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.

A set of 92 genetic resources of spring barley split into groups according to the areas of origin was studied in terms of grain malting quality. The following malting parameters were monitored in this study: nitrogen content in barley grain, malt extract, relative extract at 45 °C, Kolbach index, diastatic power, apparent final attenuation, friability, β-glucans in wort, haze of wort measured at the angles of 15° and 90°. In the studied set, the largest variability was found in the haze of wort (90°), the smallest in the apparent final attenuation. The optimal values of the extract content in the malt dry matter according to the malting quality index were only detected in the genotypes originating from Europe. The group of the genetic resources from South America and Australia, together with the genotypes from the Middle East and Africa, differed statistically significantly in the values of the Kolbach index from other groups. The two-row genotypes differed statistically significantly in the values of the malt extract content, relative extract at 45 °C, Kolbach index, diastatic power, friability and β-glucan content in wort. Although the European and non-European groups differed in a number of traits, the non-European groups also included genetic resources that in their malting parameters approached or equaled the European malting varieties (such as Psaknon). In this study, several significant correlations were found; the strongest correlations were between friability and malt extract (r = 0.85), friability and Kolbach index (r = 0.84).

In recent years, recurrent droughts have significantly affected spring barley production, reducing the quantity and quality of grain. This study aims to identify genotype-specific traits and the drought resilience of six different Hordeum vulgare L. (spring barley) genotypes, while also examining the potential of potassium application and fungal endophyte Serendipita indica inoculation to mitigate the negative effects of dry periods during the growing season. Field experiments were conducted over a three-year period from 2020 to 2022, measuring physiological, growth, and yield parameters. To get insight into the physiological state of the plants, we measured the soluble sugars content and the ratio of stable carbon isotopes in the flag leaf tissue, which reflects conditions during its formation. The dominant factors that influenced the measured parameters were the genotypes and seasons, as well as their interaction, rather than other experimental factors. The results showed that the Spitfire and Accordine varieties were the best performing in both the 2020 and 2021 seasons, as indicated by their yield. However, in the drier 2022 season, the yield of these two varieties decreased significantly (to 55% for Spitfire and to 69% for Accordine of their yield in 2021), while for the arid-region genotypes, it remained at the same level as the previous year. This study sheds light on the potential of various genotypes to withstand periods of drought and the effectiveness of using potassium application and S. indica inoculation as mitigation approaches.

Barley (Hordeum vulgare L.) is an important cereal, and powdery mildew caused by Blumeria hordei is a major disease of this crop. The most appropriate way to protect barley from the disease is to grow resistant varieties, and a method to achieve this is to exploit quantitative minor genes that confer sufficiently effective and long-lasting resistance. However, when searching for quantitative resistance, broken major genes can also play a role and might affect the infection of evaluated varieties, especially on small plots in experimental fields. Therefore, our present research focused on identifying accessions without major resistance genes. We tested 2804 genebank accessions of spring barley originating from 70 countries using nine isolates of the pathogen known to have a very wide spectrum of avirulence. In 143 accessions, no major resistance gene was found, and 304 accessions carried major genes Mla8 or MlCh, which cannot affect their resistance in the field because of the absence of corresponding avirulent pathotypes. These 447 accessions can therefore be preferably used to reveal and exploit targeted minor genes.