Effects of the red:far-red light ratio on photosynthetic characteristics of greenhouse cut Chrysanthemum – Short communication
Z.Q. Yang, Y.X Li, J.B. Zhang, J. Zhang, J. Zhu, L.L. Gu, B. Zhanghttps://doi.org/10.17221/43/2012-HORTSCICitation:Yang Z.Q., Li Y.X., Zhang J.B., Zhang J., Zhu J., Gu L.L., Zhang B. (2013): Effects of the red:far-red light ratio on photosynthetic characteristics of greenhouse cut Chrysanthemum – Short communication. Hort. Sci. (Prague), 40: 40-43.
For the use of LED as a light source to regulate the photosynthesis of chrysanthemum leaves under greenhouse conditions, the effects of different red (660 ± 30 nm) to far-red (730 ± 30 nm) radiation ratios (R:FR) on the photosynthetic characteristics and chlorophyll fluorescence parameters of chrysanthemum leaves were studied. Red and far-red LED light sources were combined in different proportions to produce four R:FR ratio treatments: 0.5, 2.5, 4.5 and 6.5. The chlorophyll a content, SPAD value, net photosynthetic rate, light-saturated maximum photosynthetic rate, CO2-saturated carboxylation rate, apparent quantum efficiency and carboxylation efficiency were all the highest under the R:FR ratio of 2.5, followed by the R:FR ratio of 4.5. Potential photochemical efficiency of photosystem II, photochemical quenching and electron transport rate for the R:FR ratios of 2.5 and 4.5 were markedly higher than those for 0.5 and 6.5, however, those parameters did not differ significantly between the R:FR ratios of 2.5 and 4.5.Keywords:
chrysanthemum; R:FR; LED; photosynthesis; chlorophyll fluorescence