Abstract
The potential of seeds to germinate in soil watered by diluted natural seawater is essential to many plant species. The aim of the study was to determine the impact of dry bread yeast on germination of sorghum (Sorghum bicolor L.) and maize (Zea mays L.) seeds under salinity stress using natural "Red Sea" water. A randomized complete block design experiment with five replicates was used to determine the germination response of sorghum and maize seeds initially sown in 100%, 50% and 33.3% natural seawater and subsequently irrigated with distilled water in soil pretreated with dry bread yeast (Saccharomyces cerevisiae). Soil treated with dry bread yeast and 33.3% seawater had an enhancing effect on the emergence of sorghum and maize seedlings. In contrast, higher concentrations of seawater (100% or 50%) fully inhibited the process of germination. Results proved that 33.3% seawater accompanied by untreated soil drastically affected fresh and dry weights of shoot and root systems, chlorophyll contents, and proline and hydrogen peroxidase of maize and sorghum plants. An application of yeast significantly ameliorated the harmful effects of salinity. Accompanying this finding was a marked increase in all growth parameters studied and lower leaf hydrogen peroxide and proline accumulation compared to the untreated soil and the control. The responses of stomatal density, hairs on the adaxial sides of the leaves, and furrows of roots per unit area were determined using a scanning electron microscope. The results indicate that the number of stomata, hairs, and furrows changed in response to the salinity and the application of yeast to the soils. Hence, it could be recommended that the application of bread yeast to the soil of great physiological significance and could be used to ameliorate the harmful effects of salinity.