Study On The Effect Of Soil Microorganisms Related To Soybean Root Region On Phosphorus Transformation

Phosphorus is one of the main limiting nutrients for soybean growth.It regulates its growth and development.Plants,soil physical and chemical properties and microorganisms are the key factors that affect the transformation of different forms of phosphorus.The soil area of plant roots is the most active area of soil microbial activity.The research on the role of microorganisms in the transformation of soil phosphorus has made great progress,and many phosphate-dissolving bacteria have been isolated.At present,there are few studies on the relationship between root microbial communities and different forms of phosphorus transformation from the perspective of microbial communities.From the perspective of microbial community,the relationship between root microbial community and different forms of phosphorus transformation is relatively small.The relationship between soil phosphorus content,soil physical and chemical properties and soil microbial community is established to study the process of phosphorus transformation.You can quickly find taxonomic groups related to phosphorus conversion,and provide a basis for the subsequent separation of functional flora.In this study,the typical red and acid farmland soil in Guilin was used as a cultivation substrate for soybean(Zhonghuang 13)pot experiment,combined with high-throughput sequencing technology to study the succession pattern of bacterial and fungal communities in soybean root soil.Study the dynamic changes of different forms of phosphorus content,soil physicochemical factor content and the total amount of bacteria and fungi.To analysis the relationship between root microbial community,soil physicochemical and transformation of phosphorus.The following results are obtained:(1)The spatial succession pattern of bacterial and fungal community structure in soybean root area is similar and both are affected by the root environment and growth period.From bulk soil to rhizosphere,the succession of microbial communities is a spatially gradual process,root zone can be regarded as intermediate zone of the microbial community transition.Due to the effects of spatial distance and environmental effects,the soil area closer to the root is more susceptible to plant regulation,and the rhizosphere community structure and diversity and species abundance change more significantly than root zone and bulk soil with the extension of plant growth.The variation of the community structure from bulk soil to root zone is small,but the interaction between the members of the community has changed greatly.It is speculated that the change in the interaction between the microorganisms may precede the change in the community structure,and this change in interaction may cause changes in community structure.Although the spatial succession patterns are similar,the surrounding environment of the root system has a stronger gradient selection effect on bacterial communities than fungi.(2)There are significant differences of different forms of phosphorus content in different root area and soybean growth time.Affected by various factors such as soil physicochemical and microbial,different forms of phosphorus components are transformed into each other.There are some differences in the conversion process between the 9 forms of phosphorus components in root zone and bulk soil.Among various forms of inorganic phosphorus,calcium phosphate(Ca-P)and closed storage phosphorus(OP)are more converted into iron phosphate(Fe-P)and aluminum phosphate(Al-P)in root zone,and further converted into available phosphorus(AP).In organic phosphorus,more active organic phosphorus(A-OP)in root zone will be converted from other forms of phosphorus,and further converted into AP.In the typical red and acid soil of Guilin area,the content of Fe-P in inorganic phosphorus is the highest.With the increase of soybean growth time,the increase of Fe-P in the soil of the root zone shows a significant upward trend.Therefore,it is beneficial to the formation of Fe-P in the root zone under the influence of soybean and soil microbial activities.Soil organic matter(OM),total nitrogen(TN),total carbon(TC),p H,nitrate nitrogen(NO3--N),and ammonium nitrogen(NH4+-N)affect the conversion of specific forms of phosphorus through direct or indirect effects.(3)The differences in the microbial community structure and abundance of root zone and bulk soil have different correlations with the changes of various forms of phosphorus transformation process.Among them,there is a strong correlation with the conversion process of various forms of organic phosphorus,but the correlation with the conversion of inorganic phosphorus and the increase of AP content is not significant.The taxa related to phosphorus transformation overlapped with those related to the differences in the structure of soil microbial communities in root region.Especially in soil bacterial community,plant roots had a higher selection effect on the bacterial group related to phosphorus transformation than fungi.There are 210(348)and 11(10)OTU in bacterial and fungal communities associated with the phosphorus transformation process,which are enriched in the rhizosphere(decreased abundance).These taxons may participate in the rhizosphere phosphorus transformation process.The results of this study further deepened the understanding of the spatial succession patterns of bacterial and fungal communities in root area,and provided a basis for the subsequent study of different forms of phosphorus transformation mechanisms and the targeted separation of specific forms of phosphorus transformation bacteria in farmland soil.