Rice straw decomposition affects diversity and dynamics of soil fungal community, but not bacteria
Rice straw decomposition affects diversity and dynamics of soil fungal community, but not bacteria
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稻草分解影响土壤真菌群落的多样性和动态，但不影响细菌
DOI：
10.1007/s11368-017-1749-6
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发表时间：
2018-01-01
影响因子：
3.6
通讯作者：
Tang, Xueming
中科院分区：
文献类型：
--
作者：
Li, Peng;Li, Yongchun;Tang, Xueming
目的秸秆分解增加了土壤有机碳含量，改变了土壤微生物生物量。但是，在田间条件下，稻草分解对细菌和真菌群落组成演替的不同影响还知之甚少。本研究的目的是研究田间条件下稻草分解过程中土壤细菌和真菌群落的演变，以及土壤理化性质与微生物群落演变的关系。（90、180、270和360天），包括秸秆腐解土和对照（未腐解土）。从每个处理的三个重复小区的散装土壤样品（0-15厘米深）收集的土壤性质和微生物多样性参数的分析。采用PCR-变性梯度凝胶电泳（DGGE）和定量PCR（qPCR）技术对土壤细菌和真菌的群落结构和种群数量进行了研究。利用Shannon-Wiener多样性指数、丰富度和均匀度等参数对细菌和真菌群落多样性进行了评价。结果与讨论结果表明，与细菌相比，在稻草分解的不同时间点，土壤真菌种群数量和多样性指数均显著增加，在360 d时达到最大值。与细菌DGGE图谱相比，秸秆腐解土壤和对照土壤中真菌DGGE图谱发生了显著变化，土壤真菌优势属也发生了明显变化。从DGGE主要条带中获得细菌16 SrRNA（rRNA）和真菌18 SrRNA基因序列，，和枝顶孢属Acremonium sp.具有降解纤维素的能力。RDA结果表明，土壤有效P、有机C、pH和容重是影响稻草分解过程中真菌群落结构变化的主要因素。但在细菌群落中没有观察到这种发现。与对照相比，通过qPCR测量的真菌与细菌的比率在秸秆分解土壤中更高，表明真菌在秸秆分解中占主导地位。特别是，我们的研究推断，丰富多样的纤维素分解真菌属的稻草分解土壤中高度挖掘新的纤维素分解酶的潜力很大。
PurposeStraw decomposition increased amounts of soil organic carbon and changed microbial biomass. But the different impacts of rice straw decomposition on the succession of bacterial and fungal community composition in field conditions were poorly understood. The objective of this study was to investigate the development of soil bacterial and fungal communities during rice straw decomposition in field conditions, and the relationship between soil chemical/physical properties and the evolution of microbial communities.Materials and methodsA 1-year field study (90, 180, 270, and 360 days) was conducted, including the straw decomposition soil and control (no straw decomposition soil). The bulk soil samples (0–15-cm depths) from three replicate plots per treatment were collected for the analysis of soil properties and of microbial diversity parameters. Soil bacterial and fungal community structures and population sizes were determined by applying PCR-denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR). The bacterial and fungal community diversity was evaluated using the following parameters: Shannon–Wiener diversity index, richness, and evenness. Moreover, the relationship between soil properties and the changes of microbial communities was analyzed using redundancy analysis (RDA).Results and discussionThe results showed that, in contrast to bacteria, the soil fungal population size and diversity indices were significantly increased during different time points of rice straw decomposition, and reached to the highest value at 360 days. When compared with the bacterial DGGE profiles, the fungal DGGE profiles significantly changed between the straw decomposition soil and control, and the dominant soil fungal genera varied apparently. Bacterial 16Sribosomal RNA (rRNA) and fungal 18SrRNA gene sequences obtained from the main DGGE bands were further sequenced, among whichPenicilliumsp.,Aspergillussp., andAcremoniumsp. have the ability to degrade cellulose. RDA suggested that the soil available P, organic C, pH, and bulk density were the main factors influencing the variation in the fungal community structures and diversities.ConclusionsThe fungal community structures displayed distinct successions during rice straw decomposition. But such finding was not observed in bacterial communities. The ratio of fungi to bacteria measured by qPCR was higher in the straw decomposition soil compared with the findings in control, indicating that fungi predominated in straw decomposition. Especially, our study deduced that the diversified cellulolytic fungal genera highly enriched in rice straw decomposition soils had great potential of mining novel cellulose-decomposing enzymes.