Genetic diversity and phylogenetic relationships among Tunisian almond cultivars revealed by RAPD markers

One peach (Prunus persica) cultivar, 'Carnival', as well as 58 almond (Prunus dulcis Mill.) cultivars from the National Collection of Ettaous (Sfax, Tunisia), including local, Mediterranean, and North American cultivars. were examined using 12 random amplified polymorphic DNA (RAPD) markers. All the decamer primers revealed polymorphism. The number of polymorphic bands varied from six (with primers OP-A01, OP-A05, OP-A01 9, OP-B10, OP-B04. and OP-C10). to 13 (primer OP-B05). Cluster analysis using the unweighted pair group method with arithmetic means (UPGMA) showed that the level of similarity between almond and peach was 0.33, supporting the value of peach as a future source for genetic improvement of almond. Genetic diversity within the almond genotypes was interesting, as similarity values ranged from 0.45 - 0.94, probably because of the auto-incompatibility of the majority of cultivirs and the need for out-crossing. The resulting dendogram, at a similarity value of 0.53, divided the cultivars into six groups and an out-g roup with the cultivars 'Laurane' and 'Genco', as the most distant (similarity value S-D = 0.45). Clustering based on RAPD markers confirmed the power of this technique for cultivar identification and in revealing possible duplications. such as in the case of 'Fekhfekh' and 'Fekhfekh J.' which had a similarity value of approx. 0.9 and were probably the same. RAPD markers also identified mis-labelling. This was confirmed in 'Tuono Taranto' and 'Rachelle Taranto'. which appeared to be the same genotype (S-D - 0.94).