Zheng You-Fei, Ni Yan-Li, Mai Bo-Ru, Wu Rong-Jun, Feng Yan, Sun Jian, Li Jian, Xu Jing-Xin
Jiangsu Key Laboratory of Atmospheric Environmental Monitoring and Pollution Control High-tech Research, Nanjing 210044, China.
Ying Yong Sheng Tai Xue Bao. 2011 Jun;22(6):1457-64.
Taking winter wheat Triticum aestivum L. (cv. Yangmai 13) as test material, a field experiment was conducted in Nanjing City to study the effects of simulated reduced solar radiation on the diurnal variation of winter wheat flag leaf photosynthetic rate and the main affecting factors. Five treatments were installed, i. e., 15% (T15), 20% (T20) , 40% (T40), 60% (T60), and 100% (CK) of total incident solar radiation. Reduced solar irradiance increased the chlorophyll and lutein contents significantly, but decreased the net photosynthetic rate (Pn). Under different solar irradiance, the diurnal variation of Pn had greater difference, and the daily maximum Pn was in the order of CK > T60 > T40 > T 20 > T15. In CK, the Pn exhibited a double peak diurnal curve; while in the other four treatments, the Pn showed a single peak curve, and the peak was lagged behind that of CK. Correlation analysis showed that reduced solar irradiance was the main factor affecting the diurnal variation of Pn, but the physiological parameters also played important roles in determining the diurnal variation of Pn. In treatments T60 and T40, the photosynthesis active radiation (PAR), leaf temperature (T1) , stomatal conductance (Gs) , and transpiration rate (Tr) were significantly positively correlated with Pn, suggesting their positive effects on Pn. The intercellular CO2 concentration (Ci) and stomatal limitation (Ls) had significant negative correlations with Pn in treatments T60 and T40 but significant positive correlations with Pn in treatments T20 and T15, implying that the Ci and Ls had negative (or positive) effects on Pn when the solar irradiance was higher (or lower) than 40% of incident solar irradiance.
以冬小麦品种扬麦13（Triticum aestivum L. cv. Yangmai 13）为试验材料，在南京市进行田间试验，研究模拟太阳辐射减弱对冬小麦旗叶光合速率日变化及主要影响因素的影响。设置了5个处理，即分别为总入射太阳辐射的15%（T15）、20%（T20）、40%（T40）、60%（T60）和100%（CK）。太阳辐射减弱显著增加了叶绿素和叶黄素含量，但降低了净光合速率（Pn）。在不同太阳辐射强度下，Pn的日变化差异较大，日最大Pn依次为CK>T60>T40>T20>T15。在CK处理中，Pn呈现双峰日变化曲线；而在其他4个处理中，Pn呈现单峰曲线，且峰值滞后于CK处理。相关性分析表明，太阳辐射减弱是影响Pn日变化的主要因素，但生理参数在决定Pn日变化中也起重要作用。在T60和T40处理中，光合有效辐射（PAR）、叶片温度（T1）、气孔导度（Gs）和蒸腾速率（Tr）与Pn显著正相关，表明它们对Pn有正向影响。在T60和T40处理中，胞间CO2浓度（Ci）和气孔限制（Ls）与Pn显著负相关，而在T20和T15处理中与Pn显著正相关，这意味着当太阳辐射强度高于（或低于）入射太阳辐射的40%时，Ci和Ls对Pn有负（或正）向影响。
