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作 者 ：谷艳芳,高志英,邢倩,丁圣彦

期 刊 ：生态学报 2007年 27卷 8期 页码：3465~3471

关键词：冬小麦旗叶；净光合速率；蒸腾速率；生理生态因子；黄淮海平原；

Keywords:flag leaf of winter wheat, photosynthesis rate, transpiration rate, ecohysiological factors, HuangHuaiHai Plain,

摘 要 ：分别于2005年和2006年4、5月份，在中国科学院封丘农业生态试验站用Li-6400光合测定仪对田间冬小麦（Triticum aestivum）进行了净光合速率（P_n）、蒸腾速率（T_r）日变化的测定，并同步测定了有效辐射（PAR）、气温（T_a）、叶温（T_l）、空气相对湿度（R_h）、气孔导度（G_s）、胞间CO₂浓度（C_i）等因子，研究了冬小麦旗叶的P_n、T_r与环境和生理因子之间的关系。结果表明，冬小麦旗叶的P_n随PAR的增加而升高，其光补偿点和光饱和点分别在50~60 μmol•m^-2 •s^-1和1050~1100 μmol•m^-2 •s^-1左右；T_r随 PAR呈线性升高。T_a与T_l的相关系数r=0.886**，达显著水平，冬小麦旗叶P_n随T_a、Tl的增加而升高，当T_a、T_l分别超过30 ℃、32 ℃左右时，P_n随两因素的增加反而下降；T_r随T_a、Tl的增加呈直线升高。冬小麦旗叶P_n、T_r与G_s的相关系数分别为r=0.407**和r=0.322**，二者均随G_s的增加而升高，当Gs超过0.2 mol•m^-2 •s^-1左右时，P_n的速度就会减缓。冬小麦旗叶的P_n、T_r均随Ci的增加而下降。通过对生态、生理因子的多元回归分析表明，影响黄淮海平原冬小麦旗叶的P_n、Tr的主要因子是PAR、G_s，除此以外，C_i也是影响P_n的重要因子。

Abstract:Photosynthesis and transpiration of flag leaf of winter wheat in Feng-qiu Agricultural Experiment station of CAS were measured at different growing stages with model Li-6400 photosynthesis system. In addition, variables such as the leaf temperature, photosynthesis active radiation, relative humidity, stomatal conductance, intercellular CO₂ concentration were also measured. This experiment studied the relations between the net photosynthesis rate & transpiration rate of flag leaf and ecological & physiological factors. The results showed that P_n of flag leaf rose when PAR increased, the light compensation point of photosynthesis (Ic) and light saturation point of photosynthesis (Isat) in flag leaves were respectively about 50-60 μmol•m^-2 •s^–1 and 1050-1100 μmol•m^{- 2} •s ^-1; T_r of flag leaf showed a positive linear correlation with PAR. The relative coefficient between T_a and T_l was 0.886**, P_n of flag leaf rose as T_a and T_l increased, then began to decrease when T_a and T_l exceeded 30 ℃ and 32 ℃ respectively; T_r of flag leaf showed a positive linear correlation with T_a and T_l. Relative coefficient between P_nand Gs was r=0.407**, relative coefficient between T_r and Gs was r=0.322**; both first rose while Gs increased, then decreased when Gs exceeded 0.2 mol m- 2 s -1. P_n and T_r decreased when Ci increased. PAR and Gs were the dominant factors affecting plant photosynthesis and transpiration.

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