Salinity Response in Tunisian Durum Wheat Genotypes: Genetic Relationships, Phenotypic Variation, and SSR Marker-Based Computational Modelling

Abstract

This study identifies salt-tolerant durum wheat genotypes for breeding programmes by integrating phenotypic, genotypic, and computational analyses of 27 Mediterranean varieties. Cluster analysis and principal coordinate analysis (PCoA) revealed two distinct genetic groups: modern genotypes (high-yielding Tunisian/Italian cultivars) and ancient genotypes (traditional Tunisian landraces). Among tested cultivars, JnehKhottifa and Gr & eacute;cale exhibited exceptional salinity tolerance, maintaining >80% germination at 200 mM NaCl, while Om Rabiaa and Agili showed sensitivity (<50% germination). Bayesian network modelling was used to explore the probabilistic relationships between simple sequence repeat (SSR) markers (e.g., CFD40 and GWM182, PIC = 0.561) and important traits such as root length and germination rate under stress. Genetic diversity analysis (average PIC = 0.407) highlighted the potential of SSR markers for trait-marker associations. These findings establish a valuable platform for enhancing marker-assisted selection salt-tolerant durum wheat varieties, essential for securing yields in saline-prone Mediterranean regions.