新疆杨幼苗光合特性研究

Photosynthetic Characteristics of Young Populus alba var.pyramidalis Bge.

利用Li-6400便携式光合仪对3年生新疆杨幼苗的光合生理指标进行了测定。结果表明:在生长季的各个月份,新疆杨幼苗的净光合速率日变化均呈"单峰型"曲线,各月份的净光合速率日最高值出现的时间存在一定差异。各个月份新疆杨幼苗的蒸腾速率日变化趋势基本一致,早晨较高,随着时间的延长,曲线开始呈现下降趋势,到20:00达到最低,蒸腾的变化与日温度的关系较为明显。各个月份试验地的光强日变化趋势基本一致,新疆杨幼苗对强光的适应能力较强。在6—9月,各个月份新疆杨的瞬时水分利用效率日变化趋势基本一致,呈现较明显的"单峰型"曲线。新疆杨幼苗生长季光合指标月变化情况与当地的自然环境有一定关系。

The photosynthetic physiological indexes of 3-year-old Populus alba var.pyramidalis Bge.were determined by Licor-6400 portable photosynthesis apparatus.Result shows that:The diurnal variation curves of net photosynthetic rate of seedlings are the'single peak'curves in the growing season,and there is a certain difference in the daily maximum net photosynthetic rate.The diurnal variation trend of transpiration rate of Populus alba var.pyramidalis Bge.seedlings in different months is basically the same in the morning,and the curve began to show a decreasing trend with time,reaching the lowest point at 20:00.The relationship between transpiration &daily temperature is obvious.The diurnal variation trend of light intensity in experimental days is consistent,and the analysis of photosynthetic data shows that Populus alba var.pyramidalis Bge.seedlings have better adaptability to stong light.In the period from June to September,the diurnal variation trend of instantaneous water use efficiency of Populus alba var.pyramidalis Bge.is consistent with each other,showing a distinct'single peak'curve.The monthly variation of photosynthetic index of Populus alba var.pyramidalis Bge.seedling season is related to the local natural environment.