Robusta (Coffea arabica L.) and Arabica (Coffea canephora A. Froehner) are the major agricultural commodities in Central Sulawesi, Indonesia, known for their unique flavor mostly influenced by local microclimates. The following study aimed to analyze the genetic diversity of 12 coffee genotypes procured from the Central Sulawesi Region using RAPD markers. Ten RAPD primers (OPA01, OPA02, OPA07, OPA16, OPD08, OPA13, OPG03, OPI07, OPY10, and OPX20) generated 103 DNA bands, with 102 as polymorphic. The DNA profiles’ binary data underwent analysis using Jaccard similarity coefficients and the unweighted pair group method with arithmetic mean (UPGMA) clustering. Genetic similarity ranged from 7% to 72%, with an average of 31%. Cluster analysis grouped the coffee genotypes into two main clusters unrelated to their taxonomic classifications, implying extensive genetic divergence potentially driven by local environmental conditions. Four non-conventional primers (OPA02, OPA13, OPA16, and OPD08) successfully amplified the DNA in several local genotypes. However, the local genotype Robusta Dombu did not amplify with any primer, pointing to possible mutation, highlighting its distinct genetic makeup. The results demonstrated a significant genetic diversity among the local coffee genotypes. Robusta Dombu, being a local coffee genotype, emerges as a potential candidate for developing climate-resilient and high-quality cultivars.

Keywords: Arabica, biodiversity, Coffea arabica, Coffea canephora, local adaptation, RAPD, Robusta

Key findings: The study showed the high genetic diversity in Coffea spp. genotypes by using RAPD markers. The phylogenetic clusters have not shown their belonging to two main ancestors, Robusta and Arabica, suggesting their highest variability during adaptation to local conditions.