Abstract: The effects of different light qualities generated by light emitting diodes (LED) on the photosynthetic characteristics of Curcuma longa L. were studied. The results showed that red light, blue light, and combined red + blue light all increased the curcumin content. In addition, red light increased the contents of chlorophyll a, total chlorophyll and soluble sugar. The blue light benefited the contents of caroteoids and protein, the activities of superoxide dismutase (SOD) and peroxidase (POD). The green light improved the contents of caroteoids and protein, while yellow light promoted the accumulation of protein. The chlorophyll and carotenoid concentrations, SOD activities and the ratio of F_vF_o significantly increased by 14.23%, 23.60%, 18.18%, 22.60% and 66.65% respectively under the red/blue light=7:3 treatment, suggesting that the ratio of 7:3 was optimum for the growth and curcumin accumulation of C. longa.

Key words: pollution effects, Tangshan Bay., zooplankton, driving factors, community structure