Study On Diversity Of Soil Nematodes And Nutrient Microorganisms In Soil Covered Cultivation Process Of Pleurotus Citrinopileatus

In the cultivation process of edible fungi fermentation material,the beneficial microorganisms in the culture material play an important role in degrading straw and promoting the growth of mycelium.At the same time,some harmful microorganisms limit the growth of mycelium and affect the yield of edible fungi.Soil-covering cultivation is widely used in the cultivation of edible fungi because of its ability to improve the quality of edible fungi and enhance the disease resistance of edible fungi.The change of soil nematode community composition can have different effects on the growth of edible fungi.At present,there is no systematic study on the culture microorganisms and soil nematodes in the soil-covered cultivation of Pleurotus citrinopileatus fermentation materials.The research on the mechanism of the diversity characteristics of the microbial community in the cultivation process of Pleurotus citrinopileatus also needs to be further explored.In this study,different animal manures were used as culture materials to cultivate Pleurotus citrinopileatus,and culture materials samples at different cultivation stages were collected.The 16 S r RNA(bacteria)and ITS(fungi)gene fragments were obtained by high-throughput sequencing.Based on this,the diversity of fungi and bacteria in the culture materials during the cultivation of Pleurotus citrinopileatus was explored.Through the isolation and identification of nematodes in soil samples with different fruiting tides in the process of soil-covering cultivation,the abundance of soil nematodes was analyzed,and the community composition was analyzed by calculating Shannon-Wiener diversity index,dominance index / Simpson index and richness index,in order to explore the response and indication of soil nematodes in the process of soil-covering cultivation of Pleurotus citrinopileatus.The results show that :The analysis results of Alpha diversity and Beta diversity of bacteria and fungi were not significantly different among the deer manure group,the chicken manure group and the mixed group.At the level of bacterial phylum,Proteobacteria,Actinobacteria and Firmicutes were the dominant phylum at different stages of culture.At the phylum level,Ascomycota and Basidiomycota were the dominant phylum at different stages of the culture medium.Fungi are mainly involved in the degradation of substrate,and bacteria play an important role in straw degradation,mycelial growth and fruiting body formation.By comparing the abundance of bacterial genera such as chelococcus,thermophilic bacillus and fungal genera such as trichothecium and aspergillus in the pre-wetting stage and fermentation stage,it was found that the degradation effect of chicken manure group on corn straw was stronger than that of deer manure,and in the mycelium colonization stage,chicken manure group could still degrade corn straw efficiently.By comparing the contents of Acinetobacter,Pseudomonas,Bacillus,Microbacterium,Rhizobium and Pleurotus in the mycelium colonization stage and the fruiting body formation stage,it was found that the mixed group of deer manure and chicken manure had a stronger effect on the promotion of mycelium than the deer manure group and the chicken manure group,but the chicken manure group had a stronger ability to promote the formation of fruiting bodies than the deer manure group and the chicken manure group.A total of 34 genera of soil nematodes were identified in soil samples,including8 genera of plant parasitic nematodes.There are 7 genera of fungivores;there are 11 genera of bacterivores;there are 5 genera of predatory/omnivorous nematodes.The soil nematodes in the mixed group of deer manure,chicken manure and deer manure chicken manure maintained a high relative abundance at the initial stage of soil covering.The number of nematodes decreased during the first tide.With the increase of fruiting tides,the abundance of plant parasitic nematodes and fungivores in deer manure group,chicken manure group and mixed group increased first and then decreased.Predator/omnivorous nematodes and bacterivorous nematodes showed no obvious regularity,only the abundance of bacterivorous nematodes in the mixed group decreased gradually with the increase of fruiting tide,and the abundance of predator/omnivorous nematodes in the deer manure group increased gradually with the increase of fruiting tide.This study revealed the changes of culture materials and soil during the cultivation of Pleurotus citrinopileatus from the aspects of microbial diversity and nematode community structure.It has positive significance for the scientific domestication and efficient cultivation of Pleurotus citrinopileatus,and provides reference data for the cultivation and growth mechanism of Pleurotus citrinopileatus and the indication of nematodes.