| ?OBJECTIVE?Stipagrosits pennata is an important pioneering sand-fixing plant in the flow and semi-mobile sand areas of the Gurbantunggut Desert.It plays an extremely important role in sand fixation,plant succession in the sand area,and maintenance of local ecological balance.The presence of the root sheath is a limiting factor for the maintenance of metabolism of the Stipagrosits pennata,while the microorganisms involved in the formation of the root sheath are diversified.The aim of this study was to elucidate the diversity and abundance of endophytes in the Stipagrosits pennata;the abundance of functional bacteria;the diversity and abundance of root microbes,plant phenotypes and their relationship.?METHODS?In this paper,five plots with distant geographical locations were used to collect Stipagrosits pennata,seeds,roots,root sheaths and root-soil soils.The traditional methods and culture-free methods were used to study the endophytic microorganisms and root sheaths of Stipagrosits pennata.Microbial and microbial diversity;the abundance of functional microorganisms was studied by isolation and identification;the phenotype was determined to understand the diversity of the external morphology of the Stipagrosits pennata and its correlation with the root microorganisms.?RESULTS?Among the endophytic microorganisms of Stipagrosits pennata,(1)endophytic bacteria can be initially classified into 2 families,2 classes,2 orders,2 families and 2 genera;(2)endophytic bacteria can be initially classified as 1 and 1 2 families and 2 genera;(3)4 kinds of seed endophytic fungi and 11 root endophytic fungi were screened by dilution coating method and scribing method.In the microbes of the Stipagrosits pennata and roots,the root sheath samples in the sample area were distributed in two genera of bacteria,accounting for 0.71% and 4.26% of all root sheath bacteria,respectively,accounting for 0.45% and 2.68% of all root bacteria,respectively.For the genus Bacillus.The root circumference samples in the plot 1 were distributed in 2 genera of bacteria,accounting for 4.82% and 1.20% of all root bacteria,respectively,accounting for 1.79% and 0.45% of all root bacteria,respectively.The dominant genus was Bacillus.The root sheath samples in plot 2 were distributed in 5 genera of bacteria,accounting for 11.35%,6.38%,7.80%,2.13%,and 0.71% of all root sheath bacteria,respectively,accounting for 7.14% and 4.02% of all root bacteria,respectively.4.91%,1.34%,0.45%,the dominant genus is Bacillus.The root circumference samples in plot 2 were distributed in three genera of bacteria,accounting for 1.20%,10.84%,and 3.61% of all root bacteria,respectively,accounting for 0.45%,4.02%,and 1.34% of all root bacteria,respectively.Bacillus.The root sheath samples of the three plots were distributed in 6 genera of bacteria,accounting for 4.26%,2.13%,6.38%,2.84%,0.71%,and 7.09% of all root sheath bacteria,respectively,accounting for 2.68% of all root bacteria.1.34%,4.02%,1.79%,0.45%,4.46%,the advantage belongs to the genus Pantoea.The root circumference samples of the three plots were distributed in two genera of bacteria,accounting for 1.20% and 30.12% of all root sheath bacteria,respectively,accounting for 0.45% and 11.16% of all root bacteria,respectively.The dominant species belonged to the genus Pantoea.The root sheath samples of the four plots were distributed in six genera of bacteria,accounting for 0.71%,8.51%,4.26%,1.41%,2.13%,and 1.42% of all root sheath bacteria,respectively,accounting for 0.45% of all root bacteria.5.36%,2.68%,0.89%,1.34%,0.89%,the dominant genus is Bacillus.The root circumference samples of the four plots were distributed in four genera of bacteria,accounting for 21.69%,1.20%,1.20%,and 2.41% of all root bacteria,respectively,accounting for 8.04%,0.45%,and 0.45% of all root bacteria.0.89%,the dominant genus is Bacillus.The root sheath samples of the five plots were distributed in 8 genera of bacteria,accounting for 3.55%,1.42%,4.26%,9.22%,0.71%,0.71%,3.55%,and 1.42% of all root sheath bacteria,respectively.The root bacteria were 2.23%,0.89%,2.68%,5.80%,0.45%,0.45%,2.23%,and 0.89%,and the dominant genus was Acinetobacter.The root circumference samples of the five plots were distributed in 7 genera of bacteria,accounting for 3.61%,2.41%,2.41%,1.20%,3.61%,1.20%,and 1.20% of all root bacteria,respectively,accounting for all root bacteria.1.34%,0.89%,0.89%,0.45%,1.34%,0.45%,0.45%.The dominant genus is Pseudomonas and Pantoea.In summary,no matter which kind of OTU microorganisms,the number of root sheaths is larger than the root circumference,and the number of bacteria roots is 1.70 times of the root circumference.But with the difference in the plot,the abundance of bacteria showed an irregular change.Changes in microbial diversity can reflect the changes in soil quality earlier and have an important indicator of ecological environment evolution.Therefore,it is important to clarify the role of microbial communities in different environments and to understand their community composition and structural changes for the study of the entire ecosystem.The phenotypic traits of Stipagrosits pennata showed that the phenotypic variation was rich,the average coefficient of variation of traits was 79.51%,and the variation range was 17.28% ~ 178.91%.The variation coefficient of plant cluster height was the smallest,and the number of seeds per plant was the largest.Principal component analysis showed that 16 traits could be combined into four main components,such as plant growth and development,reproduction degree,which were basically consistent with the system clustering results,indicating that these four principal components can basically reflect the feather phenotype.The overall situation of variation.There was a significant positive correlation between most traits,and the correlation between the number of leaves and the final number of tillers was the highest(r = 0.84),and the number of primary effective tillers and secondary effective tillers(r = 0.80),indicating between traits.It is synergistic for environmental adaptation.Among the populations,some traits were significantly different(p < 0.01),and the aggregation trend appeared in the principal component map.The rich phenotypic variation of Stipagrosits pennata is the result of interaction with the environment,which constitutes an important basis for adapting to desert drought,windy,high temperature,mobile sand and other adversities,and has a background in plant succession and improvement of sandy environment.An important role in understanding the microbes and phenotypes to understand the reasons why Stipagrosits pennata can fix sand in extreme desert environments.The rich phenotypic variation of Stipagrosits pennata is the result of interaction with the environment,which constitutes an important basis for adapting to desert drought,windy,high temperature,mobile sand and other adversities,and has a background in plant succession and improvement of sandy environment.Important role.Phenotypic association analysis(CCA/db-RDA analysis)showed that the correlation between the number of primary tillers and community distribution and species distribution was the largest;the correlation between the number of secondary tillers and community distribution and species distribution was the smallest,indicating that the number of primary tillers may be It is one of the determinants of community structure.?Conclusion and significance?In order to explore the composition of the symbiotic microbes of the Stipagrosits pennata and their adaptation to the desert environment,464 strains of bacteria and 81 strains of fungi were isolated from the seeds,roots,root sheaths and roots.The study found that:(1)The root sheath microorganisms are closely related to the growth of Stipagrosits pennata;(2)microorganisms with nitrogen-fixing function predominate;and(3)microorganisms are significantly associated with the phenotype of Stipagrosits pennata.This paper enriches the symbiotic microbial resources of the Stipagrosits pennata and peony,and preliminarily clarifies the association between the symbiotic microbes of the Stipagrosits pennata and their phenotypes. |
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