细柄蕈树苗期光合生理特性研究

Research on Photosynthetic Physiological Characteristics of Altingia gracilipes During Seedling Stage

在盆栽条件下以3株细柄蕈树壮苗为研究对象,利用LCPRO+便携式光合作用测定系统对其光合作用日变化及光响应进行测定和分析,结果表明:细柄蕈树的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)的日变化曲线均为单峰曲线,无"光合午休"现象,是一种高光效树种;水分利用率(WUE)和气孔限制值(Ls)日变化曲线最大值都在9:00时,17:00时后急剧下降;胞间CO2浓度(Ci)日变化曲线趋势与Ls恰好相反。Pn与光合有效辐射(PAR)、Tr成极显著正相关,与Ci呈极显著负相关,与其他因子相关不显著,说明Pn与内部自身因素关系更大。细柄蕈树有较高的光饱和点(LSP)、光补偿点(LCP)和表观量子效率(AQY),为典型的阳性树种,对强光利用能力强,对弱光利用效率高,环境的适应性强。

Under the condition of potted planting, with three Altingia gracilipes seedlings as the researchobjects, the LCPRO＋ Portable photosynthesis measuring system was used to measure and analyze the dailychanges of photosynthetic and the light response of Altingia gracilipes. The results showed that the diurnalvariation curve of Altingia gracilipes＇ net photosynthetic rate（Pn）, transpiration rate（Tr）, stomatalconductance（Gs） all appeared as single peak, showed no＂midday rest＂phenomenon, proved it to be a speciesof high photosynthetic efficiency. The maximum of diurnal variation curve of water use efficiency（WUE） andlimiting value of stomata（Ls） came out in 9 am, and decreased rapidly from 5 pm. The diurnal variation curveof intercellular CO2 concentration（Ci） tended to be the exact contrary to that of Ls. Pn, and showed a highlysignificant positive correlation with photosynthetically active radiation（PAR） and Tr, and a highly significantnegative correlation with Ci, rather than other factors, Pn connected more obviously with its inside own factors.In conclusion, Altingia gracilipes has high light saturation point（LSP）, light compensation point（LCP）, andapparent quantum yield（AQY）, known as a kind of typical heliophilous tree species. Altingia gracilipes has astrong capability of making use of high light, as well as a high efficiency of using low light, and has goodenvironmental adaptability.