豆科作物间作燕麦对土壤固氮微生物丰度和群落结构的影响  

Effects of legume-oat intercropping on abundance and community structure of soil N_2-fixing bacteria

作　　者：杨亚东[1] 冯晓敏[1,2] 胡跃高[1] 任长忠[3] 曾昭海[1] 

机构地区：[1]中国农业大学农学院,北京100193 [2]中国农业科学院作物科学研究所/农业部作物生理生态重点实验室,北京100081 [3]吉林省白城市农业科学院,吉林白城137000

出　　处：《应用生态学报》2017年第3期957-965,共9页Chinese Journal of Applied Ecology

基　　金：国家现代农业产业技术体系建设专项(CARS-08-B-1);公益性行业(农业)科研专项(201503121-11;201503120)资助~~

摘　　要：利用荧光定量PCR和高通量测序的研究方法,比较了3种种植模式(燕麦单作,O;大豆/燕麦,OSO;绿豆/燕麦,OMO)对燕麦土壤固氮微生物数量和群落组成的影响.结果表明:与大豆和绿豆间作显著改变了燕麦土壤的理化性质.燕麦土壤固氮微生物nif H基因拷贝数为每克干土1.75×10^(10)~7.37×10^(10),拔节期和成熟期OSO和OMO中nif H基因拷贝数分别是O中的2.18、2.64和1.92、2.57倍,且各处理成熟期nif H基因拷贝数显著低于拔节期.样品稀释性曲线和覆盖度结果表明,各样品nif H基因测序结果可靠.与绿豆间作显著提高了燕麦土壤nif H基因的多样性.各样品固氮微生物属水平上优势类群均为Azohydromonas、固氮菌属、慢生根瘤菌属、Skermanella和在属水平上无法归类的固氮微生物,但各优势类群相对丰度存在差异.样品OTU的venn分布和主成分分析显示,拔节期和成熟期nif H基因群落结构存在差异,两个生育时期OSO和OMO具有更相似的nif H基因群落结构.表明与大豆和绿豆间作可显著提高燕麦土壤固氮微生物的数量,并影响固氮微生物的群落组成.In this study, real-time PCR and high-throughput sequencing approaches were employed to investigate the abundance and community structure of NE-fixing bacteria in a field experiment with three planting patterns （ Oat monocuhure, O ; Soybean-oat intercropping, OSO ; Mung beanoat intercropping, OMO）. The results showed that soil chemical properties varied significantly in different soil samples （P〈0.05）. The abundance of n/fH gene varied from 1.75× 10^10 to 7.37 ×10^10 copies · g-1 dry soil in all soil samples. The copy numbers of n/fH gene in OSO and OMO were 2.18, 2.64, and 1.92, 2.57 times as much as that in O at jointing and mature stages, with a significant decline from jointing to mature stage for all treatments （P〈0.05）. Rarefaction curve and coverage results proved the n/fH gene sequencing results were reliable, and the diversity index showed that the N2-fixing bacteria diversity of OSO was much higher than that of O. Azohydromonas, Azotobacter, Bradyrhizobium, Skermanella and other groups that could not be classified are the dominant genera, with significant differences in proportion of these dominant groups observed among all soil samples （P〈0.05）. Venn and PCA analysis indicated that there were greater differences of n/fH gene communities between jointing and mature stages; however, the OSO and OMO had similar communities in both stages. All these results confirmed that legume-oat intercropping significantly increased the abundance and changed the community composition of N2-fixing bacteria in oat soils.

关 键 词：豆禾间作 nif H基因 荧光定量PCR 高通量测序 群落组成 

分 类 号：S154.3[农业科学—土壤学] S344.2[农业科学—农业基础科学]