小麦旗叶光呼吸对光强和CO_2浓度的响应  

Response of Photorespiration of Wheat Flag Leaf to Light Intensities and CO_2 Concentrations

作　　者：康华靖[1,2,3,4] 王巍伟[1] 权伟[1] 杨翔[1] 欧阳竹 

机构地区：[1]温州科技职业学院,浙江温州325006 [2]中国科学研究院地理科学与资源研究所生态网络观测与模拟重点实验室,北京100101 [3]中国科学研究院禹城综合试验站,北京100101 [4]中国科学研究院研究生院,北京100101

出　　处：《麦类作物学报》2013年第6期1208-1215,共8页Journal of Triticeae Crops

基　　金：国家高技术研究发展计划(863计划)项目(2013AA102903);中国科学院地理科学与资源研究所"一三五"战略科技计划项目(2012ZD004);浙江省教育厅项目(y201326719)

摘　　要：为给C3作物光呼吸等光合参数以及光响应模型和CO2响应模型的研究提供参考,定量研究了小麦花期旗叶光呼吸速率对光强和CO2浓度的响应。结果表明,在21%和2%O2下小麦旗叶光饱和点分别为1 960.629和2 030.120μmol·m-2·s-1。在较弱光强(小于800μmol·m-2·s-1)下,小麦的总光呼吸速率(Rpt)与表观光呼吸(Rpa)均随着光强的升高而增大;当光强大于800μmol·m-2·s-1时,Rpt和Rpa趋于稳定;整体上,不同光强下Rpt与Rpa之间差异较小(P>0.05),这主要是由于在380μmol·mol-1 CO2下,光呼吸的CO2回收利用率较低。饱和光强下,Rpa随着CO2浓度的增加呈先上升后下降的趋势,Rpa最大值(Rpmax)所对应的外界CO2浓度为600μmol·mol-1,而Rpt则随着CO2浓度的升高而降低;在低浓度CO2(小于380μmol·mol-1)条件下,Rpt与Rpa之间差异显著(P<0.05)。Rpt与羧化速率的比值(Rpt/Vc)随着胞间CO2浓度的升高而呈下降的趋势,而不同光强下Rpt/Vc相对稳定,整体上未达到显著水平(P>0.05)。Using gas exchange method, the response of photorespiration of wheat to different light in- tensities and CO2 concentrations were estimated. The saturating light intensity of wheat flag leaf was 1 960.63 μmol·m^2.·s^-1 and 2 030.12μmol·m^2.·s^-1 for 21%O2 and 2%O2, respectively. The apparent photorespiration （Rp~） and total photorespiration （Rp~） of wheat increased as PAR increased from 50 to 800 mol·m^2.·s^-1, and then reached a steady state. There were no significant differences between Rpa and Rpt at different light intensities （P〈0.05）, which accounted for the low recovery of photorespiration CO2 at 380 μmol· mol^-1 CO2. As CO2 concentration increased, Rpa of wheat in- creased first, and then reached a maximum at 600 μmol·mol^-1 , while Rpt decreased with CO2 concentration increasing. There were significant differences between Rpa and Rpt when CO2 concentration was lower than 380 μmol· mol^-1 CO2 （P〈0.05）. The ratio of total photorespiration rate and carboxyla- tion rate （Rpt/Vc） deceased with CO2 concentration increasing, and had a small fluctuation at differ- ent light intensities （P〈0.05）, which indicated that suitable high light intensity and high CO2 con- centration were helpful to improve carboxylation rate （Vc）.

关 键 词：小麦 光呼吸 CO2浓度 光强 

分 类 号：S512.1[农业科学—作物学] S311