文献类型：期刊文献

中文题名：氮添加下干旱对油茶根系氮吸收与分配的影响

英文题名：Effects of drought on nitrogen uptake and distribution in Camellia oleifera root under nitrogen addition

作者：姜孝曾[1] 祝燕[2] 周恒伟[1] 黄兴召[1] 傅龙龙[3] 万芳芳[1]

第一作者：姜孝曾

机构：[1]安徽省林木资源培育重点实验室,安徽农业大学林学与园林学院,安徽合肥230036;[2]中国林业科学研究院林业研究所,北京100091;[3]金寨县林业局,安徽六安237300

年份：2025

卷号：49

期号：1

起止页码：95-102

中文期刊名：南京林业大学学报(自然科学版)

外文期刊名：Journal of Nanjing Forestry University:Natural Sciences Edition

收录：;北大核心:【北大核心2023】；

基金：教育部重点实验室开放基金项目(BFUKF202301);安徽省教育厅科研项目(2023AH051040);安徽农业大学人才启动经费(yj2020-13)。

语种：中文

中文关键词：油茶;氮添加;干旱胁迫;根序;氮肥利用

外文关键词：Camellia oleifera;nitrogenous addition;drought stress;root order;nitrogen fertilizer utilization

分类号：S718.43

摘要：【目的】探讨油茶(Camellia oleifera)不同根序根系的生长与养分利用对干旱和施氮的响应,分析水和氮素对油茶不同径级根系生长、氮素吸收、分配和利用的影响,为更好地认识气候变暖下植物根系构型与养分策略的关系提供理论支撑。【方法】以2年生‘长林53’(‘Changlin 53’)油茶幼树为试材,利用盆栽试验和^(15)N同位素示踪技术,采用双因素完全随机设计,设置2个干旱水平,即正常灌溉(土壤含水率75%±5%)和干旱(土壤含水率30%±5%);2个施氮水平,即不施氮和施^(15)N标记的硝酸铵(2.88 g/株)。干旱处理75 d后取样测定油茶幼树不同径级根系的生物量、全氮含量(质量分数,下同)、来自肥料氮的百分率(Ndff)、氮素利用率。【结果】干旱胁迫后油茶1~3级,5级和6级根的生物量与其氮含量呈负相关关系,与4级根的则呈正相关关系。干旱显著影响了各径级根系^(15)N含量和Ndff(P<0.05),抑制了各径级根系^(15)N的富集,干旱胁迫下1~3级的Ndff最高。干旱对根系的氮素分配率起促进作用,尤其是5级根氮素增加了93.10%,但在不同程度上抑制了油茶低阶根系的氮素利用率。【结论】施氮促进干旱下根系生物量和氮素分配给粗根,但不利于细根生物量和氮素的积累;干旱显著影响了各级根系对肥料氮的吸收、利用和分配,促进肥料中的氮素向根系尤其5级以上根系分配,但不同程度地抑制了1~4级根系对^(15)N的吸收和利用。
【Objective】This study investigates the growth response and nutrient utilization of the Camellia oleifera root system across different root orders under drought and nitrogen application.It aims to analyze how water and nitrogen affect root growth,nitrogen uptake,distribution and utilization,and to provide theoretical support for understanding the relationship between plant root architecture and nutrient strategies under climate warming.【Method】Two-year-old C.oleifera‘Changlin 53’trees were used.A pot experiment with 15 N isotope tracing technology was conducted,setting two drought levels:normal irrigation(soil moisture content 75%±5%)and drought(soil moisture content 30%±5%).Two nitrogen application levels were used:no nitrogen and 15 N-labeled ammonium nitrate(2.88 g/plant).After 75 days of drought treatment,the biomass,total nitrogen content,percentage of nitrogen from fertilizer(Ndff),and nitrogen use efficiency of roots of different diameter classes of C.oleifolia seedlings were measured.【Result】Under drought stress,there was a negative correlation between biomass and nitrogen content in grade 1-3,grade 5,and grade 6 roots,while a positive correlation was observed in grade 4 roots.Drought significantly affected 15 N content and Ndff in all root diameter classes(P<0.05).Drought inhibited 15 N accumulation in all root diameter classes,with Ndff in grades 1-3 being most affected.Drought increased nitrogen distribution in roots,especially in grade 5 roots,which saw a 93.10%increase.However,the nitrogen use efficiency was inhibited to varying degrees across different root diameter classes.【Conclusion】Nitrogen application increased root biomass and nitrogen allocation to coarse roots under drought but reduced fine root biomass and nitrogen accumulation.Drought significantly impacted the absorption,utilization,and distribution of fertilizer nitrogen in roots of all levels,enhancing nitrogen distribution,particularly in roots above grade 5,but inhibiting 15 N absorption and utilization in roots of grades 1-4.