Distinguishing features of Prunus humilis, P. japonica, P. pedunculata seeds and their adulterant based on DNA barcoding, morphological characterization, and chemical profiles.

ABSTRACT

Pruni Semen, the dried ripe seed of Prunus humilis, P. japonica, or P. pedunculata as recorded in the Chinese Pharmacopoeia, has been widely used in pharmaceutical and food industries. The adulteration of the marketed product with morphologically similar plants of the same genus has led to variable product quality and clinical effectiveness. This study systematically investigated the phylogenetic relationships, morphological traits, and chemical profiles of 37 Pruni Semen samples from planting bases, markets, and fields. DNA barcoding could successfully distinguish the genuine and counterfeit Pruni Semen, and the results indicated that there was almost no authentic Pruni Semen available in the market. The samples were divided into "big seed" (P. pedunculata and P. salicina seeds) and "small seed" (P. humilis, P. japonica, P. tomentosa, and P. avium seeds) categories based on morphology results. The notable discrepancy in the chemical characteristics of "big seed" and "small seed" was that "small seeds" were rich in flavonoids and low in amygdalin, whereas "big seeds" were the opposite. Furthermore, principal component analysis and clustered heatmap analysis verified the distinguishing features of "big seed" and "small seed" based on morphological and chemical characteristics. This study suggested that a combination of DNA barcoding and morphological and chemical characteristics can aid in the identification and quality evaluation of authentic and adulterated Pruni Semen. These findings may help standardize Pruni Semen available in the market and protect the rights and interests of customers.