Comparative Studies on Photosynthetic Characteristics of Four Tree Peony Cultivars

The comparative studies on the photosynthetic characteristics of four tree peony cultivars were carried out using the CIRAS-1 photosynthetic instrument in the field light condition.The results showed that the diurnal changes in net photosynthetic rate of the four cultivars presented a double-apex curve.An obvious midday depression phenomenon occurred in tree peony.The photosynthetic rate of Fomenjasha was significantly higher than any other cultivars in the diurnal variation and seasonal variation of photosynthetic rate.Its apparent quantum yield and carboxylation efficiency were the highest.There were no significant difference between four cultivars in light saturation point,but light compensation point of Fomen jiasha was significantly lower than the other cultivars.