Characterization of a Wild Barley Multiparent Advanced Backcross Population

The availability of wild barley germplasm for the improvement of cultivated barley is limited by the confounding presence of unadapted traits. To minimize these confounding effects, while still capturing a large amount of genetic diversity from wild barley, we developed a 798 line multiparent advanced backcross population with 25 wild barley accessions backcrossed to the Minnesota 6-row malting barley cultivar Rasmusson.  The 25 wild barley accessions were selected to maximize the allelic diversity found in the University of Minnesota’s 318 accession Wild Barley Diversity Collection.  Based on over 4,000 SNP, DArT, and SSR markers, these 25 accessions capture more than 90% of the allelic diversity found in the entire collection. To genetically and phenotypically characterize the population, a custom 384-SNP Illumina GoldenGate assay was developed, and the population was grown in augmented field trials in Crookston and St. Paul, Minnesota in the summer of 2012.  The genotypic data shows introgressed regions of the wild barley parent genomes ranging from 85-99% for each individual BC2F4:6 family. Traits scored in the population include height, heading date, productive tiller count, and yield, and evidence for transgressive segregation is apparent within several families.  To explore the genetic architecture of these traits in this diverse population, QTL will be mapped using an association mapping approach.