PCR-DGGE技术解析针叶和阔叶凋落物混合分解对土壤微生物群落结构的影响  

Analyzing the Effect of Mixed Decomposition of Conifer and Broadleaf Litters on Soil Microbial Communities by Using PCR-DGGE

作　　者：陈法霖[1] 张凯[1] 郑华[1] 林学强[2] 欧阳志云[1] 屠乃美[3] 

机构地区：[1]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [2]海南省环境科学研究院,海口570206 [3]湖南农业大学农学院,长沙410128

出　　处：《应用与环境生物学报》2011年第2期145-150,共6页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(Nos.40871130;30600474)资助~~

摘　　要：为深入理解凋落物类型和微生物群落之间的相互关系,通过小盆+凋落袋控制实验,运用PCR-DGGE技术解析了南方红壤丘陵区典型针叶树种马尾松和湿地松的凋落物分别与白栎、青冈两个阔叶树种凋落物混合分解对土壤微生物基因型多样性的影响.结果表明:1)针叶凋落物中加入阔叶后细菌群落结构未发生显著变化,将所有处理归为一类的相似度达72%,其差异仅表现在马尾松+白栎和湿地松+青冈处理土壤微生物群落16S rDNA的丰富度和多样性分别显著高于单一马尾松和湿地松;2)针叶凋落物中加入阔叶后真菌群落结构发生了显著变化,单一针叶处理与针阔混合处理间18S rDNA基因泳道带型的相似度只有28%,并且单一马尾松处理土壤18S rDNA的丰富度和多样性显著高于马尾松+白栎和马尾松+青冈,单一湿地松处理土壤18S rDNA的丰富度也显著高于湿地松+白栎和湿地松+青冈,多样性显著高于湿地松+白栎处理;3)土壤真菌18S rDNA的丰富度与凋落物初始C含量呈显著正相关,与凋落物初始N含量呈显著负相关.针叶凋落物中引入阔叶凋落物后,增加了凋落物中N的比重,C的比重则下降,显著影响了土壤真菌群落的结构.Clarifying the microbiological mechanism of litter decomposition is of great significance,especially in understanding how the soil microbial communities affect the decomposition of mixed litters with conifer and broadleaf trees.In this study,a simulation experiment was designed with flowerpots,and the litters of the typical species in the southern hilly red soil region,including Pinus massoniana（PM）,Pinus elliottii（PE）,Quercus fabri（QF） and Cyclobalanopsis glauca（CG）,were investigated as study materials.The effects of the decomposition of the mixed litters on the genotypic diversity of soil microbial communities were studied by using PCR-DGGE method.The results indicated： 1） No significant change occurred in bacterial community structure and the lowest similarity was 72% if all treatments were graded as one class after mixing broadleaf litter with conifer litter.The differences were that the richness and diversity of 16S rDNA in PM＋QF and PE＋CG were significantly higher than that of single-conifer litter of PM and PE,respectively;2） Fungal community structure significantly changed and the similarity between the single-conifer litter treatment and the mixed litter treatment was only 28%.The richness and diversity of 18S rDNA in PM were significantly higher than those of PM＋CG.The richness of 18S rDNA in PE was also significantly higher than that of PE＋QF and PE＋CG,and the diversity was significantly higher than that of PE＋QF;3） The richness of 18S rDNA was positively related with initial carbon content of litter,but significantly negative with initial nitrogen content of litter.After mixing broadleaf litter with conifer litter,the proportion of nitrogen in litters increased,but the proportion of carbon declined significantly,which significantly affected the soil fungal community structure.

关 键 词：森林凋落物 混合分解 土壤微生物 群落结构 16S RDNA 18S RDNA 多样性 DGGE 

分 类 号：S714.336[农业科学—林学]