Moroccan almond is a distinct gene pool as revealed by SSR

Genetic diversity of Moroccan almond and their relationship to foreign almond cultivars were studied. The genetic diversity of 68 accessions of local Moroccan almond [Prunus dulcis Mill.] and 32 foreign varieties from nine countries was analyzed using 16 microsatellite SSRs. Plant material is maintained at INRA Ain Taoujdate-Meknes experiment station. 234 alleles were detected, ranging between 89 and 252 bp. The number of alleles per locus varied, depending on the accession, from 4 to 24 with an average of 14.63 alleles per locus. The mean values of observed and expected heterozygosities, in this collection were respectively 0.62 and 0.79. All SSRs were polymorphic and able to distinguish between accessions analyzed. The dendrogram, based on UPGMA analysis using matrix generated by Dice similarity coefficient, grouped the accessions according to their geographical origin. Local accessions formed a separate group from foreign varieties. The genetic variability is quite large in this collection with the local material having evolved differently from the cultivated varieties.

► The SSR markers are polymorphic and able to distinguish between all accessions.
► The grouping of Moroccan genotypes is associated with their geographical origin.
► Moroccan almond trees shows a large variability expressed by the low coefficients of similarity.
► Moroccan almond trees have a different evolution than the foreign cultivars.