Nitrogen fertilization affects the growth performance, betaine and polysaccharide concentrations of Lycium barbarum

Lycium barbarum, also known as Goji, is a popular medicinal plant in the traditional Chinese medicine. The present study aimed to examine the effects of nitrogen (N) fertilization on the growth performance, betaine and polysaccharide concentrations in different plant parts of L. barbarum. L. barbarum seedlings were subjected to organic (Org 1: 15gNpot-1; Org 2: 30gNpot-1) and chemical (Chem 1: 2.5gNpot-1; Chem 2: 5gNpot-1) N fertilizer treatments, followed by collecting the plant materials for chemical analysis. Results showed that the yield and uptake of N in plants of Org 2 (high organic fertilizer) treatment were the highest. Although plants of Chem 2 (high chemical fertilizer) treatment demonstrated to contain the highest N concentration, its yield in biomass was the lowest. A decrease in soluble sugar, polysaccharide and betaine concentrations was noted with increasing application of chemical N fertilizer. However, an increase in the organic N fertilizer favors the betaine synthesis. Taken together, these results conclude that L. barbarum responded differently to the type of fertilizers, with the increase application of N fertilizer lead to a decrease in polysaccharide concentration whilst enhancing the betaine synthesis. © 2010 Elsevier B.V.