Genetic Assessment and Positioning of Algerian Barley Landraces with Respect to Landraces from the Middle East and Europe Using RAPD and SSR Markers.

Landraces are a critical genetic resource for resilience breeding, offering solutions to prepare agriculture for the challenges posed by climate change. Their efficient utilisation depends on understanding their history and genetic relationships. The current study investigates the phylogenetic relationships of barley landraces from Algeria, varieties from the Near and Middle East, traditional landraces, and modern cultivars from Europe. Using a core set of 33 varieties, including the wild ancestor Hordeum spontaneum from Armenia, genetic diversity was analysed with Random Amplified Polymorphic DNA (RAPD) and Simple Sequence Repeat (SSR) markers spanning all barley chromosomes. Based on the SSR-based phylogeny, the Algerian varieties are well clustered with those from the Near East, while distinct from the European varieties. The findings from RAPD markers partially support these results. Using exclusively traditional landraces, where a region of origin can be defined, the SSR markers are analysed separately for each chromosome individually, and the resulting clades are represented by the respective region of origin. This strategy resolves qualitative differences in geographic resolution, depending on the chromosome. While marker HvB23D (chromosome 4) separated the wild H. spontaneum from all domesticated genotypes, markers Bmag19 and Hv13GIII (chromosome 3) reveal four distinct geographic clusters (Maghreb, Near and Middle East, West Europe, Central Europe). These biogeographic patterns suggest a model, where divergence of domesticated barley due to human activity interacted with introgression of individual chromosomes from wild barley, yielding adaptive diversity. These biogeographic patterns suggest a model in which the divergence of domesticated barley, driven by human activity, interacts with the introgression of chromosomes from wild barley, resulting in the creation of adaptive genetic diversity. Our research advances our knowledge of barley landraces' functional genomics and highlights their potential in molecular breeding, particularly for developing resilient varieties suited to diverse environmental conditions.