Effects Of Combined Application Of Nitrogen And Potassium On The Growth And Secondary Metabolites Of Tinospora Sagittata

With the development of Tinospora sagittata（Oliv.）Gagnep’s medicinal value and the increase of market demand,the wild resources are decreasing day by day.However,the artificial cultivation of Tinospora sagittata is still in the initial stage.The experiment was conducted in Tuanbao Township,Lichuan City,Enshi prefecture,combining nitrogen and potassium with different levels（“3414”incomplete fertilization scheme）.The growth indexes（stem length,fresh and dry weight of overground and underground parts）,physiological indexes（content of soluble sugar,total nitrogen,total phosphorus,total potassium and organic matter）,the contents of effective components root tubers（columbin,palmatin,jatrorrhizine）,ash and alcohol extract of root tubers were determined under different fertilization treatments and growing years,so as to explore the relationship between the medicinal parts’yield,quality and the amount of N and K fertilizer applied,and to provide the theoretical basis and technical guidance for the artificial cultivation of Tinospora sagittata in Hubei province.The results are as follows:1.With the increase of growing years,the length of Tinospora sagittata was lengthening,but the rate of elongation was slow.The rate of Tinospora sagittata root drying ranged from 33.38%to 34.38%.2.With the increase of growing years,the dry weight of root tubers increased first and then decreased with the increasing of N and K fertilizer application.N₂P₂K₂treatment had the highest dry weight of root tubers in all stages,and the yield and quality could be considered being the best in the second growing years after transplantation,Autumn or Winter.3.The content of columbin for all the treatments were up to pharmacopoeia standard,and the effect of nitrogen fertilizer was greater than that of potassium fertilizer.4.The content of palmatin and jatrorrhizine in the root tubers increased first and then decreased with the increase of growing years,and the best harvest season was in the second years after transplantation,in Autumn or Winter.5.With the increase of growing years,the content of total N,total P,and total K all showed an upward trend.Proper N and K combined application was beneficial to the increase of P content in the root,stems and leaves of Tinospora sagittata.During the1 to 1.5 years old period,the content of soluble sugar in root,stems and leaves increased very fast,N₂P₂K₂ was the highest treatment which was up to 40.19%during the growing periods.The content of organic matter in root tubers was low in summer,high in autumn and winter,high in Summer and low in Autumn and Winter for stems and leaves.6.It is necessary to strengthen the root cleaning process to avoid soil adhesion.7.The chemical composition of the root tubers from different regions of China is similar,but the difference is mainly in these components’content.The result showed that the best yield and quality for 1 year old T.sagittate seedlings could be obtained in second years’Autumn and Winter after transplantation.The best fertilization treatment was N₂P₂K₂.