Abstrait

Seasonal changes of photosynthetic physiology in Jatropha curcas L. from autumn to winter

Ke Chen, Juanyu Jiao, Jing Zhu

Jatropha curcas L. seedling were pot-planted and grown under natural conditions. Our study was to monitor changes in the composition of the photosynthetic apparatus which accompany these functional changes, and to determine their adaptability to the climatic conditions. Seasonal changes in chlorophyll fluorescence, gas exchanges, rapid light responses curves in chlorophyll fluorescence, pigment concentration and antioxidase in J. curcas were examined from autumn to cold winter climate. The results revealed that there were significantly decreased in total parameters except Intercellular CO2 concentration through fall and winter. But J. curcas remained able to have photosynthesis before the leaves fallen. During December, net photosynthetic rate (Pn) and maximum quantum efficiency of PSII (Fv/Fm) were significantly down-regulated. It is conclusion that the high degree of photoinhibition observed in J. curcas L. leaves probably represents a dynamic regulatory process protecting the photosynthetic apparatus from severe damage by excess light and low temperature