The combined effect of constant water deficit and nitrogen supply on WUE, NUE and Δ13C in durum wheat potted plants
The combined effect of constant water deficit and nitrogen supply on WUE, NUE and Δ13C in durum wheat potted plants
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DOI：
10.1111/j.1744-7348.2007.00195.x
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发表时间：
2007-01-01
影响因子：
2.6
通讯作者：
Araus, J. L.
中科院分区：
文献类型：
--
作者：
Cabrera-Bosquet, L.;Molero, G.;Araus, J. L.
缺水和缺氮是制约硬粒小麦产量的主要因素。在温室盆栽条件下，研究了持续水分亏缺和氮素供应(NS)对硬粒小麦生长、光合作用、气孔导度(g(S))、蒸腾作用、瞬时水分利用效率(WUE)、时间综合水分利用效率(WUE)、氮素利用效率(NUE)和碳同位素识别(Delta C-13)的综合效应。在总共24个试验处理中，测定了3个水位(40%、70%和100%容器容量)、两个施氮量(高氮和低氮)和4种基因型。在植株出苗后2周进行水分和氮素处理。在开花后2周左右，测定旗叶的生长量、氮素含量、Delta C-13和旗叶的气体交换。正如预期的那样，水和氮肥对生长都有很强的正向影响。然而，减少供水量对降低光合作用和蒸腾作用、降低Delta C-13和NUE、增加WUE的影响较小。相反，增加氮素供应水平对g(S)有显著的负面影响，显著降低胞间与环境CO2浓度的比值和Delta C-13，增加瞬时WUE和时间积分WUE。此外，较高的氮素水平也对瞬时氮素利用效率和时间积分氮素利用效率产生了负面影响。地上部的C-13增量与水分利用效率的瞬时测量或时间积分测量均呈显著负相关。此外，在每一个NS中，Delta C-13也与综合NUE呈负相关。我们的结论是，在我们的实验条件下，Delta C-13提供了有关工厂不仅使用水，而且使用氮气的效率的信息。此外，这项研究表明，在水分利用效率没有持续变化的情况下，稳定的水分限制可能会对生物量产生强烈影响。不同的水分状况对气体交换、WUE和Delta C-13缺乏影响，说明了在生长过程中如何施加压力的重要性。
Water scarcity and nitrogen shortage are the main constraints on durum wheat productivity. This paper examines the combined effects of a constant water deficit and nitrogen supply (NS) on growth, photosynthesis, stomatal conductance (g(s)) and transpiration, instantaneous and time-integrated water use efficiency (WUE) and nitrogen use efficiency (NUE) and carbon isotope discrimination (Delta C-13) in durum wheat genotypes grown in pots under greenhouse conditions. Three water levels (40%, 70% and 100% container capacity), two nitrogen doses (high and low N) and four genotypes were assayed in a total of 24 experimental treatments. Water and nitrogen treatments were imposed 2 weeks after plant emergence. The growth, nitrogen content and Delta C-13 of the shoot and the gas exchange in the flag leaf were determined about 2 weeks after anthesis. As expected, both water and NS had a strong positive effect on growth. However, a reduction in water supply had low effect decreasing photosynthesis and transpiration, Delta C-13 and NUE and increasing WUE. On the contrary, increasing the level of nitrogen supplied had a significant negative effect on g(s), which decreased significantly the ratio of intercellular to ambient CO2 concentrations and Delta C-13, and increased both instantaneous and time-integrated WUE. In addition, a higher N level also negatively affected the instantaneous and time-integrated NUE. The Delta C-13 of shoots correlated significantly and negatively with either instantaneous or time-integrated measurements of WUE. Moreover, within each NS, Delta C-13 also correlated negatively with the integrated NUE. We concluded that under our experimental conditions, Delta C-13 gives information about the efficiency with which not just water but also nitrogen are used by the plant. In addition, this study illustrates that a steady water limitation may strongly affect biomass without consistent changes in WUE. The lack of effect of the different water regimes on gas exchange, WUE and Delta C-13 illustrate the importance of how stress is imposed during growth.