Table 1. Three comparisons of parameter values and sum of squared residuals (SSR) . Rice reps are the replicates from Xiao et al. (2021) showing the differences that occur when the triose phosphate utilization (TPU) limitation is considered and when it is not (fittings of the data in Figure 1 A-D). J will always be underestimated when TPU limited points are treated as being J -limited. Without the TPU limitation, our fitting program was unable to resolvegm and so the arbitrary limit of 100 is shown. The last two columns show the effect of measuring theA /Ci relationship by the split method versus monotonically (low to high CO2 in this case usingNicotiana tabacum, fittings of the curves shown in Figure 1 D and E). Although no discontinuity was apparent, the SSR was lower in the monotonic case. Multiple trials were made and SSR was always smaller when the curves measured monotonically rather than by the split method.
Figure 1. Fitting A/Ci curves. A and B fits to rice data (replication 2 of Xiao et al. 2021) without (A) or with (B) TPU, C and D are fits to replication 3. The effect of split A/Ci determination (E) or monotonic (increasing CO2) (F) for Nicotiana tabacum . Red is the fitted shape for rubisco-limited condition, blue is for the RuBP regeneration-limited condition and gold is for the TPU-limited condition.
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