Fig. 4

a Two-dimensional plot of principal coordinates analysis of 124 date palm genotypes that represent for nine populations. b Estimation of population using ΔK = mean (|L”(K)|) / sd(L(K)) with cluster number (K) ranging from 1 to 10 and K = 3 is the optimal K value based on Evanno et al. (2005) method. c Results of STRUCTURE analysis based on microsatellite data and estimation of genetic structure of the nine populations using K = 3. Each population is represented by a vertical bar and separated by a black line, partitioned into coloured segments representing the proportion of the individual’s genome in the K clusters