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Sugar beet (Beta vulgaris L. ssp. vulgaris Doell.) was originally selected from white fodder beet in the 1780s and was then specifically bred for sucrose production. The relatively recent inception of the crop has led to a narrow genetic base that has bottlenecked sustainable improvement. To evaluate the potential of publicly available germplasm for sugar beet improvement, genetic diversity analysis with SNPs (single‐nucleotide polymorphisms) covering the whole genome of sugar beet was conducted using 1936 publicly available germplasm lines in the United States. The results confirmed the narrow genetic base of sugar beet and identified germplasm accessions with inherently greater diversity that were mostly accessions of wild sea beet (B. vulgaris ssp. maritima (L.) Arcang.), the progenitor species of white fodder beet. These wild accessions displayed a distinct genetic relationship from cultivated sugar beet lines, indicating their high potential for broadening sugar beet genetic diversity. Analysis of historic resistance evaluations also suggested a higher potential of B. vulgaris ssp. maritima accessions to be used as sources of resistance to major diseases and insects of sugar beet. A genome‐wide association study using historic evaluation data identified genomic regions significantly associated with disease and insect resistance. However, genomic regions associated with resistance to nematode, insects, or diseases vectored by insects were of low significance, indicating the need for additional research to allow for a more precise evaluation of germplasm responses to insects. The research confirms that accessions of B. vulgaris ssp. maritima are potentially valuable for improving biotic stress resistance and broadening the genetic base of sugar beet. Core Ideas: Analyzed genetic diversity of publicly available Beta vulgaris germplasm.Potential of the available germplasm for sustainable sugar beet improvement.Association mapping to identify genomic regions associated with pest resistance using historic evaluation data. [ABSTRACT FROM AUTHOR]

Landraces are considered a valuable source of potential genetic diversity that could be used in the selection process in any plant breeding program. Here, we assembled a population of 600 bread wheat landraces collected from eight different countries, conserved at the ICARDA's genebank, and evaluated the genetic diversity and the population structure of the landraces using single nucleotide polymorphism (SNP) markers. A total of 11,830 high-quality SNPs distributed across the genomes A (40.5%), B (45.9%), and D (13.6%) were used for the final analysis. The population structure analysis was evaluated using the model-based method (STRUCTURE) and distance-based methods [discriminant analysis of principal components (DAPC) and principal component analysis (PCA)]. The STRUCTURE method grouped the landraces into two major clusters, with the landraces from Syria and Turkey forming two clusters with high proportions of admixture, whereas the DAPC and PCA analysis grouped the population into three subpopulations mostly according to the geographical information of the landraces, i.e., Syria, Iran, and Turkey with admixture. The analysis of molecular variance revealed that the majority of the variation was due to genetic differences within the populations as compared with between subpopulations, and it was the same for both the cluster-based and distance-based methods. Genetic distance analysis was also studied to estimate the differences between the landraces from different countries, and it was observed that the maximum genetic distance (0.389) was between the landraces from Spain and Palestine, whereas the minimum genetic distance (0.013) was observed between the landraces from Syria and Turkey. It was concluded from the study that the model-based methods (DAPC and PCA) could dissect the population structure more precisely when compared with the STRUCTURE method. The population structure and genetic diversity analysis of the bread wheat landraces presented here highlight the complex genetic architecture of the landraces native to the Fertile Crescent region. The results of this study provide useful information for the genetic improvement of hexaploid wheat and facilitate the use of landraces in wheat breeding programs. [ABSTRACT FROM AUTHOR]