Recurrent selection and intercrossing between best of the best parents in each generation of breeding cycle resulted in a narrower genetic diversity in elite wheat (Triticum aestivum L.) germplasm. Therefore, we investigated diverse source of 143 synthetic and bread wheat accessions for identifying potentially rich genetic resources for improving the genetic diversity in wheat. This study identified 47,526 genotyping-by-sequencing-derived SNP markers that were nearly evenly distributed across three genomes of wheat. The population structure analysis identified three distinct clusters (Japan synthetics, CIMMYT synthetics, and bread wheat) of wheat genotypes on the basis of type and geographical origin of wheat accessions. Population differentiation using analysis of molecular variance indicated 21% of the total genetic variance among subgroups and the remainder within subgroups. This study also identified that the Japan synthetic group was the most divergent group compared with other subgroups. The genetic diversity comparisons between synthetic and bread wheat lines showed that the gene diversity of synthetic wheat was 33% higher than bread wheat accessions, indicating the potential use of these lines for broadening the genetic diversity of modern wheat cultivars. The results from this study will be helpful in further understanding genomic features of wheat and facilitate their use in wheat breeding programs.
Keywords: Analysis of molecular variance; Genomic diversity; Genotyping-by-sequencing; Population differentiation; SNP markers; Triticum aestivum.