Integration of Pseudomonas fluorescens and Rosemarinus officinalis for controlling of potato bacterial wilt (original) (raw)
Related papers
2013
The growing of potato plants in aeroponics system is considered as safe and ecologically friendly for producing natural, healthy plants and crops. However, it often faces with several constraints. Infection of bacterial wilt caused by Ralstonia solanacearum in the aeroponics cultivation system can spread rapidly through the nutrition flow and lead to plant death and crop failure. The objective of this study was to evaluate bacterial antagonist isolates belonging to Clostridium sp in reducing bacterial wilt disease of potato caused by Ralstonia solanacearum in aeroponic system and its effect on increasing the weight and number of potato tubers. The results showed that of the seven treatments tested on potato aeroponic system, treatment with a combination of isolates NS01 + G06 + S06 tend to be more effective in suppression of bacterial wilt disease (85%), increase the amount of seed tubers (162.5 tubers/treatment) and increase the average of tuber weight as much as 311.25 gr/treatmen...
2006
Ralstonia solanacearum is a very destructive pathogen that causes wilt in potato and many other solanacean crops in Ethiopia. In order to select effective antagonistic biocontrol agents for R. solanacearum strains, it is necessary to characterize the population of pathogenic strains. Therefore, 62 strains collected from wilted potato, tomato and pepper plants and potato tubers from the major potato producing regions of Ethiopia were characterized culturally and classified physiologically, based on their capacity to oxidize 3 disaccharides (lactose, maltose and cellobiose) and 3 hexose alcohols (mannitol, sorbitol and dulcitol). The results of this study indicated that all virulent strains from Ethiopia produce fluidal and irregular colonies with red centre and whitish periphery on triphenyl tetrazolium chloride (TZC) medium and irregular, fluidal, and creamy white colonies on casamino acids-pepton-glucose (CPG) medium. Physiologically, 19 strains were grouped to biovar I and 43 stra...
Cultural and biochemical properties of Ralstonia solanacearum causing bacterial wilt in potato
Ralstonia solanacearum, which causes bacterial wilt of diverse range of plants. Six isolates of Ralstonia solanacearum like bacteria in tetrazolium chloride (TZC) agar medium were collected from different Solanaceae crops (i.e. potato, tomato, chilli and Brinjal) at various sites in Meerut, of these, 4 strains were identified as R. solanacearum based on their cultural characteristics on TZC medium, The collection of four strains of R. solanacearum represent race 1 and race 3 of this pathogen. All the four strains represent presence of biovar II and III of R. solanacearum. Key words: Bacterial wilt, Ralstonia solanacearum, Solanaceae crops
Spanish Journal of Agricultural Research, 2016
Phytobiocides are a good alternative to chemicals in managing bacterial diseases including bacterial wilt of tomato caused by Ralstonia solanacearum. In the present research study, finely ground dried powders of seven widely available medicinal plants/weeds species viz., Peganum harmala (esfand or wild rue), Calotropis procera (sodom apple), Melia azedarach (white cedar), Allium sativum (garlic), Adhatoda vasica (malabar nut), Tagetes patula (marigold) and Nerium oleander (oleander) were assessed for their anti-microbial activity, both in-vitro (10% w/v) and in-vivo (10, 20, 30, and 40 g/kg of potted soil) against R. solanacearum. Aqueous extracts (prepared as 10% w/v, soaking for 48-72 h and filtering) of C. procera, A. vasica, and T. patula inhibited the in-vitro growth of the bacterial pathogen over 60% of that produced by the standard antibiotic streptomycin. A. sativum, N. oleander and P. harmala aqueous extracts were less effective while M. azedarach showed no effect against R...
African Journal of Food, Agriculture, Nutrition and Development
Ralstonia solanacearum is the causative agent of wilt disease in plants, which constitutes a severe problem to agricultural crops, particularly for potato production in Madagascar. The present study focuses on the isolation, in vitro and in vivo assays of potential rhizospheric and endophytic bacteria associated with healthy potato plant, capable to inhibit the growth of Ralstonia solanacearum for controlling potato bacterial wilt. A total of 77 bacteria strains were isolated from six soil rhizospheric samples and six vegetal material samples of healthy potatoes in the district of Antsirabe II. Forty of them were telluric actinomycetes, 25 were endophytic actinomycetes and 12 were fluorescent Pseudomonas spp. An additional 30 phytopathogenic isolates were obtained from six rhizopsheric soil samples of diseased potatoes. Morphological, cultural, biochemical characterization and molecular identification with the Ralstonia solanacearum specific primers 759/760 revealed that 24 of the p...
Egyptian Journal of Biological Pest Control, 2016
In vitro interactions between Ralstonia solanacearum and Bacillus subtilis, B. cereus, Pseudomonas fluorescens and Rhizobium phaseoli indicated that the first was affected by the tested antagonistic bacteria. P. fluorescens had the most growth potential and great inhibition to R. solanacearum on King's B agar medium, followed by R. phaseoli, B. cereus and B. subtilis, respectively. R. solanacearum showed a slight antagonistic effect against B. subtilis and B. cereus, while P. fluorescens and R. phaseoli did not respond to such effect. The interaction among the different tested bioagents revealed that P. fluorescens had a good growth potential and antagonism with B. subtilis and B. cereus. Biocontrol efficacy against R. solanacaerum and the effect on growth promotion of potato plants were investigated. B. subtilis, B. cereus, P. fluoresnces and R. phaseoli, when used individually caused different changes in biocontrol efficacy and growth promotion efficacy, being 50.0 and 4.7, 60.7and 12.0, 78.6 and 16.5, and 70.0 and 16.3%, respectively. Besides, not all the mixtures of antagonistic organisms can give good results,therefore detailed studies should be done first.
Effect of botanicals on Ralstonia solanacearum and bacterial wilt incidence in tomato
Tomato is considered as the second most important vegetable crop in India and major constraint in its production is bacterial wilt caused by Ralstonia solanacearum. The management of the disease is difficult and the chemicals are least effective and are hazardous. Hence, an alternate method of control needs to be developed which is effective, cheap and eco friendly. The water extract from only two botanicals viz., Ocimum gratissimum and Tylophora asthmatica were effective in inhibiting the growth of Ralstonia solanacearum. O. gratissimum extract showed highest inhibition zone of 28.66 mm at 1:0 dilution and had inhibitory effect upto 1:10 dilution with 22.66 mm inhibition zone. Alcohol extract of O. gratissimum was the most effective in inhibiting the growth of R. solanacearum followed by C. gigentea, O. sanctum, T. asthmatica, N. sativa and R. graveolens. Alcohol extract Ocimum gratissimum was found more efficacious than O. sanctum in delaying the onset of wilt disease wherein 100 per cent wilt incidence was observed at 56 DAI.
Microorganisms
Ralstonia solanacearum is one of the globally significant plant pathogens that infect a wide host range of economically important plants. A study was conducted to evaluate the hypothesis that an avirulent strain of R. solanacearum can act as a biocontrol mediator for managing potato bacterial wilt. Virulent R. solanacearum was isolated and identified (GenBank accession number; OP180100). The avirulent strain was obtained from the virulent strain through storage for 3 weeks until the development of deep red colonies. The virulent strain had higher lytic activity than the avirulent strain. Tubers’ treatments by the avirulent strain of R. solanacearum, (supernatant, boiled supernatant, and dead cells) significantly reduced plant disease rating and increased the growth, physiological activities, and biomass of potato compared to the untreated, infected control. The major components detected by GC–MS in the supernatant revealed 10.86% palmitic acid (virulent), and 18.03% 1,3-dioxolane, 2...
Journal of Plant Pathology, 2010
Bacterial wilt is an important disease of tomatoes and peppers, causing plant death and significant yield losses. Control methods include use of resistant varieties, crop rotation, etc. Biological control is desirable because control with other methods gives variable results. This paper describes the effectiveness of microbial antagonists isolated from soils. Of 73 isolated antagonists, eight were screened and evaluated in vitro and in vivo against Ralstonia solanacearum. They all significantly reduced disease symptoms. The effects of carbon and nitrogen source, incubation temperature and broth culture pH were evaluated for production of inhibitory substances. Results indicated that the optima were sucrose 2.5% (w/v), peptone 2% (w/v), temperature 28°C, and initial medium pH of 7. Three antagonists isolated from soil (Bacillus megaterium, Enterobacter cloacae, Pichia guillermondii) and Candida ethanolica showed high potential for disease suppression and also increased fruit weight, ...