AFLP analysis sheds light on distribution of two Salix species and their hybrid along a natural gradient

Amplified fragment length polymorphism (AFLP) analysis of 26 trees of three Salix taxa: Salix alba L. (White Willow), S. fragilis L. (Crack Willow) and their hybrid S. x rubens Schrank, across an example of their habitat range in south-west Germany, supported the distribution previously determined using morphological characterization. UPGMA and principal coordinates analysis of the AFLP data revealed three distinct clusters corresponding to the three taxa. In addition, AFLP analysis on individuals which were difficult to identify morphologically revealed that they were either the hybrid S. nr rubens or S. fragilis. Four specimens of S. fragilis were indistinguishable with three primer combinations suggesting they are members of one clone.