北极新奥尔松地区可溶性无机氮盐对根际土壤细菌群落多样性的影响

EFFECTS OF SOLUBLE INORGANIC NITROGEN SALTS ON DIVERSITY OF RHIZOSPHERE SOIL BACTERIAL COMMUNITY IN NY-ÅLESUND, ARCTIC

氮是植物生长的主要营养限制因子,为了探索北极近岸地区植物根际土壤细菌群落多样性受氮元素的影响作用,采用16S rDNA扩增子测序分析了2014—2016年新奥尔松地区(Ny-Alesund,Arctic)的3种典型植物根际土壤和本底土壤样品。结果显示,可溶性无机氮盐(NO_(2)^(-)-N,NO_(3)^(-)-N,NH_(4)^(+)-N)与3种植物根际土壤整体细菌群落呈显著相关性(P<0.05)。Nitrosomonadaceae_uncultured(P<0.05,r^(2)=-0.77)和Subgroup 6_norank(P<0.01,r^(2)=-0.87)是北极柳根际土壤的核心优势类群,与NO_(2)^(-)-N密切相关。Subgroup 6_norank(P<0.01,r^(2)=-0.92)和JG34-KF-361_norank(P<0.05,r^(2)=0.73)与珠芽蓼根际土壤的NO_(3)^(-)-N显著相关。抬头地杨梅根际土壤中的Acidimicrobiales_norank(P<0.05,r^(2)=-0.74)和Anaerolineaceae_uncultured(P<0.01,r^(2)=0.93)与NH_4^(+)-N有明显的相关性。研究表明,可溶性无机氮盐对北极植物根际土壤细菌群落多样性尤其是核心菌群的变化起到重要作用。

In recent years,global climate change has become increasingly serious,with a wide range of impacts.The polar regions are the earliest to respond to the impacts of climate change.Global climate change has led to the rapid growth of dominant plants such as vascular plants and graminoids in the Arctic.Salix arctica,Bistorta vivipara and Luzula confuse are the three most common dominant species in Ny-Ålesund(Arctic),which are potentially important for the composition and distribution of bacterial communities in the Arctic soil ecosystem.Microorganisms are highly sensitive to environmental changes,but also play a crucial role in the global carbon and nitrogen cycles and polar ecosystems balance.Nitrogen is one of the main nutrient limiting factors for plant growth.In order to study the effect of nitrogen on bacterial community diversity in plant rhizosphere soil in Arctic coastal area,16S rDNA amplicon sequencing was used to analyze the diversity of bacterial community in three typical types of plant rhizosphere soil and background soil in Ny-Ålesund(Arctic)from 2014 to 2016.The results showed that the soluble inorganic nitrogen(NO_(2)^(-)-N,NO_(3)^(-)-N,NH4+-N)was significantly correlated with the bacterial community in the rhizosphere soil of the three plants(P<0.05).Nitrosomonadaceae_uncultured and Subgroup 6_norank are the dominant core groups of Salix arctica rhizosphere soil,which have a significant correlation with NO_(2)^(-)-N(P<0.05).Subgroup 6_norank and JG34-KF-361_norank(Rhizobiales)show a significant correlation with NO_(3)^(-)-N(P<0.05)in rhizosphere soil of Bistorta vivipara.Acidimicrobiales_norank and Anaerolineaceae_uncultured have a significant correlation with NH_(4)^(+)-N(P<0.05)in rhizosphere soil of Luzula confuse.Furthermore,concentration of three soluble inorganic nitrogen salts and relative abundance of these core groups show consistent interannual variability.It can be seen that soluble inorganic nitrogen plays an important role in the diversity of bacterial community,especially the change of core bacterial community in the rhizosphere soil of Arctic plants.