Effect of wheat dwarfing genes on nitrogen-use efficiency
Effect of wheat dwarfing genes on nitrogen-use efficiency
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DOI：
10.1017/s0021859611000414
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发表时间：
2012-02-01
影响因子：
2
通讯作者：
Jones, H. E.
中科院分区：
文献类型：
--
作者：
Gooding, M. J.;Addisu, M.;Jones, H. E.
近等基因系（NIL）在cvar Mercia背景中对降低的高度（Rht）和光周期不敏感性（Ppd-D1 a）的等位基因变化在英国伯克希尔的田间试验点，但在不同的系统内，比较了Rht（高）、Rht-B1 b、Rht-D1 b、Rht-B1 c、Rht 8 c + Ppd-D1 a、Rht-D1 c、Rht 12（2005/06、2006/07和2007/08生长季节，“有机”为0; 2005/06、2006/07、2007/08和2008/09生长季节，“常规”为C）。2007年和2008年，在Mans Huntsman和Mans Widgeon背景下增加了更多的NIL（rht（tall）、Rht-B1 b、Rht-D1 b、Rht-B1 c、Rht-B1 b + Rht-D1 b、Rht-D1 b + Rht-B1 c）。对比系统允许近等基因系在不同的轮作和农艺条件下进行测试，但与商业相关，特别是关于氮可用性的假设时间分布和杂草的竞争。籽粒干物质产量/有效氮;其中有效氮=肥料氮+土壤矿质氮），（籽粒氮产量/有效氮）、氮素生产效率（NUtEg;籽粒DM产量/地上作物N产量），N收获指数（籽粒氮产量/地上作物氮产量）和干物质收获指数（DMHI;谷粒DM产量/地上作物DM产量）都在最终作物高度800-950 mm处达到峰值。有机系统中最大NUE发生在比常规系统更高的作物高度处，这样，即使在最短的背景基因Mercia中只添加一个半矮秆等位基因（Rht-D1 b），也会降低有机系统中的NUE。在地上生物量方面，矮秆等位基因对干物质积累的影响大于对氮素积累的影响，所有矮秆等位基因均降低了氮素利用效率（NUtE;作物干物质产量/作物氮产量）。这是特别明显的开花期在传统的系统中，没有严重的矮化氮积累的显着惩罚，尽管3吨（t）/公顷的生物量减少相比，最高的线。因此，籽粒中氮回收率的基因型差异主要是开花后净氮吸收的函数，而不是再动员氮的函数。除了与Ppd-D1 a结合外，这种效应与矮化复合，与延迟开花有关。在有机试验中，有更大的依赖于开花前积累的N，和基因型对NUE的影响混淆的杂草，这是负相关的作物高度积累的N的影响。因此，Rht等位基因操纵的小麦NUE及其组分最大化的最佳高度取决于生长系统和作物利用（即生物量或谷物产量）。
Near isogenic lines (NILs) varying for alleles for reduced height (Rht) and photoperiod insensitivity (Ppd-D1a) in a cvar Mercia background (rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht8c+Ppd-D1a, Rht-D1c, Rht12) were compared at a field site in Berkshire, UK, but within different systems ('organic', 0, in 2005/06, 2006/07 and 2007/08 growing seasons v. 'conventional', C, in 2005/06, 2006/07, 2007/08 and 2008/09). In 2007 and 2008, further NILs (rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht-B1b+Rht-D1b, Rht-D1b+Rht-B1c) in both Mans Huntsman and Mans Widgeon backgrounds were added. The contrasting systems allowed NILs to be tested in diverse rotational and agronomic, but commercially relevant, contexts, particularly with regard to the assumed temporal distribution of nitrogen availability, and competition from weeds.For grain, nitrogen-use efficiency (NUE; grain dry matter (DM) yield/available N; where available N=fertilizer N+soil mineral N), recovery of N in the grain (grain N yield/available N), N utilization efficiency to produce grain (NUtEg; grain DM yield/above-ground crop N yield), N harvest index (grain N yield/above-ground crop N yield) and dry matter harvest index (DMHI; grain DM yield/above-ground crop DM yield) all peaked at final crop heights of 800-950 mm. Maximum NUE occurred at greater crop heights in the organic system than in the conventional system, such that even adding just a semi-dwarfing allele (Rht-D1b) to the shortest background, Mercia, reduced NUE in the organic system. The mechanism of dwarfing (gibberellin sensitive or insensitive) made little difference to the relationship between N U E and its components with crop height.For above-ground biomass: dwarfing alleles had a greater effect on DM accumulation compared with N accumulation such that all dwarfing alleles could reduce nitrogen utilization efficiency (NUtE; crop DM yield/crop N yield). This was particularly evident at anthesis in the conventional system when there was no significant penalty for severe dwarfism for N accumulation, despite a 3-tonne (t)/ha reduction in biomass compared to the tallest lines. Differences between genotypes for recovery of N in the grain were thus mostly a function of net N uptake after anthesis rather than of remobilized N. This effect was compounded as dwarfing, except when coupled with Ppd-D1a, was associated with delayed anthesis. In the organic experiments there was greater reliance on N accumulated before anthesis, and genotype effects on NUE were confounded with effects on N accumulated by weeds, which was negatively associated with crop height. Optimum height for maximizing wheat NUE and its components, as manipulated by Rht alleles, thus depend on growing system, and crop utilization (i.e. biomass or grain production).