红富士苹果枝条下垂处理对^(15)N尿素吸收、分配及利用的影响

Effects of Branch Drooping on Characteristics of Absorption,Distribution and Utilization of ^(15)N-urea Application for Malus domestica Borkh.'Red Fuji'/Malus hupehensis

以7年生红富士苹果(Malus domestica Borkh.‘RedFuji’)/平邑甜茶(Malushupehensis)为试材,研究枝条下垂处理对春季土施15N尿素的吸收、分配与利用的影响。结果表明:枝条下垂处理植株的根系从肥料中吸收分配到的15N量对根系全氮量的贡献率(Ndff)均低于对照,其中细根在多个物候期差异显著,而粗根在果实膨大期后差异显著;中短梢及中短梢叶的Ndff差异不显著;处理果实及长梢和长梢叶的Ndff在果实采收前均显著低于对照;处理植株多年生器官的Ndff在果实采收后显著高于对照。从15N分配率看,处理植株的中短梢一直显著高于对照,果实在膨大期后显著高于对照;长梢在果实采收前显著低于对照。处理植株的15N利用率低于对照,在果实膨大期后差异显著,两者植株15N利用率在果实采收后分别为21.083%和26.495%。

Seven-year-old apple trees（Malus domestica Borkh.＇Red Fuji＇）/Malus hupehensis were used in the present study to explore the effects of branch drooping on characteristics of absorption,distribution and utilization of 15N-urea through soil application in spring.Ndff value of roots in treated plant was obviously lower than that of control.Ndff value of fine roots was obviously different during multiple phenophases,while significant variance in Ndff value of coarse roots was found after fruit rapid-swelling stage.There was no regular pattern between Ndff value of leaves in short and middle shoots between the treatment and the control.Meanwhile,Ndff value of fruits,long shoot and leaves in long shoot with treatment was obviously lower than that of control before fruits were harvested,while Ndff value of perennial organs in treated plant was obviously higher than that of control after fruits were harvested.The 15N distribution ratio to short and middle shoots of treated plant was significantly higher than that of control,while difference of distribution to fruit between the treatment and the control was significant only after fruit rapid-swelling stage.Moreover,the distribution ratio to long shoot of treated plant was obviously lower than that of control before fruits were harvested.The 15N utilization ratio of treated plant was lower than that of control,and the significant difference was found after fruit rapid-swelling stage,the 15N utilization ratio of treated plant and control were 21.083% and 26.495% respectively.