Quantitative trait loci influencing beta-glucan content in oat (Avena sativa, 2n=6x=42)

The beta -glucan content of oat grain is of interest due to its positive hu man health role as a dietary component influencing serum cholesterol levels and its relation to the energy intake of livestock feed. Two recombinant i nbred populations sharing a common parent (Kanota x Ogle and Kanota x Mario n), and containing 137 individual lines each, were used to identify genomic regions that influence the beta -glucan content in cultivated oat. Single- factor ANOVA, a backward elimination process, simple interval mapping (SIM) and simplified composite interval mapping (sCIM) were used to identify qua ntitative trait loci (QTLs). Regions on linkage groups 11 and 14 of the hex aploid oat RFLP map influenced beta -glucan levels in both populations and over environments. Other genomic regions were identified whose effects vari ed depending on the genetic background, but were significant over measureme nts for a given population. Kanota and Ogle exhibit similar beta -glucan le vels and each parent contributed about the same number of positive beta -gl ucan alleles in the Kanota x Ogle cross. Marion is higher in beta -glucan c ontent than Kanota and contributed all of the positive alleles in the Kanot a x Marion cross. Three of the beta -glucan QTL regions identified have bee n previously implicated as having a significant influence on the great oil content in oat. These correlated QTL regions were either in coupling phase, with a region from one parent having the same effect on both traits, or we re in repulsion phase. Identification of coupling- and repulsion-phase QTL regions for beta -glucan and oil content facilitates the use of markers in manipulating these traits in oat breeding.