Autochthonous Austrian Varieties of Prunus avium L. Represent a Regional Gene Pool, Assessed Using SSR and AFLP Markers

Sweet cherry production faces new challenges that necessitate the exploitation of genetic resources such as varietal collections and landraces in breeding programs. A harmonized approach to characterization is key for an optimal utilization of germplasm in breeding. This study reports the genotyping of 63 sweet cherry accessions using a harmonized set of 11 simple sequence repeat (SSR) markers optimized in two multiplexed PCR reactions. Thirty-eight distinct allelic profiles were identified. The set of SSR markers chosen proved highly informative in these germplasm; an average of 6.3 alleles per locus, a PIC value of 0.59 and above-average expected and observed heterozygosity levels were detected. Additionally, 223 amplified fragment length polymorphism (AFLP) markers derived from eight selective primer combinations were employed to further differentiate 17 closely related accessions, confirming the SSR analysis. Genetic relationships between internationally known old cultivars were revealed: SSR fingerprints of Schneiders Spate Knorpelkirsche and Germersdorfer were found to be identical to those of the standard cultivar Noire de Meched, among others, whereas four accessions known as Hedelfinger Riesenkirsche and four known as Grosse Schwarze Knorpelkirsche showed allelic differences at various loci. The genetic diversity of locally-grown cultivars worldwide might be currently underestimated. Several autochthonous Austrian sweet cherry germplasm accessions were genotyped for the first time and their genetic relationships analyzed and discussed. Interestingly, seven Austrian sweet cherry landraces were shown to be clearly genetically separated from international and modern varieties, indicating that Austrian germplasm could include valuable genetic resources for future breeding efforts.

Automated summary

This study genotyped 63 sweet cherry accessions, identifying 38 distinct allelic profiles and revealing significant genetic separation between Austrian sweet cherry landraces and international/modern varieties. The chosen SSR markers proved highly informative, with an average of 6.3 alleles per locus and above-average expected and observed heterozygosity levels, highlighting the potentially valuable genetic resources present in Austrian germplasm for future breeding efforts.