DETERMINATION OF RELATEDNESS AND GEOGRAPHICAL MOVEMENTS OF PISTACIA-VERA (PISTACHIO, ANACARDIACEAE) GERMPLASM BY RAPD ANALYSIS

The pistachio tree (Pistacia vera) has long been cultivated in south-central Asia and throughout the Mediterranean region of southern Europe, north Africa and the Middle East. We examined genetic diversity and patterns of relatedness among fifteen P. vera cultivars, representing germplasm originating from throughout this range, by using Random Amplified Polymorphic DNA (RAPD) markers. The resulting data were used to construct a similarity matrix and to perform a UPGMA cluster analysis. These analyses revealed two major clusters of P. vera germplasm: a Mediterranean cluster, which includes cultivars originating from the Mediterranean region of Europe, north Africa and the Middle East; and an Iranian-Caspian cluster, comprising germplasm originating from locations east of the Zagros mountains plus 'Peters: a cultivar selected as a seedling of unknown origin in the U.S.A. The data presented here, in combination with historical and geographical records, support the hypothesis that pistachio cultivation originated in or near the present natural range of the species and was spread by cultivation to the Mediterranean region of the Middle East. This more limited pool was the germplasm source for subsequent spread of pistachio by cultivation throughout the Mediterranean region.