Diversity and evolution of the Hordeum murinum polyploid complex in Algeria

Population diversity and evolutionary relationships in the Hordeum murinumL. polyploid complexwere explored in contrasted bioclimatic conditions from Algeria. A multidisciplinary approach based on morphological, cytogenetic, and molecular data was conducted on a large population sampling. Distributionof diploids(subsp. glaucum) and tetraploids (subsp. leporinum) revealed a strong correlation with a North–South aridity gradient. Most cytotypes exhibit regular meiosis with variable irregularities in some tetraploid populations. Morphological analyses indicate no differentiation among taxa but high variability correlated with bioclimatic parameters. Two and three different nuclear sequences (gene coding for an unspliced genomic protein kinase domain) were isolated in tetraploid and hexaploid cytotypes, respectively, among which one was identical with that found in the diploidsubsp. glaucum. The tetraploids (subsp. leporinum and subsp. murinum) do not exhibit additivity for 5S and 45S rDNA loci comparati...