Dual biocontrol of both insects and plant pathogens has been reported for certain fungal entomopathogens, including Beauveria bassiana and Lecanicillum spp. In this study, we demonstrate, for the first time, the dual biocontrol potential of two fungal isolates identified by morphological and phylogenetic analyses as Isaria javanica. Both these isolates caused mortality in the greater wax moth, and hence can be considered entomopathogens. Spores of the isolates were also pathogenic to nymphs of the green peach aphid (Myzus persicae), with an LC₅₀ value of 10⁷ spores/mL 4 days after inoculation and an LT₅₀ of 4.2 days with a dose of 10⁸ spores/mL. In vitro antifungal assays also demonstrated a strong inhibitory effect on the growth of two fungi that are pathogenic to peppers, Colletotrichum gloeosporioides and Phytophthora capsici. These results indicate that I. javanica isolates could be used as novel biocontrol agents for the simultaneous control of aphids and fungal diseases, such as anthracnose and Phytophthora blight, in an integrated pest management framework for red pepper.
Aphids* ; Beauveria ; Capsicum ; Colletotrichum ; Fungi* ; Hemiptera ; In Vitro Techniques ; Insects ; Mortality ; Moths ; Nymph ; Pest Control ; Phytophthora ; Plants* ; Prunus persica ; Spores

Black rot disease in orchids is caused by the water mold Phytophthora palmivora. To gain better biocontrol performance, several factors affecting growth and antifungal substance production by Pseudomonas aeruginosa RS1 were verified. These factors include type and pH of media, temperature, and time for antifungal production. The results showed that the best conditions for P. aeruginosa RS1 to produce the active compounds was cultivating the bacteria in Luria-Bertani medium at pH 7.0 for 21 h at 37 °C. The culture filtrate was subjected to stepwise ammonium sulfate precipitation. The precipitated proteins from the 40% to 80% fraction showed antifungal activity and were further purified by column chromatography. The eluted proteins from fractions 9–10 and 33–34 had the highest antifungal activity at about 75% and 82% inhibition, respectively. SDS-PAGE revealed that the 9–10 fraction contained mixed proteins with molecular weights of 54 kDa, 32 kDa, and 20 kDa, while the 33–34 fraction contained mixed proteins with molecular weights of 40 kDa, 32 kDa, and 29 kDa. Each band of the proteins was analyzed by LC/MS to identify the protein. The result from Spectrum Modeler indicated that these proteins were closed similarly to three groups of the following proteins; catalase, chitin binding protein, and protease. Morphological study under scanning electron microscopy demonstrated that the partially purified proteins from P. aeruginosa RS1 caused abnormal growth and hypha elongation in P. palmivora. The bacteria and/or these proteins may be useful for controlling black rot disease caused by P. palmivora in orchid orchards.
Ammonium Sulfate ; Bacteria ; Carrier Proteins ; Catalase ; Chitin ; Chromatography ; Electrophoresis, Polyacrylamide Gel ; Fungi* ; Hydrogen-Ion Concentration ; Hyphae ; Microscopy, Electron, Scanning ; Molecular Weight ; Phytophthora* ; Pseudomonas aeruginosa* ; Pseudomonas* ; Water

Phytophthora diseases have become a major impediment in the citrus production in Thailand. In this study, an isolate of Phytophthora denominated as PHY02 was proven to be causal pathogen of root rot of Pomelo (Citrus maxima) in Thailand. The isolate PHY02 was morphologically characterized and identified as Phytophthora palmivora based on molecular analysis of an internal transcribed spacer rDNA sequence. This work also presents in vitro evaluations of the capacities of Chaetomium spp. to control the P. palmivora PHY02. As antagonists, Chaetomium globosum CG05, Chaetomium cupreum CC3003, Chaetomium lucknowense CL01 inhibited 50~61% mycelial growth, degraded mycelia and reduced 92~99% sporangial production of P. palmivora PHY02 in bi-culture test after 30 days. Fungal metabolites from Chaetomium spp. were tested against PHY02. Results showed that, methanol extract of C. globosum CG05 expressed strongest inhibitory effects on mycelial growth and sporangium formation of P. palmivora PHY02 with effective dose ED50 values of 26.5 microg/mL and 2.3 microg/mL, respectively. It is interesting that C. lucknowense is reported for the first time as an effective antagonist against a species of Phytophthora.
Chaetomium* ; Citrus ; DNA, Ribosomal ; Methanol ; Phytophthora* ; Sporangia ; Thailand

Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 microg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.
Asia, Southeastern ; Biological Control Agents* ; Chaetomium* ; Citrus* ; Complex Mixtures ; DNA, Ribosomal ; Hyphae ; Methanol ; Oomycetes ; Phytophthora* ; Plants ; Seedlings ; Sequence Analysis ; Spores ; Thailand ; Tobacco*

Based on previous results of 16S rDNA sequence homologuous and results of physic-biochemical indexes and morphological characteristics in the present work, bacterial strain ge15 isolated from roots of ginseng plants was identified as Stenotrophomonas rhizophila. Confronting incubation results showed that, strain ge15 inhibited the growth of Alternaria panax, Phytophthora cactorum, and Cylindrocapon destructans significantly, and the width of inhibition zone was 13.3, 24.0, 12.0 mm, respectively. Further results showed that the emergence rate and seedling survive rate of ge15 treatment was significantly higher than those of the control, and which was similar to pesticide carbendazol treatment. The ge15 strain has good application potential in ginseng diseases control without contamination.
Alternaria ; growth & development ; physiology ; Antibiosis ; Biological Control Agents ; Hypocreales ; growth & development ; physiology ; Panax ; growth & development ; microbiology ; Phytophthora ; growth & development ; physiology ; Plant Diseases ; microbiology ; Plant Roots ; growth & development ; microbiology ; Seedlings ; growth & development ; microbiology ; Stenotrophomonas ; classification ; cytology ; isolation & purification ; physiology

Sequence characterized amplified region (SCAR) markers are one of the most effective and accurate tools for microbial identification. In this study, we applied SCAR markers for the rapid and accurate detection of Phytophthora katsurae, the casual agent of chestnut ink disease in Korea. In this study, we developed seven SCAR markers specific to P. katsurae using random amplified polymorphic DNA (RAPD), and assessed the potential of the SCAR markers to serve as tools for identifying P. katsurae. Seven primer pairs (SOPC 1F/SOPC 1R, SOPC 1-1F/SOPC 1-1R, SOPC 3F/SOPC 3R, SOPC 4F/SOPC 4R, SOPC 4F/SOPC 4-1R, SOPD 9F/SOPD 9R, and SOPD 10F/SOPD 10R) from a sequence derived from RAPD fragments were designed for the analysis of the SCAR markers. To evaluate the specificity and sensitivity of the SCAR markers, the genomic DNA of P. katsurae was serially diluted 10-fold to final concentrations from 1 mg/mL to 1 pg/mL. The limit of detection using the SCAR markers ranged from 100 microg/mL to 100 ng/mL. To identify the limit for detecting P. katsurae zoospores, each suspension of zoospores was serially diluted 10-fold to final concentrations from 10 x 10(5) to 10 x 10(1) zoospores/mL, and then extracted. The limit of detection by SCAR markers was approximately 10 x 10(1) zoospores/mL. PCR detection with SCAR markers was specific for P. katsurae, and did not produce any P. katsurae-specific PCR amplicons from 16 other Phytophthora species used as controls. This study shows that SCAR markers are a useful tool for the rapid and effective detection of P. katsurae.
Cicatrix ; DNA ; Ink ; Korea ; Limit of Detection ; Phosphatidylcholines ; Phytophthora ; Polymerase Chain Reaction ; Sensitivity and Specificity

OBJECTIVETo observe the effects of a biotic elicitor fungal hyphae extract, an abiotic elicitor methyl jasmonate and their synergistic action on the accumulation of phenolic acids and tanshinones in Salvia miltiorrhiza hairy root.

METHODDifferent elicitors were added to S. miltiorrhiza hairy root, which was subcultured for 21 days, the dry weight and contents of phenolic acids and tanshinones were determined at different harvest-time.

RESULTS. miltiorrhiza hairy root growth was significantly inhibited by all three treatments and the accumulation of cryptotanshinone and dihydrotanshinone were promoted by each elicition. As for the accumulation of phenolic acids, there were differences between fungal elicitor and methyl jasmonate treatments, they were promoted by methyl jasmonate while inhibited in a certain extent by fungal hyphae extract.

CONCLUSIONFungal elicitor, methyl jasmonate and their synergistic action have significant influence on accumulation of components in S. miltiorrhiza hairy root, and the effect varies between phenolic acids and tanshinones. There is no correlation between production of water-soluble ingredients and fat-soluble components on the whole under three different treatments.

Acetates ; pharmacology ; Cyclopentanes ; pharmacology ; Diterpenes, Abietane ; metabolism ; Fungal Proteins ; metabolism ; pharmacology ; Hydroxybenzoates ; metabolism ; Membrane Glycoproteins ; metabolism ; pharmacology ; Oxylipins ; pharmacology ; Phytophthora ; chemistry ; metabolism ; Plant Extracts ; metabolism ; Plant Roots ; drug effects ; growth & development ; metabolism ; microbiology ; Salvia miltiorrhiza ; drug effects ; growth & development ; metabolism ; microbiology

Antagonistic mechanisms of Trichoderma viride M3, Tv04-2, and T. harzianum ThB, were studied against Phytophthora nicotianae, the pathogen of stem blight disease on Schizonepeta tenuifolia by dual-culture, hydrolase activity, volatile and nonvolatile substances. Results indicated that competitive, mycoparasitism and antagonism were the antagonistic mechanisms of three Trichoderma spp. against P. nicotianae. Hydrolase activity showed that M3 was the highest for beta-1, 3-glucanases activity while ThB was the highest for proteases activity among the three T. strains, and they could produce volatile and non-volatile substances, also.
Fungal Proteins ; metabolism ; Hydrolases ; metabolism ; Lamiaceae ; parasitology ; Peptide Hydrolases ; metabolism ; Pest Control, Biological ; Phytophthora ; microbiology ; physiology ; Plant Diseases ; parasitology ; Trichoderma ; enzymology ; physiology

OBJECTIVETo screen the Trichodenna spp. for strong antagonist against ginseng root pathogens.

METHODThe biological characters of ten Trichoderma strains were compared by culturing on different media. And their antagonistic activity against Phytophthora cactorum, Cylindrocarpon destructans and Rhizoctonia solani were measured on PDA.

RESULT AND CONCLUSIONTv04-2 and Th3080 showed a good growth on soil solution medium and PDA, and also showed high inhibitory efficacy to the three pathogens. The two Trichoderma strains showed different growth rate under light conditions and pH. Trichoderma strains were sensitive to most fungicides used in ginseng root disease controlling, however Tv04-2 was not sensitive to the fungicide Junchong Jueba.

Ascomycota ; pathogenicity ; Hydrogen-Ion Concentration ; Light ; Panax ; microbiology ; Phytophthora ; pathogenicity ; Plant Diseases ; microbiology ; Plant Roots ; microbiology ; Plants, Medicinal ; microbiology ; Rhizoctonia ; pathogenicity ; Soil Microbiology ; Trichoderma ; growth & development ; isolation & purification ; physiology

Soil cyanobacteria isolated from the rice paddy fields of 10 different locations across Korea were evaluated by agar plate diffusion test for antifungal activity. Aqueous, petroleum ether, and methanol extracts from one hundred and forty two cyanobacterial strains belonging to the 14 genera were examined for antifungal properties against seven phytopathogenic fungi causing diseases in hot pepper (Capsicum annuum L). Of total cyanobacteria, nine cyanobacteria (6.34%) exhibited antifungal effects. The nine cyanobacteria selected with positive antifungal activities were two species of Oscillatoria, two of Anabaena, three of Nostoc, one of Nodularia, and one of Calothrix. Alternaria alternata and Botrytis cinerea were inhibited by nine and eight species of cyanobacteria, respectively. Rhizopus stolonifer was suppressed by only methanol extract of Nostoc commune FK-103. In particular, Nostoc commune FK-103 and Oscillatoria tenuis FK-109 showed strong antifungal activities against Phytophthora capsici. Their antifungal activity at the late exponential growth phase is related to the growth temperature and not associated with the growth parameters such as cell biomass and chlorophyll-alpha concentration. The high inhibition levels of antibiotics were 22.5 and 31.8 mm for N. commune FK-103 and O. tenuis FK-109, respectively. The optimal temperature for antibiotic productivity was 35degrees C.
Agar ; Alternaria ; Anabaena ; Anti-Bacterial Agents ; Biomass ; Botrytis ; Cyanobacteria* ; Diffusion ; Efficiency ; Ether ; Fungi* ; Korea ; Mass Screening* ; Methanol ; Nodularia ; Nostoc ; Nostoc commune ; Oscillatoria ; Petroleum ; Phytophthora ; Plants* ; Rhizopus ; Soil*