氮水平对雪菊幼苗中黄酮类化合物和矿质营养累积的影响

为探讨氮素水平对雪菊幼苗中黄酮类化合物和矿质营养累积的影响，以采自新疆皮山县克里阳乡的雪菊种子为供试材料，分别设置0（N1）、0.625（N2）、1.250（N3）、2.500（N4）、和5.000（N5）mmol·L^-1Ca（NO₃）₂ 共5个氮素水平处理雪菊幼苗，对雪菊的形态指标、矿质元素含量、黄酮类物质含量及关键酶活性进行测定分析。结果表明，随着氮素施用水平的增加，雪菊幼苗植株的碳/氮呈下降趋势，根、茎、叶中矿质元素含量发生显著变化。黄酮类化合物在较低氮素水平（N1、N2和N3处理）时含量较高，与苯丙氨酸解氨酶、肉桂酸4-羟化酶、4-香豆酸辅酶A连接酶、查尔酮合成酶活性密切相关。相关分析表明，雪菊植株内部矿质营养平衡对黄酮类化合物的积累有显著影响，特别是植株体内钾、钙、铜和铁元素的含量。综上所述，氮素的有效性及植株内部矿质营养的平衡可显著影响雪菊黄酮类物质的积累，为改善雪菊黄酮类化合物的积累及建立雪菊最佳种植策略提供了理论依据。

Effects of Nitrogen Levels on Flavonoids and Mineral Nutrient Accumulation in Coreopsis tinctoriaNutt.

In order to explore the effects of different nitrogen levels on the accumulation of flavonoids and mineral nutrients in C. tinctoria seedlings，C. tinctoria seeds collected from Keliyang Town，Pishan County，Xinjiang were used as the test materials. And the seedlings were treated by different oncentrations of Ca（NO₃）₂ including 0 （N1） and 0.625 （N2）， 1.250 （N3）， 2.500 （N4） and 5.000 mmol·L^-1 （N5）. The morphological traits of C. tinctoria seedlings were determined， and the contents of mineral elements and flavonoids， and the activities of key enzyme in root stem and leaf were analyzed. The results showed that the carbon/nitrogen decreased with the increase of nitrogen level， and the contents of mineral elements in plants changed. The accumulations of flavonoids were higher under lower nitrogen levels （N1，N2 and N3 treatments），which was closely related to activities of phenylalnine ammonialyase（PAL）， cinnamic acid 4-hydroxylase（C4H）， 4-coumaric acid CoA ligase（4CL）， chalcone synthase（CHS）. Correlation analysis showed that the balance of mineral elements had significant effect on the accumulation of flavonoids， especially changes in potassium， calcium， copper and iron elements. In conclusion， the availability of nitrogen and the balance of mineral elements in plant could significantly affect the accumulation of flavonoids in C. tinctoria， which provided theoretical basis for improving the accumulation of C. tinctoria flavonoids and establishing the best planting strategy of C. tinctoria.