供氮水平和稳定性对苹果矮化砧M9T337幼苗生长及^(15)N吸收、利用的影响  

Effects of nitrogen supply levels and stability on growth and ^(15)N absorption and utilization of M9T337 dwarf rootstocks seedlings

作　　者：彭玲[1] 田歌[1] 于波[1] 何流[1] 葛顺峰[1] 姜远茂[1] PENG Ling;TIAN Ge;YU Bo;HE Liu;GE Shun-feng;JIANG Yuan-mao(College of Horticulture Science and Engineering, Shandong Agricultural University/State Key Laboratory of Crop Biology Tai ＂an, Shandong 271018, China)

机构地区：[1]山东农业大学园艺科学与工程学院/作物生物学国家重点实验室,山东泰安271018

出　　处：《植物营养与肥料学报》2018年第2期461-470,共10页Journal of Plant Nutrition and Fertilizers

基　　金：国家重点研发计划项目(2016YFD0201100);国家自然科学基金项目(31501713);国家现代农业产业技术体系建设资金项目(CARS-27)资助

摘　　要：【目的】研究氮素供应水平及稳定性对苹果幼苗生长及氮素吸收特性的影响,可以深化理解苹果对氮素供应的响应生理机制,为果树生产科学供氮提供理论依据。【方法】以M9T337矮化自根砧苹果幼苗为供试材料进行水培试验。设置营养液中NO_3~–-N浓度不足、适宜、过量三个水平(NO_3~–浓度为依次为0.5、5、25mmol/L)。苹果幼苗先在三个浓度的培养液中培养10 d,在此基础上,增设培养液NO_3~–-N浓度从不足变过量处理(N1)、从过量变不足处理(N2)、持续适宜供氮处理(N3)、持续不足处理(N4)及持续过量处理(N5),苹果幼苗继续生长10天,总培养时间为20天。测定了苹果幼苗生物量、根系形态和NO_3~–流量大小,根系和叶片硝酸还原酶活性和硝态氮含量,以及^(15)N吸收利用。【结果】供试苹果幼苗处理20 d后,以稳定适量供氮处理N3的生物量最大,持续不足供氮处理N4最小,N1处理地上部干重增幅最高;N3处理根系总长、总表面积最大,根尖数最多,N4处理次之,N5处理最小。N2处理两次取样间隔内增幅最大,其根系总长及总表面积分别增加了31.5%和34.9%;NO_3~–-N浓度变换1 d后,N1处理根系NO_3~–吸收流量最大,为46.37 pmol/(cm2·s),和N3处理间无显著差异。NO_3~–-N浓度变换10 d后,N3处理根系NO_3~–吸收流量显著高于其他处理,N5处理变为外排,N1处理较NO_3~–-N浓度变换1 d时降低了62.0%;各器官Ndff值、植株总氮量及^(15)N吸收量均以N3处理最高,N4处理最低,N1处理增幅最大;处理第11 d,N5处理根系和叶片硝态氮含量最大,和N3处理间无显著差异。处理第20 d,N3处理叶片硝态氮含量比N5处理低13.42%,差异达显著水平;N5处理叶片硝酸还原酶活性在处理12 d后显著低于N3处理,处理20 d时,叶片硝酸还原酶活性大小为N3>N1>N5>N2>N4。【结论】供氮不足限制幼苗氮素吸收,供氮过量导致氮素同化及根系生长受抑,均不利于苹果[Objectives] Studying the effects of the stability and levels of nitrogen supply on the growth and nitrogen absorption characteristics of apple seedlings will help further understanding the physiological mechanism of apple seedlings, which will provide theoretical basis for nitrogen fertilization in apple orchards.[Methods] Hydroponic culture method was used with M9T337 dwarf rootstocks seedlings as tested materials. NO3--N concentrations of deficiency, appropriate and excess （NO3--N 0.5, 5 and 25 mmol/L in turn） were setup in the cultural solution. The seedlings were cultured in the three solutions for 10 days, then the treatments were transferred as the following five ones：NO3--N concentration varied from deficit to excess treatment （N1）, from excess to deficit treatment （N2）, keeping appropriate （N3）, keeping deficiency （N4） and keeping excess （N5）. The 10 days seedlings were continually cultured for another 10 days in above treatments. The plant dry matter, root morphology and root NO3- uptake flux, contents of NO3- and nitrate reductase enzyme activity in the roots and leaves, and the plant total N content and 15N absorption were measured.[Results] The highest plant dry matter was obtained in the N3 treatment and the least in the N4 treatment. The biggest increase of shoot dry matter was found in the N1 treatment at the 20th day after the treatment. The most significant effect on root length, root surface area and quantity of tips of seedlings was in the N3 treatment, followed by the N4 treatment, and least in the N5 treatment. The biggest increase appeared in the N2 treatment, with the root length and root surface increment of 31.5% and 34.9% respectively between the two sampling intervals. One day after the change in NO3--N concentration, the highest NO3- uptake flux was found in the N1 treatment, which was 46.37 pmol/（cm2·s）, and no significant difference with that in N3 treatment. On the 10th day after NO3--N concentration change, the root NO3- uptake flux in the N3 treatme

关 键 词：苹果 生长 变化浓度 氮吸收 氮流量 

分 类 号：S661.1[农业科学—果树学]