We genetically dissected a large collection of about 1,041 Aegilops accessions distributed among 23 different species using over forty thousand single nucleotide polymorphisms (SNPs) identified by genotyping-by-sequencing (GBS). Alongside the WGRC gene bank curation, we performed genomic analysis to uncover the evolutionary relationships among different Aegilops species. We observed that each Aegilops species has a unique genetic and evolutionary relationship with every other Aegilops species
In this comprehensive study, we genetically dissected a large collection of about 1,041 Aegilops accessions distributed among 23 different species using more than forty thousand single nucleotide polymorphisms (SNPs) identified by genotyping-by-sequencing (GBS). The Wheat Genetics Resource Center (WGRC) Aegilops germplasm collection was curated with the identification of misclassified and redundant accessions. There were about 50 misclassified Aegilops accessions and 27 redundant accessions within the four diploid species, which were curated with reference-based SNP markers. The curated germplasms now have improved utility for genetic studies and wheat improvement.  We constructed a robust phylogenetic tree and PCA cluster for all Aegilops species together, perhaps the most representative Aegilops genetic tree published so far. The U genome Aegilops clade and the Sitopsis section species were further scrutinized with in-depth population analysis. The genetic relatedness among the pairs of Aegilops species provided a strong clue for the species' evolution, speciation, and diversification. We inferred genome symbols for two species, Ae. neglecta and Ae. columnaris, based on the amount of sequence read mapping and the presence of segregating loci on the pertinent genomes, as well as genetic clustering. The higher and variable genetic diversities observed among the Aegilops population indicate that the genus can play a critical role in providing untapped genetic diversity for future wheat breeding and improvement.