Genetic Variation in Responses to Salt Stress in Tunisian Populations of Medicago ciliaris

Abstract

Soil salinity is one of the most serious environmental factors affecting crop productivity around the world. We used a morpho-physiological approach to investigate the salt responses of four Tunisian natural populations of Medicago ciliaris. Forty-six lines of M. ciliaris were grown under a control treatment and 100 mM NaCl. We measured 11 quantitative traits of shoot and root growth during harvest. An analysis of variance showed that the variations in salt response can be explained by the effects of the population, line, treatment, and interactions between the population and treatment and the line and treatment. Most of the measured traits showed significant differences between the studied populations under the control treatment and salt stress. High to moderate broad-sense heritabilities (H2) were noted for most of the parameters under the control treatment and salt stress, implying that salt tolerance is highly heritable. Most correlations between the measured traits under the two treatments were positive, of which the strongest correlations were recorded between characteristics related to development. The 46 studied lines formed three groups in both conditions, while their genetic structure was dependent on the treatment factor. The results from this study can provide a basis for identifying and breeding salt-tolerant lines of M. ciliaris.

Biodiversity of the Genus Medicago from Africa

“…Analysis of morpho-physiological variability of responses to salt in four Tunisian natural populations of M. ciliaris showed that the 46 lines studied form three groups under control treatment and 100 mM NaCl, and their genetic structure is dependent on the treatment factor [27]. The results of this study can be used in the identification and selection of salt-tolerant M. ciliaris lines.…”

“…Finally, Medicago species showed a high level of variability in responses to abiotic and biotic stresses. Diversity within and among populations has been noted for water deficit [24], salinity [25][26][27], nutritional deficiencies [28], and resistance to pathogens [29][30][31][32].…”

Integrating Agro-Morpho-Physiological Traits and SSR Markers for Detecting the Salt Tolerance of Advanced Spring Wheat Lines under Field Conditions

“…Therefore, the ability of genotypes to maintain optimal water content levels in tissues is an important mechanism for counteracting the effects of salinity stress. Previous studies have also shown a moderate broad-sense heritability for RWC under salt stress conditions [24]. Accordingly, LRWC can be considered an important physiological criterion for evaluating the salt tolerance of genotypes.…”

“…This subsequently results in an imbalance in the plants' water status, specifically their LRWC, which reflects the balance between water uptake and transpiration. A reduction in LRWC can affect and alter various physiological and metabolic processes [24]. Therefore, the ability of genotypes to maintain optimal water content levels in tissues is an important mechanism for counteracting the effects of salinity stress.…”

Impact of two Erwinia sp. on the response of diverse Pisum sativum genotypes under salt stress

“…It is estimated that more than 50% of the arable soils in the world will be salinized by 2050 (Etesami et al 2022 ). In Tunisia, about 25% of the cultivated area is affected by salinity, and it is evaluated that 9.13% of the total Tunisian surface is challenged by this threat due to aridity and poor water management (Aloui et al 2022 ). The growth of crops is negatively affected by salt stress, which causes osmotic stress due to decreased water availability and ion toxicity from nutritional imbalances (Acosta-Motos et al 2017 ).…”