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induction of tolerance to root-knot nematode by oxycom.oxycom applications increased plant growth and population levels of meloidogyne incognita on susceptible tomato. a single oxycom drench at 2,500 ppm applied 7 days prior to inoculation with m. incognita provided remediation of plant growth measured 63 days later. this occurred without reducing nematode population levels. follow-up drenches at 2,500 ppm at 10-day intervals stunted shoots and roots (p = 0.05). the same application rates at 20-day intervals did not reduce plant growth. plants recei ...200319262766
effect of crotalaria juncea amendment on nematode communities in soil with different agricultural histories.effect of sunn hemp (crotalaria juncea) hay amendment on nematode community structure in the soil surrounding roots of yellow squash (cucurbita pepo) infected with root-knot nematodes was examined in two greenhouse experiments. soils were from field plots treated long-term (lt) with yard-waste compost or no yard-waste compost in lt experiment, and from a short-term (st) agricultural site in st experiment. soils collected were either amended or not amended with c. juncea hay. nematode communities ...200319262764
pr proteins in plants infested with the root-knot nematode meloidogyne incognita (kofoid et white, 1919) chitwood 1949. 201612918384
a profile of putative parasitism genes expressed in the esophageal gland cells of the root-knot nematode meloidogyne incognita.identifying parasitism genes encoding proteins secreted from a nematode's esophageal gland cells and injected through its stylet into plant tissue is the key to understanding the molecular basis of nematode parasitism of plants. meloidogyne incognita parasitism genes were cloned by microaspirating the cytoplasm from the esophageal gland cells of different parasitic stages to provide mrna to create a gland cell-specific cdna library by long-distance reverse-transcriptase polymerase chain reaction ...200312744507
management of root-knot nematode in tomato lycopersicon esculentum, mill, with biogas slurry.the effect of biogas slurry application on the severity of root-knot nematode, meloidogyne incognita, attack on tomato cv. co-1, was tested in the green house with two levels of biogas slurry: 5% and 10% (w/w) added to soil. both the number (3 fruits/plant) and fruit yield (35.2 g/plant) of tomato increased significantly with 10% (w/w) biogas slurry. the plants amended with biogas slurry put up more vegetative growth and tended to flower and fruit much earlier than did those of the control. the ...200312699936
efficacy of the liquid formulation of some nematicides.bunches of 25 g of tomato galled roots containing ca. 270 eggs and juveniles/g of meloidogyne incognita were buried on 29 september 2001 in gauze bags at the depth of 15, 30 and 45 cm in a sandy loam. the liquid formulation of the nematicides 1,3 dichloropropene (at the rate of 100, 200 and 300 l/ha), metam sodium (at the rate of 500, 1000, and 1500 l/ha), oxamyl (at the rate of 50, 100 and 150 l/ha) and fenamiphos (at the rate of 30, 60, and 90 l/ha) were then applied in 10, 20 or 40 l/m2 of wa ...200212696439
relationship of aerial broad band reflectance to meloidogyne incognita density in cotton.aerial images were obtained on 22 july 1999 and 4 august 2000 from five cotton sites infested with meloidogyne incognita. images contained three broad bands representing the green (500-600 nm), red (600-700 nm), and near-infrared (700-900 nm) spectrum. soil samples were collected and assayed for nematodes in the fall at these sites. sampling locations were identified from images, by locating the coordinates of a wide range of light intensity (measured as a digital number) for each single band, a ...200319265974
arabidopsis thaliana mutants with an altered susceptibility to the root-knot nematode meloidogyne incognita.sedentary endoparasitic nematodes of plants are obligate parasites of roots in which they complete their sophisticated life cycle. to study the plant/root-knot nematode interaction, a screening was performed for mutants of arabidopsis thaliana that were less susceptible to nematode infection. ethyl methanesulfonate-mutagenized a. thaliana m2 seeds (13,000) were germinated and the seedlings were screened in vitro for nematode susceptibility. another 5,000 plants were screened in a sand mixture un ...200212491969
host plant resistance as an alternative to methyl bromide for managing meloidogyne incognita in pepper.pre-plant soil fumigation with methyl bromide and host resistance were compared for managing the southern root-knot nematode (meloidogyne incognita) in pepper. three pepper cultivars (carolina cayenne, keystone resistant giant, and california wonder) that differed in resistance to m. incognita were grown in field plots that had been fumigated with methyl bromide (98% chbr : 2% cclno [w/w]) before planting or left untreated. carolina cayenne is a well-adapted cayenne-type pepper that is highly re ...200219265959
non-traditional legumes as potential soil amendments for nematode control.dried ground plant tissues from 20 leguminous species were mixed with meloidogyne incognita-infested soil at 1, 2 or 2.5, and 5% (w/w) and incubated for 1 week at room temperature (21 to 27 degrees c). tomato ('rutgers') seedlings were transplanted into infested soil to determine nematode viability. most tissues reduced gall numbers below the non-amended controls. the tissue amendments that were most effective include: canavalia ensiformis, crotalaria retusa, indigofera hirsuta, i. nummularifoli ...200219265956
red food coloring stain: new, safer procedures for staining nematodes in roots and egg masses on root surfaces.acid fuchsin and phloxine b are commonly used to stain plant-parasitic nematodes in roots and egg masses on root surfaces, respectively. both stains can be harmful to both the user and the environment and require costly waste disposal procedures. we developed safer methods to replace both stains using mccormick schilling red food color. eggs, juveniles, and adults of meloidogyne incognita stained in roots with red food color were equally as visible as those stained with acid fuchsin. egg masses ...200219265929
effects of site-specific application of aldicarb on cotton in a meloidogyne incognita-infested field.cotton farmers in missouri commonly apply a single rate of aldicarb throughout the field at planting to protect their crop from meloidogyne incognita, even though these nematodes are spatially aggregated. our purpose was to determine the effect of site-specific application of aldicarb on cotton production in a field infested with these nematodes in 1997 and 1998. cotton yields were collected from sites not treated with aldicarb (control), sites receiving aldicarb at the standard recommended rate ...200219265917
direct identification of stylet secreted proteins from root-knot nematodes by a proteomic approach.the stylet secretions produced by plant parasitic root-knot nematodes are thought to be pathogenicity factors involved in the invasion of the root tissue and in the induction and maintenance of feeding cells. a new procedure was established that allowed the direct qualitative analysis of proteins secreted by meloidogyne incognita infective juveniles. purified proteins whose isoelectric point (pi) ranged from 5.0 to 7.5 were separated by two-dimensional (2d) electrophoresis and the seven most abu ...200212034454
biologically active secondary metabolites from the ascomycete a111-95. 1. production, isolation and biological activities.eight secondary metabolites were isolated from submerged cultures of the ascomycete a111-95 during a search for new nematicidal metabolites. (-)-galiellalactone (7) and compound 2 are metabolites previously obtained from cultures of galiella rufa while the compounds 1, 3, 4, 5, 6 and 8 (3 and 4 were obtained as an unseparable mixture), were isolated as natural products for the first time. compound 2, pregaliellalactone (5) and the mixture of 3 and 4 showed nematicidal activities towards caenorha ...200211918063
[investigation on root-knot diseases of medicinal plants in yunnan].during 1994-1997, the damage levels about root-knot diseases on 52 medicinal plants were investigated and analyzed. 185 samples were collected from more than 20 counties or cities in yunnan province. the results showed that 76 specimens were infected by root-knot nematode, which are meloidogyne incognita (kofoid and white 1919, chitwood 1949), m. javanice (trenb 1855, chitwood 1949), m. arenaria (neal 1889, chitwood 1949) and m. halpa (chitwood 1949). they infected 21 medicinal plants. the paper ...200111917839
efficacy of 1,3-dichloropropene in soil amended with compost and unamended soil.1,3-dichloropropene (1,3-d) is a likely alternative soil fumigant for methyl bromide. the objective was to determine root-knot nematode, meloidogyne incognita, survival in microplots after exposure to 1,3-d for various periods of time in soil that have previously been amended with compost. the treatments were 1,3-d applied broadcast at 112 liters/ha and untreated controls in both compost-amended and unamended soil. soil samples were collected from each microplot at 6, 24, 48, 72, and 96 hours af ...200119265889
pesticidal properties of parthenin (from parthenium hysterophorus) and related compounds.eleven sesquiterpene lactone derivatives of parthenin (1), obtained from wild feverfew, parthenium hysterophorus, were prepared by chemical and photochemical transformations. the compounds tested were a pyrazoline adduct (2) of parthenin, its cyclopropyl (3) and propenyl (4) derivatives, anhydroparthenin (5), a dihydro-deoxygenated product (6), a formate (7) and its corresponding alcohol (8) and acetate (9), a rearranged product (10), lactone (11) and hemiacetal (12). all these derivatives, alon ...200111455638
genes induced during early response to meloidogyne incognita in roots of resistant and susceptible alfalfa cultivars.a cdna library made to rna from roots of meloidogyne incognita (root-knot nematode) susceptible alfalfa cv. lahontan seedlings 72 h after root-knot nematode inoculation was differentially screened with cdna made from uninoculated control and m. incognita infested (72 h) root rna. of the six cdnas isolated, the deduced amino acid sequences of four showed significant homology to sequences present in the databank, while two were pioneer sequences. the four cdnas with matches to known sequences incl ...200111448760
resistance as a tactic for management of meloidogyne incognita on cotton in north carolina.selected cotton cultivars were evaluated for resistance to the southern root-knot nematode, meloidogyne incognita, in greenhouse and field experiments. cotton cultivars la 887, auburn 634, and nemx cotton were highly resistant to three north carolina populations of root-knot nematode in greenhouse experiments compared to susceptible cultivars. the relative susceptibility of cultivars tested in the greenhouse from most to least susceptible were deltapine 16 > deltapine 50 > la 887 or nemx > aubur ...200119266008
arabidopsis thaliana genes expressed in the early compatible interaction with root-knot nematodes.in the compatible interaction between arabidopsis thaliana and the endoparasitic nematode meloidogyne incognita, galls are formed on the roots of the host plant. differential display was used to identify alterations of gene expression in young a. thaliana root galls caused by m. incognita. six genes were confirmed as plant genes by dna gel blot hybridizations. significant homology was found with a trypsin inhibitor, peroxidase, mitochondrial uncoupling protein, endomembrane protein, 20s proteaso ...200111277426
[modulation of plant resistance to diseases by water-soluble chitosan].low-molecular-weight water-soluble chitosan with a molecular weight of 5 kda obtained after enzymatic hydrolysis of native crab chitosan was shown to display an elicitor activity by inducing the local and systemic resistance of solanumi tuberosum potato and lycopesicon esculentum tomato to phytophthora infestans and nematodes, respectively. chitosan induced the accumulation of phytoalexins in tissues of host plants, decreased the total content and changed the composition of free sterols producin ...201311234398
molecular cloning of a cdna encoding an amphid-secreted putative avirulence protein from the root-knot nematode meloidogyne incognita.amplified fragment length polymorphism fingerprinting of three pairs of meloidogyne incognita near-isogenic lines (nils) was used to identify markers differential between nematode genotypes avirulent or virulent against the tomato mi resistance gene. one of these sequences, present only in the avirulent lines, was used as a probe to screen a cdna library from second-stage juveniles (j2s) and allowed cloning of a cdna encoding a secretory protein. the putative full-length cdna, named map-1, encod ...200111194874
cdna cloning and expression analysis of a calponin gene from the plant-parasitic nematode meloidogyne incognita. 200111166397
survey of meloidogyne incognita and thielaviopsis basicola: their impact on cotton fruiting and producers' management choices in infested fields.a survey of 100 cotton fields selected randomly in 1995 and 1996 was conducted in the high plains of texas to determine the incidence and potential severity of meloidogyne incognita and thielaviopsis basicola. information was obtained from producers for each field on their nematicide application rates and fungicide seed treatments. the percent of squares and bolls set was evaluated for 20 plants in each field during late july 1995 and early august 1996. thielaviopsis basicola was identified in 5 ...200019271012
root galling and reproduction of meloidogyne incognita isolates from texas on resistant cotton genotypes.several cotton genotypes with resistance to meloidogyne incognita have been released in recent years. to estimate the durability of this resistance, galling severity on these resistant genotypes by m. incognita was measured. nematode isolates (115 total) were collected from cotton fields in 14 texas counties in august and september 1996 and 1997. four additional isolates from maryland, mississippi, and north carolina were also tested. the isolates were evaluated in 12 greenhouse experiments for ...200019271003
effects of meloidogyne incognita on growth and storage-root formation of cassava (manihot esculenta).two-node cuttings of cassava cultivar ss4 were inoculated with 1,000 infective juveniles of meloidogyne incognita at 1, 14, 40, 70, 88, and 127 days after planting (dap). plant growth and root damage were assessed at 150 dap. meloidogyne incognita significantly reduced the number of storageroots formed in plants inoculated at 14, 40, 70, and 88 dap and the total weight of storage-roots in plants inoculated at 1, 14, 40, 70, and 88 dap, compared to uninoculated plants. individual storage-root wei ...200019270997
heat stability of resistance to meloidogyne incognita in scotch bonnet peppers ( capsicum chinense jacq.).stability of resistance to meloidogyne incognita (kofoid &white) chitwood was determined in pepper (capsicum chinense jacq. and c. annuum l.) at 24, 28, and 32 degrees c. reactions of the c. annuum cultivars charleston belle and keystone resistant giant and the c. chinense cultigens pa-426 and pa-350 to m. incognita were compared. charleston belle is homozygous for the n gene that confers resistance to m. incognita in c. annuum, and keystone resistant giant is the susceptible recurrent parent of ...200019270989
using microwave irradiation to improve preservation of female nematodes and gall tissues for tem observations.microwave irradiation of glutaraldehyde-immersed samples was evaluated for the chemical fixation of 3-week-old galls that resulted from the infection of tomato roots (lycopersicon esculentum) by a root-knot nematode, meloidogyne incognita. observation by transmission electron microscopy indicated that the best results were obtained when vials containing the intact galls were immersed in buffered glutaraldehyde and irradiated for 10 seconds then allowed to cool for 30 seconds; this procedure was ...200019270984
variability in time and space of meloidogyne incognita fall population density in cotton fields.three cotton fields infested with meloidogyne incognita were intensively sampled in the fall for 3 years (1996 to 1998) to determine if intensive sampling for m. incognita, for which spatial location is important, was necessary every year in a continuous cotton system. two composite soil samples (20 cores each), taken over an area covering one-third of the field length and two rows wide, were averaged to represent that area (row-location combination). each field (except one) had 24 areas assayed ...200019270975
nematicidal constituents of the aerial parts of lantana camara.two new constituents, lantanoside (1) and lantanone (2), and the known compounds linaroside (3) and camarinic acid (4) were isolated from the aerial parts of lantana camara. compounds 1, 3, and 4 were tested for nematicidal activity against root-knot nematode meloidogyne incognita and showed 90, 85, and 100% mortality, respectively, at 1.0% concentration. the results were comparable to those obtained with the conventional nematicide furadan (100% mortality at 1.0% concentration). structures of t ...200010869197
origin of a meloidogyne incognita surface coat antigen.the surface coat (sc) of plant nematodes is thought to originate either from the living hypodermis or from secretory glands associated with the excretory system or nervous system. in this study, we investigated the origin of the sc of meloidogyne incognita by immunolocalization with a monoclonal antibody raised against the surface coat of the preparasitic juveniles (j2). under the electron microscope, strong labeling was found on the cuticular surface and in the rectal dilation of the j2, while ...200019270963
effect of mulch surface color on root-knot of tomato grown in simulated planting beds.the effect of different-colored polyethylene mulches on quantity and spectra of reflected light, plant morphology, and root-knot disease was studied in tomato (lycopersicon esculentum) grown in simulated planting beds. tomato plants were inoculated with meloidogyne incognita at initial populations (pi) of 0, 1,000, 10,000, or 50,000 eggs/plant, and grown in a greenhouse for 50 days over white, red, or black mulch. soil temperature was kept constant among the mulch treatments by placing an insula ...200019270954
comparison of variable and single-rate applications of aldicarb on cotton yield in fields infested with meloidogyne incognita.variable-rate applications of the nematicide aldicarb were compared to producer standard rates in eight field tests over 3 years. test areas (308 to 1,015 m long) were divided into eight or five blocks. each block contained two plots with a variable-rate treatment (vrt) of aldicarb and a producer standard treatment (pst) of aldicarb. each vrt plot was divided into three subunits and intensively sampled for meloidogyne incognita in either the fall or spring before planting. rates of aldicarb were ...199919270939
evaluation of dry ice as a potential cryonematicide for meloidogyne incognita in soil.solid co (dry ice) was added to pots containing soil that was infested either with eggs of the root-knot nematode, meloidogyne incognita, or with tomato (lycopersicon esculentum 'rutgers') root fragments that were infected with various stages of the nematode. two hours after dry ice was added, thermocouples in the soil recorded temperatures ranging from -15 degrees c to -59 degrees c. one day after treatment with the dry ice, the temperature of the soil was allowed to equilibrate with that of th ...199919270918
isolation of a cdna encoding a beta-1,4-endoglucanase in the root-knot nematode meloidogyne incognita and expression analysis during plant parasitism.a beta-1,4-endoglucanase encoding cdna (egases, e.c. 3.2.1.4), named mi-eng-1, was cloned from meloidogyne incognita second-stage juveniles (j2). the deduced amino acid sequence contains a catalytic domain and a cellulose-binding domain separated by a linker. in m. incognita, the gene is transcribed in the migratory j2, in males, and in the sedentary adult females. in pre-parasitic j2, endoglucanase transcripts are located in the cytoplasm of the subventral esophageal glands. the presence of bet ...199910478479
carbon partitioning in soybean infected with meloidogyne incognita and m. javanica.seven-day-old seedlings of two cultivars (cristalina and ufv itm1) of glycine max were inoculated with 0, 3,000, 9,000, or 27,000 eggs of meloidogyne incognita race 3 or m. javanica and maintained in a greenhouse. thirty days later, plants were exposed to (1)co for 4 hours. twenty hours after (1)co exposure, the root fresh weight, leaf dry weight, nematode eggs per gram of root, total and specific radioactivity of carbohydrates in roots, and root carbohydrate content were evaluated. meloidogyne ...199919270907
reproduction and development of meloidogyne incognita and m. javanica on guardian peach rootstock.guardian peach rootstock was evaluated for susceptibility to meloidogyne incognita race 3 (georgia-peach isolate) and m. javanica in the greenhouse. both commercial guardian seed sources produced plants that were poor hosts of m. incognita and m. javanica. reproduction as measured by number of egg masses and eggs per plant, eggs per egg mass, and eggs per gram of root were a better measure of host resistance than number of root galls per plant. penetration, development, and reproduction of m. in ...199919270905
meloidogyne incognita surface antigen epitopes in infected arabidopsis roots.surface-coat epitopes of meloidogyne incognita were detected in root tissues of arabidopsis thaliana during migration and feeding site formation. a whole-mount root technique was used for immunolocalization of surface coat epitopes in a. thaliana, with the aid of a monoclonal antibody raised specifically against the outer surface of infective juveniles of m. incognita. the antibody, which was meloidogyne-specific, recognized a fucosyl-bearing glycoprotein in the surface coat. during migration in ...199919270892
effects of a resistant corn hybrid and fenamiphos on meloidogyne incognita in a corn-squash rotation.the efficacy of a double-cross corn (zea mays) hybrid (old raccoon selection x t216) x (tebeau selection x mp 307) resistant to meloidogyne incognita as a rotational crop, and fenamiphos treatment for management of root-knot nematode (m. incognita race 1) in squash (cucurbita pepo var. melopepo) was evaluated in field tests during 1996 and 1997. numbers of m. incognita in the soil and root-gall indices were lower on the resistant hybrid than on a commercial cultivar dekalb dk-683. treatment mean ...199919270888
rhizosphere colonization and control of meloidogyne spp. by nematode-trapping fungi.the ability of nematode-trapping fungi to colonize the rhizosphere of crop plants has been suggested to be an important factor in biological control of root-infecting nematodes. in this study, rhizosphere colonization was evaluated for 38 isolates of nematode-trapping fungi representing 11 species. in an initial screen, arthrobotrys dactyloides, a. superba, and monacrosporium ellipsosporum were most frequently detected in the tomato rhizosphere. in subsequent pot experiments these fungi and the ...199919270886
molecular cloning of an acetylcholinesterase gene from the plant parasitic nematodes, meloidogyne incognita and meloidogyne javanica.a gene encoding a protein with strong homology with caenorhabditis elegans and c. briggsae acetylcholinesterase ace-1 was cloned from meloidogyne incognita and m. javanica pre-parasitic juveniles. both cdnas have an orf of 1968 bp for a deduced translation product of 656 amino acid residues. the key residues essential to acetylcholinesterase (ache) structure and function are conserved in both sequences. m. incognita and m. javanica ache share a homology of 98.8% at the amino acid level and 97% a ...199910340488
isolation of the lemmi9 gene and promoter analysis during a compatible plant-nematode interaction.plant-endoparasitic root-knot nematodes feed on specialized giant cells that they induce in the vascular cylinder of susceptible plants. although it has been established that a number of plant genes change their expression pattern during giant cell differentiation, virtually no data are available about the mechanisms involved in that change. one possibility is differential promoter recognition by the transcription factor(s) responsible for the expression of specific genes. we have isolated and c ...199910226377
the tomato mi-1 gene confers resistance to both root-knot nematodes and potato aphids.mi-1, a lycopersicon peruvianum gene conferring resistance to the agricultural pests, root-knot nematodes, and introgressed into tomato, has been cloned using a selective restriction fragment amplification based strategy. complementation analysis of a susceptible tomato line with a 100 kb cosmid array yielded a single cosmid clone capable of conferring resistance both to the root-knot nematode meloidogyne incognita and to an unrelated pathogen, the potato aphid macrosiphum euphorbiae. this resis ...19989853621
rpe, a plant gene involved in early developmental steps of nematode feeding cells.sedentary plant-parasitic nematodes are able to induce the redifferentiation of root cells into multinucleate nematode feeding sites (nfss). we have isolated by promoter trapping an arabidopsis thaliana gene that is essential for the early steps of nfs formation induced by the root-knot nematode meloidogyne incognita. its pattern of expression is similar to that of key regulators of the cell cycle, but it is not observed with the cyst nematode. later in nfs development, this gene is induced by b ...19989843485
responses of cotton yield and meloidogyne incognita soil populations to soil applications of aldicarb and 1,3-d in florida.in four tests conducted in loamy-sand soils in northern florida, cotton lint yield increased and post-harvest soil populations of meloidogyne incognita were more effectively suppressed by 1,3-dichloropropene (1,3-d) than aldicarb when both nematicides were evaluated over a range of recommended rates. significant positive relationships existed between lint yield and rates of 1,3-d in three tests, whereas only one significant positive relationship occurred between lint yield and aldicarb rates. yi ...199819274259
response of sesamum indicum and s. radiatum accessions to root-knot nematode, meloidogyne incognita.twenty sesame indicum and four s. radiatum accessions in the usda plant introduction collection were evaluated for reaction to the root-knot nematode, meloidogyne incognita race 3, at two initial egg densities under greenhouse conditions. all sesame accessions produced considerably fewer root galls than the tomato cultivar rutgers. gall numbers varied slightly among accessions at the higher infestation density with even less variation at the lower density. egg mass indices indicated little repro ...199819274255
interaction between meloidogyne incognita and thielaviopsis basicola on cotton (gossypium hirsutum).the effects of meloidogyne incognita and thielaviopsis basicola on the growth of cotton (gossypium hirsutum) and the effects of t. basicola on m. incognita populations were evaluated in a 2-year study. microplots were infested with m. incognita, t. basicola, or a combination of m. incognita and t. basicola. uninfested plots served as controls both years. seedling survival was decreased by the m. incognita + t. basicola treatment compared to the control. meloidogyne incognita alone and m. incogni ...199819274234
identification of a meloidogyne incognita cuticle collagen gene and characterization of the developmental expression of three collagen genes in parasitic stages. 19989662034
reducing meloidogyne incognita injury to cucumber in a tomato-cucumber double-cropping system.the effects of a root-knot nematode-resistant tomato cultivar and application of the nematicide ethoprop on root-knot nematode injury to cucumber were compared in a tomato-cucumber double-cropping system. a root-knot nematode-resistant tomato cultivar, celebrity, and a susceptible cultivar, heatwave, were grown in rotation with cucumber in 1995 and 1996. celebrity suppressed populations of meloidogyne incognita in the soil and resulted in a low root-gall rating on the subsequent cucumber crop. n ...199819274214
potential of foliar, dip, and injection applications of avermectins for control of plant-parasitic nematodes.studies were conducted to determine the potential of two avermectin compounds, abamectin and emamectin benzoate, for controlling plant-parasitic nematodes when applied by three methods: foliar spray, root dip, and pseudostem injection. experiments were conducted against meloidogyne incognita on tomato, m. javanica on banana, and radopholus similis on banana. foliar applications of both avermectins to banana and tomato were not effective for controlling any of the nematodes evaluated. root dips o ...199819274200
degradation of fenamiphos in agricultural production soil.nematicides are used to control a wide variety of nematodes on many crops; unfortunately, oftentimes the control they provide is erratic. this erratic behavior is not always predictable and has been associated with chemical, physical, and biological degradation of nematicides. their accelerated degradation is an agricultural problem that has been observed in crop monocultures and in other crop production systems where a biodegradable compound is repeatedly applied to the same soil. the problem c ...199819274197
effect of compost and maize cultivars on plant-parasitic nematodes.effects of yard waste compost and maize (zea mays) cultivar on population densities of plant-parasitic nematodes were examined in four experiments in north florida. in one experiment, eight maize cultivars were evaluated; the other three experiments involved split-plot designs with compost treatments as main plots and maize cultivars as subplots. the three compost treatments used in these experiments were: 269 mt/ha of a yard-waste compost applied to the soil surface as a mulch, 269 mt/ha of com ...199719274277
impact of meloidogyne incognita on the incidence of peach tree short life in the presence of criconemella xenoplax.the relationship between cricenemella xenoplax alone and in combination with meloidogyne incognitaon the incidence of peach tree short life disease was studied in field microplots during 1989-96. the presence of m. incognita suppressed the population density of c. xenoplax on lovell peach. tree trunk diameter was significantly reduced in the presence of both nematode species prior to 1993. soil ph was lowest in the co-infection treatment as compared with the uninoculated control on three of the ...199719274276
colored mulches affect yield of fresh-market tomato infected with meloidogyne incognita.the effects of different-colored polyethylene mulches on the quantity and spectra of reflected light, earliness of fruit set, fruit yield and quality, and root-knot disease were studied in field-grown, staked tomato (lycopersicon esculentum). white mulch reflected more photosynthetic light and a lower far-red-to-red ratio than red mulch, whereas black mulch reflected less than 5 percent of any color. soil temperatures and fruit yields were recorded for tomato plants inoculated with meloidogyne i ...199719274191
evaluation of nemx, a new cultivar of cotton with high resistance to meloidogyne incognita.the level of resistance to root-knot nematode, meloidogyne incognita, in nemx, a new cultivar of the acala-type upland cotton, was evaluated in relation to four resistant breeding lines (n6072, n8577, n901, and n903) and four susceptible cultivars (maxxa, sj2, royale, and prema). in growth pouch tests, an average of only 4 nematode egg masses was produced on roots of nemx or the resistant lines, compared to a significantly higher average of 21 on the susceptible cultivars. in pot tests, the nema ...199719274190
activity and differential induction of chitinase isozymes in soybean cultivars resistant or susceptible to root-knot nematodes.host physiological events in relation to infestation by parasitic nematodes are not well documented. soybean plant responses to meloidogyne incognita infestation were compared to resistant (bryan) and susceptible (brim) cultivars at 0, 1, 3, 10, 20, and 34 days after infestation (dai). the resistant cultivar had higher chitinase activity than the susceptible cultivar at every sample time beginning at 3 dai. results from isoelectric focusing gel electrophoresis analyses indicated that three acidi ...199719274189
meloidogyne incognita inoculum source affects host suitability and growth of yellow nutsedge and chile pepper.meloidogyne incognita (mi) reproduction and host plant responses in chile pepper (capsicum annuum) and yellow nutsedge (cyperus esculentus = yns) to three sources of inoculum obtained by rearing a single mi population on chile, yns, and tomato were evaluated in two factorial greenhouse experiments. the interactive effects of mi inoculum source and crop-weed competition were determined. in the absence of yns competition, chile growth was reduced less by mi inoculum from chile than by inoculum fro ...199719274174
identification and characterization of the meloidogyne incognita col1 cuticle collagen gene. 19969010847
effect of yard waste compost on nematode densities and maize yield.the effects of a yard waste compost on densities of plant-parasitic nematodes and forage yield of maize (zea mays) were determined over three seasons in two sites in north florida. in each test, the experimental design was a randomized complete block with five replications and three treatments: 269 mt/ha of a yard waste compost c:n ratio = 35:1 to 46:1) applied to the soil surface as a mulch, 269 mt/ha of compost incorporated into the soil, and an unamended control. of the nematodes found in the ...199619277191
screening of carnation cultivars for resistance to meloidogyne incognita.a total of 33 carnation cultivars cultured in korea were screened for resistance to the southern root-knot nematode, meloidogyne incognita. carnations were tested by either inoculating with 5,000 eggs or by transplanting into a mixture of bedding medium and soil infested with an average of 435 second-stage juveniles/300 cm(3) soil. cultivars, desio, castelaro, kappa, rara, izu pink, target, and antalia were highly resistant to m. incognita. twelve cultivars were moderately resistant, and the rem ...199619277188
mentha x piperita, mentha spicata and effects of their essential oils on meloidogyne in soil.six peppermint (mentha x piperita) and six spearmint (m. spicata) pi accessions were inoculated with meloidogyne incognita race 3 and m. arenaria race 2, under greenhouse conditions. no galls formed on roots of any of the plants inoculated with 1,800 eggs/pot. fewer than two galls per root system formed on three pi accessions of peppermint inoculated with m. incognita at 5,400 eggs/pot. only one peppermint accession developed galls when inoculated with m. arenaria, whereas none of the spearmint ...199619277186
early root response to meloidogyne incognita in resistant and susceptible alfalfa cultivars.the early events of meloidogyne incognita behavior and associated host responses following root penetration were studied in resistant (cv. moapa 69) and susceptible (cv. lahontan) alfalfa. ten-day-old seedlings of alfalfa cultivars were inoculated with second-stage juveniles (j2) and harvested 12, 24, 48, and 72 hours and 7, 14, and 21 days later. both cultivars supported similar root penetration and initial j2 migration. by 72 hours after inoculation the majority of j2 were amassed inside the v ...199619277165
differentiation of meloidogyne incognita and m. arenaria novel resistance phenotypes in lycopersicon peruvianum and derived bridge-lines.lycopersicon peruvianum pi 270435 clone 2r2 and pi 126443 clone 1mh were crossed reciprocally with three l. esculentum-l. peruvianum bridge-lines. the incongruity barrier between the two plant species was overcome; f1 progeny were obtained from crosses between four parental combinations without embryo-rescue culture. hybridity was confirmed by leaf and flower morphology and by the production of nematode-resistant f1 progeny on homozygous susceptible parents. clones of the five f1 bridgeline hybr ...199624162431
relationships between meloidogyne incognita resistance genes in lycopersicon peruvianum differentiated by heat sensitivity and nematode virulence.resistance to meloidogyne incognita (kofoid and white) chitwood in clones of lycopersicon peruvianum (l.) mill. pi 126443-1mh, 270435-2r2 and 2704353mh, their f1, a field-produced f2, and their test-cross (tc1) populations, was evaluated based on egg masses and eggs produced on root systems. reactions to m. incognita isolates differing in virulence to gene mi were determined at 25°c (mi expressed) and 32°c (mi not expressed). pi 126443-1mh, 270435-2r2, 270435-3mh, and their f1 progenies were res ...199624162430
effect of simulated rainfall on efficacy and leaching of two formulations of fenamiphos.recoverable fenamiphos in the soil and residue in squash following different simulated rainfall treatments after nematicide application were determined in a 2-year study. efficacy of fenamiphos also was evaluated. fenamiphos treatments (3 sc and 15 g) were broadcast (6.7 kg a.i./ha) over plots and incorporated into the top 15 cm of soil immediately before planting 'dixie hybrid' squash. simulated rainfall treatments of 0, 2.5, and 5.0 cm water were applied 1 day after fenamiphos application. soi ...199619277156
comparison of two sympatric pasteuria populations isolated from a tropical vertisol soil.an isolate of pasteuria (designated ppmj) recovered from the root-knot nematode meloidogyne javanica, was characterized using host preference, spore morphometrics, and serology, and compared with another sympatric pasteuria isolate (designated pphc) collected from the cyst nematode, heterodera cajani. ppmj spores were larger (x 1.5) than the pphc spores and had a mean diameter of 3.4 μm after fixation for electron microscopy. the central body of ppmj spores was about twice as big as the central ...199624415311
repulsion of meloidogyne incognita by alginate pellets containing hyphae of monacrosporium cionopagum, m. ellipsosporum, or hirsutella rhossiliensis.the responses of second-stage juveniles (j2) of meloidogyne incognita race 3 to calcium alginate pellets containing hyphae of the nematophagous fungi monacrosporiura cionopagum, m. ellipsosporum, and hirsutella rhossiliensis were examined using cylinders (38-mm-diam., 40 or 72 mm long) of sand (94% <250-mum particle size). sand was wetted with a synthetic soil solution (10% moisture, 0.06 bar water potential). a layer of 10 or 20 pellets was placed 4 or 20 mm from one end of the cylinder. after ...199619277129
a molecular study of root-knot nematode-induced feeding sites.in a compatible interaction, root-knot nematodes (meloidogyne) induce a sophisticated feeding site shortly after they have penetrated the plant root. the feeding site contains metabolically highly active giant cells. to gain insight into the molecular aspects that are typical for giant cells, a cdna library from tomato roots infected with meloidogyne incognita was differentially screened to find induced genes. among the genes identified, two extensin genes (lemmi8 and lemmi11) and a lea-like gen ...19968580972
effects of irrigation, nitrogen, and a nematicide on pearl millet.pearl millet is used mainly as a temporary forage crop in the southern united states. a new pearl millet hybrid has potential as a major grain crop in the united states. the effects of nematodes, irrigation, a nematicide, and nitrogen rates on a new pearl millet grain hybrid, hgm-100, and nematode population changes were determined in a 2-year study. root-knot nematodes (meloidogyne incognita race 1) entered the roots of pearl millet and caused minimal galling, but produced large numbers of eggs ...199519277324
effects and carry-over benefits of nematicides in soil planted to a sweet corn-squash-vetch cropping system.the effects of irrigation on the efficacy of nematicides on meloidogyne incognita race 1 population densities, yield of sweet corn, and the carry-over of nematicidal effect in the squash crop were determined in a sweet corn-squash-vetch cropping system for 3 years. fenamiphos 15g and aldicarb 15g were applied at 6.7 kg a.i./ha and incorporated 15 cm deep with a tractor-mounted rototiller. ethylene dibromide (edb) was injected at 18 kg a.i./ha on each side of the sweet corn rows (total 36 kg a.i. ...199519277323
effect of simulated rainfall on leaching and efficacy of fenamiphos.there is increasing concern in the united states about the pesticide movement in soil, groundwater contamination, and pesticide residue in food. the objective of this study was to determine the efficacy, degradation, and movement of fenamiphos (nemacur 15g) in the soil and residues in squash fruit as influenced by four simulated rainfall treatments (2.5 or 5.0 cm each applied 1 or 3 days after nematicide application) under field conditions. in 1990, concentrations of fenamiphos were greater in t ...199519277322
effect of yard waste compost on plant-parasitic nematode densities in vegetable crops.the effects of yard-waste compost on densities of plant-parasitic nematodes were determined on four crops at two sites in north florida. separate experiments were conducted with sweet corn (zea mays), cowpea (vigna unguiculata), yellow squash (cucurbita pepo), and okra (hibiscus esculentus). in each test, the design was a randomized complete block replicated four times and involving three treatments: 269 mt/ha yard-waste compost applied to the soil surface as a mulch, 269 mt/ha compost incorpora ...199519277320
influence of meloidogyne incognita on the water relations of cotton grown in microplots.the effects of meloidogyne incognita on the growth and water relations of cotton were evaluated in a 2-year field study. microplots containing methyl bromide-fumigated fine sandy loam soil were infested with the nematode and planted to cotton (gossypium hirsutum l.). treatments included addition of nematodes alone, addition of nematodes plus the insecticide-nematicide aldicarb (1.7 kg/ha), and an untreated control. meloidogyne incognita population densities reached high levels in both treatments ...199519277313
effect of ammonium ions on egg hatching and second-stage juveniles of meloidogyne incognita in axenic tomato root culture.eggs, either dispersed or in masses, and second-stage juveniles (j2) of meloidogyne incognita were exposed to different concentrations of ammonium ions in a nutrient agar medium upon which excised tomato roots were growing. egg hatch and j2 penetration of the roots was slowed or inhibited at high (54 and 324 mg/liter) but not at low (1.5 and 9 mg/liter) concentrations of ammonium nitrate. the effect of ammonium on j2 appeared to be temporary and reversible. high potassium nitrate concentration ( ...199519277298
root cortical cell spherical bodies associated with an induced resistance reaction in monoxenic cultures of meloidogyne incognita.the root-knot nematode meloidogyne incognita was monoxenically cultured on excised roots of soybean cv. pickett and tomato cv. rutgers in agar media containing either 0 to 1,600 mug/ml ammonium nitrate or 0 to 100 mug/ml urea. observations with scanning and transmission electron microscopy indicated that an elevated concentration of ammonium nitrate or urea inhibited giant cell formation and suppressed nematode development in the infected soybean roots. in the tomato roots, concentrations of amm ...199519277295
sensitivity of bedding plants to southern root-knot nematode, meloidogyne incognita race 3.thirty-two cultivars of 10 commonly-grown bedding plants, representing eight families, were evaluated for their response to infection by the root-knot nematode, meloidogyne incognita race 3, under greenhouse conditions. four ageratum cultivars, two marigold, and two salvia cultivars were rated resistant after exposure for 8 weeks. four begonia, four celosia, one dianthus, one verbena, one vinca, and three pansy cultivars were susceptible. three salvia, one begonia, one gerber, one verbena, and t ...199419279964
survey of meloidogyne spp. in tomato production fields of baix llobregat county, spain.a survey was conducted to determine the frequency and abundance of meloidogyne spp. in tomato production sites located in baix llobregat county, barcelona, spain. forty-five sites were sampled before planting and at harvest from february to october, 1991. meloidogyne spp. occurred in 49% of the sites sampled. preplant population densities ranged from 10 to 220 (x = 110)juveniles/ 250 cm(3) soil, and final population densities ranged from 20 to 1,530 (x = 410)juveniles/250 cm(3) soil. final popul ...199419279955
efficacy of fenamiphos formulations applied through irrigation for control of meloidogyne incognita on squash.management ofmeloidogyne incognita by chemigation with fenamiphos was studied in an infested field planted to m. incognita-suscepfible yellow summer squash cv. dixie hybrid. fenamiphos (vl 73.1% a.i. manufacturing concentrate in propylene glycol) was mixed with unitol dsr-90 or used as fenamiphos 3 sc (spray concentrate). both formulations, applied with 63.5 kl irrigation water per hectare, decreased numbers of m. incognita second-stage juveniles in the soil and root-gall indices, and increased ...199419279950
efficacy and compatibility for fenamiphos and eptc applied in irrigation water for nematode and weed control in snapbean production.a nematicide (fenamiphos) and a herbicide (eptc) were injected into a sprinkler irrigation system separately and as tank mixtures and applied in 25.4 kl water/ha for nematode and weed control on snapbean. there were no differences (p = 0.05) between methods of injection of fenamiphos + eptc on efficacy or crop response. the root-gall indices of cultivars eagle and gv 50 were lower in fenamiphos-treated plots than those treated with eptc alone and untreated plots. the yield and crop value were gr ...199419279949
influence of 1,3-dichloropropene, fenamiphos, and carbofuran on meloidogyne incognita populations and yield of chile peppers.field trials were conducted during 1986, 1988, 1989, and 1991 to compare the effects of 1,3-dichloropropene, fenamiphos, and carbofuran on yield and quality of chile peppers (capsicum annuum) in soil infested with meloidogyne incognita. when compared with untreated plots, numbers of m. incognita juveniles recovered from soil 60 and(or) 90 days after chile pepper emergence were reduced (p = 0.05) following 1,3-d treatment every year except 1986. nematode numbers were also reduced (p = 0.05) by fe ...199419279948
effect of tillage and crop residue management on nematode densities on corn.effects of winter cover crop management on nematode densities associated with a subsequent corn (zea mays) crop were examined in five sites in north florida. two sites had received winter cover crops of lupine (lupinus angustifolius), and one site each had rye (secale cereale), hairy vetch (vicia villosa), and crimson clover (trifolium incarnatum). in each site, five different management regimes were compared: 1) conventional tillage after the cover crop was removed for forage; 2) conventional t ...199419279946
reaction of ten cultivars of watermelon (citrullus lanatus) to a puerto rican population of meloidogyne incognita.ten cultivars of watermelon were evaluated for their response to a puerto rican population of meloidogyne incognita under greenhouse conditions in a 2-year study (1989 and 1990). ten-day-old seedlings were planted in steam-sterilized soil in 15-cm-d plastic pots. the nematode inoculum consisted of 10,000 eggs and (or) second-stage juveniles (j2)/plant. the cultivars were sugar baby, charleston gray, seedless, prince charles, charleston 76, jubilee, florida giant, royal charleston, royal sweet, a ...199419279940
optimal levels of meloidogyne incognita inoculum for infection of tomato and peach in vitro.penetration of second-stage juveniles (j2) of meloidogyne incognita into tomato root explants and in vitro propagated peach plantlet roots were compared. five inoculum levels were used: 25, 50, 75, 100, and 200 j2 for tomato; and 50, 100, 200, 500, and 1,000j2 for peach. the greatest root penetration into tomato was 30% at the 75 j2 level, but the maximum penetration into peach roots was only 8% at the 200 j2 level. the difference (p = 0.05) in penetration of m. incognita at all inoculum levels ...199419279926
partial characterization of cytosolic superoxide dismutase activity in the interaction of meloidogyne incognita with two cultivars of glycine max.the closely related soybean (glycine max) cultivars centennial and pickett 71 were confirmed to be resistant and susceptible, respectively, to the root-knot nematode meloidogryne incognita. increases in superoxide dismutase (sod) activity were detected in roots of both soybean cultivars 48 hours following inoculation. superoxide dismutase activity increased in roots of the susceptible cultivar overall, but declined after 96 hours in roots of the resistant cultivar. the isoelectric points of sod ...199419279911
low-temperature scanning electron microscope observations of the meloidogyne incognita egg mass: the gelatinous matrix and embryo development.the root-knot nematode meloidogyne incognita was cultured monoxenically on excised tomato roots. galls and egg masses were observed daily using a light microscope. two phases were distinguished in the gelatinous matrix of the egg mass: a translucent, amorphous material on the surface of the egg mass and a denser, layered phase in which nematode eggs were deposited. egg masses were also cryofixed, fractured, and observed as frozen, hydrated specimens on a cold stage in a scanning electron microsc ...199419279909
trans-splicing of a meloidogyne incognita mrna encoding a putative esophageal gland protein.a monoclonal antibody, 7a9, specific for antigens in the subventral esophageal glands of adult female meloidogyne incognita and for antigens in the longitudinal muscles of second-stage juveniles, was used to isolate a clone from a m. incognita cdna expression library. the corresponding genomic dna was isolated by hybridization and the gene designated sec-1. dna sequence analysis of sec-1 revealed the presence of 9 introns having structural similarities to introns from the free-living nematode ca ...19947891751
reproduction of virulent isolates of meloidogyne incognita on susceptible and mi-resistant tomato.the reproductive potential of natural and laboratory-selected meloidogyne incognita isolates virulent against the tomato mi resistance gene, all derived from a single egg-mass, were compared when the nematodes were inoculated on susceptible and resistant tomato. fewer second-stage juveniles (p = 0.01) of the two virulent populations selected under laboratory conditions matured to females on the resistant tomato compared to the susceptible cultivar. in contrast, no differences were found between ...199419279899
dna sequence and expression analysis of root-knot nematode-elicited giant cell transcripts.fifty-eight cdna clones isolated from a library of transcripts exhibiting up regulation in tomato root giant cells induced by infection with the parasitic nematode meloidogyne incognita were characterized. a survey of plant tissues identified 31 transcripts present in tissues other than root, including actively dividing and expanding tissues and mature leaf tissues. the identities of approximately 20% of the giant cell transcripts were inferred from dna sequence data; they include sequences enco ...20118012051
penetration and development of meloidogyne incognita in roots of resistant and susceptible corn genotypes.rates of penetration and development ofmeloidogyne incognita race 4 in roots of resistant (inbred mp307, and s4 lines derived from the open-pollinated varieties tebeau and old raccoon) and susceptible (pioneer 3110) corn genotypes were determined. seedlings grown in styrofoam containers were inoculated with 5,000 eggs of m. incognita. roots were harvested at 3-day intervals starting at 3 days after inoculation (dai) to 27 dai and stained with acid fuchsin. penetration of roots by second-stage ju ...199419279873
effect of crop rotation and tillage on nematode densities in tropical corn.effects of tillage and crop rotation on nematode densities in tropical corn (zea mays cv. pioneer x304c) were examined in a factorial experiment with two rotation crops and two tillage practices (no-till vs. conventional-till), conducted in each of three seasons (1990-1992) in north florida. the rotation treatments consisted of sorghum (sorghum bicolor cv. dekalb br64) or soybean (glycine max) grown during the 1989 season. densities of meloidogyne incognita (race 1) remained lower throughout the ...199319279846
colonization of greenhouse nematode cultures by nematophagous mites and fungi.unproductive > 7-year-old greenhouse cultures of citrus nematode (tylenchulus semipenetrans) had a well-developed soil invertebrate fauna that included nematophagous mite species characteristic of florida citrus groves. nematophagous mite densities in box cultures were 285 +/- 42 mites/liter, 2.5 to 25 times higher than densities in citrus nematode-infested groves. vigorous root-knot nematode (meloidogyne incognita) cultures grown in steam-pasteurized soil had few nematophagous mites until more ...199319279841
effects of 1,3-dicliloropropene for meloidogyne incognita management on cotton produced under furrow irrigation.field trials were conducted during 1990 to evaluate the effects of preplant soil fumigation with 1,3-dichloropropene (1,3-d) on yield and fiber quality of furrow-irrigated cotton cultivars subjected to high population densities of meloidogyne incognita. we measured the responses of eight upland cotton cultivars with different levels of root-knot nematode resistance and compared the responses of upland and pima cottons. reductions in lint weight ranged from 10 to 52% among cultivars grown in soil ...199319279835
spatial and temporal interactions of meloidogyne incognita and soybean.the spatial and temporal dynamics of meloidogyne incognita, relative to soybean shoot and root growth in field microplots, were determined at 11 sampling dates during a growing season. the population dynamics of m. incognita on soybean were dependent on initial population (pi), soil moisture, and root spatial distribution. final egg and juvenile population densities were greatest in plots with higher pi. the population densities of juveniles and eggs were highest from mid- to late-season and wer ...199319279833
dynamics of concomitant populations of meloidogyne incognita and criconemella xenoplax on peach.the interaction between meloidogyne incognita and criconemella xenoplax on nematode reproduction and growth of lovell peach was studied in field microlots and the greenhouse. meloidogyne incognita suppressed reproduction of c. xenoplax in both field and greenhouse experiments. tree growth, as measured by trunk diameter, was reduced (p </= 0.05) in the presence of m. incognita as compared with c. xenoplax of the uninoculated control trees 26 months following inoculation. a similar response regard ...199319279823
response of peach scion cultivars and rootstocks to meloidogyne incognitain vitro and in microplots.the response of the peach scion cultivars, jerseyqueen, redhaven, compact redhaven, and rio oso gem and rootstocks 'lovely and 'nemaguard' to inoculation with meloidogyne incognita was compared in vitro and in microplots. one or more parameters monitored in vitro correlated with at least one parameter monitored in microplots, 4 years after tree planting (1989). a range of responses was observed from highlysusceptible in lovell to resistant in nemaguard. in vitro and microplot data suggest high a ...199319279797
population dynamics of plant-parasitic nematodes on cover crops of corn and sorghum.buildup of plant-parasitic nematode populations on corn (zea mays), soybean (glycine max), and sorghum (sorghum bicolor) were compared in 1991 and 1992. final population densities (pf) of meloidogyne incognita were lower following sorghum than after soybean in both seasons, and pf after sorghum was lower than pf after corn in 1992. in both seasons, pf differed among the sorghum cultivars used. no differences in pf on corn, sorghum, and soybean were observed for criconemella spp. (a mixture of c. ...199319279793
dynamics of the nuclear complement of giant cells induced by meloidogyne incognita.the total numbers of nuclei in giant cells induced by meloidogyne incognita in pea, lettuce, tomato, and broad bean were determined. mature giant cells from pea had the most nuclei per giant cell with a mean of 59 +/- 23, lettuce had the fewest with 26 +/- 16, and tomato and broad bean were intermediate. the rate of increase in numbers of nuclei for all plant species was greatest during the first 7 days after inoculation. no mitotic activity was observed in giant cells associated with adult nema ...199319279788
energetics of meloidogyne incognita on resistant and susceptible alyceclover genotypes.to determine the energy cost of a population of meloidogyne incognita on the roots of alyceclover, nematode biomass was estimated and equations in the literature were used to calculate energy budgets. amounts of energy consumed, respired, or used in production of nematode biomass were calculated. results suggested that severe infestations of root-knot nematodes can remove significant quantities of energy from their hosts. over a 36-day period, a population of 2.6 females of m. incognita per root ...199319279766
characterization of anionic peroxidases in tomato isolines infected by meloidogyne incognita.changes in peroxidase activity during nematode infection were studied using root extracts of tomato near-isogenic lines differing in resistance to meloidogyne incognita. total peroxidase activity increased slightly in crude extracts of four susceptible isolines but doubled in two resistant lines, monita and motaci. nematode infection enhanced levels of both p-phenylenediamine-pyrocatechol oxidase and syringaldazine oxidase 7 days after inoculation, especially in resistant lines. this elevated pe ...199319279765
recovery and longevity of egg masses of meloidogyne incognita during simulated winter survival.effects of soil matrix potential on longevity of egg masses of meloidogyne incognita were determined during simulated winter conditions. egg masses were recovered from isolated root fragments incubated in field soil at matrix potentials of -0.1, -0.3, -1.0, and -4.0 bars throughout winter survival periods of 10 weeks for tomato roots and 12 weeks for cotton roots. egg masses were more superficial on cotton roots than on tomato roots and were more easily dislodged from cotton roots during recover ...199319279764
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