ABSTRACT
A serious leaf disease caused by Colletotrichum dematium was found during the cultivationof Sarcandra glabra in Jingxi, Rong’an, and Donglan Counties in Guangxi Province, whichinflicted huge losses to plant productivity. Biological control gradually became an effectivecontrol method for plant pathogens. Many studies showed that the application of actinomycetesin biological control has been effective. Therefore, it may be of great significance tostudy the application of actinomycetes on controlling the diseases caused by S. glabra.Strains of antifungal actinomycetes capable of inhibiting C. dematium were identified, isolatedand screened from healthy plants tissues and the rhizospheres in soils containing S.glabra. In this study, 15 actinomycetes strains were isolated and among these, strains JT-2F,DT-3F, and JJ-3F, appeared to show antagonistic effects against anthracnose of S. glabra.The strains JT-2F and DT-3F were isolated from soil, while JJ-3F was isolated from plantstems. The antagonism rate of strain JT-2F was 86.75%, which was the highest value amongthe three strains. Additionally, the JT-2F strain also had the strongest antagonistic activitywhen the antagonistic activities were tested against seven plant pathogens. Strain JT-2F isable to produce proteases and cellulase to degrade the protein and cellulose componentsof cell walls of C. dematium, respectively. This results in mycelia damage which leads toinhibition of the growth of C. dematium. Strain JT-2F was identified as Streptomyces tsukiyonensisbased on morphological traits and 16S rDNA sequence analysis.
ABSTRACT
A serious leaf disease caused by Colletotrichum dematium was found during the cultivationof Sarcandra glabra in Jingxi, Rong’an, and Donglan Counties in Guangxi Province, whichinflicted huge losses to plant productivity. Biological control gradually became an effectivecontrol method for plant pathogens. Many studies showed that the application of actinomycetesin biological control has been effective. Therefore, it may be of great significance tostudy the application of actinomycetes on controlling the diseases caused by S. glabra.Strains of antifungal actinomycetes capable of inhibiting C. dematium were identified, isolatedand screened from healthy plants tissues and the rhizospheres in soils containing S.glabra. In this study, 15 actinomycetes strains were isolated and among these, strains JT-2F,DT-3F, and JJ-3F, appeared to show antagonistic effects against anthracnose of S. glabra.The strains JT-2F and DT-3F were isolated from soil, while JJ-3F was isolated from plantstems. The antagonism rate of strain JT-2F was 86.75%, which was the highest value amongthe three strains. Additionally, the JT-2F strain also had the strongest antagonistic activitywhen the antagonistic activities were tested against seven plant pathogens. Strain JT-2F isable to produce proteases and cellulase to degrade the protein and cellulose componentsof cell walls of C. dematium, respectively. This results in mycelia damage which leads toinhibition of the growth of C. dematium. Strain JT-2F was identified as Streptomyces tsukiyonensisbased on morphological traits and 16S rDNA sequence analysis.
ABSTRACT
Objective The tissue culture of the stem apex of Knoxia valerianoides was done to research the optimum culture medium for test-tube seedlings for large-scale planting.Methods The stem apex of wild K.valerianoides was used as the explants and cultivated in different culture media separately to induce fascicled-bud,root,and plantlet regeneration.Results The cultural medium MS+BA 2.0 mg/L+NAA 0.1 mg/L was suitable for the sub-multiplication of fascicled bud and the medium 1/2MS+NAA 1.0 mg/L for root inducement and the plantlet regeneration.The transplantation survival rate of the plantlet regeneration was 70%.Conclusion The tissue culture of K.valerianoides could be used to produce test-tube seedlings for large-scale planting.