不同刺槐品种光合光响应曲线的温度效应研究

采用Li-6400便携式光合测定仪分别测定了25、30、35℃等3个温度条件下3个刺槐品种的光合光响应特征曲线,并选用直角双曲线修正式对光响应曲线进行拟合。结果表明:1)温度对不同刺槐品种光合光响应曲线变化规律具有显著影响,普通刺槐和红花刺槐在25℃时光饱和点高,而四倍体刺槐在35℃时光饱和点高,说明四倍体刺槐对高温的适应能力相对较强;2)总体上,不同刺槐品种的最大净光合速率、光能利用效率及初始量子效率随着温度梯度的升高,均有所下降,光补偿点及暗呼吸速率随温度的变化规律不明显。

Influence of air temperatures on photosynthetic light-response curves of Robinia pseudoacacia L

The photosynthetic light-response curves of diploid Robinia pseudoacacia,R.pseudoacacia var.decaisneana and tetraploid R.pseudoacacia under three temperature treatments,i.e.25,30,35℃,were measured using a Li-6400 portable photosynthesis system.A modified rectangular hyperbola was adopted to fit the light-response curves.The photosynthetic light-response curves among the three cuhivars differed significantly with changes in temperature.Diploid R.pseudoacacia and R.pseudoacacia var.decaisneana had a relatively high light saturation point at a temperature of 25℃,while tetraploid R.pseudoacacia had higher light saturation point at 35℃.indicating that the tetraploid R.pseudoacacia had a stronger adaptability to high temperature than do the other cuhivars.In general,the maximum net photosynthetic rate,light use efficiency and initial quantum yield of these three R.pseudoacacia cultivars decreased with an increase in temperature.However,their light compensation point and dark respiration rate did not change markedly.