Abstract:

Effects of light quality on the growth, photosynthesis and chlorophyll fluorescence of ginger were investigated in this study. The results indicated that white or red light induced the greatest growth, chlorophyll content and net photosynthetic rate (Pn), followed by blue and green light in order from high to low level. When ginger seedlings were transferred to sunlight, the Pn and photorespiration (Pr) of leaves treated with white light were the highest, followed by blue, red or green light in turn, while that of Pr/Pn was reverse. The maximal photochemical efficiency (Fv/Fm) and efficiency of excitation energy capture by open PSⅡ reaction centres (Fv′/Fm′) as well as photochemical quenching coefficient (qP) decreased markedly under middy strong light. But their values in different treatments were different, with the highest values in white light treatment, followed by blue, red or green light in order from high to low level. Contrarily, white, blue, red or green light treatment induced the relative deviation from full balance between two photosystems (β/α-1) in ginger leaves increased in turn. In parallel, the excitation energy used in photochemical reaction (P) of leaves treated with white light was the highest, the next was blue or red light, and the lowest was green light. While the antenna heat dissipation (D) and excess light energy (E) of PSⅡ in ginger leaves treated with green light was the highest and white light was the lowest.

Key words: ginger, light quality, growth, photosynthetic rate, chlorophyll fluorescence