Cultivated strawberries (Fragaria L.), raspberries (Rubus L.), and several other berries belong to the Rosaceae. Fragaria as well as Rubus are comprised of a highly heterozygous series with a range of ploidy levels. Blackcurrants, red currants and gooseberry belong to the Saxifragaceae, whereas blueberry (Vaccinium L.) crops belong to the Ericaceae. Domestication, breeding, and the transition from small-scale production to intensive production in specialized farms have resulted in a reduction of both morphological and genetic diversity. Therefore, retaining the variability available today to limit the decrease of the genetic base is important. Most of the temperate fruit species are genetically heterozygous and vegetatively propagated. In Europe, collections of berry genetic resources are maintained in the field as active plantations where the accessions are available for characterization, evaluation, and distribution. Backups for the plant material are needed to provide security in case of a disease or an environmental disaster. A long-term coordinated work with extending collaborative actions of berry genetic resources on the European level is necessary. In March 2019, the new Berries Working group was established under the umbrella of the European Cooperative Programme for Plant Genetic Resources (http://www.ecpgr.cgiar.org/ working-groups/berries/). At present, 85 members from 22 European countries have accepted collaboration within this working group. The main goal of the working group is to coordinate the activities between the national collections based on a continuous long-term network cooperation. This includes different activities for harmonizing and enhancement of management of existing ex situ collections of berry genetic resources. The European Search Catalogue for Plant Genetic Resources will be used for the documentation.

The preservation of fruit genetic resources has a long-lasting tradition in Germany. It dates back to the early decades of the 20th century. Ever since, a multitude of cultivars of different fruit crop species is preserved in federal and state governmental institutions as well as in communities and towns, non-governmental organizations, and by private individuals. The German Fruit Genebank has been established as a decentralized network with the aim to coordinate the preservation in the different germplasm collections in Germany to minimize the risk of losing cultivars of fruit species and therefore to maintain a part of the cultural heritage. Currently, the German Fruit Genebank is composed of six species-specific networks consisting of 48 different collections. In addition to the cultivar collections, the Fruit genebank of the Institute of Breeding Research on Fruit Crops, Dresden-Pillnitz includes collections of crop wild relatives of the fruit species important for fruit production in Central Europe. Special emphasis is given on the genera Malus and Fragaria representing 46 and 22 taxa respectively. These accessions are valued for their diverse alleles but also for their specific genotypes. Different cryopreservation protocols were elaborated. For Fragaria a protocol combining vitrification with cold acclimation and for Malus a protocol based on dormant winter buds can now be realistically used to build up a Cryo bank as a duplicate collection. Based on the results provided, a combination of the traditional ex situ conservation approach and cryopreservation approach has a great potential to improve conservation of fruit genetic resources contributing to the National Program for Genetic Resources of Agricultural and Horticultural Crops in Germany.

Premature leaf fall disease is caused by the hemibiotrophic ascomycete Diplocarpon mali (Y. Harada & Sawamura 1974) (anamorph Marssonina coronaria). Breeding for disease resistance and development of resistant cultivars could help to defeat the disease in the future. The first step in resistance breeding is to assess Malus genetic resources for resistance to M. coronaria. The aim was to proof a detached leaf assay as phenotyping procedure. Disease assessment was performed after 14 days post inoculation (dpi). Different symptoms obtained from the inoculated genotypes indicate a high level of susceptibility in Malus cultivars. In contrast, M. baccata accession MAL0419 was tolerant to M. coronaria. Future experiments will show whether the tolerance of M. baccata accession MAL0419 is inherited and if the genotype is a possible donor for resistance breeding toward M. coronaria.

The angular leaf spot disease caused by Xanthomonas fragariae is an important plant disease with major impact for the strawberry nursery industry. Currently there is no plant protection product available for controlling the disease effectively. Planting of resistant cultivars seems to be promising, but all commercially used cultivars are susceptible and no donor with a high level of resistance has yet been found. Therefore, a total of 145 genotypes from the Fruit Gene-bank Dresden (Germany) were evaluated for resistance to X. fragariae by artificial inoculation. Six genotypes were classified as partly resistant, out of which only two (US4808 and US4809) are octoploid. Fragaria vesca f. alba, Fragaria nilgerrensis 'Yunnan', F. vesca 'Illa Martin' and F. moschata 'Bauwens' were also classified as partially resistant, but they are only of limited use for breeding because of their variable ploidy level. Fully resistant genotypes could not be detected. The systemic dispersal of the bacteria in strawberry plants was investigated after inoculation of leaves with X. fragariae strain XF3.9. C and the GFP-tagged strain XF3.9. C-(pKAN). The systemic spread was evaluated after 3, 7, 14 and 28 days post-inoculation (dpi) by nested PCR and fluorescence microscopy. After 3 dpi, X. fragariae could be found in all tissues tested including the inoculated leaf, its petiole, the rhizome, the heart bud up to the youngest fully expanded leaf and its petiole. The systemic spread was also detectable in partially resistant genotypes.

The grey mould disease caused by Botrytis cinerea leads to substantial economic losses in strawberry production all over the world. Control of the disease requires an extensive amount of fungicide that is applied in varying complexes because the pathogen easily develops resistance against the active compounds. Planting of resistant cultivars seems to be a promising alternative for fruit growers, but there are currently no cultivars available combining resistance to B. cinerea with attractive horticultural traits. Breeding of new cultivars requires the effective identification of resistant strawberry genotypes; therefore the current study was aimed at the evaluation of strawberry genetic resources under controlled conditions by establishing an artificial inoculation assay. The method presented in this study is an artificial inoculation of ripe fruits with a defined spore suspension under laboratory conditions. The results show that this assay is fast and simple and leads to reproducible results that correlate with field observations. Over 3 years a total of 107 strawberry genotypes of the German National Fruit Genebank at the JKI in Dresden‐Pillnitz were evaluated. Five partly resistant genotypes, cultivars Diana, Joerica and Kimberly, and Fragaria virginiana ‘Wildmare Creek’ and F. vesca subsp. bracteata, were identified with mean disease levels of <20% at 6 days post‐inoculation. The obtained results are discussed with regard to future breeding activities.

Strawberry domestication has resulted in a reduction of both morphological and genetic diversity with modern cultivars. Therefore, it seems to be important keeping all the variability available today in order to limit the decrease of the genetic basis of small berries genetic resources and enriched genetic pool for future breeding. One of the tools for preservation genetic resources is maintaining collections that represent all spectrum of variability. Creation of centralized, well characterized and harmonized European strawberry collection was the aim of European project "Small berries genetic resources" (GENBERRY) co-funded by DG AGRI. However, success of maintaining sufficiently large and representative collection depends on many factors, among other sanitary status of the accessions. Methods preventing the breakage of collections caused by pests and diseases, including management growing system to maintain sanitary status of strawberry collections in open field, greenhouse and in vitro conditions were collected and developed by different partners of GENBERRY project.

In Germany, all activities of fruit genetic resources management are based on the German National Program for Genetic Resources of Agricultural and Horticultural Plants. Three areas of actions, like ex situ conservation in field collections and building safety back-ups, characterization of the material, and utilization of genetic resources in breeding are described for fruit species collected at Dresden-Pillnitz.

Organic strawberry production suffers from high yield losses caused by numerous fungal and bacterial diseases. Two of the most important diseases are the grey mould disease caused by Botrytis cinerea Pers. (teleomorph Botryotinia fuckeliana), and the bacterial angular leaf spot disease caused by Xanthomonas fragariae (Kennedy & King). Beside cultivation methods and organic plant protection measures, the development of resistant cultivars seems to be the most promising strategy in order to improve the productivity in organic strawberry cultivation. Therefore, we established resistance tests to determine resistant and susceptible strawberry cultivars and breeding selections. In a first run, 40 different cultivars and selections were tested for their susceptibility towards B. cinerea by artificial inoculation of fruits and leaves and evaluation of the disease symptoms. Plants of 40 cultivars were tested for susceptibility to X. fragariae by artificial inoculation in the greenhouse. In a diallel crossing approach, 12 commonly cultivated strawberry cultivars have been crossed reciprocally and propagated in a field trial. Important characteristics of the progeny such as ripening time, yield, morphological traits and occurrence of diseases have been evaluated for a period of two consecutive years and lead to the determination of general (GCA) and specific (SCA) combining abilities. Together with the results of the resistance tests we identified a set of genotypes that show resistant characteristics towards B. cinerea and might be suitable for use in organic cultivation systems. Furthermore, they can be used for targeted breeding experiments in the future.

The National German Strawberry Genebank includes 369 cultivars and the active field collection in Dresden-Pillnitz also contains 317 Fragaria wild species accessions. The conservation strategy requires the application of several methods for safety duplication. First, in vitro cold storage was developed and adapted. The average storage duration at 4 C for a range of strawberry cultivars was 22 months using five chamber bags as the storage container and Jungnickel medium without plant growth regulators or vitamins. The wild species could be stored for 6 to 9 months. After cryopreservation by PVS2 vitrification, recovery of the cultivars averaged 61% and of the wild species 30%. A calculation of the effort required to establish and maintain a safety duplication of the whole collection demonstrated that the application of in vitro cold storage is too labour intensive to be maintained. The development of an effective method for cryopreservation is required for cost effective long-term storage.

Dry matter of fruits may be an essential parameter in fruit processing. Especially in the very energy-intensive freeze drying process, high values of dry matter in the freshly harvested fruits contribute to a lower requirement of energy and to lower costs. In sour cherry often processed by freeze drying, little is known about the dry matter content of various cultivars. For that reason, the parameter was evaluated in 33 cultivars during the years 2005-2007. Dependent on cultivar and year, values between 10.7% ('Montmorency' in 2007) and 28.2% ('Stevnsbaer Viki' in 2006) could be observed. In the average over the years, 'Montmorency' was characterized by the lowest dry matter content (13.1%). Maximum values were very different for all the other cultivars 'Stevnsbaer Viki' reaching 23.9% and 'Stevnsbaer Birgitte' 24.1%. In spite of clear variations between the years, cultivars differed significantly. The results show that cultivars with a high dry matter content are available for using in freeze drying. The content of dry matter was highly correlated to the content of soluble solids (correlation coefficient 0.91). Therefore the investigation of soluble solids can be used for rapid testing of dry matter of a wide range of genotypes.

Flavonoids are a large family of polyphenolic compounds with manifold functions in plants including pathogen defence. Present in a wide range of vegetables and fruits, flavonoids form an integral part of the human diet and confer multiple health benefits. Modifying flavonoid biosynthesis in fruit crops, such as apple, offers the opportunity to increase plant resistance against pathogens and the health benefit potential of the fruit. Both overexpression and RNAi-based suppression strategies were used to modify flavonoid biosynthesis in apple. Introducing the maize Lc transcription factor gene, responsible for controlling the expression of structural genes of the flavonoid biosynthetic pathway in maize, into Malus domestica Borkh. cv. 'Holsteiner Cox' resulted in increased mRNA levels for most of the structural genes of the flavonoid pathway. Lc transgenic plants accumulated higher levels of the anthocyanin idaein, the flavan-3-ols epicatechin, catechin, and some distinct dimeric proanthocyanidins. In a second approach, the consequences of RNAi silencing of the genes for anthocyanidin synthase (ANS) and UDPgalactose: flavonoid 3-O-galactosyltransferase (FGT) gene to induce a shift towards flavan-3-ols were examined. Preliminary results obtained from transgenic plants of the cv. 'Holsteiner Cox' and of the red-leaved type TNR 31-35 (a descendent from Malus sieversii var. sieversii f. niedzwetzkyana (Dieck)) revealed that suppression of ANS or FGT resulted in increased amounts of flavan-3-ols and flavonols. In the red leaved type TNR 31-35, anthocyanin accumulation decreased after ANS silencing.

Resistance breeding in apple has a long tradition at the Institute of Fruit Breeding now Julius Kuehn-institute in Dresden-Pillnitz. The breeding was aimed at the production of multiple resistance cultivars to allow a more sustainable and environmentally friendly production of apple. In the last decades a series of resistant cultivars (Re®-cultivars) bred in Dresden-Pillnitz has been released, 'Recolor' and 'Rekarda' in 2006. The main topic in the resistance breeding programme was scab resistance and the donor of scab resistance in most cultivars was Malus x floribunda 821. Due to the development of strains that are able to overcome resistance genes inherited by M. x floribunda 821 and due to the fact that single resistance genes can be broken easily, pyramiding of resistance genes is necessary. Besides scab, fire blight and powdery mildew are the main disease for which a pyramiding of genes is aspired in Pillnitz. Biotechnical approaches are necessary for the early detection of pyramided resistance genes in breeding clones. This paper will give an overview of the resistance breeding of apple in Pillnitz and the methods used.