摘 要 ：本文采用盆栽试验研究了氮肥用量对药用菊花（药菊）生长及其药用品质的影响。结果表明，氮肥可促进植株生长、花芽分化和提前开花，提高菊花产量。当氮肥用量为0.5069 g/kg土时，药菊单株鲜花总产量最高，为542.01 g /株。菊花中绿原酸、总黄酮和可溶性糖的含量同氮肥用量成反比，高氮肥处理时上述成分最大下降幅度可分别达35.48%～45.26%、28.58%～35.58%和6.42%～9.51%。随着氮肥用量增加，药菊植株次生代谢关键酶苯丙氨酸解氨酶（PAL）活性和菊花中磷（P）、钾（K）、钙（Ca）元素含量大幅降低，而N/P、N/K和N/Ca比值和可溶性氨基酸含量升高。高氮处理因提高植株氮含量，降低PAL活性和可溶性糖含量，从而抑制植株绿原酸和黄酮等酚类物质合成而影响菊花的药用品质。试验还表明，当氮肥用量为0.4180～0.4598 g/kg土时，菊花中总黄酮和绿原酸的累积量最高。综合比较氮肥用量对菊花药材产量、外观品质、活性成分含量与累积量等因素的影响，建议菊花生育期内氮肥用量在0.30～0.40 g/kg土范围为适宜。
Abstract:Nitrogen (N) is an element of life and plays an important role on the quality of crops, vegetables and fruits. Recently, N has also been found to have an important effect on the secondary metabolism in plant, such as flavonoids and chlorogenic acid. The effects of different N application rates on growth, active ingredient accumulation and correlative physiological index of Chrysanthemum morifolium were studied by using a pot culture experiment. The results show that the uptake and accumulation of N element and the flower bud differentiation are promoted, and the contents of chlorophyll of C. morifolium and yields of the flowers are significantly increased under the applications of N nitrogen. When the N application rate is 0.5069 g/kg soil, the fresh flower yield is highest, and reaches to 542.01 g/plant. The P, K and Ca contents of C. morifolium and activity of PAL which is a key enzyme in the secondary metabolism of the plant are significantly decreased under the high N application rate. In fact, the contents of chlorogenic acid, total flavonoids and soluble sugar are significantly decreased with the increase of N application rate, which are declined by 35.48%–45.26%, 28.58%–35.58% and 6.42%–9.51%, respectively. With the high N application rate, it increases the N content, decreases the PAL activity and soluble sugar content of C.morifolium, and restrains the anabolism of chlorogenic acid and total flavonoids. Furthermore, the accumulations of total flavonoid, chlorogenic acid and soluble sugar of C. morifolium flower are highest when the N application rates are from 0.4180 to 0.4598 g/kg soil. The overall results suggested that the appropriate N application rate is 0.3–0.4 g/kg soil in production of C. morifolium.