Document Type : Review Paper
Authors
1
Research Assistant Professor, National Salinity Research Center, Agricultural Research, Education and Extension Organization (AREEO), Yazd, Iran.
2
Associate Professor, Department of Agronomy and Plant Breeding, Faculty of Agriculture, Yasouj University, Yasouj, Iran
3
Professor, Department of Plant Production and Genetics, Faculty of Agriculture, Shiraz University, Shiraz, Iran
4
Research Associate Professor, National Salinity Research Center, Agricultural Research, Education and Extension Organization (AREEO), Yazd, Iran
10.22124/cr.2026.32537.1886
Abstract
Introduction
Salinity is recognized as one of the most detrimental abiotic stresses, severely affecting the growth and productivity of agricultural crops and posing a significant threat to global food security. Given the time-consuming and costly nature of physically restoring saline ecosystems, the development of salt-tolerant cultivars in strategic cereals such as rice, wheat, and maize is considered a sustainable and cost-effective approach to address this challenge. This review aims to explore recent advances in understanding the mechanisms of salinity tolerance and to introduce modern breeding tools that can accelerate the development of such cultivars.
Research findings
Studies indicate that salinity tolerance mechanisms particularly osmotic adjustment vary significantly among plant species. For instance, barley exhibits higher tolerance due to its superior osmotic regulation capacity, whereas sensitive species like maize are more limited in this regard. At the molecular level, the identification of numerous quantitative trait loci (QTLs) and functional genes (e.g., SOS1, HKT1, and NHX1) involved in ion homeostasis and the accumulation of protective compounds has opened new avenues for molecular breeding. Although conventional breeding methods have achieved some success in developing salt-tolerant varieties, they are often inefficient, time-intensive, and environmentally dependent. Moreover, phenotypic evaluation of salinity tolerance under field conditions may not always reflect actual plant performance, highlighting the urgent need for standardized and reliable assessment methods. A major challenge lies in the simultaneous and stable introgression of multiple effective genes / QTLs into elite genetic backgrounds, as salinity tolerance is a complex quantitative trait. Relying on one or a few individual genes is insufficient to achieve durable resistance under field conditions.
Conclusion
Modern plant breeding tools such as marker-assisted selection (MAS), genome-wide association studies (GWAS), and especially omics technologies (transcriptomics, proteomics, and metabolomics), along with genome editing, have revolutionized the identification and transfer of desirable genes. These technologies enable precise and rapid gene pyramiding and the simultaneous transfer of multiple salinity-resistance alleles.
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