Effect of shading on light response curve of mixed lawn grass during the initial stage of establishment

In this study, the effects of different shade treatments(CK, 50%, and 70%) on the chlorophyll content and light response curves of Festuca arundinacea and Lolium perenne were studied using mixed turf grass. The objective of this study was to provide a basis for studying the internal mechanism of shade tolerance and maintenance management of turfgrass under shading conditions. The results indicated that:1) The content of chlorophyll a and carotenoids of F. arundinacea increased significantly under shade treatments,whilst the contents of chlorophyll b decreased significantly (P < 0.05). The content of chlorophyll a and chlorophyll b of L. perenne decreased significantly.The content of carotenoids increased significantly (P < 0.05); 2) With the increasing light intensity, the net photosynthetic rate (P_n) and stomatal conductance (G_s) of F. arundinacea and L. perenne both increased. With the increasing shading intensity, the P_n and G_s of F. arundinacea decreased, the change trends of L. perenne were the opposite; 3) The maximum assimilation rate (A_max), light compensation point (LCP) and light saturation point (LSP) of F. arundinacea significantly reduced under the shade treatments (P < 0.05), while the change trends of L. perenne were opposite. 4) Comprehensive analysis showed that F. arundinacea could adapt to shade stress by reducing its physiological activity rate, while L. perenne could adapt to shade stress by keeping the synthesis and decomposition of chlorophyll in a low dynamic balance. Moreover, L. perenne had stronger shade tolerance than F. arundinacea. In the shading environment of the cities, the sowing proportion of L. perenne could be increased appropriately to improve the visual quality of the mixed turf under shade conditions.