Salinity Stress Effect on the Germination of Three Cereals: Maize (Zea mays), Millet (Pennisetum glaucum) and Rice (Oriza sativa)

Abstract

In Africa, cereals are major staple foods for the majority of the population. The cereal crop is not immune to the problem of salinity, which could threaten 10% of its world harvest. This work was undertaken to study the comparative effect of salinity on germination of three cereals, maize (Zea mays), millet (Pennisetum glaucum) and rice (Oriza sativa). The seeds were germinated in Petri dishes containing a range of NaCl solution (0 g/l, 5 g/l, 10 g/l, 15 g/l and 25 g/l) in the dark and at room temperature. The harmful effect of salt varies depending on the concentration of NaCl and the type of cereal. It is low on the germination rate of seeds up to a concentration of 10 g/l NaCl. From this dose onwards, this rate is reduced by 44% for millet, 20% for rice and 10% for maize. The average germination time between 0 g/l and 10 g/l NaCl is low and increases strongly between 10 g/l and 15 g/l and reaches 37 days (millet) and 20 days (rice). Corn root growth is less affected by salinity (1.2 cm) at 15 g/l NaCl compared to more sensitive rice and millet (0 cm). The height of the epicotyl between 0 g/l and 25 g/l NaCl increased from 11.8 to 3.6 cm (corn), from 0.5 to 0 cm (rice) and from 4.3 to 0.3 cm (millet). The combination of the parameters studied shows that all three cereals are able to tolerate NaCl concentrations of 10 g/l. Rice is the most sensitive to salinity while maize is more tolerant than millet.