| Blueberry is an important cash crop,its fruit taste and nutrition are good,has broad market prospects.Due to the harsh growing conditions of blueberry fruit trees,the blueberry fruit market has been in short supply.Rhizosphere growth-promoting bacteria can promote plant growth,control plant diseases and improve the soil environment for plant cultivation.In order to reveal the differences in rhizosphere microbial community structure of different varieties of blueberry,the rhizosphere soil microbial diversity of three varieties of blueberry was analyzed in this study.At the same time,selective medium was used to screen rhizosphere growth-promoting bacteria of blueberry,and its promoting effect should be analyzed.In order to provide experimental technical support for the follow-up research on the interaction between blueberry plants and rhizosphere soil microorganisms and the development of blueberry compound bacterial fertilizer.The main research contents are as follows:(1)The microbial community structure and diversity in rhizosphere soil of different varieties of blueberry were studied by culture method.The results showed that Bacillus Was the common dominant bacterium in the rhizosphere of blueberry.The culturable fungi were distributed in 7 genera,among which Penicillium Was the common dominant genus.(2)The use of high-throughput sequencing technology to analyze the structure and diversity of different varieties of blueberry roots soil microbial community structure and diversity.The results of 16 S amplification sequencing showed that Acidobacteria(18.7%),actinobacteria(14.5%)and Proteobacteria(33.3%)were the common dominant phyla of three rhizosphere bacteria of blueberry.The results of diversity comparison were north highbush >South Highbush > rabbit eye,and the results of species richness comparison were south Highbush > rabbit eye > north Highbush.The results of ITS amplification sequencing showed that ascomycota(51.9%)was the common dominant phylum of the three rhizosphere fungi.Rhizosphere fungal diversity was rabbit eye > southern high bush > northern high bush,and species richness was rabbit eye > southern high bush > northern high bush.(3)The selective medium was used to screen the rhizosphere growth-promoting bacteria of blueberry.A total of 16 growth-promoting bacteria were obtained,all of which could produce auxin and have the ability to solve phosphorus,8 had the ability to solve potassium,and 3 had the ability to fix nitrogen.According to 16 Sr DNA,strains P12 and P17 belong to Paraburkholderia,P5,P10,P11,P21,P22,P26,P32,P37 and P41 belong to Pseudomonas,and P6,P7,P24,P40 and P42 belong to Buttiauxella.In the experiment,the growth of blueberry seedlings in 18 groups treated with P5,P6,P7,P21,P22,P24,P26,P40 and P42 were significantly better than those treated with pure water.Compared with the medium control treatment,the number of leaves under P5,P40 and P42 increased by 23.6%,51.2%and 39.9%,the number of branches under P42 increased by 28.6%,the plant height of P24 increased by 11.8%,and the root length under P22 increased significantly by 26.6%.In addition,the chlorophyll content of blueberry leaves under P6,P22 and P42 bacterial solution increased by 45.06%,63.6% and 47.3%,respectively,compared with the medium treatment.(4)By studying different biochemical treatment,the base of the blueberry root soil microbial community structure and the nature of soil can analyze the impact of different biochemical fungus on the soil.The results of rhizosphere microbial detection showed that Proteobacteria and Acidobacteriota were the dominant bacterial phyla in all treated rhizosphere soil.P5 and P42 strains significantly reduced the rhizosphere bacterial richness,P24 strains increased the rhizosphere bacterial diversity,and P22 strains decreased the rhizosphere bacterial diversity.Basidiomycetes and ascomycetes were the dominant fungal phyla in all treatments of blueberry rhizosphere soil.P5 decreased the richness of rhizosphere soil fungal community,P42 and P40 significantly increased the richness of rhizosphere soil fungal community,and P6,P21 and P42 significantly increased the diversity of rhizosphere soil fungal community.The results of soil element detection showed that the contents of total P,available P,total K,available K and organic matter in rhizosphere soil of blueberry treated by 9 strains and control medium were higher than those of pure water treated.The contents of total P and available P were the highest in the soil treated with P22 strain,total K was the highest in the soil treated with P21 strain,available K was the highest in the soil treated with P24 strain,and organic matter was the highest in the soil treated with P40 strain. |
