Abstract:

Diurnal change of net photosynthetic rate and light response, CO2 response of two Guzmania varieties ‘Guzmania ‘Rana’’ and ‘Guzmania Denise’ were studied using LI-6400 Portable Photosynthesis System. The results showed that the diurnal change of net photosynthetic rate presented a double peak curve with Rana higher than Denise. The “midday depression” of Guzmania could be attributed to the high temperature and radiation, which caused the partly closure of stomato and inhibition of photosynthesis. Denise had higher light saturation point and light compensation point than Rana, however its apparent quantum efficiency and dark respiration rate were lower. The CO2 compensation point of Rana was close to that of Denise, while its CO2 saturation point was higher than Denise’s. The net photosynthetic rate of Rana at CO2 saturation point was higher than that of Denise significantly, whereas they had the same carboxylation efficiency. Finally a few of suggestions were put forward for arranging the commercial production based on the results of this research.