Low leaf sodium content improves the grain yield and physiological performance of wheat genotypes in saline-sodic soil

Baixo teor de sódio nas folhas melhora o rendimento de grãos e o desempenho fisiológico de genótipos de trigo em solo salino-sódico

ABSTRACT

Salt stress is a major production constraint in wheat. The maintenance of a low Na⁺ accumulation in the leaves may improve the tissue tolerance against salt stress. A field experiment was conducted to discriminate twenty wheat genotypes, based on leaf Na⁺ accumulation as a criterion for salt tolerance, and evaluate the effect of sodium accumulation on the biomass production, physiological and yield traits of wheat genotypes grown in a saline-sodic environment. The Na⁺ concentration was determined in young fully expanded leaves at the vegetative growth stage. The genotypes were categorized into two contrasting groups (with low and high Na⁺ content), in a randomized complete block design, with three replications. The low Na⁺ genotypes (V-03094, V-02156, TURACO, V0005 and PVN) showed much longer chlorophyll retention, leaf K⁺ content, proline and phenolic contents than the high Na⁺ genotypes. The salt effects on yield components were also less in the wheat genotypes with low leaf Na⁺ content than the high Na⁺ genotypes. The greater grain yield of low Na⁺ accumulating genotypes was due to the enhanced grain number and weight in their tillers, which were strongly associated with the higher Na⁺ efflux from the leaves. The low sodium accumulator genotypes improved the seedling emergence (%) and grain yield in saline-sodic soil.

KEYWORDS:
Triticum aestivum L.; salt stress; salt tolerance