The effect of temperature (18°C - 30°C), water activity (0.85 - 1) and pH (4 - 9) was studied by dual culture technique on the antagonism of Bacillus amyloliquefaciens and Trichoderma harzianum to Colletotri...The effect of temperature (18°C - 30°C), water activity (0.85 - 1) and pH (4 - 9) was studied by dual culture technique on the antagonism of Bacillus amyloliquefaciens and Trichoderma harzianum to Colletotrichum acutatum, responsible of strawberry (Fragaria x ananassa (Weston) Duchesne ex Rozier) anthracnose. The antagonistic bacteria’s strains behave significantly and differently according to the parameters studied. These results reveal useful information about the applicability of their biocontrol in agricultural culture with the change of environmental factors.展开更多
Species of Trichoderma, Penicillium, Aspergillus and Mucor were found to dominate the rhizosphere of tea bushes in different regions of the Indian Himalayas. The Himachal Himalayas were dominated by Monilia humiscola ...Species of Trichoderma, Penicillium, Aspergillus and Mucor were found to dominate the rhizosphere of tea bushes in different regions of the Indian Himalayas. The Himachal Himalayas were dominated by Monilia humiscola (45.08%) and Mucor hiemalis (33.11%). In the Uttaranchal Himalayas, Aspergillus clavatum dominated the rhizosphere (54.01%), followed by A. flavous (20.07%). Although the fungal isolates require a mesophillic temperature (15 ℃ to 35 ℃), the tea rhizospheric isolates tolerate a wide range of temperatures (5 ℃ to 45 ℃). When tested for pH tolerance, these fungi showed a wide range (2.0 to 13.0) of pH tolerance under in vitro conditions. Seasonal variations also influenced the colony forming units (cfu) of the rhizospheric fungi, with the maximum forming in November and March, and the minimum in December^February. During this period, the populations of the fungi were found inversely proportional to the bacterial populations. In addition, the dominant bacteria in the tea rhizosphere, i.e., Bacillus subtilis and B. mycoides, showed antagonistic activity against fungal isolates by inhibiting the growth and causing structural abnormalities in mycelium. Tab 5, Ref展开更多
Through a modified agar well diffusion assay,antagonism of a novel chitinase-producing strain C3 against the phy- topathogenic fungi including Phoma wasabiae Yokogi,Cochlibolus Heterostrophus,Exserohilum Turcicum,Curu...Through a modified agar well diffusion assay,antagonism of a novel chitinase-producing strain C3 against the phy- topathogenic fungi including Phoma wasabiae Yokogi,Cochlibolus Heterostrophus,Exserohilum Turcicum,Curuvularia Lunata (Walk)Boed,Thantephorus cucumris,Fusarium graminearum was tested.The data showed that the crude extracts of strain C3 had stable antifungal activity in the range of pH 5.0 to pH 8.0.The active components were heat labile and sensitive to proteinase K.A series of experiments supported that the compound responsible for inhibitory aetivity appeared to be chitinase.The 16s rDNA analysis indicated that C3 was subject to genus Burkholderia.Phenotypic characterization of C3 was also consisted with the result of molecular identification.展开更多
[Objective] The paper was to identify strain HN-1 against banana wilt disease and to determine its antagonism. [Method] The strain HN-1 was ob- tained from the soil in fields heavily infected by Fusarium oxysporum f. ...[Objective] The paper was to identify strain HN-1 against banana wilt disease and to determine its antagonism. [Method] The strain HN-1 was ob- tained from the soil in fields heavily infected by Fusarium oxysporum f. sp. cubense （FOC）. Antagonism of the strain against F. oxysporum was tested via dual-cul- ture and inhibition test on spore germination. [Result] HN-1 effectively inhibited mycelial growth and spore germination of F. oxysporum, Strain HN-1 was identi- fied as BrevibaciUus brevis according to its characteristics in morphology, physiology and biochemistry and its 16S rDNA sequence. The strain showed high inhibition effect on 15 species of fungal pathogens in the dual-culture trials with fungal pathogens. [ Conclusion] The study provides theoretical basis for application of strain HN-1 in agricultural fields.展开更多
Variations in the radial growth rate of 24 isolates belonging to ten species of Trichoderma, three isolates of conifer pathogen Heterobasidion annosum s.s. and four isolates of H. parviporum were evaluated by incubati...Variations in the radial growth rate of 24 isolates belonging to ten species of Trichoderma, three isolates of conifer pathogen Heterobasidion annosum s.s. and four isolates of H. parviporum were evaluated by incubation on a solid malt extract medium at a temperature of 4℃, 15℃ and 21℃. Trichoderma antagonism against Heterobasidion was investigated in dual culture in vitro. The slowest rate of growth was referable to all seven strains of Heterobasidion spp. All Heterobasidion spp. strains were overgrown by 63% of Trichoderma spp. strains after two weeks at 21℃ and by 33% of strains at 15℃. 21% of Trichoderma strains did not grow and only four strains belonging to T. koningii, T. viride and T. viridescens demonstrated the ability to completely overgrow Heterobasidion spp. after two weeks incubation at 4℃. According to the antagonistic efficiency, Trichoderma strains were divided into five groups with an Euclidean distance of 25. The groups contained isolates from different species. It was suggested that selected psychrotrophic fast growing T. viride, T. koningii and T. viridescens strains could be examined in different substrate conditions as suitable antagonist agents for the control of H. annosum and H. parviporum.展开更多
Synergism and antagonism of cadmium (Cd), copper (Cu) and selenium (Se) to biological toxicities in red soil, yellow brown soil and black soil were evaluated by MICROTOX method. The relation between forms of the teste...Synergism and antagonism of cadmium (Cd), copper (Cu) and selenium (Se) to biological toxicities in red soil, yellow brown soil and black soil were evaluated by MICROTOX method. The relation between forms of the tested metals in soil and the synergism or antagonism between them was also studied.Results showed that owing to the difference of soil chemical properties, toxicity of these metals in soils was different. In red soil with acid reaction and low in cation exchange capacity, antagonism occurred significantly between metals when they coexisted at high concentrations, while synergism occurred only under low concentrations. It is indicated that in red soil, toxicity of metals affected by synergism or antagonism depends on concentration of the metals present. For yellow brown soil and black soil with larger cation exchange capacity and lower exchangeable aluminium (A1), no toxicity of metals was observed even if metals were added to soil in high concentrations. Synergism and antagonism between Cd, Cu and Se were controlled by the forms of metals present. The amount of water-soluble metals was the most important factor in determining synergism and antagonism.In this paper, comparisons of synergism and antagonism between metals in soils and in water solutions were made. There occurred the synergism of metal toxicity in water solutions when the concentration of coexisting metals was high. This is just opposite to the case in soils.展开更多
The local isolates of Trichoderma spp. and Fusarium solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch’s postulate testing. The re...The local isolates of Trichoderma spp. and Fusarium solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch’s postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderma spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta.展开更多
The world military situation in 2016was complex,military strategies of major countries undergoing profound readjustment,contest in emerging fields increasing and a new round of populism cropping up worldwide which res...The world military situation in 2016was complex,military strategies of major countries undergoing profound readjustment,contest in emerging fields increasing and a new round of populism cropping up worldwide which resulted in'Black swan events'happening one after another,major-country contest and geopolitical conflicts piling up and local展开更多
A strain B34 against Thanatephorus cucumeris was screened from rice plants. Lab and field experiments showed that the control effects of this fungal strain were better than that of Jinggangmycin on PDA plate. Based on...A strain B34 against Thanatephorus cucumeris was screened from rice plants. Lab and field experiments showed that the control effects of this fungal strain were better than that of Jinggangmycin on PDA plate. Based on the chemical components of cell wall and physiological and biochemical characters of B34, the fungal was named as Pseudomonas aureofaciens. It was a new antagonistic strain against Thanatephorus cucumeris.展开更多
[ Objective] The aim of this study was to isolate the endophyte of three solanaceae fruits and vegetables such as tomato, pepper and eggplant, to screen and identify the bacterial wilt antagonistic bacteria. [ Methodl...[ Objective] The aim of this study was to isolate the endophyte of three solanaceae fruits and vegetables such as tomato, pepper and eggplant, to screen and identify the bacterial wilt antagonistic bacteria. [ Methodl According to the lapping liquid culture method, the endophyte of three plants was isolated by the selective medium and purified by the plate streaking method, so the purified enclophyte was screened by the hyphal pieces confront culture method. Furthermore, the screened antagonistic and endophyteic bacteria was identified and classified through culture characteristics of isolates and morphological features of thallus, Gram stain as well as physiological and biochemical reactions. [ Result] Fifty-three endophytic bacteria, fifty-three endophytic fungi and forty-four endophytic actinomycetes were separated from the endophyte of three plants. The screened fourteen endophytic bacteria with strong antagonistic effect on the bacterial wilt were classified to Bacillus, Escherichia, Klebsiella, Agromonas, Erwinia and Curto Bacterium respectively. Especially, Bacillus was the dominant species, which had the strongest antagonistic effect on the bacterial wilt. [ Conclusion] This study provides an effective way for biological control of the bacterial wilt in solanaceae.展开更多
文摘The effect of temperature (18°C - 30°C), water activity (0.85 - 1) and pH (4 - 9) was studied by dual culture technique on the antagonism of Bacillus amyloliquefaciens and Trichoderma harzianum to Colletotrichum acutatum, responsible of strawberry (Fragaria x ananassa (Weston) Duchesne ex Rozier) anthracnose. The antagonistic bacteria’s strains behave significantly and differently according to the parameters studied. These results reveal useful information about the applicability of their biocontrol in agricultural culture with the change of environmental factors.
文摘Species of Trichoderma, Penicillium, Aspergillus and Mucor were found to dominate the rhizosphere of tea bushes in different regions of the Indian Himalayas. The Himachal Himalayas were dominated by Monilia humiscola (45.08%) and Mucor hiemalis (33.11%). In the Uttaranchal Himalayas, Aspergillus clavatum dominated the rhizosphere (54.01%), followed by A. flavous (20.07%). Although the fungal isolates require a mesophillic temperature (15 ℃ to 35 ℃), the tea rhizospheric isolates tolerate a wide range of temperatures (5 ℃ to 45 ℃). When tested for pH tolerance, these fungi showed a wide range (2.0 to 13.0) of pH tolerance under in vitro conditions. Seasonal variations also influenced the colony forming units (cfu) of the rhizospheric fungi, with the maximum forming in November and March, and the minimum in December^February. During this period, the populations of the fungi were found inversely proportional to the bacterial populations. In addition, the dominant bacteria in the tea rhizosphere, i.e., Bacillus subtilis and B. mycoides, showed antagonistic activity against fungal isolates by inhibiting the growth and causing structural abnormalities in mycelium. Tab 5, Ref
文摘Through a modified agar well diffusion assay,antagonism of a novel chitinase-producing strain C3 against the phy- topathogenic fungi including Phoma wasabiae Yokogi,Cochlibolus Heterostrophus,Exserohilum Turcicum,Curuvularia Lunata (Walk)Boed,Thantephorus cucumris,Fusarium graminearum was tested.The data showed that the crude extracts of strain C3 had stable antifungal activity in the range of pH 5.0 to pH 8.0.The active components were heat labile and sensitive to proteinase K.A series of experiments supported that the compound responsible for inhibitory aetivity appeared to be chitinase.The 16s rDNA analysis indicated that C3 was subject to genus Burkholderia.Phenotypic characterization of C3 was also consisted with the result of molecular identification.
基金Supported by Special Funds for Construction of Modern Agricultural Technology System(nycytx-24)Fundamental Research Special Project for Central Public-interest Scientific Institutes(ITBB130502)
文摘[Objective] The paper was to identify strain HN-1 against banana wilt disease and to determine its antagonism. [Method] The strain HN-1 was ob- tained from the soil in fields heavily infected by Fusarium oxysporum f. sp. cubense （FOC）. Antagonism of the strain against F. oxysporum was tested via dual-cul- ture and inhibition test on spore germination. [Result] HN-1 effectively inhibited mycelial growth and spore germination of F. oxysporum, Strain HN-1 was identi- fied as BrevibaciUus brevis according to its characteristics in morphology, physiology and biochemistry and its 16S rDNA sequence. The strain showed high inhibition effect on 15 species of fungal pathogens in the dual-culture trials with fungal pathogens. [ Conclusion] The study provides theoretical basis for application of strain HN-1 in agricultural fields.
文摘Variations in the radial growth rate of 24 isolates belonging to ten species of Trichoderma, three isolates of conifer pathogen Heterobasidion annosum s.s. and four isolates of H. parviporum were evaluated by incubation on a solid malt extract medium at a temperature of 4℃, 15℃ and 21℃. Trichoderma antagonism against Heterobasidion was investigated in dual culture in vitro. The slowest rate of growth was referable to all seven strains of Heterobasidion spp. All Heterobasidion spp. strains were overgrown by 63% of Trichoderma spp. strains after two weeks at 21℃ and by 33% of strains at 15℃. 21% of Trichoderma strains did not grow and only four strains belonging to T. koningii, T. viride and T. viridescens demonstrated the ability to completely overgrow Heterobasidion spp. after two weeks incubation at 4℃. According to the antagonistic efficiency, Trichoderma strains were divided into five groups with an Euclidean distance of 25. The groups contained isolates from different species. It was suggested that selected psychrotrophic fast growing T. viride, T. koningii and T. viridescens strains could be examined in different substrate conditions as suitable antagonist agents for the control of H. annosum and H. parviporum.
文摘Synergism and antagonism of cadmium (Cd), copper (Cu) and selenium (Se) to biological toxicities in red soil, yellow brown soil and black soil were evaluated by MICROTOX method. The relation between forms of the tested metals in soil and the synergism or antagonism between them was also studied.Results showed that owing to the difference of soil chemical properties, toxicity of these metals in soils was different. In red soil with acid reaction and low in cation exchange capacity, antagonism occurred significantly between metals when they coexisted at high concentrations, while synergism occurred only under low concentrations. It is indicated that in red soil, toxicity of metals affected by synergism or antagonism depends on concentration of the metals present. For yellow brown soil and black soil with larger cation exchange capacity and lower exchangeable aluminium (A1), no toxicity of metals was observed even if metals were added to soil in high concentrations. Synergism and antagonism between Cd, Cu and Se were controlled by the forms of metals present. The amount of water-soluble metals was the most important factor in determining synergism and antagonism.In this paper, comparisons of synergism and antagonism between metals in soils and in water solutions were made. There occurred the synergism of metal toxicity in water solutions when the concentration of coexisting metals was high. This is just opposite to the case in soils.
文摘The local isolates of Trichoderma spp. and Fusarium solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch’s postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderma spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta.
文摘The world military situation in 2016was complex,military strategies of major countries undergoing profound readjustment,contest in emerging fields increasing and a new round of populism cropping up worldwide which resulted in'Black swan events'happening one after another,major-country contest and geopolitical conflicts piling up and local
文摘A strain B34 against Thanatephorus cucumeris was screened from rice plants. Lab and field experiments showed that the control effects of this fungal strain were better than that of Jinggangmycin on PDA plate. Based on the chemical components of cell wall and physiological and biochemical characters of B34, the fungal was named as Pseudomonas aureofaciens. It was a new antagonistic strain against Thanatephorus cucumeris.
文摘[ Objective] The aim of this study was to isolate the endophyte of three solanaceae fruits and vegetables such as tomato, pepper and eggplant, to screen and identify the bacterial wilt antagonistic bacteria. [ Methodl According to the lapping liquid culture method, the endophyte of three plants was isolated by the selective medium and purified by the plate streaking method, so the purified enclophyte was screened by the hyphal pieces confront culture method. Furthermore, the screened antagonistic and endophyteic bacteria was identified and classified through culture characteristics of isolates and morphological features of thallus, Gram stain as well as physiological and biochemical reactions. [ Result] Fifty-three endophytic bacteria, fifty-three endophytic fungi and forty-four endophytic actinomycetes were separated from the endophyte of three plants. The screened fourteen endophytic bacteria with strong antagonistic effect on the bacterial wilt were classified to Bacillus, Escherichia, Klebsiella, Agromonas, Erwinia and Curto Bacterium respectively. Especially, Bacillus was the dominant species, which had the strongest antagonistic effect on the bacterial wilt. [ Conclusion] This study provides an effective way for biological control of the bacterial wilt in solanaceae.
