Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| polyploidy and reproductive patterns in the root-knot nematode meloidogyne hapla. | 1966 | 5927453 | |
| pachytene karyotype analysis of tetraploid meloidogyne hapla females by electron microscopy. | pairing of homologous chromosomes results in the formation of 34 synaptonemal complexes (sc) at pachytene, corresponding to the 34 bivalents at metaphase i. no multivalent associations were observed and pairing occurs two-by-two. the modified sc, which lacks a central element, does not affect the pairing process. only one end of the sc is attached to the nuclear envelope, although either end can attach. total sc length and the number of recombination nodules in the tetraploid were about 1.5 time ... | 1981 | 7327051 |
| the ultrastructure of sperm development in the plant-parasitic nematode meloidogyne hapla. | 1980 | 7381988 | |
| a basic serine protease from paecilomyces lilacinus with biological activity against meloidogyne hapla eggs. | scanning electron micrographs of the nematode-egg-parasitic fungus paecilomyces lilacinus infecting eggs of the root-knot nematode meloidogyne spp. suggested the involvement of lytic enzymes. when grown on a liquid mineral salts medium, supplemented with different substrates as the sole n- and c-source, the fungus produced an extracellular protease. colloidal chitin, vitellin and intact eggs of the root-knot nematode meloidogyne hapla induced proteolytic activity that was repressed by glucose. t ... | 1995 | 7773385 |
| cloning and characterization of two satellite dnas in the low-c-value genome of the nematode meloidogyne spp. | two highly reiterated styi satellite dnas have been cloned from two nematode species: one from meloidogyne hapla and another from m. incognita. the monomeric units of these two satellites have a repeat length of 169 and 295 bp, respectively. these styi repeated element families constitute 5% of the m. hapla and 2.5% of the m. incognita haploid genomes. the a + t content is elevated in both families (i.e., 68% and 77%, respectively). nucleotide methylation and transcriptional activity are negativ ... | 1994 | 8125299 |
| satellite dna as a target for pcr-specific detection of the plant-parasitic nematode meloidogyne hapla. | the polymerase chain reaction was evaluated for its ability to amplify dna sequences specific for the root-knot nematode meloidogyne hapla, using oligonucleotides whose sequence was deduced from the satellite dna previously cloned in this species as primers. as expected, ladder patterns of monomers and multimers of an approximate 150-170-bp repeat were amplified from purified genomic dna of all the m. hapla isolates studied, while no amplification was detected with the five other meloidogyne spe ... | 1995 | 8593688 |
| identification of stable plant cystatin/nematode proteinase complexes using mildly denaturing gelatin/polyacrylamide gel electrophoresis. | the biochemical interactions between two cystatins from rice seeds, oryzacystatin i (oci) and oryzacystatin ii (ocii), and the cysteine proteinases from three plant parasitic nematodes, meloidogyne hapla, m. incognita and m. javanica, were assessed using standard protease assays and mildly denaturing gelatin/polyacrylamide gel electrophoresis (gelatin/page). activity detected in extracts of preparasitic second-stage larvae (j2) from m. hapla was optimal at ph 5.5 and was inhibited in vitro by th ... | 1996 | 8874065 |
| evolution of the at-rich mitochondrial dna of the root knot nematode, meloidogyne hapla. | mitochondrial dna of the root knot nematode meloidogyne hapla was investigated for intraspecific diversity and divergence from other parthenogenetic root knot nematodes. a 1,900-bp fragment containing coii, trnahis, 16s rrna, nd3 and cyt b genes has been cloned and sequenced from one individual and an 1,188-bp region within this region was sequenced from four other australian isolates. m. hapla mtdna is more than 80% at-rich, like other meloidogyne spp. nucleotide diversity within m. hapla is so ... | 1997 | 9000752 |
| a new alui satellite dna in the root-knot nematode meloidogyne fallax: relationships with satellites from the sympatric species m. hapla and m. chitwoodi. | a highly abundant satellite dna comprising 20% of the meloidogyne fallax (nematoda, tylenchida) genome was cloned and sequenced. the satellite monomer is 173 bp long and has a high a + t content of 72.3%, with frequent runs of a's and t's. the sequence variability of the monomers is 2.7%, mainly due to random distribution of single-point mutations. a search for evidence of internal repeated subunits in the monomer sequence revealed a 6-bp motif (aaattt) for which five degenerated repeats, differ ... | 1998 | 9729876 |
| 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 ... | 2000 | 10675748 |
| genetic diversity of root-knot nematodes from brazil and development of scar markers specific for the coffee-damaging species. | rapd markers were used to characterize the genetic diversity and relationships of root-knot nematodes (rkn) (meloidogyne spp.) in brazil. a high level of infraspecific polymorphism was detected in meloidogyne arenaria, meloidogyne exigua, and meloidogyne hapla compared with the other species tested. phylogenetic analyses showed that m. hapla and m. exigua are more closely related to one another than they are to the other species, and illustrated the early divergence of these meiotically reproduc ... | 2002 | 12416618 |
| nematode-trapping fungi: evaluation of axenic healthy and galled roots as trap inducers. | larvae of meloidogyne hapla chit. induced abundant trap formation in the predaceous fungus arthrobotrys conoides drechs. under similar aseptic conditions, neither healthy roots of lycopersicon esculentum mill, nor roots parasitized by the root-knot nematode induced traps. | 1964 | 14190248 |
| internalization of escherichia coli o157:h7 following biological and mechanical disruption of growing spinach plants. | the internalization and persistence of a bioluminescent escherichia coli o157:h7 ph1 was investigated in growing spinach plants that had been either biologically or mechanically damaged. in control (undamaged) plants cultivated in soil microcosms inoculated with e. coli o157:h7 phl, the bacterium was recovered from surface-sterilized root tissue but not from leaves. mechanical disruption of the seminal root and root hairs of the plants did not result in the internalization of the pathogen into t ... | 2005 | 16355819 |
| [diversity of actinomycetes associated with root-knot nematode and their potential for nematode control]. | twenty actinomycetes were isolated from root-knot nematode eggs and females collected from 11 plant root samples infested by meloidogyne spp.. the isolates were assigned to the genera streptomyces, nocardia and pseudonocardia respectively, based on analysis of morphological characteristics, cell-wall daps and 16s rrna gene sequences. 80% of them were streptomycetes. biocontrol potential of the isolates against meloidogyne hapla was evaluated in liquid culture in vitro. the average percentages of ... | 2006 | 17037062 |
| morphological and molecular characteristics of a new species of pasteuria parasitic on meloidogyne ardenensis. | a species of the hyper-parasitic bacterium pasteuria was isolated from the root-knot nematode meloidogyne ardenensis infecting the roots of ash (fraxinus excelsior). it is morphologically different from some other pasteuria pathogens of nematodes in that the spores lack a basal ring on the ventral side of the spore and have a unique clumping nature. transmission electron microscopy (tem) showed that the clumps of spores are not random aggregates but result from the disintegration of the suicide ... | 2007 | 17399736 |
| comprehensive transcriptome profiling in tomato reveals a role for glycosyltransferase in mi-mediated nematode resistance. | root-knot nematode (rkn; meloidogyne spp.) is a major crop pathogen worldwide. effective resistance exists for a few plant species, including that conditioned by mi in tomato (solanum lycopersicum). we interrogated the root transcriptome of the resistant (mi+) and susceptible (mi-) cultivars 'motelle' and 'moneymaker,' respectively, during a time-course infection by the mi-susceptible rkn species meloidogyne incognita and the mi-resistant species meloidogyne hapla. in the absence of rkn infectio ... | 2007 | 17434994 |
| meiotic parthenogenesis in a root-knot nematode results in rapid genomic homozygosity. | many isolates of the plant-parasitic nematode meloidogyne hapla reproduce by facultative meiotic parthenogenesis. sexual crosses can occur, but, in the absence of males, the diploid state appears to be restored by reuniting sister chromosomes of a single meiosis. we have crossed inbred strains of m. hapla that differ in dna markers and produced hybrids and f(2) lines. here we show that heterozygous m. hapla females, upon parthenogenetic reproduction, produce progeny that segregate 1:1 for the pr ... | 2007 | 17483427 |
| effect on meloidogyne hapla of excised tomato roots treated with alpha-methoxyphenylacetic acid. | 1956 | 17736439 | |
| plant parasitic nematodes: a new mechanism for injury of hosts. | pathological effects of ditylenchus dipsaci and meloidogyne hapla are related to the disturbance of the auxin balance in the host by the nematode. the parasites produce an auxin inactivator, apparently enzymatic, that enables ditylenchus dipsaci to stunt host stem apices and meloidogyne hapla to reduce its galling potential. | 1965 | 17790829 |
| laboratory trials to infect insects and nematodes by some acaropathogenic hirsutella strains (mycota: clavicipitaceous anamorphs). | laboratory assays have been carried out to artificially infect insect larvae of the birch bark-beetle (scolytus ratzeburgi jans.-coleoptera, scolytidae) and codling moth cydia pomonella l. -lepidoptera, tortricidae) as well as the potato cyst nematode-globodera rostochiensis wollenweber, sugar beet nematode-heterodera schachtii schmidt and root-knot nematode-meloidogyne hapla chif (nematoda, heteroderidae), by the phialoconidia of some fungal species of the genus hirsutella. from among four spec ... | 2008 | 17920621 |
| 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 ... | 2008 | 18171577 |
| a novel negative regulatory factor for nematicidal cry protein gene expression in bacillus thuringiensis. | a 3-kb hindiii fragment bearing the cry6aa2 gene and the adjacent and intergenic regions was cloned from bacillus thuringiensis strain ybt-1518. two open reading frames (orfs), namely, orf1 (termed cry6aa2) and orf2 that were separated by an inverted-repeat sequence were identified. orf1 encoded a 54-kda protein that exhibited high toxicity to the plant-parasitic nematode meloidogyne hapla. the orf2 expression product was not detected by sds-page, but its mrna was detected by rt-pcr. the orf2 co ... | 2008 | 18600043 |
| sequence and genetic map of meloidogyne hapla: a compact nematode genome for plant parasitism. | we have established meloidogyne hapla as a tractable model plant-parasitic nematode amenable to forward and reverse genetics, and we present a complete genome sequence. at 54 mbp, m. hapla represents not only the smallest nematode genome yet completed, but also the smallest metazoan, and defines a platform to elucidate mechanisms of parasitism by what is the largest uncontrolled group of plant pathogens worldwide. the m. hapla genome encodes significantly fewer genes than does the free-living ne ... | 2008 | 18809916 |
| new strategy for isolating novel nematicidal crystal protein genes from bacillus thuringiensis strain ybt-1518. | we have developed a strategy for isolating cry genes from bacillus thuringiensis. the key steps are the construction of a dna library in an acrystalliferous b. thuringiensis host strain and screening for the formation of crystal through optical microscopy observation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) analyses. by this method, three cry genes--cry55aa1, cry6aa2, and cry5ba2--were cloned from rice-shaped crystals, producing b. thuringiensis ybt-1518, which co ... | 2008 | 18820056 |
| variation in virulence within meloidogyne chitwoodi, m. fallax, and m. hapla on solanum spp. | abstract the virulence of meloidogyne hapla, m. chitwoodi, and m. fallax was studied on genotypes of solanum spp. in a greenhouse. juveniles of 11 m. hapla race a isolates, 3 m. hapla race b isolates, and 5 mono-female lines of a m. hapla race a isolate were inoculated on s. chacoense, s. hougasii, and s. sparsipilum. juveniles of eight m. chitwoodi isolates, five m. fallax isolates, and six mono-female lines of a m. chitwoodi isolate were inoculated on s. bulbocastanum, s. chacoense, s. hougasi ... | 1998 | 18944937 |
| host-specific pathogenicity and genome differences between inbred strains of meloidogyne hapla. | five isolates of m. hapla originating from the netherlands and california were inbred by sequential transfer of single egg masses to produce six strains. cytological examination showed that oocytes of these strains underwent meiosis and had n = 16 chromosomes. strains were tested for ability to infect and to develop on several hosts by in vitro assays. the two strains from california infected tomato roots at a higher rate than those from the netherlands, but no difference among strains was seen ... | 2006 | 19259441 |
| damage and management of meloidogyne hapla using oxamyl on carrot in new york. | the northern root-knot nematode (meloidogyne hapla) is a major pathogen of processing carrot in new york, significantly reducing marketable yield and profitability. severely infected carrots are stubby, galled and forked and therefore unmarketable. in field microplot trials in 1996 and 1998, the incidence and severity of root-galling increased and the marketable yield of carrot decreased as the initial inoculum density of m. hapla was increased from 0 to 8 eggs/cm(3) soil, in mineral or organic ... | 2006 | 19259467 |
| effect of crop rotation on meloidogyne spp. and pratylenchus spp. populations in strawberry fields in taiwan. | changes in population levels of meloidogyne hapla, m. incognita, pratylenchus coffeae, and p. penetrans were studied in 12 strawberry fields in the dahu region of taiwan. ten potential rotation crops and two cultural practices were evaluated for their effect on nematode populations and influence on strawberry yield. rotation with rice or taro and the cultural practice of flooding and bare fallowing for four months were found to reduce nematode soil populations to two or fewer nematodes per 100 m ... | 2006 | 19259538 |
| effect of compost and manure soil amendments on nematodes and on yields of potato and barley: a 7-year study. | a 7-year study located in prince edward island, canada, examined the influence of compost and manure on crop yield and nematode populations. the compost used in this study consisted of cull waste potatoes, sawdust, and beef manure in a 3:3:1 ratio, respectively. no plant-parasitic nematodes were detected in samples collected from windrow compost piles at 5- and 30-cm depths prior to application on field plots. low population densities of bacterial-feeding nematodes were recovered from compost wi ... | 2003 | 19262763 |
| nucleotide substitution patterning within the meloidogyne rdna d3 region and its evolutionary implications. | evolutionary relationships based on nucleotide variation within the d3 26s rdna region were examined among acollection of seven meloidogyne hapla isolates and seven isolates of m. arenaria, m. incognita, and m. javanica. using d3a and d3b primers, a 350-bp region was pcr amplified from genomic dna and double-stranded nucleotide sequence obtained. phylogenetic analyses using three independent clustering methods all provided support for a division between the automictic m. hapla and the apomictic ... | 2003 | 19262771 |
| morphological and molecular evaluation of a meloidogyne hapla population damaging coffee (coffea arabica) in maui, hawaii. | an unusual population of meloidogyne hapla, earlier thought to be an undescribed species, was found causing large galls, without adventitious roots, and substantial damage to coffee in maui, hawaii. only in brazil had similar damage to coffee been reported by this species. unlike m. exigua from south and central america, this population reproduced well on coffee cv. mokka and m. incognita-susceptible tomato but poorly on tomato with the mi resistance gene. characterization included sem images, e ... | 2005 | 19262853 |
| relationship between levels of cyanide in sudangrass hybrids incorporated into soil and suppression of meloidogyne hapla. | sudangrass cv. trudan 8 has been demonstrated to suppress infection of vegetables by meloidogyne hapla (mh). hydrogen cyanide, released from the degradation of the cyanogenic glucoside (dhurrin) during decomposition of trudan 8, was the primary factor involved in suppression of mh on vegetables. the cyanide ion level in leaf tissue of 14 hybrids of sudangrass varied between 0.04 (cv. sx-8) to 1.84 parts per million (cv. 840f). the suppressive activity of the sudangrass hybrids against mh was ass ... | 2002 | 19265902 |
| seasonal populations of pratylenchus penetrans and meloidogyne hapla in strawberry roots. | strawberry roots were sampled through the year to determine the populations and distribution of pratylenchus penetrans and meloidogyne hapla. three strawberry root types were sampled-structural roots; feeder roots without secondary tissues; and suberized, black perennial roots. both lesion and root-knot nematodes primarily infected feeder roots from structural roots or healthy perennial roots. few nematodes were recovered from soil, diseased roots, or suberized roots. lesion nematode recovery wa ... | 2002 | 19265965 |
| phenotypic and molecular analysis of a pasteuria strain parasitic to the sting nematode. | pasteuria strain s-1 was found to parasitize the sting nematode belonolaimus longicaudatus. s-1 spores attached to several strains of b. longicaudatus from different geographical locations within the united states. however, they did not adhere to any of the following species: heterodera schachtii, longidorus africanus, meloidogyne hapla, m. incognita, m. javanica, pratylenchus brachyurus, p. scribneri, p. neglectus, p. penetrans, p. thornei, p. vulnus, and xiphinema spp. the 16s rrna genes from ... | 2001 | 19266005 |
| 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 ... | 1999 | 19270876 |
| 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 ... | 1999 | 19270925 |
| plant-parasitic nematodes associated with grapevines, vitis vinifera, in oregon vineyards. | a survey of vineyards in western oregon was conducted in 1994 and 1995 to determine the association of plant-parasitic nematodes with vine health. seventy vineyards in four regions of western oregon (16 to 21 vineyards per region) were sampled. the regions were the northern, middle, and southern willamette valley, and southern oregon. vineyards were selected and partitioned into blocks by variety, age of planting, crop history, and soil characteristics. mesocriconema xenoplax, xiphinema american ... | 1999 | 19270927 |
| influence of rotation crops on the strawberry pathogens pratylenchus penetrans, meloidogyne hapla, and rhizoctonia fragariae. | field microplot, small plot, and greenhouse experiments were conducted to determine the effects of rotation crops on pratylenchus penetrans, meloidogyne hapla, and rhizoctonia fragariae populations. extraction of p. penetrans from roots and soil in microplots and field plots planted to rotation crops was highest for garry oat, lowest for triple s sorgho-sudangrass and saia oat, and intermediate for strawberry, buckwheat, and canola. isolation of r. fragariae from bait roots was highest for straw ... | 1999 | 19270931 |
| suppression of meloidogyne hapla and its damage to lettuce grown in a mineral soil amended with chitin and biocontrol organisms. | chitin was used as soil amendment in fiberglass field microplots, alone or with one or a combination of two to three species of hirsutella rhossiliensis, paecilomyces marquandii, verticillium chlamydosporium, bacillus thuringiensis, and streptomyces costaricanus. sudangrass and rapeseed were planted as cover crops and incorporated into soil as green manure amendments. chitin amendment alone increased the marketable yield of lettuce in 1995 and reduced root-galling ratings and the reproduction of ... | 1999 | 19270942 |
| efficacy of bacillus thuringiensis, paecilomyces marquandii,and streptomyces costaricanus with and without organic amendments against meloidogyne hapla infecting lettuce. | chitin, wheat mash, or brewery compost were incorporated into unfumigated and methyl bromide-fumigated organic soils placed in microplots formed from cylindrical drainage tiles (0.25 m-diam. clay tile). after 3 weeks, meloidogyne hapla and cell or spore suspensions of bacillus thuringiensis, paecilomyces marquandii, and streptomyces costaricanus were individually added to the soils of designated microplots. a b. thuringiensis + s. costaricanus combination was also tested. lettuce seedlings, cv. ... | 2000 | 19270951 |
| hirsutella rhossiliensisand verticillium chlamydosporium as biocontrol agents of the root-knot nematode meloidogyne hapla on lettuce. | hirsutella rhossiliensis and verticillium chlamydosporium infected second-stage juveniles (j2) and eggs of meloidogyne hapla, respectively, in petri dishes and in organic soil in pots planted to lettuce in the greenhouse. in vitro, h. rhossiliensis produced 78 to 124 spores/infected j2 of m. hapla. the number of j2 in roots of lettuce seedlings decreased exponentially with increasing numbers of vegetative colonies of h. rhossiliensis in the soil. at an infestation of 8 m. hapla eggs/cm(3) soil, ... | 2000 | 19270953 |
| trichoderma harzianum endochitinase does not provide resistance to meloidogyne hapla in transgenic tobacco. | eggs of meloidogyne hapla contain chitin, a substrate for chitinase. our goal was to determine if endochitinase from the biocontrol fungus t. harzianum expressed in transgenic tobacco increases resistance to this nematode. endochitinase-transgenic t tobacco seedlings expressing increased endochitinase activity in leaves (11 to 125 times over control) and roots (2 to 15 times over control) were transferred to quartz sand:loam soil mix (4:1 ratio) and inoculated with 5,000 m. hapla eggs/pot. tomat ... | 2000 | 19270979 |
| a pcr assay to identify and distinguish single juveniles of meloidogyne hapla and m. chitwoodi. | random amplified polymorphic dna (rapd) bands that distinguish meloidogyne hapla and m. chitwoodi from each other, and from other root-knot nematode species, were identified using a series of random octamer primers. the species-specific amplified dna fragments were cloned and sequenced, and then the sequences were used to design 20-mer primer pairs that specifically amplified a dna fragment from each species. using the primer pairs, successful amplifications from single juveniles were readily at ... | 1997 | 19274128 |
| host-parasite relationships of meloidogyne trifoliophila isolates from new zealand. | root-infecting nematodes are commonly found on white clover in new zealand pasture where they reduce yield, nitrogen fixation, and persistence. the dominant root-knot nematode on white clover in new zealand is confirmed in this study as meloidogyne trifoliophila by isozyme phenotype comparison with the type population from tennessee. results from a host differential test differed in the host ranges of m. trifoliophila and m. hapla from new zealand locations, with m. trifoliophila failing to repr ... | 1997 | 19274134 |
| importance of temperature in the pathology of meloidogyne hapla and m. chitwoodi on legumes. | effects of temperatures on the host-parasite relationships were studied for three legume species and four populations of root-knot nematodes from the western united states. the nematode populations were meloidogyne hapla from california (mhca), utah (mhut), and wyoming (mhwy), and a population of m. chitwoodi from utah (mcut). the legumes were milkvetch (astragalus cicer), alfalfa (medicago sativa), and yellow sweet clover (melilotus officinalis). all milkvetch plants survived inoculation with a ... | 1997 | 19274139 |
| antioxidant enzymes in phytoparasitic nematodes. | presence of different antioxidant enzymes, such as superoxide dismutase (sod), catalase, and ascorbate, p-phenilendiamine-pyrocathecol (ppd-pc), o-dianisidine, and guaiacol isoperoxidases, was shown in the phytoparasific nematode species meloidogyne incognita, m. hapla, globodera rostochiensis, g. pallida, heterodera schachtii, h. carotae, and xiphinema index. the activity of the enzymes tested differed among the life stages examined. sod was present in cysts but was not detected in meloidogyne ... | 1997 | 19274144 |
| effects of meloidogyne spp. and rhizoctonia solani on the growth of grapevine rootings. | a disease complex involving meloidogyne incognita and rhizoctonia solani was associated with stunting of grapevines in a field nursery. nematode reproduction was occurring on both susceptible and resistant cultivars, and pot experiments were conducted to determine the virulence of this m. incognita population, and of m. javanica and m. hapla populations, to v. vinifera cv. colombard (susceptible) and to v. champinii cv. ramsey (regarded locally as highly resistant). the virulence of r. solani is ... | 1997 | 19274149 |
| effect of the mi gene in tomato on reproductive factors of meloidogyne chitwoodi and m. hapla. | the effect of the mi gene on the reproductive factor of meloidogyne chitwoodi and m. hapla, major nematode pests of potato, was measured on nearly isogenic tomato lines differing in presence or absence of the mi gene. the mi allele controlled resistance to reproduction of race 1 of m. chitwoodi and to one of two isolates of race 2. no resistance to race 3 of m. chitwoodi or to m. hapla was found. variability in response to isolates of race 2 may reflect diversity of virulence genotypes heretofor ... | 1997 | 19274176 |
| fungi parasitic on juveniles and egg masses of meloidogyne hapla in organic soils from new york. | fungi associated with egg masses and juveniles of meloidogyne hapla were isolated from organic soil samples obtained from five fields planted to lettuce or onion in newyork. the soil samples were placed in sterilized clay pots, infested with m. hapla, and planted to lettuce. after 4 months, egg masses and juveniles were surface-disinfested, plated on water agar, and examined for fungal infection. depending on the soil sample, fungal isolates were recovered from 13% to 30%, and from 5% to 24% of ... | 1998 | 19274258 |
| management of plant-parasitic nematodes on peanut with selected nematicides in north carolina. | field experiments were conducted to determine peanut growth and yield responses to selected fumigant and nonfumigant nemaficide treatments in 1988 and 1989. all treatments with the fumigant 1, 3-d significantly suppressed nematode reproduction (meloidogyne arenaria, m. hapla, and mesocriconema ornatum) and enhanced peanut yields over the other treatments in four tests in 1988. yield increases with the fumigant ranged from about 20% to 100% over the untreated control. test sites in 1989 had lower ... | 1998 | 19274260 |
| evaluation of 15 trifolium spp. and of medicago sativa as hosts of four meloidogyne spp. found in new zealand. | the predominant root-knot nematode in new zealand pastures is meloidogyne trifoliophila, identified until recently as m. hapla. clarification was needed on the host range of these two species on legumes found in new zealand pastures and on clover species closely related to trifolium repens. in a greenhouse test, 15 trifolium spp. and medicago sativa were inoculated with eggs of m. trifoliophila, m. hapla, m. incognita, or m. javanica. all legumes tested were hosts to some degree to each of the r ... | 1997 | 19274267 |
| management of meloidogyne hapla in herbaceous perennial ornamentals by sanitation and resistance. | meloidogyne hapla can be spread in bare-root herbaceous perennial propagation material and may be difficult to control once established in new fields or in the landscape. root pruning of bare-root plants was investigated as a means of reducing spread and establishment of m. hapla. plants previously inoculated with 10,000 eggs/plant were root-pruned to remove either a portion or most of the fibrous root system without removing underground stems, buds, tubers, or tuberous roots. root pruning of ac ... | 1997 | 19274274 |
| surface coat of meloidogyne incognita. | the nematode surface coat is defined as an extracuticular component on the outermost layer of the nematode body wall, visualized only by electron microscopy. surface coat proteins of meloidogyne incognita race 3 infective juveniles were characterized by electrophoresis and western blotting of extracts from radioiodine and biotin-labeled nematodes. extraction of labeled nematodes with cetyltrimethylammonium bromide yielded a principal protein band larger than 250 kda and, with water soluble bioti ... | 1996 | 19277137 |
| role of nematodes, nematicides, and crop rotation on the productivity and quality of potato, sweet potato, peanut, and grain sorghum. | the objective of this experiment was to determine the effects of fenamiphos 15g and short-cycle potato (po)-sweet potato (sp) grown continuously and in rotation with peanut (pe)-grain sorghum (gs) on yield, crop quality, and mixed nematode population densities of meloidogyne arenaria, m. hapla, m. incognita, and mesocriconema ornatum. greater root-gall indices and damage by m. hapla and m. incognita occurred on potato than other crops. most crop yields were higher and root-gall indices lower fro ... | 1996 | 19277157 |
| host suitability of twelve leguminosae species to populations of meloidogyne hapla and m. chitwoodi. | legumes of the genera astragalus (milkvetch), coronilla (crownvetch), lathyrus (pea vine), lotus (birdsfoot trefoil), medicago (alfalfa), melilotus (clover), trifolium (clover), and vicia (common vetch) were inoculated with a population of melaidogyne chitwoodi from utah or with one of three m. hapla populations from california, utah, and wyoming.thirty-nine percent to 86% of alfalfa (m. scutellata) and 10% to 55% of red clover (t. pratense) plants survived inoculation with the nematode populati ... | 1996 | 19277158 |
| damage threshold of meloidogyne hapla to lettuce in organic soil. | lettuce was seeded in pots in the greenhouse and in field microplots in 1991 and 1992. pots and microplots were filled with untreated or fumigated organic soil infested with meloidogyne hapla at seven initial population densities (pi) (0 to 32 eggs/cm(3) soil). lettuce weight, severity of root galling, and number of eggs per root system (pf) were determined after 8 weeks. at the highest pi, m. hapla caused yield losses up to 64% in the microplots and plant death in the greenhouse tests. the sein ... | 1996 | 19277172 |
| response of additional herbaceous perennial ornamentals to meloidogyne hapla. | twenty-nine herbaceous perennial ornamentals were evaluated for root galling after 2 months in soil infested with meloidogyne hapla u n d e r greenhouse conditions. plants such as asclepias, epimedium, liriope, lithospermura, myosotis, penstemon, sidalecea, and solidago did not have galls or egg masses present on the root system and were rated as resistant. astrantia, boltonia, centranthus, and miscanthus had more than 100 galls on the roots (similar to 'rutgers' tomato controls) and were rated ... | 1996 | 19277187 |
| host suitability of 32 common weeds to meloidogyne hapla in organic soils of southwestern quebec. | thirty-two weeds commonly found in the organic soils of southwestern quebec were evaluated for host suitability to a local isolate of the northern root-knot nematode meloidogyne hapla under greenhouse conditions. galls were observed on the roots of 21 species. sixteen of the 21 had a reproduction factor (pf/pi = final number of m. hapla eggs and juveniles per initial number of m. hapla juveniles per pot) higher than carrot (pf/pi = 0.37), the major host crop in this agricultural area. tomato cv. ... | 1996 | 19277189 |
| biological relationship of meloidogyne hapla populations to alfalfa cultivars. | greenhouse and growth chamber studies were established to determine if there are pathological and physiological differences among meloidogyne hapla populations from california (ca), nevada (nv), utah (ut), and wyoming (wy) on alfalfa cultivars classified as resistant or susceptible to root-knot nematodes. in the greenhouse, plant survival was not consistent with resistance classifications. while all highly resistant nevada synthetic germplasm (nev syn xx) plants survived inoculation with all nem ... | 1995 | 19277299 |
| induced resistance to meloidogyne hapla by other meloidogyne species on tomato and pyrethrum plants. | advance inoculation of the tomato cv. celebrity or the pyrethrum clone 223 with host-incompatible meloidogyne incognita or m. javanica elicited induced resistance to host-compatible m. hapla in pot and field experiments. induced resistance increased with the length of the time between inoculations and with the population density of the induction inoculum. optimum interval before challenge inoculation, or population density of inoculum for inducing resistance, was 10 days, or 5,000 infective nema ... | 1995 | 19277310 |
| response of perennial herbaceous ornamentals to meloidogyne hapla. | sixty-nine herbaceous perennial ornamentals in 56 genera were evaluated for root galling after 2 months in soil infested with meloidogyne hapla under greenhouse conditions. plants were rated susceptible or resistant based on the number of galls present on the root system. thirty-six percent had more than 100 galls on the roots (similar to 'rutgers' tomato controls) and were rated susceptible. thirty percent of the plants tested did not have galls or egg masses present on the root system and were ... | 1995 | 19277335 |
| hermaphroditism in meloidogyne hapla. | hermaphrodites were detected in diploid and polyploid isolates of population 86-va of meloidogyne hapla. young hermaphrodites are indistinguishable from normal females. initially, hermaphrodite ovaries are filled with oocytes at various stages of development. hermaphroditism is expressed later when young oocytes in the early pachytene region of the growth zone suddenly advance to diakinesis and proceed with maturation divisions, resulting in spermatid production. spermatogenesis may be initiated ... | 1993 | 19279736 |
| isolates of meloidogyne hapla with distinct mitochondrial genomes. | because two conflicting reports of the structure of the meloidogyne hapla mitochondrial genome exist, we compared the mitochondrial dna (mtdna) purified from two isolates of m. hapla: one from san bernardino county in southern california (brdo) and the other from england. the authenticity of the brdo isolate in particular was confirmed by examination of morphological characters, isoenzyme analysis, and differential host range tests. restriction analysis revealed that mtdna from the brdo and engl ... | 1993 | 19279763 |
| suppression of meloidogyne chitwoodi with sudangrass cultivars as green manure. | meloidogyne chitwoodi race 1 reproduced on piper sudangrass (sorghum bicolor (l.) moench), 332 (sudangrass hybrid), and p855f and p877f (sorghum-sudangrass hybrids), but failed to reproduce efficiently on trudan 8, trudex 9 (sudangrass hybrids), and sordan 79, ss-222, and bravo ii (sorghum-sudangrass hybrids). meloidogyne chitwoodi race 2 behaved similarly and reproduced more efficiently on piper, p855f, and p877f than on trudan 8, trudex 9, or sordan 79. the mean reproductive factor for m. chit ... | 1993 | 19279773 |
| differential sensitivity of meloidogyne spp. and heterodera glycines to selected nematicides. | differential sensitivity of meloidogyne arenaria, m. hapla, m. incognita, m. javanica, and heterodera glycines races 1 and 5 to the nonfumigant nematicides aldicarb, ethoprop, and fenamiphos was evaluated using a 48-hour root-penetration bioassay. generally, h. glycines was more tolerant of the nematicides, especially ethoprop, than were the meloidogyne species. among meloidogyne species, m. incognita was most sensitive to aldicarb and fenamiphos, but its reaction to ethoprop was similar to the ... | 1993 | 19279834 |
| reproduction of plant-parasitic nematodes on winter rapeseed (brassica napus ssp. oleiferas). | the reproduction of isolates of five plant-parasitic nematode species on the winter rapeseed cultivars bridger, gorzanski, h-47, lindora, and viking was evaluated. each cultivar was a good host for helicotylenchus pseudorobustus, meloidogyne hapla, and m. incognita, all rapeseed cultivars were poor hosts for pratylenchus scribneri, in comparison with a susceptible reference host. heterodera glycines females rarely developed on any cultivar, but low numbers of juveniles invaded roots and males oc ... | 1993 | 19279854 |
| impact of thermal history on tolerance of meloidogyne hapla second-stage juveniles to external freezing. | low temperature induced physiological changes that increased the ability of second-stage juveniles of meloidogyne hapla to survive external freezing. second-stage juveniles in polyethylene glycol solution were exposed to -4 , 0, 4, or 24 c, and then their survival was determined after ice-induced freezing of the suspensions at - 4 c for 24 hours. survival was greatest for juveniles exposed to 4 c before freezing. some juveniles were killed by exposure to - 4 c before freezing of the suspensions. ... | 1992 | 19282993 |
| predisposition of broadleaf tobacco to fusarium wilt by early infection with globodera tabacum tabacum or meloidogyne hapla. | in greenhouse experiments, broadleaf tobacco plants were inoculated with tobacco cyst (globodera tabacum tabacum) or root-knot (meloidogyne hapla) nematodes 3, 2, or 1 week before or at the same time as fusarium oxysporum. plants infected with nematodes prior to fungal inoculation had greater fusarium wilt incidence and severity than those simultaneously inoculated. g. t. tabacum increased wilt incidence and severity more than did m. hapla. mechanical root wounding within 1 week of f. oxysporum ... | 1992 | 19283018 |
| effects of cropping sequences on population densities of meloidogyne hapla and carrot yield in organic soil. | the influence of various cropping sequences on population densities of meloidogyne hapla and carrot yield was studied in organic soil under microplot-and field conditions. spinach, radish, barley, oat, and wheat were poor or nonhosts for m. hapla. population densities of m. hapla were maintained or increased on cabbage, celery, lettuce, leek, marigold, and potato. marketable percent-age and root weight of carrots were greater following spinach, oat, radish, and fallow-onion than those following ... | 1992 | 19283022 |
| resistance of lathyrus species and accessions to the northern root-knot nematode, meloidogyne hapla. | the leguminous plant genus lathyrus contains many species useful for soil conservation and reclamation. some of these species may also have vaiue in the united states for forage production. the extent of genetic variation among lathyrus populations in reaction to most disease pathogens is not known. we examined 28 usda agricultural research service plant introduction accessions representing 16 lathyrus species for their ability to tolerate attack by the northern root-knot nematode, meloidogyne h ... | 1992 | 19283053 |
| distribution of heterodera carotae and meloidogyne hapla in michigan carrot production. | during 1986 and 1988, selected farms in all of the major carrot-growing counties of michigan were surveyed to determine the extent of infestation by heterodera carotae and meloidogyne hapla. both species were found in all eight counties surveyed, but not on all farms. heterodera carotae was recovered from 67.4% of the fields surveyed. meloidogyne hapla was detected in 24.8% of the samples and from 69.8% of the fields. in most cases, h. carotae and m. hapla occurred in the same field. | 1992 | 19283061 |
| further studies on the role of polyploidy in the evolution of meloidogyne. | two tetraploid isolates of meloidogyne hapla, 86p and e289p, with haploid chromosome numbers of 34 and 28, respectively, were studied cytogenetically and biologically in relation to the diploid populations, 86-va (n = 17) and e289-taiwan (n = 14), from which they had been originally isolated. both isolates were quite stable, converting to diploidy at the low rate of about 2.5%. the tetraploid isolate 86p maintained itself in competition with its diploid counterpart in mixed cultures, although an ... | 1991 | 19283121 |
| efficacy of ethoprop on meloidogyne hapla and m. chitwoodi and enhanced biodegradation in soil. | responses of egg masses, free eggs, and second-stage juveniles (j2) ofmeloidogyne hapla and m. chitwoodi to ethoprop were evaluated. the results indicated that j2 were the most sensitive, followed by free eggs and egg masses. in general, m. chitwoodi was more susceptible to ethoprop than m. hapla. ethoprop at 7.2 mug a.i./g soil protected tomato roots from upward migrating m. chitwoodi for 5 weeks. the zone of protection was extended to 10 and 20 cm below the root zone when 3.6 and 7.2 cm water ... | 1991 | 19283141 |
| resistance to root-knot nematodes in cucumber and horned cucumber. | two experiments were conducted in the greenhouse. in one experiment, cucumber (cucumis sativus) and horned cucumber (c. metuliferus) cultigens were evaluated for resistance to four root-knot nematode species (meloidogyne arenaria, m. hapla, m. incognita, and m. javanica), and, in a second experiment, a standard (12-week) test was compared with a rapid (6-week) test. in the first experiment, horned cucumber cultigens varied in response to the meloidogyne species. 'sumter' cucumber was more suscep ... | 1991 | 19283171 |
| effects of incorporation method of ethoprop and addition of aldicarb on potato tuber infection by meloidogyne hapla. | the efficacy of controlling meloidogyne hapla on potato with water incorporation of ethoprop was compared to physical incorporation before planting. the standard practice of aldicarb application for insect control was also evaluated for m. hapla suppression with and without ethoprop. physical incorporation before planting by rototilling or discing reduced (p </= 0.05) tuber infection. postplant water incorporation of ethoprop was not as effective as physical incorporation of ethoprop or postplan ... | 1991 | 19283186 |
| host suitability and response of asparagus cultivars to meloidogyne species and races. | the host-parasite relationships of asparagus and meloidogyne spp. were examined under greenhouse and microplot conditions. meloidogyne species and races differed greatly in their ability to reproduce on asparagus seedlings. meloidogyne hapla generally failed to reproduce, and m. javanica, m. arenaria race 1, and m. incognita race 3 reproduced poorly, with a reproduction factor (rf = final population/initial population) usually < 1.0. only m. arenaria race 2 and m. incognita races 1 and 4 reprodu ... | 1992 | 19283211 |
| relative damage functions and reproductive potentials of meloidogyne arenaria and m. hapla on peanut. | the reproductive potential and damage functions for meloidogyne hapla and m. arenaria race 1 on virginia-type peanuts (arachis hypogaea cv. florigiant) were determined over 2 years in microplot experiments in north carolina. peanut yield suppression and damage to pods as a result of galling were greatest in response to m. arenaria (p = 0.01). damage functions for the two species were adequately described by the quadratic models: yield (g/plot) = 398 - 17.1 (log[pi + 1]) - 17.0(log[pi + 1])(2); ( ... | 1992 | 19283222 |
| pathogenicity of two populations of meloidogyne hapla chitwood on alfalfa and sainfoin. | the pathogenicity of two populations of the northern root-knot nematode, meloidogyne hapla chitwood, population 1 (p1) from alfalfa and population 2 (p2) from sainfoin, was studied on both alfalfa and sainfoin for 25 weeks. alfalfa and sainfoin plants inoculated with p2 had significantly (p </= 0.05) higher mortality than plants inoculated with p1. plant stands over all weeks for the uninoculated control, p1, and p2 were 90.5, 78.5, and 64.0% for alfalfa and 84.5, 51.0, and 41.0% for sainfoin, r ... | 1989 | 19287580 |
| biological control of meloidogyne hapla on alfalfa and tomato with the fungus meria coniospora. | this study was to determine whether arthrobotrys flagrans, a. oligospora, and meria coniospora would control the root-knot nematode meloidogyne hapla on alfalfa and tomato. alfalfa seeds were coated with a fungus-rye powder in 2% cellulose and were planted in infested soil. three-week-old seedlings from seed treated with m. coniospora had 60% and 58% fewer galls in two experiments than did seedlings from untreated seeds. numbers of j2 in the soil were not reduced. plant growth did not improve. w ... | 1989 | 19287596 |
| efficacy of oxamyl coated on alfalfa seed with a polymer sticker in pratylenchus and meloidogyne infested soils. | a polymer sticker was used as a coating in which oxamyl was applied to seeds of alfalfa cultivar saranac for the control of pratylenchus penetrans and meloidogyne hapla. the sticker, diluted 1:1 (sticker:water) to 1:5, delayed seedling emergence during the first 4 days after planting. by day 13, however, emergence from all sticker treatments was comparable to the control. shoot growth of seedlings at day 21 was less than that of the control only from seeds coated with a 1:1 dilution; root growth ... | 1989 | 19287603 |
| susceptibility of nevada synthetic xx germplasm to a california race of meloidogyne hapla. | 1989 | 19287611 | |
| cold hardening of meloidogyne hapla second-stage juveniles. | the effect of previous exposure to low temperatures on freezing tolerance was determined for second-stage juveniles of meloidogyne hapla. juveniles in 5% polyethylene glycol 20,000 were exposed to 0-24 c for 12-96 hours, and then freezing tolerance was assessed by freezing samples at -4 c for 24 hours, thawing, and determining survival. freezing tolerance was inversely related to prefreeze temperatures of 4-24 c. prefreeze exposure to 4 c resulted in fourfold greater freezing tolerance than did ... | 1990 | 19287695 |
| growth of carrot and tomato from oxamyl-coated seed and control of meloidogyne hapla. | oxamyl was coated on carrot (daucus carota l. cv. spartan fancy-80) and tomato (lycopersicon esculentum mill. cv. glamour) seeds with a polymer sticker for the control of meloidogyne hapla. the sticker diluted in water 1:1 delayed carrot seedling emergence. oxamyl at 40 mg/ml in a 1:5 dilution of sticker lowered the rate of carrot seedling emergence until day 13 and plant growth until day 28. oxamyl at 20 or 40 mg/ml in a 1:5 dilution of sticker on carrot seeds planted in m. hapla-infested muck ... | 1990 | 19287706 |
| host range and ecology of isolates of pasteuria spp. from the southeastern united states. | isolates of pasteuria penetrans were evaluated for ecological characteristics that are important in determining their potential as biological control agents. isolate p-20 survived without loss of its ability to attach to its host nematode in dry, moist, and wet soil and in soil wetted and dried repeatedly for 6 weeks. some spores moved 6.4 cm (the maximum distance tested) downward in soil within 3 days with percolating water. the isolates varied greatly in their attachment to different nematode ... | 1990 | 19287753 |
| resistance in lycopersicon peruvianum to isolates of mi gene-compatible meloidogyne populations. | root-knot nematode resistance of f progeny of an intraspecific hybrid (lycopersicon peruvianum var. glandulosum acc. no. 126443 x l. peruvianum acc. no. 270435), l. esculentum cv. piersol (possessing resistance gene mi), and l. esculentum cv. st. pierre (susceptible) was compared. resistance to 1) isolates of two meloidogyne incognita populations artificially selected for parasitism on tomato plants possessing the mi gene, 2) the wild type parent populations, 3) four naturally occurring resistan ... | 1990 | 19287762 |
| plant-parasitic nematodes and fungi associated with root rot of peas on prince edward island. | eight commercial pea fields on prince edward island were sampled in june and july over a 2-year period (1986-87) to determine soil population densities and the incidence of nematodes and fungi associated with root rot of peas. root lesion nematodes (pratylenchus spp.) were the dominant endoparasitic nematodes recovered from roots and soil. low populations of the northern root-knot nematode (meloidogyne hapla) were also present. tylenchorhynchus spp. and paratylenchus spp. were recovered frequent ... | 1990 | 19287779 |
| plant-parasitic nematodes in maine agricultural soils. | in a survey of plant-parasitic nematodes associated with agricultural crops in nine maine counties, 744 soil samples from 26 potential host plants were analyzed between november 1987 and january 1989. the most commonly encountered nematode genus was pratylenchus, occurring in 85% of the samples from most crops, except blueberries and onions. pratylenchus penetrans and p. crenatus were found commonly as species mixtures, with p. penetrans composing 40-80% of the mixture. meloidogyne hapla was enc ... | 1990 | 19287791 |
| evaluation of cultivars, experimental lines and plant introduction collection of sainfoin for resistance to meloidogyne hapla chitwood. | stands of several cultivars and experimental lines of sainfoin (onobrychis viciifolia) were severely reduced (92% average loss) in a field naturally infested with meloidogyne hapla. stands of two alfalfa cultivars included in the test were unaffected. in studies conducted in the greenhouse with plants inoculated at the time of seeding, average mortality was 55% for sainfoin entries and 7% for ladak alfalfa. little mortality occurred when plants were inoculated after establishment. three months a ... | 1987 | 19290103 |
| nematode-degree days, a density-time model for relating epidemiology and crop losses in perennials. | the impact of meloidogyne hapla on alfalfa (medicago sativa) yield was described by a multiple point damage model as a function of current plant status, cumulative pest stress, and crop history. nematode-degree days (ndd(female symbol)), calculated on a physiologic time scale as total area under the adult female population density curve, were used to express m. hapla parasitism as cumulative nematode dosage. ndd(female symbol) increased exponentially over physiological time at rates relative to ... | 1987 | 19290114 |
| usefulness of egg assays in nematode population-density determinations. | 1987 | 19290117 | |
| interaction of ditylenchus dipsaci and meloidogyne hapla on resistant and susceptible plant species. | numbers ofditylenchus dipsaci or meloidogyne hapla invading ranger alfalfa, tender crop bean, stone improved tomato, ah-14 sugarbeet, yellow sweet clover, and wasatch wheat from single inoculations were not significantly different from numbers by invasion of combined inoculations. d. dipsaci was recovered only from shoot and m. hapla only from root tissue. combined inoculations did not affect reproduction of either d. dipsaci or m. hapla. d. dipsaci suppressed shoot growth of all species at 15-3 ... | 1987 | 19290168 |
| control of pratylenchus penetrans and meloidogyne hapla and yield response of alfalfa due to oxamyl seed treatments. | alfalfa (medicago sativa l. cv. saranac) seed were soaked for 20 minutes in water, acetone, or methanol containing 10 or 50 mg/ml of oxamyl (vydate l) or coated with a 2% aqueous cellulose solution containing the same amounts of oxamyl. seed were analyzed for oxamyl by hplc immediately after treatment and after 9 and 26 months of storage. oxamyl content of alfalfa seed did not decline after 26 months of storage. the effects of seed treatment on growth of alfalfa and nematode control were examine ... | 1987 | 19290170 |
| parasitism of woody ornamentals by meloidogyne hapla. | meloidogyne hapla is the dominant root-knot nematode found in tennessee woody ornamental nurseries. in greenhouse tests, m. hapla produced galls and formed egg masses on roots of abelia x grandiflora, comus florida, hydrangea paniculata grandiflora, photinia x fraseri, spiraea x bumalda, spiraea x vanhouttei, and viburnum carlesii. galls on h. grandiflora and v. carlesii were mostly large and fusiform. galls on c. florida were spherical and usually terminal, whereas those on the other species we ... | 1987 | 19290273 |
| influence of glomus fasciculatum and meloidogyne hapla on allium cepa in organic soils. | the influence of meloidogyne hapla and glomus fasciculatum on allium cepa (onion) grown in organic soil was evaluated under greenhouse conditions. in the absence of g. fasciculatum, m. hapla significantly retarded the growth of a. cepa cv. krummery special and msu 8155 x 826, but had no detrimental influence on downing yellow globe, spartan banner, or spartan sleeper. all five cultivars maintained populations of m. hapla, final root population densities of m. hapla associated with spartan banner ... | 1985 | 19294058 |
| population trends and vertical distribution of plant-parasitic nematodes associated with vitis labrusca l. in michigan. | nematode population trends and vertical distribution were monitored in a southwest michigan vineyard (vitis labrusca cv. concord) from 1976 through 1983. shallow (20 cm) and deep (90 cm) applications of 1,3-dichloropropene applied at 281 (shallow) plus 658 or 1,122 (deep) liters/ ha provided excellent control of xiphinema americanum, criconemella xenoplax, and meloidogyne hapla. populations of x. americanum remained below detectable levels for the entire 8-year experimental period where the fumi ... | 1985 | 19294066 |
| interrelationship of heterodera schachtii and meloidogyne hapla on tomato. | invasion of tomato (lycopersicon esculentum l.) roots by combined and sequential inoculations of meloidogyne hapla and a tomato population of heterodera schachtii was affected more by soil temperature than by nematode competition. maximum invasion of tomato roots, by m. hapla and h. schachtii occurred at 30 and 26 c, respectively. female development and nematode reproduction (eggs per plant) of m. hapla was adversely affected by h. schachtii in combined inoculations of the two nematode species. ... | 1985 | 19294113 |
| influence of glomus fasciculatum on meloidogyne hapla infecting allium cepa. | the impact of glomus fasciculatum on meloidogyne hapla associated with allium cepa was evaluated in two experiments. nematode density was not different in mycorrhizal and nonmycorrhizal plants 10 weeks after the joint inoculation of m. hapla and g. fasciculatum. differences in the age structure of m. hapla populations reared on mycorrhizal and nonmycorrhizat plants were noted. g. fasciculatum enhanced leaf and bulb growth of a. cepa in the absence of m. hapla, but did not affect plant weight whe ... | 1985 | 19294114 |
| influence of meloidogyne hapla on alfalfa yield and host population dynamics. | self-thinning in alfalfa, a dynamic process involving the progressive elimination of the weakest plants, was enhanced by meloidogyne hapla. alfalfa stand densities decreased exponentially with time and were reduced 62% (p = 0.05) in the presence of m. hapla. as stand densities decreased over time, mean plant weights increased at a rate 2.59 times faster in the absence of m. hapla. in a stepwise multiple regression analysis, 65% of the total variation in yield could be explained by changes in sta ... | 1985 | 19294119 |
| interaction of vesicular-arbuscular mycorrhizae and cultivars of alfalfa susceptible and resistant to meloidogyne hapla. | the interaction between vesicular-arbuscular mycorrhizal (vam) fungi and the root-knot nematode (meloidogyne hapla) was investigated using both nematode-susceptible (grasslands wairau) and nematode-resistant (nevada synthetic xx) cultivars of alfalfa (medicago sativa) at four levels of applied phosphate. mycorrhizal inoculation improved plant growth and reduced nematode numbers and adult development in roots in dually infected cultures of the susceptible cultivar. the tolerance of plants to nema ... | 1986 | 19294155 |
| differential reaction of alfalfa cultivars to meloidogyne hapla and m. chitwoodi populations. | meloidogyne hapla reproduced and suppressed growth (p < 0.05) of susceptible lahontan and moapa alfalfa at 15, 20, and 25 c. at 30 c, resistant nevada syn xx lost resistance to m. hapla. m. hapla invaded and reproduced on rhizobium meliloti nodules of lahontan and moapa, inducing giant cell formation and structural disorder of vascular bundles of nodules without disrupting bacteroids. at 15, 20, and 25 c a m. chitwoodi population from utah reproduced on lahontan, moapa, and nevada syn xx alfalfa ... | 1986 | 19294189 |