bacterial parasite of a plant nematode: morphology and ultrastructure.the life cycle of a bacterial endoparasite of the plant-parasitic nematode meloidogyne incognita was examined by scanning and transmission electron microscopy. the infective stage begins with the attachment of an endospore to the surface of the nematode. a germ tube then penetrates the cuticle, and mycelil colonies form in the pseudocoelom. sporulation is initiated when terminal cells of the mycelium enlarge to form sporangia. a septum within each sporangium divides the forespore from the basal ...1977838678
scanning electron microscopy in nematode-induced giant transfer cells.a study of giant cells induced by the root-knot nematode, meloidogyne incognita, in roots of impatiens balsamina was made by scanning electron microscopy. the cytoplasmic contents of giant cells were removed by a procedure based on koh digestion, to reveal inner wall structure. wall ingrowths typical of transfer cells are present in giant cells from six days onwards after induction. they develop on walls adjacent to vascular tissues, and their distribution and development was examined. pit field ...19761001022
characterization of a pathogen-induced potato catalase and its systemic expression upon nematode and bacterial infection.we have isolated a cdna encoding a catalase (cat2st) by differential screening of a cdna library constructed from potato roots infected with the cyst nematode globodera pallida. expression analysis confirmed the local induction of cat2st and showed that it was highest at the adult stage of the parasite. it also revealed that cat2st was induced in uninfected roots, stems, and leaves of infected plants. localized and systemic induction of cat2st was also observed upon root-knot nematode (meloidogy ...19957655060
differential in vitro pathogenicity of predatory fungi of the genus monacrosporium for phytonematodes, free-living nematodes and parasitic nematodes of vitro tests were carried out on the pathogenicity of nine isolates of the predatory fungi of the genus monacrosporium (5 m. sinense isolates, 3 m. appendiculatum and 1 m. thaumasium isolate) for a phytonematode (second stage juveniles from meloidogyne incognita, race 3), a free-living nematode (panagrellus spp), and two gastrointestinal parasitic nematodes of cattle (infective larvae of cooperia punctata and haemonchus placei). a suspension containing 2,000 nematodes from each species was add ...199910347773
biochemical characterization of mi-eng1, a family 5 endoglucanase secreted by the root-knot nematode meloidogyne incognita.a beta-1,4-endoglucanase named mi-eng1, homologous to the family 5 glycoside hydrolases, was previously isolated from the plant parasitic root-knot nematode meloidogyne incognita. we describe here the detection of the enzyme in the nematode homogenate and secretion and its complete biochemical characterization. this study is the first comparison of the enzymatic properties of an animal glycoside hydrolase with plant and microbial enzymes. mi-eng1 shares many enzymatic properties with known endog ...200010824111
isolation of a novel collagen gene (mj-col-5) in meloidogyne javanica and analysis of its expression pattern.mj-col-5, isolated from the plant parasitic nematode meloidogyne javanica, has a longer carboxy-terminus than other members of the caenorhabditis elegans col-6 subfamily of cuticle collagen, including an extra tyrosine residue, and may form altered nonreducible cross-linkages. by semiquantitative determination at different life stages, mj-col-5 transcript was shown to be more abundant in eggs than in juveniles/young females and adult females. to characterize further this gene's contribution to t ...200111534644
the endosymbiosis-induced genes enod40 and ccs52a are involved in endoparasitic-nematode interactions in medicago truncatula.plants associate with a wide range of mutualistic and parasitic biotrophic organisms. here, we investigated whether beneficial plant symbionts and biotrophic pathogens induce distinct or overlapping regulatory pathways in medicago truncatula. the symbiosis between sinorhizobium meliloti and this plant results in the formation of nitrogen-fixing root nodules requiring the activation of specific genes in the host plant. we studied expression patterns of nodule-expressed genes after infection with ...200212437298
a sulfonic anhydride derivative from dibenzyl trisulphide with agro-chemical the present study, the biologically active natural product dibenzyl trisulphide (dts) which was previously isolated from the sub-tropical shrub petiveria alliacea was transformed to methyl benzyl sulphonic anhydride (mbsa) using a "one pot" transformation method. the anhydride was evaluated for anti-microbial activities on the bacteria, bacillus subtilis and pseudomonas fluorescens and found to be 2.5 fold more effective than the commercial agents isoniazid and ampicillin in inhibiting the gr ...200312668029
protein variability in meloidogyne spp. (nematoda:meloidogynidae) revealed by two-dimensional gel electrophoresis and mass protein variation as revealed by two-dimensional electrophoresis (2d-e) was studied in 18 isolates from populations of meloidogyne arenaria (six isolates), meloidogyne incognita (10 isolates), and meloidogyne javanica (one isolate) plus an unclassified isolate. gels (80 x 60 x 0.75 mm) were silverstained and digitized in order to compare their protein patterns. optical density and position of protein patterns were measured using statistical cluster analysis and computer-assisted image anal ...200212645913
potato-associated bacteria and their antagonistic potential towards plant-pathogenic fungi and the plant-parasitic nematode meloidogyne incognita (kofoid & white) study the effect of microenvironments on potato-associated bacteria, the abundance and diversity of bacteria isolated from the rhizosphere, phyllosphere, endorhiza, and endosphere of field grown potato was analyzed. culturable bacteria were obtained after plating on r2a medium. the endophytic populations averaged 10(3) and 10(5) cfu/g (fresh wt.) for the endosphere and endorhiza. respectively, which were lower than those for the ectophytic microenvironments, with 10(5) and 10(7) cfu/g (fresh ...200212455609
nematode-antagonistic trichothecenes from fusarium equiseti.a strain of the fungus fusarium equiseti isolated from soybean cyst nematode secretes nematode-antagonistic compounds. bioassay-guided fractionation of an extract of the culture broth was undertaken to identify the compounds. fractions were assayed for activity against a root-knot nematode (meloidogyne incognita), a plant pathogen that attacks the roots of numerous plant species. two trichothecene compounds were isolated that inhibited egg hatch and immobilized second-stage juveniles of this nem ...200111471940
molecular cloning and characterisation of a venom allergen ag5-like cdna from meloidogyne incognita.rna fingerprinting was used to identify rnas that were expressed in parasitic second-stage juveniles of meloidogyne incognita, but absent from or reduced in preparasitic second-stage juveniles. a cdna encoding a putative secretory protein was cloned from a m. incognita second-stage juvenile cdna library by probing with a 0.5kb fragment derived from fingerprinting that was more strongly expressed in parasitic second-stage juveniles. the cdna, named mi-msp-1, contained an open reading frame encodi ...200010675748
identification and characterization of excreted-secreted products and surface coat antigens of animal and plant-parasitic nematodes.nematode surface coat (sc) proteins and excreted-secreted products (e-s) are likely to play important roles in the host-parasite interaction and considerable similarities can be found in sc proteins and e-s products from certain plant and animal parasitic nematodes. monoclonal antibodies raised to e-s products of plant-parasitic nematodes were shown to cross-react with e-s products and the surface coats of the animal parasites trichinella spiralis and haemonchus contortus. most of the antibodies ...199910340331
secretory granule proteins from the subventral esophageal glands of the potato cyst nematode identified by monoclonal antibodies to a protein fraction from second-stage juveniles.sodium dodecyl sulfate-extracted proteins from second-stage juveniles (j2) of the potato cyst nematode globodera rostochiensis were fractionated by preparative continuous flow electrophoresis, and monoclonal antibodies (mabs) were raised against the 38- to 40.5-kda protein fraction. screening of the hybridoma culture fluids by immunofluorescence microscopy of j2 resulted in the identification of 12 mabs that bound specifically to the subventral esophageal glands. on western blots of j2 these mab ...19968589421
differential gene expression in nematode-induced feeding structures of transgenic plants harbouring promoter-gusa fusion constructs.sedentary plant-parasitic nematodes are able to induce specialized feeding structures in the root system of their host plants by triggering a series of dramatic cellular responses. these changes presumably are accompanied by a reprogramming of gene expression. to monitor such changes, a variety of promoter-gusa fusion constructs were introduced into arabidopsis and tobacco. transgenic plants were analysed histochemically for gus activity in the nematode feeding structures after infection with ei ...19938275103
the nematophagous fungus verticillium chlamydosporium produces a chymoelastase-like protease which hydrolyses host nematode proteins in situ.the nematophagous fungus verticillium chlamydosporium secreted several proteases in submerged culture in which soya peptone was the sole carbon and nitrogen source. one protease, vcp1 (m(r) 33,000, pi 10.2), was purified 14-fold from culture filtrates to apparent homogeneity using preparative isoelectric focusing in free solution, and shown to rapidly hydrolyse the chymotrypsin substrate suc-(ala)2-pro-phe-pna and elastin. vcp1 had a km for suc-(ala)2-pro-phe-pna of 4.3 x 10(-5) m and a kcat of ...19948000541
pasteuria thornei sp. nov. and pasteuria penetrans sensu stricto emend., mycelial and endospore-forming bacteria parasitic, respectively, on plant-parasitic nematodes of the genera pratylenchus and meloidogyne.descriptions are presented of two members of the pasteuria penetrans group of mycelial and endospore-forming bacteria, parasitic on plant-parasitic nematodes. in one case, the epithet p. penetrans sensu stricto emend. has now been limited to members of this group with cup-shaped sporangia and ellipsoidal endospores, parasitic primarily on the root-knot nematode meloidogyne incognita. the second organism, with rhomboidal sporangia and nearly spherical endospores, which is parasitic primarily on t ...19883382544
a species-specific oligonucleotide dna probe for the identification of meloidogyne incognita.a genomic library of meloidogyne incognita race 1 has been prepared in the bacteriophage lambda gt10 and screened for specific dna sequences by hybridization with radio-isotope labelled total genomic dna from a number of meloidogyne species. one clone isolated (mr1 #15), although not totally species specific, clearly showed preferential hybridization to m. incognita. following subcloning and sequencing of the 255 bp insert, four stretches of the sequence corresponding to oligonucleotides of appr ...19911745557
effects of plant growth promoting bacteria and composed organic fertilizers on the reproduction of meloidogyne incognita and tomato growth.glasshouse experiments were conducted to assess the influence of pseudomonas fluorescens, azotobacter chroococcum, azospirillum brasilense and composted organic fertilizers (cow dung, horse dung, goat dung and poultry manure) alone and in combination on the multiplication of meloidogyne incognita and growth of tomato. p. fluorescens was better at improving tomato growth and reducing galling and nematode multiplication than a. chroococcum or a. brasilense. among composted organic fertilizers, pou ...200415246448
development of a bionematicide with paecilomyces lilacinus to control meloidogyne incognita.root-knot disease caused by meloidogyne incognita is a matter of grave concern because it affects several economically important crop plants. the use of solid-state fermentation (ssf) may help to elaborate efficient formulations with fungi to be employed in the biologic control of nematodes. attempts were made to select low-cost substrates for spore production of a strain of paecilomyces lilacinus with known nematicide capacity. coffee husks, cassava bagasse, and defatted soybean cake were utili ...200415304741
safety of pochonia chlamydosporia var catenulata in acute oral and dermal toxicity/pathogenicity evaluations in rats and rabbits.the nematophagous fungus, pochonia chlamydosporia var. catenulata (kamyschlco ex barron & onions) zare & w-gams, was investigated as a potential biocontrol agent in integrated pest management strategy for meloidogyne incognita (kofoid and white) chitwood in vegetable crops in cuba. an acute oral and dermal toxicity/patogenicity study was performed to determine the safety of this fungus in non-target organisms. in the first study, a 1-dose level of 5 x 10(8) units of the microbial pest control ag ...200415487645
development of a new management strategy for the control of root-knot nematodes (meloidogyne spp) in organic vegetable production.the nematophagous fungus, pochonia chlamydosporia (goddard) zare & gams, has been investigated as a potential biological control agent for use in integrated pest management strategies for meloidogyne incognita (kof & white) chitwood in vegetable crops. the release of the fungus as a biological control agent requires a diagnostic method to monitor its spread in the environment and to gain knowledge of its ecology. only molecular methods are sufficiently discriminating to enable the detection of s ...200312587872
phenylacetic acid-producing rhizoctonia solani represses the biosynthesis of nematicidal compounds in vitro and influences biocontrol of meloidogyne incognita in tomato by pseudomonas fluorescens strain cha0 and its gm derivatives.the aim of the present investigation was to determine the influence of rhizoctonia solani and its pathogenicity factor on the production of nematicidal agent(s) by pseudomonas fluorescens strain cha0 and its gm derivatives in vitro and nematode biocontrol potential by bacterial inoculants in tomato.200515610416
pro domain peptide of hgcp-iv cysteine proteinase inhibits nematode cysteine proteinases.cysteine proteinases (cps) are synthesized as zymogens and converted to mature proteinase forms by proteolytic cleavage and release of their pro domain peptides. a cdna encoding a papain-like cp, called hgcp-iv, was isolated from a heterodera glycines j2 cdna library, expressed and utilized to assess the ability of its propeptide to inhibit proteinase in its active form. the hgcp-iv cdna sequence encodes a polypeptide of 374 amino acids with the same domain organization as other cathepsin l-like ...200415614726
genetics of resistance to meloidogyne incognita in crosses of grape rootstocks.progeny testing was used to investigate the value of selected grape varieties as parents in breeding nematode-resistant rootstocks. six pistillate-flowered rootstocks (ramsey, dog ridge, harmony, freedom, 1613c, and 161-49c) and four staminate-flowered rootstocks (riparia gloire, 3309c, 1616c, and st. george) were used. each male was crossed to each female. six weeks after inoculation with 1,500 second-stage juveniles of meloidogyne incognita race 3, roots were stained in an aqueous solution of ...200212582495
management of meloidogyne incognita on tomato by root-dip treatment in culture filtrate of the blue-green alga, microcoleus vaginatus.the nematicidal potential of culture filtrates of the blue-green alga, microcoleus vaginatus (cyanobacterium) was tested against meloidogyne incognita on tomato in pots under greenhouse conditions. prior to the transplantation of tomato seedling, roots were dipped in different concentrations (0.2%, 0.5%, 1%, 2%, 10%, 50% and 100%) of culture filtrate of m. vaginatus for 30 min. root-dip treatment reduced the root galling and final population of m. incognita and increased vegetative growth of pla ...200515792580
characterization of a cdna related to k-cl cotransporters in the root-knot nematode meloidogyne incognita.we report the cloning of a full-length cdna from the plant-parasitic nematode meloidogyne incognita, which encodes a putative protein of 1082 amino acids showing high similarity with k-cl cotransporters (kccs) from the free-living nematode caenorhabditis elegans (54% identity) and from a number of mammals, including human. hydropathy analysis indicates typical kcc topology patterns, with a hydrophylic nh2-terminal region, 12 membrane-spanning domains, and a long cooh-terminal hydrophylic region. ...200212180345
a novel root-specific gene, mic-3, with increased expression in nematode-resistant cotton (gossypium hirsutum l.) after root-knot nematode infection.a full-length cdna, mic-3, has been identified from a lambda zapii cdna library constructed from the mrna of nematode-resistant cotton (gossypium hirsutum l.) roots after infection with root-knot nematode (meloidogyne incognita). the putative open reading frame of mic-3 encoded a protein of 141 amino acids with a calculated molecular mass of 15.3 kda. seven alternative polyadenylation sites have been identified for the mic-3 transcripts, and the major transcripts are the longest ones. the mic-3 ...200212031505
changes in the lipophilicity of the surfaces of meloidogyne incognita and haemonchus contortus during exposure to host signals.the surfaces of plant and animal parasitic nematodes share certain lipids, which seem to be important in the infection process. the surfaces of 2 parasitic nematodes, meloidogyne incognita and haemonchus contortus, were activated by different ph buffers to allow the insertion of different fluorescent probes. the lipid analogue pkh26 and the surface charge indicator, cationized ferritin, were used as probes with these nematodes but labelled only the retaining 2nd-stage moulted cuticle of h. conto ...200010726281
a secretory cellulose-binding protein cdna cloned from the root-knot nematode (meloidogyne incognita).a cdna encoding a secretory cellulose-binding protein was cloned from the root-knot nematode (meloidogyne incognita) with rna fingerprinting. the putative full-length cdna, named mi-cpb-1, encoded a 203 amino acid protein containing an n-terminal secretion signal peptide. the c-terminal sequence of the putative mi-cbp-1 was similar to a bacterial-type cellulose-binding domain, whereas the n-terminal sequence did not show significant similarity to any proteins in data bases. recombinant mi-cbp-1 ...19989768512
identification and analysis of a cuticular collagen-encoding gene from the plant-parasitic nematode meloidogyne incognita.the vast majority of proteins in the nematode cuticle are collagens. cuticular collagen-encoding genes (col) have been described for the animal parasites ascaris suum and haemonchus contortus and for the free-living caenorhabditis elegans. the proteins encoded by all these genes seem to have the same basic structure, indicating that there is a conserved subfamily of cuticular col in these nematodes. in this paper, we describe the identification and characterization of a cdna (lemmi 5) which corr ...19947828882
tylenchida associated with field crops in tehran and central provinces of iran.on a survey of plant parasitic nematodes, belonging to the order tylenchida, about 500 soil and root samples were collected from different field crops, such as wheat, barley, tomato, potato, corn, beets, eggplants, cuccumber, melon and also other crops cultivated in tehran and central provinces during 1995-2000. all samples were washed and the nematodes were extracted by centrifugal flotation technique. they were fixed and transferred to glycerin, then permanent slides were mounted. morphologica ...200212696441
a major gene mapped on chromosome xii is the main factor of a quantitatively inherited resistance to meloidogyne fallax in solanum sparsipilum.meloidogyne fallax is an emerging pest in europe and represents a threat for potato production. we report the mapping of genetic factors controlling a quantitative resistance against m. fallax identified in the solanum sparsipilum genotype 88s.329.15. when infected, this genotype develops a necrotic reaction at the feeding site of the juveniles and totally prevents their development to the female stage. a "f1" diploid progeny consisting of 128 individuals was obtained using the potato (s. tubero ...200616365760
induced systemic resistance of selected endophytic bacteria against meloidogyne incognita on previous work, the four endophytic bacteria pantoea agglomerans mk-29, cedeca davisae mk-30, enterobacter spp. mk-42 and pseudomonas putida mt-19 were shown to reduce meloidogyne incognita on tomato when applied as a seed treatment and/or soil drench. the objective of this work was to study these bacteria for their potential to induce systemic resistance against root knot nematodes on tomato. to guarantee spatial separation between inducing agent and pathogen a split-root system was chosen an ...200112425091
influence of plant species on the biological control activity of the antagonistic rhizobacterium rhizobium etli strain g12 toward the root-knot nematode, meloidogyne incognita.the influence of plant species on the antagonistic activity of the rhizosphere bacterium rhizobium etli g12 towards the root-knot nematode meloidogyne incognita was studied. the crops tested were tomato, cucumber, cotton, soybean and pepper. the plants were evaluated for the following parameters: root gall-index, total number of galls and egg masses of m. incognita, as well as shoot and root fresh weight and root length. results indicated a clear influence of plant species on the ability of r. e ...200112425090
effects of phytohormones on the surfaces of plant-parasitic nematodes.the direct effects of phytohormones (auxin and kinetin) and root diffusates on the surface lipophilicity of the plant parasitic nematodes globodera rostochiensis and meloidogyne incognita were investigated. the fluorescent lipid probe af18 (5-n(octodecanoyl) aminofluorescein) was used to detect surface changes. root diffusates increased af18 uptake by g. rostochiensis while it had no effect on m. incognita. kinetin and auxin decreased af18 uptake in g. rostochiensis, while they had the opposite ...200212211609
identification and in situ and in vitro characterization of secreted proteins produced by plant-parasitic nematodes.secretions of plant-parasitic nematodes which are released into plant tissue may play critical roles in plant-nematode interactions. the identification and characterization of these molecules are of fundamental importance and may help to facilitate the development of novel strategies to interfere with nematode infection of plants and thereby decrease nematode-induced damage to crops. an antibody-based approach was used to isolate molecules present on the nematode surface and in nematode secretio ...19968939056
characterisation of potential adhesins of the bacterium pasteuria penetrans, and of putative receptors on the cuticle of meloidogyne incognita, a nematode host.pasteuria penetrans spores were fragmented by glass bead vortexing, producing exosporial membranes and spore fragments, which consisted of fibre bundles. both exosporia and spore fragments are capable of host-specific attachment to the cuticle of meloidogyne incognita, a root-knot nematode host. putative m. incognita receptors appear to be soluble in beta-mercaptoethanol (bme) but not sds, and are also sensitive to tryptic digestion and deglycosylation by endoglycosidase f. polyclonal antibodies ...19911808209
nematicidal activity of some sri lankan plants.nineteen solvent extracts from seven sri lankan plants were examined for nematicidal activity against the root knot nematode meloidogyne incognita. extracts of allophyhu cobbe, lepisanthes tetraphylla (sapindaceae), sarcococca zeylanica (buxaceae) and hedyotis lawsoniae (rubiaceae) have shown significant nematicidal activity.200312822904
effects of arbuscular mycorrhizal fungi and a non-pathogenic fusarium oxysporum on meloidogyne incognita infestation of tomato.arbuscular mycorrhizal (am) fungi and non-pathogenic strains of soil-borne pathogens have been shown to control plant parasitic nematodes. as am fungi and non-pathogenic fungi improve plant health by different mechanisms, combination of two such partners with complementary mechanisms might increase overall control efficacy and, therefore, provide an environmentally safe alternative to nematicide application. experiments were conducted to study possible interactions between the am fungus glomus c ...200312938032
expression and functional characterization of a single chain fv antibody directed against secretions involved in plant nematode infection process.expression in plants of antibodies directed against proteins essential for pathogenesis could provide an alternative approach to engineer new resistance traits into crops. salivary secretions of the root-knot nematode meloidogyne incognita are known to play a key role during this nematode infection process. from a hybridoma cell line producing an igm monoclonal antibody specific to these secretions, we have constructed a synthetic gene that encodes an antigen-binding single-chain fv protein (scf ...19968645292
a polygalacturonase of animal origin isolated from the root-knot nematode meloidogyne incognita.the first animal polygalacturonase (pg, ec 2.1.15) encoding cdna, mi-pg-1, was cloned from the plant parasitic nematode meloidogyne incognita. the enzymatic activity of mi-pg-1 was confirmed after heterologous expression in escherichia coli. the presence of a predicted signal peptide on the mi-pg-1 sequence together with the specific localization of the transcripts of the mi-pg-1 gene in the oesophageal glands of infective juveniles imply that mi-pg-1 could be secreted into plant tissues. the po ...200212095628
solubilization of insoluble zinc compounds by gluconacetobacter diazotrophicus and the detrimental action of zinc ion (zn2+) and zinc chelates on root knot nematode meloidogyne examine the zinc (zn) solubilization potential and nematicidal properties of gluconacetobacter diazotrophicus. methods and results: atomic absorption spectrophotometer, differential pulse polarography and gas chromatography coupled mass spectrometry were used to estimate the total zn and zn(2+) ions and identify the organic acids present in the culture supernatants. the effect of culture filtrate of zn-amended g. diazotrophicus pal5 on meloidogyne incognita in tomato was examined under gnotob ...200717309498
induction of the hahsp17.7g4 promoter by root-knot nematodes: involvement of heat-shock elements in promoter activity in giant cells.root-knot nematodes feed from specialized giant cells induced in the plants that they parasitize. we found that the promoter of the hahsp17.7g4 gene, which encodes a small heat-shock protein involved in embryogenesis and stress responses, directed gus expression in tobacco galls induced by the root-knot nematode meloidogyne incognita. in roots containing a gus reporter fusion to the hahsp17.7g4 promoter, 10% of the galls stained for gus expression 1 to 3 days after infection and the fraction sta ...200314651339
morphological variability and molecular phylogeny of the nematophagous fungus monacrosporium isolate of the nematode-trapping fungus monacrosporium drechsleri was collected from cultures of the root-knot nematode meloidogyne arenaria that had been maintained on tomato roots in greenhouse pots in beltsville, maryland. the plant-parasitic nematodes heterodera glycines, meloidogyne incognita and pratylenchus zeae and the free-living nematodes caenorhabditis elegans and panagrellus redivivus were placed on colonies of m. drechsleri grown in petri dishes to study ability of the isolate to ...200516396348
biological activities of an extract from cleome viscosa l. (capparaceae).electron micrograph examination of the leaf and stem surfaces of cleome viscosa l (family capparaceae) revealed the presence of secretory glandular trichomes with club-cylinder and cylinder morphologies. in the present study, the leaves and stems of c. viscosa were extracted with hexane and the extract was evaluated for the following biological activities: anti-bacterial, anti-fungal, contact insecticidal and nematicidal. the extract was found to be a potent anti-bacterial agent according to the ...200314564407
a plant growth promoting rhizobacterium, paenibacillus polymyxa strain gbr-1, suppresses root-knot nematode.exposure of root-knot nematode, meloidogyne incognita to various concentrations (5-100%) of culture filtrate of paenibacillus polymyxa gbr-1 under in vitro conditions significantly reduced egg hatch and caused substantial mortality of its juveniles. the increase in the exposure durations of juveniles to culture filtrate and its concentrations increased the mortality rate. similarly, higher concentrations increased its inhibitory effect on egg hatch. in higher concentrations (25-100%) egg hatch w ...200817706411
ex vitro composite plants: an inexpensive, rapid method for root biology.plant transformation technology is frequently the rate-limiting step in gene function analysis in non-model plants. an important tool for root biologists is the agrobacterium rhizogenes-derived composite plant, which has made possible genetic analyses in a wide variety of transformation recalcitrant dicotyledonous plants. the novel, rapid and inexpensive ex vitro method for producing composite plants described in this report represents a significant advance over existing composite plant inductio ...200516045479
efficacy of paecilomyces lilacinus (strain 251) for the control of root-knot nematodes.the egg pathogenic fungus paecilomyces lilacinus (strain 251), is a unique strain with a wide range of activity against the most important plant parasitic nematodes. due to increased production capacity by solid state fermentation and a new water dispersible granule (wdg) formulation, this biological nematicide may be used in an integrated approach to control plant parasitic nematodes. dose response experiments were conducted with the root-knot nematode meloidogyne incognita on tomatoes using th ...200315149100
extracellular protease of pseudomonas fluorescens cha0, a biocontrol factor with activity against the root-knot nematode meloidogyne pseudomonas fluorescens cha0, mutation of the gaca-controlled apra gene (encoding the major extracellular protease) or the gaca regulatory gene resulted in reduced biocontrol activity against the root-knot nematode meloidogyne incognita during tomato and soybean infection. culture supernatants of strain cha0 inhibited egg hatching and induced mortality of m. incognita juveniles more strongly than did supernatants of apra and gaca mutants, suggesting that apra protease contributes to biocontro ...200516151170
expression of an arabidopsis phosphoglycerate mutase homologue is localized to apical meristems, regulated by hormones, and induced by sedentary plant-parasitic nematodes.we previously isolated a partial soybean cdna clone whose transcript abundance is increased upon infection by the sedentary, endoparasitic soybean cyst nematode heterodera glycines. we now isolated the corresponding full-length cdna and determined that the predicted gene product was similar to the group of cofactor-dependent phosphoglycerate mutase/bisphosphoglycerate mutase enzymes (pgm/bpgm; ec we designated the corresponding soybean gene gmpgm. pgm and bpgm are key catalysts ...200315010616
isolation and characterization of another cdna encoding a chorismate mutase from the phytoparasitic nematode meloidogyne arenaria.a new cdna, named ma-cm-2, encoding a chorismate mutase (cm), has been isolated from meloidogyne arenaria. the full-length cdna, carrying the trans-spliced sl1 leader sequence, was 753-bp long with an open reading frame of 576 bp. the deduced protein ma-cm-2 including amino-terminal signal peptide shows significant similarity to cms of meloidogyne incognita, meloidogyne javanica, and also bacteria. secondary structure prediction of ma-cm-2 indicates the presence of the three conserved alpha-heli ...200616458297
3-hydroxypropionic acid as a nematicidal principle in endophytic fungi.3- hydroxypropionic acid was isolated by bioactivity-guided fractionation of extracts obtained from submerged cultures of several endophytic fungi isolated from above-ground plant organs. this compound showed selective nematicidal activity against the plant-parasitic nematode meloidogyne incognita with ld50 values of 12.5-15 microg/ml. activity against the saprophytic caenorhabditis elegans was fivefold lower. no antimicrobial, cytotoxic or phytotoxic effects were observed. propionic acid and d- ...200415587708
papain-like cysteine proteases: key players at molecular battlefields employed by both plants and their invaders.papain-like cysteine proteases (plcps) play crucial roles in plant-pathogen/pest interactions. during these parasitic interactions, plcps act on non-self substrates, provoking the selection of counteracting inhibitors and other means to evade proteolysis. we review examples of plcps acting on molecular battlefields in the extracellular space, plant cytoplasm and herbivore gut. examples are maize mir1 (maize inbred resistance 1), tomato rcr3 (required for cladosporium resistance-3), pseudomonas a ...200818705889
an easy method using glutaraldehyde-introduced fluorescence for the microscopic analysis of plant biotrophic interactions.the method introduced in this article makes use of the glutaraldehyde-induced auto-fluorescence of proteins after cross-linking with glutaraldehyde for the analysis of cellular and sub-cellular structures. because the interface of biotrophic interactions is rich in proteins, the method presented is particularly suitable for the analysis of such interactions; we have exemplified its usefulness by analyzing (1) the root feeding sites induced in roots from arabidopsis thaliana by the root-knot nema ...200818778431
location of independent root-knot nematode resistance genes in plum and peach.prunus species express different ranges and levels of resistance to the root-knot nematodes (rkn) meloidogyne spp. in myrobalan plum ( prunus cerasifera), the dominant ma gene confers a high-level and wide-spectrum resistance to the predominant rkn, meloidogyne arenaria, meloidogyne incognita, meloidogyne javanica and the isolate meloidogyne sp. florida which overcomes the resistance of the amygdalus sources. in japanese plum ( prunus salicina), a similar wide-spectrum dominant resistance gene, ...200414569426
impact of the nematophagous fungus pochonia chlamydosporia on nematode and microbial populations.the microbial and nematode populations associated with two plants (tomato and cabbage) inoculated with the nematophagous fungus, pochonia chlamydosporia var. chlamydosporia or root knot nematode (meloidogyne incognita), or both, were compared with those in unplanted controls. the dominant factor affecting culturable microbial populations was found to be the presence or absence of tomato plants. generally microbial colony counts were lowest in unplanted soil, small increases were associated with ...200516363363
purification and characterization of chitinases from paecilomyces variotii dg-3 parasitizing on meloidogyne incognita eggs.two extracellular chitinases were purified from paecilomyces variotii dg-3, a chitinase producer and a nematode egg-parasitic fungus, to homogeneity by deae sephadex a-50 and sephadex g-100 chromatography. the purified enzymes were a monomer with an apparent molecular mass of 32 kda (chi32) and 46 kda (chi46), respectively, and showed chitinase activity bands with 0.01% glycol chitin as a substrate after sds-page. the first 20 and 15 n-terminal amino acid sequences of chi32 and chi46 were determ ...200918936994
resistance to root-knot nematode in tomato roots expressing a nematicidal bacillus thuringiensis crystal protein.our laboratory has demonstrated previously that bacillus thuringiensis (bt) crystal (cry) proteins present in the cry5 and cry6 subclades intoxicate free-living nematodes. in this study, we tested whether the expression of nematicidal cry6a in transgenic plants provided protection against plant-parasitic nematodes. as bacterial codon usage is incompatible with expression in plants, two different codon-modified cry6a genes were synthesized for expression in plants. one was designed by maintaining ...200717451491
a fusarium wilt resistance gene in gossypium barbadense and its effect on root-knot nematode-wilt disease complex.abstract fusarium wilt, caused by the soilborne pathogen fusarium oxysporum f. sp. vasinfectum race 1, is a vascular disease in cotton (gossypium spp.), and is a component of a disease complex with root-knot nematodes (meloidogyne incognita). genetic analysis of two interspecific crosses (g. barbadense pima s-7 x g. hirsutum acala nemx and pima s-7 x acala sj-2) showed that one major gene (designated fov1) with allele dosage effect conferred resistance to f. oxysporum f. sp. vasinfectum race 1 i ...200618943146
optimizing the efficacy of paecilomyces lilacinus (strain 251) for the control of root-knot nematodes.the egg pathogenic fungus paecilomyces lilacinus (strain 251) is a biocontrol fungus with a potential range of activity to control the worldwide most important plant parasitic nematodes. this biological nematicide may be an useful tool in an integrated approach to control mainly sedentary nematodes. greenhouse experiments were conducted with the root-knot nematodes meloidogyne incognita and m. hapla on tomato. p. lilacinus, formulated as wg (bioact wg), was incorporated into soil inoculated with ...200415759437
potential of olive mill waste and compost as biobased pesticides against weeds, fungi, and nematodes.the phytotoxic and antimicrobial properties of olive mill wastes have been widely investigated and demonstrated over the past decade. however, their potential utilization as biodegradable pesticides against plant pathogens is still poorly understood. in this study, a series of laboratory bioassays was designed to test the inhibitory effects of sterile water extracts of two-phase olive mill waste (tpomw) and tpomw composts with different degrees of stabilization on several different plant pathoge ...200818471866
biological control potential of the obligate parasite pasteuria penetransagainst the root-knot nematode, meloidogyne incognita infestation in brinjal.the efficacy of the obligate bacterial parasite, pasteuria penetrans against the rootknot nematode, meloidogyne incognita infestation was assessed in brinjal. the seedling pans with sterilized soil were inoculated with nematodes and root powder of p. penetrans were applied at different dosages viz., 0 x 10(6), 0.5 x 10(6) spores and 1 x 10(6) spores/pan. seeds of brinjal cv co2 were sown in the pans and seedlings were allowed to grow. the seedlings were transplanted to microplots containing ster ...200516628937
effect of a formulation of bacillus firmus on root-knot nematode meloidogyne incognita infestation and the growth of tomato plants in the greenhouse and nursery.bacillus firmus, commercial wp formulation (bionem) was evaluated against the root-knot nematode meloidogyne incognita in a laboratory, greenhouse and under field conditions on tomato plants. in the laboratory tests, an aqueous suspension of bionem at 0.5%, 1%, 1.5% and 2% concentration reduced egg hatching from 98% to 100%, 24-days after treatment. treatment of second-stage juveniles with 2.5% and 3% concentration of bionem, caused 100% inhibition of mobility, 24 h after treatment. in the green ...200919041655
integrated management of root-knot nematode, meloidogyne incognita infestation in tomato and integrated approach with the obligate bacterial parasite, pasteuria penetrans and nematicides was assessed for the management of the root-knot nematode, meloidogyne incognita infestation in tomato and grapevine. seedlings of tomato cv. co3 were transplanted into pots filled with sterilized soil and inoculated with nematodes (5000 juveniles/pot). the root powder of p. penetrans at 10 mg/pot was applied alone and in combination with carbofuran at 6 mg/pot. application of p. penetrans along with ...200516628938
studies on the management of root-knot nematode, meloidogyne incognita-wilt fungus, fusarium oxysporum disease complex of green gram, vigna radiata cv ml-1108.studies were conducted under pot conditions to determine the comparative efficacy of carbofuran at 1 mg a.i./kg soil, bavistin at 1 mg a.i./kg soil, neem (azadirachta indica) seed powder at 50 mg/kg soil, green mould (trichoderma harzianum) at 50.0 ml/kg soil, rhizobacteria (pseudomonas fluorescens) at 50.0 ml/kg soil against root-knot nematode, meloidogyne incognita-wilt fungus, fusarium oxysporum disease complex on green gram, vigna radiata cv ml-1108. all the treatments significantly improved ...200516052706
use of trichoderma harzianum and trichoderma viride for the biological control of meloidogyne incognita on tomato.trichoderma harzianum and trichoderma viride were tested for their capacity to reduce the incidence of the root-knot nematode meloidogyne incognita on tomato. in vitro studies demonstrated that all tested isolates were effective in causing nematode mortality compared with the control. trichoderma slightly reduced nematode damage to tomato in vivo. treatment of the soil with the biocontrol agents before transplanting, improved control over treatment directly at transplanting. the trichoderma isol ...200617390844
effects of fly ash, pseudomonas striata and rhizobium on the reproduction of nematode meloidogyne incognita and on the growth and transpiration of pea.glasshouse experiments were conducted twice to assess the ash amendments (0, 20, and 40% with soil), a phosphate solubilizing microorganism pseudomonas striata and a root-nodule bacterium rhizobium sp on the reproduction of root-knot nematode meloidogyne incognita and on the growth and transpiration of pea. amendments of fly ash with soil had no effect on transpiration. however, m. incognita reduced the rate of transpiration from 1st week onward after inoculation while inoculation of rhizobium s ...200516114471
characterization of root-knot nematode resistance in medicago truncatula.root knot (meloidogyne spp.) and cyst (heterodera and globodera spp.) nematodes infect all important crop species, and the annual economic loss due to these pathogens exceeds $90 billion. we screened the worldwide accession collection with the root-knot nematodes meloidogyne incognita, m. arenaria and m. hapla, soybean cyst nematode (scn-heterodera glycines), sugar beet cyst nematode (sbcn-heterodera schachtii) and clover cyst nematode (clcn-heterodera trifolii), revealing resistant and suscepti ...200819259519
reniform in u.s. cotton: when, where, why, and some remedies.the reniform nematode, rotylenchulus reniformis, is an emerging problem in u.s. cotton. the impact of this nematode and the extent to which it has and will continue to spread across the u.s. cotton belt are controversial. long-term changes in cotton production and unique biological attributes of r. reniformis are key factors. expert opinion surveys indicate that r. reniformis has replaced the root-knot nematode (meloidogyne incognita) as the major nematode of cotton in mississippi, louisiana, an ...200717428179
development of controlled release formulations of carbofuran and evaluation of their efficacy against meloidogyne incognita.controlled release (cr) formulations of the insecti-nematicide carbofuran have been prepared using commercially available rosin, sodium carboxymethylcellulose and sodium carboxymethylcellulose with clay (bentonite, kaolinite, and fuller's earth). the kinetics of carbofuran release in soil from the different formulations were studied in comparison with that of the commercially available granules (3g). release from the commercial formulation was faster than with the new cr formulations. addition o ...200616787021
integrated application of some compatible biocontrol agents along with mustard oil seed cake and furadan on meloidogyne incognita infecting tomato plants.experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode meloidogyne incognita infecting tomato under greenhouse condition. bioagents viz., paecilomyces lilacinus and trichoderma viride alone or in combination with mustard cake and furadan promoted plant growth, reduced number of galls/plant, egg masses/root system and eggs/egg mass. the fungal bioagents along with mustard cake and nematicide showed least nematode ...200617048300
feeding and maturation by soybean looper (lepidoptera: noctuidae) larvae on soybean affected by weed, fungus, and nematode pests.feeding and maturation by the soybean looper, pseudoplusia includens (walker) (lepidoptera: noctuidae), were investigated in a 2-yr study on 'davis' soybean, glycine max (l.) merr., grown alone and combined with the weed hemp sesbania, sesbania exaltata (raf.) rybd. ex. a. w. hill, the root-knot nematode, meloidogyne incognita (kofoid & white) chitwood, and the charcoal rot fungus, macrophomina phaseolina (tassi) goid. of the three pests, hemp sesbania had the greatest effects on plant growth an ...200414998122
evaluation of soil biodesinfestation with crop and garden residues in the control of root-knot nematodes populations.fresh crop and garden residues were applied both under laboratory conditions and in commercial greenhouse in order to asses their effect on soil nematodes populations and soil fertility. in the laboratory experiments, dosages of 5 to 20 g of cabbage residues, chicken manure, cabbage residues+chicken manure, grass+chicken manure, as well as leaves and stems of orange tree, pine tree, oleander, olive tree, palm tree and boxwood were mixed with 500 g soil having root-knot nematodes (meloidogyne inc ...200718399508
potentiality of different isolates of wilt fungus fusarium oxysporum collected from rhizosphere of tomato against root-knot nematode meloidogyne incognita.this investigation was undertaken to determine the effect of culture filtrates of different isolates of fusarium oxysporum f. sp. lycopersici on mortality of meloidogyne incognita juveniles and egg hatching. it was observed that different concentrations including standard extract (s.e), 1:10 and 1:100 dilutions of all fungal filtrates inhibited egg hatch when compared with control. minimum mortality and maximum hatching was observed in brt (showing least mortality) isolate of f. oxysporum, while ...200818941992
responses of heterodera glycines and meloidogyne incognita to exogenously applied neuromodulators.biogenic amines regulate important behaviours in nematodes and are associated with pharyngeal activity in plant-parasitic nematodes. a robust behavioural assay based upon nematode body movements was developed to expand the study of these and other neuroregulators in plant-parasitic nematodes. dopamine, octopamine and serotonin each had significant but differing effects on the behaviour of soybean cyst nematode heterodera glycines and root-knot nematode meloidogyne incognita juveniles. body movem ...200718005465
use of crop residues for the control of meloidogyne incognita under laboratory conditions.this laboratory study evaluates the biofumigant effect of different organic materials with the aim of developing non-chemical alternatives for the management of meloidogyne incognita (kofoid & white) chitwood populations. sources of organic material from the production system were selected with the aim of reducing agricultural residue accumulation problems as well as decreasing the costs due to the use of chemical fertilizers and pesticides. the selected materials were residues from pepper, stra ...200616927410
decomposers and root feeders interactively affect plant defence in sinapis alba.aboveground herbivory is well known to change plant growth and defence. in contrast, effects of soil organisms, acting alone or in concert, on allocation patterns are less well understood. we investigated separate and combined effects of the endogeic earthworm species aporrectodea caliginosa and the root feeding nematode species pratylenchus penetrans and meloidogyne incognita on plant responses including growth and defence metabolite concentrations in leaves of white mustard, sinapis alba. soil ...200919252930
effect of application timing and method on efficacy and phytotoxicity of 1,3-d, chloropicrin and metam-sodium combinations in squash plasticulture.metam-sodium, 1,3-dichloropropene (1,3-d) and chloropicrin are widely used soil fumigants. combined application of metam-sodium and 1,3-d + chloropicrin is intended to improve efficacy and broaden spectrum of control, but little is known about the effect on crop safety. this study aimed to evaluate the effects of application timing of fumigant combinations on soilborne pest and disease control (nematodes, soil fungi and weeds) and growth of squash. two separate tests with chisel-injected and dri ...200818181144
colonization by the arbuscular mycorrhizal fungus glomus versiforme induces a defense response against the root-knot nematode meloidogyne incognita in the grapevine (vitis amurensis rupr.), which includes transcriptional activation of the class iii chitinase gene vch3.inoculation of the grapevine (vitis amurensis rupr.) with the arbuscular mycorrhizal (am) fungus glomus versiforme significantly increased resistance against the root-knot nematode (rkn) meloidogyne incognita. studies using relative quantitative reverse transcription-pcr (rqrt-pcr) analysis of grapevine root inoculation with the am fungus revealed an up-regulation of vch3 transcripts. this increase was greater than that observed following infection with rkn. however, inoculation of the mycorrhiz ...200616326755
inter- and intra-specific cuticle variation between amphimictic and parthenogenetic species of root-knot nematode (meloidogyne spp.) as revealed by a bacterial parasite (pasteuria penetrans).specific host-parasite interactions exist between species and strains of plant parasitic root-knot nematodes and the gram-positive bacterial hyperparasite pasteuria penetrans. this bacterium produces endospores that adhere to the cuticle of migrating juveniles, germinate and colonise the developing female within roots. endospore attachment of p. penetrans populations to second-stage juveniles of the root-knot nematode species meloidogyne incognita and meloidogyne hapla showed there were interact ...200818171577
comparative analysis of two 14-3-3 homologues and their expression pattern in the root-knot nematode meloidogyne incognita.14-3-3 proteins are highly conserved ubiquitous proteins found in all eukaryotic organisms. they are involved in various cellular processes including signal transduction, cell-cycle control, apoptosis, stress response and cytoskeleton organisation. we report here the cloning of two genes encoding 14-3-3 isoforms from the plant parasitic root-knot nematode meloidogyne incognita, together with an analysis of their expression. both genes were shown to be transcribed in unhatched second stage larvae ...200415157770
nematode infection and reproduction in transgenic and mutant arabidopsis and tobacco with an altered phenylpropanoid metabolism.transgenic and mutant arabidopsis and tobacco plants with altered phenylpropanoid metabolism were infected with the plant parasitic root knot nematode meloidogyne incognita to assess the effect of the transgene or mutation on nematode infection and reproduction. modifications in the lignin biosynthetic pathway which alter lignin composition in roots affected reproduction. in arabidopsis with increased levels of syringyl lignin, reproduction was lower than in wild-type plants, while in tobacco wi ...200616831845
effects of plant vascular architecture on aboveground-belowground-induced responses to foliar and root herbivores on nicotiana tabacum.herbivores induce systemic changes in plant traits, and the strength of these induced responses is often associated with the degree of vascular connectivity that links damaged and undamaged plant tissues. although this phenomenon is known to occur aboveground in leaves, it is unknown whether or not leaf-root induction similarly follows the vascular architecture of plants. to test for this possibility, we manipulated foliar and root herbivory on tobacco (nicotiana tabacum) by the leaf-chewing ins ...200818810552
gastrodia anti-fungal protein from the orchid gastrodia elata confers disease resistance to root pathogens in transgenic tobacco.diseases of agricultural crops are caused by pathogens from several higher-order phylogenetic lineages including fungi, straminipila, eubacteria, and metazoa. these pathogens are commonly managed with pesticides due to the lack of broad-spectrum host resistance. gastrodia anti-fungal protein (gafp; gastrodianin) may provide a level of broad-spectrum resistance due to its documented anti-fungal activity in vitro and structural similarity to insecticidal lectins. we transformed tobacco (nicotiana ...200616858580
direct identification of the meloidogyne incognita secretome reveals proteins with host cell reprogramming potential.the root knot nematode, meloidogyne incognita, is an obligate parasite that causes significant damage to a broad range of host plants. infection is associated with secretion of proteins surrounded by proliferating cells. many parasites are known to secrete effectors that interfere with plant innate immunity, enabling infection to occur; they can also release pathogen-associated molecular patterns (pamps, e.g., flagellin) that trigger basal immunity through the nematode stylet into the plant cell ...200818974830
greenhouse studies on the effect of marigolds (tagetes spp.) on four meloidogyne species.the effects of preplanted marigold on tomato root galling and multiplication of meloidogyne incognita, m. javanica, m. arenaria, and m. hapla were studied. marigold cultivars of tagetes patula, t. erecta, t. signata, and a tagetes hybrid all reduced galling and numbers of second-stage juveniles in subsequent tomato compared to the tomato-tomato control. all four meloidogyne spp. reproduced on t. signata 'tangerine gem'. several cultivars of t. patula and t. erecta suppressed galling and reproduc ...199919270876
the future of nematode management in cotton.the importance of plant-parasitic nematodes as yield-limiting pathogens of cotton has received increased recognition and attention in the united states in the recent past. this paper summarizes the remarks made during a symposium of the same title that was held in july 2007 at the joint meeting of the society of nematologists and the american phytopathological society in san diego, california. although several cultural practices, including crop rotation, can be effective in suppressing the popul ...200719259500
detection and investigation of soil biological activity against meloidogyne incognita.greenhouse experiments with two susceptible hosts of meloidogyne incognita, a dwarf tomato and wheat, led to the identification of a soil in which the root-knot nematode population was reduced 5- to 16-fold compared to identical but pasteurized soil two months after infestation with 280 m. incognita j2/100 cm(3) soil. this suppressive soil was subjected to various temperature, fumigation and dilution treatments, planted with tomato, and infested with 1,000 eggs of m. incognita/100 cm(3) soil. ei ...200819259527
survey of crop losses in response to phytoparasitic nematodes in the united states for 1994.previous reports of crop losses to plant-parasitic nematodes have relied on published results of survey data based on certain commodities, including tobacco, peanuts, cotton, and soybean. reports on crop-loss assessment by land-grant universities and many commodity groups generally are no longer available, with the exception of the university of georgia, the beltwide cotton conference, and selected groups concerned with soybean. the society of nematologists extension committee contacted extensio ...199919270925
fosthiazate controls meloidogyne arenaria and m. incognita in flue-cured tobacco.the nematicide fosthiazate was evaluated over a 3-year period for management of meloidogyne incognita race 3 (site 1) and m. arenaria race 2 (site 2) in flue-cured tobacco. fosthiazate was applied broadcast and incorporated at rates ranging from 22 to 88 g a.i./100 m(2), and compared with the nematicides fenamiphos (67 g a.i./100 m(2)), 1,3-d (56.1 l/ha, 670 ml/100-m row), and an untreated control. root-gall indices and leaf yields were averaged over the 3-year period. root galling was negativel ...199919270938
effect of temperature on suppression of meloidogyne incognita by tagetes cultivars.the suppression of meloidogyne incognita by marigolds differed among six marigold cultivars and five soil temperatures. tagetes signata (syn. t. tenuifolia) cv. tangerine gem and the tagetes hybrid polynema allowed reproduction and root galling when grown at 30 degrees c, and should not be used for control of m. incognita at temperatures close to 30 degrees c. tagetes patula cultivars single gold and tangerine and t. erecta flor de muerto, when grown within a 20-30 degrees c soil temperature ran ...199919270940
nematicidal prenylated flavanones from phyllanthus niruri.two prenylated flavanones have been isolated from the hexane extract of phyllanthus niruri plant. the structure of these flavanones were established as 8-(3-methyl-but-2-enyl)-2-phenyl chroman-4-one (1) and 2-(4-hydroxyphenyl)-8-(3-methyl-but-2-enyl)-chroman-4-one (2) on the basis of spectral analysis. these were evaluated for nematicidal activity against root-knot, meloidogyne incognita, and reniform, rotylenchulus reniformis, nematodes. compound 2 exhibited nematicidal activity at par with the ...200817904597
molecular detection of nematicidal crystalliferous bacillus thuringiensis strains of iran and evaluation of their toxicity on free-living and plant-parasitic nematodes.the characterization of nematode-effective strains and cry genes in the iranian bacillus thuringiensis (bt) collection (70 isolates) is presented. characterization was based on pcr analysis using 12 specific primers for cry5, cry6, cry12, cry13, cry14, and cry21 genes encoding proteins active against nematodes, crystal morphology, and protein band patterns as well as their nematicidal activity on root-knot nematode (meloidogyne incognita) and two free-living nematodes (chiloplacus tenuis and acr ...200818923549
plantago lanceolata and plantago rugelii extracts are toxic to meloidogyne incognita but not to certain microbes.extracts from the plants plantago lanceolata and p. rugelii were evaluated for toxicity to the root-knot nematode meloidogyne incognita, the beneficial microbes enterobacter cloacae, pseudomonas fluorescens and trichoderma virens, and the plant-pathogenic fungi fusarium oxysporum f. sp. gladioli, phytophthora capsici, pythium ultimum, and rhizoctonia solani. wild plants were collected, roots were excised from shoots, and the plant parts were dried and ground to a powder. one set of extracts (10% ...200619259537
expression and regulation of the arabidopsis thaliana cel1 endo 1,4 beta glucanase gene during compatible plant-nematode interactions.the root-knot nematode meloidogyne incognita is an obligate endoparasite of plant roots and stimulates elaborate modifications of selected root vascular cells to form giant cells for feeding. an arabidopsis thaliana endoglucanase (atcel1) promoter is activated in giant cells that were formed in atcel1::uida transgenic tobacco and arabidopsis plants. activity of the full-length atcel1 promoter was detected in root and shoot elongation zones and in the lateral root primordia. different 5' and inte ...200619259541
endophytic colonization of plants by the biocontrol agent rhizobium etli g12 in relation to meloidogyne incognita infection.abstract the external and internal colonization of potato and arabidopsis roots by the biocontrol strain rhizobium etli g12 containing a plasmidborne trp promoter green fluorescent protein transcriptional fusion, pgt-trp, was studied in the presence and absence of the root-knot nematode meloidogyne incognita. plant colonization behavior and biocontrol potential of the marked strain g12(pgt-trp) was not altered compared with the parental strain. plasmid pgt-trp was stable for more than 80 generat ...200118943855
inoculum densities of fusarium oxysporum f. sp. vasinfectum and meloidogyne incognita in relation to the development of fusarium wilt and the phenology of cotton plants (gossypium hirsutum).abstract development of fusarium wilt in upland cotton (gossypium hirsutum) usually requires infections of plants by both meloidogyne incognita and fusarium oxysporum f. sp. vasinfectum. in this study, the soil densities of m. incognita and f. oxysporum f. sp. vasinfectum and the incidence of fusarium wilt in three field sites were determined in 1982-1984. multiple regression analysis of percent incidence of fusarium wilt symptoms on population densities of m. incognita and f. oxysporum f. sp. v ...199718945178
reproduction of belonolaimus longicaudatus, meloidogyne javanica, paratrichodorus minor, and pratylenchus brachyurus on pearl millet (pennisetum glaucum).pearl millet (pennisetum glaucum) has potential as a grain crop for dryland crop production in the southeastern united states. whether or not pearl millet will be compatible in rotation with cotton (gossypium hirsutum), corn (zea mays), and peanut (arachis hypogaea) will depend, in part, on its host status for important plant-parasitic nematodes of these crops. the pearl millet hybrid 'tifgrain 102' is resistant to both meloidogyne incognita race 3 and m. arenaria race 1; however, its host statu ...200519262863
factors affecting the suppression of heterodera glycines by n-viro soil.previous laboratory research demonstrated that n-viro soil (nvs), an alkaline-stabilized municipal biosolid, suppressed plant-parasitic nematodes. this study continued to explore the use of nvs as a nematode management tool specifically addressing factors that could influence its use. n-viro soil from different locations, the components of nvs (de-watered biosolids and fly ash admixtures), and sterilized nvs were applied to sand microcosms to determine effects on nematode survival sand solution ...200519262864
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