Water Stress Induced by Polyethylene Glycol 6000 and Sodium Chloride in Two Maize Cultivars

Responses of growth and germination to water stress induced by PEG 6000 and NaCl in two maize (Zea mays L.) cultivars 704 and 301 were studied. Water stress was generated by additions of PEG 6000 or sodium chloride to the root medium. Water potentials were: zero as control and -0.15, -0.49, -1.03 and -1.76 MPa as treatments. After 24 h treatment, the roots and shoots length and dry weight were of plants determined. In water stress, roots and shoots length and dry weight decreased at both treatments in both varieties. The germination is inversely proportional to the NaCl and PEG concentrations, it means that 704 and 301 cultivars of maize showed a reduction in germination with an increasing in NaCl or PEG concentrations induced water deficit, but this reduction in NaCl treatment were higher than PEG treatment. At treatment by PEG, the germination was severely decreased at -1.03 MPa. At treatment by NaCl no germination occurred at -1.03 in 301 var. and germination was very low at -1.03 MPa in 704 var., no germination occurred at -1.76 MPa in both varieties at both treatments. Decrease of germination in 704 variety was higher than 301 variety.