Population genetic structure analysis in endangered Hordeum vulgare landraces from Tunisia: Conservation strategies

Genetic markers have been employed in combination with morphological characters to identify patterns of population structure in 13 barley landrace populations from Tunisia. These endangered barley populations are grown by few local farmers in low-input farming systems. Based on 117 random amplified polymorphic DNA markers and 34 morphological traits, variance analyses indicated that most of the variation is partitioned within rather than between populations. Inbreeding index, gene flow values and cluster analysis revealed also significant differentiation between all populations. Gene flow decreased rapidly as the geographic distance increased. This may imply that seed exchange between farmers was limited to a regional scale. The lower correlation between the Euclidean distance matrices based on morphological and molecular data suggests that both data are comparably important to generate an unbiased picture of differentiation trends. Our findings support the required setting up of conservation strategies for Hordeum vulgare L. landraces from Tunisia.Key words: Barley landrace germplasm, RAPD, morphology, population differentiation analysis, conservation