Whole genome association mapping identifies naked grain locus NUD as determinant of β-glucan content in barley

ß-glucan content in barley grain is an important component in determination of seed quality and end use. While high ß-glucan content is considered beneficial for human food, it is undesirable in malting barley and feed. Association of ß-glucan content in grain of 89 barley accessions of Latvian origin including 22 hulless accessions with 1273 high quality genome wide Single Nucleotide Polymorphism markers was tested. P-values were calculated using mixed linear model combining Q matrix and K matrix by computer program Tassel. P-values were adjusted using Bonferroni correction. Significant associations were identified for three markers 1_0673 (114.58 cM), 2_0880 (116.68 cM) and 1_1445 (116.68 cM) on chromosome 7H bin 7. Recessive mutation in the NUD locus also located on chromosome 7H bin 7, which determines hulless barley phenotype and has been previously suspected to affect ß-glucan content, was also genotyped and included in the association analysis.Asignificant marker - trait association was found identifying NUD gene as a major source of variation for ß-glucan content in our association mapping panel.