郁闭林分下华重楼光合特性研究

Study on photosynthetic characteristics of Paris polyphylla Smith var. chinensis(Franch.) Hara in closed stand

林药模式是最具林业特色的林下经济发展模式之一,而发展好林药首先就必须选择出适宜在林荫下生长的道地品种、大宗品种。本文以在郁闭林分中正常生长的华重楼健康植株为材料,运用Li-6400便携式光合作用测定系统对其光合作用日变化、光响应特性及CO_2响应特性进行研究。结果表明:华重楼光合作用日变化表现为典型的双峰曲线,具有明显的午休现象,且既受气孔因素限制,也受非气孔因素限制。影响华重楼光合日变化的主要因子为大气CO_2浓度和叶面大气压亏缺等。华重楼的光补偿点为3.93μmol·m^(-2)s^(-1),光饱和点为455μmol·m^(-2)s^(-1),表观量子效率为0.067 3μmol·m^(-2)s^(-1),验证了华重楼为典型的阴生植物,且利用弱光的能力较强。华重楼CO_2补偿点为168.31μmol·mol-1,CO_2饱和点为2 225μmol·mol-1,羧化速率为0.008 9μmol·mol-1,为典型的C3植物。

Forest-medicinal plant mode is one of the most characteristic modes of under-forest economy. However,the one of the most crucial measure to accelerate the development of forest-medicinal plant mode is to select the typical Chinese material medical,or bulk commodity varieties,which are adapt to grow in closed stand. In this paper,the diurnal variation of photosynthesis,light-response curve,and CO2-response curve of Paris polyphylla Smith var. chinensis Hara were surveyed using Li-6400 portable photosynthesis system in close stand. The results showed as following： The diurnal variation of photosynthesis of P. polyphylla Smith var. chinensis Hara represented double-peak curve with obvious midday-depression,which were affected both stomatal factor and the non-stomatal one. And the correlation and regress analysis showed that the main affecting factors of diurnal variation of photosynthesis were atmosphere CO2 concentration and Vpdl. The light compensationpoint（LCP）,light saturation point（LSP） and apparent quantum efficiency（AQY） are 3. 93 μmol·m-2s-1,455μmol · m-2s-1, and 0. 067 3 μmol · m-2s-1, respectively, which indicated that P. polyphylla Smith var. chinensis Hara was the typical shade plant, and has a higher capability of utilizing low light. The CO2-compensation point（CCP）, CO2-saturation point（CSP）, and carboxylation efficiency（CE） were 168. 31μmol·mol-1,2 225 μmol · mol-1,and 0. 008 9 μmol · mol-1,respectively,which suggested that Paris polyphylla Smith var. chinensis Hara was the typical C3 plant.