4个美国紫菀品种光合生理特征比较

以4个美国紫菀Aster novae-angliae 品种1年生扦插苗为研究对象，研究了美国紫菀的光合生理特性。结果表明：4个美国紫菀品种的光补偿点与光饱和点各不相同，但光适应能力均较强。4个品种的光适应能力为紫球‘Purple Dome’＞香叶‘Herbstschnee’＞粉花‘Barr’s Pink’＞安德‘Andenken an Alma Potschke’；表观量子效率为香叶＞安德＞紫球＞粉花；暗呼吸速率为安德＞紫球＞香叶＞粉花。在春秋两季4个品种净光合速率日变化曲线均表现为单峰型，在夏季均为双峰型，春季峰值出现时间明显比夏、秋两季提前，夏季第1峰值均大于第2峰值，且有明显的光合“午休”现象。多元逐步回归分析表明，影响净光合速率的关键环境因子随花卉品种和生长季节不同而变化，主要包括光合有效辐射、空气温度及叶面温度。图3表3参21

Photosynthetic characteristics with four cultivars of Aster novae-angliae

One-year-old cuttings of four cultivars of Aster novae-angliae,＇ Purple Dome＇,＇ Herbstschnee＇,＇Barr＇s Pink＇,and ＇Andenken an Alma Potschke＇,were studied to determine their photosynthetic physio-ecological characteristics using a multivariate stepwise regression analysis.Results indicated that the light adaptive capacity was high and in the order：＇ Purple Dome＇ ＇ Herbstschnee＇ ＇Barr＇s Pink＇ ＇Andenken an Alma Potschke＇ with light compensation and saturation points differing.For apparent quantum yield,the order was：＇Herbstschnee＇ ＇Andenken an Alma Potschke＇ ＇ Purple Dome＇ ＇ Barr＇s Pink＇ ;and for the dark respiration rate it was：＇ Andenken an Alma Potschke＇ ＇Purple Dome＇ ＇Herbstschnee＇ ＇Barr＇s Pink＇.These four cultivars had strong diurnal changes in the net photosynthetic rate with single-peaked curves at midday in spring and autumn,but double-peaked curves in summer.These peak net photosynthetic rates were earlier in spring than in summer or winter.Double-peaked curves had greater initial peaks,and the photosynthetic noon break was strong at midday in summer （midday depression of photosynthesis）.A multivariate stepwise regression showed that the key environmental factors influencing the net photosynthetic rate included photosynthetically active radiation （PAR）,air temperature,and leaf temperature;however,these differed for each cultivar.