ABSTRACT
Barley (Hordeum vulgare L.) has been cultivated over millennia, making it one of the oldest domesticated crops (Salamini et al. 2002). Ranking fourth in global cereal-crop production, it is used for animal feed, brewing malts, and human consumption (von Bothmer et al. 2003). Given barley’s long history as a crop involving migration and selection leading to adaptation to different environments and agroecology gradients, leading to a plethora of uses, it has the potential of being an excellent model for further elucidation of agricultural responses to changing and evolving climates (Dawson et al. 2015). Barley landraces are genetically heterogeneous populations comprising inbreeding lines and hybrid segregates generated by a low level of random outcrossing in each generation (Nevo 1992). The genetic structure of landraces may be considered as an evolutionary approach to survival and performance under arid and semiarid conditions (Schulze 1988). They are composed of several genotypes reported for both cultivated and wild barley (Brown 1978, 1979, Asfaw 1989). Natural selection accompanied by human selection during centuries of cultivation resulted in landraces that are genetically variable for qualitative and quantitative characters, have good adaptation to specific 88environmental conditions, and give dependable yields (Harlan 1992). Barley landraces have developed abundant patterns of variation and represent a largely untapped reservoir of useful genes for adaptation to biotic and abiotic stresses (Brush 1995, Tarekegn and Weibull 2011) to contribute to the improvement of modern cultivars (Hadjichristodoulou 1995).
