硝铵供应比对油菜光合作用的影响  

Effects of nitrate to ammonium ratio on photosynthesis of Brassica napus L.

作　　者：张珊珊 张佳祺 李银水[1] 代晶 顾炽明 杨璐 胡文诗 秦璐[1] 廖星[1] ZHANG Shan-shan;ZHANG Jia-qi;LI Yin-shui;DAI Jing;GU Chi-ming;YANG Lu;HU Wen-shi;QIN Lu;LIAO Xing(Oil Crops Research Institute of Chinese Academy of Agricultural Sciences/Key Laboratory of Biology and Genetic Improvement of Oil Crops,Ministry of Agriculture and Rural Affairs,Wuhan,Hubei 430062,China)

机构地区：[1]中国农业科学院油料作物研究所/农业农村部油料作物生物学与遗传育种重点实验室,湖北武汉430062

出　　处：《植物营养与肥料学报》2024年第5期966-979,共14页Journal of Plant Nutrition and Fertilizers

基　　金：湖北省青年拔尖人才项目;中央级科研院所基本科研业务费专项(1610172022008);中国农业科学院创新工程项目(CAASASTIP-2013-OCRI)。

摘　　要：【目的】油菜是我国重要的油料作物,当铵态氮(NH_(4)^(+)-N)作为唯一氮源时,油菜的光合作用受到显著抑制,添加硝态氮(NO_(3)^(−)-N)能显著缓解NH_(4)^(+)-N的抑制效应。探究不同硝铵配比对油菜叶片光合能力的影响,明确硝态氮调控油菜光合能力的生理机制,对优化施用氮肥形态,保障冬油菜扩面增产有重要意义。【方法】利用水培试验方法,在高氮(8 mmol/L,HN)和低氮(1 mmol/L,LN)处理下,设置全硝、硝铵3∶1、硝铵1∶1、硝铵1∶3、全铵5个配合比例,在处理15、20、25天时,取油菜样品,测定光合能力参数和生物量。利用光合限制模型分析硝铵比对光合速率的限制。【结果】全铵处理的油菜在HN处理下第5天和LN处理下第7天开始出现枯黄症状,直至18天全部死亡,在处理15天后,植株生物量差异显著。与硝铵3∶1相比,硝铵1∶1处理生物量降低了5.6%~61.3%,硝铵1∶3处理下降了6.9%~110.6%。同一氮水平下,不同硝铵比例叶片全氮含量无显著差异,然而硝态氮和铵态氮含量差异显著,硝铵3∶1处理叶片硝态氮含量显著高于硝铵1∶1和1∶3处理,分别高出91.7%~292.7%和130.0%~1255.0%;而叶片铵态氮含量在生长后期以硝铵1∶3配比显著高于硝铵3∶1和全硝处理,分别高出52.6%~53.3%和61.1%~76.9%。硝态氮添加显著提高叶片净光合速率(A),硝铵3∶1配比的A最高,较硝铵1∶1和1∶3配比的A显著提高了16.7%~50.3%;硝铵3∶1处理显著提高了最大净光合速率(Amax)、最大羧化速率(Vcmax)、最大电子传递速率(Jmax)和叶肉导度(gm),分别提高了6.8%~107.4%、9.2%~79.5%、50.5%~115.8%和8.6%~134.8%。A随叶片硝态氮浓度和硝态铵态氮含量比值增加而增加,在硝态氮含量超过120.2~151.2μg/g,比值超过2.6~3.2后,不再显著变化。通过光合限制模型分析,硝态氮添加提高油菜光合速率是通过降低生化限制和叶肉导度限制。【结论】适当提高油菜氮肥的硝铵�【Objectives】Oilseed rape(Brassica napus L.)is the third largest oil crop in the world.The growth of oilseed rape is strongly inhibited by the pure NH_(4)^(+)-N supply.We explored the effects of nitrate to ammonium ratios on the photosynthetic capacity of oilseed rape,to optimize nitrogen forms and increase yield of winter oilseed rape.【Methods】A hydroponic culture method was used for the research.High and low N nutrition solution were prepared by regulating total N concentrations at 8 mmol(HN)and 1 mmol(LN).The N source treatments in the nutrient solutions included total nitrate(TN),total ammonium(TA),and nitrate to ammonium ratio of 3∶1(3N1A),1∶1(1N1A),and 1∶3(1N3A),respectively.At the 15,20 and 25 days of treatment,the photosynthetic parameters of seedling leaves were monitored,and the rapeseed seedlings were harvested for the investigation of N content and biomass.The limitation of N forms was expatiated by photosynthetic restriction model.【Results】The seedlings in TA treatment started to wither and became yellowing since 5 days under HN and 7 days under LN treatment,and died completely at 18 days of treatment.Compared with 3N1A treatment,1N1A and 1N3A treatments decreased the biomass by 5.6%−61.3%and 6.9%−110.6%,respectively.Under the same N level,the nitrate to ammonium ratio treatments were close in leaf total N content,but significantly different in NO_(3)^(−)-N and NH_(4)^(+)-N contents.The leaves contained 91.7%−292.7%and 130.0%−1255.0%higher NO_(3)^(−)-N content in 3N1A treatment than those in 1N1A and 1N3A treatment.The leaves of 1N3A treatment contained 52.6−53.3%and 61.1-76.9%higher NH_(4)^(+)-N content than in 3N1A and TN treatment.The supply of NO_(3)^(−)-N enhanced the net photosynthetic rate(A)significantly,which in 3N1A treatment was 16.7%−50.3%higher than in 1N1A and 1N3A treatment.3N1A treatment significantly increased the maximum net photosynthetic rate(Amax),maximum carboxylation rate(Vcmax),maximum electron transfer rate(Jmax)and mesophyll conductance(gm)

关 键 词：油菜 硝铵比 硝态氮 光合能力 叶肉导度 

分 类 号：S565.4[农业科学—作物学]