%0 Journal Article %T Non-Authenticity of Spring Barley Genotypes Revealed in Gene Bank Accessions. %A Dreiseitl A %A Zavřelová M %J Plants (Basel) %V 11 %N 22 %D Nov 2022 11 %M 36432788 %F 4.658 %R 10.3390/plants11223059 %X Plant research and breeding depends on plant genotypes; therefore, genotype authenticity of accessions is the basic requirement for users of gene banks. Surprisingly, this extremely important topic is rarely reported in the scientific community. Non-authentic are accessions that are mislabelled and undesirable genotypes of heterogeneous accessions. In barley, we try to uncover both named problems on the basis of postulated major powdery mildew resistance genes. These are diverse, environmentally stable and their use is well documented and suitable for genotype characterization. In this contribution, we postulate resistance genes in 15 varieties represented by 157 derived lines of 32 accessions originating from seven foreign gene banks and compare these findings with previous results including those 15 identically labelled varieties from our domestic gene bank. We found that 37.5% of the gene bank accessions investigated herein were heterogeneous, and at least 20.0% were mislabelled. A large-scale molecular characterisation of varieties is now being carried out, and using authentic varieties must be one of the key requirements. Therefore, accessions of each variety from a minimum of three gene banks whose identity has been verified by reliable methods should be compared before starting new experiments. These will involve molecular varietal characterisation to serve as a foundation for future plant science research and effective crop improvement.