National Research Council of Canada. Aquatic and Crop Resource Development
BACKGROUND: Common bean (Phaseolus vulgaris) is an important grain legume and there has been a recent resurgence
in interest in its relative, tepary bean (P. acutifolius), owing to this species’ ability to better withstand abiotic
stresses. Genomic resources are scarce for this minor crop species and a better knowledge of the genome-level
relationship between these two species would facilitate improvement in both. High-throughput genotyping has
facilitated large-scale single nucleotide polymorphism (SNP) identification leading to the development of molecular
markers with associated sequence information that can be used to place them in the context of a full genome assembly.
RESULTS: Transcript-based SNPs were identified from six common bean and two tepary bean accessions and a subset
were used to generate a 768-SNP Illumina GoldenGate assay for each species. The tepary bean assay was used to assess
diversity in wild and cultivated tepary bean and to generate the first gene-based map of the tepary bean genome.
Genotypic analyses of the diversity panel showed a clear separation between domesticated and cultivated tepary beans,
two distinct groups within the domesticated types, and P. parvifolius was confirmed to be distinct. The genetic map of
tepary bean was compared to the common bean genome assembly to demonstrate high levels of collinearity between
the two species with differences limited to a few intra-chromosomal rearrangements.
CONCLUSIONS: The development of the first set of genomic resources specifically for tepary bean has allowed for greater
insight into the structure of this species and its relationship to its agriculturally more prominent relative, common bean.
These resources will be helpful in the development of efficient breeding strategies for both species and will facilitate the
introgression of agriculturally important traits from one crop into the other.