的升高不断下降,r ETR、q N、NPQ、Y(NPQ)均与Y(II)对高温胁迫的响应相互验证,对环境温度变化较为敏感,是评价冬小麦光合作用的重要指标。3)对不同温度胁迫的响应,q N、NPQ、Y(NPQ)和Y(NO)随温度升高存在转折点,且均为36℃,该温度下冬小麦旗叶光合器官开始失活或被破坏,在温度达到41℃以上时这种破坏趋于稳定,且十分严重。
In order to understand the characteristics of photosynthesis of winter wheat photosynthetic organs in grain filling stage,this research utilizes the chlorophyll fluorescence which is a sensitive pointer of photosynthesis. Winter wheat（Xinong979）was planted in the experimental base of Henan Agricultural University to study the diurnal variation characteristics of photosynthesis and the effect of high temperature stress of flag leaf in filling stage using Mini-PAM chlorophyll fluorescence system. The index ofthe light-response curvewas measured to explore the light saturation pointand the half-saturated light intensity. The results showed as follows. 1 ） Light saturation point in grain filling stage of winter wheat was 2236.5 μmol/ （ m^2 · s）, and the half-saturated light intensity is 647.7 μmol/（ m^2 · s） . It was showed that the flag leaf of winter wheat have strong tolerance of bright light in grain filling stage. 2） The high temperature stress phenomenon appeared in the process of measurement. The response of Fv/Fm,qP,qL and Y（NO） which indicated photosynthesis to high temperature stress fluctuation was relativelybig. Y（ II ） reached the maximum of all day at 10am, then decreased continuously with increasing temperature. The result of rETR, qN, NPQ, Y（NPQ） and the response of Y（ II ） to high temperature stresswereall mutual authentication. They were sensitive to environmental changes and can be used as sensitive index indicating the strength of the plant photosynthesis. 3） The turning points of qN,NPQ, Y（NPQ） and Y（NO） became stable at 36 ℃ in their changing course with treatment temperature increasing. It indicated that 36 ℃ was the index temperature at which photosynthetic organs of winter wheat became inactivation, or to be destroyed. The damage was stablewhen when the temperature was above 41 ℃ ,and it would be very serious.
出处
《气象与环境科学》
2017年第1期64-72,共9页
Meteorological and Environmental Sciences
基金
国家自然科学基金项目(31370621
31071321)资助
关键词
冬小麦
灌浆期
旗叶
光合日变化
光响应曲线
高温胁迫
winter wheat
grain filling stage
flag leaf
photosynthetic diurnal variation
light-response curve
high temperature stress
