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作 者 ：李洪娜,季萌萌,彭玲,姜翰,葛顺峰,姜远茂

期 刊 ：植物营养与肥料学报 2014年 20卷 6期 页码：1460-1467

关键词：中间砧；埋土深度；苹果幼树；内源激素；氮素利用；

Keywords:interstock, buried depth, young apple tree, hormone, nitrogen utilization,

摘 要 ：【目的】苹果矮化密植集约化栽培已成为国内外现代苹果生产发展的主流和方向。应用矮化中间砧是当前我国果树生产上采用的主要致矮手段,但矮化中间砧苹果存在氮素吸收利用率低、 树势弱、 易衰老等问题,目前我国对于矮化中间砧的栽培标准尚不统一,生产上大都采用的中间砧埋深1/2的措施也缺乏一定的理论依据。因此,研究中间砧不同埋土深度对苹果幼树内源激素和氮素利用的影响,以期为确定SH6中间砧埋土的最适深度提供理论依据。【方法】利用¹⁵N同位素示踪技术,以两年生宫藤富士/SH6/平邑甜茶(Borkh cv. Fuji/SH6/M.hupehensis Rehd)为试材,于春梢萌芽前,设置3个埋土深度,其中T1为中间砧全埋,T2为中间砧埋深1/2,T3为中间砧全露,同时每棵施0.5 g ¹⁵N-尿素,5次重复。于春梢旺长期、 春梢停长期,采用酶联免疫法测定茎尖和细根的激素含量;植株停止生长时,整株解析,称量各部分鲜重、 干重,测定植株全氮及其¹⁵ N 丰度。【结果】中间砧埋土深度与植株生长关系密切,株高、 茎粗、 鲜重、 细根生物量均以全埋(T1)最高,全露(T3)最低,且两者差异显著。中间砧不同埋土深度影响植株内源激素含量,不同处理间存在差异,新梢旺长期和新梢停长期茎尖、 新梢中赤霉素(GA)和生长素(IAA)含量均表现为T1>T2>T3,而脱落酸(ABA)的含量则相反; 新梢停长期,T2处理茎尖的玉米素核苷(ZR)/赤霉素(GA)比值比T1和T3处理分别升高了8.53%、 6.06%;各时期茎尖和细根的ABA/GA和 ABA/IAA比值均为T3>T2>T1;新梢旺长期,T1、 T2和T3处理茎尖(GA+ZR+IAA)/ABA比值分别为1.66、 0.83和0.71。植株全氮、 ¹⁵N吸收量、 氮肥利用率均以T1处理最大,T2处理次之,T3最小;同一器官不同处理间Ndff%值也存在差异,T3处理显著高于其他处理。【结论】SH6中间砧埋深1/2处理的生长促进型激素GA和IAA的含量以及(GA+ZR+IAA)/ABA比值均降低,并且与花芽分化有关的ZR/GA比值明显升高。中间砧埋深1/2处理既能调节植株体内激素平衡,起到矮化效果,又能促进根系对氮的吸收利用、 提早花芽分化。因此生产上SH6苹果中间砧以埋深1/2的效果最好。

Abstract:【Objectives】Intensive cultivation of dwarfed apple rootstocks is becoming a direction of efficient cultivation for apple at home and abroad. The application of dwarfed interstocks is the main routinein dwarfed apple cultivation, and because of the lack of standard cultivation technique and theoretical basis in 1/2 buried of interstocks, dwarfed apple trees are in low nitrogen utilization, weak tree vigor and fast senescence. Therefore, the effectof different buried depths of interstocks on nitrogen absorption and utilization of dwarfed interstocks and the endogenous hormonewas studied, aiming to provide a scientific basis on appropriate buried depth of the interstocks in apple production. 【Methods】Two-year-old Fuji/SH6/malus hupehensis Rehd trees were selected as materials for studying the nitrogen absorption and utilization by using the ¹⁵N isotope tracer technique. The buried depths were interstocks entirely buried(T1), interstocks 1/2 buried(T2)and interstocks entirely bared(T3)respectively. There were 5 replicates, and 0.5 g ¹⁵N-urea was applied respectively. At the vigorous growing stage and stop growing stage, the hormones in stem tips and fine roots were measured using the method of enzyme-linked immunoassay (ELISA). The whole plants were sampled when the shoot stop growing, and the fresh weight and dry weight of each part were weighed, and the plant total nitrogen and ¹⁵ N abundance were detemined.【Results】The results show that the plant growth of interstocks is significantly related with the buried depth, and the height and diameter of plant, total fresh weight and fine root biomass of the T1 treatment are the highest, while those of the T3 treatment are the lowest. The content of endogenous hormonevaries with the buried depth of interstocks, and the contents of gibberellin (GA) and auxin(IAA) of different buried depths are in order of T1>T2>T3 at the vigorous growing stage and the stop growing stage of the new shoot, while the abscisic acid (ABA) contents show an adverse tendency. The ratio of trans-zeatin-riboside(ZR)/gibberellin(GA) in shoot tips of T2 is 8.53% and 6.06% more than those of T1 and T3 at the new shoot stop growing period. The ratios of ABA/GA and ratios of ABA/IAA of stem tips and fine roots during the period are in order of T3 > T2 > T1. The values of (GA+ZR+IAA)/ABA of T1, T2 and T3 in shoot tips are 1.66, 0.83 and 0.71 at the new shoot growing stage. The plant total nitrogen, ¹⁵N uptake and fertilizer utilization rate of T1 treatment are the highest, those of the T2 treatment are in the second place and those of the T3 treatment are the lowest. The Ndff values also varied among treatments, and the value of the T3 treatment is significantly higher than those of the others.【Conclusions】The interstocks 1/2 buried of SH6 reduces the content of growth promoting hormone(IAA and GA)and(GA+ZR+IAA)/ABA ratio, and increases the ZR/GA ratio which relates to flower bud differentiation significantly. The interstocks buried 1/2 treatment can balance the hormone in plant, dwarf the tree, promote the bud differentiation and then increase the absorption and utilization of nitrogen, therefore, the interstocks buried 1/2 of SH6 apple trees present the best in production.

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