Genome-Wide Association Mapping of Malting Quality Traits in Relevant Barley Germplasm in Uruguay

摘要

Knowledge about the genetic components of major malting quality traits is needed for efficient barley breeding, and although some of these traits have been mapped, little information about germplasm-specific QTL is known for South American germplasm. The aim of this study was to determine by genome-wide association mapping the key genetic basis of malting quality traits in a population of 76 different genotypes, consisting of historical varieties, commercial cultivars and advanced lines representative of barley breeding in Uruguay. Samples obtained in five contrasting environments were micromalted in order to obtain a phenotypic database. The population was genotyped with 1,033 polymorphic SNPs using the Illumina BOPA1. Marker-trait associations were detected through linkage disequilibrium mapping using a mixed linear model (MLM) Q+K containing a structure matrix (PCA) and a kinship matrix (K). Preliminary results showed QTL effects detected for all traits, with some genomic regions showing a high concentration of significant associations. Most QTL were environment-specific. We are presently studying the relationship between malting quality traits and linkage disequilibrium blocks found in the population. The results provide some of the first data regarding genetic basis of malting quality relevant traits in the germplasm used in the region.