亚热带主要造林树种土壤氮保留及相关功能的微生物特征  

Characteristics of Soil nitrogen Retention and Related Functional Microorganism in Soils of Main Afforestation Species in Subtropical Region

作　　者：王磊 梁艺凡[1] 杨军钱 张冰冰 王涛[1] 施秀珍 胡行伟 黄志群[1] Wang Lei;Liang Yifan;Yang Junqian;Zhang Bingbing;Wang Tao;Shi Xiuzhen;Hu Hangwei;Huang Zhiqun(Fujian Normal University,State Key Laboratory for Subtropical Mountain Ecology School of Geographical Sciences,Fujian Normal University,Fuzhou 350007)

机构地区：[1]福建师范大学地理科学学院,福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福州350007

出　　处：《林业科学》2020年第8期27-37,共11页Scientia Silvae Sinicae

基　　金：国家杰出青年科学基金项目(31625007);国家自然科学基金项目(31741024);国家自然科学基金青年科学基金项目(41907022)。

摘　　要：【目的】探讨我国亚热带人工林主要造林树种对土壤氮循环相关功能微生物基因丰度和群落结构的影响,阐明土壤氮保留影响的微生物驱动机制的树种差异。【方法】对生长在酸性红壤上的5种人工林采用实时荧光定量PCR研究森林土壤的固氮微生物(nifH)、硝化微生物(AOA amoA、AOB amoA)、反硝化微生物(narG、nirK、nirS、nosZ)、真菌(ITS)和细菌(16S rRNA)基因丰度,通过建立克隆文库和测序,对AOA不同的末端限制性片段进行系统发育分析,通过采用末端限制性片段多态性技术(T-RFLP)分析AOA群落结构,研究各树种人工林土壤的保氮能力及相关功能微生物特征。【结果】1)5种人工林土壤pH值范围为4.63~4.82,木荷和火力楠林的土壤硝态氮含量显著高于闽楠和福建柏林(P<0.05),火力楠和木荷林土壤的微生物生物量(MBC、MBN)在5个人工林中均最高,而闽楠和杉木林的均最低;凋落物的木质素和纤维素含量显著抑制土壤微生物生物量;2)5种森林土壤的固氮微生物nifH基因丰度无显著差异。木荷林的AOA丰度显著高于闽楠、火力楠和福建柏林,木荷林的AOB丰度显著高于福建柏林,木荷林的AOA和AOB丰度均最高;在氨氧化微生物中,AOA/AOB>2,AOA在数量上占据优势地位。反硝化微生物的narG、nirK和nosZ丰度在树种间均无显著差异,木荷林土壤的nirS丰度显著高于火力楠、杉木和福建柏林。闽楠林土壤的真菌ITS丰度显著高于木荷林,土壤细菌16S丰度在树种间均无显著差异;3)Pearson相关分析发现,土壤pH值与AOB、narG、nosZ显著正相关,土壤NO3^--N含量与土壤AOA极显著正相关(P<0.01);4)系统发育分析显示,5种森林土壤AOA类群属于Nitrosopumilus和Nitrososphaera,使用HpyCH4V限制性内切酶对AOA amoA基因PCR产物进行酶切,能够产生4个TRFs,其中TRF-76和TRF-165是最主要的2个片段类型,分别占总片段的54.88%~100%、0~45.12%,TRF-76和TRF-165的相对丰度【Objective】In this study,five plantations of Phoebe bournei、Michelia macclurei、Schima superba、Cunninghamia lanceolata and Fokienia hodginsii in subtropical region of china were selected as the research objects.The mains purpose of this study aims to investigate effects of main afforestation species on gene abundance and community structure of soil nitrogen cycle-related functional microorganisms,and to elucidate the microbial driving mechanism of the effects of subtropical plantation species on soil nitrogen retention.【Method】For five kinds of plantation growing on acidic red soil,we applied real-time quantitative PCR to characterize the abundance of nitrogen-fixing microorganisms(nifH)、nitrifying microorganisms(AOA amoA,AOB amoA)、denitrifying microorganisms(narG、nirK、nirS、nosZ)、fungi(ITS)and bacteria(16S rRNA)in forest soils,Phylogenetic analysis of AOA different terminal restriction fragments(TRFs)was performed by cloning and sequencing,and the community structure of AOA was analyzed using Terminal restriction fragment length polymorphism fingerprints.The soil nitrogen retention ability and microbial characteristics of each tree species plantation were studied.【Result】1)The pH values of the soils of the five plantations ranged from 4.63 to 4.82.Soil nitrate nitrogen content of S.superba and M.macclurei forest was significantly higher than that of P.bournei and F.hodginsii forest(P<0.05).Soil microbial biomass of M.macclurei and S.superba forest was the highest in five plantations,while that of P.bournei and C.lanceolata forest was the lowest.Lignin and cellulose content in litter significantly inhibited soil microbial biomass;2)There was no significant differences in the nifH gene abundance between five plantations forest,the AOA abundance of S.superba forest was significantly higher than that of P.bournei,M.macclurei and F.hodginsii foreest.The AOB abundance of S.superba forest was significantly higher than that of F.hodginsii forest,and the gene abundances of AOA and AOB in S.sup

关 键 词：树种 土壤氮保留 功能基因丰度 Q-PCR T-RFLP 

分 类 号：S714[农业科学—林学]