不同氮响应型冬小麦品种植株氮素利用的差异及氮肥的调控研究

Nitrogen Translocation in Winter Wheat Varies with Cultivars and Nitrogen Fertilization

【目的】明确不同氮响应型冬小麦品种氮素吸收利用对氮肥的响应差异,挖掘黄土高原麦区冬小麦品种的高效高产潜力。【方法】于2018—2019年在山西农业大学校内小麦试验基地开展试验,试验主区为良星99、邯麦13、山农22、良星77、烟农999和山农29共6个冬小麦品种,副区为150、270 kg/hm^(2)的2个施氮水平,分析不同氮响应型冬小麦产量及氮效率与植株氮素吸收利用的关系。【结果】根据氮响应度将6个冬小麦品种聚类划分为强响应型品种(山农29、邯麦13和烟农999)和弱响应型品种(良星77、山农22和良星99)。强响应型品种较弱响应型品种显著提高了籽粒氮素积累量、花前植株氮素运转量、花后植株氮素积累量、产量以及氮效率,其中产量及氮效率分别增加17.85%~22.35%、9.20%~12.31%,显著降低了成熟期20~200 cm土层土壤硝态氮量。施氮量270 kg/hm^(2)较150 kg/hm^(2)强响应型品种成熟期茎秆+叶鞘、叶片氮素积累量和百公斤籽粒吸氮量显著降低,花前植株氮素运转量及其对籽粒的贡献率、花后植株氮素积累量、花前茎秆+叶鞘、叶片氮素运转量及其贡献率显著提高,氮素利用效率和产量分别显著增加11.98%和4.89%;弱响应型品种各器官氮素积累量增加,籽粒氮素积累量所占比例下降,花前植株、茎秆+叶鞘氮素运转量及其对籽粒的贡献率显著提高,产量显著提高7.87%,成熟期0~120cm土层土壤硝态氮量显著提高,百公斤籽粒吸氮量降低不显著。此外,在同类品种不同施氮量条件下,产量、氮素利用效率、百公斤籽粒吸氮量均与花前整株氮素运转量相关性更高,且强响应型小麦品种的相关性高于弱响应型品种的。【结论】强响应型品种产量、氮素利用效率高,器官中积累氮素向籽粒运转能力强,且花前茎秆+叶鞘、叶片氮素运转量可以作为氮高效品种的筛选指标。施氮量270 kg/hm^(2)较150 kg/hm^(2)促进强响应型品种产量及氮素利用效率显著增加,保证高产高效。

【Background】Excessive application of nitrogen fertilizer is often used by farmers in China as an insurance to guarantee winter wheat yield despite its detrimental impact on the environments such as leaching to groundwater and development of eutrophication.Breeding new varieties with improved nitrogen use efficiency is an alternative to sustain wheat production without compromising the environment.【Objective】The objective of this paper is to experimentally compare the difference in nitrogen uptake and translocation between different varieties of winter wheat in response to nitrogen fertilization in the loess plateau of China.【Method】The experiment was conducted from 09/2018 to 07/2019 at Taigu experimental station of Shanxi Agricultural University.We compared six cultivars:Liangxing 99,Hanmai 13,Shannong 22,Liangxing 77,Yannong 999 and Shannong 29.Added to each cultivar was two nitrogen fertilizations:150 kg/hm^(2) and 270 kg/hm^(2).In each treatment,we analyzed the relationship between wheat yield and N use efficiency(NUE)as well as N translocation.【Result】The varieties Shannong-29,Hanmai-13 and Yannnong-999 were more N-use efficient.Compared with other three varieties,they saw a significant increase in N accumulation in grains and pre-anthesis N translocation and post-anthesis N accumulation;their grain yield and NUE thus increased by 17.85%~22.35%and 9.20%~12.31%,respectively,due to the increased N uptake from the 20~200 cm soil.Fertilization also affected N translocation and accumulation.For the three N-efficient varieties,increasing N application from 150 kg/hm^(2) to 270 kg/hm^(2) significantly reduced N accumulation in stem,sheath,leaves and the grains,but boosted pre-anthesis N translocation in stem,sheath and leaves,and post-anthesis N accumulation in the grains.These combined to increase average grain yield and NUE by 11.98%and 4.89%,respectively.For the varieties with low N use efficiency,increasing N application also boosted N accumulation in their grains though not as significant as in other varieties.For the same variety,its yield,NUE and N content in the grains were all positively correlated with pre-anthesis N translocation,especially for the varieties with high NUE.【Conclusion】Wheat varieties with high NUE gave high yield because they are more efficient to translocate N from organs to the grains.Pre-anthesis N translocation in stem,sheath and leaves can be used as a proxy for NUE.In terms of fertilization,increasing N fertilizer application from 150 kg/hm^(2) to 270 kg/hm^(2) can promote yield and NUE,especially the varieties with high NUE.