Provenance variations in berberine content of Phellodendron amurense,a rare and endangered medicinal plant grown in Northeast China

Phellodendron amurense Rupr. produces berberine, a valuable ingredient in Chinese medicine. We examined how berberine content varied in different parts of the tree with age and geography in Northeast China. Berberine levels in root bark, trunk bark, and perennial branch bark, annual branches, and leaves were estimated by high-performance liquid chromatography. Root, trunk, and perennial branch barks had significantly higher berberine content than annual branches and leaves. Moreover, berberine content varied significantly with both longitude and latitude in samples of these three plant parts. The populations growing at low longitude and latitude contained significantly more berberine than those growing at high longitude and latitude. These results provide a scientific basis for the reasonable cultivation and efficient use of P. amurense.