Allocation and remobilisation of nitrogen in spring oilseed rape (Brassica napus L. cv. Mozart) as affected by N supply and elevated CO2
Allocation and remobilisation of nitrogen in spring oilseed rape (Brassica napus L. cv. Mozart) as affected by N supply and elevated CO2
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DOI：
10.1016/j.envexpbot.2012.03.015
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发表时间：
2012-11-01
影响因子：
5.7
通讯作者：
Fangmeier, A.
中科院分区：
文献类型：
--
作者：
Franzaring, J.;Gensheimer, G.;Fangmeier, A.
CO2浓度升高与植物资源经济性相互作用，但对氮素在植株不同部位之间的分配、碳氮比和氮素再动员的时间整合研究较少。本研究以春油菜为材料，研究了三种氮肥水平和两种CO2浓度(380和5501Mol(-1))下的氮素利用效率。氮素在播种、拔节和开花时分三次等量供应。其中一件礼物分别贴上了(NH4NO3)-N-15-N-15的标签。通过6次中期收获和1次最终收获，测定了植株根部、主茎、枝条、绿叶、衰老叶、角果壁和种子中的干质量、N浓度、C：N、N回收率和增量N-15特征。在环境CO2浓度下，接受75、150和225 kg ha(-1)N的处理中，可收获产品(种子)的氮含量分别占总氮量的50.7%、44.5%和41%。在CO2浓度升高的情况下，这些值分别下降到47.4%、34.5%和15%，使种子的NUE分别降低2%、33%和65%。在充分施肥的植株中，由于强大的分枝和结实减少，大部分氮素留在了侧茎中。然而，氮素再动员更多地受到不同氮素供应的影响，而不是受CO2增加的影响。在高有效氮条件下促进OSR的生长破坏了源：库的关系，因此CO2增加对茎和根生长的好处不能通过产量形成来实现。(C)2012爱思唯尔B.V.保留所有权利。
CO2 enrichment interacts with the resource economy of plants, but time-integrated studies on N partitioning between different plant parts, C:N ratios and N remobilisation are mostly lacking.The present study addressed the nitrogen use efficiency (NUE) in spring oilseed rape (OSR) grown at three N fertilisation levels and two CO2 concentrations (380 vs. 5501 mu mol mol(-1)). N was supplied in three equal gifts at sowing, stem elongation and flowering. One of these gifts was labelled with (NH4NO3)-N-15-N-15 respectively. Six intermediate harvests and a final harvest were performed to determine dry mass, N concentrations, C:N, N recovery and delta N-15 signatures in the plant fractions root, main stem, branches, green and senescent leaves, pod walls and seeds.While N concentrations were lower and C:N higher in green leaves under CO2 enrichment, more N remained in the root until the final harvest. Under ambient CO2 concentrations the harvestable product (seeds) contained 50.7%, 44.5% and 41% of the total N supplied in the treatments that received 75, 150 and 225 kg ha(-1) N, respectively. Under elevated CO2 these values decreased to 47.4%, 34.5% and 15% reducing the NUE of the seeds by 2%, 33% and 65%, respectively. In CO2 exposed amply fertilised plants much of the N remained in the side stems due to strong outbranching and reduced seed set. However, N remobilisation was more affected by the different N supply than by the CO2 enrichment.The boosted growth of OSR under high availability of N disrupted the source:sink relationships so that benefits from the CO2 enrichment on stem and root growth could not be realised by yield formation. (C) 2012 Elsevier B.V. All rights reserved.