Adaptation, Cluster analysis, Physiological - genetics, Experiments, Genes, Genome, Genomes, Physiological - drug effects, Plant Roots - drug effects, Plant - genetics, Genetic Loci - genetics, Aluminum, Hordeum - drug effects, Hordeum - genetics, Linkage Disequilibrium - genetics, Hordeum - growth & development, Plant Roots - genetics, Aluminum - toxicity