Genotypic variations in the inhibitory potentials of four combined botanicals on mycelia growth of Macrophomina phaseolina of cowpea [Vigna unguiculata (L) Walp.] (original) (raw)
Related papers
Macrophomina phaseolina, the causative agent of charcoal rot of cowpea and many other crops, is a devastating pathogen in many regions worldwide. Single control measures are ineffective or not feasible under farmers' conditions. In order to promote biological control as a component of an integrated management approach under arid ecological conditions, 20 bacterial antagonists were isolated from soil samples collected from the rhizosphere of healthy as well as M. Phaseolina-infected cowpea from fields located in the dry savannah zone of West Africa. In dual culture tests with four media, antagonistic activity was variable and depended on the medium used. Growth inhibition was generally good on tryptic soy agar on which two antagonists also inhibited microsclerotia production by M. phaseolina. Effective antagonists were identified as Bacillus subtilis, B. sphaericus and Paenibacillus polymixa. In greenhouse experiments, seed treatment with B. subtilis strain A11 reduced the incidence of M. phaseolina by 89.29% over the untreated control plants, and lower pathogen quantities in plants were confirmed by DAS-ELISA. Bacillus subtilis A11 was rhizosphere competent and maintained high population densities of up to 6 Log 10 CFU/g fresh weight on the roots and 5.73 Log 10 CFU/g fresh weight on the hypocotyls of cowpea plants over three weeks after inoculation. This antagonist is recommended for seed treatment in combination with other cultural practices for the management of M. phaseolina under arid conditions.
International Journal of Biological and Chemical Sciences, 2013
Macrophomina phaseolina, the causative agent of charcoal rot of cowpea and many other crops, is a devastating pathogen in many regions worldwide. Single control measures are ineffective or not feasible under farmers' conditions. In order to promote biological control as a component of an integrated management approach under arid ecological conditions, 20 bacterial antagonists were isolated from soil samples collected from the rhizosphere of healthy as well as M. Phaseolina-infected cowpea from fields located in the dry savannah zone of West Africa. In dual culture tests with four media, antagonistic activity was variable and depended on the medium used. Growth inhibition was generally good on tryptic soy agar on which two antagonists also inhibited microsclerotia production by M. phaseolina. Effective antagonists were identified as Bacillus subtilis, B. sphaericus and Paenibacillus polymixa. In greenhouse experiments, seed treatment with B. subtilis strain A11 reduced the incidence of M. phaseolina by 89.29% over the untreated control plants, and lower pathogen quantities in plants were confirmed by DAS-ELISA. Bacillus subtilis A11 was rhizosphere competent and maintained high population densities of up to 6 Log 10 CFU/g fresh weight on the roots and 5.73 Log 10 CFU/g fresh weight on the hypocotyls of cowpea plants over three weeks after inoculation. This antagonist is recommended for seed treatment in combination with other cultural practices for the management of M. phaseolina under arid conditions.
2019
Article History Received: July 16, 2019 Revised: September 12, 2019 Accepted: October 22, 2019 Natural plant extracts are valuable source of numerous fungitoxic compounds that can substitute synthetic fungicides. In current studies, six plant extracts viz., Zingiber officinalis, Eucalyptus camaldulensis, Azadirachta indica, Allium cepa, Cassia fistula and Allium sativum in three dose levels standard dose (S.D), S/2 and S/3 were tested against colony growth of Macrophomina phaseolina under in vitro conditions. Among all the treatments ginger extract at its standard dose was found highly effective followed by eucalyptus and neem. Percentage colony growth inhibition of (50 %), (38 %) and (29 %) was recorded to produce by ginger, eucalyptus and ginger respectively as compared to control treatment where no growth inhibition was recorded. Extract of Allium sativum was found least effective phytochemical where pathogenic fungal growth inhibition was (24.5 %). Concentration comparison of th...
Agriculture, Forestry and Fisheries, 2017
A screen house experiment was carried out to determine the effect of organic fertilizer, compost, inorganic fertilizer, and single super phosphate and Arbuscular mycorrhiza on damping-off disease of cowpea. The experimental design used was completely randomized design (CRD). There were fifteen treatments which were replicated three times. 2g of Macrophomina phaseolina (damping off disease) was infested on 10kg of soil sample in each pot with (30 by 75) cm spacing. Arbuscular mycorrhiza, compost (poultry based) and single super phosphate (SSP) were applied at the rate of 2250kg/ha, 1670kg/ha and 676kg/ha respectively. Three seeds of cowpea were sown into each pot, but later thinned into two plants per pot. Data on germination percentage at 7, 14, 21 and 28 days, number of leaves of cowpea at 2, 4, 6 and 8 weeks after planting, weight of pods per plant, incidence and severity at which pathogens affected the cowpea plant per treatment and growth yield of each treatment were collected and analyzed using analysis of variance (ANOVA) and means separated using the Duncan multiple range test. The plants that were treated with 676kg/ha single super phosphate produced higher cumulative weight of harvested fruits per plant followed by Arbuscular mycorrhiza, which did not have any negative effect on environment. The values of phosphorus in the post harvest soil analysis revealed that lower values of phosphorus were recorded in Single Super Phosphate treated pots, while plants treated with Arbuscular mycorrhiza at 500kgha-1 produced higher P value than the preplanting soil analysis indicating the absorption of large amount of the elements. It was therefore recommended that Arbuscular mycorrhiza could be used to optimize seed yield in cowpea.
In vitro mycelial sensitivity of Macrophomina phaseolina to fungicides
Pesquisa Agropecuária Tropical, 2013
Black root rot, caused by Macrophomina phaseolina (Tass.) Goid., is the most common root disease in soybean fields. This study aimed to determine the in vitro mycelial sensitivity, measured by the IC50 (concentration to inhibit 50% of the fungus mycelial growth) of a M. phaseolina isolate obtained from soybean, to different fungicides (thiram, iprodione, carbendazim, pyraclostrobin, fluquinconazol, tolyfluanid, metalaxyl and penflufen + trifloxystrobin), at six concentrations (0.01 mg L-1, 0.10 mg L-1, 1.00 mg L-1, 10.00 mg L-1, 20.00 mg L-1 and 40.00 mg L-1 of the active ingredient). The 0.00 mg L-1 concentration represented the control, without fungicide addition. The mycelial growth evaluation was performed with the aid of a digital pachymeter, by measuring the colonies diameter, when the fungus growth in the control treatment reached the Petri dish edge. The experimental design was completely randomized, with four replications. Concerning the fungitoxicity of active ingredients,...
Journal of Applied Biology & Biotechnology, 2017
Different growth media; PARP (Pimaricin + Ampicilin + Rifampicin + PCNB), Carrot Agar, Rye Agar and V8 Juice Agar were evaluated against mycelial growth of Phytophthora capsici. During isolation PARP was found the best medium as mean colony diameter of 2.2 cm was observed while no growth of P. capsici was found on any other media. Plant extracts Calotropis gigantean (Akk), Cassia fistula (Amaltas), Nerium oleander (Kaner), Oscimum basilicum (Niazbo), Parthenium hysterophorus (Parthenium) and Azadirachta indica (Neem) were assessed against mycelia growth of P. capsici in vitro. Parthenium hysterophorus totally inhibited the growth of P. capsici, Nerium oleander and Oscimum basilicum also prove effective to some extent. Although Azadirachta indica, Cassia fistula and Calotropis gigantea stimulated the growth of P. capsici.
Different growth media; PARP (Pimaricin + Ampicilin + Rifampicin + PCNB), Carrot Agar, Rye Agar and V8 Juice Agar were evaluated against mycelial growth of Phytophthora capsici. During isolation PARP was found the best medium as mean colony diameter of 2.2 cm was observed while no growth of P. capsici was found on any other media. Plant extracts Calotropis gigantean (Akk), Cassia fistula (Amaltas), Nerium oleander (Kaner), Oscimum basilicum (Niazbo), Parthenium hysterophorus (Parthenium) and Azadirachta indica (Neem) were assessed against mycelia growth of P. capsici in vitro. Parthenium hysterophorus totally inhibited the growth of P. capsici, Nerium oleander and Oscimum basilicum also prove effective to some extent. Although Azadirachta indica, Cassia fistula and Calotropis gigantea stimulated the growth of P. capsici.
Management of Macrophomina phaseolina by extracts of an allelopathic grass Imperata cylindrica
Pakistan Journal of Agricultural Sciences
The soil-borne fungal plant pathogen Macrophomina phaseolina (Tassi) Goid. causes rot disease in about 500 plant species worldwide. The present study was planned to assess the antifungal activity of an allelopathic grass Imperata cylindrica for the management of this devastating plant pathogen. In laboratory bioassays, various concentrations viz. 0, 0.5, 1.0, …, 3.0 g mL-1 of methanolic shoot, root and inflorescence extracts of the test allelopathic grass were appraised for their antifungal activity against the pathogen. Generally, higher concentrations of methanolic extracts of all the three parts of the grass exhibited variable antifungal activity. Shoot extract proved to be the most effective. All the concentrations of shoot extract significantly reduced the fungal biomass by 29–76% over control. Methanolic shoot extract was further fractionated using n-hexane, chloroform, ethyl acetate and n-butanol. In antifungal activity bioassays of these fractions, chloroform fraction was fo...
Efficacy of arbuscular mycorrhizal fungi (AMF) and Trichoderma viride was assessed biocontrol of Macrophomina phaseolina that causes charcoal rot in common bean plants (Phaseolus vulgaris L.) cv. Bronco. Pot experiment was used to evaluate the inhibitory effect of A. mycorrhizal fungi and T. viride in alginated (encapsulated) and free forms (unencapsulated) against M. phaseolina. The in vitro, results revealed that alginated and free T. viride showed the highest inhibition percentages (63.3 and 61.1%, respectively). Alginated AMF and T. viride significantly decreased the severity of the disease more than the free ones and slightly less than the chemical fungicide (Vitavax 200 40% FS). That positively affected dry weights of plant shoots and roots. Results significantly recorded more mycorrhiza colonization percent (73.7%) with alginated AM fungi and the least total fungal count with the fungicide treatment (0.56x10 5 spore/g dry rhizosphere). The chitinase enzyme significantly increased with alginated T. viride more than all other treatments, whereas alginated AM fungi significantly increased the antioxidant peroxidase enzyme activity. The highly increase of shoot protein content was achieved by alginated AM fungi (0.193 mg/g fresh weight), while alginated T. viride significantly gave the highest values of shoot proline and total phenols contents (0.0173µ mole/g and 0.263 mg/gm, respectively). Alginated T. viride still the unique one as it obtained the highest percentages of macroelments N (1.10), P (0.83) and K (0.95) %, respectively. Thus, the biocontrol agents and alginatedAM fungi and T. viride are considered the most promising effective bioagents to control M. phaseolina.
PATHOGENICITY OF Macrophomina SPECIES COLLECTED FROM WEEDS IN COWPEA
Revista Caatinga, 2020
Charcoal rot caused by Macrophomina phaseolina is a major cowpea disease causing substantial losses to growers. In the semi-arid region of Brazil, cowpea is one of the most widely used alternatives for crop rotation during the off-season of melon. This favors Macrophomina multiplication because both crops are hosts of this pathogen. The objective of this study was to verify the pathogenicity of Macrophomina phaseolina and M. pseudophaseolina on cowpea. The Macrophomina spp. isolates used were obtained from the roots of Trianthema portulacastrum and Boerhavia diffusa, weed species prevalent in melon production areas in North-east Brazilian. The experiment was carried out in a greenhouse. Cowpea plants cv. ‘Paulistinha’ were inoculated with 30 M. phaseolina isolates, 30 M. pseudophaseolina isolates and a reference isolate of M. phaseolina obtained from cowpea roots. All Macrophomina isolates were able to cause disease on cowpea and there were no statistical differences between both Ma...