In Vitro Screening of Zea mays L. for drought tolerance

The drought tolerance of two local varieties of Zea mays L. (var. indentata and var. everta) were studied using different concentrations (0 g/l, 3 g/l and 5 g/l) of polyethylene glycol (PEG) in Murashige and Skoog (MS) medium. The maize seeds were surface sterilized with 10% (v/v) sodium hypochlorite for 15 minutes and subsequently in 70% (v/v) ethanol for 1 minute and thereafter rinsed thrice with sterile water. The sterile seeds were inoculated in the growth media and observed for growth. The experiment was done in a completely randomized design (CRD) with ten replicates for a period of 15 days and growth parameters were evaluated. The result showed that for var. indentata, the shoot length (19.15 ± 1.34cm), leaf length (16.62 ± 1.27cm), leaf width (1.19 ± 0.07cm) and leaf number (3.00 ± 0.15cm) of the plants grown in the control medium were significantly higher (P < 0.05) than those grown in media containing 3g/l and 5g/l PEG, but the root number (8.80 ± 1.03cm) was lower in the control compared to the media containing PEG. The same pattern of increase in control compared to media containing PEG were also observed for var. everta. With the growth parameters of the control being the highest for both varieties, it therefore shows that both var. indentata and var. everta are susceptible to drought.