论文部分内容阅读
为了解农牧交错带油葵旺盛生长季光合作用日变化特征和光合“午休”原因,使用光合作用测量系统(LI-6400XT)于内蒙古武川试验站(2013年7月24日—7月28日)测定了晴天条件下油葵光合特性。结果表明:油葵光合速率日变化呈现典型的双峰曲线,具有明显的“午休”现象,且上午的峰值显著高于下午的峰值,观测期间平均高出11%。对油葵光合速率有显著影响的气象因子是光强和温度。蒸腾速率和气孔导度的日变化规律相似,也呈现双峰曲线,并且两者的峰值要早于光合速率的峰值。对气孔导度有显著影响的气象因子是光强和饱和水汽压差,对蒸腾速率有显著影响的气象因子是光强、饱和水汽压差和温度。油葵叶片的水分利用效率最高值出现在11:00,最高值为2.71g/kg。观测期间,在油葵光合速率下降的阶段均表现为胞间CO2浓度增加,气孔限制值下降。因此,造成该地区油葵光合“午休”的主要因素是非气孔因素。
In order to understand the diurnal variation characteristics of photosynthesis and the photosynthesis of photosynthesis and the reason of photosynthesis during the growing season of oil-sunflower in the ecotone between agriculture and animal husbandry, the photosynthesis measuring system (LI-6400XT) was used in Wuchuan Experimental Station of Inner Mongolia (July 24 -7 July, 2013) 28th) measured sunflower photosynthetic characteristics of the conditions. The results showed that: the diurnal variation of photosynthetic rate of oil sunflower showed a typical bimodal curve with obvious “lunch break ” phenomenon, and the morning peak was significantly higher than the afternoon peak, an average of 11% higher during the observation period. Meteorological factors that have a significant effect on the photosynthetic rate of oil sunflower are light intensity and temperature. The diurnal variation of transpiration rate and stomatal conductance were similar, showing a bimodal curve, and the peak values of both were earlier than those of photosynthetic rate. The meteorological factors that have a significant effect on stomatal conductance are the light intensity and the saturated water vapor pressure difference, and the meteorological factors that have a significant effect on the transpiration rate are the light intensity, the saturated water vapor pressure difference and the temperature. The highest water use efficiency of sunflower leaves appeared at 11:00, the highest value of 2.71g / kg. During the observation period, both the intercellular CO2 concentration increased and the stomatal limitation decreased when the photosynthesis rate of oil sunflower decreased. Therefore, the main contributor to the “lunch break” of oil sunflower in the area is non-stomatal factors.