Department of Crop Physiology, Crop Research Institute, Drnovská 507, 16106 Prague, Czech Republic.
Rapid Commun Mass Spectrom. 2010 Feb;24(3):261-6. doi: 10.1002/rcm.4382.
The delta(15)N signature of plants integrates various processes in soil and plant. In this study, the effect of different water regimes applied during the period of grain growth of winter wheat on grain delta(15)N was examined in a 4-year field experiment. The treatments comprised water shortage (S), an ample water supply (W), and rain-fed crop (R). Zero fertilization (N0) and 200 kg N.ha(-1) in mineral fertilizer (N1) treatments were studied. The grain (15)N was determined during grain growth and at maturity. The water regime, nitrogen application and year had a significant effect on mature grain delta(15)N (p < 0.001). Water and nitrogen explained 54.6% of the variability of delta(15)N in the experiment, the year accounted for 10.7% and the interactions for another 19.6% of the total variability. The analysis of non-mature grain delta(15)N showed significant effects of N and year but not of water. Nitrogen fertilization reduced the delta(15)N of mature grain in years by 0.7-6.3 per thousand in comparison with N0 plants; the reduction was more pronounced under stress (average reduction by 4.1 per thousand) than under rain-fed (2.4 per thousand) and ample water supply (2.2 per thousand). Water stress decreased the grain delta(15)N in fertilized wheat, by 0.1-2.1 per thousand and 0.6-3.6 per thousand in experimental years, on average by 1.30 per thousand and 1.79 per thousand in comparison with the R and W water supply, respectively. The effect of water supply was not significant in non-fertilized wheat. A significant negative linear relationship between grain N concentration and delta(15)N in maturity or during the grain growth (R(2) = 0.83, R(2) = 0.76, respectively) was found. The observed sources of grain delta(15)N variability should be taken into consideration when analyzing and interpreting the data on the delta(15)N signature of plant material from field conditions.
植物的 δ¹⁵N 特征综合了土壤和植物中的各种过程。本研究通过 4 年田间试验，研究了冬小麦籽粒生长期间不同水分处理对籽粒 δ¹⁵N 的影响。处理包括水分胁迫（S）、充足供水（W）和雨养作物（R）。研究了零施肥（N0）和 200kgN·ha⁻¹ 矿物肥（N1）处理。在籽粒生长和成熟过程中测定了籽粒（¹⁵N）。水分、氮素处理和年份对成熟籽粒 δ¹⁵N 有显著影响（p＜0.001）。水分和氮素解释了实验中 δ¹⁵N 变异的 54.6%，年份解释了 10.7%，相互作用解释了另外 19.6%。非成熟籽粒 δ¹⁵N 的分析表明，氮素和年份有显著影响，但水分没有显著影响。与 N0 植株相比，氮素施肥使成熟籽粒 δ¹⁵N 在不同年份降低了 0.7-6.3‰；胁迫下（平均降低 4.1‰）比雨养（2.2‰）和充足供水（2.2‰）下更为显著。水分胁迫使施肥小麦的籽粒 δ¹⁵N 降低了 0.1-2.1‰和 0.6-3.6‰，与 R 和 W 供水相比，平均降低了 1.30‰和 1.79‰。非施肥小麦中供水的影响不显著。在成熟或籽粒生长期间，发现籽粒 N 浓度与 δ¹⁵N 之间存在显著的负线性关系（R²=0.83，R²=0.76）。在分析和解释田间条件下植物材料 δ¹⁵N 特征的数据时，应考虑到观察到的籽粒 δ¹⁵N 变异性来源。
