Augmenting the salt tolerance in wheat (Triticum aestivum) through exogenously applied silicon

Abstract

Although silicon improves the salt tolerance in grasses, the mechanism involved is still ambiguous. Moreover in wheat, classified as Si-accumulator, silicon can alleviate the salt stress. Hence in this study, the effects of silicon using calcium silicate (150 mg/L) on the morphology, physiology and biochemistry of wheat genotypes (salt sensitive; Auqab-2000 and salt tolerant; SARC-5) differing in salt tolerance under saline (12 dS/m) and non-saline soil media (2 dS/m) were investigated. Silicon supplementation into the root medium significantly improved the K⁺ and K⁺:Na⁺ ratio, leaf water potential and stomatal conductance, but reduced the Na⁺. Plants harvested at maturity indicated a concomitant increase in number of tillers, number of grains per spike, grain and straw yield with Si application both under optimal and stressful conditions. The results suggest that Si application in soil medium is beneficial in profoundly affecting physiological phenomena and improving wheat growth under salt stress.

Keywords: Wheat, salt stress, silicon, wheat growth, K⁺:Na⁺, water potential, stomatal conductance.