Genetic structure of a collection of soybean accessions of different geographical origin based on SSR loci polymorphism

Background. Assessment of genetic diversity and genetic structure is essential for effective soybean breeding and conservation of genetic resources. The present study aimed to evaluate the genetic variability of 29 soybean accessions originating from six countries using nine microsatellite (SSR) loci. Materials and Methods. The collection included cultivars developed in Ukraine and introduced genotypes from Canada, Austria, France, Germany, and Serbia. Each accession was represented by a single bulk DNA sample composed of embryonic root segments from 30 seeds. Nine SSR markers recommended by the NY/T 2595-2014 standard were amplified. Genetic diversity parameters were estimated using Nei’s genetic diversity index, and genetic grouping was inferred using Bayesian clustering implemented in STRUCTURE software. Results and Discussion. Eight of the nine loci were polymorphic, yielding a total of 18 alleles with an average of 2.0 alleles per locus. Nei’s genetic diversity index (He) ranged from 0.07 to 0.51 (mean 0.26). Pairwise genetic distances varied from 0.0002 to 0.0499. No identical multilocus SSR profiles were detected among the loci analyzed. Bayesian clustering analysis revealed three major genetic groups (K = 3). Twenty-five accessions were assigned to the “pure” group (Q ≥ 0.80), whereas four exhibited admixed genetic structure (Q < 0.80). Conclusions. The results confirm the suitability of SSR markers for cultivar differentiation, assessment of genetic diversity, and analysis of genetic grouping within soybean collections. Partial correspondence between clusters and geographical origin suggests shared breeding history and germplasm exchange. The obtained data may support breeding program optimization and conservation of soybean genetic resources.