Analysis of the interaction effects of light and O3 on fluorescence properties of 'Cabernet Sauvignon' grapes based on response surface methodology

One-year-old potted Vitis vinifera L. cv. Cabernet Sauvignon grapevines were used to analyze the interaction effects of light and O-3 (ozone). Thirteen combinations of different O-3 concentrations and light intensities derived from design expert response surface software were conducted, and the result showed that light and O-3, both individually and together, significantly decreased the F-v/F-m of leaves, providing a regression equation of Y (FvFm ratio) = 0.73 - 0.034*A (O-3 concentration) - 0.022*B (light intensity) - 0.018*A*B - 5.163*10(-3)*A(2) + 8.375*10(-4) *B-2. An F-v/F-m value of 0.711 was used as target for model validation, which was used for the obtained 30 O-3 concentration and light intensity combinations. Values of 1220 mu mol m(-2) s(-1) light intensity + 100 nL/L O-3 and 1400 mu mol m(-2) s(-1) light intensity + 117 nL/L O-3 treatment were selected to validate the model, and the model was validated. This model is constructed as a possible approach to forecast for leaf injury under different O-3 concentrations and light intensity combinations. Using this equation, light intensity that is likely to injure the leaves of Cabernet Sauvignon can be calculated under different O-3 concentrations. According to the Chinese new national standard, 93.46 nL/L O-3 is considered the pollution criterion; thus, the leaves of Cabernet Sauvignon were likely injured at light intensity above 1600 mu mol m(-2) s(-1), suggesting that a protective canopy should be used when light intensity is above this value.