In recent years, barley has attracted more interest as a food and feed source because of its high soluble dietary fiber and β-glucan content compared with other small grains. Twenty-five barley genotypes (20 imported genotypes and five check cultivars) were grown in three environments for two successive seasons: 2015/2016 and 2016/2017. The first environment was in El-Nubaria, Alexandria, Egypt during 2015/2016, while the second and third environments were in El-Bostan, Elbhera, Egypt during 2015/2016 and 2016/2017. The experiments were conducted in a randomized complete block design with the three replicates. The primary objectives of the current study were to evaluate the performance of 20 imported barley genotypes under several environmental conditions. The imported materials were superior to the local commercial cultivars for several traits, including grain yield. Therefore, the superior genotypes will be further evaluated and used in barley breeding programs. Our future work will focus on creating several crosses among the selected superior genotypes to improve yield and other important traits, while applying marker-assisted selection.

In the current study, 248 two-rowed and another 253 six-rowed spring barley (Hordeum vulgare L.) breeding lines from several US barley breeding programs were evaluated in multiple locations in Egypt to select for potentially adapted lines. The introduced plant materials were planted in two locations during three growing seasons (2015, 2016, and 2017). The focus of the first growing season was to increase available seeds and collect preliminary observations. During the second and third growing seasons, the advanced plant materials and local check cultivars were planted in an incomplete block design in two replicates within three locations. Grain yield, leaf rust, number of days to flowering, and plant height were measured. Based on grain yield production, the top 94 lines from the two-rowed and 100 from the six-rowed barley lines were selected and advanced for further evaluation in 2017. The introduced materials contained several lines that consistently outperformed the check cultivars. Therefore, these lines could be used as parents to improve barley production and enhance genetic diversity or be directly released as cultivars after appropriate testing in Egypt.

Drought tolerance is a main trait for growing and stabilizing barley productivity in dry areas globally. The current study was conducted to evaluate the morphological and yield-related traits of the barley cultivar "Giza134" in response to drought stress. To determine the impact of drought and stress, the experiment was conducted in the growth chamber and in rainfed conditions. In the growth chamber, seedlings were irrigated, watered (normally), and subjected to 30% PEG-600 (polyethylene glycol 600) as a drought stress condition. Furthermore, barley plants were evaluated during two consecutive seasons, 2021 and 2022, at Nubaria (normal condition), in addition to two different rainfed locations on the northwest coast of Egypt, West Barrani and East Matrouh. Most morphological and yield component traits declined significantly, including plant height (cm), spike length (cm), number of grains per spike, biological yield (BY; ton/fed-1), and grain yield (GY; Ardab Fed-1). Grain yield losses were over 85% in West Barrani and East Matrouh, respectively, compared with Nubaria. To understand the mechanisms of drought tolerance at the molecular level, the gene expression of drought-responsive genes, including HvAPX1 encodes peroxidase, HvFNR encodes ferredoxin-NADP+ reductase, HvDHN1 encodes dehydrin, HvSAM encodes Sadenosyl-L-methionine methyltransferases, HvEDE encodes ER degradation enhancer, and HVABH encodes alpha/beta-hydrolases, were measured in leaf tissues of "Giza 134." The relative expression levels of HvAPX1, HvFNR, and HvDHN1 were significantly (p 0.01) upregulated, with over 8-fold for HvDHN1. while HvSAM, HvEDE and HVABH genes are downregulated in response to drought stress. These findings might provide new insights into the mechanisms of drought tolerance in barley and facilitate future breeding programs for resilient barley crops in a changing global climate.

Barley (Hordeum vulgare L.) thrives in the arid and semi-arid regions of the world; nevertheless, it suffers large grain yield losses due to drought stress. A panel of 426 lines of barley was evaluated in Egypt under deficit (DI) and full irrigation (FI) during the 2019 and 2020 growing seasons. Observations were recorded on the number of days to flowering (NDF), total chlorophyll content (CH), canopy temperature (CAN), grain filling duration (GFD), plant height (PH), and grain yield (Yield) under DI and FI. The lines were genotyped using the 9K Infinium iSelect single nucleotide polymorphisms (SNP) genotyping platform, which resulted in 6913 high-quality SNPs. In conjunction with the SNP markers, the phenotypic data were subjected to a genome-wide association scan (GWAS) using Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK). The GWAS results indicated that 36 SNPs were significantly associated with the studied traits under DI and FI. Furthermore, eight markers were significant and common across DI and FI water regimes, while 14 markers were uniquely associated with the studied traits under DI. Under DI and FI, three (11_10326, 11_20042, and 11_20170) and five (11_20099, 11_10326, 11_20840, 12_30298, and 11_20605) markers, respectively, had pleiotropic effect on at least two traits. Among the significant markers, 24 were annotated to known barley genes. Most of these genes were involved in plant responses to environmental stimuli such as drought. Overall, nine of the significant markers were previously reported, and 27 markers might be considered novel. Several markers identified in this study could enable the prediction of barley accessions with optimal agronomic performance under DI and FI.