Isolation And Antagonistic Activity Of Antagonistic Actinomycetes In Rhizosphere Microorganisms Of Pepper

1.The strains were separated from the soil of capsicum rhizosphere collected from Guizhou province by plate dilution method.The 87 strain were found.By the methods of spread plate to determination of antibacterial activity of the isolates were tested against Erwinia carotorora,Xanthomonas axonopodis pv.citri,Ralstonia solanacearum.The results showed that the total of 40 strains against more than one bacterial pathogens show some different degree of antimicrobial activity;By the method of plate confrontation to determination of antifungal activity of the isolates were tested against Thanatephorus cucumeris,Glomerella cingulata,Sclerotinia sclerotiorum,Cytospora mandshurica,Verticillium dahliae,Phytophthora infestans.The results showed that the total of 30 strains against more than one fungus pathogens show antifungal activity.The antifungal activity of the strains were screened by inhibiting the growth rate,six fungus pathogens as indicator fungus were Thanatephorus cucumeris,Glomerella cingulata,Sclerotinia sclerotiorum,Cytospora mandshurica,Verticillium dahliae,Phytophthora infestans.The results showed that strain WKFF21,WKFF31,WKFF33,WKFF34,WKFF40,WKFF54,WKFF67 and WKFF86 had an inhibition of 60% above against Verticillium dahliae,strain WKFS4 had an inhibition of 74.14% against Sclerotinia sclerotiorum.The algae-lysing activity of the strains were studied by means of the method of dissolving algae,the results showed that there were three strains showed algae-lysing activity.There were WKFF31,WKFF34 and WKFF37.2.Molecular biology was identified for isolates with good antagonistic activity,the results showed that,the strains belong to 3 families,5 classes,7 orders,8 families,9 genera.3.The candidate strains WKFF34 and WKFS4 were identified by morphological characteristics,culture characteristics,physiological and biochemical characteristics and molecular biology.The results showed that,WKFF34 and WKFS4 belonged to actinomycetes,actinomycetes,actinomycetes,Streptomyces,Streptomyces,Streptomyces.WKFF34 was identified as Streptomyces cyaneofuscatus and WKFS4 was identified as Streptomyces violascens,respectively.4.The antibacterial spectrum and stability of fermentation broth of WKFF34 and WKFS4 were studied.the results showed that,WKFF34 and WKFS4 had the characteristics of broad antibacterial spectrum,showed different antibacterial activity against Thanatephorus cucumeris,Glomerella cingulata,Sclerotinia sclerotiorum,Cytospora mandshurica,Verticillium dahliae,Gibberlla zeae,Phytophthora infestans,Phytophthora capsici,Botrytis cinerea.The fermentation broth of strain WKFF34 had an inhibition of 70%、79.48%、80.43% against Thanatephorus cucumeris,Glomerella cingulata,Sclerotinia sclerotiorum,respectively;the fermentation broth of strain WKFS4 had an inhibition of 75.71%、74.39%、83.8%、78.17% against Thanatephorus cucumeris,Glomerella cingulata,Sclerotinia sclerotiorum,Verticillium dahliae,respectively.Strain WKFF34 on the temperature and UV instability,pH value is relatively stable;strain WKFS4 on the pH value is relatively stable,the temperature and UV instability;strain WKFS4 on the pH value is relatively stable,the temperature and UV instability.5.Study on the actinomycetes of algae-lysing strain WKFF34,the results showed that the algae-producing strain WKFF34 was able to indirectly inhibit the normal growth of Microcystis aeruginosa by releasing extracellular algae-lysing actives,and the extracellular algae-lysing activity could still maintain strong algicidal activity after sterilization at 121 ℃ for 30 min,stability.