Efficient Selection of Donor Lines from Gene Banks Using Genomic Approaches.

Genebanks play a critical role to preserve and disseminate germplasm. However, it is a huge task to efficiently select and utilize donor accession(s) for crop improvement. Historically, breeders have relied on the phenotypic data or passport information to select best candidates for genetic introgression, but this approach is very limited since phenotypic information is often lacking or confounded by poor agronomic backgrounds of wild germplasm and passport data is often missing or incorrect. On the other hand, the selection based on genotypic data is expected to be more efficient. We applied genotyping-by-sequencing (GBS) to 565 Aegilops tauschii accessions held at Wheat Genetics Resource Center (WGRC) at Kansas State University. With ~145k single nucleotide polymorphic (SNP) markers, we were able to identify and remove ~30% duplicated accessions from the collection. Based on this analysis, a set of unique accessions was developed, which was further scrutinized to select a smaller core set to be used in wheat breeding and improvement. Combining already existing phenotypic data for leaf rust, Hessian fly and stem rust coupled with geographical data, forty Ae. tauschii accessions were selected that represent genetically diverse group of accessions. Because of the diversity bottleneck, capturing genetically diverse accessions in wild wheat is important for the wheat improvement. Population genomic analysis revealed that these forty accessions captures >90% allelic diversity present in the population. These accessions can be prioritized for introgressing genes into breeding programs for important traits including drought and heat tolerance.