作 者 ：康晓育 常 聪 孙协平 张 欣 谢银鹏 马锋旺 邹养军
期 刊 ：植物营养与肥料学报 2014年 20卷 4期 页码：965-973
Keywords:nitrogen stress, drought, apple seedling,
摘 要 ：【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料，采用砂培方法，研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响，分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异，以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理： 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平，分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/L NO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG），并且相对应处理下秦冠的以上指标均高于富士；正常供水下，缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加，富士提高了2.05%，秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）； 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎，磷元素则是根＞叶＞茎；光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著，富士处理之间差异不显著；秦冠的PNUE和NUE明显高于富士，在低氮正常水（DZ）处理下，秦冠氮肥利用率比富士高42.07%，在低氮干旱（DG）处理下高64.14%；低氮胁迫下富士和秦冠的NUE显著提高，并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量，同等水肥条件下，秦冠生长优于富士；水分亏缺会减少叶片对氮的吸收，干旱条件下适度增施氮肥，可提高果树的抗旱能力；低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士，表现出较强的抗低氮干旱胁迫的能力。
Abstract:【Objectives】The effects of nitrogen stress and drought on the growth, photosynthetic parameters, nitrogen(N), phosphorus(P), potassium(K) absorption in different parts of apple seedlings and the nitrogen use efficiency were analyzed. 【Methods】Two cultivars of one\|year\|old apple seedlings(Fuji and Qinguan grafted Malus hupehensis Rehd.) were used in sandy pot culture experiment.Four treatments with two levels of nitrogen and water were designed. Normal nitrogen and normal water(ZZ), low nitrogen and normal water(DZ), normal nitrogen and droughts(ZG), low nitrogen and droughts(DG). Normal nitrogen(6 mmol/L NO-3\|N) and low nitrogen(0.3 mmol/L NO-3-N); normal water(keep the relative water content as 80%-85%) and drought(keep the relative water content as 60%-65%). For both Fuji and Qinguan the biomass of stems and leaves, plant height and stem diameter, photosynthetic rate, stomatal conductance and transpiration rate showed the highest results under normal water and N supply supply(ZZ), then descanted in order of low N and normal water(DZ), normal N and drought(ZG) and N and drought stress(DG) treatments. All the indices determined in Qinguan were higher than in Fuji under the same treatments. In normal water supply, the root/shoot ratios of Fuji and Qinguan with N stress treatment were 2.05% and 22.40% higher than normal N supply in Fuji and Qinguan respectively. The N, P, K contents in Fuji and Qinguan seedlings decreased with treatment of ZZ, DZ, ZG and DG. N and K contents in leaves were higher than in roots and stems, P content were increasing in order of root， leaf and stem. The net photosynthetic efficiency of unit leaf area(PNUE) and N efficiency were significantly different between treatments in Qinguan，not significant in Fuji. Under N stress and normal water supply, the PNUE and N efficiency in Qinguan were higher than in Fuji, the N efficiency in Qinguan was 42.07% higher than Fuji under N stress and normal water supply, and 64.14% higher under N stress and drought treatment. The N efficiencies were increased significantly in the two cultivars with the higher increase in Qinguan than in Fuji under N stress treatment. 【Conclusion】 Water stress will reduce the absorption of nitrogen by leaf, increase of nitrogen application could improve drought tolerance of fruit trees. The growth index, photosynthetic index and N efficiency of Qinguan were superior to Fuji, and Qinguan showed more tolerant than the low nitrogen supply.
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