不同季节茶条槭光合特性的差异

以3年生茶条槭为试验材料,在田间条件下研究不同季节光合作用的变化规律,同时对夏秋2季茶条槭叶片光合作用日变化进行了比较。结果表明:茶条槭叶片净光合速率季节变化呈不对称"双峰"曲线,峰值分别出现在7月和9月;夏秋季茶条槭叶片净光合速率和气孔导度的日变化均呈"单峰"曲线,峰值均出现在11:00时左右,但秋季净光合速率和气孔导度均明显高于夏季。对不同季节光合日变化参数的比较结果表明:夏秋季各个时段日温差为7.23~16.87℃;秋季相对湿度明显高于夏季;光合有效辐射夏季高于秋季,夏季峰值出现在11:00时左右,而秋季峰值出现于在9:00时左右;夏秋季节胞间CO2体积分数日变化趋势大致相同,各时段胞间CO2体积分数秋季均高于夏季;饱和蒸气压的日变化夏季各时段均高于秋季,但夏季饱和蒸气压是逐步上升曲线,而秋季日变化则是缓慢下降趋势。通过以上分析认为,茶条槭光合能力有季节性的适应,秋季低温季节仍具有较高的光合能力,并具较高的观赏价值。

Difference in Photosynthetic Characteristics of Acer ginnala in Different Seasons

The seasonal change rules of photosynthesis of three-year-old Acer ginnala were studied in the field,and daily photosynthesis variations of leaves in summer and autumn were compared.Results indicated that the seasonal variation of net photosynthetic rate of A.ginnala leaves showed a double-peak curve,and the peaks appeared at July and September.Daily variations of net photosynthetic rate and stomatal conductance of A.ginnala leaves in summer all exhibited single-peak curves,and the peaks all appeared at 11:00 or so,but net photosynthetic rate and stomatal conductance of A.ginnala leaves in autumn were higher than those in summer.Parameters for daily variation of photosynthesis in different seasons showed that daily temperature differences in summer and autumn were between 7.23 degrees C and 16.87 degrees C.The relative humidity in autumn was higher than that in summer.Photosynthetic active radiation of A.ginnala leaves in summer was higher than that in autumn,and the peak appeared at 11:00 in summer and at 09:00 in autumn.The tendencies of daily variations of intercellular CO2 concentration were roughly the same,and the intercellular CO2 concentration at each period of time in autumn was higher than that in summer.The daily variation of saturation vapor pressure at each period of time in summer was higher than that in autumn,but saturation vapor pressure displayed a gradually increasing tendency in summer and a slowly decreasing tendency in autumn.The photosynthetic abilities of A.ginnala with seasonal adaptability are still higher under low temperatures in autumn,so A.ginnala has higher view value.