Biofertilizer Role in Alleviating the Deleterious Effects of Salinity on Wheat Growth and Productivity

Nowadays, there has been an increasing demand for organic agricultural products as biofertilizer that are safe for humans, livestock, environment and economically viable to reduce the negative effect of stresses on plants and stimulate crop production. Salinity is a major issue that adversely affects plant growth and productivity. The current study was carried out to investigate changes in the growth, biochemical parameters, and yield of wheat plant in response to arbuscular mycorrhizal fungi (AMF) at 1% and two levels of yeast extract at 1% and 2% under the effect of salinity levels at 4 dS/m and 8 dS/m. Results show that salinity stress caused significant decreases in vegetative growth parameters, photosynthetic pigments, indole acetic acid (IAA), grains yield/plant, carbohydrate content accompanied by significant increases in two osmolytes (total soluble sugars and proline), hydrogen peroxide (H2O2), malondialdehyde (MDA), antioxidant enzymes (Peroxidase, POD), superoxide dismutase (SOD), catalase (CAT), some antioxidant substances of the yielded grains total phenolic, flavonoid, lycopene, beta-carotene and antioxidant activity (DPPH). The deleterious effect of salinity at 8 dS/m was more than that of salinity at 4 dS/m. Since, salinity at 4 dS/m caused non significant decreases in grains yield/plant by 8.25%. Whereas, salinity at 8 dS/m significantly decreased grains yield/plant by 15.73% relative to control. Nevertheless, all applied treatments (AMF, yeast extract at 1% and 2%) alleviated the deleterious effect of both salinity levels (4 dS/m and 8 dS/m) by improving vegetative growth parameters, photosynthetic pigments, IAA, total soluble sugars and proline, H2O2, MDA, antioxidant enzymes (POD, SOD, CAT), grains yield/plant, and some biochemical constituents of the yielded grains. The most pronounced treatment was 2% yeast extract that increased shoot dry weight/plant by 48.33% under 4 dS/m salinity level and by 69.32% under 8 dS/m salinity level relative to corresponding controls. In addition, AMF, 1% yeast extract, and 2% yeast extract significantly increased grains yield/plant by 17.89%, 24.12%, and 35.41% respectively under 8 dS/m salinity stress relative to control. It could be concluded that the promotive effect of yeast extract at 2% > yeast extract at 1% > AMF in increasing wheat salinity tolerance and decreasing harmful effect of salinity on wheat growth, grain yield quality and quantity.