Diversity Of Actinomycetes In Rhizosphere Soil Of Alpine Rhododendron In Luquan And Qiaojia

Actinomycetes is a kind of Gram-positive bacteria with high(G + C)mol%,which is named after its colony as a radial line.Actinomycetes are the largest class in the bacterial domain,and there are many species under its door.Actinomycetes are closely related to human life and production.It has strong metabolic ability.The natural metabolites of actinomycetes mainly include immunosuppressants,pesticides,antibiotics,anti-tumor and so on.At present,in clinic and medicine,most antibiotics come from metabolites produced by actinomycetes.Rhizosphere microorganism is a kind of microorganism in plant roots and surrounding soil.The diversity of plant rhizosphere microorganisms is very high.Rhizosphere microorganisms interact with each other and become a small ecosystem.When the population structure of rhizosphere microorganisms changes,plant growth will also change.China is the distribution center of Rhododendron,with about 460 species.The Rhododendron varieties in Yunnan account for more than half of the national varieties.The excavation of Rhododendron rhizosphere Actinomycetes Resources in Yunnan has important scientific significance and application valueIn this study,the rhizosphere soil actinomycetes of Luquan jiaozi snow mountain and Qiaojia Dabai road Liangzi Rhododendron were studied.A total of 17 Rhododendron rhizosphere soil samples from Luquan County and Qiaojia county of Yunnan Province were collected.The diversity of actinomycetes was studied by means of free culture and pure culture.At the level of free culture,the primers of v4-v5 region of bacterial 16 S rRNA gene were used for amplification,and the miseq pe300 platform was used for sequencing.High throughput sequencing and bioinformation analysis technology were used to explore the diversity and community structure of actinomycetes in rhizosphere soil of Alpine Rhododendron;At the pure culture level,explore the pure culture and separation effect of actinomycetes under antibiotic stress,and tap actinomycete resources to provide strain resource guarantee for the utilization of actinomycete resources in the future.The results of culture free study showed that the microorganisms detected in eight soil samples in Qiaojia county were distributed in 34 phyla,94 classes,214 orders,323 families and 532 genera(data after de duplication);A total of 9 soil samples from Luquan County were tested for microorganisms distributed in 36 phyla,100 classes,225 orders,348 families and 592 genera.Acidobacteriota accounts for the highest proportion at the door level,reaching 29.7%.Followed by Actinobacteria accounting for 24%,Proteobacteria accounting for 21.5% and Chloroflexi accounting for 19%.At the genus level,norank is the most,accounting for 8.6%,followed by Xanthobacteraceae,accounting for 6.7% and Acidothermus,accounting for 6.5%.The results of pure culture showed that 238 culturable strains were obtained,including 80 actinomycetes and 158 bacteria,which were distributed in 4 phyla,20 classes,29 orders,50 genera and 93 species,including 14 candidate new species.Actinomycetes are isolated from 12 orders,genera and families.Actinomycetes strains from jiaozi snow mountain in Luquan County include 9 genera,including 15 genera of Streptomyces,accounting for 52.6%,5 genera of Kitasatospora,accounting for 15.6%,and 3 genera of Streptosporangium,accounting for 9.3%;There are 9 genera of actinomycetes in Dabai Luliang,Qiaojia county,including 20 genera of Streptomyces,accounting for 48.7%,4 genera of Microbacterium,accounting for 10%,and 3 genera of Rhodococcus,accounting for 7.5%.The similarity between the two places is very high,and the common main groups are Streptomyces,Rhodococcus and Arthrobacter.Nocardia and leifsonia are the unique actinomycetes of Rhododendron rhizosphere soil samples in Luquan County,while jiangella and Brachybacterium are the unique actinomycetes of Qiaojia Rhododendron rhizosphere soil samples.The separation effect of culture medium was evaluated as T3 medium > Gauss medium > nitrogen fixing medium;The isolation effect of antibiotics was evaluated as erythromycin +vancomycin medium > erythromycin medium > vancomycin medium;During the isolation process,the culturable results showed that the experimental results showed that the probability of new groups of actinomycetes isolated under antibiotic stress was high,which provided a new idea for the isolation method of actinomycetes.In this study,the diversity of actinomycetes in rhizosphere soil of Alpine Rhododendron in Luquan and Qiaojia was studied by means of free culture and pure culture.The results showed that the actinomycete resources of Rhododendron rhizosphere soil samples in Luquan County and Qiaojia county of Yunnan Province had great potential.