Effects of light quality on growth and icariin flavonoid content of Epimedium pseudowushanense under different light intensity / 中国中药杂志

In this study, the growth index including plant height, compound leaf area, specific leaf area, leaf water content, number of branches, and leaf biomass per plant and the icariin flavonoids such as epimedin A, epimedin B, epimedin C and icariin of Epimedium pseudowushanense were determined on 30 d and 60 d under light intensity(18.2±2.5) μmol·m~(-2)·s~(-1)(L1) and(90.9 ±2.5) μmol·m~(-2)·s~(-1)(L2), and white light as control, red light, blue light and yellow light were used as three light quality treatments, to study the effect of light quality on the growth and flavonoids accumulation of E. pseudowushanense. The E. pseudowushanense was sui-table for growth under L1 light intensity, the blue light treatment significantly reduced the leaf area, but had little effect on the stem height, the red light treatment and the yellow light treatment had no obvious effect on the stem height and leaf area, but the yellow light treatment significantly increased the germination of new branches, and had a sustained promoting effect, and the biomass was significantly higher than the white light treatment at 60 d. The content of icariin flavonoids in red light, blue light and yellow light treatment was higher than that in white light treatment at 30 d and 60 d under L1 light intensity, while yellow light treatment promoted the synthesis of icariin flavonoids to the largest extent, which was 1.8 and 1.9 times of white light treatment(30 d and 60 d).Under L2 light intensity, the effect of strong light on promoting stem germination became the main factor, while the yellow light treatment showed no significant effect on promoting stem germination, and the red light treatment exhibited a significant effect on reducing leaf area. Icariin flavonoids under red light, blue light and yellow light treatment were all lower than that under white light treatment, that is, the effect of white light treatment on the synthesis of icariin flavonoids is better than red light, blue light and yellow light treatment. When the time of strong light treatment was longer, the degradation range of icariin flavonoids in other light treatment appeared, while red light treatment promotes the synthesis of icariin flavonoids. Therefore, the influence of light quality on E. pseudowushanense is quite different under different light intensity, no matter from growth index or flavonoid content index. The results support that the biomass and icariin flavonoid content can be increased by providing appropriate red and yellow light.

Effects of nitrogen on yields and flavonoids contents of Epimedium pseudowushanense in hydroponic conditions / 中国中药杂志

Nitrogen nutrition divided into concentrations and forms for Epimedium pseudowushanense was studied under hydroponic conditions. There were 7 nitrogen concentrations treatments（N0-N6）which nitrogen concentration was 0, 2.5, 5.0, 7.5, 10.0, 13.0 mmol•L⁻¹, respectively, and 5 nitrogen forms and proportions treatments (T1-T5) which NO3-N/NH4-N was 5∶0, 4∶1, 2.5∶2.5, 1∶4, 0∶5 respectively, the total nitrogen applied was 5 mmol•L⁻¹. The results showed that along with the increase of nitrogen concentration, biomass (dry weight) and leaf dry weight increased, which in N5 treatment was 29%, 23% higher than those in N0 and 36%, 23% higher than those in N4 respectively, but not significantly different from N6 treatment. Roots and stem dry weights did not change significantly. Pn and the contents of photosynthetic pigments were higher in N3-N5 treatments. Epimedin A, B, C, icariin and total flavonoids contents were the lowest in N3 treatment, suddenly increase in N4 treatment and only a little change between N4-N6 treatments. N5 treatment with the highest epimedin C content was 131% higher than N3 treatment with the lowest epimedin C content (P<0.05). While in the nitrogen forms and proportions treatments, biomass, leaf and stem dry weights were the highest in T3 treatment and lower in T1 and T5 treatments, without significance between T1 and T5 treatments. These indicators in T3 treatment were more than 30% higher than those in T1 treatment. The impact of nitrogen concentrations was greater than nitrogen forms on flavonoids. epmedin C content was the highest in T1 treatment, only 5%-8% higher than that in T2-T5 treatments (no significance between 4 treatments). Epimedin A, B, icariin and total flavonoids contents were higher in T1 treatment, the lowest in T2 treatment, those in T1 treatment was 41%, 62% and 27% higher than T2 treatment respectively (P<0.05). In a conclusion, E. pseudowushanense is a high nitrogen tolerant plant, 10.0 mmol•L⁻¹ was the boundary point between growing general to well and the optimal nitrogen concentration for it was 10.0-13.0 mmol•L⁻¹. Besides, it prefers to grow in NO-3 plus NH+4 and the optimal proportion was 2.5∶2.5.