Th. Gladis Institute of Crop Science, K. Hammer University of Kassel, Germany The total number of plant species, which are cultivated as agricultural or horticultural crops, can be estimated to be close to 7,000 botanical species. Nevertheless, it is often stated that only 30 species "feed the world", because the major crops are made up by a very limited number of species. The latter is also the major reason that 6 million of accessions collected and conserved in gene banks belong to a very limited number of species compared to the total number of species, which contribute to food security. About half of all accessions maintained in collections ex situ are advanced cultivars or breeders' lines, while just over a third of them are made up by landraces, or old cultivars, and about 15 % are wild relatives of crop species, weedy plants or wild plants. Only a third of all accessions are characterized. There is obviously a gap in the collections regarding minor crops and underutilized species, in particular landraces and wild relatives of crops from the respective crops' centres of diversity and cultivation are underrepresented in gene banks. Therefore, the further exploration of minor and underutilized species, the collection of these genetic resources and the assessment of genetic diversity within and between landraces should have priority in gene banks' activities. At the same time it is necessary to develop better methods of characterization and evaluation of germplasm collections, to improve strategies for conservation and collection of germplasm, and to increase the utilization of plant genetic resources. The most effective methods for conservation of diversity for the respective plant groups considered, i.e. crops, their wild relatives, weeds and wild plants, are different. In some cases a combination of different strategies is the most effective way. The strategies include ex situ conservation (management of gene banks), conservation and management on farm (monitoring and protection of agro-ecosystems), in-situ-conservation (monitoring and protection of natural ecosystems). The most effective way of assessment of genetic diversity within a given taxon is also a combination of different methods, combining morphological, agronomic and molecular characterization of genetic diversity. The ongoing process of gene-erosion requires clear decisions for future strategies. To promote the work with animal genetic resources, a proposal is made to collect information about domesticated or at least reared animal species and to edit a manual in analogy to the dictionary of cultivated plants by Rudolf Mansfeld.