Pistachio (Pistacia vera L., family Anacardiaceae) is the only edible crop of 11 species in the genus Pistacia (Zohary 1952; Özbek and Ayfer 1958; Crane 1984). Piacista vera is the only species of the genus cultivated commercially and the rest of the species are mostly used as rootstocks for pistachio (Hormaza and Wünsch, 2011). It is referred to as the "green gold tree" due to its high economic value (Benmahioul 2012). The name pistachio derives from the old Persian word 'pista', which signifies pistachio in Zendor Avestan, the ancient Persian language.