• The Plant Pathology Journal
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• v.24 no.1
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• pp.52-57
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• 2008

Twenty isolates of Bacillus spp. obtained from livestock manure composts and cotton-waste composts were tested for in vitro antagonistic effects against soilborne plant pathogenic fungi, Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani AG-4, and Sclerotinia sclerotiorum. Seven isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of F. oxysporum tested. The bacterial isolate RM43 was the most effective to inhibit the mycelial growth of the fungal isolates. Twelve isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of P. capsici tested. The bacterial isolates M34 and M47 were very effective to inhibit the mycelial growth of the fungal isolates. Thirteen isolates of Bacillus spp. had antagonistic effects on mycelial growth of all the isolates of R. solani AG-4 tested. The bacterial isolates M27 and M75 were very effective to inhibit the mycelial growth of the fungal isolates. Fourteen isolates of Bacillus sp. had antagonistic effects on mycelial growth of all the isolates of S. sclerotiorum tested. The bacterial isolates M49 and M75 were very effective to inhibit the mycelial growth of the fungal isolates. The antagonistic effects of most Bacillus spp. isolates against the isolates of the four fungi differed depending on the fungal species and the isolates of each fungus. The bacterial isolates M27 and M75 were the most effective to inhibit the mycelial growth of all four fungi.

• The Korean Journal of Mycology
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• v.13 no.1
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• pp.41-47
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• 1985

Eighteen plant residues were added to soil and the amended soil was inoculated with chlamydospores (5,000 cells/g soil) of Fusarium solani causing root rot of ginseng in soil to test the effects of amendment using pea (Pisium sativa L.) as an index plant. Distributional conditions of microogranisms in soil were compared with each other before and after dealing with soil amendment by plant debries. Infection rate by index plant's infectivity showed a higher degree in the treatment of wheat crushed than in control group, and followed by stalk of sweet potato, chinese cabbage, ginseng leaves and soybean pod. On the other hand, the de­creasing order of infection rate was root of garlic, welsh onion, cabbage leaf and stalk, green onion stalk, wheat straw and barley straw. In comparison with control group, the propagules of fungi increased in the treatment of ginseng leaves, soybean ground, wheat crushed, maize stalk, and chinese cabbage, but decreased in the root of garlic, cabbage, and barley straw. Population of total bacteria increased in the treatment of soybean ground, chinese cabbage, radish stalk, welsh onion, and wheat crushed, but decreased in barley straw, tobaco root, ginseng stalk, and wheat straw. The numbers of actinomycetes increased only in the treatment of soybean ground in a comparison with control and also decreased in the garlic stalk and tobaco root. The propagules of Fusarium spp increased in the treatment of chinese cabbage, welsh onion, radish stalk, wheat crushed, and sweet potato stalk, wheat crushed, and sweet potato stalk, but decreased in the treat­ment of wheat straw, ginseng leaves, and cabbage than control.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.1
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• pp.57-61
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• 2007

For developing an integrated eco-friendly package against root knot disease complex of mulberry caused by the association of Meloidogyne incognita with Fusarium solani and F. oxysporum causing serious loss in terms of leaf yield and quality during cultivation, twenty botanical extracts at 5, 10 & 20% concentrations were screened under in vitro conditions. Among the extracts, Allium sativum followed by Lasownia inermis were found to be effective at 20% concentration against both the virulent fungi and nematode. Both the extracts reduced the mycelial growth of virulent fungi to an extent of 76-100%, inhibited the hatching of nematode eggs by 80-90% and 76-85% larval mortality over the control. The other extracts were found either moderately or poorly effective in reducing the growth of fungi, hatching of nematode eggs and enhancing the mortality of larvae. The two effective botanical extracts, which rated as strong inhibitors against both nematode and virulent fungi, can be utilized in developing an integrated ecofriendly technology for better management of root knot disease complex in mulberry.

• Mycobiology
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• v.30 no.4
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• pp.233-239
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• 2002

The main aim of this study is to evaluate the efficiency of two biologically active compounds(Strom and F-760) in control of wheat root rot disease and its causal organisms. Fusarium graminearum, F. oxysporum, F. solani and Bipolaris sorokiniana were used as target organisms. In vitro, the two compounds showed fungicidal effect on all investigated pathogens resulted in suppression of radial growth and mycelial dry weight of them. Under greenhouse conditions, treatment of wheat grains with either Strom or F-760 before cultivation significantly reduced the percent of disease distribution as well as the mean disease rating of plants in both seedling and flowering stages. Fresh and dry weights of plants as well as water maintenance capacity were increased as the result of applying these compounds as seed dressing. Also data showed that the membrane stability of plants was injured as a result of infection with all investigated organisms, while this injury was alleviated when F-760 and Strom were applied. The $K^+$ efflux and the leakage of UV absorbing metabolites was stimulated with fungal infection. However, F-760 and Storm treatment partially retarded the stimulatory effect on leakage of $K^+$ and UV-absorbing metabolites of fungal infected plants. On the other side, the fungal infection had inhibitory effects on pigment fractions(chlorophyll a, b, and carotenoids) biosynthesis in wheat leaves. This retarding effect was partially or completely alleviated as the grains were treated with the applied compounds.

• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.268-277
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• 1998

The production of Korean ginseng, one of the most important medicinal root crops, is limited by many factors including soil sickness, root rots in fields as well as during storage prior to consumption. Although much research has been conducted on the diseases in field condition, little information is available on the control of postharvest roots rots. To obtain better management strategy of postharvest root rots in ginseng, biological control using antagonistic bacteria was attempted. Of 208 bacteria obtained form suppressive soil samples, 4 were selected based on the inhibitory effect on mycelial growth of two major causal fungi for postharvest root rots in ginseng, Botrytis cinerea and Fusarium solani. The culture filtrates of these bacterial antagonists greatly inhibited the conidial germination of both pathogenic fungi and produced abnormal morphology such as swollen germ tubes in F. solani and vacuolation of nongerminated conidia in B. cinerea. The population levels of bacterial antagonists on the ginseng roots were gradually increased up to 8 days of incubation. Postharvest root rots of ginseng caused by f. solani and B. cinerea were controlled in dipping tests in the ranges of 60∼80% by antagonistic Bacillus spp. obtained from suppressive soil. These results suggest that biological control using these antagonistic bacteria would be an alternative strategy to control postharvest root rots in ginseng.

• Journal of Ecology and Environment
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• v.46 no.2
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• pp.136-143
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• 2022

Background: In northern Thailand, the longan flower is the principal nectar source for honey production. Microorganisms play a critical function in the agricultural ecology. The morphological characteristics of fungal species found in longan pollen were studied. Aspergillus spp. were found to be invertase-producing strains and were employed in the longan syrup production process. The purpose of this study was to evaluate the effects of invertase-added longan syrup on the adult honey bee population numbers that were fed by this syrup for 16 weeks. Results: Different fungal species were found in longan pollen samples. Aspergillus was the main genus, with three predominant sections: Nigri, Flavi, and Terrei. Other isolated species were Trichoderma spp., Rhizopus spp., Neurospora spp., Chaetomium spp., Fusarium spp. and Penicillium spp. However, Aspergillus spp. is the only fungal species that produces the enzyme invertase. The invertase-producing strains belonging to the Aspergillus section Nigri were found to be A. niger LP5 with an optimum activity at pH 6.0 and 60℃. When A. niger LP5 invertase was used for longan syrup processing, the highest levels of glucose (3.45%) and fructose (2.08%) were found in invertase added longan syrup (C), while fresh (A) and boiled longan syrup (B) had lower contents of both sugars. The sucrose content was detected in (A) at 4.25%, while (B) and (C) were at 4.02% and 3.08%, respectively. An appropriate amount of sugar to feed and maintain the honey bee population was considered. The data showed no statistically significant differences between the two selected forms of longan syrup compared to the sugar syrup examined by the adult honey bee population. Conclusions: The main species of isolated fungi from longan pollen were Aspergillus spp. The discovery of an invertase-producing strain of A. niger LP5 has enabled its application for enzyme utilization in the invert sugar preparation process. The adult worker bee populations fed by longan syrup from both boiled and invertase-added sources showed an increasing trend. Artificial syrup made from longan fruit to feed honey bees when natural food sources are limited can be applied.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.305-309
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• 2002

Raw soybean sprouts were tested for contamination with the following bacteria which have potential for pathogenesis or food spoilage : Salmonella spp., Escherichia coli O157:H7, Yersinia enterocolitica, Vibrio parahae-molyticus, Aeromonas hydrophila, Plesidomonas shigeloides, Pseudomonas aeruginosa, Staphylococcus aureus, Lis-teria monocytogenes, Bacillus cereus, Clostridium perfringens, Campylobacter jejuni, Erwinia spp., and Fusarium spp. Three of the above strains were isolated from the sprouts, and identified by morphological and biochemical methods including an API kit and ATB automated identification system. The isolate cultured in Cereus selective agar, a selective medium, was a Gram-positive, rod shaped, anaerobic spore former. The biochemical and culture tests revealed the following characteristics: catalase-positive, no growth on Simmon's citrate, NO₂ production and requirement of arginine for growth; the ATB automated identification system gave 99.8 % agreement for the identification of Bacillus cereus to the species level. The isolate cultured in Macconkey agar selective medium was Gram-negative, rod shaped and a gas former; the ATB-system gave 99.9% agreement for the identification of Aeromonas hydrophila to the species level. The isolate found in Pseudomonas isolation agar was Gram-negative, rod shaped, cytochrome oxidase-positive, a reducer of nitrates to nitrogen, and pyocyanin producer; the ATB-system gave 99.9 % agreement for the identification of Pseudomonas aeruginosa to the species level. These results indicate that the three bacteria species present in the soybean sprouts were Bacillus cereus, Aero-monas hydrophila, and Pseudomonas aeruginosa. Salmonella spp., Escherichia coli O157:H7, and Yersinia enter-ocolitica, which are associated with serious disease in humans, were not isolated from soybean sprouts examined in this study.

• Research in Plant Disease
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• v.12 no.3
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• pp.267-271
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• 2006

Botrytis cinerea Pers. was found to be highly virulent to the grapevine plant, especially in greenhouse condition. Pseudomonas species play key roles for the biocontrol of many plant diseases especially in soil. Of the 83 isolates of Pseudomonas spp., a bacterial strain P84, isolated from tomato rhizosphere, was shown to suppress a wide range of phytopathogenic fungi in vitro. The isolate was identified as Pseudomonas putida on the basis of its bacteriological and genetic characteristics. The P. putida P84 strain carry the phlD gene for 2,4-diacetylphloroglucinol biosynthesis and may produce the antibiotics as an antagonistic mechanism involved in biocontrol. The antagonistic activity of the bacterium has a promising implication for its use as a biocontrol agent to control grapevine gray mold.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.49-49
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• 2014

In order to find indigenous beneficial fungal species from crop field soils of Nigeria, 23 soil samples were collected from various places of Nigeria in June, 2013 and fungi were isolated through serial dilution technique. Isolated fungi were purified and differentiated according to their morphological and microscopic characteristics. In total, 38 different representative isolates were recovered and the genomic DNA of each isolates was extracted using QIAGEN$^{(R)}$ Plasmid Mini Kit (QIAGEN Sciences, USA) and the identification of fungi was carried out by sequence analysis of internal transcribed spacer (ITS) region of the 18S ribosomal DNA (18S rDNA). Recovered isolates belonged to 9 fungal genera comprising Fusarium, Aspergillus, Chaetomium, Coniothyrium, Dipodascaceae, Myrothecium, Neosartorya, Penicillium and Trichoderma. Aspergillus spp., Penicillium spp. and Trichoderma spp. were the most dominant taxa in this study. The antagonistic potentiality of species belonged to Trichoderma against 10 phytopathogenic fungi (F. oxysporum, C. gloesporoides, P. cytrophthora, A. alternata, A. solani, S. rolfsii, F. solani, R. solani, S. sclerotiorum and P. nicotiana) was assessed in vitro using dual culture assay. The dual culture assay results showed varied degree of antagonism against the tested phytopathogens. The potential Trichoderma spp. will be further evaluated for their antagonistic and plant growth promotion potentiality under in vivo conditions.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.623-634
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• 2019

Little known the connections between soybeans mitogen-activated protein kinase (MAPK) gene expression and the rhizomicrobiome upon invasion of the root pathogen Fusarium oxysporum. To address this lack of knowledge, we assessed the rhizomicrobiome and root transcriptome sequencing of wild and cultivated soybean during the invasion of F. oxysporum. Results indicated F. oxysporum infection enriched Bradyrhizobium spp. and Glomus spp. and induced the expression of more MAPKs in the wild soybean than cultivated soybean. MAPK gene expression was positively correlated with Pseudomonadaceae but negatively correlated with Sphingomonadaceae and Glomeraceae in both cultivated and wild soybean. Specifically, correlation profiles revealed that Pseudomonadaceae was especially correlated with the induced expression of GmMAKKK13-2 (Glyma.14G195300) and GmMAPK3-2 (Glyma.12G073000) in wild and cultivated soybean during F. oxysporum invasion. Main fungal group Glomeraceae was positively correlated with GmMAPKKK14-1 (Glyma.18G060900) and negatively correlated with GmRaf6-4 (Glyma.02G215300) in the wild soybean response to pathogen infection; while there were positive correlations between Hypocreaceae and GmMAPK3-2 (Glyma.12G073000) and between Glomeraceae and GmRaf49-3 (Glyma.06G055300) in the wild soybean response, these correlations were strongly negative in the response of cultivated soybean to F. oxysporum. Taken together, MAPKs correlated with different rhizomicrobiomes indicating the host plant modulated by the host self-immune systems in response to F. oxysporum.