A coupled model of stomatal conductance and photosynthesis for winter wheat

Abstract

The model couples stomatal conductance (g s ) and net photosynthetic rate (P N ) describing not only part of the curve up to and including saturation irradiance (I max ), but also the range above the saturation irradiance. Maximum stomatal conductance (g smax ) and I max can be calculated by the coupled model. For winter wheat (Triticum aestivum) the fitted results showed that maximum P N (P max ) at 600 μmol mol −1 was more than at 350 μmol mol −1 under the same leaf temperature, which can not be explained by the stomatal closure at high CO 2 concentration because g smax at 600 μmol mol −1 was less than at 350 μmol mol −1 . The irradiance-response curves for winter wheat had similar tendency, e.g. at 25 o C and 350 μmol mol −1 both P N and g s almost synchronously reached the maximum values at about 1 600 μmol m -2 s −1 . At 25 o C and 600 μmol mol −1 the I max corresponding to P max and g smax was 2 080 and 1 575 μmol m -2 s −1 , respectively.Additional key words: BWB model; irradiance; Triticum. --In the simulation of stomatal conductance (g s ), an empirical model for plant leaves by Ball et al. (1987), hereafter referred to as the BWB model, has been adopted widely in studies of ecological and physiological modelling. It has a solid experimental basis with a linear relationship between g s and net photosynthetic rate, P N (e.g. Ball et al. 1987, Di Marco et al. 1990

Shading tolerance in rice is related to better light harvesting and use efficiency and grain filling rate during grain filling period

“…It took about 30 min to obtain the measurement from one sample and a single replication was used for each flag leaf. The P max (maximum net photosynthetic rate), LSP (light saturation point), LCP (light compensation point), and AQE (apparent quantum yield) were simulated using a modified rectangular hyperbola with Photosynthesis Work Bench (Ye and Yu, 2008). All samples were measured from 09:00 to 12:30 on a clear and cloud less day as stated in the instructions.…”

Gas exchange and Triticum sp. with different ploidy in relation to irradiance

“…Our results show that P n at saturation irradiance in the case of hexaploid T. aestivum (31.1-33.9 µmol CO 2 /m 2 /s) reached comparable values of the tetraploid T. durum (30.0-32.8 µmol CO 2 /m 2 /s). Ye and Yu (2008) state for T. aestivum the value of P max 22.8 µmol CO 2 /m 2 /s (at 25°C and concentration of CO 2 350 μmol/mol). The photoinhibiting effect of light irradiance that would result in the decrease of P n was not recorded in any of the monitored species in case of higher values of irradiance.…”

“…Many studies focus on the mutual relationship between P n and g s (Farquhar andSharkey 1982, Jarvis andDavies 1998) and the modelling of the course of this dependency (Yu et al 2004, Ye andYu 2008). As stated by Li et al (2008), there is a close dependency between P n and g s .…”

Research on Light Response Curve Fitting Model of Four Chamaenerion Plants on the Serzilla Mountains

“…The modified model of rectangular hyperbola [23] [24] for the plant photosynthesis to the light response is expressed as follows:…”