氮素营养对苗期菘蓝叶中硝酸还原酶活性与矿质元素吸收的影响

采用正交试验设计,研究铵态氮、硝态氮和酰胺态氮3种氮素形态及其不同浓度配比对苗期菘蓝的单株干重、叶内的硝酸还原酶活性及矿质元素吸收的影响。结果显示:(1)影响苗期菘蓝单株干重的氮素形态依次为酰胺态氮>铵态氮>硝态氮。(2)不同氮素形态对叶片硝酸还原酶活性影响有差异,铵态氮影响最大,其次是硝态氮和酰胺态氮。(3)不同形态氮素配合施用后均能促进P、K、Ca、Mg、Cd、Mn、Cr、Sr 8种元素的吸收,但不利于Ni和Fe的吸收;元素吸收受铵态氮影响最大的矿质元素有K、Ba、Se、Ni、B、Si、Fe 7种元素,受硝态氮影响最大的元素有P、Cd、Ti、Al、Cu 5种元素,受酰胺态氮影响最大的元素有Na、Ca、Mg、Zn、Mo、Mn、Cr、Sr 8种元素。研究表明,不同形态氮素对苗期菘蓝吸收矿质元素的影响存在很大的差异,应注重酰胺态氮与无机的铵态氮、硝态氮的配合施用;适宜氮素形态及其配比能提高叶中硝酸还原酶的活性并促进矿质元素的吸收,从而有效地促进菘蓝的生长。

Effect of Nitrogen Nutrition on Nitrate Reductase Activity and Mineral Elements Absorption of Isatis indigotica Fort.at Seeding Stage

We studied the dry weight of individual plant,nitrate reductase activity and mineral elements absorption of leaves under three nitrogen forms and different concentration ratios by the use of orthogonal design,which were ammonium nitrogen,nitrate nitrogen and the amide nitrogen.The results showed that:(1)There were different dry weights by different nitrogen forms,which amide nitrogen was the most important nitrogen form,followed by ammonium and nitrate nitrogen;(2)There were different nitrate reductase activities in leaves by different nitrogen forms,which ammonium nitrogen was the most important nitrogen form,followed by nitrate and amide nitrogen;(3)The combined application of different nitrogen forms can promote absorption of phosphorus P,potassium K,calcium Ca,Mg,Cd,manganese Mn,chromium Cr,strontium Sr elements,but it is not beneficial to the absorption of nickel Ni,and iron Fe.Seven mineral elements,which were affected the most significantly by ammonium nitrogen,were K,Ba,Se,Ni,B,Si and Fe.Five elements,namely P,Cd,Ti,Al and Cu were affected the most significantly by nitrate nitrogen,and Na,Ca,Mg,Zn,Mo,Mn,Cr and Sr elements were affected by amide nitrogen.There were obviously differences among the effect of mineral elements absorption by different nitrogen forms.We should focus on the construction of the morphogenesis in the seeding stages of Isatis indigotica,and pay more attention to the combined application between the amide nitrogen and inorganic ammonium nitrogen,nitrate nitrogen.The appropriate nitrogen forms and ratios can increase nitrate reductase activity and promote minerals elements absorption,thereby promote the growth of I.indigotica.