| Rhizosphere microbial community is of great significance for regulating the global biogeochemical cycle,promoting plant growth and development,and improving the adaptability of plants to the environment Ningxia grassland is an ecological barrier in northwestern China.Stipa species,as the dominant and constitutive species in Ningxia grassland,provide an ideal place for the study of microbe diversity in the rhizosphere of Stipa.However,There are few research reports on microbial diversity of Stipa rhizospher,and related research can provide scientific basis and theoretical support for ecological restoration and management of Ningxia grasslandIn this study,rhizosphere soils of Stipa species were sampled at 15 sites across a large geographical region of their distribution,along steppe types.Community structure and diversity of fungi and bacterial in the rhizosphere soil of Stipa species were measured by high-throughput sequencing technology.Relationships between rhizosphere fungal and bacterial community structure and diversity were analyzed in relation to spatial,climatic and soil factors.We found that:(1)The fungus was detected to have 8 phylum,25 classes,61 orders,136 families,218 genera;the bacteria have 24.phylum,68 classes,146 orders,247 Branch,462 genus.The total number of soil fungus OTUs in all plots was 8947,and the total bacterial OTUs was 19764.(2)At the phylum level,the dominant rhizosphere fungi of Stipa species were Ascomycot(41.04%?87.31%)and Basidiomycota(5.24%?37.26%);The dominant bacterial were Proteobacteria(28.22%?50.18%),Actinobacteria(10.12%?33.94%)and Acidobacteria(2.06%?18.34%).(3)The diversity of rhizosphere fungi and bacteria of Stipa species varied,but the difference were not significant Combined with the results of Rarefaction Curve and Rank-Abundance,it can be observed that the rhizosphere bacterial diversity of Stipa species were more abundant than that of fungi.(4)In the analysis of Beta diversity,PCoA and UPGMA cluster analysis were used to analyze the differences in fungal and bacterial community structure among samples,and it was found that there were certain differences in the structure of rhizosphere bacteria and bacterial community in the Stipa species.(5)RDA analysis showed that ecological factors can explain the variance of 89.75%of the rhizosphere fiungal community composition of Stipa species,in which pH,TOC,TN,AN and SWC(p<0.05)were the main factors affecting the fungal community structure.The ecological factors could explain the variance of 98.26%of the bacterial community composition in rhizosphere soil of the Stipa,among which FL,SL,TP,AP,LAT and SRAD(p<0.05)were the main factors affecting the bactarial community structure.(6)The correlation analysis of rhizospheric microbial diversity and ecological factors showed that bulk density and soil particle size were the leading factors affecting soil fungal diversity index.Organic matter and total nitrogen were the main driving factors affecting soil bacterial diversity index.Our results were of great significance to the sustainable development and management of grasslands in Ningxia.It can provide basis for improving grassland soil fertility and soil function... |
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