Analysis of genetic diversity in Croatian fig (Ficus carica L.) germplasm using SSR markers

In Croatia, the common fig (Ficus carica L.) is one of the oldest cultivated fruit trees, commonly present in family orchards. Significant efforts have been made lately to collect national genetic resources to ensure their long-term conservation in ex situ collections, and thus, their sustainable management. In Croatia there are two ex situ fig germplasm collections, with 22 accessions officially registered in the Croatian Plant Genetic Resources Database. The aim of this study was to characterize the collections and to assess the genetic diversity of collected fig germplasm. A set of 90 accessions from Croatian collections and six reference samples from a Slovenian database were genotyped using five SSR markers. A total of 24 alleles were detected, with the observed number of alleles per locus ranging from three (FCUP-016-6) to seven (FCUP-038-6) with an average of 4.8 alleles per locus. The UPGMA clustering analysis discriminated 31 genotypes and revealed five groups of accessions. In total, 77 duplicated accessions, 11 new genotypes, and 20 cases of homonymy and synonymy have been determined. The genetic relationships among Croatian traditional fig cultivars have been assessed. Results obtained in this study can be used for germplasm conservation, breeding programs, nursery production improvement, and for optimizing the national strategy for the management of fig genetic resources.