植物生态学报 ›› 2024, Vol. 48 ›› Issue (12): 1637-1649.DOI: 10.17521/cjpe.2024.0047  cstr: 32100.14.cjpe.2024.0047

所属专题: 植物功能性状

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氮素和水分添加对黑沙蒿(Artemisia ordosica)种子功能性状的影响

马斌1,佘维维2,秦欢1,宋春阳1,袁新月1,苗春2,刘靓1,冯薇1,秦树高2,张宇清2   

  1. 1. 北京林业大学水土保持学院
    2. 北京林业大学
  • 收稿日期:2024-02-18 修回日期:2024-05-10 出版日期:2024-12-20 发布日期:2024-12-20
  • 通讯作者: 张宇清

Effects of nitrogen and water addition on seed functional traits of Artemisia ordosica

Ma Bin1,Wei-Wei SHE2,3,Qin Huan1,Song Chunyang1,Yuan Xinyue1,Chun MIAO2,3,Liu Liang1,Feng Wei1,Qin shugao2,3,Yuqing Zhang4   

  1. 1. School of Soil and Water Conservation, Beijing Forestry University
    2. Beijing Forestry University
    3. Beijing Forestry University
    4.
  • Received:2024-02-18 Revised:2024-05-10 Online:2024-12-20 Published:2024-12-20
  • Contact: Yuqing Zhang

摘要: 种子性状对植物种群繁殖更新具有重要影响,了解黑沙蒿(Artemisia ordosica)种子性状对氮沉降及降雨变化的响应,可为预测未来气候变化背景下荒漠植物群落演替方向提供理论基础。本文以宁夏毛乌素沙地连续8年的野外水、氮控制实验(2015~2022;自然降雨、增水20%、增水40%和0、20、60 kg N ha?1 yr?1全因子交互)平台为依托,测定了水、氮添加对黑沙蒿种子形态、生理和化学性状的影响;采用培养皿萌发实验并通过观测萌发种子数量计算各萌发指标,探究了各处理种子在两种培养温度下(25℃/15℃、20℃/10℃)的萌发特性。结果表明:(1)氮、水添加及其交互作用,均显著改变了黑沙蒿种子质量、长度、宽度、曲率、体积、形状系数等形态性状,增水使种子变小,增氮使种子变大,增水20%削弱了增氮对种子变大的作用,增水40%时,增氮使种子变小;(2)常温下(25℃/15℃)种子萌发率总体高于低温(20℃/10℃),低温下,种子萌发性状受亲本水氮添加影响更大,且仅增水20%、40%处理下,种子萌发率更高;(3)水氮添加处理下,种子长、宽、质量等形态大小性状调节扩散和幼苗建立功能,种子形状系数、2h吸水率、氮含量、萌发率和萌发速率共同调节种子萌发时间,单独增水或增氮使黑沙蒿种子只倾向于单一功能(扩散建立或萌发)的变异,而同时增水增氮使黑沙蒿种子两类功能均发生变异。研究结果表明,黑沙蒿种群繁殖更新策略在全球气候变化中有较大的可塑性,可通过种子性状变异,改变在氮沉降及降雨增多情形下的种子扩散建立与萌发功能策略。

关键词: 氮沉降, 降雨增多, 黑沙蒿, 种子性状, 萌发, 繁殖

Abstract: Aims Seed traits are of great significance for clarifying plant population reproduction and renewal strategies. Understanding the response of Artemisia ordosica seed traits to nitrogen deposition and increased precipitation can improve the understanding of desert plant community succession. Methods The study was conducted based on an 8-year field water and nitrogen control experiment (2015-2022). A full factor interaction experiment of ambient precipitation, 20% water increase, 40% water increase and 0, 20, 60 kg N ha?1 yr?1 were carried out to determine the morphological, physiological, chemical and germination traits of A. ordosica seeds. The germination traits of seeds under each treatment at two temperatures (25℃/15℃ and 20℃/10℃) were explored by using the petri dish germination experiment and calculating the germination indexes by observing the number of seedling emergence. Important Findings (1) Nitrogen and water addition, as well as their interactions, significantly influenced the morphological characteristics of A. ordosica seeds, including seed mass, length, width, curvature, volume, form coefficient and other traits. The addition of water resulted in smaller seeds while nitrogen alone led to larger seeds. However, when water was increased by 20%, it mitigated the effect of nitrogen increase on seed size. Conversely, with a 40% increase in water content, nitrogen addition caused smaller seeds. (2) The germination percentage was higher at normal temperature (25℃/15℃) than that at low temperature conditions (20℃/10℃). At low temperature, seed germination traits were more affected by parental water and nitrogen addition, and when only adding 20% and 40% water, the seeds had higher germination percentage. (3) Increase water or nitrogen alone tent to the variation of only one function (dispersal establishment or germination) of A. ordosica seeds, while simultaneous addition of water and nitrogen led to the variation of both functions of A. ordosica seeds. These findings demonstrate that populations of A. ordosica possessed a great adaptability in response to global climate change by altering their functional strategies of seed dispersal establishment and germination under different circumstances through the variation of seed traits.Methods The study was conducted based on an 8-year field water and nitrogen control experiment (2015-2022). Natural precipitation, 20% water increase, 40% water increase and 0, 20, 60 kg N ha?1 yr?1 full factor interaction were used to determine the morphological, physiological, chemical and germination traits of Artemisia ordosica seeds. Two-factor analysis of variance and principal component analysis were used to explore the effects of water and nitrogen addition on seed traits of Artemisia ordosica. Important Findinds (1) Nitrogen and water supplementation, as well as their interactions, significantly influenced the morphological characteristics of Artemisia ordosica seeds, including seed mass, length, width, curvature, volume, shape coefficient, and other traits. The addition of water resulted in smaller seeds while nitrogen alone led to larger seeds. However, when water was increased by 20%, it mitigated the effect of nitrogen increase on seed size. Conversely, with a 40% increase in water content, nitrogen addition caused smaller seeds. (2) The impact of nitrogen addition was more significant than that of water supplementation. The germination rate was higher at normal temperature (25℃/15℃) than that at low temperature conditions (20℃/10℃). However, when only adding 20% water, the seeds had higher germination rate and the highest germination rate occurred under the low temperature condition. (3) Under combined treatments of water and nitrogen supplementation, the shape coefficient, nitrogen content, and various aspects was related to germination such as 2-hour water absorption capacity and overall germination rate jointly regulated the timing function for seed germination. The increase in both water and nitrogen enhanced the ecological coordination strategy employed by Artemisia ordosica seeds. These findings demonstrates that populations of Artemisia ordosica possessed a great adaptability in response to global climate change by altering their functional traits to coordinate ecological functions under different environmental conditions.

Key words: Nitrogen deposition, increased precipitation, Artemisia ordosica, seed traits, germination, reproduction