Genetic and Phenotypic Diversity of a Public Soybean Breeding Program

Characterizing relationships between genotypic and phenotypic data are core aspects of germplasm development in modern breeding programs. To understand these relationships in a public breeding program close to 300 genotypes from the University of Guelph soybean breeding program were chosen for study. The genotypes chosen are from two separate University programs and consist of original founder lines, released cultivars, exotic germplasm and experimental lines. These lines were SNP genotyped using genotyping-by-sequencing and grown out in replicated two-location yield trials in summer 2015. Traits measured included yield, oil, protein, canopy traits such as normalized difference red edge index (NDRE) and several seed traits. These traits were used to understand the dynamics of selection across the genome and relate them to trait improvement over the history of the breeding program. Genome-wide association (GWA) was conducted to find genomic regions of significance for future breeding efforts. Allele flow through generations of breeding germplasm was mapped for these traits to determine the underlying selection signatures for each trait. The combined genotypic and phenotypic information will allow for better parental selection when making crosses in the breeding program by providing opportunities for allele enrichment for enhanced trait performance.