摘要
选用A-65/27、A-65/31及A-61/1863个半常绿-常绿杨树品系,比较了其光合速率日变化特征及光合速率的光响应和CO2响应特性.结果表明:A-65/27及A-65/31的光合日变化呈现明显的双峰型,存在明显的光合午休现象,而A-61/186的净光合速率日变化表现为一降不起型,峰值出现在10:00左右,此后一直保持下降趋势;3个品系的最大光合速率及光饱和点由大到小的次序为A-61/186、A-65/31及A-65/27,而反映植物对弱光利用能力的光补偿点(LCP)和表观量子效率(a)的值的大小次序为A-65/27、A-61/186和A-65/31;在CO2低浓度时,同一浓度下3个品系光合速率由大到小的顺序为A-61/186、A-65/27及A-65/31,即与羧化效率(CE)值一致,而在CO2高浓度时,三者的光合速率由高到低的次序为A-65/27、A-61/186及A-65/31;CO2补偿点(Γ)及光呼吸速率(Rp)表现出相同的趋势,均是A-65/27的值最大,其余依次是A-61/186及A-65/31.
Photosynthetic characteristics of three semi evergreen-evergreen poplar clone A-65/27, A-65/31 and A-61/186 were investigated. Diurnal variation in photosynthesis, changes in net photosynthesis rate （Pn） to photon flux density and CO2 concentrations （Ca） were determined. Diurnal Pn curves in A-65/27 and A-65/31 showed two peaks, with obvious midday depression in photosynthesis. Pn changes in A-61/186 was a single-peaked curve with peak value at 10：00 AM, with Pn continued to decline after this time. Pmax and light saturation point were therefore in declining order： A-61/186, A-65/31 and A-65/27. Whereas light compensation point and apparent quantum yield in declining order were ： A-65/27. A-61/186 and A-65/31. When CO2 concentration was low, Pn was in the following declining order： A-61/186.A-65/27, A-65/31, and which was the same as carboxylation efficiency （CE）. However, when CO2 concentration was high, Pn order became： A-65/27.A-61/186 and A-65/31. CO2 compensation point （F） and photorespiratory rate（Rp）showed the same trend, with the highest seen in A-65/27, A-61/186 in the middle, and with the lowest in A-65/31.
出处
《北京师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第4期424-428,共5页
Journal of Beijing Normal University(Natural Science)
基金
国家林业局948项目资助(2003-4-07)
福建省自然科学基金资助项目(2007J0332)
关键词
光合效率
光合响应
半常绿-常绿杨树
photosynthetic efficiency
photosynthetic response
semi evergreen-evergreen poplar clone
