Light-response curve of photosynthesis and model fitting in leavesof Mangifera indica under different soil water conditions

Abstract

A pot experiment was performed to study the light-response curve of photosynthesis (PN-PAR curve) of Mangifera indica and the applicability of light-response models under different soil water conditions. The experimental data were fitted and analyzed using the rectangular hyperbola model, the nonrectangular hyperbola model, the exponential model, the modified rectangular hyperbola model, and the kinetic model. The results showed that the optimal range of relative soil water content (RSWC) for the normal photosynthesis of M. indica was 45.1-77.3%. The modified rectangular hyperbola model could well fit the PN-PAR curves and photosynthetic parameters under wide range of soil water conditions (RSWC 23.3-77.3%). The rectangular hyperbola model, the nonrectangular hyperbola model, the exponential model, and the kinetic model could only be used to fit the PN-PAR curves of M. indica under mild and moderate drought stress (RSWC 45.1-77.3%).

Leaf photosynthetic light response of summer maize: comparison of models and analysis of parameters

“…Soil drought would suppress photosynthesis in plants to some extent, thus affecting PNmax. It was found that PNmax significantly decreased with the decrease of soil water content (Xu et al 2013, Li et al 2019. In this study, SWC ranged between 39-61% of the field capacity.…”

“…Many studies showed that the Ye model had a greater simulation effect compared to other four light-response models (Ye 2007, Zheng et al 2012, Lang et al 2013, Ren et al 2017, while the fitting capacity of RH model was the worst (Li et al 2019). AQY obtained by RH model was often higher than the measured value (Gomes et al 2006, Ye 2007, Xia et al 2014.…”

“…The result was the same in this study (Table 2). PNmax represents the maximum photosynthetic capacity of leaves, thus determining photosynthetic rate at high light intensity (Li et al 2019). Is is the light intensity when photosynthetic rate reaches its maximum.…”

“…The measurement and simulation of photosynthetic lightresponse curve is an important and useful tool for understanding the photosynthesis and ecology of plants, which is the basis for revealing the response of the photosynthetic process to environment (Li et al 2019). The main physiological parameters, including maximum net photosynthetic rate (PNmax), apparent quantum yield (AQY), light-saturation point (Is), light-compensation point (Ic), and dark respiration rate (RD), can be obtained from the curve and thus determine the operation state of plant photosynthetic apparatus, photosynthetic capacity, and photosynthetic efficiency, as well as environmental changes influencing them Yu 2008a, Xia et al 2014).…”

“…Based on the Ye model, Is and Ic of Quercus variabilis Blume significantly increased with the increase of Ta; PNmax and Is had significantly positive relationship with stomatal conductance (gs) and relative humidity (rh), respectively (Ren et al 2017). When soil water content (SWC) was within the optimal range, PNmax simulated by the Ye model increased with the increase in SWC (Ge et al 2012, Lang et al 2013, Xia et al 2014, Li et al 2019.…”