Study On Isolation And Identification Of Endophytes From Chrysanthemum Morifolium Cv.Boju And Their Antibacterial And Growth Promoting Functions

In this study,endophytes were isolated from the Chrysanthemum morifolium cv.BoJu,and some strains were identified by means of molecular biology and morphological observations.Endophyte strains with agricultural value were screened out,which will lay an important foundation for future development and application in agriculture.The main contents and results of this study are as follows:1.A number of samples of the Chrysanthemum morifolium cv.Boju were collected from the three marigold planting bases in Bozhou.The separation of endophytic strains from the Chrysanthemum morifolium cv.BoJu plants was performed.56 endophytic strains were isolated from the roots,stems,leaves and flowers of Cinnamomum erinaceus,including 31 bacteria and 25 fungi.2.Antagonism of endophyte strains against Curvularia lunata,Fusarium oxysporum,Fusarium graminearum,Fusarium moniliforme,Pestalotiopsis theae and Colletotrichum lagenarium were evaluated by plate confrontation assay.It was found that 20% endophytes had obvious antagonism against at least one plant pathogen.The strains BN3,BN7,BN14 and BJF10 had broad antimicrobial spectrum on plant pathogens.BN3 had the best antimicrobial activities,and Fusarium graminearum inhibition was up to 90.28%.Then the antimicrobial activities of fermentation broth from four strains were detected by filtration with microporous filter membrane and high temperature steamed sterilization.It was found that the antimicrobial activities of the fermentation broth treated with the two ways were nealy same.3.Combined morphological and molecular identifications of endophytes with significant antimicrobial activityshowed that the dominant strains BN3,BN7,BN14 and BJF10 were Bacillus subtilis,Bacillus megaterium,Zopfiella sp.,and Neodeightonia subglobosa,respectively.4.Combined with plate qualitative and quantification of endogenous fermentation broth,endophytic fungi with broad antimicrobial spectrum were testedfor dissolving phosphorus and potassium,and the secretion of auxin(IAA)which could promote plant growth.It was found that only strain BN3 and BN7 had the ability to dissolve phosphorus.The effect of strain BN14 for potassium removal was the best,which was 38.39 mg/L.The strain BN7 produced an IAA concentration of164.39 mg/L,which was approximately 3 times that of the control standard.5.Cellulose degradation and antioxidant function were detected using endophytes with antimicrobial and growth promoting effects.The cellulase activity was reflected by detecting carboxymethyl cellulose activity and filter paper enzyme activity.DPPH radical scavenging was used to quantitatively detect the antioxidant capacity of the endophytic broth.It was showed that the enzyme activity of strain BN3 was the best.CMCase reached a maximum of 150.37 U/mL after 4 days cultivation,and FPase reached a maximum of 88.33 U/mL after 3 days cultivation,and the scavenging rate of DPPH free radical was the closest to that of the control group Vc.In summary,Endophytic strain BN3 and strain BN7 with excellent functions were obtained in this study.It laid the foundation for for the future development of biological agents and other products.