Table 4.
Model equation in terms of actual factors for measured indices and optimized levels of each factor needed to achieve maximum or minimum Response
| Trait | Model | Model equation in terms of actual factors | Optimized levels of factors (Salinity stress and GABA) | Targeted response | Optimized response |
|---|---|---|---|---|---|
| Piperitenone oxide content | Reduced cubic | R = 74.73 -0.36 × 1-1.9 × 2 -0.24 × 1 × 2-0.003 × 12 + 0.0017 × 12 × 2 | 95 mM and 0.2 mM | Maximum | 81% |
| Essential oil content | Reduced quadratic | R = 0.17 + 0.008 × 1 + 0.030 × 2-0.0008 × 1 × 2-0.0003 × 2 | 100 mM and 0.1 mM | Maximum | 0.6% |
| Shoot dry weight | Linear | R = 27.26-0.10 × 1 + 1.85 × 2 | 0 mM and 2.4 mM | Maximum | 32 g |
| Root dry weight | Linear | R = 13.81-0.06 × 1 + 0.36 × 2 | 0 mM and 2.4 mM | Maximum | 15 g |
| Total phenols content | Reduced quartic | R = 124.50-4.01 × 1-258.02 × 2 + 16.53 × 1 × 2 + 0.02 × 12 + 110.80 × 22-0.11 × 12 × 2 -6.98 × 1 × 22 + 0.046 × 12 × 22 | 75 mM and 1.2 mM | Maximum | 191 mg GAE g− 1 DW |
| Total flavonoids content | Reduced quartic |
R = 26.51-0.78 × 1-38.47 × 2 + 2.28 × 1 × 2+ 0.005 × 12 + 17.58 × 22-0.012 × 12 × 2-0.93 × 1 × 22 + 0.005 × 12 × 22 |
112 mM and 1.1 mM | Maximum | 48 mg QE g-1 DW |
|
DPPH-scavenging Activity |
Reduced quartic | R = 31.06-3.32 × 1 -128.77 × 2 + 8.40 × 1 × 2 + 0.023 × 12 + 53.27 × 22 -0.049 × 12 × 2 -3.18 × 1 × 22 + 0.018 × 12 × 22 | 116 mM and 1.30 mM | Maximum | 80% |
| Relative water content (%) | Reduced cubic | R = 88.64 + 0.11 × 1 -17.75 × 2 -0.025 × 1 × 2-0.0017 × 12 + 5.261 × 22 + 0.035 × 1 × 12 | 75 mM and 2.4 mM | Maximum | 86% |
|
Proline content (mg g− 1 FW) |
Reduced quartic | R = 6.65 + 0.051 × 1 -25.63 × 2 + 0.56 × 1 × 2 -0.0036 × 12 + 10.81 × 22 -0.0035 × 12 × 2 -0.24 × 1 × 22 + 0.0015 × 12 × 22 | 115 mM and 1.7 mM | Minimum | 3.35 mg g− 1 FW |
|
MDA content (mg g− 1 FW) |
Reduced cubic | R = 11.22-0.06 × 1 + 0.51 × 2 + 0.029 × 1 × 2 + 0.001 × 12-0.0005 × 12 × 2 | 150 mM and 2.4 mM | Minimum | 6.35 mg g− 1 FW |
|
Chlorophyll a content (mg g− 1 FW) |
Quadratic | R = 4.08-0.022 × 1-2.19 × 2 + 0.0075 × 1 × 2 + 0.00026 × 12-0.861 × 22 | 70 mM and 2.4 mM | Maximum | 5.3 mg g− 1 FW |
|
Chlorophyll b content (mg g− 1 FW) |
Reduced cubic | R = 1.4 + 0.029 × 1-2.20 × 2 + 0.0009 × 1 × 2-0.0002 × 12 + 0.97 × 22 + 0.00006 × 12 × 2 -0.004 × 1 × 22 | 70 mM and 0.25 mM | Maximum | 1.93 mg g− 1 FW |
|
Carotenoids content (mg g− 1 FW) |
Linear | R = 0.296-0.001 × 1 + 0.022 × 2 | 0 mM and 2.4 mM | Maximum | 0.35 mg g− 1 FW |
| Fv/Fm ratio | Quadratic | R = 0.76-0.0004 × 1 + 0.030 × 2 + 0.00029 × 1 × 2-0.50 × 12-0.011 × 22 | 0 mM and 1.3 mM | Maximum | 0.79 |