Identification of traits to improve the nitrogen-use efficiency of wheat genotypes
Identification of traits to improve the nitrogen-use efficiency of wheat genotypes
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DOI：
10.1016/j.fcr.2011.05.010
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发表时间：
2011-08-14
影响因子：
5.8
通讯作者：
Foulkes, M. J.
中科院分区：
文献类型：
--
作者：
Gaju, O.;Allard, V.;Foulkes, M. J.
氮（N）肥料代表种植者的显著成本，并且还可能通过与反硝化相关的硝酸盐浸出和N2 O（温室气体）排放而具有环境影响。本研究的目的是分析冬小麦氮素利用效率（单位土壤和肥料有效氮的籽粒干物质产量; NUE）的遗传变异，并确定改良NUE的性状，以供育种应用。14个英国和法国品种和两个法国先进的育种系进行了测试，在2年/四个网站的网络，包括在法国和英国的不同地点。在开花期和收获期进行了详细的生长分析，包括DM和N分配的实验。旗叶或整个叶冠层的衰老从开花至完全冠层衰老每3-4天从视觉评分评估。使用五参数单分子逻辑方程将衰老评分与热时间拟合，从而估计开花后衰老的开始时间和速率。在每个试验中，在低N（LN）下，籽粒产量降低，平均减少2.2 t ha（-1）（29%）。显着的N ×基因型水平的相互作用，观察NUE。收获时作物平均吸氮量从高氮（HN）条件下的227 kg N ha（-1）减少到LN条件下的109 kg N ha（-1），而氮利用效率（收获时单位作物吸氮量的谷物DM产量; NUtE）从34.0 kg DM kg（-1）N增加到52.1 kg DM kg（-1）N。LN下NUE的总体遗传变异主要与NUtE的差异有关，而不是氮吸收效率（收获时作物对每单位土壤和肥料中氮的吸收; NUpE）。然而，在一个网站也有一个积极的相关性NUPE和NUE在LN在这两年。此外，在2年/4个地点的网络中，NUpE的Nx基因型效应部分解释了籽粒产量和NUE的Nx基因型效应。平均在16个基因型，衰老的发病时间解释了86%的NUtE之间的网站季节N处理组合的变化。在HN下，NutE基因型之间衰老开始的线性回归不显著，但在LN下，在四个位点中的三个位点上衰老开始的线性回归显著，解释了NutE基因型之间32-70%的表型变异。基因型之间的衰老发病率呈负相关，与开花期地上N再动员到LN下的粮食的效率。因此，延缓花后衰老可能是低氮条件下小麦籽粒产量提高的一个重要性状。(C)2011 Elsevier B. V.保留所有权利。
Nitrogen (N) fertilizer represents a significant cost for the grower and may also have environmental impacts through nitrate leaching and N2O (a greenhouse gas) emissions associated with denitrification. The objectives of this study were to analyze the genetic variability in N-use efficiency (grain dry matter (DM) yield per unit N available from soil and fertilizer; NUE) in winter wheat and identify traits for improved NUE for application in breeding. Fourteen UK and French cultivars and two French advanced breeding lines were tested in a 2 year/four site network comprising different locations in France and in the UK. Detailed growth analysis was conducted at anthesis and harvest in experiments including DM and N partitioning. Senescence of either the flag leaf or the whole leaf canopy was assessed from a visual score every 3-4 days from anthesis to complete canopy senescence. The senescence score was fitted against thermal time using a five parameters monomolecular-logistic equation allowing the estimation of the timing of the onset and the rate of post-anthesis senescence. In each experiment, grain yield was reduced under low N (LN), with an average reduction of 2.2 t ha(-1) (29%). Significant N x genotype level interaction was observed for NUE. Crop N uptake at harvest on average was reduced from 227 kg N ha(-1) under high N (HN) to 109 kg N ha(-1) under LN conditions while N-utilization efficiency (grain DM yield per unit crop N uptake at harvest; NUtE) increased from 34.0 to 52.1 kg DM kg(-1) N. Overall genetic variability in NUE under LN related mainly to differences in NUtE rather than N-uptake efficiency (crop N uptake at harvest per unit N available from soil and fertilizer; NUpE). However, at one site there was also a positive correlation between NUpE and NUE at LN in both years. Moreover, across the 2 year/four site network, the N x genotype effect for NUpE partly explained the N x genotype effect for grain yield and NUE. Averaging across the 16 genotypes, the timing of onset of senescence explained 86% of the variation in NUtE amongst site-season-N treatment combinations. The linear regression of onset of senescence on NutE amongst genoytpes was not significant under HN, but at three of the four sites was significant under LN explaining 32-70% of the phenotypic variation amongst genotypes in NutE. Onset of senescence amongst genotypes was negatively correlated with the efficiency with which above-ground N at anthesis was remobilized to the grain under LN. It is concluded that delaying the onset of post-anthesis senescence may be an important trait for increasing grain yield of wheat grown under low N supply. (C) 2011 Elsevier B.V. All rights reserved.