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林业科学 ›› 2016, Vol. 52 ›› Issue (8): 138-145.doi: 10.11707/j.1001-7488.20160817

• 研究简报 • 上一篇    下一篇

持续N沉降对低P下2年生马尾松苗木菌根共生影响

庞丽1,2, 周志春1, 张一1, 丰忠平3   

  1. 1. 中国林业科学研究院亚热带林业研究所 浙江省林木育种技术研究重点实验室 国家林业局 马尾松工程技术研究中心 富阳 311400;
    2. 安顺学院 安顺 561000;
    3. 浙江省淳安县姥山林场 淳安 311700
  • 收稿日期:2015-05-25 修回日期:2016-05-30 出版日期:2016-08-25 发布日期:2016-09-19
  • 通讯作者: 周志春
  • 基金资助:
    “十二五”国家科技支撑计划项目(2012BAD01B02);国家自然科学基金项目(31370671);浙江省农业新品种选育重大科技专项竹木育种协作组重点项目(2012C12908-12);贵州省科学技术厅、安顺市人民政府、安顺学院联合科技基金资金(黔科合LH字[2014]7497)。

Effects of Simulated Continuous N Sedimentation on the Ectomycorrhizal Symbiosis and soil Nutrients of 2-Year-Old Pinus massoniana Seedlings Under Low P Stress

Pang Li1,2, Zhou Zhichun1, Zhang Yi1, Feng Zhongping3   

  1. 1. Key Laboratory of Tree Breeding of Zhejiang Province Engineering Research Center of Masson Pine of State Forestry Administration Research Institute of Subtropical Forestry, CAF Fuyang 311400;
    2. Anshun University Anshun 561000;
    3. Laoshan Forest Farm of Chun'an County, Zhejiang Province Chun'an 311700
  • Received:2015-05-25 Revised:2016-05-30 Online:2016-08-25 Published:2016-09-19

摘要: [目的]研究低P胁迫下N沉降持续增加对马尾松菌根化苗木生长和土壤养分的影响,为有效调控以充分发挥菌根潜力提高苗木对土壤P表的吸收、利用效率提供理论依据。[方法]以马尾松优良家系为试材,设置持续2个生长季的N沉降与同质低P (介质表层与底层均缺P)、异质低P (介质表层P丰富、底层缺P)耦合条件下菌根共生的盆栽试验,量化分析不同低P胁迫下持续N沉降对马尾松菌根化苗木生物量积累、根系发育、N和P效率以及菌根土养分等的影响。[结果]1)同质低P下,土壤中N素累积、P素相对严重匮缺,从而显著抑制马尾松苗木的菌根侵染,降低菌根化苗木的生物量积累;异质低P下,土壤原有的N/P改变,从而促进菌根真菌对马尾松苗木的侵染及植株对N和P素的吸收,最终促进苗木生物量的增加。2)同质低P下,植株的N/P显著增加,导致苗木生长受P素的限制,而对N素的增加不敏感,从而抑制菌根化苗木的生长;异质低P下,持续的N输入增加菌根作用的有效性,促进苗木对土壤P素和N素的吸收,植株N/P降低,从而改善苗木的生长状况。3)同质低P下,菌根土养分状况改善,土壤N和P含量均增加,pH值未显著改变,这可能因为菌根对土壤作用的有效性增加;异质低P下,接种菌根菌对土壤养分的抑制程度降低,土壤pH值显著降低。[结论]2种P素环境下,菌根作用的有效性对持续增加的N沉降的响应不同:同质低P下,菌根土养分状况得以改善,但随着土壤有效N的不断累积,导致土壤P素相对严重匮缺,植株N/P显著增加,使苗木生长受P素的限制程度增加,最终抑制苗木的生长;异质低P下,持续N沉降降低菌根菌对土壤养分的抑制程度,改变土壤原有的N/P,增加菌根作用的有效性,最终显著增加苗木的生物量。

关键词: 马尾松, 低P胁迫, 持续N沉降, 菌根共生, P效率, 土壤养分

Abstract: [Objective] The increased atmospheric N sedimentation in recent years has brought the increased N availability and N/P ratio in forest soil, which would impact growth and P efficiency of mycorrhizal symbiosis plants. This study investigated effects of continuous N sedimentation on the ectomycorrhizal symbiosis of Pinus massoniana seedlings under low P stress to provide a theoretical basis for exerting the mycorrhizal potential to improve efficiency of Masson Pine P and growth.[Method] An elite breeding population of P. massoniana was used as test materials, two P conditions (homogeneous low P and heterogeneous low P among soil layers) and two N sedimentation levels were simulated in a pot experiment.[Result] 1) Under different P environments,,there were different responses of 2-year-old mycorrhizal seedlings to sustainable increase of N sedimentation. Under the homogeneous low P condition, N sedimentation significantly reduced the mycorrhizal infection rate and degree of P. massoniana seedlings, and inhibited the growth and P absorption efficiency of P. massoniana mycorrhizal seedlings, resulting in a significant reduction of P. massoniana biomass. Under the heterogeneous low P condition, simulated continuous N sedimentation increased seedlings mycorrhizal infection rate and degree, promoted the plant absorption of N and P, and thereby increased the seedlings biomass accumulation. 2) Under the homogeneous low P condition, N sedimentation significantly increased the plant N/P ratio, by which the seedlings growth was limited by P element, but was not sensitive to the increase of N. Under the heterogeneous low P condition, continuous N sedimentation improved the effectiveness of mycorrhizal effect and promoted the seedlings P and N absorption, and thus improved the seedlings growth. 3) Under the homogeneous low P condition, N sedimentation improved the nutrient status of mycorrhizal soil. Soil N and P levels were increased, but pH values did not change significantly. This was due to increase in the mycorrhizal effectiveness. Under the heterogeneous low P condition, simulated continuous N sedimentation reduced the inhibition degree of inoculation mycorrhiza fungi on soil nutrients, but soil pH value decreased significantly.[Conclusion] The effectiveness of mycorrhizal effect had different responses to increased N sedimentation under two P environment. Under the homogeneous low P condition, the effectiveness of the mycorrhiza effect increased. The status of soil nutrient was improved, but with the steady accumulation of soil effective N, soil P element was relatively serious deficiency. With the significantly increased plant N/P ratio, the limited degree of seedlings growth by P element was increased. Under the heterogeneous low P condition, the continuous N sedimentation reduced the limited degree of soil nutrient by mycorrhizal, thus the mycorrhizal fungi infection of the seedlings was promoted. Ultimately the accumulation of seedling biomass was increased.

Key words: Pinus massoniana, low P stress, continued N sedimentation, ectomycorrhizal symbiosis, P efficiency, soil nutrient

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