Wheat breeding for FHB resistance is a complex undertaking that relies
heavily on the genetic variation among candidate germplasm. The quantitative
nature of FHB resistance has made the task even more difficult. More than 500
QTL for FHB resistance have been detected in diverse wheat accessions
worldwide, but characterization of the genes underlying these QTL has been
limited. To improve the efficacy of the QTL in FHB resistance and to characterize
the underlying genes, we created a wheat practical haplotype graph pangenome
database using the Practical Haplotype Graph (PHG) tool. Whole exome-capture
sequencing data from 95 spring wheat genotypes used in ND, SD, MN, and MT wheat
breeding programs were used to build the PHG database. Based on the high
confidence gene models from IWGSC Refseq v1.1, a set of 94,229 reference genome
intervals were used to infer haplotypes from the wheat lines. In this ongoing
study, we estimated the accuracy of PHG -imputed genotype calls in the wheat
lines that were genotyped by exome capture, or whole-genome skim-sequencing
approach. The PHG imputation accuracy varied between 97 - 98% for the exome
capture data when compared against high confidence exome capture data
concordant with 90K array sites. The accuracy of imputed skim-sequenced data
with the PHG database ranged between 75-90%. The imputation accuracy for the
sequencing data used in this study using other imputation methods was generally
higher than the PHG but decreased as minor allele frequency increased. Further
development of the PHG database is needed to evaluate its potential for
large-scale imputation.