Study On Microbial Community Diversity Of Eucommia Ulmoides Soil

Eucommia ulmoides Oliv.,a traditional medicinal plant unique to China,has rich E.ulmoides rubber in its bark.It is the main source of E.ulmoides rubber in industrial production and possesses high medicinal and economic value.Soil microorganisms play a significant role in the material cycling,energy flow,and interactions among organisms in E.ulmoides forest ecosystems.They are crucial factors affecting biodiversity,accumulation of medicinal active substances,and economic value of E.ulmoides forests.Exploring the soil microbial community structure and ecological functions in E.ulmoides forests can provide technical support for intensive cultivation management and quality improvement of E.ulmoides products.In this study,soil samples were collected from E.ulmoides forests of different ages in Changji and Kuitun in Xinjiang,as well as the demonstration area in Yangling,Shaanxi.High-throughput sequencing technology and soil physicochemical property analysis were used to investigate the diversity of soil microbial community structure and its ecological functions in different locations and age groups of E.ulmoides forests.Redundancy analysis was used to study the correlation between microbial communities and soil nutrients.The core microbial community in E.ulmoides soil was defined using a membership analysis method combined with composition accounting.FAPROTAX and FUNGuild were used to predict the potential functions of soil microbial communities.The main research findings are as follows:(1)Exploration of soil microbial communities of E.ulmoides in different production areas.The dominant bacterial phyla in soil microbial communities of E.ulmoides forests from different locations are Proteobacteria,Actinobacteria,and Acidobacteria.The dominant fungal phyla are Ascomycota,Zygomycota,and Basidiomycota.The relative abundances of these phyla vary significantly among different locations.Alpha diversity analysis reveals that the ranking of Shannon diversity index for bacteria in E.ulmoides soil from Changji(CJ2),Kuitun(KT2),Yangling(YL2,YL30)is as follows,from high to low: CJ2(6.65)> KT2(6.62)> YL2(6.53)> YL30(6.09).The ranking of Shannon diversity index for fungi is as follows,from high to low: YL30(4.04)> YL2(3.96)> KT2(3.70)> CJ2(3.17).RDA analysis indicates that the distribution of bacterial communities in E.ulmoides soil is significantly correlated with soil nutrients.Total potassium(p=0.001)and total phosphorus(p=0.002)are the main factors influencing the distribution of bacterial communities among different locations.Among different locations,exchangeable potassium(p=0.002)has the strongest influence on the distribution of fungal communities.(2)Exploring the microbial community in E.ulmoides soil of different planting years.There were significant differences(p<0.05)in soil nutrient contents among different age stands of E.ulmoides.With increasing planting age,the organic matter,total nitrogen,and available potassium content in E.ulmoides soil increased continuously,while total potassium,total phosphorus,and available phosphorus content initially increased and then decreased.The soil microbial community structure also showed significant differences among different planting years.At the phylum level,the relative abundances of Acidobacteria,Proteobacteria,Planctomycetes,Actinobacteria,Ascomycota,Bacteroidetes,and Basidiomycota varied significantly(p<0.05)among different planting years of E.ulmoides soil.The α diversity analysis showed that the Shannon index values of bacterial communities in E.ulmoides soil,ranked from high to low among different stand ages,are as follows: DY30(7.12)= DQ30(7.12)> DY3(6.94)> DQ50(6.92),and the Shannon index values of fungal communities in E.ulmoides soil,ranked from high to low among different stand ages,are as follows: DQ50(4.43)> DY30(4.36)> DQ30(4.21)> DY3(3.06).RDA analysis revealed that the distribution of bacterial communities in E.ulmoides soil varied significantly with different stand ages and was significantly associated with soil nutrients.Among these nutrients,total phosphorus and available phosphorus were identified as the most important factors influencing the bacterial community composition in different planting ages(p=0.001).However,no significant correlation was observed between fungal community distribution and the soil nutrient indicators measured in this study(p>0.05).(3)Prediction and evaluation of microbial community function in E.ulmoides soil.Functional analysis of soil microbial communities in E.ulmoides was conducted using the FAPROTAX and FUNGuild prediction methods.The results showed significant differences(p<0.05)in the relative abundances of bacterial communities associated with chemoheterotrophy,aerobic chemoheterotrophy,fermentation,ureolysis,aerobic ammonia oxidation,nitrate reduction,respiration of sulfur compounds and sulfate respiration among different locations.The functional groups of beneficial mycorrhizal fungi and plant pathogenic fungi also exhibited significant differences(p<0.05)among different locations.Furthermore,significant differences(p<0.05)were observed in the relative abundances of bacterial communities associated with chemoheterotrophy,aerobic chemoheterotrophy,aliphatic non methane hydrocarbon degradation,aromatic hydrocarbon degradation and hydrocarbon degradation among different ages.As the age of the forest increases,the relative abundance of plant pathogenic fungal groups continues to increase,while the relative abundance of beneficial mycorrhizal fungal groups decreases significantly in over-mature forests.