Intraspecific identification of some pomegranate (Punica granatum L.) genotypes based on DNA barcoding and morpho-biochemical characteristics

Key messageThe combination of nuclear and chloroplast barcode regions was very effective for distinguishing pomegranate genotypes.The simultaneous use of molecular, biochemical and morphological markers had a complementary function.Exclusion of similar genotypes regardless of their geographic region based on different markers helps to reduce the size of the collection, especially when building a core collection is the ultimate goal.Accurate identification of genotypes and their relationships is one of the major challenges in the study of plant taxonomy, especially at the subspecies level. For this purpose, molecular, biochemical, and morphological markers are commonly used in different plant species. In the present study, the sequences of three DNA barcode regions, including the ITS, trnl-F, and matK regions, and all their possible combinations were examined in 21 pomegranate (Punica granatum L.) accessions. In addition, 18 morphological and biochemical characteristics of the genotypes were measured simultaneously to confirm the distinctions. The results show that the combination of three barcode regions (ITS + trnl-F + matK) has the highest efficiency due to the highest number of variable sites as well as parsimony informative sites. Considering the phylogenetic trees obtained from the barcode regions and the morpho-biochemical traits, it can be seen that genotype 808 is clearly different from the other genotypes. Of the genotypes studied in this experiment, ten genotypes were classified into close groups based on their geographic origin in both the barcode and morpho-biochemical clusters. However, genotypes 709, 712, and 708, which were grown in different geographical areas, had similar characteristics, so they were grouped in close branches in both dendrograms. This suggests that the simultaneous use of molecular and morphological markers is essential for distinguishing pomegranate genotypes.