Cultivated apple (Malus × domestica Borkh.) is a major crop of economic importance, both globally and regionally. It is currently, and was also in the past, the main commercial fruit in the northern European countries. In Finland, apple trees are grown on the frontier of their northern growing limits. Because of these limits, growing an apple tree from a seed was discovered in practice to be the most appropriate method to get trees that bear fruit for people in the north. This created a unique culturally and genetically rich native germplasm to meet the various needs of apple growers and consumers from the late 1800s to the mid-1900s. The preservation, study and use of this genetic heritage falls within the mandate of the Finnish National Genetic Resources Program. The first national apple clonal collection for germplasm preservation was reorganized from the collections of apple breeders. The need to evaluate the accessions, both in this collection and possible missing ones, to meet the program strategy lead us to evaluate the Finnish apple heritage that is still available in situ in gardens. In this article we use multiple-approach methodologies and datasets to gain well-described, proof-rich samples for the trueness-to-type analysis of old heirloom apple varieties. The approach includes a combination of socio-historic, pomological and genotyping methods and datasets that are all valued as equally important. The main finding was that in addition to the pomological, molecular and genetic evaluation of ex situ apple collections, an extensive historical data and socio-economic conditions research are essential to perform good characterization of accessions. After implementing the results in re-creating the Finnish national apple germplasm collection, the number of Finnish local varieties was more than doubled from 38 accessions to 97.

European wild apple (Malus sylvestris L.) is the only Malus wild species native to Europe which is a relative of cultivated apples (Malus × domestica Borkh.). It grows on forests’ edges, farmland hedges, and marginal sites; by living in those scattered meta-populations, it is exposed to genetic erosion in relation to hybridization and habitat degradation. In Finland, it grows at the northern edge of its distribution in Europe and is considered as a near-threatened taxon requiring urgent conservation. In order to evaluate the molecular genetic diversity of M. sylvestris, five populations including 43 trees were analyzed using 15 microsatellite markers. Additionally, a similar number of samples from cultivated apples, which are common to the same region, was included in order to estimate gene diversity gaps and give an insight into putative hybridization. European wild apple in Finland proved to be populationally structured, and seems not to be threatened by introgression events from its cultivated relative. They were all separated into different clusters, except for one individual. However, urgent conservation is indeed needed, especially due to the very low total number of trees (four) in some of the analyzed populations. These populations should be restored in order to enable permanent access to the wild relatives’ diversity, as they might be a critical source of gene variants for future needs.

Potato onion (Allium cepa var. aggregatum G. Don) remained the most widely grown onion type in Finland up to the 1950’s, after which the more productive cultivars of common onion replaced this vegetatively propagated onion type. The Finnish accessions have been maintained in two national plant genetic resources (PGR) collections since 1990’s but new samples have been obtained still later. In this research, we analysed the genetic diversity of potato onions and shallots, grown in home gardens and in PGR collection, and compared the uniformity of the two PGR collections. One hundred ten onion samples were analysed using eight microsatellite loci, which amplified 83 alleles in total. There was a large number of genetically different samples, forming four major groups in the dendrogram. The results show that there is still a lot of genetic diversity among the Finnish potato onions, even though they are propagated vegetatively. The rich diversity in the samples obtained from citizens reflects a valuable source of genetic resources maintained by home gardeners. The national collection has been updated on the basis of the results. To ensure the preservation of the rich onion heritage, efforts are needed to increase the availability of potato onion to home gardeners and commercial growers.