摘要
重金属长期存在于土壤中,会对土壤微生物的生长、代谢产生影响,从而引起微生物群落结构的变化。为探究不同程度重金属污染对土壤细菌群落组成的影响,本研究以金川区农田铜镍污染土壤(Cu^(2+)、Ni^(2+)含量分别为261.1 mg/kg、258.2 mg/kg,pH为8.3)为研究对象,以耐铜镍植物卢塔纳鹰嘴紫云英(Astragalus cicer cv.Lutana)为供试材料,在温室采用盆栽试验法,研究铜、镍不同浓度复合溶液(0、100、200、400、800、1600 mg/kg)处理对根际土壤理化性质、生物学特性及根际细菌群落结构分布情况的影响。结果表明,随铜镍复合胁迫浓度的升高,根际土壤水分含量、Cu^(2+)和Ni^(2+)含量均升高;速效氮、磷、钾含量、微生物量碳、氮、磷含量、有机质含量及Chao 1指数、Pielou指数、Shannon指数和Simpson指数均先升后降,其中除速效钾外,其余指标均在铜镍胁迫浓度为100 mg/kg时达到最高;根际土壤pH值、脲酶、过氧化氢酶、脱氢酶和碱性磷酸酶活性均下降;优势菌门主要有变形菌门、酸杆菌门、放线菌门、拟杆菌门和芽单胞菌门;除变形菌门以外,随铜镍胁迫浓度升高,芽单胞菌门和拟杆菌门的相对丰度呈显著上升,而酸杆菌门的相对丰度先增后降,放线菌门的相对丰度显著下降。冗余分析和蒙特卡洛置换检验结果显示,脱氢酶、pH和微生物量氮是根际土壤细菌群落结构变化的主导因子。在铜镍胁迫浓度为100 mg/kg时可提高根际细菌群落多样性,在100 mg/kg以上会抑制根际细菌群落多样性。
Heavy metals persist in soil,impacting the growth and metabolism of soil microorganisms,leading to shifts in microbial community structure.This study investigated the influence of varying copper(Cu)and nickel(Ni)levels on the composition of bacteria in a Cu-Ni polluted farmland soil(Jinchuan District,pH 8.3,Cu^(2+)261.1 mg/kg,Ni^(2+)258.2 mg/kg).The copper-nickel-resistant plant Astragalus cicer cv.Lutana was employed as the test material.A greenhouse pot experiment was conducted to examine the effects of different Cu-Ni solution concentrations(0,100,200,400,800,and 1600 mg/kg)on the biological characteristics,physical and chemical properties,and the distribution of bacterial community structure in the rhizosphere soil of A.cicer.The results showed that increasing Cu-Ni stress concentrations significantly increase rhizosphere soil moisture,Cu^(2+)and Ni^(2+)contents.Available nitrogen,phosphorus,potassium,microbial biomass carbon,nitrogen,and phosphorus,organic matter,as well as Chao 1 richness index,Pielou evenness index,and Shannon and Simpson diversity indices displayed an initial increase followed by a decrease with increasing stress,and the indicators but available potassium reached their peak at 100 mg/kg Cu-Ni.Conversely,pH value,urease,catalase,dehydrogenase,and alkaline phosphatase activities in the rhizosphere soil all exhibited a reduction with increasing stress.Proteobacteria,Acidobacteria,Actinobacteria,Bacteroidetes,and Gemmatimonadetes emerged as the dominant bacterial groups across all samples.Relative abundances of Gemmatimonadetes and Bacteroidetes increased with rising Cu-Ni concentrations,while the relative abundance of Acidobacteria displayed an initial increase followed by a decrease.Actinobacteria relative abundance showed a decline.Redundancy analysis and the Monte Carlo permutation test revealed significant impacts of soil dehydrogenase,pH,and microbial biomass nitrogen on the bacterial community composition.In conclusion,a Cu-Ni concentration of 100 mg/kg appeared to promote the diversit
作者
姚宇恒
李景峰
南丽丽
郭全恩
曹诗瑜
YAO Yuheng;LI Jingfeng;NAN Lili;GUO Quanen;CAO Shiyu(College of Pratacultural Science,Gansu Agricultural University/Key Laboratory of Grassland Ecosystem,Ministry of Education,Lanzhou 730070,China;Soil Fertilizer and Water-Saving Institute,Gansu Academy of Agricultural Sciences,Lanzhou 730070,China)
出处
《中国草地学报》
CSCD
北大核心
2024年第4期90-99,共10页
Chinese Journal of Grassland
基金
国家自然科学基金项目(32160327)
甘肃省科技计划项目(22YF7NA112)
财政部和农业农村部:国家现代农业产业技术体系项目(CARS-34)共同资助。
关键词
铜镍胁迫
根际土壤
细菌
土壤微生物量
土壤酶
Cu-Ni stress
Rhizosphere soil
Bacteria
Soil microbial biomass
Soil enzymes
