Table 5.
Parameters for the logistic function fitted for each of the three leaf gas exchange variables in response to salinity as indicated in equation 2.
| Genotype | Net photosynthesis rate |
Transpiration rate |
Conductance |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ymax (μmol CO2 m−2 s−1) |
B | A | R2 | RMSEn (%) | Ymax (mmol H2o m−2 s−1) |
B | a | R2 | RMSEn (%) | Ymax (g H2o m−2 s−1) |
b | a | R2 | RMSEn (%) | |
| BRRI Dhan47 | 25.46 ± 1.08 | 16.15 ± 0.4 | 0.19 ± 0.0 | 0.88 | 11.8–9.2 | 6.41 ± 0.24 | 14.30 ± 0.3 | 0.21 ± 0.0 | 0.72 | 17.9–27.6 | 0.47 ± 0.03 | 11.68 ± 0.6 | 0.34 ± 0.1 | 0.92 | 15.5–8.6 |
| IR64 | 19.47 ± 0.9 | 12.39 ± 1.3 | 0.26 ± 0.1 | 0.61 | 23.7–17.5 | 7.08 ± 0.43 | 10.09 ± 0.7 | 0.21 ± 0.0 | 0.54 | 20.0–11.1 | 0.47 ± 0.04 | 8.92 ± 0.3 | 0.26 ± 0.0 | 0.72 | 24.6–17.6 |
| IR29 | 20.61 ± 0.89 | 11.08 ± 1.4 | 0.31 ± 0.1 | 0.59 | 19.9–31.9 | 8.52 ± 0.42 | 6.83 ± 0.2 | 0.31 ± 0.1 | 0.38 | 32.1–3.8 | 0.63 ± 0.03 | 6.77 ± 0.5 | 0.32 ± 0.0 | 0.41 | 23.2–7.9 |
Ymax, maximum value for the rate of the process under control conditions; b, level of salinity at 50% reduction (dS m−1); a is the slope of the linear regression at 50% reduction; R2, coefficient of correlation; RMSEn, normalized root mean square error between the observed and calculated values from the greenhouse experiments (Experiments 1, 2 and 3) and field experiment (Experiment 4). Fitted data were obtained from 4 to 6 plants in each experiment (1–4) for each genotype and each Treatment (control, 1, 2 and 3) measured at three times (7, 14 and 21 d after start of the salinity treatment). Values are means ± se.