AFLP analysis of <i>Lactuca saligna</i> germplasm collections from four European and three Middle Eastern countries

Abstract

Lactuca saligna L. (least lettuce, willow-leaf lettuce) is widely distributed around the Mediterranean basin and extends to the Caucasus and temperate Europe; its extra-European distribution covers the Middle East. The aim of this study was to estimate the level of molecular variation and the extent of genetic differentiation of L. saligna in accessions collected in natural and semi-natural habitats in Europe and the Middle East. In sum, 67 accessions of L. saligna, originating in four European countries (Czech Republic, France, Italy, Portugal) and three Middle Eastern countries (Israel, Jordan, Turkey), were compared on the basis of AFLP polymorphism. AFLP analysis of the accessions revealed 415 (84.7%) polymorphic fragments out of 490 fragments amplified by means of seven primer pair combinations. The number of bands produced by individual primer pair combinations ranged from 44 to 101. The UPGMA dendrogram generated from Jaccard's similarity matrix showed a similar genetic background of accessions from the Middle East (Turkey, Israel, Jordan), which were quite distinct from the group of accessions from the European part of the Mediterranean basin (Italy, France, Portugal). Surprisingly, two accessions, one from the Czech Republic (central Europe) and one from Israel, proved genetically wholly separate from all other accessions of L. saligna and are themselves wholly separate. Accessions originating in various eco-geographical conditions were found to differ significantly in their genetic polymorphism.