Study On Microbial Community Structure And Species Diversity In Two Cultivation Substrates Of Potato

Potatoes are the fourth largest non-cereal crop in the world and play a pivotal role in global agriculture.As a major potato-producing country,China has the highest production and planting area in the world.However,traditional cultivation methods have adverse effects on potato health due to the complex and diverse soil environment.Therefore,soilless cultivation technology has emerged as an effective solution to this problem.This method offers the advantages of simplicity,convenience,and improved control of the potato growth environment,leading to higher yield and quality,as well as conservation of resources and environmental protection.While many studies have focused on potato planting and cultivation,there is limited research on the microbial community structure and species diversity in potato cultivation substrates.Therefore,this study aims to investigate changes in the microbial community structure and species diversity in two different potato cultivation substrates,and to analyze the relationship between potato rhizosphere and microorganisms under differing treatment conditions.The findings of this study will provide valuable data for the development of solid substrate cultivation methods for potato production.The main research contents are as follows:1.Through measurements of physical and chemical properties on 7 groups of substrates,including untreated coconut coir(A)and vermiculite(D)substrate samples;coconut coir(B)and vermiculite(E)substrate samples fermented for 3 days after adding base fertilizer;coconut coir(C)and vermiculite(F)substrate samples obtained after planting potato seedlings for 50 days after adding base fertilizer;substrate(G)obtained by mixing coconut coir and vermiculite,adding base fertilizer,and planting potato seedlings for 50 days,we measured data for a total of 12 physical and chemical factors.It was found that there were significant differences in the basic physical and chemical properties between coconut coir and vermiculite substrates.After planting potatoes,except for p H and available potassium(AK)in coconut coir substrate,all other physical and chemical factors in both substrates decreased.In addition,in the G group containing both coconut coir and vermiculite substrates,except for electrical conductivity(EC)and water-soluble nitrogen(WSN),all other physical and chemical factors were closer to the F group.2.Detection and analysis of bacteria in the substrate revealed significant differences in bacterial species abundance and diversity among different substrates.The addition of base fertilizer and planting of potatoes were found to decrease the abundance and diversity of bacteria in the substrate.Community composition analysis revealed that the dominant bacterial phyla in coconut coir substrate were Proteobacteria and Actinobacteria,and their relative abundance increased after two treatments,but the abundance of Actinobacteria decreased.Firmicutes and Verrucomicrobia were more responsive to potato planting.In vermiculite substrate,the dominant phyla were Proteobacteria,Actinobacteria,Firmicutes,and Acidobacteria,but the composition of the community changed dramatically after base fertilizer and planting treatment,with Acidobacteria almost disappearing and the abundance of Actinobacteria increasing.3.Detection and analysis of fungal diversity found no significant difference in species abundance among the groups.After two treatments,fungal species diversity in coconut coir substrate was significantly reduced.In vermiculite substrate,only the fungal species diversity in the substrates planted with potatoes was significantly reduced.Community composition analysis found that the fungal composition in coconut coir substrate was less complex than in vermiculite,with Ascomycota and Basidiomycota being the main dominant phyla distributed in all groups of substrates.In coconut coir substrate,the response of Ascomycota and Basidiomycota to base fertilizer treatment was more obvious,and recovered to their original levels after planting potatoes,while the abundance of Glomeromycota and Rozellomycota fungi increased.In vermiculite substrate,the fungal response to potato planting treatment was significant for Ascomycota,Basidiomycota,and Oomycota fungi.4.Through variance partitioning analysis(VPA),the results showed that the microbial community in the substrate was affected by both physical and chemical factors,with the chemical factors having a much greater impact than the physical factors.RDA(redundancy analysis),CCA(canonical correlation analysis),and Spearman analysis showed a significant correlation between different physical and chemical factors and the microbial community structure.5.It was found that different substrates have different effects on potato growth.In coconut coir substrate,more plant growth-promoting bacteria(PGPR)were enriched in the potato rhizosphere,while more pathogenic fungi were enriched in vermiculite substrate.In addition,the microbial communication in coconut coir substrate was more intense,showing higher negative correlation,which created a more favorable microbial environment for plant growth.The integrated physiological data and microbial community evolution analysis indicated that coconut coir substrate was more conducive to the plant height and tuber number of potatoes.Therefore,this study has important reference value for the selection and optimization of solid cultivation substrates for potato growth.