玉米根际土壤微生物群落结构及多样性季节变化特征

Seasonal Variation Characteristics of Soil Microbial Community Structure and Diversity of Corn in Rhizosphere Soil

【目的】研究玉米根际与非根际土壤微生物群落结构及多样性季节变化特征。【方法】利用Illumina-MiSeq高通量测序技术对不同季节玉米根际与非根际土壤中细菌的16S rDNA基因V3~V4区片段和真菌18S rDNA基因V4区片段进行了测序。【结果】①不同季节玉米根际与非根际土壤理化性质随季节变化趋势一致,玉米根际、非根际土壤电导率随季节呈先增加后降低趋势,大致表现为夏季>秋季>春季>冬季,不同季节玉米根际土壤电导率均显著高于非根际(P<0.05);由春季到冬季,玉米根际、非根际pH值呈先降低后增加趋势,大致表现为春季>冬季>秋季>夏季,不同季节玉米根际土壤电导率均显著低于非根际(P<0.05)。②不同季节玉米根际与非根际土壤养分含量(有机碳、全氮和全钾)随季节变化趋势相一致,由春季到冬季,玉米根际、非根际养分含量均呈先增加后降低趋势,以夏季玉米根际、非根际土壤养分含量最高,冬季玉米根际、非根际土壤养分含量最低,并有所波动。③不同季节玉米根际与非根际土壤细菌和真菌覆盖度、丰富度指数、Shannon-Wiener指数、均匀度Evenness、ACE、Chao 1指数、Simpson指数随季节变化趋势相一致,由春季到冬季,根际、非根际土壤细菌和真菌多样性指数均呈先增加后降低趋势,并且不同季节根际土壤细菌和真菌多样性指数均显著高于非根际。④玉米根际和非根际土壤细菌群落中,优势类群主要是变形菌门、酸杆菌门和芽单胞菌门,还包括浮霉菌门、放线菌门、拟杆菌门、后壁菌门、绿弯菌门、疣微菌门,其中根际土壤细菌酸杆菌门相对丰度高于非根际,变形菌门相对丰度低于非根际。根际和非根际土壤真菌群落中,优势类群主要是子囊菌门和担子菌门,还包括结合菌门、壶菌门、新丽鞭毛菌门、球囊菌门、芽枝菌门。⑤相关性分析表明:玉米土壤细菌和真菌Coverage、ACE与土壤养分均没有显著的相关性(P>0.05);土壤pH与土壤细菌和真菌多样性呈负相关,土壤电导率和全磷与土壤细菌和真菌多样性均没有显著的相关性(P>0.05)。【结论】玉米土壤根际和非根际细菌和真菌群落具有很好的相似性,并且根际和非根际细菌群落产生明显的分离效应。

【Objective】The present paper aimed to explore seasonal variation characteristics of soil microbial community structure and diversity of corn in rhizosphere soil.【Method】Illumina-miseq high-throughput sequencing technology was used to sequence the V3-V4 region fragments of 16S rDNA gene and the V3-V4 region fragments of fungus 18S rDNA gene in rhizosphere and non-rhizosphere soil of maize in dif-ferent seasons.【Result】High throughput analysis data showed that:(i)the different season maize rhizosphere and non rhizosphere soil physical and chemical properties with the seasons change trend was consistent,maize rhizosphere and non rhizosphere soil conductivity increased before reducing trend with the seasons,general performance for summer>autumn>spring>winter,and maize rhizosphere soil electrical conductivity in different seasons were significantly higher than that of the rhizosphere(P<0.05);From spring to winter,the pH values of maize rhizosphere and non-rhizosphere showed a trend of first decreasing and then increasing,which was roughly manifested as>in spring>in winter>in autumn and summer,and the conductivity of maize rhizosphere soil in different seasons was significantly lower than that in non-rhizosphere(P<0.05).(ii)Different season maize rhizosphere and non rhizosphere soil nutrient content(organic carbon,total nitrogen and total potassium)consistent with the seasons change trend,from spring to winter,maize rhizosphere and non rhizosphere nutrient contents were increased after the first reduce the trend,with the summer maize rhizosphere and non rhizosphere soil nutrient content was the highest,winter maize rhizosphere and non rhizosphere soil nutrient content was the lowest,and fluctuated.(iii)Different season maize rhizosphere and non rhizosphere bacteria and fungi coverage,richness index,Shannon Wiener index and Evenness index Evenness,ACE,Chao 1 index,Simpson in-dex was consistent with the seasons change trend,from spring to winter,rhizosphere and non rhizosphere bacterial and fungal diversity index showed a trend of increase after the first reduce,and different seasons rhizosphere bacterial and fungal diversity index were significantly high-er than that of the rhizosphere.(iv)Maize rhizosphere and non rhizosphere bacteria population,the dominant bacteria mainly deformation,acid bacillus door and bud door bacterium,include mold gate,actinomyces door,bacteroides door,wall ascomycetes door,green curved door after door germs,warts,the relative abundance of rhizosphere bacteria acid bacillus door above the rhizosphere,deformation relative abundance was lower than the rhizosphere bacteria door.In rhizosphere and non-rhizosphere soil fungi communities,the dominant groups were mainly ascomycetes and basidiomycetes,including binding mycetes,chytrid mycetes,neoilifera flagellates,bulb mycetes,and budding mycetes.(v)Correlation analysis showed that there was no significant correlation between corn soil bacteria,fungus Coverage,ACE and soil nutrients(P>0.05).Soil pH was negatively correlated with the diversity of soil bacteria and fungi,while soil conductivity and total phosphorus were not significantly correlated with the diversity of soil bacteria and fungi(P>0.05).【Conclusion】The bacterial and fungal communities in the rhizosphere and non-rhizosphere of maize soil had a good similarity,and the bacterial communities in the rhizosphere and non-rhizosphere had a significant separation effect.