Allelic shifts and quantitative trait loci in a recurrent selection population of oat

Recurrent selection to enhance grain yield of oat (Avena sativa L.) has bee n ongoing at the University of Minnesota since 1968. Grain yield was increa sed by 21.7% after seven cycles of recurrent selection. The objectives of t his study were to monitor the long-term genetic changes in this recurrent s election population using restriction fragment length polymorphisms (RFLPs) . Ninety-seven RFLP loci detected by 73 cDNA clones were used to evaluate c hanges in allelic frequencies during the recurrent selection process. Signi ficant allelic shifts were detected in eight genomic regions. Four linkage groups were studied in greater detail to localize putative quantitative tra it loci (QTL). In total, seven primary or major QTL regions were identified using allelic shift, correlation, and single-factor analysis of variance ( ANOVA) data. Six of these regions were associated with grain yield and one was associated with plant height. Thirty-three other minor QTL were detecte d using correlation and/or ANOVA data. Multiple regression models for grain yield, heading date, and plant height indicated that associated markers ac counted for 30, 38, and 27% of the phenotypic variance, respectively. Our r esults indicate that we have identified genomic regions containing favorabl e alleles selected during the recurrent selection process. Thirteen of the 40 QTL identified for the individual traits in the recurrent selection popu lation were previously identified in the Kanota X Ogle recombinant inbred m apping population. Therefore, these QTL may be generally important in oat.