Genetic variability in wild cardoon (Cynara cardunculus L. var. sylvestris) revealed by SSR markers and morphological traits

This research aims at characterizing germplasm diversity of wild cardoon (Cynara cardunculus var. sylvestris) for future breeding. Six populations were identified in in the north of Tunisia and 20 individuals per population were evaluated using UPOV descriptors, and a large variability was revealed between populations for their leaf characteristics. The genetic diversity was also assessed using SSR markers at seventeen loci, which were all polymorphic, and a high genetic variation was found out. A low differentiation (Fst = 0.104) coupled with a high level of gene flow (Nm = 2.25) were observed among populations. Only 10.4% of total genetic variability is shared between populations in comparison to 89.6% within population. Both morphological and molecular characterization showed that population grouping was not clearly related to their geographical distribution and this could be the result of the gene flow between regions. These results highlight a high level of genetic variation in Tunisian wild cardoon germplasm, which represents an interesting material to be conserved and exploited in breeding programs of artichoke.