Landraces are considered a key element of agrobiodiversity because of their high variability and adaptation to local environmental conditions, but at the same time, they represent a breeding potential hidden in gene banks that has not yet been fully appreciated and utilized. Here, we present a genome-wide DArTseq analysis of the diversity of 116 spring barley landraces preserved in the collection of the Polish gene bank. Genetic analysis revealed considerable variation in this collection and several distinct groups related to the landraces’ country of origin and the grain type were identified. The genetic distinctness of hulless accessions may provide a basis for pro-quality breeding aimed at functional food production. However, the variable level of accession heterogeneity can be a significant obstacle. A solution to this problem is the establishment of special collections composed of pure lines that are accessible to breeders. Regions lacking genetic diversity have also been identified on 1H and 4H chromosomes. A small region of reduced heterogeneity was also present in the hulless forms in the vicinity of the nud gene that determines the hulless grain type. However, the SNPs present in this area may also be important in selection for traits related to grain weight and size because their QTLs were found there. This may support breeding of hulless forms of spring barley which may have applications in the production of high-quality foods with health-promoting values.

The extensive genetic diversity of crop landraces deposited in gene banks is an important part of future breeding programs. However, in order to exploit this potential, it is necessary both to preserve germplasm and to collect and share a wide range of data on its characteristics and evaluation. The main objective of the presented paper was to evaluate the diversity of spring barley landraces originating from Poland. Historical data from standard field evaluation of agronomic traits, genetic data obtained from Inter Simple Sequence Repeat (ISSR) analysis and grain morphometric data were used. The analysis showed that groups of hulled and hulls barley accessions were substantially separate. Genetic and grain morphological variation did not show any relationship with eco-geographical conditions in the place of origin. There was also no clear division into forms with two- and six-row ears. The combination of the results of various types of analyzes describing this collection makes us believe that its chances of being used in research and breeding will increase.

This study was undertaken to investigate the diversity and population structure of 83 spring barley (Hordeum vulgare L.) cultivars, which corresponded to 120 years of this crop’s breeding in Poland. The analysis was based on 11,655 DArTseq-derived SNPs evenly distributed across seven barley chromosomes. Five groups were assigned in the studied cultivars according to the period of their breeding. A decrease in observed heterozygosity within the groups was noted along with the progress in breeding, with a simultaneous increase in the inbreeding coefficient value. As a result of breeding, some of the unique allelic variation present in old cultivars was lost, but crosses with foreign materials also provided new alleles to the barley gene pool. It is important to mention that the above changes affected different chromosomes to varying degrees. The internal variability of the cultivars ranged from 0.011 to 0.236. Internal uniformity was lowest among the oldest cultivars, although some highly homogeneous ones were found among them. This is probably an effect of genetic drift or selection during their multiplications and regenerations in the period from breeding to the time of analysis. The population genetic structure of the studied group of cultivars appears to be quite complex. It was shown that their genetic makeup consists of as many as eleven distinct gene pools. The analysis also showed traces of directed selection on chromosomes 3H and 5H. Detailed data analysis confirmed the presence of duplicates for 11 cultivars. The performed research will allow both improvement of the management of barley genetic resources in the gene bank and the reuse of this rich and forgotten variability in breeding programs and research.