微生物学报  2020, Vol. 60 Issue (11): 2434-2449   DOI: 10.13343/j.cnki.wsxb.20200021.
http://dx.doi.org/10.13343/j.cnki.wsxb.20200021
中国科学院微生物研究所,中国微生物学会,中国菌物学会
0

文章信息

熊悯梓, 钞亚鹏, 赵盼, 宋双伟, 石莹莹, 莫乘宝, 仲乃琴. 2020
Xiong Minzi, Chao Yapeng, Zhao Pan, Song Shuangwei, Shi Yingying, Mo Chengbao, Zhong Naiqin. 2020
不同生境马铃薯根际土壤细菌多样性分析
Comparison of bacterial diversity in rhizosphere soil of potato in different habitats
微生物学报, 60(11): 2434-2449
Acta Microbiologica Sinica, 60(11): 2434-2449

文章历史

收稿日期:2020-01-08
修回日期:2020-04-22
网络出版日期:2020-07-02
不同生境马铃薯根际土壤细菌多样性分析
熊悯梓1 , 钞亚鹏2,3 , 赵盼2,3 , 宋双伟2,3 , 石莹莹1 , 莫乘宝4 , 仲乃琴2,3     
1. 宁夏大学农学院, 宁夏 银川 750021;
2. 中国科学院微生物研究所, 北京 100101;
3. 内蒙古自治区马铃薯肥料农药高效利用技术企业重点实验室, 内蒙古 呼伦贝尔 021000;
4. 广西壮族自治区环江毛南族自治县糖蔗生产技术服务站, 广西 河池 547100
摘要[目的] 为了探索马铃薯疮痂病发生与土壤环境的关系,分析区域性种植方式和施肥量对土壤细菌种群变化的影响,为实现土传病害有效防治提供借鉴。[方法] 本文分别从1年连作土传病害轻的宁夏西吉(西北)、3年连作土传病害严重的河北沽源(华北)、5年轮作未发现土传病害的内蒙古海拉尔(东北)大田马铃薯根际采集土壤,利用高通量测序技术,比较了样品间细菌群落结构差异。[结果] 3组样品共获得有效条带617558条,可分类操作单元(OTUs)3077个。各样品中变形菌门(Proteobacteria)数量最多,含量均在33%以上。与未发病土壤样品相比,土传病害发生严重的样品中细菌数量、物种数、细菌多样性、种类丰富度均有所降低,有害菌数量增加,益生菌数量减少。其中,放线菌(Actinobacteria)数量明显增多,变形菌(Proteobacteria)、绿弯菌(Chloroflexi)和酸杆菌(Acidobacteria)数量明显减少,组分及数量差异明显的细菌(尤其是放线菌门)大多与土壤全磷含量呈显著相关。[结论] 过量施用化肥和常年连作改变了土壤细菌群落结构,生态环境恶化,导致土传性病害发生。其中,磷可能是影响土壤微生物群落结构变化最主要的肥料元素。
关键词高通量测序    马铃薯    根际土壤    微生物多样性    
Comparison of bacterial diversity in rhizosphere soil of potato in different habitats
Xiong Minzi1 , Chao Yapeng2,3 , Zhao Pan2,3 , Song Shuangwei2,3 , Shi Yingying1 , Mo Chengbao4 , Zhong Naiqin2,3     
1. School of Agriculture, Ningxia University, Yinchuan 750021, Ningxia Hui Autonomous Region, China;
2. Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China;
3. The Enterprise Key Laboratory of Advanced Technology for Potato Fertilizer and Pesticide, Hulunbuir 021000, Inner Mongolia Autonomous Region, China;
4. Sugarcane Production Technical Service Station of Huanjiang Maonan Autonomous County, Hechi 547100, Guangxi Zhuang Autonomous Region, China
Abstract: [Objective] To monitor the changes of soil bacterial population due to different planting patterns and intensities of fertilization, analyze the relationship between occurrence of soil-borne diseases and change of soil-environment, provide theoretical basis for effectively controlling soil-borne diseases of potato. [Methods] Soil rhizosphere samples were collected from three distinct potato fields continuously cropped for one-year in Xiji (Ningxia, northwest), three-year in Guyuan (Hebei, north) and five-year in Hailar (Inner Mongolia, northeast) with low, high and rare incidence, respectively, of soil borne diseases. Then, high-throughput sequencing technology was used to comparably analyze the bacterial community structure and diversity of these samples. [Results] A total of 617558 effective reads and 3077 sortable operating units (OTUs) were obtained from the 3 groups of samples. Among them, the dominant component was Proteobacteria with a proportion over 33%. Compared with the soil samples from the field without occurrence of potato soil-borne diseases, the bacterial abundance and diversity decreased significantly in the soil samples from the field with high incidence of potato soil-borne diseases. Meanwhile, augmentation and reduction of the relative abundance of pathogenic and probiotic bacteria, respectively, also were observed. Specifically, we found the relative abundance of Actinobacteria increased on a large scale, whereas that of Proteobacteria, Chloroflexi and Acidobacteria decreased dramatically. Moreover, we found that composition changes and quantities of some bacteria (especially Actinomycetes) were closely related to the total phosphorus content of soil. [Conclusion] Excessive application of chemical fertilizers and perennial continuous cropping affected the soil bacterial community and damaged soil ecological environment thus resulting in potato soil-borne diseases eventually. In addition, phosphorus content change may be one of the important factors that alter community structure of soil microbes.
Keywords: high-throughput sequencing    potato    rhizosphere soil    microbial diversity    

马铃薯是我国第四大农作物,播种面积与总产量分别占全世界的30%和40%。近年来,随着国家对马铃薯产业的重视,从事马铃薯生产种植的新型经营主体增加,生产的专业化和规模化程度也越来越高,化肥农药用量不断加大,加之连作等高强度种植模式,导致土壤盐渍化现象普遍发生,土壤生态环境恶化,土传病害逐年加重,给种植者带来巨大的经济损失[1-3]

微生物是土壤的重要组分,在肥力演变、物质循环和促进植物生长发育中发挥着重要作用[4-5],直接影响作物产量和质量。其群落结构的变化可以在一定程度上反映土壤质量的变化趋势[6-7]。高通量测序可1次分析数百万到数千万条的DNA序列[8],已被广泛用于污水、土壤和深海[9-13]等复杂环境的微生物多样性分析,准确掌握群落组分在门、纲、目、科、属和OTU水平上的变化[14-18]

目前,使用高通量测序技术对马铃薯土壤微生物生态结构的研究已有一些报道[19-20],但多集中在不同种植方式、外界环境污染对菌群的影响。而对于土传病害发生与微生物群落结果的相关性研究不多。笔者调查发现河北沽源一块薯田连作3年后黑痣病、疮痂病等土传病害十分严重;宁夏西吉薯田种植1年,田间个别植株发生青枯病;内蒙古呼伦贝尔农垦谢尔塔拉农场马铃薯5年轮作,未发现土传病害。为了探讨这3块薯田土壤生态的差异,我们分别从马铃薯近根际收集土壤,利用高通量测序技术对比了3组样品细菌数量、物种数、多样性、种类丰富度、样本间差异度,从微生物生态角度探寻样品间细菌的群落结构差异,为土传病害的有效防治提供借鉴。

1 材料和方法 1.1 样品采集

采集地点分别为宁夏回族自治区西吉县(东经105.70°,北纬35.97°,10月3日收获)、河北省沽源县常铁炉乡(东经114.89°,北纬41.52°,9月27日收获)和内蒙古自治区呼伦贝尔市海拉尔区(东经119.74°,北纬49.21°,10月11日收获)。其中,西吉年平均气温5 ℃,降水量约410 mm (其中夏秋季降水量约230 mm);沽源年平均气温2.4 ℃,降水量约426 mm (夏秋季降水量约226 mm);海拉尔年平均气温为–2 ℃至–1 ℃,降水量约为351 mm (夏秋季降水量约228 mm)。于各地马铃薯收获前1周采集距离地表 20 cm处的近根际土壤进行分析,9点取样法从每个地块分别获得3组平行样品(编号分别为A1、A2、A3;B1、B2、B3;C1、C2、C3)。

马铃薯收获后统计发病情况。疮痂病害分级标准:0级-薯皮健康,无病斑;1级-病斑面积占块茎总面积的0–1/6;2级-病斑面积占1/6–1/3;3级-病斑面积占1/3–1/2;4级-病斑面积占1/2以上。黑痣病分级标准:0级-薯皮健康;1级-病斑面积占块茎总面积的0–1/20;2级-病斑面积占1/20–1/10;3级-病斑面积占1/10–1/4;4级-病斑面积占1/4–1/2;5级-病斑面积占1/2以上。

发病率(%)=发病块茎数/调查总块茎数×100;病情指数=∑(各病级块茎数×该病级数代表值)/(调查个体总和×最高病级数)×100。

宁夏西吉采样田属黑垆土,马铃薯连作1年,田间个别植株发生青枯病,但未发现疮痂病。河北沽源采样田属耕作型栗钙土,马铃薯3年连作,疮痂病发病率大于30%,病情指数大于13;黑痣病发病率大于50%,病情指数大于13.5。内蒙古海拉尔采样田属草甸土,小麦-甜菜-油菜-小麦-马铃薯5年轮作,田间调查未发现土传病害。

3组样品采集田均为播种前施肥,表 1为具体施肥情况。

表 1. 不同试验大田施肥情况表 Table 1. Fertilization situation in different test fields
Test location Sample No. Name N-P-K Dosage/(t/ha) Manufacturer
Xiji A1、A2、A3 Special fertilizer for potato 15:17:24 0.600 Stanley Dangyang Limited
Carbamide N > 46% 0.075 Ningxia Luxi Chemical Fertilizer Company
(NH4)2PO4 15:42:0 0.075 Yunnan Yuntianhua Company Limited
Guyuan B1、B2、B3 Sakefu compound fertilizer 12:19:16 0.750 China-Arab Chemical Fertilizer Company
KH2PO4 0:52:34 0.225 Guizhou Kai Lin Fertilizer Company
(NH4)2PO4 15:42:0 0.225 Yunnan Yuntianhua Company Limited
Carbamide N > 46% 0.225 Ningxia Luxi Chemical Fertilizer Company
Hailar C1、C2、C3 K2SO4 15:15:15 0.698 China-Arab Chemical Fertilizer Company

1.2 土壤样品总DNA测序

土壤样品委托北京诺禾致源生物信息科技有限公司基于Illumina Miseq技术测序平台构建文库,进行高通量双末端测序。根据相似度,将序列聚类为操作分类单元(OTU),相似度阈值为97%[21]。使用RDP分类器对序列进行系统分类,并在各分类级别上对物种进行统计。凭借OTU数据进行Alpha多样性和Beta多样性分析。

土壤基本理化性质委托北京谱尼测试集团股份有限公司测定,采用容量法检测全氮、水解性氮及有机质含量,紫外可见分光光度法检测全磷、有效磷含量,电感耦合等离子体原子发射光谱法检测全钾、速效钾含量,玻璃电极法检测样品pH值(表 2)。

表 2. 不同地区土壤样品基本理化性质 Table 2. Basic physical and chemical properties of soil samples in different regions
Test location pH SOM/(g/kg) TN/(g/kg) TP/(g/kg) TK/(g/kg) AN/(mg/kg) AP/(mg/kg) AK/(mg/kg)
Xiji 8.2 13.50 0.90 0.77 18.4 54.6 15.3 187
Guyuan 7.2 9.85 0.70 0.32 23.2 47.7 31.6 164
Hailar 7.8 41.8 2.31 0.71 23.1 189.0 54.3 312

2 结果和分析 2.1 OTU聚类及RDP分类

9个样本共计获得617558个原始有效条带。基于97%的序列相似性进行了聚类分析,获得了3077个可分类的操作单元(OTU)。通过RDP分类全部OTUs可划分为32门、46纲、104目、194科、409属。与其他2组样品相比,土传病害严重的河北沽源土壤样品中独有1纲、4目、12科、22属。

2.2 样品细菌群落的α多样性

细菌群落的α多样性结果中物种覆盖率均达到97%以上,表明3组样品所构建的细菌文库能有效地反映其物种多样性,且各组样品多样性指数组内偏差较小,数据可靠。样品B的Shannon指数数值低于A、C 2组,表明其菌落多样性差。从Chao1指数、ACE值和OTU数量结果判断,样品B中细菌数量、物种数均低于A、C 2组样品。且B与A、C 2组样品在Chao1指数和ACE指数上存在显著性差异,B组与C组之间差异达到极显著水平。C组样品的物种丰富度明显最好,其次为A组样品,最差为B组样品(表 3)。

表 3. 不同样品的α多样性指数 Table 3. Alpha diversity index of different samples
Alpha A B C
OTUs 139.333±11.930 148.667±9.539 160.667±10.214
Shannon 8.851±0.109 7.860±0.258 8.915±0.146
Simpson 0.993±0.002 0.975±0.001 0.994±0.001
Chao1 1761.135±153.205 1433.035±148.747 1979.203±171.137
ACE 1767.951±154.973 1438.257±148.228 1998.977±163.566
Coverage 0.991±0.003 0.992±0.001 0.988±0.003

2.3 土壤细菌差异性比较

2.3.1 基于门分类水平(Phylum level)的土壤细菌组分比较:

图 1结果表明,放线菌门Actinobacteria在B组样品中的组分远高于A、C 2组(A 17.3%、B 31.07%、C 15.73%);而变形菌门Proteobacteria (A 1.39%、B 3.71%、C 0.5%)、酸杆菌门Acidobacteria (A 13.53%、B 3.88%、C 6.19%)、芽单胞菌门Gemmatimonadetes (A 1.39%、B 3.71%、C 0.5%)、绿弯菌门Chloroflexi (A 8.30%、B 4.36%、C 6.04%)、硝化螺旋菌门Nitrospirae (A 1.07%、B 0.27%、C 2.37%)和Verrucomicrobia (A 1.77%、B 1.16%、C 1.86%)则表现为相反的结果;B组样品中Proteobacteria (A 33.91%、B 41.88%、C 47.86%)、Bacteroidetes (A 14.07%、B 10.47%、C 8.19%)和unidentified_Bacteria (A 0.41%、B 0.45%、C 1.51%)与A、C 2组无明显区别。

图 1 不同土壤样品间门分类水平菌群分布图(Top 10) Figure 1 Distribution of microflora in different classifications of different soil samples (Top 10).

2.3.2 基于科分类水平(Family level)的土壤细菌组分比较:

图 2所示,样品B中,鞘脂单胞菌科Sphingomonadaceae所占组分最高,其次为伯克氏菌BurkholderiaceaeMicrococcaceaeNocardioidaceaeXanthobacteraceaeGemmatimonadaceaeSphingobacteriaceaeChitinophagaceaeCaulobacteraceae和unidentified_Gammaproteobacteria,且与A、C 2组样品存在明显区别,其中鞘脂单胞菌科Sphingomonadaceae (A 8.53%、B 15.18%、C 4.79%)、伯克氏菌Burkholderiaceae (A 1.88%、B 6.63%、C 1.61%)、Nocardioidaceae (A 2.21%、B 5.67%、C 1.69%)和Sphingobacteriaceae (A 1.39%、B 3.71%、C 0.5%) 4个科所占组分明显增加,而Gemmatimonadaceae (A 7.52%、B 4.26%、C 5.79%)、Chitinophagaceae (A 5.58%、B 2.45%、C 3.55%)、unidentified_Gammaproteobacteria (A 1.47%、B 0.6%、C 4.43%) 3个科所占组分减少。

图 2 不同样品间科分类水平菌群分布图(Top 10) Figure 2 Distribution of microflora in different families among different samples (Top 10).

2.3.3 基于科分类水平(Family level)的土壤细菌数量差异性比较:

B与A、C 2组样品T-Test分析结果显示(图 3),样品B的放线菌纲Gaiellales和弗兰克氏菌科Frankiaceae显著多于A、C 2组样品。而变形菌门的亚硝化单胞菌科NitrosomonadaceaeHaliangiaceae和绿弯菌门的unidentified_Chloroflexi、unidentified_Dehalococcoidia以及酸杆菌门的Pyrinomonadaceae、拟杆菌门的Microscillaceae、芽单胞菌门的Longimicrobiaceae显著少于A、C 2组样品。

图 3 样品间细菌数量差异t-Test比较(科水平) Figure 3 t-Test comparison of differences in the number of bacteria between samples (family level).

2.3.4 基于属分类水平(Genus level)的土壤细菌组分比较:

相对丰度位居前30的细菌组分分析结果显示(图 4):样品B中Sphingomonas (A 5.69%、B 12.97%、C 2.57%)、Pedobacter (A 1.18%、B 3.29%、C 0.37%)、Delftia (A 0.05%、B 1.62%、C 0.06%)、Pelomonas (A 0.02%、B 1.37%、C 0.04%)、Phyllobacterium (A 0.09%、B 1.33%、C 0.27%)、Nocardioides (A 0.75%、B 2.34%、C 0.62%)、Aeromicrobium (A 0.77%、B 1.97%、C 0.62%)、Mycobacterium (A 0.15%、B 1.26%、C 0.55%)、Gemmatimonas (A 0.91%、B 1.85%、C 0.87%)、Massilia (A 0.62%、B 1.74%、C 0.33%)、Kribbella (A 0.56%、B 0.96%、C 0.39%)、Hymenobacter (A 0.27%、B 1.16%、C 0.05%)、Phycicoccus (A 0.25%、B 1.28%、C 0.16%)和Ralstonia (A 0.01%、B 0.06%、C 0.02%)14个属所占组分均高于A、C 2组样品,而Skermanella (A 1.55%、B 0.38%、C 0.78%)、unidentified_Acidobacteria (A 2.33%、B 0.40%、C 0.91%)、Haliangium (A 1.01%、B 0.23%、C 1.74%)、unidentified_Nitrospiraceae (A 0.32%、B 0.10%、C 1.15%)和Bacillus (A 0.51%、B 0.65%、C 1.35%) 5个属表现为相反的结果。

图 4 样品间细菌组分差异属分析(Top 30) Figure 4 Analysis of differences in bacterial components between samples (Top 30).

2.3.5 基于属分类水平(Genus level)的土壤细菌数量差异性比较:

样品B与A、C 2组样品T-Test分析结果显示(图 5):样品B中放线菌门的GaiellaAngustibacterJatrophihabitans以及玫瑰单胞菌(Roseomonas)数量显著多于A、C 2组样品;而变形菌门的HaliangiumPsychroglaciecola,酸杆菌门的土壤酸杆菌unidentified_Acidobacteria,绿弯菌门的unidentified_Chloroflexi、unidentified_Dehalococcoidia数量显著少于A、C 2组样品。

图 5 样品间细菌数量差异t-Test比较(属级水平) Figure 5 t-Test comparison of differences in the number of bacteria between samples (genus level).

2.3.6 样品间UniFrac分析:

unWeighted UniFrac分析结果显示(图 6),A、C未发病2组样品的OTU在进化谱系中更为接近,细菌种类较发病B组样品更相似。

图 6 样品间unWeighted UniFrac分析 Figure 6 UnWeighted UniFrac analysis between samples.

2.4 细菌多样性与环境因子的关系

选择组分位居Top 30且样品间差异明显以及t-Test数量差异显著的细菌,分析其与环境因子的相关性(表 4)发现:16个属与土壤全磷含量存在显著相关性,其中unidentified_Chloroflexi、unidentified_DehalococcoidiaPsychroglaciecola、unidentified_AcidobacteriaHaliangiumSkermanella呈显著正相关,GaiellaAngustibacterJatrophihabitansRoseomonasNocardioidesAeromicrobiumGemmatimonasMassiliaPhycicoccusHymenobacter呈显著负相关;4个属与土壤有机质含量显著相关,其中HaliangiumBacillus和unidentified_Nitrospiraceae呈显著正相关,Roseomonas呈显著负相关;5个属与土壤全氮含量显著相关,HaliangiumBacillus和unidentified_Nitrospiraceae呈显著正相关,RoseomonasMassilia呈显著负相关;unidentified_AcidobacteriaSkermanella 2个属与土壤全钾含量呈显著负相关;4个属与土壤碱解氮含量显著相关,其中HaliangiumBacillus和unidentified_Nitrospiraceae呈显著正相关,Roseomonas呈显著负相关;Bacillus和unidentified_Nitrospiraceae 2个属与土壤有效磷含量呈显著正相关;6个菌属与土壤速效钾含量显著相关,PsychroglaciecolaHaliangiumBacillus和unidentified_Nitrospiraceae呈显著正相关,RoseomonasMassilia呈显著负相关。由此可见,土壤7项指标中,全磷对细菌组分和数量的变化影响最大。值得一提的是,3组样品中与全磷含量呈显著负相关性的10个属中,GaiellaAngustibacterJatrophihabitansNocardioidesAeromicrobiumPhycicoccus均属于放线菌门。

表 4. 细菌多样性与环境因子的关系(属级水平) Table 4. Relationship between bacterial diversity and environmental factors (genus level)
Genus SOM TN TP TK AN AP AK
Gaiella –0.480 –0.488 –0.915** 0.531 –0.432 –0.016 -0.511
Angustibacter –0.310 –0.318 –0.873** 0.639 –0.259 0.154 –0.344
Jatrophihabitans –0.515 –0.522 –0.898** 0.482 –0.469 –0.065 –0.545
Roseomonas –0.725* –0.730* –0.817** 0.208 –0.691* –0.352 –0.746*
unidentified_Chloroflexi 0.357 0.365 0.910** –0.637 0.305 –0.125 0.390
unidentified_Dehalococcoidia 0.618 0.625 0.938** –0.431 0.572 0.159 0.647
Sphingomonas –0.449 –0.452 –0.521 0.144 –0.427 –0.210 –0.462
Delftia –0.287 –0.291 –0.491 0.259 –0.261 –0.041 –0.303
Pelomonas –0.284 –0.288 –0.494 0.264 –0.259 –0.037 –0.301
Phyllobacterium –0.223 –0.227 –0.474 0.298 –0.197 0.022 –0.240
unidentified_Acidobacteria –0.076 –0.068 0.760* –0.868** –0.132 –0.532 –0.040
Haliangium 0.809** 0.812** 0.679* 0.012 0.787* 0.526 0.821**
Nocardioides –0.512 –0.518 –0.836** 0.419 –0.470 –0.098 –0.538
Aeromicrobium –0.452 –0.457 –0.715* 0.346 –0.416 –0.100 –0.474
Skermanella 0.056 0.064 0.745* –0.733* 0.005 –0.370 0.089
Bacillus 0.887** 0.886** 0.344 0.436 0.891** 0.812** 0.882**
Mycobacterium –0.036 –0.042 –0.578 0.576 0.003 0.296 –0.062
Gemmatimonas –0.306 –0.312 –0.669* 0.429 –0.269 0.040 –0.330
Ralstonia –0.281 –0.285 –0.493 0.265 –0.256 –0.034 –0.298
Massilia –0.664 –0.670* –0.861** 0.308 –0.625 –0.257 –0.689*
unidentified_Nitrospiraceae 0.869** 0.870** 0.512 0.243 0.861** 0.693* 0.872**
Phycicoccus –0.566 –0.573 –0.889** 0.426 –0.522 –0.129 –0.594
Kribbella –0.289 –0.291 –0.304 0.060 –0.277 –0.153 –0.296
Hymenobacter –0.642 –0.648 –0.808** 0.273 –0.606 –0.262 –0.665
*: Indicates that the correlation reaches a significant level (P < 0.05); **: Significantly significant correlation level (P < 0.01).

2.5 DRMO和PGPR分析

表 5呈现的是根际土壤中有害病原微生物和非寄生性有害微生物的数量差异(Deleterious rhizosphere microorganisms,简称DRMO)[22-23]。3组样品中主要病原细菌为雷尔氏菌属(RalstoniaRalstonia insidiosa占79.0%)、链霉菌属(Streptomyces)、节细菌属(Arthrobacter)、红球菌属(RhodococcusRhodococcus fascians占33.2%)。其中发病严重的沽源B组样品中雷尔氏菌属、节细菌属、红球菌属的含量较未发病的A、C 2组多。

表 5. DRMO细菌数目表 Table 5. DRMO bacterial count table
Sample Ralstonia Streptomyces Arthrobacter Rhodococcus
A 9 474 11 105
B 753 397 100 851
C 29 497 3 138

表 6列出的是促进植物生长发育或对病原菌具有一定拮抗作用的植物根际有益细菌(Plant growth-promoting rhizobacteria,简称PGPR),主要包括芽孢杆菌属的凝结芽孢杆菌(Bacillus coagulans)占3.1%、简单芽孢杆菌(Bacillus simplex)占80.7%、假单胞菌属的类产碱假单胞菌(Pseudomonas pseudoalcaligenes)占7.3%、温哥华假单胞菌(Pseudomonas vancouverensis)占21.1%、黄杆菌属(Flavobacterium)、慢生根瘤菌属(Bradyrhizobium)、硫杆菌属(Thiobacillus)。其中,海拉尔土壤样品的PGPR细菌数量明显较西吉和沽源样品多。尤其芽孢杆菌属和假单胞菌属的数量显著多于A、B 2组样品。硫杆菌属仅存在于C组样品中。FlavobacteriumBradyrhizobium在样品A中的数量明显少于B、C 2组样品。

表 6. PGPR细菌数目表 Table 6. PGPR bacterial count table
Sample Bacillus Pseudomonas Flavobacterium Azotobacter Bradyrhizobium Thiobacillus
A 644 831 668 0 376 0
B 651 500 1329 10 1630 0
C 1861 2363 1494 1 1709 44

除此之外,在C组样品中存在大量的Rhodanobacter lindaniclasticusTerrimonas。有文献报道前者能有效降解有机农药和持久性有机污染物[24],后者仅存在于有机质丰富的环境中[25]。上述数据间接反映了C组样品的土壤环境更优。

综上所述,河北沽源采样田的施肥量是宁夏西吉和内蒙古海拉尔采样地的2倍左右,且多年连作,导致其细菌数量、多样性、种类丰富度均明显降低,放线菌数量增多,变形菌、绿弯菌、酸杆菌明显减少,根际益生菌数量减少,病原细菌(及潜在的)数量明显增多。宁夏西吉采样田1年连作,虽然病原细菌(及潜在的)数量并未明显增多,但其根际益生菌的数量最少。此外,研究中发现全磷含量与细菌群落结构变化的关系最为密切。

3 讨论

宁夏西吉、内蒙古海拉尔和河北沽源3块采样田同属于北方产区,均为集约化垄作双行种植和农机作业,夏秋季降雨量相近,但土传病害发病程度却截然不同。我们调查发现,三者主要区别在于种植方式和施肥量。其中,沽源采样田的大肥连作生产方式是华北地区马铃薯集约化生产的典型代表,疮痂病高发难防,已经严重影响到当地产业的可持续发展;呼伦贝尔农垦土地资源丰富,坚持轮作倒茬,施肥量小,很少发生疮痂病;宁夏西吉种植1年的薯田,施肥量较小,除发现少量的青枯病植株外未见疮痂病薯。有报道称,土传病害的危害程度跟种植方式密切相关[26]。为此,本文以上述3个薯田土样作为研究对象,综合分析了细菌群落与种植方式等因素之间的相互关系。虽然采集田相距较远,其土壤性质和质地的差异无疑会影响样品基本细菌类群组成,对结果分析产生一定影响,但在同一采样田分别选取和测定了3个平行样品,重复间数据差异小、可靠性强;且与疮痂病高发土样相比,未发病两组样品的细菌种类更为相似。可见,本文分析结果具有一定的代表性,能通过其细菌菌群结构折射出薯田种植方式与疮痂病危害的相关性,可为生产实践提供借鉴。

利用高通量测序技术能够准确测出大多数微生物的16S rDNA序列,已被越来越多地应用于研究植物和土壤环境中微生物的群落结构和多样性。马铃薯疮痂病属于细菌性土传病害,目前尚无防效十分显著的化学药剂及其他措施,但已有一些文章研究报道了细菌对其产生的拮抗作用[27]。近年来我们从全国各主要产区的发病大田中分离和鉴定出80余株对疮痂链霉菌具有拮抗效果的细菌,并以此为基础开发出复合功能菌剂进行试验和示范,获得了良好的防控效果,关于真菌对放线链霉菌的拮抗效果报道较少。因此,本文将关注点集中在细菌种群结构变化与疮痂病发生的相关性分析。通过对宁夏西吉、河北沽源和内蒙古海拉尔3个生态区大田马铃薯根际土壤进行高通量测序分析表明,马铃薯疮痂病高发的土壤样品中放线菌数量及所占比例增多而变形菌、绿弯菌、酸杆菌等减少是一明显特征,这一结果与崔丙健等[28]、杨尚东等[29]的结果相似。变形菌门的一些菌种已被广泛应用于植物病虫害防治、肥料高效利用、工业废水处理和复杂污染物降解等[30]。其中δ-变形菌纲Deltaproteobacteria对土壤中的有机质、氮、磷、硫的循环都有显著的促进作用[31]。绿弯菌门的细菌可通过光合作用产生能量,在理化性质优良的土壤中相对丰富度可达10% [32]。酸杆菌Acidobacteria是新划分出的一门细菌,在土壤细菌中占比很高,一般嗜酸、寡营养、难培养[33]

分析科分类水平差异显著性位于Top10的细菌发现,土传病害严重的土样中鞘脂单胞菌科Sphingomonadaceae和伯克氏菌科Burkholderiaceae细菌所占组分变化最为明显,尤其是前者。研究显示,鞘脂单胞菌科细菌可用于芳香族化合物的生物降解,是一种新型的应用微生物资源,在富营养化的环境中组比升高[34],这可能与河北沽源样品采集田过量施肥有关。伯克氏菌科中大部分为动植物病原菌,导致多种植物发生青枯病的青枯雷尔氏菌也属这个科。

DRMO分析数据表明,在土传病害严重发生的样品中,病原菌(及潜在的)数量明显增多。其中青枯雷尔氏菌属(Ralstonia insidiosa)是一种典型的细菌性病害,寄生范围广,可通过伤口或根尖进入根部,入侵植物木质部导管,致使多种重要经济作物感病,并阻碍植物水分运输[35];红球菌属细菌(Rhodococcus fascians),是香豌豆带化病(Sweetpea fasciansdowson)的致病菌[36]。节细菌属的某些菌株具有一定的解磷能力,但大多具有致病性,代表种Arthrobacter ilicis可致叶片疫病[37]。我们曾于2017年从河北沽源疮痂病高发田(B组样品采集地)的病薯中分离到了欧洲疮痂链霉菌,但测序结果中未显示出,推测可能与数据库的数据完善程度有关。

另外,在疮痂病严重发生的样品中PGPR细菌数量显著降低。其中芽孢杆菌是重要的农业微生物资源,在土壤、动物肠道、空气、水以及植物体内普遍存在,可溶解难溶磷、钾等化合物,能有效拮抗镰刀菌(Fusarium)、曲霉菌(Aspergillus)、丝核菌(Rhizoctonia)、疮痂链霉菌(Streptomyces scabies)等多种病原菌[38];简单芽孢杆菌能够快速分解有机物、降氨氮,且对马铃薯疮痂病有一定的拮抗效果[39];凝结芽孢杆菌仅存在于C组样品中,是良好的抗腐剂,且与植物抗病密切相关[40]。假单胞菌属的类产碱假单胞菌是昆虫致病菌,能够杀死草地蝗虫和竹蝗等[41];温哥华假单胞菌具有一定的解磷能力,可将土壤中难以吸收的磷分解成为有效磷,从而促进核桃生长[42]。黄杆菌(Flavobacterium)具有较好的解磷能力[43];根瘤菌是最常见的PGPR细菌,除与植物共生、增加固氮能力外,部分根瘤菌也有解磷作用[44]。硫杆菌属也仅存在于C组样品中,这一类菌大多具有解磷作用[45]

土传病害发生严重的沽源土样中细菌数量和物种丰富度均有所降低,有害菌数量增加,益生菌数量减少,且样品间组分和数量差异显著的细菌(尤其是放线菌门)大多与土壤全磷含量相关,推测磷可能是肥料中影响土壤微生物群落结构变化最主要的元素。肥料三要素中的氮在土壤中容易流失,马铃薯生长发育过程中对钾肥需求量最大,绝大部分被吸收和利用,而磷肥则相对稳定地存在于土壤中,对薯田生态环境的影响可能更为显著,其具体作用机理有待进一步深入探索。纪梦梦等[46]报道长期施用化肥和长期单一施用化肥均会大幅降低微生物多样性,提高根际放线菌数量;而单施有机肥可增加绿弯菌、拟杆菌数量[47];作物长期连作会导致根系分泌物积累,改变土壤微生物类群,抑制有益微生物生长,降低土壤微生物多样性,土壤理化性质和生化性质下降,最终使病原菌积累、植株感病[48]。在高强度种植过程中,轮作倒茬能充分利用土壤养分,改善土壤理化性质,减少病原菌积累,为益生菌的生长提供更良好的条件[49-50]。熊兴耀等[51]研究发现连作马铃薯根际土壤中,非有益细菌显著增多;影响土壤细菌群落结构的重要土壤理化因子包括速效磷、速效钾、总有机碳含量以及pH,其中pH和总有机碳含量最为关键,这与我们的研究结果不同,可能与取样地肥料施用情况有关。

综上,过量施用化肥和常年连作导致土壤生态环境和理化性质恶化,不利于大多数细菌的生长,一些与病原菌存在拮抗关系的细菌生长会受到一定程度的影响,势必导致少数病原菌的积累和病害暴发。因此,轮作倒茬、合理施肥,尤其降低磷肥用量,可改善土壤微生物群落结构,减少疮痂等土传病害发生,利于马铃薯产业可持续发展。

References
[1] Tu Y, Yang WY, Liu WG, Yong TW, Jiang LQ, Wang XC. Effects of different intercropping years of soybean and flue-cured tobacco on the rhizosphere soil microbe. Acta Agronomica Sinica, 2015, 41(5): 733-742. (in Chinese)
涂勇, 杨文钰, 刘卫国, 雍太文, 江连强, 王小春. 大豆与烤烟不同套作年限对根际土壤微生物数量的影响. 作物学报, 2015, 41(5): 733-742.
[2] Zhong NQ, Li D, Ren YY, Liu N, Zhao P. Precise poverty alleviation aided by modern agriculture technology-Practice and inspiration from IMCAS's actions on promoting potato industry in poverty regions. Bulletin of the Chinese Academy of Sciences, 2019, 34(3): 349-356, 244. (in Chinese)
仲乃琴, 李丹, 任园园, 刘宁, 赵盼. 现代农业科技助力马铃薯产业精准扶贫——中国科学院微生物研究所马铃薯产业科技扶贫实践与启示. 中国科学院院刊, 2019, 34(3): 349-356, 244.
[3] Zhong NQ, Liu N, Zhao P, Cai DQ, Song SW, Chao YP. Current status and challenges for potato chemical fertilizer & pesticide reductions in China. Chinese Science Bulletin, 2018, 63(17): 1693-1702. (in Chinese)
仲乃琴, 刘宁, 赵盼, 蔡冬清, 宋双伟, 钞亚鹏. 中国马铃薯化肥农药减施的现状与挑战. 科学通报, 2018, 63(17): 1693-1702.
[4] Larkin RP. Characterization of soil microbial communities under different potato cropping systems by microbial population dynamics, substrate utilization, and fatty acid profiles. Soil Biology and Biochemistry, 2003, 35(11): 1451-1466. DOI:10.1016/S0038-0717(03)00240-2
[5] Qin Y, Ma K, Liu P. Effect of potato continuous cropping on genetic diversity of soil microorganisms. Chinese Journal of Eco-Agriculture, 2015, 23(2): 225-232. (in Chinese)
秦越, 马琨, 刘萍. 马铃薯连作栽培对土壤微生物多样性的影响. 中国生态农业学报, 2015, 23(2): 225-232.
[6] 许光辉, 李振高. 微生物生态学. 南京: 东南大学出版社, 1991: 127-128.
[7] Li Z, Yuan Y, Ma L, Tang QM, Zou L. Effects of different rotations on the amount and distribution of soil microorganisms in Mudanjiang tobacco-cropping areas. Journal of Northeast Forestry University, 2010, 38(7): 96-99. (in Chinese)
李喆, 元野, 马力, 唐庆明, 邹莉. 不同轮作方式对牡丹江地区烟田土壤微生物数量及分布的影响. 东北林业大学学报, 2010, 38(7): 96-99.
[8] Schuster SC. Next-generation sequencing transforms today's biology. Nature Methods, 2008, 5(1): 16-18. DOI:10.1038/nmeth1156
[9] Qin N, Li DF, Yang RJ. Next-generation sequencing technologies and the application in microbiology-a review. Acta Microbiologica Sinica, 2011, 51(4): 445-457. (in Chinese)
秦楠, 栗东芳, 杨瑞截. 高通量测序技术及其在微生物学研究中的应用. 微生物学报, 2011, 51(4): 445-457.
[10] Modahl CM, Durban J, Mackessy SP. Exploring toxin evolution: Venom protein transcript sequencing and transcriptome-guided high-throughput proteomics//Priel A. Snake and Spider Toxins. Methods in Molecular Biology. New York: Humana, 2020, 2068: 97-127.
[11] Adamopoulos PG, Tsiakanikas P, Kontos CK, Panagiotou A, Vassilacopoulou D, Scorilas A. Identification of novel alternative splice variants of the human L-DOPA decarboxylase (DDC) gene in human cancer cells, using high-throughput sequencing approaches. Gene, 2019, 719: 144075. DOI:10.1016/j.gene.2019.144075
[12] Xia WW, Jia ZJ. Comparative analysis of soil microbial communities by pyrosequencing and DGGE. Acta Microbiologica Sinica, 2014, 54(12): 1489-1499. (in Chinese)
夏围围, 贾仲君. 高通量测序和DGGE分析土壤微生物群落的技术评价. 微生物学报, 2014, 54(12): 1489-1499.
[13] Lou J, Liu Y, Li Y. Review of high-throughput sequencing techniques in studies of soil microbial diversity. Chinese Agricultural Science Bulletin, 2014, 30(15): 256-260. (in Chinese)
楼骏, 柳勇, 李延. 高通量测序技术在土壤微生物多样性研究中的研究进展. 中国农学通报, 2014, 30(15): 256-260.
[14] Li XZ, Rui JP, Mao YJ, Yannarell A, Mackie R. Dynamics of the bacterial community structure in the rhizosphere of a maize cultivar. Soil Biology and Biochemistry, 2014, 68: 392-401. DOI:10.1016/j.soilbio.2013.10.017
[15] Chen DM, Duan YQ, Yang YH, Jin Y, Huang JG, Yuan L. Effects of long-term fertilization on flue-cured tobacco soil nutrients and microorganisms community structure. Scientia Agricultura Sinica, 2014, 47(17): 3424-3433. (in Chinese)
陈丹梅, 段玉琪, 杨宇虹, 晋艳, 黄建国, 袁玲. 长期施肥对植烟土壤养分及微生物群落结构的影响. 中国农业科学, 2014, 47(17): 3424-3433.
[16] Clegg CD, Ritz K, Griffiths BS. Direct extraction of microbial community DNA from humified upland soils. Letters in Applied Microbiology, 1997, 25(1): 30-33. DOI:10.1046/j.1472-765X.1997.00166.x
[17] Grodetskii YA, Dukarevich YE, Ivanov YM, Sinitsyn AS. A new generation of precision absolute angle-data transmitters. Measurement Techniques, 2012, 55(9): 1005-1011. DOI:10.1007/s11018-012-0090-0
[18] Chen Y, Wu C, Li CB, Lin YC, Cheng JZ, Pan WJ. Effect of biochar-based fertilizer on bacterial and fungal community composition, diversity in tobacco-planting yellow soil. Acta Microbiologica Sinica, 60(4): 653-666. (in Chinese)
陈懿, 吴春, 李彩斌, 林叶春, 程建中, 潘文杰. 炭基肥对植烟黄壤细菌、真菌群落结构和多样性的影响. 微生物学报, 60(4): 653-666. DOI:10.13343/j.cnki.wsxb.20190258
[19] Tan XL, Guo XD, Ma MS, Liu GY, Zhang PL, Lv JF, Guo TW. Effects of continuous cropping on soil microflora and yield of potato. Acta Agriculturae Nucleatae Sinica, 2012, 26(9): 1322-1325, 1321. (in Chinese)
谭雪莲, 郭晓冬, 马明生, 刘高远, 张平良, 吕军峰, 郭天文. 连作对马铃薯土壤微生物区系和产量的影响. 核农学报, 2012, 26(9): 1322-1325, 1321.
[20] Zhang GQ, Zhao P, Dong YX, Wu DB, Zheng WP, Zhan H, Chao YP, Zhong NQ. Effects of a novel fertilizer synergist on fungi diversity from potato rhizosphere soil. Microbiology China, 2017, 44(11): 2644-2651. (in Chinese)
张国青, 赵盼, 董彦旭, 武东波, 郑维平, 詹虹, 钞亚鹏, 仲乃琴. 高通量测序分析环保肥料增效剂对马铃薯根际土壤真菌多样性变化影响. 微生物学通报, 2017, 44(11): 2644-2651.
[21] Jin L, Zhou ML, Wang LL, Liu KZ, Wang LZ. Differences of microbial structure and composition in goat rumens with different energy metabolism efficiency. Microbiology China, 2018, 45(1): 91-101. (in Chinese)
金磊, 周美丽, 王禄禄, 刘凯珍, 王立志. 不同能量代谢率的山羊瘤胃微生物结构与组成的差异性. 微生物学通报, 2018, 45(1): 91-101.
[22] Jaroszuk-Ściseł J, Kurek E. Hydrolysis of fungal and plant cell walls by enzymatic complexes from cultures of Fusarium isolates with different aggressiveness to rye (Secale cereale). Archives of Microbiology, 2012, 194(8): 653-665. DOI:10.1007/s00203-012-0803-4
[23] Feng J. Recent advances in taxonomy of plant pathogenic bacteria. Scientia Agricultura Sinica, 2017, 50(12): 2305-2314. (in Chinese)
冯洁. 植物病原细菌分类最新进展. 中国农业科学, 2017, 50(12): 2305-2314.
[24] Zhang HY, Li M, Qiu XH. Advances in biodegradation of organochlorine insecticide, γ-HCH. Microbiology China, 2007, 34(5): 965-969. (in Chinese)
张海燕, 李梅, 邱星辉. 持久性有机污染物γ-六六六生物降解研究进展. 微生物学通报, 2007, 34(5): 965-969.
[25] Yuan RQ, Niu YD, Wang P, Wang SQ. Effects of the Yellow River diversion on microbial communities in sediments of the receiving reach. Acta Scientiae Circumstantiae, 2019, 39(2): 499-508. (in Chinese)
袁瑞强, 牛漾聃, 王鹏, 王仕琴. 引黄对受水河段沉积物微生物群落的影响. 环境科学学报, 2019, 39(2): 499-508.
[26] Chen LH, Chang YJ, Wang CC, Shao XH, Ma CY, Xu MX, Wang DS. Population, toxicity and pathogenicity of Fusarium oxysporum in continuously cropped soil of Artemisia selengens with or without Fusarium wilt. Chinese Journal of Applied and Environmental Biology, 2015, 21(2): 228-233. (in Chinese)
陈立华, 常义军, 王长春, 邵孝侯, 马超越, 徐明喜, 王东升. 发生和未发生连作芦蒿枯萎病土壤的尖孢镰刀菌数量、产毒能力和致病力. 应用与环境生物学报, 2015, 21(2): 228-233.
[27] Cui X, Xu YX, Liu JJ, Guo ZK, Wang GH. Advances of Bacillus application in agriculture:A review. Soil and Crops, 2019, 8(1): 32-42. (in Chinese)
崔晓, 徐艳霞, 刘俊杰, 郭兆奎, 王光华. 芽孢杆菌在农业生产中的应用. 土壤与作物, 2019, 8(1): 32-42.
[28] Cui BJ, Gao F, Hu C, Li ZY, Fan XY, Cui EP. Effects of different reclaimed water irrigation methods on bacterial community diversity and pathogen abundance in soil-capsicum system. Environmental Science, 2019, 40(11): 5151-5163. (in Chinese)
崔丙健, 高峰, 胡超, 李中阳, 樊向阳, 崔二苹. 不同再生水灌溉方式对土壤-辣椒系统中细菌群落多样性及病原菌丰度的影响. 环境科学, 2019, 40(11): 5151-5163.
[29] Yang SD, Guo S, Ren KY, Pang SC, Zhang CJ, Wang SS, Tan HW. Soil biological properties and bacterial community structures in rhizosphere soil of canes infected and non-infected by ratoon stunting disease. Journal of Plant Nutrition and Fertilizers, 2019, 25(6): 910-916. (in Chinese)
杨尚东, 郭霜, 任奎喻, 庞师婵, 张传进, 王帅帅, 谭宏伟. 甘蔗宿根矮化病感病与非感病株根际土壤生物学性状及细菌群落结构特征. 植物营养与肥料学报, 2019, 25(6): 910-916.
[30] Pu SY, Zhang XL, Jiang TJ, Gao BD. Metagenomics research and its applications in virus detection. Acta Biophysica Sinica, 2014, 30(1): 3-14. (in Chinese)
浦绍艳, 张鑫磊, 蒋太交, 高必达. 宏基因组学研究方法及其在病原体检测中的应用. 生物物理学报, 2014, 30(1): 3-14.
[31] Ge YL, Liu ZL, Chen L, Luo L. Screening and identification of marine actinomycetes for biocontrol on Rhizoctonia cerealis. Agrochemicals, 2018, 57(2): 111-113, 136. (in Chinese)
葛玉力, 刘兆良, 陈玲, 罗兰. 小麦纹枯病生防海洋放线菌的筛选与鉴定. 农药, 2018, 57(2): 111-113, 136.
[32] Zhang S, Zhang YJ, Zhao Y, Zhang YH, Hu Q, Jing YL, Fu J. Effects of rice straw biochar prepared at different pyrolysis temperatures on carbon sequestration and mitigation and microbial community structure in paddy soil. Jiangsu Journal of Agricultural Sciences, 2019, 35(5): 1102-1111. (in Chinese)
张晟, 张徐洁, 赵远, 张玉虎, 胡茜, 荆玉林, 符菁. 不同温度制备的水稻秸秆生物炭对稻田土壤固碳减排及微生物群落结构的影响. 江苏农业学报, 2019, 35(5): 1102-1111.
[33] Wang GH, Liu JJ, Yu ZH, Wang XZ, Jin J, Liu XB. Research progress of acidobacteria ecology in soils. Biotechnology Bulletin, 2016, 32(2): 14-20. (in Chinese)
王光华, 刘俊杰, 于镇华, 王新珍, 金剑, 刘晓冰. 土壤酸杆菌门细菌生态学研究进展. 生物技术通报, 2016, 32(2): 14-20.
[34] Ding SL, Xue S, Liu GB. Effects of fertilization on soil enzyme activities and water-soluble organic carbon and nitrogen content in farmland on Hilly Loess Plateau. Journal of Agro-Environment Science, 2015, 34(11): 2146-2154. (in Chinese)
丁少男, 薛萐, 刘国彬. 施肥处理对黄土丘陵区农田土壤酶活性和水溶性有机碳、氮的影响. 农业环境科学学报, 2015, 34(11): 2146-2154.
[35] Salanoubat M, Genin S, Artiguenave F, Gouzy J, Mangenot S, Arlat M, Billault A, Brottier P, Camus JC, Cattolico L, Chandler M, Choisne N, Claudel-Renard C, Cunnac S, Demange N, Gaspin C, Lavie M, Moisan A, Robert C, Saurin W, Schiex T, Siguier P, Thébault P, Whalen M, Wincker P, Levy M, Weissenbach J, Boucher CA. Genome sequence of the plant pathogen Ralstonia solanacearum. Nature, 2002, 415(6871): 497-502. DOI:10.1038/415497a
[36] Qiu ZB, Wang R, Zhang Y, Wu Q, Xie BJ, Yang JF, Chen JG, Sun ZD. Recent progress in studies of Rhodococcus and its application of in biodegradation. Food Science, 2016, 37(7): 254-258. (in Chinese)
邱孜博, 汪荣, 张杨, 吴茜, 谢笔钧, 杨季芳, 陈吉刚, 孙智达. 红球菌及其生物降解作用研究进展. 食品科学, 2016, 37(7): 254-258.
[37] Zhen YG, Chen X, Pu GH, Zhao W, Qin GX, Wang T, Wang XL, Zhang XF. Effects of the combination of Aspergillus oryzae culture and yeast culture on the diversity of rumen flora in sheep. Chinese Journal of Animal Science, 2018, 54(6): 96-100. (in Chinese)
甄玉国, 陈雪, 朴光赫, 赵巍, 秦贵信, 王涛, 王晓磊, 张学峰. 米曲霉培养物与酵母培养物组合对绵羊瘤胃菌群多样性的影响. 中国畜牧杂志, 2018, 54(6): 96-100.
[38] Yang DQ, Zhou CF, Huang LW, Zhang XX, Wang LF, Liu J, Zhang WJ, Lian PK. Research progress of endophytic Bacillus on plant growth and disease control. Journal of Anhui Agricultural Sciences, 2020, 48(4): 11-14. (in Chinese)
杨得强, 周春发, 黄龙伟, 张晓旭, 王龙飞, 刘佳, 张文静, 连培康. 内生芽孢杆菌对植物生长发育及病害防治的研究进展. 安徽农业科学, 2020, 48(4): 11-14.
[39] Yang WP, Ding YQ, Ma MK, Xiao LL, Chen WG, Zhang YW. Isolation and identification of cellulolytic bacteria from animal feces. Acta Ecologae Animalis Domastici, 2019, 40(2): 75-79, 85. (in Chinese)
杨伟平, 丁雅倩, 马梦柯, 肖琅琅, 陈万光, 张耀文. 动物粪便中纤维素分解菌的分离和鉴定. 家畜生态学报, 2019, 40(2): 75-79, 85.
[40] Yan T, Zhu JG, Jiang T, Chen KK, Fang SG. Isolation and optimization on spore-forming conditions of Bacillus coagulans. Microbiology China, 2018, 45(2): 238-249. (in Chinese)
严涛, 朱建国, 姜甜, 陈珂可, 方曙光. 一株凝结芽孢杆菌的分离筛选及产孢条件优化. 微生物学通报, 2018, 45(2): 238-249.
[41] Yi HX, Zhang J, Hou RT, Wang JD, Yang ZR. Isolation and identification of a chitinase-producing bacterium and its synergistic effect on locust biocontrol. Plant Protection, 2004, 30(2): 37-41. (in Chinese)
尹鸿翔, 张杰, 侯若彤, 王建东, 杨志荣. 一株几丁质酶产生菌的分离鉴定及其灭蝗增效作用. 植物保护, 2004, 30(2): 37-41.
[42] Qiao TM, Li SJ, Han S, Zhu TH, Wang SS. The phosphate-solubilizing ability and growth promoting effects of Pseudomonas vancouverensis strain PAN4 on walnut. Journal of South China Agricultural University, 2015, 36(5): 117-124. (in Chinese)
谯天敏, 李姝江, 韩珊, 朱天辉, 王树山. 温哥华假单胞菌菌株PAN4解磷能力及对核桃的促生作用. 华南农业大学学报, 2015, 36(5): 117-124.
[43] Zhang DZ, Wen JY, Zhou WC, Wu XY. Hospital infection and multidrug resistance of Flavobacterium:characteristics and analysis. Chinese Journal of Nosocomiology, 2009, 19(15): 2040-2043. (in Chinese)
张德忠, 温建艳, 周文聪, 吴晓燕. 黄杆菌属医院感染特性与多药耐药分析. 中华医院感染学杂志, 2009, 19(15): 2040-2043.
[44] Gao P, Li F, Guo YE, Duan TY. Advances in AM fungi and rhizobium to control plant fungal diseases. Acta Agrestia Sinica, 2017, 25(2): 236-242. (in Chinese)
高萍, 李芳, 郭艳娥, 段廷玉. 丛枝菌根真菌和根瘤菌防控植物真菌病害的研究进展. 草地学报, 2017, 25(2): 236-242.
[45] Zhang WJ, Cui YB, Wang Y, Chen ZL, Li YQ. On the endophytic bacteria diversity of the reed in the sludge drying reed bed. Journal of Safety and Environment, 2017, 17(4): 1407-1412. (in Chinese)
张万筠, 崔玉波, 王毅, 陈兆亮, 李亚琪. 污泥干化芦苇床中芦苇内生菌群多样性研究. 安全与环境学报, 2017, 17(4): 1407-1412.
[46] Ji MM, Wu XG, Wu XX, Wu QY, Li J, Qin XC, Zhang XJ. Effect of overuse nitrogen fertilizer on bacterial community and N2O emission from greenhouse soil. Microbiology China, 2018, 45(6): 1323-1332. (in Chinese)
纪梦梦, 吴晓刚, 吴欣欣, 吴巧玉, 李冀, 秦先超, 张晓君. 过量施肥对设施菜田土壤菌群结构及N2O产生的影响. 微生物学通报, 2018, 45(6): 1323-1332.
[47] 艾超.长期施肥下根际碳氮转化与微生物多样性研究.中国农业科学院博士学位论文, 2015.
[48] Shi M, Li JY, Zhou Q, Wang GB, Zhang WG, Zhang ZH, Gao Y, Yan SH. Interactions between elevated CO2 levels and floating aquatic plants on the alteration of bacterial function in carbon assimilation and decomposition in eutrophic waters. Water Research, 2020, 171: 115398. DOI:10.1016/j.watres.2019.115398
[49] Bennett AJ, Bengding GD, Chendler D, Hidoa A, Mills P. Meeting the demand for crop production:the challenge of yield decline in crops grown in rotations. Biological Reviews, 2012, 87(1): 52-71. DOI:10.1111/j.1469-185X.2011.00184.x
[50] Acosta-Martdaz V, Burow G, Zobeck TM, Allan VG. Soil microbial communities and function in alternative systems to continuous cotton. Soil Science Society of America Journal, 2010, 74(4): 1181-1192. DOI:10.2136/sssaj2008.0065
[51] Hu QL, Tan L, Tang XX, Deng Y, Gu SS, Chen JR, Cai L, Zhou Q, Hu XX, Qian YZ, Xiong XY. The divergence of bacterial communities among continuous cropping, rotational cropping and new planting potato soils. International Journal of Agriculture and Biology, 2020, 23: 721-729.