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林业科学 ›› 2021, Vol. 57 ›› Issue (4): 163-172.doi: 10.11707/j.1001-7488.20210417

• 研究简报 • 上一篇    下一篇

大气CO2浓度升高对宁夏枸杞根区土壤微生物功能多样性及碳源利用特征的影响

谢云,郭芳芸,陈丽华,曹兵*   

  1. 宁夏大学农学院 银川 750021
  • 收稿日期:2020-01-06 出版日期:2021-04-01 发布日期:2021-05-21
  • 通讯作者: 曹兵
  • 基金资助:
    国家自然科学基金项目(31660199)

Effects of Elevated CO2 Concentration on Soil Microbial Functional Diversity and Carbon Source Utilization Characteristics in the Root Zone of Lycium barbarum

Yun Xie,Fangyun Guo,Lihua Chen,Bing Cao*   

  1. College of Agriculture, Ningxia University Yinchuan 750021
  • Received:2020-01-06 Online:2021-04-01 Published:2021-05-21
  • Contact: Bing Cao

摘要:

目的: 分析大气CO2浓度升高对宁夏枸杞根区土壤微生物功能多样性及碳源利用特征的影响,为宁夏枸杞适应气候变化进行可持续管理提供理论依据。方法: 以宁夏枸杞扦插苗为材料,采用开顶气室设置自然环境大气CO2浓度[CK,(400±20)μmol·mol-1]、0.5倍增[TR1,(600±20)μmol·mol-1]和1倍增[TR2,(800±20)μmol·mol-1]3个处理宁夏枸杞苗木,分别于处理后的30、60、90、120天采集根区土样,采用BIO-ECO技术分析土壤微生物群落功能多样性及碳源利用特征。结果: 1)CO2浓度升高均显著提高宁夏枸杞根区土壤微生物碳源代谢活性(AWCD),0.5倍增和1倍增大气CO2浓度AWCD分别比对照提高22.56%、36.45%。2)随着CO2浓度升高,土壤微生物Shannon指数、McIntosh指数显著增加,而Simpson指数在处理前期增加,但处理中后期无显著变化。3)宁夏枸杞根区土壤微生物群落利用并转化的主要碳源为氨基酸类、酯类和胺类碳源;CO2浓度升高处理下,土壤微生物利用率较大的碳源主要为酯类和胺类,而糖类和酸类利用率较低。其中1倍增大气CO2浓度下土壤微生物群落对L-精氨酸、L-天冬酰胺酸、吐温-40、苯乙基胺和4-羟基苯甲酸等的利用代谢能力均显著高于对照,但对γ-羟基丁酸的利用代谢能力显著低于对照。4)大气CO2浓度升高显著影响宁夏枸杞根区土壤微生物群落碳源利用率,不同时期将土壤微生物群落划分而起分异作用的主要碳源是糖类和胺类。结论: 大气CO2浓度升高能使微生物群落的活性及碳源利用率明显增加,并且均提高宁夏枸杞根区土壤微生物群落的物种丰富度、物种优势度及群落均匀度,1倍增大气CO2浓度处理土壤微生物群落代谢活性和多样性最高,六大类碳源中,氨基酸类、酯类和胺类碳源是宁夏枸杞根区土壤微生物群落利用并转化的主要碳源。处理60天时(7月份)土壤微生物群落碳源利用率最强。因此,大气CO2浓度升高是造成宁夏枸杞根区土壤微生物群落代谢多样性和碳源利用差异的主要原因。

关键词: 大气CO2浓度升高, 宁夏枸杞, 土壤微生物群落, BIO-ECO, 碳源利用特征

Abstract:

Objective: This paper studied the differences in the functional diversity and carbon source utilization characteristics of soil microorganisms in the root zone of Lycium barbarum, by which determined the effects of doubled CO2 concentration on the functional diversity of soil microorganisms in the root area of L. barbarum, so as to provide theoretical basis for sustainable management of L. barbarum. Method: In this study, the cuttings of L. barbarum(wolfberry) were used as materials. An open-top chamber (OTC) was used to set three CO2 concentration gradients of atmospheric CO2 concentration (CK, 400±20 μmol·mol-1), and 1.5-time atmospheric CO2 concentration (TR1, 600±20 μmol·mol-1), and 2-time atmospheric CO2 concentration(TR2, 800±20 μmol·mol-1). The wolfberry saplings were subjected to the different CO2 concentrations. Soil samples were collected from the root zone at 30, 60, 90, and 120 days after treatment and analyzed by BIO-ECO technology for the functional diversity of soil microbial communities and the characteristics of carbon source utilization. Result: 1) The microbial carbon source metabolic activity (AWCD) in the root zone of L. barbarum significantly increased with the increase of CO2 concentration. Compared with the control, the AWCD of 1.5-time and 2.0-time atmospheric CO2 concentration increased by 22.56% and 36.45%, respectively. 2) With the increase of CO2 concentration, the Shannon index and McIntosh index of soil microorganisms increased significantly. The Simpson index increased in the early stages of treatment, but there was no significant change in the middle and late stage of treatment. 3) The main carbon source of the soil microbial community in Ningxia wolfberry root zone was amino acids, esters and amines. Under the elevated CO2 concentration, the carbon sources with higher soil microbial utilization rate were mainly esters and amines, while the utilization rate of sugars and acids was lower. Under 2.0-time atmospheric CO2 concentration, the utilization and metabolism of L-arginine, L-asparaginic acid, Tween-40, phenethylamine, and 4-hydroxybenzoic acid were significantly higher than that of the control, but the utilization and metabolism of γ-hydroxybutyric acid were significantly lower than that of the control. 4) The increase of atmospheric CO2 concentration significantly affected the utilization of carbon sources in the soil microbial community in the root zone of wolfberry. Sugars and amines were the main carbon sources that differentiated the soil microbial community in different periods. Conclusion: Elevated CO2 concentration can significantly increase the activity of microbial communities and the utilization of carbon sources, and all increase the species richness, species dominance, and community uniformity of soil microbial communities in the root zone of wolfberry. The highest metabolic activity and diversity of soil microbial community treated with one time increase of atmospheric CO2 concentration were found. Among the six major types of carbon sources, amino acid, ester and amine carbon sources are the main carbon sources utilized and transformed by the soil microbial community in the root zone of wolfberry. The carbon source utilization rate of soil microbial community is the strongest at 60 days (July). Therefore, the increase of atmospheric CO2 concentration is the main reason for the differences in the metabolic diversity and carbon source utilization of soil microbial communities in the root zone of Lycium barbarum.

Key words: elevated CO2concentration, Lycium barbarum, soil microbial community, BIO-ECO, carbon source utilization characteristics

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