Salinity stress amelioration and morpho-physiological growth stimulation by silicon priming and biochar supplementation in Chenopodium quinoa

The effect of silicon (Si) priming and soil amendment with biochar (BC) was analysed in Chenopodium quinoa under normal and salinity stressed conditions. Reduced growth parameters, chlorophyll content, and photosynthesis under salinity stress were significantly ameliorated by Si priming and soil amendment with BC. Applied Si and BC treatment also enhanced the chlorophyll content, stomatal conductance, transpiration rate, net photosynthesis, and maximal photochemical efficiency. In addition to this, Si and/or BC amendments alleviated the oxidative damage by reducing the generation of toxic reactive oxygen species including hydrogen peroxide and superoxide. Moreover, the activities of antioxidant enzymes and the content of ascorbate and glutathione increased significantly in Si and BC treated plants reflecting efficient alleviation of oxidative damage. Besides, the content of compatible osmolytes was increased in Si and/or BC treated seedlings, thereby contributing to improved growth and salinity tolerance by maintaining higher leaf water potential and water use efficiency. Si and BC treatment increased the uptake of key mineral elements. Moreover, salinity induced decline in the nutritional components of seeds of C. quinoa were considerably increased under Si and BC treatments.