摘要： 为揭示减氮下利用多穗型品种增加密度实现绿色增产稳产的可行性，研究了4种氮水平与3种种植密度互作对小麦根系、光合、品质及产量的影响。结果表明，相同氮水平下根长、根表面积、平均根直径受密度影响不显著，根体积和根尖数受密度影响显著，相同密度下N1（传统施氮量）根长、根表面积、根体积、根尖数显著高于N3（70%N1）。相同密度减氮15%（N2，85%传统施氮量）小麦孕穗期旗叶面积不会显著降低，而减氮30%会显著降低。叶绿素含量受密度影响不显著，D1（180万株/hm²）和D3（360万株/hm²）密度下N1叶绿素含量显著高于N3。同一氮水平下，密度增加光合速率、气孔导度、蒸腾速率降低，胞间CO₂浓度上升，D1、D2（270万株/hm²）、D3下N1比N3光合速率和气孔导度显著增加20.03%，18.44%，17.36%和24.11%，20.40%，19.76%。籽粒蛋白质、淀粉、湿面筋含量及沉降值受密度影响不显著，N1与N3间蛋白质含量和沉降值差异显著，而淀粉、湿面筋含量差异不显著。相同氮水平下，增加180万株/hm²基本苗显著提高小麦各生育期群体干物重，施氮量由N1降到N3群体干物重显著降低，N2D3和N3D3群体干物重高于或相当于N1D1和N1D2，N3D3群体干物重高于或相当于N2D1和N2D2。N1、N2、N3下D3比D1产量在2016，2017年显著增加了11.83%，11.42%，14.03%和5.52%，10.31%，10.88%，N3D2和N3D3产量高于或相当于N1D1。研究得出，减氮15%～30%下密度增加90～180万株/hm²基本苗可获得高于或相当于其对应未减氮处理的生物和经济产量。

关键词: 根系性状, 旗叶面积, 光合, 籽粒品质

Abstract: In order to reveal the feasibility of increasing and maintaining yield with green agriculture development by using multiple spike cultivar to enhance density based on decreasing nitrogen application rate, we studied the effects of the interaction of four nitrogen fertilization levels and three planting density on root traits, photosynthesis, grain quality and yield of wheat. Under the same nitrogen level, the length, surface area, average diameter of root were insignificantly affected by planting density, while root volume and root tips were significantly affected by planting density, the root length, root surface area, root volume and root tips of N1 (traditional N application amount)were significant higher than that of N3 (70% N1)under the same planting density. Under the same planting density, the flag leaf area was not significantly reduced at booting stage when decreasing 15% nitrogen (N2, 85% traditional N application amount)application amount, while was significantly reduced by decreasing 30% N application amount. Chlorophyll content was not significantly affected by planting density, the chlorophyll content of N1 was significantly higher than that of N3 under the density of D1 (180×10⁴ plants/ha)and D3 (360×10⁴ plants/ha). Under the same nitrogen level, to increase planting density would led to photosynthetic rate, stomatal conductance and transpiration rate increased and intercellular CO₂ concentration decreased, when compared to N3, N1 significantly increased photosynthetic rate and stomatal conductance by 20.03%, 18.44%, 17.36% and 24.11%, 20.40%, 19.76% under D1, D2 (270×10⁴ plants/ha), D3. The grain protein, starch, wet gluten and sedimentation value was insignificantly affected by density, the difference in protein content and sedimentation value between N1 and N3 was significant, while in starch and wet gluten content were in significant. Under the same nitrogen level, to increase the density of 180×10⁴ plants/ha basic seedlings could significantly enhance the population dry matter weight of wheat at each stages, the population dry matter weight was significantly decreased when N application amount reduced from N1 to N3, the biological yield of N2D3 and N3D3 were higher than or equal to N1D1 and N1D2, and the biological yield of N3D3 was higher than or equal to N2D1 and N2D2. Compared to D1, under N1, N2, N3, D3 increased the yield by 11.83%, 11.42%, 14.03% and 5.52%, 10.31%, 10.88% respectively in 2016 and 2017, the yield of N3D2 and N3D3 were higher than or equal to N1D1. All the findings showed that when to reduce 15%-30% N and increase the density of 90×10⁴-180×10⁴ plants/ha basic seedlings could lead to biological and economic yield higher than or equal to that of the treatment without N reduction.

Key words: Root traits, Flag leaf area, Photosynthesis, Grain quality

中图分类号: 

• S512.01

• S141.1