Assessing genetic diversity and developing traceability tools for the Sicilian tetraploid wheat conservation varieties supply chain

Durum wheat landraces and historical varieties, commonly referred to as conservation varieties, are gaining an increasing interest lately, due to their agronomic, cultural, and economic significance. In Sicily, these varieties are still cultivated and play a crucial role in supporting local agricultural systems. To promote their value and ensure product authenticity along the supply chain, reliable traceability tools are needed. We performed SNP genotyping on a collection of 181 tetraploid wheat accessions using the Illumina Infinium 7K SNP array. The panel included 141 accessions representing six key Sicilian conservation varieties (Bidì, Perciasacchi, Ruscìa, Russello, Timilia reste bianche, and Timilia reste nere) and 40 additional accessions comprising Italian landraces, historical cultivars, and modern varieties used as references. Of these, 139 accessions belonged to Triticum turgidum ssp. durum , while 42 were identified as T . turgidum ssp. turanicum . Clustering analyses based on multi-locus genotypes and identity-by-state distances revealed several misidentified accessions, likely due to seed lot contamination maintained at the farm level. Notably, Russello, Ruscìa, and Timilia showed marked genetic divergence from both traditional and modern cultivars, underscoring their distinct genetic identities. In contrast, Turanicum accessions displayed low genetic differentiation, suggesting a shared origin and limited diversification. From the overall dataset, 18 SNP markers were identified as highly effective for distinguishing Sicilian conservation varieties. Kompetitive Allele-Specific PCR (KASP) assays were developed and validated for these markers, providing the foundation for a robust, DNA-based traceability system applicable throughout the conservation variety supply chain. • Genotyping of conservation varieties is essential to avoid genetic contamination • Timilia, Ruscìa and Russello showed unexploited genetic variability • Genetic traceability of conservation varieties can be achieved using KASP assays