Genetic diversity and molecular evolution of the internal transcribed spacer (ITSs) of nuclear ribosomal DNA in the Tunisian fig cultivars (Ficus carica L.; Moracea)

► The internal transcribed spacers (ITS1 and ITS2) are sequenced and analysed for 31 fig cultivars. ► Results suggest the occurrence of haplotypic and nucleotide diversity with a large variation level of ribosomal DNA. ► Molecular evolution analysis confirmed an explicit rejection of the null hypothesis. ► The ITS region is not evolved under a strictly neutral model of molecular evolution. ► A scenario of positive selection and recent expansion of Ficus carica across Tunisia seems to be retained.