【作者】 张旭；

【导师】 王益；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2021， 硕士

【摘要】 氮素是植物生长发育必须的大量营养元素之一。硝态氮（NO₃^--N）和铵态氮（NH₄⁺-N）是植物吸收和利用的两种主要的无机氮素形态。不同氮素形态会不同地影响作物的生长发育,但对小麦的形态、生理以及金属营养元素的吸收、转运和积累的影响尚不清楚。本研究以矮秆波兰小麦（Triticum polonicum L.,AABB,2n=4x=28）为对象,分析N-Null、NH₄⁺-N、NO₃^--N和NH₄⁺-N+NO₃^--N四种处理下苗期矮秆波兰小麦的形态指标、生理指标、组织部位金属营养元素含量和根部差异表达基因,揭示不同氮素形态调节矮秆波兰小麦苗期的生长和组织部位金属营养元素的吸收、转运和积累的影响,为合理利用氮素提高作物产量与品质提供理论依据。主要研究结果如下:（1）与N-Null相比,添加NH₄⁺-N显著降低了总根体积和总根表面积,不影响株高、主根长、根部和地上部鲜重和干重、总根长、平均根系直径、根尖数和分支数;添加NO₃^--N不影响植株形态指标和根系参数;添加NH₄⁺-N+NO₃^--N只显著增加了株高,不影响植株其它形态指标和根系参数。与添加NH₄⁺-N相比,添加NH₄⁺-N+NO₃^--N增加了株高,不影响其它形态指标和根系参数;与添加NO₃^--N相比,添加NH₄⁺-N+NO₃^--N不影响形态指标和根系参数。（2）与N-Null相比,添加NH₄⁺-N显著降低了胞间CO₂浓度,提高了水蒸汽压亏缺;添加NO₃^--N显著提高了水蒸汽压亏缺;添加NH₄⁺-N+NO₃^--N显著提高了蒸腾速率和水蒸汽压亏缺,降低了胞间CO₂浓度和水分利用率。与添加NH₄⁺-N相比,添加NH₄⁺-N+NO₃^--N显著提高了水蒸汽压亏缺,降低了水分利用率;与添加NO₃^--N相比,添加NH₄⁺-N+NO₃^--N显著降低了水分利用率。（3）与N-Null相比,添加NH₄⁺-N和NO₃^--N降低了根、地上部和整株的Zn浓度和含量。添加NH₄⁺-N+NO₃^--N提高了根的Zn浓度和含量。与添加NH₄⁺-N或NO₃^--N相比,添加NH₄⁺-N+NO₃^--N提高了根、地上部和整株中的Zn浓度与含量。与N-Null相比,添加NH₄⁺-N降低了根的Fe浓度和含量。添加NO₃^--N提高了根的Fe浓度,降低了地上部Fe浓度和含量。添加NH₄⁺-N+NO₃^--N降低了地上部的Fe浓度和含量以及整株的Fe浓度。与添加NO₃^--N相比,添加NH₄⁺-N+NO₃^--N只降低了根的Fe浓度。与N-Null相比,添加NH₄⁺-N、NO₃^--N和NH₄⁺-N+NO₃^--N均降低了对Fe的转运;在NO₃^--N背景下添加NH₄⁺-N促进了Fe的转运。与N-Null相比,添加NH₄⁺-N、NO₃^--N和NH₄⁺-N+NO₃^--N均降低了根、地上部和整株的Cu浓度。与N-Null相比,添加NH₄⁺-N、NO₃^--N和NH₄⁺-N+NO₃^--N降低了根的Mg浓度。与添加NH₄⁺-N或NO₃^--N相比,添加NH₄⁺-N+NO₃^--N均不影响组织的Mg浓度和含量,但促进了Mg的转运。与N-Null相比,添加NH₄⁺-N、NO₃^--N和NH₄⁺-N+NO₃^--N均降低了各组织和整株的Mn浓度和含量。与添加NO₃^--N相比,添加NH₄⁺-N+NO₃^--N降低了根和整株的Mn浓度,提高了对Mn的转运。与N-Null相比,添加NH₄⁺-N+NO₃^--N降低了地上部和整株的Ca浓度和含量。与添加NH₄⁺-N或NO₃^--N相比,添加NH₄⁺-N+NO₃^--N降低了地上部和整株的Ca浓度和含量。（4）与N-Null相比,添加NH₄⁺-N引起45个基因上调表达,80个基因下调表达;添加NO₃^--N引起98个基因上调表达,242个基因下调表达。添加NH₄⁺-N+NO₃^--N引起170个基因上调表达,157个基因下调表达。与添加NH₄⁺-N相比,添加NH₄⁺-N+NO₃^--N引起97个基因上调表达,82个基因下调表达。与添加NO₃^--N相比,添加NH₄⁺-N+NO₃^--N引起123个基因上调表达,35个基因下调表达。这些差异表达基因主要涉及转运蛋白、糖类代谢、苯丙氨酸代谢、次生代谢物的合成等途径。因此,差异表达基因可能会影响幼苗的生长发育、光合呼吸以及对金属营养元素的吸收、转运和积累。更多还原

【Abstract】 Nitrogen is one of the essential nutrients for plant growth and development.Nitrate nitrogen（NO₃^--N）and ammonium nitrogen（NH₄⁺-N）are two main inorganic nitrogen forms for plant absorption and utilization.Different nitrogen forms can differentally affect the growth and development of crops,but the effects on the morphology,physiology and the absorption,transportation and accumulation of metal nutrients in wheat are still unclear.In this study,the seeding of dwarf Polish wheat（Triticum polonicum L.,AABB,2n=4x=28）were treated four nitrogen forms including N-Null,NH₄⁺-N,NO₃^--N and NH₄⁺-N+NO₃^--N.Several morphological and physiological indexes,metal nutrients content in tissues,and the differentially expressed genes of root were investigated.The aims were to reveal the effects of different nitrogen forms on plant growth,and the absorption,transportation and accumulation of metal nutrients,which would provide a theoretical basis for the application of nitrogen fertilizer to improve crop yield and quality.The main results are as follows:（1）Compared with N-Null,NH₄⁺-N significantly reduced total root volume and total root surface area,but did not affect plant height,main root length,fresh and dry weight of root and shoot,total root length,average root diameter,root tip number and branch number.Addition of NO₃^--N did not affect all morphological indexes of root and shoot.Addition of NH₄⁺-N+NO₃^--N significantly increased plant height,but did not affect other morphological indexes of root and shoot.Compared with addition of NH₄⁺-N,addition of NH₄⁺-N+NO₃^--N increased plant height without affecting other morphological indexes of root and shoot;Compared with addition of NO₃^--N,addition of NH₄⁺-N+NO₃^--N did not affect the morphological indexes of root and shoot.（2）Compared with N-Null,addition of NH₄⁺-N significantly reduced the intercellular CO₂ concentration and increased the water vapor pressure deficit.Addition of NO₃^--N significantly increased the water vapor pressure deficit.Addition of NH₄⁺-N+NO₃^--N significantly increased transpiration rate and water vapor pressure deficit,and decreased intercellular CO₂ concentration and water use efficiency.Compared with addition of NH₄⁺-N,addition of NH₄⁺-N+NO₃^--N significantly increased the water vapor pressure deficit and decreased the water use efficiency.Compared with NO₃^--N,addition of NH₄⁺-N+NO₃^--N significantly decreased water use efficiency.（3）Compared with N-Null,addition of NH₄⁺-N or NO₃^--N reduced the concentration and content of Zn in roots,shoots and per plant.Addition of NH₄⁺-N+NO₃^--N increased the concentration and content of Zn in roots.Compared with addition of NH₄⁺-N or NO₃^--N,addition of NH₄⁺-N+NO₃^--N increased the concentration and content of Zn in roots,shoots and per plant.Compared with N-Null,addition of NH₄⁺-N reduced the concentration and content of Fe in roots;addition of NO₃^--N increased the concentration of Fe in roots and reduced the concentration and content of Fe in shoots.Addition of NH₄⁺-N+NO₃^--N reduced the concentration and content of Fe in shoots and the concentration of Fe in per plant.Compared with addition of NO₃^--N,addition of NH₄⁺-N+NO₃^--N only reduced the concentration of Fe in roots.Compared with N-Null,addition of NH₄⁺-N,NO₃^--N and NH₄⁺-N+NO₃^--N reduced the translocation of Fe;addition of NH₄⁺-N in the background of NO₃^--N promoted the translocation of Fe.Compared with N-Null,the concentration of Cu in roots,shoots and per plant was decreased by addition of NH₄⁺-N,NO₃^--N and NH₄⁺-N+NO₃^--N.Compared with N-Null,addition of NH₄⁺-N,NO₃^--N and NH₄⁺-N+NO₃^--N reduced the concentration of Mg in roots.Compared with addition of NH₄⁺-N or NO₃^--N,addition of NH₄⁺-N+NO₃^--N did not affect the concentration and content of Mg in tissues,but promoted the translocation of Mg.Compared with N-Null,addition of NH₄⁺-N,NO₃^--N and NH₄⁺-N+NO₃^--N decreased the concentration and content of Mn in tissues.Compared with addition of NO₃^--N,addition of NH₄⁺-N+NO₃^--N decreased the concentration of Mn in roots and per plant,enhanced the translocation of Mn.Compared with N-Null,addition of NH₄⁺-N+NO₃^--N reduced the concentration and content of Ca in shoots and per plant.Compared with addition of NH₄⁺-N or NO₃^--N,addition of NH₄⁺-N+NO₃^--N reduced the concentration and content of Ca in shoots and per plant.（4）Compared with N-Null,addition of NH₄⁺-N up regulated 45 genes and down regulated 80 genes.Addition of NO₃^--N up regulated 98 genes and down regulated 242genes.Addition of NH₄⁺-N+NO₃^--N up regulated 170 genes and down regulated 157 genes.Compared with addition of NH₄⁺-N,addition of NH₄⁺-N+NO₃^--N up regulated 97 genes and down regulated 82 genes.Compared with addition of NO₃^--N,addition of NH₄⁺-N+NO₃^--N up regulated 123 genes and down regulated 35 genes.The differentially expressed genes are mainly involved in transporter,carbohydrate metabolism,phenylalanine metabolism and secondary metabolite synthesis.Therefore,the differentially expressed genes may affect the growth and development of seedlings,photosynthetic respiration and the absorption,transportation and accumulation of metal nutrients.更多还原