苹果砧木生长及吸收利用硝态氮和铵态氮特性比较

Growth Characteristics and Absorption,Distribution and Utilization of ^(15)NO_3^-N and^(15)NH_4^+-N Application for Five Apple Rootstocks

以一年生平邑甜茶(Malus hupehensis Rehd.)、八棱海棠(M.micromalus Makino)、楸子[M.prunifolia(Willd)Borkh.]、新疆野苹果[M.sievesii(Ledeb.)Roemer]、东北山荆子(M.baccata Borkh.)实生苗为试材,采用15NH4NO3和NH415NO3分别标记的方法,研究5种砧木的生长特性及其对NH4NO3中硝态氮和铵态氮的吸收、分配和利用特性。结果表明:幼苗生物量顺序为楸子>平邑甜茶>八棱海棠>新疆野苹果>东北山荆子;根系总表面积、总根长、根尖数均以楸子最大,东北山荆子最小。5种砧木对硝态氮和铵态氮的利用率顺序为楸子>新疆野苹果>平邑甜茶>八棱海棠>东北山荆子,5种砧木对硝态氮的利用率均高于铵态氮利用率,并且硝态氮利用率与根尖数呈显著正相关。5种砧木植株各器官从硝态氮中吸收分配到的15N量对该器官全氮量的贡献(Ndff)均高于从铵态氮中吸收分配到的;标记硝态氮时,楸子叶、茎和根的Ndff均最高,平邑甜茶最低;标记铵态氮时,东北山荆子叶、茎和根的Ndff均最高,新疆野苹果叶、楸子茎、平邑甜茶根最低。标记的硝态氮和铵态氮在器官中的分配均为叶>根>茎。

Five kinds of one-year-old apple rootstocks[Malus hupehensis Rehd.,M.micromalus Makino,M.prunifolia（Willd）Borkh.,M.sievesii（Ledeb.）Roemer and M.baccata Borkh.]were used to study the growth characteristics and the characteristics of absorption,distribution and utilization of labeled 15 NH4NO3 and NH4 15 NO3.The results were as follows：The biomass of five rootstocks from high to low were M.prunifolia（Willd）Borkh.M.hupehensis Rehd.M.micromalus MakinoM.sievesii（Ledeb.）RoemerM.baccata Borkh.The root surface area,total root length and root tips of M.prunifolia（Willd）Borkh.were the largest of the five,while M.baccata Borkh.were the least.The 15 NO3-N and 15 NH4 ＋-N utilization ratio of five rootstocks from high to low were M.prunifolia（Willd） Borkh.M.sievesii（Ledeb.）RoemerM.hupehensis Rehd.M.micromalus MakinoM.baccata Borkh.The1 5 NO3--N utilization ratio of the five kinds of rootstocks were higher than that of 15 NH4 ＋-N,and the1 5 NO3--N utilization ratio of the five kinds of rootstocks were significantly correlated with root tips.Ndff value of 15 NO3-N of the five kinds of rootstocks were higher than that of 15 NH4 ＋-N,and the value of leaves,shoots and roots of M.prunifolia（Willd）Borkh.with 15 NO3-N treatment was the highest,meanwhile value of M.hupehensis Rehd.with 15 NO3-N treatment was the lowest.The Ndff value of leaves,shoots and roots of M.baccata Borkh.with1 5 NH4 ＋-N treatment was the highest.The leaves of M.sievesi（iLedeb.）Roemer,the shoots of M.prunifolia（Willd）Borkh.,the roots of M.hupehensis Rehd.with 15 NH4 ＋-N treatments were the lowest.The two kinds of 15 N distribution ratio of leaves were the highest,while the shoots were the lowest.