An experiment was carried out to evaluate the fungitoxic effect of Trichoderma longibrachiatum (Rifai) metabolite on F. oxysporum, A. niger and A. tamarii. The fungi were collected from the International Institute of ...An experiment was carried out to evaluate the fungitoxic effect of Trichoderma longibrachiatum (Rifai) metabolite on F. oxysporum, A. niger and A. tamarii. The fungi were collected from the International Institute of Tropical Agriculture (IITA) and Nigerian Institute of Science Laboratory Technology (NISLT). T. longibrachiatum was cultured on 1/4 strength Potato Dextrose Broth (PDB) following standard procedures. Its metabolite was extracted using 50 ml n-hexane with 50 ml Potato Dextrose Broth (PDB). The metabolite was purified by filter sterilization using a sterile 0.22 millipore filter disc after centrifuging at 900 rpm for 20 minutes. Petri plates of each fungus were later impregnated in triplicates with the T. longibrachiatum metabolites using four concentrations (10%, 25%, 50% and 100%), and three volumes (1 ml, 2 ml, and 3 ml). Petri plates of fungi without the metabolite and Petri Plates of fungi with n-hexane and PDB served as control. All Petri Plates were incubated at 28°C for 7 days. Radial and diametric growth of each fungus on all Petri Plates were taken daily at 24 hours intervals. Data obtained were analysed using SAS (version 9.3). Growth inhibition of F. oxysporum, A. niger and A. tamarii was significantly higher than in control in that order (P ≤ 0.05). Inhibition of the fungi by metabolites extracted with both PDB and n-hexane was significantly better than in control. Generally, inhibition by metabolite extracted with PDB was better than that extracted with n-hexane. Growth inhibition at all the concentrations of the metabolite was significantly better than in the control (P ≤ 0.05). Generally, inhibition at 100%, 50% and 25% concentrations was better than that at 10% concentration of the metabolite. Trichoderma longibrachiatum metabolite can thus be said to possess promising fungitoxic potential even at concentrations as low as 25%. Both PDB and n-hexane are good extraction media for the metabolite.展开更多
This study investigates the potential of native biocontrol agents(BCAs)as controls against Ganoderma lucidum causing root rot mortality in Indian mesquite.The disease is prevalent in sandy soils where trees grow under...This study investigates the potential of native biocontrol agents(BCAs)as controls against Ganoderma lucidum causing root rot mortality in Indian mesquite.The disease is prevalent in sandy soils where trees grow under rainfed conditions.In addition,a beetle namely A canthophorus serraticornis damages the roots,resulting in increasing vulnerability of the host thereby allowing easy of the pathogen.In dual culture tests,Ganoderma infected cowpea root bit experiment and compatibility with insecticides revealed that the three BCAs(Trichoderma longibrachiatum,T.harzianum,and Aspergillus nidulans)significantly inhibited G.lucidum mycelial growth.The highest mycelial growth inhibition(47.6%)was recorded after 96 h followed by 39.8%and 29.3%at 72 and 48 h,respectively,by T.longibrachium.Cell free filtrates of T.longibrachiatum,T.harzianum,and A.nidulans were superior in inhibiting mycelium growth.A low concentration(3 ml)of T.longibrachiatum was more effective in inhibiting mycelium growth compared to other BCAs.Both P rosopis julifl ora compost and onion residue compost amendments as food substrates favored the growth of these BCAs,which ultimately reduced the viability of Ganoderma-colonized root bits of cowpea.Studies on compatibility between insecticides and BCAs suggests that T.longibrachiatum,harzianum and A.nidulans can be combined with phorate or chloropyriphos(both organophosphates)at variable concentrations if amended together for partially infected trees,or as a prophylactic measure in healthy trees.These studies demonstrate that there is considerable opportunity for using native BCAs against G.lucidum in managing root rot disease.展开更多
文摘An experiment was carried out to evaluate the fungitoxic effect of Trichoderma longibrachiatum (Rifai) metabolite on F. oxysporum, A. niger and A. tamarii. The fungi were collected from the International Institute of Tropical Agriculture (IITA) and Nigerian Institute of Science Laboratory Technology (NISLT). T. longibrachiatum was cultured on 1/4 strength Potato Dextrose Broth (PDB) following standard procedures. Its metabolite was extracted using 50 ml n-hexane with 50 ml Potato Dextrose Broth (PDB). The metabolite was purified by filter sterilization using a sterile 0.22 millipore filter disc after centrifuging at 900 rpm for 20 minutes. Petri plates of each fungus were later impregnated in triplicates with the T. longibrachiatum metabolites using four concentrations (10%, 25%, 50% and 100%), and three volumes (1 ml, 2 ml, and 3 ml). Petri plates of fungi without the metabolite and Petri Plates of fungi with n-hexane and PDB served as control. All Petri Plates were incubated at 28°C for 7 days. Radial and diametric growth of each fungus on all Petri Plates were taken daily at 24 hours intervals. Data obtained were analysed using SAS (version 9.3). Growth inhibition of F. oxysporum, A. niger and A. tamarii was significantly higher than in control in that order (P ≤ 0.05). Inhibition of the fungi by metabolites extracted with both PDB and n-hexane was significantly better than in control. Generally, inhibition by metabolite extracted with PDB was better than that extracted with n-hexane. Growth inhibition at all the concentrations of the metabolite was significantly better than in the control (P ≤ 0.05). Generally, inhibition at 100%, 50% and 25% concentrations was better than that at 10% concentration of the metabolite. Trichoderma longibrachiatum metabolite can thus be said to possess promising fungitoxic potential even at concentrations as low as 25%. Both PDB and n-hexane are good extraction media for the metabolite.
基金supported by the Core Research Grant of SERB–DST,New Delhi,Government of India。
文摘This study investigates the potential of native biocontrol agents(BCAs)as controls against Ganoderma lucidum causing root rot mortality in Indian mesquite.The disease is prevalent in sandy soils where trees grow under rainfed conditions.In addition,a beetle namely A canthophorus serraticornis damages the roots,resulting in increasing vulnerability of the host thereby allowing easy of the pathogen.In dual culture tests,Ganoderma infected cowpea root bit experiment and compatibility with insecticides revealed that the three BCAs(Trichoderma longibrachiatum,T.harzianum,and Aspergillus nidulans)significantly inhibited G.lucidum mycelial growth.The highest mycelial growth inhibition(47.6%)was recorded after 96 h followed by 39.8%and 29.3%at 72 and 48 h,respectively,by T.longibrachium.Cell free filtrates of T.longibrachiatum,T.harzianum,and A.nidulans were superior in inhibiting mycelium growth.A low concentration(3 ml)of T.longibrachiatum was more effective in inhibiting mycelium growth compared to other BCAs.Both P rosopis julifl ora compost and onion residue compost amendments as food substrates favored the growth of these BCAs,which ultimately reduced the viability of Ganoderma-colonized root bits of cowpea.Studies on compatibility between insecticides and BCAs suggests that T.longibrachiatum,harzianum and A.nidulans can be combined with phorate or chloropyriphos(both organophosphates)at variable concentrations if amended together for partially infected trees,or as a prophylactic measure in healthy trees.These studies demonstrate that there is considerable opportunity for using native BCAs against G.lucidum in managing root rot disease.
