Abstract
DNA barcoding relies on short and standardized gene regions to identify species. The agricultural
and horticultural applications of barcoding such as for marketplace regulation and
copyright protection remain poorly explored. This study examines the effectiveness of the
standard plant barcode markers (matK and rbcL) for the identification of plant species in private
and public nurseries in northern Egypt. These two markers were sequenced from 225
specimens of 161 species and 62 plant families of horticultural importance. The sequence
recovery was similar for rbcL (96.4%) and matK (84%), but the number of specimens assigned
correctly to the respective genera and species was lower for rbcL (75% and 29%) than matK
(85% and 40%). The combination of rbcL and matK brought the number of correct generic and
species assignments to 83.4% and 40%, respectively. Individually, the efficiency of both markers
varied among different plant families; for example, all palm specimens (Arecaceae) were
correctly assigned to species while only one individual of Asteraceae was correctly assigned
to species. Further, barcodes reliably assigned ornamental horticultural and medicinal plants
correctly to genus while they showed a lower or no success in assigning these plants to species
and cultivars. For future, we recommend the combination of a complementary barcode
(e.g. ITS or trnH-psbA) with rbcL + matK to increase the performance of taxa identification. By
aiding species identification of horticultural crops and ornamental palms, the analysis of the
barcode regions will have large impact on horticultural industry.