光皮树优良无性系光合生理特性对光强的响应

Response of photosynthetic physiological characteristics of superior clones of Cornus silsoniana Wanager to light intensity

采用LI-6400便携式光合测定系统对光皮树优良无性系光合生理特性对光强的响应进行了研究。结果表明：①13个光皮树优良无性系具有较高的LCP（20．7～64．7μmol·m^-2·s^-1）、较低的LSP（349．7～563．9μmol·m^-2·s^-1）和较弱的最大光合作用能力，对弱光的利用能力较弱，对多种光照环境的适应性较差。光皮树优良无性系对弱光的利用能力大为G-13〉G-14〉G-3〉G-10〉G-2〉G-8〉G-15〉G-7〉G-9〉G-11〉G-6〉G-4〉G-5，对强光利用能力的大小为G-14〉G-6〉G-10〉G-9〉G-15〉G-4〉G-13〉G-2〉G-11〉G-7〉G-5〉G-8〉G-3：②13个光皮树优良元性系的表观量子效率在5月份的变化范围为0．0194～0．0317，比-般植物的小（0．03～0．05）；③影响光皮树不同无性系净光合速率的主要生理生态因子为胞间C02浓度（Ci）、光照强度（PaR）、蒸腾速率（Tr）、气孔导度（白）等。Ci为光皮树无性系净光合速率的第-影响因子，PAR、Tr、Gs的影响在其次，PAR对Pn起主要调节作用。

The response of photosynthetic physiological characteristics of superior clones of Comus silsoniana Wanager to light was studied with the Licor - 6400 portable photosynthetic system. The results showed as following： （ 1 ） Thirteen superior clones of C. Wanager have a high LCP LCP（20.7～64.7μmol·m^-2·s^-1） , a low LSP（349.7～563.9μmol·m^-2·s^-1） and a weak largest-ability of pho- tosynthesis. The utilization ability was weak for weak light and adaptability to various light environments was poor. The utilization ability of superior clones of C. Wanager for weak light from high to low was G-13 〉 G-14 〉 G-3 〉 G-10 〉 G-2 〉 G-8 〉 G-15 〉 G-7 〉 G-9 〉 G-11 〉 G-6 〉 G-4 〉 G-5, the utilization ability for strong weak light from high to low was G-14 〉 G-6 〉 G-10 〉 G-9 〉 G-15 〉 G-4 〉 G-13 〉 G-2 〉 G-11 〉 G-7 〉 G-5 〉 G-8 〉 G-3. （2） The range of apparent quantum efficiency of thirteen superior clones of C. Wanager was 0.0194 - 0.0317 in May, it is less than normal plants （0.03 -0.05 ）. （3） The main eco-physiology factors which influence the net photosynthetic rate of different clones of C. Wanager were Ci, PAR, Tr and Gs. Ci was the first factor influencing on the net photosynthetic rate of C. Wanager clones, PAR, Tr and Gs follows. PAR play a major regulating role in Pn.