Mediterranean basin Ficus carica L.: from genetic diversity and structure to authentication of a Protected Designation of Origin cultivar using microsatellite markers

Abstract

The selected germplasm of Ficus carica established in a gene bank collection will be useful for conservation and management and important for fig tree breeding programs. Advancement in plant breeding is assisted by accurate information on genetic diversity and structure. A collection of ninety fig tree (Ficus carica L.) cultivars originating from the Mediterranean basin and conserved in an ex situ gene bank collection was genotyped using seven microsatellite markers. A total of 91 alleles were detected presenting an average of 13 alleles per locus. The gene bank fig tree collection preserved a high level of genetic diversity. The mean expected and observed heterozygosities over the seven single locus microsatellites averaged 0.747 and 0.784, respectively. The total value of the probability of identity was 2 × 10−6. The 90 fig tree accessions formed four clusters in the unweighted pair group method using arithmetic averages (UPGMA) dendrogram, although the clustering did not indicate any clear division among the fig tree accessions based on their geographical origin. Moreover, the 90 fig tree accessions could be divided into two clusters based on STRUCTURE analysis. Additionally, microsatellites coupled with high-resolution melting analysis enabled both the distinction, identification and authentication of the ‘Kymis’ fig tree Protected Designation of Origin cultivar and its products. In conclusion, results presented here are significant for the management of gene bank collections, breeding programs and authentication of fig tree cultivars.