丘间滩地糜子和玉米光合蒸腾特性与内外影响因子的关系

对种植在丘间滩地的糜子和玉米进行了光合、蒸腾及一系列内外影响因子的测定。结果表明:两种作物光合、蒸腾日进程曲线均呈单峰型;蒸腾速率达峰值的时间落后于光合速率达峰值的时间;光合速率主要受光合有效辐射和温度的影响;蒸腾速率主要受空气湿度和气孔导度的调控;光合、蒸腾受植物叶水势和胞间CO₂浓度的影响不大。两种作物光合与蒸腾特性、水分利用效率及内部调解机制的变化极为相似,只是在光合速率、水分利用效率和对高温的适应上,糜子略优于玉米。

PHOTOSYNTHETIC AND TRANSPIRATING PROPERTIES OF PANICUN MILIACEUM L. AND ZEA MAYS L. ON INTERDUNAL LAND AND THEIR RELATIONSHIPS WITH EXTERNAL AND INTERNAL FACTORS

The experiment was conducted in the northeastern part of Mu Us Sandy Land, which belonged to the transition zone of arid and semiarid region. The experimental materidals are Panicum miliaceum L. and Zea mays L. planted on interdunal land. The LI-6000 photosynthesis analysing system was used to measure the photosynthetic rate, traspirating rate, photosynthetic effective radiation, relative air humidity, leaf temperature, airtemperature, inter-celler CO₂ concentration and stomate preventing force. As for leaf water potential, it was measured with pressure-room method. The dating time is at jionting stage and when the day is suny and no wind. Five health plants from every species and three leaves from each plant are choiced for determination. Each result is the average datum of five dating. The analysing results from research showed that the diurnal photosynthesis and transpiration curves of these two plants are all one-peak type; the time of transpiration peak value appearing is after that of photosynthesis peak value appearing; the photosythetic rate is predominately controlled by effective radiation and temperature, while the transpiration rate by air humidity and stomatal conductivity; both photosynthesis and transpiration rates are less decided by leaf water potential and intercellar CO₂ concentration; the two plants have similar photosynthesis and transipiration properties, water use efficiency and internal adjusting mechanism, except for narrow advantage of Panicum miliaceum L. on photosynthesis rate, water use efficiency and adaptability to high temperature compared with Zea mays L..