榕树光合特性的研究

Study on Photosynthetic Characteristics of Ficus Plants

采用便携式光合测定仪对琴叶榕、黑叶橡胶榕和斑叶橡胶榕3种榕树的净光合速率、蒸腾速率、气孔导度和胞间CO2浓度进行了分析测定.研究表明:3个榕树品种的净光合速率日变化曲线均为双峰型,且都存在明显的光合"午休"现象,最大净光合速率从大到小依次为黑叶橡胶榕、斑叶橡胶榕和琴叶榕;3个榕树品种日蒸腾速率、气孔导度的变化表现为单峰曲线;3个榕树品种的光饱和点从大到小依次为琴叶榕、斑叶橡胶榕和黑叶橡胶榕,而光的补偿点从大到小依次为黑叶橡胶榕、琴叶榕和斑叶橡胶榕.

In order to study the photosynthetic characteristics of three Ficus cultivars and provide theoretical support for their scientific planting,the diurnal variation of net photosynthetic rate（Pn）,transpiration rate（Tr）,stomata conductance（Gs）and intercellular carbon dioxide concentration（Ci）were measured with the LI-6400Portable Photosynthesis System.The results showed that the diurnal courses of photosynthesis in F.lyrata,F.elastica ‘Decora Burgundy’and F.elastica ‘Variegata’might be described with a double-peak curve and an obvious photosynthetic＂nap＂phenomenon was detected.The maximum net photosynthetic rate was in order of F.elastica ‘Decora Burgundy’〉 F.elastica ‘Variegata’〉 F. lyrata.The diurnal changes in transpiration rate and stomata conductance of all the three cultivars could be described with a single-peak curve.Their light saturation point（LSP）appeared in the order of F.lyrata 〉F.elastica‘Variegata’〉F.elastica‘Decora Burgundy’,and their light compensation point（LCP） in the order of F.elastica ‘Decora Burgundy’〉 F.lyrata 〉 F.elastica ‘Variegata’.