Abstract: A study on the photosynthetic physiological characters of the vegetative tillers and reproductive tillers of Axonopus compressus reveal that the net photosynthetic rate (Pn) and the water use efficiency (WUE) of the former are higher than those of the latter, while the respiration rate and the light compensation point (LCP)of the reproductive tillers are higher than those of vegetative tillers. Moreover, the reproductive tillers’ basal leaves are weak in photosynthetic capacity and their respiratory intensity is intermediate-stronger than that of the vegetative tillers but weaker than the respiratory intensity of the flag leaves of the reproductive tillers. As the apparent quantum yield (AQY) of modules of the two tillers of Axonopus compressus are higher than those of plants in general, the lawn grass thrives in the dim light and adapts itself to a shady habitat. The vapor pressure deficit (VID) of leaves is mended through the stomatal conductance(Gs) to modulate the loss of water by the feedback of transpiration(Tr).in the intense light, the stomatal conductance of modules of the two tillers descend gradually, but their transpiration rate and vapor pressure deficit continue to increase linearly. The fact shows that Axonopus compressus lacks a water-retaining machanism and is more adaptable to a water-saturated habitat.

Key words: Grassland science, Axonopus compressus, Vegetative tiller, Reproductive tiller, Module, Photosynthetic physiology, Lawn

摘要： 研究地毯草营养枝与生殖枝的光合生理特性。结果表明:前者叶片的光合及水分利用效率均高于后者,而呼吸速率和光补偿点低则低于后者,其中生殖枝基部叶片光合能力较弱,呼吸强度居于营养枝与生殖枝旗叶之间;地毯草表观光量子效率高于一般植物,适合阴生环境条件;营养枝和生殖枝的叶面饱和水汽压亏缺是通过气孔导度对蒸腾速率所引起的水分散失进行反馈调节,在强光下气孔导度逐渐下降,但蒸腾速率和叶面饱和水汽压亏缺始终保持线性增加趋势,缺乏保水机制,更适合水分充足的环境条件。

关键词: 草原学, 毯草, 营养枝, 生殖枝, 构件, 光合生理, 草坪植物