Changes Of Rhizosphere Microorganisms And Phenolic Acids In Polygonatum Odoratum Under Continuous Cropping

Polygonatum odoratum(Mill)Druce is a perennial herb of the genus Liliaceae.It has high medicinal value and nutritional value and is a kind of medicinal plant with great development value.Because P.odoratum has a very serious continuous cropping obstacle,it directly affects the farmers’ harvest and restricts the healthy and sustainable development of P.odoratum industry.Soil microorganisms have a very important role in improving soil quality.However,few studies have involved changes in rhizosphere microorganisms and phenolic acid secretions in P.odoratum.This paper mainly uses the pot experiment to study the changes of the growth of P.odoratum under continuous cropping conditions.The microbial culture method was used to study the changes of microbial community in the rhizosphere of P.odoratum under continuous cropping conditions.The rhizosphere soil.The changes of phenolic acid-sensing substances in the phenolic acid was determined by high performance liquid chromatography and explored the effects of phenolic acid-sensing substances on the growth of Fusarium oxysporum.in order to provide a theoretical basis for the study of P.odoratum continuous cropping obstacles.The main results are as follows:(1)Continuous cropping caused the emergence time,seedling time,leaf-expanding period and flowering period of P.odoratum,the plant height became shorter,the number of leaves decreased,and the mortality after continuous cropping reached 35.83%,which was 22.50% higher than that of the first harvest.(2)The number of cultivable bacteria,fungi and actinomycetes in the rhizosphere soil of P.odoratum was higher than that of the first harvest.The average number of culturable bacteria in the rhizosphere soil of P.odoratum was19919.17 CFU/μL,and the first harvest was 357.94 CFU/μL.The average number of culturable fungi in the rhizosphere soil of the continuous crop was 211.21 CFU/μL,and the first harvest was 44.23 CFU/μL.The average number of cultivable actinomycetes in the root system of P.odoratum was 6528.09 CFU/μL,and the first harvest was 5235.42 CFU/μL.(3)The content of five phenolic acids in the rhizosphere soil of P.odoratum was higher than that of the first harvest of P.odoratum.The content of p-hydroxybenzoic acid,vanillic acid,syringic acid,coumaric acid and ferulic acid in the rhizosphere soil of P.odoratum was: 0.1372 μg/g,0.3003 μg/g,0.0590 μg/g,0.0385 μg/g,0.0303 μg/g,the contents of p-hydroxybenzoic acid,vanillic acid,syringic acid,coumaric acid and ferulic acid in the rhizosphere soil of P.odoratum were 0.0554 μg/g,0.2806 μg/g,0.0337 μg/g,0.0204 μg/g,and0.0187 μg/g.(4)The five phenolic acids have a strong allelopathic effect on the mycelial growth rate and spore germination rate of F.solanii,which is characterized by low concentration to promote growth and high concentration to inhibit growth.