Genomic Analysis Of Spanish Wheat Landraces Reveals Their Variability And Potential For Breeding

Abstract

Background One of the main goals of the plant breeding in the 21 st century is the development of crop cultivars that can maintain current yields in unfavorable environments. Landraces that have been grown under varying local conditions include genetic diversity that will be essential to achieve this objective. The Center of Plant Genetic Resources of the Spanish Institute for Agriculture Research maintains a broad collection of wheat landraces. These accessions, which are locally adapted to diverse eco-climatic conditions, represent highly valuable materials for breeding. However, their efficient use requires an exhaustive genetic characterization. The overall aim of this study was to assess the diversity and population structure of a selected set of 380 Spanish landraces and 52 reference varieties of bread and durum wheat by high-throughput genotyping. Results The DArTseq GBS approach generated 10K SNPs and 40K high-quality DArT markers, which were mapped against the currently available bread and durum wheat reference genomes. The markers with known locations were distributed across all chromosomes with relatively well-balanced genome-wide coverage. The genetic analysis showed that the Spanish wheat landraces were clustered in different groups, thus representing genetic pools providing a range of allelic variation. The subspecies had a major impact on the population structure of the durum wheat landraces, with three distinct clusters that corresponded to subsps. durum , turgidum and dicoccon being identified. The population structure of bread wheat landraces was mainly biased by geographic origin. Conclusions The results showed broader genetic diversity in the landraces compared to a reference set that included commercial varieties and higher divergence between the landraces and the reference set in durum wheat than in bread wheat. The analyses revealed genomic regions whose patterns of variation were markedly different in the landraces and reference varieties, indicating loci that have been under selection during crop improvement, which could help to target breeding efforts. The results obtained from this work will provide a basis for future genome-wide association studies.

Genetic diversity and population structure of modern wheat (Triticum aestivum L.) cultivars in Henan Province of China based on SNP markers

“…Previous studies have examined the genetic diversity and population structure of Urartu wheat (Triticum urartu) [24], Aegilops tauschii [25], crested wheatgrass (Agropyron cristatum L.) [26], wild emmer wheat (Triticum dicoccoides) [27], durum wheat (Triticum durum) [28][29][30][31], synthetic wheat [32], and common wheat (Triticum aestivum) [3,[33][34][35][36][37][38][39][40][41] using simple sequence repeats (SSR), diversity array technology (DArT), and single-nucleotide polymorphisms (SNPs), as well as other molecular markers and analysis software. Although studies from around the world have investigated the population genetic structure and genetic diversity of wheat, no such reports have been provided for Henan Province.…”