Comparative Studies on Light Utilization Characteristics and Shade Tolerance of 7 Climbing Shrub Species

The light-light curve and CO2 curve of 7 potted climbing shrub species,Wisteria sinensis, Euonymus fortunei,Parthenocissus tricuspidata, P. quinquefolia, Polygonum aubertii,Campsis radicans and Lonicera japonica, were determined by Dysprosium light illumination. Light compensation point （LCP）, light saturation point （LSP）, Pn,Φ,CO2 compensation point and RuBisco relativity of the 7 climbing shrub species were analyzed comparatively. The correlation of shade tolerance with Pn,Φ and CO2 utilization ability were discussed by multi-factor analyzing. The results showed that different climbing shrub specie had different light utilization characteristics. Euonymus fortunei, Lonicera japonica and Parthenocissus quinquefolia had low LCP, meanwhile they had lower LSP. They could use low light quantum, and had strong shaded-tolerance. Polygonum aubertii had limited shaded-tolerance because of its low LCP and high LSP, broader light quantum could be used effectively. Wisteria sinensis, Campsis radicans and Parthenocissus tricuspidata had higher LCP and LSP, they were sun climbing shrub. A significantly positive correlation was found between LCP and Pn,LCP and RuBisco relativity. A negative correlation was found between LCP and Φ. The ability of shade-tolerance of the 7 climbing shrub species followed the order of Euonymus fortuneiLonicera japonica=Parthenocissus quinquefoliaPolygonum aubertiiWisteria sinensisParthenocissus tricuspidataCampsis radicans.