铁线莲属植物光合特性研究
Study on Photosynthetic Character of Clematis

采用LI 6400便携式光合仪，对种植于浙江农林大学铁线莲种植资源圃6种铁线莲的光合特性进行测定与系统比较。结果显示:6种铁线莲属植物光补偿点（LCP）为13.20~81.96 μmol·m-2·s-1，光饱和点（LSP）为1 230.77~1 364.41 μmol·m-2·s-1，表明供试种类可有效利用强光进行光合作用。野生种类的最大净光合速率（Pnmax）和表观量子效率（AQY）均显著高于栽培品种。供试的铁线莲属植物净光合速率（Pn）日变化均呈“单峰”曲线，其中毛萼铁线莲的Pnmax出现在午后光强和气温最高时，其具有良好的强光高温适应性。相关性分析表明，外界光强（PAR）和叶片蒸腾速率（Tr）与Pn达显著或极显著相关水平，是影响铁线莲光合速率日变化的主要因子。
The photosynthetic parameters of 6 different varieties of Clematis were determinated and systemically compared by using Li-6400 portable photosynthesis system. The results showed that light compensation point (LCP) of 6 different varieties of Clematis were about 13.20-81.96 μmol·m-2·s-1, light saturation point ranged from 1 230.77 to 1 364.41 μmol·m-2·s-1. The Pn and AQY of 3 wild species were higher than that of cultivated varieties. The diurnal changes of photosynthetic rate of tested varieties presented a single-apex curve, of which C. hancockiana could well adapt to strong light and high temperature at pereiod of highest temperature and illumination intensity after noon. The analysis results showed that net photosynthetic rate had significant or extremely significant correlation between PAR and Tr. They were two main factors affected the diurnal change of Pn.