Effect Of Nitrogen Fertilization On Growth And Accumulation Of Flavonoids In Cyclocarya Paliurus

Cyclocarya paliurus is one of the unique monotypic plants and rare plants of key Protection in China,which has many functions,such as ornamental,timber,health care and medicine.And it has high potential value of development and utilization.Flavonoids,as one of the main medicinal components in leaves of Cyclocarya paliurus,have a variety of physiological functions,such as anti-hypertension,anticancer,hypoglycemia,anti-tumor,anti-oxidation,prevention and treatment of cardiovascular and cerebrovascular diseases,and they can effectively improve human immunity.Therefore,the study of flavonoids is an important basis for the study of development of medicinal value of Cyclocarya paliurus.by adjusting and controlling the fertilization conditions,the suitable fertilization conditions for growth of Cyclocarya paliurus and accumulation of flavonoids were discussed in order to provide a theoretical reference for the further development and utilization of Cyclocarya paliurus.In this experiment,the one-year-old Cyclocarya paliurus seedlings were used as research materials to investigate different nitrogen treatments(T1-10.0g/plant,T2-6.0g/plant,T3-3.4g/plant,T4-1.0g/plant,T5-（CK）differences in growth traits,photosynthetic index,chlorophyll content,plant tissue C and N content,and flavonoid content in yield and photosynthate of Cyclocarya paliurus seedlings,and exploring the optimal fertilization system to provide basis for rational application of N fertilizer.The main conclusions are as follows:（1）There was no significant difference in total height of T2-T5 of Cyclocarya paliurus seedlings grown under different nitrogen treatments,but it was significantly greater than that of T1.The diameter growth was almost the same as that of seedling height;the fast growth period of high net growth of seedlings was in July and August,the fast-growing period of net growth of ground diameters is from May to June.（2）The net photosynthetic rate of leaves of Cyclocarya paliurus was the highest of T2,which was 1.88μmolCO₂/m^-2s^-1.The chlorophyll content reached the highest of T3（8.33mg/g）,and the C and N contents in organs of Cyclocarya paliurus of all the treatments were the highest in the leaves.The C content highest was T4（42.26%）and the lowest was T1（40.83%）.The N content highest was T1（2.24%）,and the lowest was T5（1.27%）,and N content showed a tendency to increase with the increase of the amount of fertilizer.（3）T5（17.4 mg/g）was the highest in all treatments,T3（17.19 mg/g）was the second highest;and the contents of quercetin,isoquercitrin and kaempferol were the highest in T3.It was 0.23 mg/g,0.85 mg/g and 0.88 mg/g;the contents of total flavonoids,quercetin,isoquercitrin and kaempferol were the lowest in T1.（4）The highest yield of total flavonoids from Cyclocarya paliurus was T5（130.72mg/plant）and T3 was the second highest;the total output of the three flavonoids maximum of 10.51 mg/plant was T3.The yield was highest of T5 with quercetin and kaempferol,and the highest yield was in isoquercitrin was T3.The yield of total flavonoids in leaves of Cyclocarya paliurus leaves reached the maximum of 12.57 mg/plant was T5,and T4 was the second highest;The yields of quercetin,isoquercitrin and kaempferol were the highest with T3.The treatment with the lowest content of each measurement index was T1.