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1.
Alkaloids and flavonoids of three plants, namely Withania somnifera, Euphorbia hirta and Terminalia chebula, were tested for their antifungal potential against plant pathogenic fungi Fusarium oxysporum. The spore counting technique was followed for the antibiotic properties of the extracts tested at three different concentrations (2.5, 5 and 10?mg/ml). Results revealed that the bound flavonoid of root of W. somnifera and free flavonoids of stem bark and fruits of T. chebula totally inhibited spore germination of the fungi (100%). The range of minimum inhibitory concentration and minimum fungicidal concentration of extracts recorded was 0.039–0.625 and 0.039–1.25?mg/ml, respectively. Bound flavonoids of selected plants were more effective than free flavonoids and alkaloids. The study suggests that both alkaloids and flavonoids extracts of selected plants have a potential antifungal properties for the control of diseases of various crops.  相似文献   

2.
Millet is an important crop threatened by soil-borne pathogenic fungi worldwide, but the position of these soil-borne fungi most especially Fusarium has not been evaluated in south-western Nigeria alongside their biocontrol using plant extracts. This study investigates the effects (in vitro and in vivo) of Moringa oleifera, Manihot esculenta (peels) and Senna alata at 5, 10 and 15% g/ml concentrations on Fusarium anthophilum, Fusarium verticillioides, Fusarium oxysporum and Fusarium scirpi. The in vivo experimental layout was arranged in a completely randomised design and all obtained data, both in vitro and in vivo, were statistically analysed using Minitab version 15. The extract of Moringa oleifera, Manihot esculenta (peels) and S. alata at 5, 10 and 15% g/ml concentrations showed significant (p?<?0.05) antagonistic effect in vitro and in vivo on F. anthophilum, F. verticillioides and F. oxysporum. Moringa oleifera and S. alata at 5 and 10% g/ml significantly (p?<?0.05) reduced the disease incidence and disease severity of F. scirpi on millet seedlings. Thus, Moringa oleifera appears to be the most effective extract followed by Manihot esculenta, while S. alata was the least effective plant extract. Hence, the effectiveness of plant extracts on pathogenic Fusarium of millet justified their management strategy geared towards sustainable millet growth in Nigeria.  相似文献   

3.
Yam is an important crop which serves as a source of income to small-holder farmers as well as a foreign exchange earner. Among the constraints faced by yam farmers are pests and diseases, especially deterioration caused by microbes during storage. Since over dependence on pesticides is being discouraged, neem seed and ginger extracts were evaluated as potential control agents against rot-causing fungi. The study was conducted in the Spanish laboratory, at the Faculty of Agriculture, University for Development Studies, Nyankpala Campus. Isolations were made from rotted yam tubers sampled from the Tamale Central market with potato dextrose agar (PDA) as the growth medium. Growth inhibition of the isolates was determined by growing pure cultures on PDA plates amended with 2?ml each of ethanol and aqueous extracts of neem seed and ginger as well as carbendazim. A pathogenicity test proved that Aspergillus flavus, A. niger, A. ochraceus and Penicillium digitatum isolated from the rotted tubers were responsible for the rot. A. niger had a significantly higher (p?<?0.05) occurrence (40%) than the others. Growth inhibitions by carbendazim and ethanol extracts of neem seed and ginger were comparable but significantly higher (p?<?0.05) than the aqueous extracts of neem seed and ginger as well as the control. However, the aqueous extracts of neem seed and ginger had a significantly higher (p?<?0.05) inhibition than the control. For instance, growth inhibition of A. niger by carbendazim, ethanol neem seed and ginger extracts were 70.5, 69.6 and 65.5%, respectively, while inhibition by aqueous neem seed and ginger extracts were 33.9 and 24.8%, respectively. Since aqueous extracts of neem seed and ginger significantly inhibited (p?<?0.05) growth of the rot-causing fungi, they can be used as surface protectants of stored tubers.  相似文献   

4.
Antimicrobial activities of rhizome extracts of Cyperus rotundus were investigated on selected plant pathogenic bacteria and fungi. Ethyl acetate and hexane extracts showed antibacterial activity against three isolates of Clavibacter michiganensis subsp. michiganensis at concentrations of 900 and 1000 μg/ml. However, Gram-negative bacterial pathogens of tomato; Pseudomonas syringae pv. tomato and Ralstonia solanacearum were not inhibited from the extracts. Ethyl acetate extracts at 100 μg/ml inhibited mycelial growth and spore germination of the two strawberry isolates of Botrytis cinerea; however, no significant inhibition was found in tomato fungal pathogen, Fusarium oxysporum f. sp. radicis lycopersici. Minimum inhibitory concentrations were determined as 0.0625 and 0.125 mg/ml against C. michiganensis subsp. michiganensis for ethyl acetate and hexane extracts of rhizomes, respectively. This study shows the potentials of extracts of C. rotundus rhizomes as antimicrobial agents that are effective against the tested plant pathogenic bacteria and fungi.  相似文献   

5.
The aims of this study were to evaluate the antifungal properties of Baccharis glutinosa and Ambrosia confertiflora extracts against Aspergillus flavus, A. parasiticus and Fusarium verticillioides, and to isolate the group of compounds that are responsible for the antifungal activity. Samples of aerial parts from each plant were extracted with 70% methanol and sequentially partitioned with hexane, ethyl acetate, and n-butanol. The partitioned fractions were evaluated in their capacity to inhibit the radial growth of the three species of fungi. The active fraction was used for an assay-guided chromatography of antifungal extracts. The results showed that the extract from B. glutinosa partitioned in ethyl acetate (Bea) showed the highest antifungal activity against the three fungi. Bea completely inhibited the growth of F. verticillioides at 0.8 mg/ml, whereas the radial growth of A. flavus and A. parasiticus was inhibited 70% at 1.5 mg/ml. The purified antifungal fraction from Bea showed 72, 54, and 52% of antifungal activity, respectively.  相似文献   

6.
This study investigates the use of botanical extracts (Piper guineense, Xylopia aethiopica and Bambusa vulgaris at 5, 10 and 15% concentration levels) for controlling deteriorating fungal pathogens in vitro. Identification of the fungal pathogens after pathogenicity test reaffirm isolates identity as Fusarium oxysporum, Fusarium solani, Macrophomina phaseolina, Fusarium verticillioides and Botryodiplodia theobromae. All the fungal pathogens induced rot in the watermelon fruit. The botanical extracts were best effective at high concentration levels (10 and 15%), though varied in their inhibitory activity. P. guineense and X. aethiopica were observed to be more effective than B. vulgaris. This study showed the efficacy of the botanical extracts on deteriorating fungal pathogens of watermelon fruit. Thus, the botanical extracts can be employed as antideteriorating biological-based fungicides for watermelon fruits.  相似文献   

7.
Isolation and identification of fungi associated with severe leaf blight of Thaumatococcus danielli was conducted. The fungi were subjected to pathogenicity test in the screenhouse experiment. Laboratory assessment of antifungicidal activities of; Ficus asperifolia, Psidium guajava, Mormodica charantia and Anarcadium occidentales prepared at 25, 50 and 75?mg/mL concentrations against the three most virulent pathogens was carried out on PDA, V8 Agar, CZA, and MEA culture media. Data gathered were subjected to ANOVA. Aspergillus niger, A. flavus, Pythium sp., Penicillium sp., Fusarium oxysporum, Macrophomina phaseolina, Trichoderma viride, T. koniigi and T. harzianum were the fungi found associated with the diseased parts and the rhizospheric soil. M. phaseolina, A. flavus and A. niger were the most virulent obtained in the pathogenicity test. Growths of these pathogens were mostly inhibited by M. charantia as its efficacy increased with increase in the concentration levels. Mycelia growths were mostly supported by MEA medium.  相似文献   

8.
The aim of the present study was to examine the efficacy of various seed extracts of Terminalia chebula as an antifungal potential against certain important plant pathogenic fungi. The organic extracts of methanol, ethyl acetate and chloroform at the used concentration of 1500 ppm/disc revealed remarkable antifungal effect as a fungal mycelial growth inhibitor against Fusarium oxysporum, Fusarium solani, Phytophthora capsici and Botrytis cinerea, in the range of 41.6–61.3%, along with MIC values ranging from 62.5 to 500 μg/ml. Also, the extracts had a strong detrimental effect on spore germination of all the tested plant pathogens along with concentration as well as time-dependent kinetic inhibition of B. cinerea. The results obtained from this study suggest that the natural products derived from Terminalia chebula could become an alternative to synthetic fungicides for controlling such important plant pathogenic fungi.  相似文献   

9.
The present study was designed to evaluate in vitro antifungal activity of herbal extracts against three plant pathogenic fungi (viz. Rhizopus stolonifer, Botrytis cinerea and Colletotrichum coccodes). Extracts of leaves and rinds of Garcinia indica, rhizomes of Curcuma aromatica, roots of Glycyrrhiza gahliae, leaves of Nyctanthes arbour-tristis and seeds of Vernonia anthelmintica were used for screening. Screening was done using poisoned food technique. Relatively potent extracts were shortlisted from this study and were further assayed to find out their minimum fungicidal concentration (MFC). From the above studies, it was observed that ethyl acetate extract of rhizomes of C. aromatica and unripe fruit rinds of G. indica have shown the lowest MFC values amongst the other tested plant extracts. This study indicates that the potential of these plant extracts in the management of diseases caused by plant pathogenic fungi.  相似文献   

10.
以发芽率、发芽势、根长、茎长和鲜重变化为种子萌发和幼苗生长参数,研究了作物红薯叶片水浸液对云南省农田5种恶性杂草牛膝菊、藿香蓟、鬼针草、马唐和稗草的化感作用。结果表明,红薯叶片水浸液对5种受体杂草种子发芽率的影响不明显,但对发芽势有显著抑制作用。牛膝菊、藿香蓟、鬼针草和马唐的根长和生物量随红薯叶片水浸液浓度增加而显著降低,其中对马唐的抑制最强,高浓度0.1 g/m L时对根长和生物量抑制率分别为92.04%和73.33%,而低浓度0.0125 g/m L时分别为40.99%和46.67%;其次为鬼针草、藿香蓟、牛膝菊;最差的是稗草,随浓度的变化趋势均不明显。随红薯叶片水浸液浓度增加牛膝菊、鬼针草和马唐的茎长显著地降低,其中对马唐的抑制最强,高浓度0.1 g/m L和低浓度0.0125 g/m L时分别为86.85%和70.64%;其次为鬼针草和牛膝菊;相反藿香蓟和稗草的茎长随浓度增加而显著增加,高浓度0.1 g/m L和低浓度0.0125 g/m L时对藿香蓟的促进率分别为86.97%和16.03%。红薯叶片水浸液低浓度0.0125 g/m L时对牛膝菊的茎长和生物量有促进作用(低促高抑)。从化感作用响应指数和综合效应指数的综合对比来看,红薯对牛膝菊、藿香蓟、鬼针草、马唐具有显著的化感抑制作用,随浓度增加其抑制能力显著增加;其中对马唐的为最强,其次为鬼针草、牛膝菊和藿香蓟,相反对稗草具有促进作用(除了浓度0.1 g/m L)。所有这些表明,红薯叶片水浸液对5种杂草化感作用的敏感性趋势总体为:马唐鬼针草牛膝菊藿香蓟,最不敏感或者具有促进作用的是稗草。  相似文献   

11.
Resistance to conventional fungicides causes poor disease control in agriculture. Natural products from plants have great potential as novel fungicide sources for controlling pathogenic fungi. In this study the antipathogenic activity of the leaf juices of 11 plant species (Chenopodium ambrosioides, Pulicaria vulgaris, Lavandula pubescens, Lavandula dentata, Ageratum conyzoides, Ficus retusa, Zizyphus nummularia, Acacia tortilis, Phragmanthera sp. Aff. Rufescens, Lawsonia alba and Olea europaea) were evaluated in vitro against three plant pathogenic fungi (Fusarium solani, Phytophthora spp. and Rhizoctonia solani). Plate assays showed that the leaf aqueous juices have antifungal activity against these fungi. The aqueous extracts of Pulicaria vulgaris, Lavandula dentata, Ageratum conyzoides, Ficus retusa, Zizyphus nummularia, Acacia tortilis, Phragmanthera sp. Aff. Rufescens (when associated with Acacia tortilis), Lawsonia alba and Olea europaea exhibited antifungal properties against Fusarium solani, Phytophthora spp. and Rhizoctonia solani with variable degrees. On the other hand, Chenopodium ambrosioides, Lavandula pubescens and Phragmanthera sp. Aff. Rufescens (when associated with Zizyphus nummularia) did not exhibit any fungitoxicity. All these observations suggest the possible exploitation of Chenopodium oil as a potential botanical fungitoxicant in ecofriendly control of post-harvest biodeterioration of food commodities from storage fungi.  相似文献   

12.
The inhibitory activity of five plant extracts viz. Artemisia absinthium L., Rumex obtusifolius L., Taraxacum officinale Weber ex Wiggers, Plantago lanceolata L. and Malva sylvestris L. were evaluated against the mycelial growth of three fungi Alternaria alternata (Fr.) Keissler, Penicillium expansum Link ex Thom. and Mucor piriformis Fisher that cause rot diseases in fruits and vegetables resulting in low yield and quality of fruits and vegetables. Results revealed that all the concentrations of plant extracts brought about significant inhibition in the mycelial growth of these pathogenic fungi. However, the highest concentration caused maximum inhibition in the mycelial growth followed by lower concentrations of plant extracts. The extract of A. absinthium leaves at highest concentration (S) proved highly effective in inhibiting the mycelial growth of all these pathogenic fungi followed by other plant extracts. These plants thus may have potential as the new natural fungicide for management of fungal rot diseases.  相似文献   

13.
A set of N-arylbenzenesulfonamides with various substituents at the arylamine and benzenesulfonyl positions were prepared, and their antifungal properties were measured in vitro against such plant pathogenic fungi as Pythium ultimum, Phytophthora capsici, Rhizoctonia solani, and Botrytis cinerea. Compounds 3, 4, 8, 9, 10, 14, 16, 18, 20, 21, 24 and 27 had antifungal activity over a broad spectrum of the phytopathogenic fungi tested, where 50% of inhibition (ED50) was in the range of 3-15 μg/ml. Based on the in vitro activity, six derivatives (3, 4, 10, 18, 21 and 27) were selected and tested further for their fungicidal efficacy in vivo. The fungicidal efficacy of 10, 21 and 27 had a disease control value of over 85% at 50 μg/ml against wheat leaf rust, while that of 4 was selective against cabbage club root disease.  相似文献   

14.
Many different species of fungi are often isolated from rotted cassava root tubers and pathogenicity studies have often implicated Botryodiplodia theobromae and Fusarium solani as the major causal pathogens. Consequently, more attention has often been focused on Botryodiplodia theobromae and Fusarium solani with little or no attention on the other minor pathogens. Considering the increasing importance of cassava to the Nigerian economy and the fact that minor root rot pathogens of cassava today could become major tomorrow, the aim of this research is to determine the incidence, pathogenicity and symptoms of the minor root rot pathogens in cassava from cassava fields within the derived savanna and the humid forest of Nigeria. Isolation of associated fungi was done on rotted root samples and the pathogenicity of these isolates were established by inoculating them into healthy cassava tuberous roots and subsequently reisolating them from resulting rotted tissue. The less frequently isolated fungi where Macrophomina sp., Trichoderma sp., Aspergillus niger, Aspergillus flavus, Sclerotium rolfsii and Fungus ‘A’ (a yet to be identified fungus). Repeated experiments confirmed a constant relationship between inoculated fungus and the resulting rotted tissue colour. The root rot tissue colours associated with inoculated pathogens in the laboratory were identical with the pathogens colony colour on potato dextrose agar.  相似文献   

15.
Aspergillus fumigatus causes severe problems in poultry production systems. Seven South African tree species were selected from the database of the Phytomedicine Programme based on its antifungal activity against the fungus Cryptococcus neoformans. The acetone leaf extracts of the selected species had minimum inhibitory concentrations (MICs) of 0.16 mg/ml and lower in the preliminary screening. The antibacterial and antifungal activities of hexane, dichloromethane, acetone and methanol extracts of the leaves were determined using a two-fold serial microdilution method against a range of commonly encountered animal pathogenic fungi (A. fumigatus, Candida albicans, C. neoformans, Microsporum canis and Sporothrix schenckii) and four nosocomial bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa). The plant species investigated were Combretum vendae (A.E. van Wyk) (Combretaceae), Commiphora harveyi (Engl.) Engl. (Burseraceae), Khaya anthotheca (Welm.) C.DC (Meliaceae), Kirkia wilmsii Engl. (Kirkiaceae), Loxostylis alata A. Spreng. ex Rchb. (Anacardiaceae), Ochna natalitia (Meisn.) Walp. (Ochnaceae) and Protorhus longifolia (Bernh.) Engl. (Anacardiaceae). All the extracts had activity against at least one of the test organisms over an incubation period of 24 or 48 h. The MIC values of the non-polar and intermediate polarity extracts of O. natalitia, K. anthotheca, C. vendae, C. harveyi, and P. longifolia had MICs as low as 0.08 mg/ml against at least one of the tested bacteria. Furthermore, the acetone extracts of L. alata, K. wilmsii, O. natalitia and C. vendae had antifungal activities with MIC values ranging from 0.04 to 0.08 mg/ml against at least one of the tested fungi. The average MIC values of the plant extracts against the different bacteria ranged from 0.17 to 2.11 mg/ml, while the range was 0.23–1.98 mg/ml for fungi. The Gram-positive bacteria (S. aureus and E. faecalis) were more susceptible to the plant extracts than the Gram-negative bacteria (E. coli and P. aeruginosa). E. faecalis was the most susceptible microbe and C. vendae extracts were the most active against nearly all the bacteria tested. The acetone extract of L. alata was the most active against fungal pathogens, with activity against at least 3 fungal organisms. L. alata was selected for further work to isolate compounds active against A. fumigatus and other fungal pathogens.  相似文献   

16.
Intercropping Ageratum conyzoides in citrus orchards may effectively suppress weeds and control other pests. Investigations showed that the inhibition of major weeds and soil pathogenic fungi in citrus orchards was significantly correlated with the allelochemicals released into the soil by intercropped A. conyzoides. Three flavones, ageratochromene, and its two dimers were isolated and identified from the A. conyzoides intercropped citrus orchard soil. These allelochemicals had different biological actions on major weeds and soil pathogenic fungi in the citrus orchard. Three flavones and ageratochromene could significantly inhibit the growth of weeds Bidens pilosa, Digitaria sanguinalis and Cyperus difformis, and spores germination of soil pathogenic fungi Phytophthora citrophthora, Pythium aphanidermatum and Fusarium solani. However, two dimers of ageratochromene had no inhibitory actions on them. The presence of these allelochemicals in soils suggests that they may be able to make a major contribution to control some weeds and diseases in citrus orchards. Further studies revealed that dynamic transformation between ageratochromene and its two dimers in the A. conyzoides intercropped citrus orchard soil was reversible, that is, ageratochromene released from ground A. conyzoides plants was transformed into its dimers, and the dimers can be remonomerized in the soils. However, this dynamic transformation did not occur in the soil with low organic matter and fertility. The dimerization was not correlated with microorganisms in the soil, but the biodegradation of both ageratochromene and its two dimers may have occurred, particularly in the soil with low organic matter and fertility. Our results strongly suggest that the reversible transformation between ageratochromene and its dimers in the A. conyzoides intercropped citrus orchard soil can be an important mechanism maintaining bioactive allelochemicals at an effective concentration, thus, sustaining the inhibition of weeds and pathogenic fungi in soil.  相似文献   

17.
The objective of this study was to evaluate the efficacy of the ethanolic extract of endemic plant Halacsya sendtneri in inhibiting the growing of the test fungi and bacteria as well as to determine its genotoxic potential and toxicity using the Allium anaphase-telophase assay. Minimum inhibitory concentrations (MIC) were determined for 15 indicator strains of pathogens, representing both bacteria and fungi. The highest susceptibility to the ethanolic extract of H.sendtneri was exhibited by Pseudomonas glycinea (FSB4), (MIC=0.09 mg/ml) among the bacteria, and by Phialophora fastigiata (FSB81), (MIC=1.95 mg/ml) among the fungi. The composition of H. sendtneri extracts was also determined using HPLC analysis. Rosmarinic acid was found to be the dominant phenolic compound. The Allium anaphase-telophase genotoxicity assay revealed that the ethanolic extract of H. sendtneri at concentrations of 31.5 mg/l and below does not produce toxic or genotoxic effects. This is the first report of chemical constituents, genotoxic and antimicrobial activities of the endemic species, H. sendtneri.  相似文献   

18.
Powders and extracts prepared from part and products of four plants species indigenous to Nigeria were tested under laboratory condition at 28?±?2?°C and 75?±?5% relative humidity for their insecticidal potential against Angoumois grain moth, Sitotroga cerealella. Adult S. cerealella were exposed to three concentrations at rate 0.5, 1 and 2?g of Capsicum frutescens, Cymbopogon citratus, Moringa oleifera and Anacardium occidentale powders and extracts at the rate of 1, 2 and 3%/20?g of wheat grains. Parameters evaluated were adult moth mortality, adult emergence and % hatchability in treated wheat grains after infestation. Results show that significant differences (p?<?0.05) existed among the powders and the concentrations. The powder of C. frutescens had the highest mortality rate of 100% after two?days of application at all tested concentrations. There were no adult emergence of moth in samples treated with C. frutescens and A. occidentale powders. The extracts completely killed all the adult moths introduced at all tested concentrations. The survival of the moth from egg to adult when treated with the plant powders showed that there was significantly (p?<?0.05) more adult in the control (71.3) compared to others. Extracts of all the tested plants were toxic to adult moth and also prevent hatching of the eggs of S. cerealella.  相似文献   

19.
This study reports the results of gas chromatography–mass spectrometry (GC–MS) analyses of the essential oil of Angelica archangelica L. (Apiaceae) roots, as well as its in vitro antifungal activity against 10 plant pathogenic fungi. Moreover, the essential oil was evaluated for its antifungal activity using the agar dilution method, and also minimum inhibitory concentrations and minimum fungicidal concentrations were determined. The major compounds identified by GC–MS were α-pinene (21.3%), δ-3-carene (16.5%), limonene (16.4%), and α-phellandrene (8.7%). The oil showed in vitro antifungal activity against some species of the Fusarium genus, Botrytis cinerea, and Alternaria solani. Our study indicates that the oil of A. archangelica could be used as a control agent for plant pathogenic fungi in natural formulations.  相似文献   

20.
Methanol and flavonoid extracts (free and bound) of Marchantia polymorpha L., Dryopteris filix-mas (L.) Schott and Ephedra foliata Boiss. were screened against three fungal plant pathogens: Alternaria solani, Fusarium oxysporum and Rhizoctonia solani. The extracts from D. filix-mas and E. foliata showed >80% of mycelial inhibition of A. solani whereas M. polymorpha and D. filix-mas (rhizome) completely inhibited the mycelial growth of R. solani when tested at highest concentration (5 mg/ml). Inhibition of spore germination of fungi (A. solani and F. oxysporum) was observed to be 100% by most of the extracts at 10 mg/ml. Moreover, plant extracts were found effective in increasing seed germination and seed vigour simultaneously thereby decreasing the percentage of pathogen infection. The results of the present study reveal that the plants screened possess the potential to inhibit the crop fungal pathogens and further investigation is required to explore the biologically active constituents of these plants and to use them as natural plant protectants for agriculture.  相似文献   

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