This study was conducted to evaluate the physiological response of 20 maize varieties belonging to two different maturity groups under drought at seedling stage and normal growth conditions. The screenhouse experiment was laid out using randomized complete block design with three replications. Data were recorded on seedling aspect, proline and chlorophyll contents and subjected to analysis of variance to establish significant difference. Results revealed that drought stress significantly (p≤.05) reduced chlorophyll a, b and total chlorophyll contents. Proline and seedling aspect of both early and late maturing varieties under drought stress were significantly (p≤.05) higher compared to those that were not stressed. Furthermore, proline produced by early-maturing maize was slightly higher (0.61 µmol L-1) than that of late-maturing maize (0.56 µmol L-1), signifying that early-maturing maize might be more susceptible to drought at seedling stage. Similarly, seedling aspect in early-maturing maize varieties was higher (6.65) than that of late-maturing maize varieties (5.93), indicating that the early-maturing maize are more sensitive to moisture stress than the late maturing varieties.
In conclusion, seedling aspect and proline accumulation are important indicators of tolerance to drought at seedling stage for both classes of maize. Early-maturing varieties were more susceptible than the late maturing maize.
Keywords: chlorophyll content, proline content, seedling aspect, Zea mays.