SSR-based genetic diversity assessment among varieties conserved in a Romanian grapevine (Vitis vinifera L.) collection

The present study highlights the genetic relationships among 52 grapevine varieties, including traditional and newly developed Romanian varieties and international reference cultivars, held in a small didactic ampelographic collection in Iaşi, Romania, and their genetic diversity, assessed using multivariate analysis. Twelve nuclear simple sequence repeat (SSR) markers, including nine OIV-standard descriptors, were used for genetic profiling. A total of 102 alleles were identified, with an average of 8.5 alleles per locus. The mean polymorphic information content (PIC) of 0.779 confirmed the high discriminatory power of the chosen markers. NJ dendrogram and PCoA yielded mostly similar results but did not clearly differentiate genotypes based on the selected criteria for genotype comparison (usage or historical status). STRUCTURE analysis assigned genotypes to SSR-group 1 (23.07%) and SSR-group 2 (34.61%) under K = 2 and a Q-value threshold of 0.85. The high proportion of admixed genotypes (42.32%) may reflect complex pedigrees and the migration of grapevine varieties across a wider territory surrounding Romania. The present research may serve as a starting point for future studies in Romania on the genetic structure and parental analysis of grapevine varieties held in small didactic collections, aiming to characterize and hold valuable grapevine varieties under secure conditions for future generations.