Molecular and Agro-Morphological Diversity of Undercharacterized Local Bread Wheat Genetic Resources from Serbia and Bulgaria

Unlocking the potential for adaptability across different conditions or environments of under-characterized local bread wheat from Serbia and Bulgaria remains critical for resilient breeding. This study aimed to assess the diversity and potential for adaptability of 76 accessions (35 from Serbia and 41 from Bulgaria) by integrating molecular and agro-morphological approaches. Plant height ranged from 101.1 cm in Bulgarian cultivars to 130.1 cm in Serbian landraces, while the flowering time varied from 134.9 days in Bulgarian cultivars to 139.7 days in Serbian landraces. SSR markers detected 446 alleles (mean 9.49 per locus; PIC = 0.646), with Serbian landraces exhibiting the highest allelic richness (7.23 alleles per locus) and 106 private alleles. Bayesian clustering and UPGMA analyses revealed clear genetic differentiation between Serbian and Bulgarian accessions, with Serbian landraces showing higher admixture and substructure. Principal coordinate analysis confirmed these patterns and highlighted the intermediate positions of pre-Green Revolution Serbian cultivars. The local wheat germplasm harbors high genetic diversity and potential for adaptability, particularly for traits critical to environmental resilience. These findings underline the value of local wheat germplasm as a resource for developing sustainable breeding and conservation strategies.