1.Evaluation of the biocontrol potential of endophytic bacteria isolated from Coffea liberica (w. Bull ex hiern) against brown eyespot-causing fungal phytopathogen
Gary Antonio C. Lirio ; Anna Beatriz A. Suavengco ; Kathleen Chloie C. Antonio ; John Eric P. Aggarao ; Janeth G. Mamansag
Malaysian Journal of Microbiology 2020;16(6):477-490
Aims:
The study aims to investigate the potential of the endophytic bacteria as an alternative to control the devastating
brown eyespot disease caused by Cercospora sp. in coffee plants. The fungal phytopathogen causes severe leaf fall
and berry damages resulting in serious yield losses in coffee farms in the Philippines and worldwide. Currently, the
management of this fungal infection relies heavily on synthetic fungicides, which may be of major environmental
concern.
Methodology and results:
Endophytic bacteria were isolated from the intercellular tissues of Coffea liberica leaves by
surface sterilization, maceration, dilution technique, plating on trypticase soy agar and colony characterization.
Fourteen isolated endophytic bacteria were screened for their ability to inhibit the mycelial growth of Cercospora sp.
through modified dual culture assay. Isolates HCC10-3SC3, HCC10-3SC2, HCC10-1SC1, ICC10-3SC1, and ICC10-1SC1
yielded the highest percent inhibition of radial growth (PIRG) with 59.56%, 60.92%, 60.96%, 64.36%, and 67.06%
respectively and are statistically significant (p<0.05) compared to the antibiotic control nystatin. The top five performing
endophytic bacteria were subjected to hydrolytic enzyme production assays and found to exhibit amylolytic, lipolytic,
proteolytic, chitinolytic, and cellulolytic activities. Based on the morphological and molecular identification by the 16S
rRNA sequence analysis, isolates showed the similarity with Staphylococcus cohnii, Bacillus siamensis,
Staphylococcus hominis, and Kosakonia cowanii found in GENBANK.
Conclusion, significance and impact of study
The study revealed the biological control potential of endophytic
bacteria agents against the brown eyespot-causing fungus in coffee.
Endophytes--pathogenicity
2.Isolation and identification of endophytic fungi from Chelidonium majus and their antifungal activity.
Ting HUANG ; Wei XIE ; Xiao-Dong LIU ; Kai-Xun TANG ; Rui YANG
China Journal of Chinese Materia Medica 2019;44(3):460-464
In order to find new source of antifungal agents, eleven cultivable endophytic fungi were isolated from the roots,stems and leaves of Chelidonium majus by traditional method. Seven of them were identified as Colletotrichum(L1, L2, L3, S1, S3, S4, S5), and three of them were identified as Fusarium(R1,R2,R3) by morphological features and molecular biological technology. The antifungal activity test showed that all the tested fungi displayed some inhibitory activity against five common plant pathogens(C. gloeosporioides, Curvularia lunata, Pyricularia oryza, Alternaria alternate and A. brassicae), and their inhibition rate of some test items were over 60%. Among them, R1, S2, S3 and S4 were more potent than others. This study enriches the understanding of endophytes from Ch. majus and provides a basis for the study of new microbial fungicides.
Alternaria
;
pathogenicity
;
Antibiosis
;
Ascomycota
;
pathogenicity
;
Chelidonium
;
microbiology
;
Colletotrichum
;
chemistry
;
isolation & purification
;
Endophytes
;
chemistry
;
isolation & purification
;
Fusarium
;
chemistry
;
isolation & purification
3.Isolation,screening and identification of endophytic fungi and detection of its antifungal effects against Alternaria panax.
Chun-Yuan ZHOU ; Xiang-Min PIAO ; Mei-Xia YAN ; Ying-Ping WANG
China Journal of Chinese Materia Medica 2019;44(2):274-277
To obtain biocontrol fungus for Alternaria panax,the antifungal effects of one strain of endophytic fungi isolated from leaves of healthy ginseng were screened and evaluated by using dual-culture method,and the taxonomic assignment of the screened strain was identified based on the morphological characters and ITS sequence analysis. The results of dual-culture showed that one of the endophytes marked as FS-01 had good antifungal effects and the inhibitory rates of FS-01 strain to A. panax was( 60. 21±0. 12) %.The hyphae junction of the both strains,A. panax dissolved,broke and winded,while the hyphae of FS-01 strain remained normal. The inhibitory rates of non-sterilized FS-01 strain fermentation liqud was( 13. 94±0. 21) %. Strain FS-01 identified as Chaetomium globosum.
Alternaria
;
pathogenicity
;
Antibiosis
;
Chaetomium
;
classification
;
isolation & purification
;
Endophytes
;
isolation & purification
;
Fungicides, Industrial
;
Panax
;
microbiology
;
Plant Diseases
;
prevention & control
4.Identification of endophytic bacteria BZJN1 and research on biological control of root rot of Atractylodes macrocephala.
Jing-Mao YOU ; Kun XIONG ; Sen MU ; Jie GUO ; Xiao-Liang GUO ; Yuan-Yuan DUAN ; Juan LI ; Fan CAO ; Zong-Cheng ZOU ; Hai TAN
China Journal of Chinese Materia Medica 2018;43(3):478-483
In this study, an endophytic bacteria strain BZJN1 was isolated from Atractylodes macrocephala, and identified as Bacillus subtilis by physiological and biochemical tests and molecular identification. Strain BZJN1 could inhibit the growth of mycelia of Ceratobasidium sp. significantly, and the inhibition rate was more than 70%. The mycelium growth deformity with bulge as spherical and partially exhaustible in apex or central with microscopic observation. The inhibitory rates under 3% and 6% concentrations of the cell free fermentation were 22.7% and 38.7% expectively. The field test proved that the control efficacy of treatment of 1×10⁸ cfu·mL⁻¹ is 75.27% and 72.37% after 10 and 20 days. All the treatments of strain BZJN1 was able to promote the growth of A. macrocephala, the treatment of 1×10⁸ cfu·mL⁻¹ could able to increase the yield to 14.1%.
Atractylodes
;
microbiology
;
Bacillus subtilis
;
physiology
;
Basidiomycota
;
pathogenicity
;
Biological Control Agents
;
Endophytes
;
classification
;
isolation & purification
;
Plant Diseases
;
microbiology
;
prevention & control