Table 1.
Physiological responses of the two contrasting maize inbred lines to drought stress.
| Physiological Characteristics | Treatment Exposure Period (days) 1 | Sensitive Inbred Line MO17 | Tolerant Inbred Line YE8112 | ||
|---|---|---|---|---|---|
| Control | Stress | Control | Stress | ||
| Leaf relative water content (%) | 1 | 92.23 ± 0.1763 b | 90.33 ± 0.8819 c | 94.63 ± 0.2603 a | 92.53 ± 0.1202 b |
| 3 | 93.03 ± 0.0882 a | 88.53 ± 0.1202 b | 93.70 ± 0.4163 a | 89.90 ± 0.3056 b | |
| 5 | 92.83 ± 0.4910 a | 70.43 ± 0.1202 c | 94.60 ± 0.4042 a | 86.53 ± 0.2848 b | |
| 7 | 92.73 ± 0.2403 a | 65.40 ± 0.2082 c | 93.80 ± 0.3215 a | 81.80 ± 1.0214 b | |
| Proline content (µg·g−1 FW) |
1 | 88.62 ± 0.3358 a | 80.45 ± 0.6265 b | 73.99 ± 0.7420 c | 89.95 ± 0.3259 a |
| 3 | 88.78 ± 0.1981 c | 93.68 ± 0.5860 b | 74.29 ± 1.1873 d | 97.19 ± 1.0451 a | |
| 5 | 88.69 ± 0.5200 c | 99.78 ± 1.3309 b | 75.25 ± 0.6094 d | 108.00 ± 0.9824 a | |
| 7 | 87.67 ± 1.2440 c | 109.21 ± 0.7280 b | 78.07 ± 0.9696 d | 121.96 ± 0.7967 a | |
| Peroxidase activity (unit·mg−1 protein FW min−1) |
1 | 0.2653 ± 0.0028 b | 0.2747 ± 0.0023 b | 0.2590 ± 0.0012 c | 0.3083 ± 0.0035 a |
| 3 | 0.2630 ± 0.0059 c | 0.3147 ± 0.0015 b | 0.2557 ± 0.0008 c | 0.3553 ± 0.0047 a | |
| 5 | 0.2530 ± 0.0064 d | 0.3677 ± 0.0020 b | 0.2643 ± 0.0052 c | 0.3847 ± 0.1186 a | |
| 7 | 0.2563 ± 0.0043 c | 0.4033 ± 0.0039 b | 0.2653 ± 0.0073 c | 0.4350 ± 0.0012 a | |
| MDA content (µmol·g−1 FW) | 1 | 0.0119 ± 0.00003 b | 0.0128 ± 0.00024 a | 0.0118 ± 0.00067 b | 0.0119 ± 0.00006 b |
| 3 | 0.0117 ± 0.00031 c | 0.0152 ± 0.00015 a | 0.0117 ± 0.00018 c | 0.0123 ± 0.00028 b | |
| 5 | 0.0115 ± 0.00012 a | 0.0207 ±0.0002 8 c | 0.0119 ± 0.00023 a | 0.0153 ± 0.00057 b | |
| 7 | 0.0120 ± 0.00012 a | 0.0220 ± 0.00005 c | 0.0118 ± 0.00018 a | 0.0204 ± 0.00036 b | |
| Drought stress injury symptoms | At 7 days | Not visible | Leaves distinctly shriveled up | Not visible | Leaves remain green and relatively intact |
1 Physiological indices were recorded at different time points, viz. 1, 3, 5, and 7 days after drought treatment exposure; FW, fresh weight. Data are presented as mean of three replicates ± standard deviation. Means with similar letter(s) within the same row and for a particular characteristic do not differ significantly at 5% level using least significant difference (LSD) test.