氮素对棉花幼苗生长、养分分配及氮素利用效率的影响  

Effects of nitrogen on cotton growth,macronutrients distribution and nitrogen use efficiency

作　　者：陈丹丹 王金玉 彭杰 谢晓麒 卢丽文 杜轩 孟令浩 杨国正[1] Chen Dandan;Wang Jinyu;Peng Jie;Xie Xiaoqi;Lu Liwen;Du Xuan;Meng Linghao;Yang Guozheng(College of Plant Science and Technology,Huazhong Agricultural University/Key Laboratory of Crop Ecophysiology and Farming System in Middle Reaches of the Yangtze River,Ministry of Agriculture and Rural Affairs,Wuhan 430070,China)

机构地区：[1]华中农业大学植物科学技术学院/农业农村部长江中游作物生理生态与耕作重点实验室,武汉430070

出　　处：《棉花学报》2023年第6期473-486,共14页Cotton Science

基　　金：湖北洪山实验室项目(2021hszd006)。

摘　　要：【目的】筛选棉花苗期适宜的氮浓度并研究其对棉花幼苗生长、养分吸收及氮素利用效率的影响。【方法】以华棉3097为材料,设置6个氮浓度0、0.04、0.4、1、4、8 mmol·L^(-1)Ca(NO_(3))_(2),分别记为N0、N0.04、N0.4、N1、N4、N8,在培养液中培养21 d。测定棉花幼苗根系和地上部形态、干物质质量和主要营养元素吸收量及其分配、光合能力、氮素吸收效率及利用效率等指标。【结果】随着氮浓度的增加,棉花幼苗根系及地上部的生长、干物质质量、营养元素累积量、光合能力等均呈先增加后降低的趋势,4 mmol·L^(-1)Ca(NO_(3))_(2)是棉花苗期最适宜的氮浓度,其生长最旺盛。棉花幼苗单株氮、磷、钾、钙的最大积累量分别为34.4 mg、6.3 mg、41.6 mg和16.5 mg,比例约为1∶0.2∶1.2∶0.5。氮素吸收效率和利用效率均与根冠比正相关,还与根干物质分配比例、根平均直径、根养分分配比例等变化规律一致,均随氮浓度的增加而降低。在0~4 mmol·L^(-1)Ca(NO_(3))_(2)范围内,植株氮钾钙含量、叶片干物质质量和地上部养分分配比例均随氮浓度的增加而提高。【结论】4 mmol·L^(-1)Ca(NO3)2是棉花苗期最适宜的氮浓度,可显著促进棉花幼苗对氮、磷、钾、钙的吸收。1 mmol·L^(-1)Ca(NO_(3))_(2)能提高根系养分分配比例,促进根系伸长与增殖,提高氮素吸收及利用效率。[Objective]This study aims to screen the suitable nitrogen(N)concentration and investigate its effects on the growth,macronutrients uptake and N use efficiency of cotton at seedling stage.[Methods]HM3097 was used and cultured with nutrient solution for 21 d of six N concentrations with 0,0.04,0.4,1,4,8 mmol·L^(-1)Ca(NO_(3))_(2),named N0,N0.04,N0.4,N1,N4,N8,respectively.The root and shoot morphology,biomass,absorption and distribution of macronutrients,photosynthetic capacity,N uptake efficiency(NUpE)and N utilization efficiency(NUtE)of cotton seedlings were determined.[Results]With the increase of N concentration,the growth(include root and shoot),biomass,macronutrients accumulation and photosynthetic capacity of cotton seedlings increased first and then decreased,and 4 mmol·L^(-1)Ca(NO_(3))_(2)was the most appropriate N concentration for cotton at seedling stage,at which the cotton growth was the most vigorous.The maximum accumulations of N,P,K,and Ca of cotton seedlings were 34.4 mg,6.3 mg,41.6 mg,and 16.5 mg per plant,respectively,with the ratio of 1∶0.2∶1.2∶0.5.NUpE and NUtE were positively correlated with root-shoot ratio,and the change trend were also consistent with the root biomass distribution proportion,root average diameter,and the root macronutrients distribution proportion,which decreased with the increase of N concentration.In the range of 0-4 mmol·L^(-1)Ca(NO_(3))_(2),the contents of N,K,and Ca,leaf biomass and the shoot macronutrients distribution proportion all increased with the increase of N concentration.[Conclusion]4 mmol·L^(-1)Ca(NO_(3))_(2)was the most appropriate N concentration for cotton at seedling stage,which could significantly promote the absorption of N,P,K,and Ca of cotton seedlings.1 mmol·L^(-1)Ca(NO_(3))_(2)could increase the root macronutrients distribution proportion,promote root elongation and proliferation,and improve NUpE and NUtE.

关 键 词：棉花 氮 根系形态 养分分配 光合作用 

分 类 号：S562[农业科学—作物学]