Genetic characterization and curation of diploid A-genome wheat species. Issue 4 (3rd February 2022)

• Record Type: Journal Article
• Authors: Adhikari, Laxman; Raupp, John; Wu, Shuangye; Wilson, Duane; Evers, Byron; Koo, Dal-Hoe; Singh, Narinder; Friebe, Bernd; Poland, Jesse
• Is Part Of: Plant physiology. Volume 188:Issue 4(2022)
• Page Start: 2101
• Page End: 2114
• Publication Date: 2022-02-03
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1093/plphys/kiac006
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract: A-genome diploid wheats represent the earliest domesticated and cultivated wheat species in the Fertile Crescent and include the donor of the wheat A sub-genome. The A-genome species encompass the cultivated einkorn ( Triticum monococcum L. subsp. monococcum ), wild einkorn ( T . monococcum L. subsp. aegilopoides (Link) Thell.), and Triticum urartu . We evaluated the collection of 930 accessions in the Wheat Genetics Resource Center (WGRC) using genotyping by sequencing and identified 13, 860 curated single-nucleotide polymorphisms. Genomic analysis detected misclassified and genetically identical (>99%) accessions, with most of the identical accessions originating from the same or nearby locations. About 56% ( n = 520) of the WGRC A-genome species collections were genetically identical, supporting the need for genomic characterization for effective curation and maintenance of these collections. Population structure analysis confirmed the morphology-based classifications of the accessions and reflected the species geographic distributions. We also showed that T . urartu is the closest A-genome diploid to the A-subgenome in common wheat ( Triticum aestivum L.) through phylogenetic analysis. Population analysis within the wild einkorn group showed three genetically distinct clusters, which corresponded with wild einkorn races α, β, and γ described previously. The T . monococcum genome-wide FST scan identified candidate genomic regions harboring a domestication selection signature at the Non-brittle rachis 1 ( Btr1 ) locus on the short arm of chromosome 3A m at ∼70 Mb. We established an A-genome core set (79 accessions) based on allelic diversity, geographical distribution, and available phenotypic data. The individual species core set maintained at least 79% of allelic variants in the A-genome collection and constituted a valuable genetic resource to improve wheat and domesticated einkorn in breeding programs. Abstract : Genotyping diploid A-genome relatives of wheat uncovered high genetic diversity and unique evolutionary relationships giving insight to the effective use of this germplasm for wheat improvement.