Comprehensive Characterization of Global Barley (Hordeum vulgare L.) Collection Using Agronomic Traits, β-Glucan Level, Phenolic Content, and Antioxidant Activities

Abstract

This study characterized the diversity of 367 barley collections from 27 different countries, including 5 control cultivars, using several phenotypic traits. Morphological traits, including spike type, grain morphology, cold damage, and lodging rate, exhibited wide variations. Eighteen accessions matured early, while four accessions had longer culm and spike lengths than the controls. The ranges of total phenolic content (TPC), β-glucan content, ABTS•+ scavenging activity, DPPH• scavenging activity, and reducing power (RP) were 1.79–6.79 mg GAE/g, 0.14–8.41 g/100 g, 3.07–13.54 mg AAE/100 g, 1.56–6.24 mg AAE/g, and 1.31–7.86 mg AAE/g, respectively. Betaone, one of the controls, had the highest β-glucan content. Two accessions had β-glucan levels close to Betaone. Furthermore, 20 accessions exhibited increased TPC compared to the controls, while 5 accessions displayed elevated ABTS•+ scavenging activity. Among these, one accession also exhibited higher DPPH• scavenging activity and RP simultaneously. Based on the statistical analysis of variance, all the quantitative traits were significantly affected by the difference in origin (p < 0.05). On the other hand, grain morphology significantly affected biochemical traits. Multivariate analysis classified barley accessions into eight groups, demonstrating variations in quantitative traits. There were noteworthy correlations between biochemical and agronomical traits. Overall, this study characterized several barley varieties of different origins, anticipating future genomic research. The barley accessions with superior performances could be valuable alternatives in breeding.

QTL Analysis of β-Glucan Content and Other Grain Traits in a Recombinant Population of Spring Barley

“…Indeed, the hull accounts for approximately 13% of the mature grain dry weight [ 37 ] and its absence causes a proportional increase in the other grain components. Hulless barleys often have higher β-glucan contents than covered feeding barley, and the former are mainly used as human food because of easier edibility [ 16 , 38 ].…”

“…Indeed, the hull accounts for approximately 13% of the mature grain dry weight [37] and its absence causes a proportional increase in the other grain components. Hulless barleys often have higher β-glucan contents than covered feeding barley, and the former are mainly used as human food because of easier edibility [16,38]. Although hulless genotypes had higher levels of phosphorous, calcium and sodium than those of covered genotypes, their ash content was lower (Table 1).…”

“…Barley cultivars commonly contain from about 4% to 10% grain β-glucan, though some low-starch mutants (with shrunken caryopses) reach contents as high as 20% [ 8 ]. Genotypes with very low β-glucan content, <1%, have been described too [ 16 ]. The level of β-glucan in the grain is strongly dependent upon the genotype [ 2 , 8 ] whereas the effects of the environment and the interaction between environments and genotypes are typically smaller [ 17 ].…”

“…Another high β-glucan barley variety, Beta-One, was developed by crossing Glacier AC38 with Shikoku Hadaka 97, which derives from Yon-M-kei 286, and was reported to contain 11.4% β-glucan [ 33 ]. In a subsequent extensive trial, however, the β-glucan content of Beta-One was found to be 8.4% [ 16 ].…”