Figure 1

Figure 2

Figure 3

Plant height, stem diameter and root length of Chinese red under different salinity treatments
| SLev | Salt duration (weeks) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | ||
| Plant height, cm | T1 | 14.9 a | 20.2 b | 30.0 c | 40.0 d | 45.0 e | 53.3 f | 66.0 g | 71.0 h | 82.0 i | 87.6 j | 97.6 k | 110.6 l |
| T2 | 13.9 i | 16.7 k | 22.8 j | 29.2 i | 33.7 h | 38.4 g | 45.6 f | 47.5 e | 56.0 d | 57.1 c | 57.2 b | 57.2 a | |
| T3 | 13.2 c | 18.3 d | 21.8 e | 25.3 f | 35.0 g | 36.4 g | 36.1 g | 36.3 g | 36.1 g | 36.2 g | 36.2 g | 36.1 g | |
| T4 | 8.4 b | 17.3 c | 23.7 d | 28.6 e | 28.7 e | 28.5 e | 28.6 e | 28.3 e | 28.7 e | 28.6 e | 28.6 e | 28.4 e | |
| Stem diameter, cm | T1 | 3.6 a | 3.8 a | 4.4 a | 5.1 ab | 6.8 b | 9.1 bc | 11.6 c | 15.0 d | 17.2 de | 18.9 e | 20.6 e | 21.6 e |
| T2 | 2.6 b | 2.8 b | 3.9 c | 4.3 d | 4.9 e | 5.2 e | 5.8 f | 7.8 g | 9.1 g | 9.2 g | 9.14 g | 9.2 g | |
| T3 | 2.4 c | 2.8 d | 3.5 e | 5.1 f | 7.5 g | 7.5 g | 7.1 g | 7.1 g | 7.2 g | 7.2 g | 7.2 g | 7.2 g | |
| T4 | 1.7 d | 2.2 e | 2.6 f | 2.5 f | 2.2 f | 2.1 f | 2.7 f | 2.6 f | 2.6 f | 2.7 f | 2.6 f | 2.6 f | |
| Root length, cm | T1 | 10.2 a | 11.4 ab | 14.3 b | 18.4 c | 20.4 cd | 23.6 d | 26.1 de | 28.4 e | 30.1 ef | 31.2 ef | 32.3 f | 32.3 f |
| T2 | 9.5 b | 11.7 c | 13.2 d | 15.1 e | 17.2 f | 8.1 f | 20.4 g | 21.6 gh | 22.9 h | 23.6 h | 23.7 h | 23.7 h | |
| T3 | 8.9 c | 10.6 d | 14.7 e | 15.4 f | 18.8 g | 18.7 g | 18.6 g | 18.6 g | 18.6 g | 18.5 g | 18.5 g | 18.6 g | |
| T4 | 8.5 d | 9.1 e | 10.5 f | 11.3 k | 11.3 k | 11.3 k | 11.6 k | 11.3 k | 11.1 k | 11.3 k | 11.2 k | 11.3 k | |
Variance analysis of growth traits of two okra cultivars under salt stress
| Main variables | Cult | SLev | SDur | Cult × SLev | Cult × SDur | SLev × SDur | Cult × SLev × SDur |
|---|---|---|---|---|---|---|---|
| PH | 87.227** | 16630.85** | 4912.286** | 8.318** | 18.801** | 1008.619** | 18.078** |
| RL | 94.138** | 6422.472** | 1603.98** | 258.563** | 10.662** | 300.922** | 13.369** |
| SD | 1.822NS | 3940.037** | 655.581** | 64.922** | 0.294NS | 206.851** | 2.058** |
| FW | 34.992** | 4948.99** | 662.663** | 40.121** | 4.575** | 208.645** | 7.73** |
| DW | 13.041** | 1916.822** | 249.977** | 5.433** | 1.289NS | 75.574** | 0.874NS |
Correlation between different parameters of two okra cultivars
| SD | RL | FW | DW | PN | Gs | E | WUE | Wp | SDur | SLev | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Green | |||||||||||
| PH | 0.952** | 0.969** | 0.950** | 0.934** | 0.693** | 0.549** | 0.350** | 0.544** | 0.392** | 0.593** | –0.578** |
| SD | 0.978** | 0.982** | 0.956** | 0.768** | 0.667** | 0.368** | 0.605** | 0.496** | 0.497** | –0.640** | |
| RL | 0.976** | 0.957** | 0.726** | 0.589** | 0.350** | 0.580** | 0.425** | 0.571** | –0.601** | ||
| FW | 0.986** | 0.808** | 0.683** | 0.394** | 0.646** | 0.508** | 0.481** | –0.663** | |||
| DW | 0.803** | 0.675** | 0.398** | 0.637** | 0.509** | 0.472** | –0.660** | ||||
| PN | 0.932** | 0.154 | 0.907** | 0.839** | 0.017 | –0.840** | |||||
| Gs | 0.154 | 0.818** | 0.891** | –0.115 | –0.845** | ||||||
| E | –0.170* | 0.024 | 0.393** | –0.296** | |||||||
| WUE | 0.800** | –0.115 | –0.758** | ||||||||
| Wp | –0.324** | –0.859** | |||||||||
| SDur | 0.000 | ||||||||||
| Red | |||||||||||
| PH | 0.957** | 0.946** | 0.961** | 0.951** | 0.665** | 0.460** | 0.428** | 0.505** | 0.302** | 0.642** | –0.572** |
| SD | 0.947** | 0.967** | 0.967** | 0.679** | 0.523** | 0.450** | 0.521** | 0.410** | 0.544** | –0.623** | |
| RL | 0.940** | 0.943** | 0.666** | 0.440** | 0.510** | 0.509** | 0.343** | 0.604** | –0.644** | ||
| FW | 0.992** | 0.796** | 0.621** | 0.413** | 0.635** | 0.483** | 0.479** | –0.680** | |||
| DW | 0.797** | 0.620** | 0.418** | 0.642** | 0.496** | 0.469** | –0.694** | ||||
| PN | 0.894** | 0.212* | 0.912** | 0.811** | 0.000 | –0.857** | |||||
| Gs | 0.187* | 0.813** | 0.893** | –0.221** | –0.853** | ||||||
| E | –0.130 | 0.074 | 0.465** | –0.387** | |||||||
| WUE | 0.789** | –0.141 | –0.766** | ||||||||
| Wp | –0.381** | –0.817** | |||||||||
| SDur | 0.000 | ||||||||||
Different treatment levels
| Treatment | Concentration (mM) | Amount of NaCl in 1 L Hoagland culture medium (g · L−1) | Amount of CaCl2 in 1 L Hoagland culture medium (g · L−1) |
|---|---|---|---|
| T1 | 20.8 | 0 | 0 |
| T2 | 103.3 | 3 | 3 |
| T3 | 180.0 | 6 | 6 |
| T4 | 257.0 | 9 | 9 |
Variance analysis of physiological traits of two Okra cultivars under salt stress treatments
| Main variables | Cult | SLev | SDur | Cult × SLev | Cult × SDur | SLev × SDur | Cult × SLev × SDur |
|---|---|---|---|---|---|---|---|
| PN | 33.72** | 7382.7** | 72.59** | 63.58** | 1.49NS | 118.81** | 2.17** |
| Gs | 14.60** | 2249.22** | 20.03** | 6.81** | 2.35** | 12.75** | 2.92** |
| E | 92.59** | 77.75** | 19.10** | 13.08** | 3.51** | 7.42** | 4.51** |
| WUE | 54.83** | 646.96** | 15.71** | 2.45NS | 2.98** | 21.35** | 3.32** |
| Wp | 46.30** | 1332.00** | 71.77** | 18.81** | 1.52NS | 12.43** | 1.24NS |
Plant height, stem diameter and root length of Chinese green under different salinity treatments
| SLev | Salt duration (weeks) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | ||
| Plant height, cm | T1 | 14.2 a | 23.8 b | 30.4 c | 36.3 d | 43.7 e | 49.9 f | 57.3 g | 64.2 h | 76.7 i | 83.5 j | 103.0 k | 117.6 l |
| T2 | 13.1 f | 18.1 h | 21.9 c | 31.3 g | 35.6 e | 44.9 f | 48.0 f | 52.2 g | 52.4 g | 52.14 g | 52.4 g | 52.3 g | |
| T3 | 12.3 a | 17.8 b | 23.8 f | 27.8 d | 32.6 e | 32.4 e | 32.6 e | 32.3 e | 32.5 e | 32.5 e | 32.4 e | 32.6 e | |
| T4 | 11.9 a | 18.9 c | 26.4 b | 26.5 b | 26.5 b | 26.5 b | 26.5 b | 26.5 b | 26.3 b | 26.4 b | 26.3 b | 26.4 b | |
| Stem diameter, cm | T1 | 3.6 a | 4.1 a | 4.4 ab | 5.4 ab | 7.8 bc | 10.7 bc | 13.6 cd | 16.9 d | 19.7 d | 21.3 e | 22.1 e | 23.0 e |
| T2 | 2.4 b | 2.8 c | 3.8 a | 4.4 d | 5.13 e | 5.3 f | 5.9 g | 8.3 g | 8.5 g | 8.5 g | 8.51 g | 9.0 g | |
| T3 | 2.2 d | 2.8 b | 3.7 b | 3.8 a | 5.6 g | 5.7 g | 5.6 g | 5.8 g | 5.6 g | 5.4 g | 5.6 g | 5.6 g | |
| T4 | 1.9 e | 2.4 f | 2.8 g | 3.1 h | 3.1 h | 3.1 h | 3.1 h | 3.1 h | 3.2 h | 3.1 h | 3.08 h | 3.1 h | |
| Root length, cm | T1 | 9.8 a | 12.0 b | 14.1 c | 15.2 d | 17.5 e | 20.4 f | 25.9 g | 29.9 h | 33.1 i | 33.6 ij | 34.1 j | 35.1 k |
| T2 | 9.6 a | 9.8 bc | 10.8 b | 13.4 e | 14.9 d | 17.3 g | 19.3 f | 20.8 j | 20.6 j | 20.7 j | 20.8 j | 20.7 j | |
| T3 | 9.7 c | 11.7 a | 12.7 d | 13.4 b | 14.2 h | 15.2 i | 15.3 i | 15.3 i | 15.3 i | 15.3 i | 15.2 i | 15.3 i | |
| T4 | 9.4 d | 11.2 c | 12.1 b | 12.5 b | 12.6 b | 12.7 b | 12.6 b | 12.6 b | 12.6 b | 12.6 b | 12.6 b | 12.3 b | |