Fig. 2

Genetic structure of C. canephora individuals evaluated with 4,021 DArTseq SNP markers. Scatter plots from the DAPC analysis carried out with 34 C. canephora accessions. a Discriminant axes 1 and 2 (left) and 3 and 4 (right) representing the five groups (inertia ellipses) determined by the DAPC. Group 1 encloses cultivated individuals from Congo and Uganda, known to belong to the Robusta Congo-Uganda group; Group 2 represents the accessions previously described into the Nana group, from Cameroon and the Central African Republic; Group 3 is equivalent to the Conilon group, with cultivated individuals from the Ivory Coast; Group 4 is made up of only wild and cultivated Guinean accessions collected in the Ivory Coast; and finally, Group 5 is composed of wild individuals from the Central African Republic belonging to the Robusta Congo-Central Africa group. b First discriminant axis deciphering the genetic relationships between individuals from the two sub-groups of group 2. For each DAPC analysis (a and b), the Bayesian information criterion (BIC) used to determine the optimal k number of clusters (blue dot), the percentage of cumulative variance for the retained PCA eigenvectors (black dots), and the F-statistic of the between/within group variance ratio for the discriminant functions (colored bars) are also exposed below each DAPC plot