氧气对水稻土N_(2)O排放和narG型反硝化微生物的短期影响  

Short-term effects of the oxygen on N_(2)O emissions and narG type denitrifying microbes in paddy soils

作　　者：姚东良 彭德元 王振华 秦红灵[3] 刘毅[3] 张俊忠[1,4] YAO Dongliang;PENG Deyuan;WANG Zhenhua;QING Hongling;LIU Yi;ZHANG Junzhong(College of Biodiversity Conservation,Southwest Forestry University,Kunming,Yunnan 650224,China;Zhangjiajie City Company,Hunan Tobacco Company,Zhangjiajie,Hunan 427099,China;Key Laboratory of Agro-ecological Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha,Hunan 410125,China;Key Laboratory of Forest Disaster Warning and Control in Yunnan Province,Kunming,Yunnan 650224,China)

机构地区：[1]西南林业大学生物多样性保护学院,云南昆明650224 [2]湖南省烟草公司张家界市公司,湖南张家界427099 [3]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,湖南长沙410125 [4]云南省森林灾害预警与控制重点实验室,云南昆明650224

出　　处：《湖南农业大学学报（自然科学版）》2023年第3期335-343,共9页Journal of Hunan Agricultural University(Natural Sciences)

基　　金：湖南省自然科学基金面上项目(2022JJ30647、2020JJ4654);湖南创新型省份建设专项经费(2021NK2028);云南省教育厅科学研究基金项目(2022J0512);湖南省烟草公司张家界市公司项目(202103)。

摘　　要：选取第四纪红土发育水稻土,在0%(厌氧)、10%(兼性厌氧)和21%(好氧)等3个O_(2)体积分数及40%和60%2种土壤含水量条件下进行室内培养,探讨O_(2)含量对土壤N_(2)O排放及narG型反硝化微生物种群丰度和群落组成的影响。结果表明:40%和60%2种土壤含水量条件下,厌氧处理的N_(2)O排放通量均最高,且60%土壤含水量处理下的N_(2)O排放通量略高于40%土壤含水量处理的;方差分析表明,相比于土壤含水量,O_(2)含量是制约土壤中N_(2)O排放更关键的因子;微生物narG基因丰度与O_(2)含量呈极显著(P<0.01)负相关,与N_(2)O排放通量和土壤NO_(3)^(–)–N消耗质量分数呈极显著(P<0.01)正相关,与土壤含水量呈正相关,但不显著;O_(2)含量和含水量均会造成土壤narG型反硝化微生物群落组成差异,40%土壤含水量处理,OTU1882(Pseudolabrys)、OTU1510(分枝杆菌属)的占比较大,60%土壤含水量处理,OTU1593(地杆菌属)的占比较大,当土壤含水量一定时,同一培养时间厌氧处理的优势OTU1882和OTU1510相对丰度偏低,且变化幅度较大,其相对丰度与N_(2)O排放通量呈负相关,其中OTU1882的影响显著(P<0.05)。可见,土壤O_(2)含量通过调控土壤微生物的narG基因丰度和群落组成而调控N_(2)O的排放。To investigate the effect of soil O2 concentration on soil N_(2)O emission and the abundance and composition of narG type denitrifying microbes in paddy soils,the quaternary red clay was incubated under three O_(2) concentrations of 0%(anaerobic),10%,and 21%,and two soil water contents of 40%and 60%.The results showed that under both 40% and 60% soil moisture conditions,anaerobic treatment had the highest N_(2)O emission flux,and the N2O emission flux under 60% soil moisture treatment was slightly higher than that under 40% soil moisture treatment.The analysis of variance indicated compared with soil water content,O_(2) was more important factor restricting N_(2)O emissions in the soil.The abundance of narG gene of soil microbes was negatively correlated with O_(2) content(P<0.01),positively correlated with N_(2)O emission flux and soil NO_(3)^(–)-N consumption mass fraction(P<0.01),and positively correlated with soil moisture content,but not significantly.Both O2 content and soil moisture content could cause the difference in composition of narG type denitrifying microbial community.In the 40%soil moisture treatment,OTU1882(Pseudolabs)and OTU1510(Mycobacterium)accounted for a larger proportion,while in the 60%soil moisture treatment,OTU1593(Geobacter)accounted for a larger proportion.When the soil moisture content was constant,the relative abundances of advantages OTU1882 and OTU1510 in anaerobic treatment at the same time were relatively low,and the variation amplitude were large,which were negatively correlated with N2O emission flux with a significant(P<0.05)effect for OTU1882.In summary,soil O2 content could regulate N2O emissions by regulating the abundance of narG gene and community composition of soil microbe.

关 键 词：水稻土 narG型反硝化微生物 氧气 土壤含水量 N2O排放 

分 类 号：S154.1[农业科学—土壤学]