Evaluation of Genetic Diversity among South Tunisia n Pomegranate ( Punica granatum L.) Accessions Using Fruit Traits and RAPD Markers

Abstract

Morphological and RAPD markers were used to investi gate the genetic diversity among 21 accessions of pomegranate originating from South Eastern Tunisia. Thirteen morphological traits were studied and results showe d significant differences for all morphological characters (P< 0.001). Clustering bas ed on fruit traits, using Ward’s method, divided the accessions into three main grou ps. In RAPD analysis, 6 out of 15 employed random primers showed good amplification a nd polymorphism on pomegranate samples with a total of 63 bands, of wh ich 56 were polymorphic. The lowest percentage of polymorphism (50%) was observed with TIBMBA-03 while the highest (50%) was observed with primer TIBMBB-03. According to Jaccard coefficient, the lowest (0.29) and highest (0.94) similarities were detected between genotypes. UPGMA clustering based on data from polymorphic RAPD band s resulted in three clusters at a similarity of 0.46. The Stress value for the nonmet ric multidimensional scaling plot was 0.071, showing an excellent representation of the d ata. The comparison between groupings based on the fruit traits and RAPD data d id not produce a significant correlation (r= -0.09). Using a stepwise linear reg ression, significant regressions were found between 13 morphological traits and 63 molecu lar markers revealing association between RAPD molecular markers and some traits. Keywords: Morphology, Random primers, Fruit traits, RAPD mar kers, Regression association.