Effects of nitrogen addition on growth and nutrients status of the Chinese traditional medicinal plant-Liriope Muscaria (Decne.) Bailey
Liriope muscari (Decne.) Bailey is a well-known traditional Chinese medicine used for treating cough and insomnia, and its main active component, saponin, has been studied as a candidate drug for cancer metastasis. Nitrogen deposition is also on the rise in China, presenting challenges to Liriope muscari (Decne.) culture. A simulated nitrogen deposition experiment using NH4NO3 was conducted in the Liriope muscari (Decne.) Bailey in the field. Five nitrogen treatments were used: CK (0kg N•hm-2a-1), N1(50 kg N•hm-2a-1), N2(100 kg N•hm-2a-1), N3(150 kg N•hm-2a-1) and N4(300 kg N•hm-2a-1). Our goals were to explore (1) how N addition affected growth of Liriope muscari (Decne.) ; (2) how N deposition affected the accumulation of saponin; and (3) how N addition affected the nutrient status of Liriope muscari (Decne.).
Tuber roots, which are the traditional medicinal parts, were promoted by the low and middle N treatments. N3 and N4 treatments increased the saponin content of tuber roots. The total saponin yield of tuber roots was highest in the N2 treatment. We suggest that the future increasing nitrogen deposition may decrease the yield of the tuber roots, while increasing the content of total saponin. The N/P and N/K ratios of tissues increased with increasing nitrogen input. The results of our study improve our understanding of the potential hazard of the increasing N input to Liriope muscari (Decne.) culture.