Table 2. Effects of different melatonin treatments on various morphological indicators and photosynthetic pigments in maize seedlings under drought stress.
| Melatonin treatmentsa | Stem diameter (mm) | Plant height (cm) | RWC (%) | Leaf area (cm2 plant−1) | Chlorophyll a (mg g−1 FW) | Chlorophyll b (mg g−1 FW) | Carotenoid (mg g−1 FW) | |
|---|---|---|---|---|---|---|---|---|
| Foliar Spray | FCK1 | 9.51 ± 0.21a | 63.5 ± 0.74a | 94.2 ± 3.08a | 486.3 ± 6.83a | 2.92 ± 0.21ab | 0.68 ± 0.03a | 0.35 ± 0.02c |
| FCK2 | 4.97 ± 0.61e | 42.5 ± 1.67e | 71.0 ± 1.21e | 341.4 ± 8.20d | 1.09 ± 0.09d | 0.29 ± 0.02e | 0.23 ± 0.01e | |
| FM1 | 6.05 ± 0.12d | 49.0 ± 1.85d | 77.6 ± 3.20d | 383.6 ± 6.62c | 1.37 ± 0.12d | 0.30 ± 0.01e | 0.28 ± 0.02d | |
| FM2 | 7.07 ± 0.36c | 55.1 ± 2.18c | 83.6 ± 1.62c | 407.3 ± 6.68b | 1.93 ± 0.13c | 0.38 ± 0.01d | 0.29 ± 0.01d | |
| FM3 | 8.02 ± 0.51b | 58.3 ± 1.87b | 86.7 ± 1.81bc | 432.1 ± 6.75b | 2.65 ± 0.34b | 0.47 ± 0.06c | 0.38 ± 0.02b | |
| FM4 | 8.51 ± 0.81b | 58.8 ± 2.92b | 89.7 ± 1.07b | 445.5 ± 4.44b | 3.02 ± 0.37a | 0.61 ± 0.03b | 0.42 ± 0.01a | |
| Soil Drench | DCK1 | 9.00 ± 0.16a | 64.1 ± 1.01a | 91.0 ± 1.29a | 502.5 ± 6.81a | 3.08 ± 0.16a | 0.63 ± 0.03a | 0.37 ± 0.01b |
| DCK2 | 5.16 ± 0.41d | 43.6 ± 1.25e | 68.3 ± 1.69e | 329.4 ± 10.26e | 1.24 ± 0.22c | 0.31 ± 0.04d | 0.25 ± 0.01d | |
| DM1 | 6.68 ± 0.72c | 53.8 ± 1.94d | 78.6 ± 1.95d | 373.2 ± 8.19d | 2.23 ± 0.36b | 0.40 ± 0.02c | 0.31 ± 0.01c | |
| DM2 | 8.95 ± 0.33a | 61.1 ± 1.98b | 85.8 ± 1.05b | 440.1 ± 9.94c | 2.91 ± 0.15a | 0.57 ± 0.06ab | 0.37 ± 0.02b | |
| DM3 | 8.74 ± 0.26a | 59.4 ± 1.16bc | 84.6 ± 1.75bc | 466.3 ± 9.69b | 2.56 ± 0.45ab | 0.55 ± 0.05b | 0.41 ± 0.01a | |
| DM4 | 7.94 ± 0.13b | 57.1 ± 0.53c | 82.6 ± 1.37c | 379.7 ± 8.19d | 2.28 ± 0.41b | 0.56 ± 0.04b | 0.43 ± 0.02a | |
Notes.
a
For Foliar application, FCK1 indicate well-watered, FCK2, drought stress; FM1, FM2, FM3, and FM4 indicates melatonin application at the rate of 25, 50, 75, 100 M, respectively. For soil drench application, DCK1 indicates well-watered, DCK2, drought stress; DM1, DM2, DM3, and DM4 indicates melatonin application at the rate of 25, 50, 75, 100 M. Data are shown as the mean ± S.D. (n = 3). Different letters in the same column indicate a significant difference in particular series at P < 0.05 as determined by the LSD test.