| molecular detection of fusarium oxysporum f. sp. niveum and mycosphaerella melonis in infected plant tissues and soil. | we developed two species-specific pcr assays for rapid and accurate detection of the pathogenic fungi fusarium oxysporum f. sp. niveum and mycosphaerella melonis in diseased plant tissues and soil. based on differences in internal transcribed spacer (its) sequences of fusarium spp. and mycosphaerella spp., two pairs of species-specific primers, fn-1/fn-2 and mn-1/mn-2, were synthesized. after screening 24 isolates of f. oxysporum f. sp. niveum, 22 isolates of m. melonis, and 72 isolates from the ... | 2005 | 16019161 |
| cinnamic acid inhibits growth but stimulates production of pathogenesis factors by in vitro cultures of fusarium oxysporum f.sp. niveum. | long-term monoculture of watermelon leads to frequent occurrence of watermelon fusarium wilt caused by fusarium oxysporum f.sp. niveum (fon). some allelochemicals contained in watermelon root exudates and decaying residues are possibly responsible for promoting the wilt disease. the purpose of this study was to evaluate the allelopathic effect of artificially applied cinnamic acid on fon. results demonstrated that hyphal growth of fon was strongly inhibited by cinnamic acid. at the highest conce ... | 2008 | 18211014 |
| characterization of a regional population of fusarium oxysporum f. sp. niveum by race, cross pathogenicity, and vegetative compatibility. | abstract eighty-eight isolates of fusarium oxysporum f. sp. niveum, collected from wilted watermelon plants and infested soil in maryland and dela-ware, were characterized by cross pathogenicity to muskmelon, race, and vegetative compatibility. four isolates (4.5%) were moderately pathogenic to >/=2 of 18 muskmelon cultivars in a greenhouse test, and one representative isolate also was slightly pathogenic in field microplots. the four isolates all were designated as race 2, and were in vegetativ ... | 2007 | 18943287 |
| physiological and biochemical responses of in vitro fusarium oxysporum f.sp. niveum to benzoic acid. | the allelopathic potential of an artificially applied allelochemical, benzoic acid, on in vitro fusarium oxysporum f.sp. niveum (a soil-borne pathogen causing watermelon wilt) was evaluated. benzoic acid strongly inhibited its growth, sporulation and conidia germination, whereas it stimulated virulence factors of this pathogen. the biomass was reduced by 83-96 % and the conidia germinating rate and conidia production rate were decreased by 100 % at a concentration of >200 mg/l. however, phytopat ... | 2009 | 19418248 |
| antifungal activity from polar and non-polar extracts of some chenopodiaceae wild species growing in tunisia. | nine plants belonging to chenopodiaceae family were collected around salt marshes near monastir, located in the east mediterranean coast of tunisia. they were tested for their antifungal activities against six plant pathogenic fungi: botrytis cinerea, fusarium oxysporum f. sp. niveum, f. solani f. sp. cucurbitae, phytophthora cactorum, rhizoctonia solani and nattrassia mangiferae. data of this study showed that the highest inhibition of botrytis cinerea growth was observed with the petroleum eth ... | 2009 | 19452345 |
| rhizosphere soil microorganism populations and community structures of different watermelon cultivars with differing resistance to fusarium oxysporum f. sp. niveum. | fusarium wilt is an increasingly serious disease of watermelon that reduces crop productivity. changes in microorganism populations and bacterial and fungal community structures in rhizosphere soil of watermelon cultivars resistant or susceptible to fusarium oxysporum f. sp. niveum were investigated using a plate culture method and pcr-dgge analysis. plate culture showed that populations of culturable bacteria and actinomycetes were more abundant in the rhizosphere of the resistant watermelon cu ... | 2011 | 21529122 |
| growth responses of in vitro fusarium oxysporum f. sp. niveum to external supply of tannic acid. | allelochemicals released from root exudates or decaying residues of plants play diversified roles in ecological interactions of plant-pathogen. the objective of this work was to evaluate the allelopathic effect of an externally supplied tannic acid on soil-borne in vitro fusarium oxysporum f. sp. niveum. results showed that the tannic acid decreased the growth of the fungus up to 9.5% at 800 mg l(-1). conidial germination was reduced by 52.3% in comparison with the control. however, sporulation ... | 2010 | 21506492 |
| growth of in vitro fusarium oxysporum f. sp. niveum in chemically defined media amended with gallic acid. | gallic acid was artificially added to the media to grow fusarium oxysporum f.sp.niveum to investigate its effect on the pathogenic fungus. results indicate that gallic acid inhibited the growth of f. oxysporum f.sp.niveum. the colony diameter, the conidia germinating rate and the conidia yield were reduced by 5.7-22.9%%, 35.8-55.6% and 38.9-62.2% respectively. however, the virulence factors by the fungus were stimulated. the activity of pectinase, proteinase and cellulase increased by 12.3-627.8 ... | 2009 | 19915738 |
| saoussanabiloïde, a novel antifungal alkaloid from echiochilon fruticosum desf. growing in tunisia. | bioactivity guided fractionation of echiochilon fruticosum desf. (boraginaceae) butanolic extract biautography assay against fungi led to the isolation of a new bioactive alkaloid, named saoussanabiloïde (1). its structure was established on the basis of spectroscopic measurements, ir, ms and 2d nmr using cosy, hmqc and hmbc experiments. the strongest inhibitory effect of the butanolic extract, from fractions derived from the crude extract and saoussanabiloïde (1), were observed against fusarium ... | 2009 | 19844820 |
| in vitro physiological responses of fusarium oxysporum f. sp. niveum to exogenously applied syringic acid. | plant-microbe interactions are often accompanied by allelochemicals, such as syringic acid, released from the host plant. to explore the role of phenolic acids released from crop host plants in response to pathogen invasion, we examined the allelopathic effect of an artificially applied syringic acid on fusarium oxysporum f. sp. niveum. we demonstrated that the growth and the conidial germination rate of f. oxysporum f. sp. niveum were stimulated at lower concentrations of syringic acid, though ... | 2009 | 19602085 |
| chemical composition and antifungal activity of volatiles from three opuntia species growing in tunisia. | the chemical composition of the volatiles isolated by steam distillation from leaves, flowers and fruits of opuntia lindheimeri var. linguiformis l. benson, leaves and flowers of opuntia macrorhiza engelm and leaves of opuntia microdasys (lehmann) gathered in the sea cliff of monastir town (tunisia), has been studied by gc and gc-ms. remarkable differences were noted between the composition and the constituent percentage of the different studied organs. the most important compounds found in leav ... | 2007 | 19070119 |
| antibiotic effect of exogenously applied salicylic acid on in vitro soilborne pathogen, fusarium oxysporum f.sp.niveum. | salicylic acid, which is biosynthesized inside plant and is often found and accumulated in soil due to plant debris decaying, is considered as a signaling substance during plant-microbe interactions. it is involved in the cycling of biogeochemistry and related to plant resistance to biotic and abiotic stress. the antibiotic effect of salicylic acid on fusarium oxysporum f.sp.niveum (fon) was studied to investigate the relationships between the salicylic acid and the fungus in the ecological inte ... | 2008 | 18952255 |
| weakening and delayed mortality of fusarium oxysporum by heat treatment: flow cytometry and growth studies. | abstract survival of fusarium oxysporum f. sp. niveum following heat treatments was studied using flow cytometric, physiological, and microscopic assays. we exposed germinating conidia to sublethal temperatures from 36 to 42 degrees c for 60 min, followed by rhodamine 123 staining and flow cytometry, and found increasing levels of fluorescence that reflect a change in mitochondrial membrane potential, indicating a weakening induced by stress. viability of conidia or germinating conidia of the fu ... | 2002 | 18944020 |
| quantification of root and stem colonization of watermelon by fusarium oxysporum f. sp. niveum and its use in evaluating resistance. | abstract colonization of watermelon root and stem tissues by fusarium oxysporum f. sp. niveum race 1 and its relationship to the apparent resistance to fusarium wilt was investigated. in each of 2 years, 17 differentially susceptible watermelon cultivars and one accession were tested in the greenhouse, and 7 cultivars also were tested in the field. colonization by a chlorate-resistant marked isolate of the fungus was assayed by plating homogenized tissue samples on a selective medium. six days a ... | 2004 | 18943103 |
| inhibitory activity against plant pathogenic fungi of extracts from myoporum bontioides a. gray and indentification of active ingredients. | in order to understand the bioactivity of myoporum bontioides a. gray against plant pathogens and determine its active ingredients, the inhibitory activities of methanol extracts from m. bontioides against fusarium oxysporum f. sp. niveum (e. f. smith) snyder & hansen, pestalotia mangiferae p. henn., thielaviopsis paradoxa (de seynes) v. hohnel, colletotrichum musae (berk. & m. a. curtis) v. arx, alternaria alternata (fr.) keissler, mycosphaerella sentina (fr.) schroter and sphaceloma fawcettii ... | 2008 | 18069657 |
| change of biotransformation steps of formaldehyde cycle in water-melon plants after infection with fusarium oxysporum. | recent experiments indicate that the measurable formaldehyde (hcho) level is considerably elevated in the parts of water-melon plants immediately after a nonlethal infection with fusarium oxysporum f. sp. niveum. at the same time the level of some quaternary ammonium compounds (n(epsilon)-trimethyl-l-lysine, choline) as potential hcho generators (gene products) is considerably decreased. that is probably due to the fact that the alarm reaction phase of this biotic stress syndrome includes an int ... | 1998 | 10526980 |