中文摘要：

为探讨三七（Panax notoginseng）对不同光照强度的生理生态适应机制,本研究以二年生三七为材料,研究其在不同光照强度下的生长特性、叶片解剖结构、生物量积累与分配以及光合生理特性.结果表明：处理120d后,透光率为5.10％荫棚下三七株高、叶面积、茎粗均显著高于其他遮阴处理（P＜0.05）.随着光强降低,三七叶片厚度、栅栏组织厚度、海绵组织厚度、根生物量比、气孔导度、蒸腾速率均随之减小,而其叶生物量比、茎生物量比及水分利用速率却随之增大.透光率为46.5％ ～5.10％荫棚下,随着透光率的减小,三七净光合速率随之增大,暗呼吸速率随之减小,但在最低透光率2.80％的环境下,三七其净光合速率反而减小,暗呼吸速率反而增大.综合来看,三七表现出典型喜阴植物的特征,在光照强度相对较低的生长环境下三七的净光合速率较高,生长表现较好,根生物量积累较多.

英文摘要：

To examine eco-physiological adaptation of Panax notoginseng to a light gradient,the growth pattern,leaf anatomy,biomass accumulation and distribution,and photosynthetic characteristics were analyzed in P.notoginseng grown under 46.5%,21.8%,9.70%,5.10% and 2.80% of full sunlight.The plant height,leaf area,and stem diameter of P.notoginseng under 5.10% of full sunlight were higher than those growing under the other light levels after 120 days of treatment （P 〈 0.05）.The thickness of palisade,sponge and leaf,root biomass ratio,stomatal conductance,and transpiration rate of P.notoginseng decreased,however,the leaf biomass ratio,stem biomass ratio,and water use efficiency increased with light levels decreasing.The net photosynthetic rate of P.notoginseng increased with light levels decreasing from 46.5% to 5.10% of full sunlight,however,the dark respiration rate decreased.In contrast,under 2.80% of full light,photosynthetic rate decreased and dark respiration increased.The results obtained here suggest that the proper light intensity promotes the photosynthesis and root biomass accumulation,thus improves the growth of P.notoginseng.