Effects of LED light quality on the photosynthetic properties and physiological indexes of‘Summer black'grape

Abstract: 【Objectives】The objective of the study is to elucidate the effects of the different LED light quality on the photosynthetic properties and physiological indexes of grape under shading condition.【Methods】The experimental materials were the grafted‘Summer black'grape which were treated by different LED light quality. Photosynthetic and physiological indexes of grape leaves,such as the photosynthetic rate(Pn),stomatal conductance (G_s),intercellular CO₂ concentration (C_i),transpiration rate(Tr),photosynthetic pigment and enzyme active,were measured and analyzed.【Results】The results showed that the different LED light quality significantly improved the photosynthetic rate(P_n), stomatal conductance(Gs),intercellular CO₂ concentration(Ci)and transpiration rate (T_r) of‘Summer black'grape,compared with the control(CK),which were conducive to the accumulation of photosynthate in leaves. Red light R630 increased the content of chlorophyll. Blue light improved SOD enzyme activity,and red light enhanced POD enzyme activity; Red and blue light RRB440 resulted in the highest content of MDA.【Conclusion】Light quality played important role in promoting growth of‘Summer black'grape.:Summer blackgrapeLED light qualityPhotosynthetic propertiesPhysiological indexes