The First Exploration of the Genetic Richness of an Ancient Algerian Citrus Collection Using Molecular Markers

Abstract

This study presents a genetic characterization and population structure analysis of an ancient Algerian collection of Citrus fruits, dating back to the colonial period of the early 1900s. Genetic diversity was assessed using eight Simple Sequence Repeat (SSR) markers, with the objective of accurately identifying their varieties and elucidating their genetic relationships, particularly in the absence of passport data and documented origins. A total of 96 accessions were analyzed. Instances of homonymy, synonymy, and labeling errors were detected. Observed heterozygosity ranged from 0.451 to 0.715, with a mean value of 0.54, while polymorphic information content (PIC) values varied between 0.225 (CCSM18) and 0.635 (TAA41). The genetic relationship patterns among the different Citrus groups were consistent with their botanical classification. Structureanalysis suggested differentiation between the pomelo–orange cluster and the lemon group, as well as between the mandarin and clementine groups. These results suggest thatAlgerian Citrus germplasm may represent a valuable and relatively underexplored resource for breeding programs, highlighting the importance of its proper characterization and conservation to prevent genetic erosion.