利用gamma辐射结合交叉混合土壤构建土壤线虫多样性梯度  

Constructing nematode diversity gradient using soil sterilization by gamma radiation and soil cross-mixing

作　　者：李钰飞[1] 孙钦平[1] 李吉进[1] 许俊香[1] 郎乾乾 赵祥 刘本生[1] LI Yufei;SUN Qinping;LI Jijin;XU Junxiang;LANG Qianqian;ZHAO Xiang;LIU Bensheng(Institute of Plant Nutrition,Resources and Environment,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,China)

机构地区：[1]北京市农林科学院植物营养与资源环境研究所,北京100097

出　　处：《生态学杂志》2023年第7期1705-1712,共8页Chinese Journal of Ecology

基　　金：北京市农林科学院青年科研基金(QNJJ202004);北京市农林科学院农业科技示范推广项目(2021703);财政部和农业农村部:国家现代农业产业技术体系(CARS-02)资助。

摘　　要：为探索一种全新的构建土壤生物多样性梯度的方法,本研究以土壤线虫群落为对象,利用gamma辐射灭活土壤再交叉混合的方法构建新组合土壤,分析新组合的土壤中线虫群落是否能保持明显差异以及新组合土壤的理化性状是否能保持一致。选择自然林地和临近的菜地2种土壤进行取样,设置3个处理开展盆栽试验,分别为:(1)未灭活菜地土混合未灭活林地土(FW);(2)灭活菜地土混合未灭活林地土(SFW);(3)灭活林地土混合未灭活菜地土(SWF)。结果表明,土壤pH、速效钾、有机质、电导率、有效磷、全氮和铵态氮在SFW和SWF之间均无显著差异,仅硝态氮含量在SWF中显著升高(P<0.05)。SFW的线虫分类单位数量、香农指数、营养类群多样性指数均显著高于SWF(P<0.05),而优势度指数呈现相反趋势。线虫功能指数如瓦斯乐斯卡指数、线虫通路比、成熟指数、总成熟指数、通道指数和结构指数在SFW和SWF中均表现出不同程度的显著差异(P<0.05)。主成分分析显示,各处理的线虫群落差异明显,并且FW介于SFW和SWF之间。总体上,利用gamma辐射灭活土壤再交叉混合的方法可有效构建线虫多样性梯度,并保持新组合的土壤之间理化性状基本一致。The construction of soil biodiversity gradient is a key step to examine the relationship between biodiversi-ty and ecological function in the underground ecosystem.Previous methods used to construct soil biodiversity gradi-ent are lack of wholeness.In this study,we proposed a new method that mixed the un-sterilized and sterilized soil with gamma radiation.Soil nematode community was used as model community because it covers several trophic levels.We determined whether soil nematode community in different cross-mixing soils could maintain significant biodiversity differences,and whether soil properties could be consistent in different soils.Soils were collected from a natural woodland and an adjacent vegetable field.A greenhouse pot experiment was conducted with three treat-ments:(1)original vegetable field soil mixed with original woodland soil(FW);(2)sterilized vegetable field soil mixed with original woodland soil(SFW);(3)sterilized woodland soil mixed with original vegetable field soil(SWF).The results showed that there were no significant differences in soil pH,available potassium,organic mat-ter,electrical conductivity,available phosphorus,total nitrogen and ammonium nitrogen between SFW and SWF,but soil nitrate nitrogen content in SWF was significantly higher than that of the other treatments(P<0.05).Bacteri-vores were predominant in SWF,accounting for more than 90%of the total population,while in SFW,bacteri-vores,and herbivores were dominant.The number of nematode taxa,Shannon index and trophic group diversity in SFW were significantly higher than those in SWF(P<0.05),whereas the dominance index showed an opposite trend.Nematode function index such as Wasilewska index,nematode channel ratio,maturity index,sigma maturity index,channel index and structure index showed significant differences between SFW and SWF.Results of princi-pal component analysis showed that soil nematode communities were clearly different among the three treatments.In conclusion,this new method could effectively construct a nematode d

关 键 词：土壤食物网 生物多样性 调控 土壤灭活 gamma辐射 

分 类 号：S154.386[农业科学—土壤学]