生姜样地根际土壤AM真菌群落结构分析

Arbuscular Mycorrhizal Fungi Community Structure of Ginger Rhizosphere Soils

【目的】分析健康生姜(Zingiber officinale Rosc.)和患病生姜样地根际土壤丛枝菌根(Arbuscular mycorrhiza,AM)真菌群落组成,为利用微生态调控手段进行姜瘟病综合防治提供理论依据。【方法】采集广西桂林、柳州和百色三地姜田的健康和患病生姜根际土壤样品10个(健康生姜土壤样品为KJJ2_S、BMJ1_S、LCJ1_S、FGJ_S和NGJ_S,患病生姜土壤样品为KJB2_S、BMB1_S、LCB1_S、FGB_S和NGB_S),采用Illumina MiSeq高通量测序技术,分析其AM真菌的多样性及群落结构,结合冗余分析(RDA)明确AM真菌群落结构与土壤养分含量的相关性。【结果】在97%相似度水平下,所有患病生姜土壤样品的操作分类单元(OTU)数和Chao 1指数均高于健康生姜土壤样品;健康生姜土壤样品的Shannon指数和Simpson指数均高于患病生姜土壤样品,即健康生姜土壤样品AM真菌的物种多样性指数均高于患病生姜土壤样品。在群落组成方面,在属分类水平上,312个OTUs被分为类球囊霉属(Paraglomus)、无梗囊霉属(Acaulospora)、球囊霉属(Glomus)、球囊霉纲未分类属(unclassified_c_Glomeromycetes)和其他类别。冗余分析结果表明,土壤速效P含量对AM真菌群落组成具有显著影响(P<0.05,下同),全N、有机质、Mg含量和pH对AM真菌群落组成的影响不显著(P>0.05);Heatmap图分析结果表明,Paraglomus与有效P含量呈极显著负相关(P<0.01),与有机质含量呈显著负相关。【结论】健康生姜样地和患病生姜样地土壤的AM真菌群落组成存在明显差异,患姜瘟病生姜根际土壤AM真菌的OTUs数和丰度均高于健康生姜根际土壤,但其多样性低于健康生姜根际土壤;不同采样点生姜根际土壤AM真菌的优势种属存在差异,其多样性、丰度及群落组成结构主要受有效P含量影响。

【Objective】The present paper aimed to analyze the composition of arbuscular mycorrhiza(AM)fungi in the rhizosphere soil of healthy and diseased ginger plots to provide a theoretical basis for the comprehensive control of ginger blast using micro-ecological control methods.【Method】Using ginger fields with different disease severities in Guilin,Liuzhou and Baise,ten soil samples were collected from the following fields:Guilin Quanzhou,Liuzhou Sandu,Liuzhou Liucheng,Baise Debao and Baise Tianlin.Healthy and diseased ginger numbers are KJJ2_S,BMJ1_S,LCJ1_S,FGJ_S,NGJ_S,KJB2_S,BMB1_S,LCB1_S,FGB_S and NGB_S.Illumina Miseq high-throughput sequencing technique was used to study the diversity and community structure of AM fungi in the soil.The correlation between fungal community structure and soil nutrients was clarified with redundancy analysis(RDA).【Result】At the similarity level of 97%,the OTU number and Chao index of fungi in diseased samples were higher than those of healthy samples.By evaluating the diversity index of the AM fungi species through the Shannon index and Simpson index,it was found that the healthy samples had a higher diversity index compared to the diseased samples in all the sample fields.In terms of community composition at the genus level,312 OTUs are classified into Paraglomus,Acaulospora,and Glomus and unclassified_c_Glomeromycetes.RDA results showed that soil available phosphorus significantly affected the AM fungal community(P<0.05,the same as below),and total nitrogen,organic matter,pH,and Magnesium(Mg)had no significant effects on the AM fungal community(P>0.05).The results of Heatmap analysis showed that Paraglomus was significantly negatively correlated with available phosphorus content(P<0.01),and significantly negatively correlated with organic matter content.【Conclusion】There are differences in the composition of AM fungal community between ginger healthy plots and diseased plots.The OTUs number and abundance of AM fungi of diseased ginger soil are higher than healthy ginger soil,but less diversity than healthy ginger soil.Dominant species of AM fungi at different sampling points are different,and their diversity,abundance and community composition structure are mainly affected by effective P content.