Abstract: 【Objective】In recent years, due to its unique appearance and special nutritional value, colored rice has developed rapidly in the sightseeing agriculture, selection and production of special nutritional rice. However, the mechanism underlying the photosynthetic response of leaves in colored rice to light remains to be elucidated.【Method】In this experiment, four rice varieties with different chlorophyll content in leaves were selected in this experiment, that is deep purple (DP), fale green (FG), dark green (DG) and fale purple (FP). The change characteristics of leaf photosynthesis were studied and response mechanisms were revealed.【Result】The results indicated that the highest chlorophyll content was showed in DP, followed by the DG and FP, while the lowest value were found in FG. Under this case, the FG variety attained the highest value of actual fluorescence quantum efficiency of PSII, photosynthetic rate, ribulose-1, 5-bisphosphate carboxylase activity and total dry matter weight, which was significantly higher than the other varieties. The content of hydrogen peroxide and malondialdehyde in FG leaves was significantly lower than other rice varieties. Besides, there is no significant difference in leaf chlorophyll content and carotenoid content between DP and DG, while the actual fluorescence quantum efficiency of PSII, net photosynthetic rate, ribulose-1,5-diphosphate carboxylase activity in leaves of DP were significantly higher than those of DG. Correspondingly, activities of antioxidant enzymes in leaves of DP were significantly higher than those of DG, while the content of hydrogen peroxide and malondialdehyde were significantly lower than DG. This may be related to the anthocyanin content in the leaves, because the anthocyanin content in the leaves of DP was significantly higher than that of DG. The leaf photosynthetic rate was significantly increased and hydrogen peroxide content was significantly decreased after foliar application of anthocyanin. 【Conclusion】Therefore, it was inferred that anthocyanin might exert important role in alleviating the inhibition effect caused by excess opical quantum on the photosynthesis of leaves under natural conditions. The results could provide a theoretical basis for rice high light efficiency breeding and exploitation for high quality and high efficiency cultivation technology of colored rice.

Key words: colored rice, chlorophyll, photosynthesis, antioxidant capacity, anthocyanin