Background: There are serious obstacles to continuous cropping of Gastrodia elata. After continuous cropping of Gastrodia elata, the yield will be greatly reduced, or even no harvest. Soil nutrients and microorganisms play an important role in it. There are few related studies on the effects of natural restoration of the rhizosphere soil of Gastrodia elata on the structure of soil bacteria and fungi for different years.
Results: In this study, a combination of Illumina Miseq library preparation and high-throughput sequencing technology was used. The soil that had not been planted with Gastrodia elata was used as a control to study the characteristics of soil microbial communities in the rhizosphere of Gastrodia elata from 0 to 5 years of natural restoration, and Correlation between soil characteristics and fungal and bacterial communities. The results showed that (1) The dominant bacteria in the rhizosphere soil of Gastrodia elata are roteobacteria, Actinobacteria and Acidobacteria, and the most important bacterial genera are norank_f_Xanthobacteraceae and Bradyrhizobium. The dominant fungal phyla are Basidiomycota and Ascomycota, and the main fungal genera are Mortierella and Trichoderma. The bacterial and fungal community composition in the rhizosphere soil of Gastrodia elata and the soil without Gastrodia elata planted are not much different, but the community structure and relative abundance are quite different. (2) The Chao index, Shannon index and Invsimpson index of Gastrodia elata rhizosphere soil show an increasing trend with the increase of the natural restoration period, indicating that natural restoration for a certain period of time will increase the diversity and abundance of bacteria and fungi in the rhizosphere soil of Gastrodia elata Increase. (3) With the increase of the natural restoration period, the total nitrogen and pH content of the rhizosphere soil of Gastrodia elata showed an increasing trend. total nitrogen has the greatest influence on the bacterial community structure, and the influence of pH on the fungal community structure ranks No. Second, in the top three phyla with relative content, total nitrogen is positively correlated with Actinobacteria, and pH is positively correlated with Mortierellomycota.
Conclusion: After 3 years of natural restoration, the soil environment gradually returns to normal, and the microbial community tends to balance; in addition, the Spearman rank correlation coefficient analysis shows that total nitrogen has the greatest impact on the bacterial community structure in the rhizosphere soil of Gastrodia elata, and total phosphorus has the greatest impact on the fungal community structure. The results provide a theoretical basis for the development of new type microbial fertilizers and soil amendments for Gastrodia elata to alleviate continuous cropping obstacles.