Microsatellite/SSR dataset: pomological and molecular characterization of pear cultivars (Pyrus communis) of the German Fruit Genebank

The German Fruit Genebank (https://www.deutsche-genbank-obst.de/) is a decentralized network dedicated to coordinating various germplasm collections across Germany. The aim is to conserve and utilize the genetic resources of native fruit species, i.e. pear. For effective conservation, the investigation of authenticity of the genetic resources is essential. Between 2019 and 2023, two projects were performed on the pear collections of the German Fruit Genebank to characterize the cultivars pomologically and molecularly. Eight partners of the pear network of the German Fruit Genebank participated in the projects. First, at least two experts of the Fruit Orchard Agency Schlaraffenburg (Schlaraffenburger gGmbH, https://schlaraffenburger.de/) identify the pear cultivars pomologically and define the authentic cultivar name per tree and accession. Second, 17 simple sequence repeat (SSR) markers and seven reference genotypes in recommendation of the European Cooperative Programme for Plant Genetic Resources (ECPGR; http://www.ecpgr.cgiar.org/) Malus/Pyrus working group were used for genetic fingerprinting. The molecular analysis, including experimental work and statistical analysis for grouping the genetic profiles based on similarity, was performed by Microsynth ecogenics GmbH (Balgach, Switzerland). The pomological and molecular data was compiled and resulted in 1,838 complete samples. The most important data features per sample are the cultivar name, the authenticity expressed by the trueness-to-type criterion, the molecular group and the genetic profile. Lastly, the individual samples were collated into unique, synthetic genetic profiles per distinguished pear cultivars with the help of a computer program and manual review. Mutations and sports of cultivars cannot be distinguished molecularly, but only pomologically and are grouped within the origin cultivar as they carry the same molecular group but different cultivar names. In total, 420 pear cultivars with corresponding genetic fingerprints were identified and evaluated for their authenticity as part of the German Fruit Genebank as presented in the published dataset. Additionally, the genetic fingerprints were aligned to international datasets to assign the Pyrus UNiQue genotype code (PUNQ). To evaluate the certainty of the synthetic genetic profiles, a quality ratio was calculated per genetic locus and on average where the consensus across samples is reflected.