丹参光合日变化的研究

丹参光合作用的光补偿点与光饱和点约为97.9μmol.m-2.s-1和1 100μmol.m-2.s-1。丹参叶片光合日变化曲线呈明显双峰型,峰值分别出现在上午10时和下午14时左右,在高光强下中午有明显"午休"现象。光系统Ⅱ光化学效应(Fv/Fm)在晴天中午明显降低,说明田间丹参叶片在晴天中午经常发生光抑制,高光强和高温是发生光抑制的主要原因。自然条件下,强光引起的光抑制可能是丹参叶片光合速率午间降低的重要原因之一。

Research on Diurnal Changes of Photosynthesis in Salvia miltiorrhiza

The light compensation point and light saturation point of Salvia miltiorrhiza were approximately 97.9 mol·m-2·s-1and 1 100 mol·m-2·s-1 respectively.The diurnal change of photosynthesis in the leaves of Salvia miltiorrhiza was a double-peak curve and the peaks appeared at 10∶00 and 14∶00 respectively.There was the distinct phenomenon of "noon break" under the condition of strong light.The photochemistry effect(Fv/Fm) of light system Ⅱ decreased apparently at sunny day noon,which showed that photoinhibition often occurred in Salvia miltiorrhiza leaves in the field,and the strong light and high temperature were main causes.Under the natural condition,the photoinhibition caused by strong light may be one of the important reasons for the decrease of photosynthesis in Salvia miltiorrhiza leaves.