冬小麦光合作用和叶绿素荧光特性的研究

随着小麦收获指数的提高，高光效育种将是小麦产量进一步提高的主要育种手段，通过分析210份小麦材料拔节期、抽穗期、灌浆后期3个生理阶段的光合生理特性和叶绿素荧光特性，探讨了小麦不同光合指数和叶绿素荧光指数相互之间的相关关系，以期为小麦高光效育种提供一些理论依据。研究结果表明，小麦拔节期、抽穗期、灌浆后期光合速率平均值分别为13.49 μmol/(m2?s)、16.22 μmol/(m2?s)、7.83 μmol/(m2?s)，变异范围分别为0.70~22.06 μmol/(m2?s)、5.59~25.17 μmol/(m2?s)、0.82~17.1 μmol/(m2?s)；胞间CO2浓度平均值分别为222.1 vpm、200.5 vpm、232.9 vpm，变异范围分别为153.0~330.3 vpm、147.0~275.7 vpm、156.8~321.0 vpm；蒸腾速率平均值分别为3.41 mmol/(m2?s)、4.45 mmol/(m2?s)、3.28 mmol/(m2?s)，变异范围分别为0.67~6.55 mmol/(m2?s)、1.97~7.33 mmol/(m2?s)、1.03~6.22 mmol/(m2?s)；气孔导度平均值分别为0.18 mol/(m2?s)、0.20 mol/(m2?s)、0.10 mol/(m2?s)，变异范围分别为0.02~0.44 mol/(m2?s)、0.05~0.52 mol/(m2?s)、0.02~0.27 mol/(m2?s)；叶面温度平均值分别为27.5℃、32.2℃、34.7℃，变异范围分别为18.4~36.4℃，23.2~37.1℃，25.5~42.9℃。小麦拔节期和抽穗期的初始荧光平均值分别为91.9、40.5，变异范围分别为49.33~125.33、17.67~63.67，最大荧光平均值分别为522.6、224.3，变异范围分别为287.6~668.7、84.3~375.3；PSⅡ最大光化学量子产量平均值都为0.82，变异范围分别为0.78~0.88、0.75~0.88。相关分析表明，不论是拔节期、抽穗期还是灌浆后期，光合速率都与气孔导度和蒸腾速率显著正相关。在小麦抽穗期光合速率与胞间CO2浓度相关不显著，但在拔节期和灌浆后期光合速率与胞间CO2浓度显著或极显著负相关，气孔导度与胞间CO2浓度和蒸腾速率在小麦3个生理时期都呈正相关，且大部分达到了极显著水平，胞间CO2浓度与蒸腾速率在拔节期和灌浆后期呈显著负相关；通过叶面温度与其他光合指标的相关分析，推断小麦的最佳光合温度为20℃左右；通过对小麦叶绿素荧光指标与小麦光合指标的相关性分析，发现小麦在抽穗期其光合性能更易受环境条件的影响，因此应该在小麦抽穗期加强小麦光合生理指标稳定性的选择。

Research on the Photosynthesis and Chlorophyll Fluorspar Characteristic of Winter Wheat

With the improvement of wheat harvest index, the high photosynthetic efficiency breeding will be the main means to further improve wheat yield. In this paper, wheat photosynthesis and chlorophyll fluorescence characteristics in three physiological stages including jointing, heading, and late filling stage were studied by 210 materials. Additional, the correlation of wheat photosynthesis and chlorophyll fluorescence indices were analyzed. The results showed that wheat’s photosynthetic rate averages in jointing, heading, and late filling stage were respectively 13.49, 16.22 and 7.83 μmol/(m2·s), variation ranges were 0.70-22.06, 5.59-25.17 and 0.82-17.1 μmol/(m2·s); intercellular CO2 concentration averages were 222.1, 200.5 and 232.9 vpm, variation ranges are 153.0-330.3, 147.0-275.7, 156.8-321.0 vpm; transpiration rate averages were 3.41, 4.45, 3.28 mmol/(m2·s), variation ranges were 0.67-6.55, 1.97-7.33, 1.03-6.22 mmol/(m2·s); stomatal conductance averages were 0.18, 0.20, 0.10 mol/(m2·s), variation ranges are 0.02-0.44, 0.05-0.52, 0.02-0.27 mol/(m2·s); leaf temperature averages were 27.5℃, 32.2℃, 34.7℃, variation ranges are 18.4-36.4℃, 23.2-37.1℃, 25.5- 42.9℃; initial fluorescence averages mean in jointing and heading stage were 91.9, 40.5, variation ranges are 49.33-125.33, 17.67-63.67, maximal fluorescence averages are 522.6, 224.3, variation ranges were 287.6668.7, 84.3-375.3, all the averages of maximal photochemical quantum yield of PS II was 0.82, the range of variation were 0.78-0.88, 0.75-0.88. Correlation analysis showed that no matter jointing and heading stage or late filling stage, photosynthetic rates were positively correlated with stomatal conductance and transpiration rate, the correlation between photosynthetic rate and intercellular CO2 concentration was not significant in wheat heading stage, but in the jointing and late filling stage the correlation was significantly negative; stomatal conductance, intercellular CO2 concentration and transpiration rate were all positive correlation in wheat three physiological periods, and most reached a significant level; the negative correlation between intercellular CO2 concentration and transpiration rate in the jointing and post-grouting stage reached a significant level too. By correlational analyses between leaf temperature and other photosynthetic indexes, we conclude that the best temperature of wheat photosynthesis was about 20℃; and by correlational analysed between photosynthesis and chlorophyll fluorescence indices, we think that the stability selection of wheat photosynthetic performanceshould be strengthened in heading stage.