TABLE 3.
Fitted (Eq. 4) and measured (Obs.) values of parameters defining the light response curve of stomatal conductance for C3 (soybean) and C4 species (grain amaranth).
| Species | α0 | gs–max (mol m–2 s–1) | Ig–sat (μmol m–2 s–1) | β0 (m2 s μmol–1) | γ0 (m2 s μmol–1) | gs0 (mol m–2 s–1) | ||||||
| Eq. 4 | Obs. | Eq. 4 | Obs. | Eq. 4 | Obs. | Eq. 4 | Obs. | Eq. 4 | Obs. | Eq. 4 | Obs. | |
| Soybean | (3.5 ± 0.9) × 10–4a | – | 0.26 ± 0.01 | 0.26 ± 0.02 | 2291.90 ± 259.17 | 1800.00 ± 81.65 | (1.7 ± 0.7) × 10–4 | – | (8.6 ± 5.5) × 10–4 | – | 0.06 ± 0.01a | 0.07 ± 0.01a |
| Grain amaranth | (7.3 ± 3.0) × 10–4a | – | – | – | – | – | (-5.6 ± 6.1) × 10–4 | – | (6.1 ± 5.5) × 10–3 | – | 0.09 ± 0.01a | 0.11 ± 0.02a |
The parameters are initial slope of the gs–I curve (α0), coefficients β0 and γ0, the maximum stomatal conductance (gs–max) and the corresponding saturation irradiance (Ig–sat), and the residual stomatal conductance (gs0). All values are the means ± SE (n = 4). Different letters denote statistically significant differences (P ≤ 0.05) between soybean and grain amaranth within each column of fitted (Eq. 4) or measured (Obs.) values. There is no statistically significant difference between fitted (Eq. 4) and measured (Obs.) values for each parameter. See Table 1 for definitions of abbreviations.