Genetic diversity of fig (Ficus carica L.) genotypes grown in Southern Italy revealed by the use of SSR markers

The genetic variability among 181 fig (Ficus carica L.) accessions found in small farms located in Campania, Basilicata, Apulia, Calabria and Sicily was investigated analysing the polymorphism of 18 simple sequence repeat (SSR) markers. The SSR analysis revealed a large genetic diversity among accessions. A total of 117 alleles were detected with a mean of 6.5 locus-1. The average expected (He) and observed heterozygosity (Ho) were 0.56 and 0.66, respectively. The mean polymorphic information content (PIC) was 0.51, suggesting a significant molecular diversity among the fig accessions taken into consideration. The UPGMA cluster analysis discriminated 174 genotypes and allowed to find 8 groups of identity. The genotype 'Bianca di agosto' was an "outgroup". This study showed groups of fig accessions matching with their geographic or cultivation area, but also many genotypes, especially from Campania, with uneven distribution. The research evidenced the richness of the available fig genetic resources in Southern Italy, resolved cases of synonymies and homonymies and helped to characterize fig accessions, an important preliminary work for establishing core collections.