Increased soil salinity significantly inhibits crop production around the world. Over the last decade, biochar has been used in agriculture to improve plant productivity, soil quality, and as an alternative to plant amendment. This study was aimed to study the effect of biochar, NPK, and their combination on the growth, physio-biochemical traits, mineral contents, and grain yield of barley (Hordeum vulgare L.). Thus, a pot factorial experiment based on a completely randomized design with three replications was performed. Experimental treatments included four levels of biochar (0, 2, 5 and 10% of total pot mass), four different NaCl levels (0, 75, 125, and 200 mmol L⁻¹), and with or without NPK fertilizer. The results showed that a negative effect on gas exchange parameters, photosynthetic pigments, SPAD value, minerals contents, and grain yield of barley under salinity treatments. In addition, our funding showed the negative effect on biochemical traits such as proline, soluble sugars, individual sugar, and phenolic compounds. The use of biochar, combined with NPK fertilizers, considerably increases these parameters and especially improves barley grains yield under severe salinity conditions (200 mM) with a dose of 2% and 5% (394.1 and 280.61 g m⁻², respectively) of total pot mass. It is concluded that biochar amendment could be a promising practice to enhance barley growth under severe saline irrigation and NPK fertilization regimes.

Pearl millet (Pennisetum glaucum (L.) R. Br., 2n = 2x = 14, Poaceae), is a cross-pollinated, warm-season crop grown worldwide. To select genotypes for breeding pearl millet cultivars that adapt to drought condition in southern Tunisia, we evaluated the grain yield (GY) and yield-related traits using a set of 27 landraces at two locations in southern Tunisia for two grown seasons (2019 and 2020). The genetic variability, phenotypic and genotypic association, and path coefficient (PC), based on grain yield (GY) and different yield-related agronomic traits, were evaluated. Analysis of variance and BLUPs value revealed a wide range of variability and the possibility of genetic selection for traits that are advantageous. Broad sense heritability (H) for all the traits ranged from 24.10% for grain yield (GY) to 57.11% for spike length (SL), indicating low to moderate inheritability. Genetic advance as a percentage of the mean (GAM) ranged from high (29.56%) for principal panicle weight (PPW) to moderate for all the traits except from plant high (PH) (7.31%). For all the traits, the phenotypic coefficient of variation (PCV) was higher than genotypic coefficient of variation (GCV), indicating the magnitude of environmental conditions. GY was significantly correlated with all the traits at the genotypic and phenotypic level. According to the path coefficient, the traits PPW and SL displayed the highest direct effects on GY. Heatmap analysis demonstrated a clear segregation between the early and late genotypes based on their geographic origin. Based on the cluster analysis and FAI-BLUPS analysis, genotypes G11, G13, G12, G17 and G18 were selected as the best-performing genotypes with the shortest cycle.

Salinity stress severely limits barley production by disrupting physiological and biochemical processes critical for growth and yield. Although numerous studies have examined individual physiological or antioxidant responses to salinity, an integrated multivariate understanding of how these mechanisms collectively contribute to yield stability at the flowering stage remains limited. This study aimed to elucidate the integrated antioxidant and physiological mechanisms underlying salinity tolerance in barley genotypes during flowering. Barley plants were subjected to controlled salinity treatments, and a comprehensive set of phenolic compounds, antioxidant capacity indices, physiological traits, and yield components were measured. Multivariate analyses, including redundancy analysis (RDA) and partial least squares regression (PLSR), identified key traits contributing to yield stability under salinity. Multivariate analyses revealed also genotype-specific physiological strategies underlying contrasting salinity tolerance levels. Antioxidant defenses, such as total phenolics, DPPH and ABTS radical scavenging activities, and α-tocopherol, along with osmotic regulators like proline and soluble sugars, were closely associated with improved water status and reduced oxidative damage. These coordinated responses correlated strongly with yield components, including thousand-grain weight and main spike seed number. Notably, this study provides new insights into the predictive relevance of selected biochemical and physiological markers for yield performance under salt stress using PLSR at the flowering stage. PLSR further demonstrated the high predictive power of a limited subset of biochemical and physiological markers for yield traits under salt stress. Collectively, these findings reveal that the interplay between antioxidant machinery and osmotic adjustment at flowering is critical for barley resilience to salinity, providing valuable physiological markers to inform breeding strategies aimed at improving salt tolerance.

Soil salinity is one of the most brutal environmental factors that affect crop growth and productivity. Chenopodium quinoa is known as one of the essential food crops in the future due to its agronomic and nutritive value and its strong adaptability to stress environments and soil conditions. However, the molecular aspects of salt tolerance of quinoa remain not well known. Therefore, the expression study of candidate genes related to salt tolerance has become one of the most important features for the identification of their functions. However, one of the most crucial points in Quantitative PCR (qPCR) data analysis is the selection of appropriate reference gene that should be stable and unaffected in a given condition. In this study, six candidate reference genes were analysed in order to select the most stable one under salt stress conditions. The expression stability was assessed using three different algorithms: geNorm, NormFinder and BestKeeper. The most stable and appropriate reference genes screened in this study whose expression was confirmed to be constant in different salt treated and untreated quinoa plant were Monensin sensitivity1 (MON1) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and Factor elongation 1-alpha (EF-1α), while Ubiquitin-conjugating enzyme (UBC) and Ubiquitin-protein ligase 7 (UPL7) had the worst stability. However, the data obtained by BestKeeper demonstrated slight differences compared to those from geNorm and NormFinder. Overall, we designated MON1 and GAPDH as the best candidates and the most stable housekeeping gene under salt stress conditions and their geometric means would provide accurate normalization factor for expression data in Chenopodium quinoa.