Classification and Phylogenetic Relationship Identification of Weigela Plants Using DNA Barcoding Technology

Abstract

Abstract DNA barcoding technology is widely used in the classification and identification of plant germplasm. In this study, the chloroplast gene intergenic spacer trnC-petN and the nuclear gene intergenic spacer ITS2 were selected as DNA barcodes to identify 31 germplasm resources of the Weigela. The amplification and sequencing success rates for both primers were 100%. Based on the individual use of trnC-petN and ITS2, the accuracy was 66.76% and 75.56%, respectively. Both primers could accurately classify and identify most germplasm, but the accuracy for individual materials was relatively low. The combined analysis of trnC-petN and ITS2 divided the experimental materials of the Weigela into four groups: W. florida 'Red Prince' group, Weigela florida group, Weigela praecox group, and W. florida 'Linglong' group, with a high accuracy of 83.68%. The combined method, incorporating clustering results from individual markers, demonstrated higher accuracy than individual molecular markers, providing a better classification and identification of germplasm resources and their genetic relationships within the Weigela.