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polyploidy and parthenogenesis in the root-knot nematode meloidogyne arenaria. 196314079604
nematodes parasitic on forest trees: iii. reproduction on selected hardwoods.the host-parasite relationships of 13 species of plant parasitic nematodes and five species of hardwoods native to the southeastern united states were tested on greenhouse-grown tree seedlings for 6-10 months. criteria for parasitism were completion o f life cycle and population increase of nematodes. belonolaimus longicaudatus, helicotylenchus dihystera, scutellonema brachyurum and tylenchorhynchus claytoni parasitized and reproduced on three or more of the species tested. hoplolaimus galeatus ...197119322363
influence of concomitant pratylenchus brachyurus and meloidogyne spp. on root penetration and population dynamics.populations of pratylenchus brachyurus on cotton were increased significantly in the presence of either meloidogyne incognita or m. arenaria.this occurred with either simultaneous inoculation or prior invasion by m. incognita. p. brachyurus penetrated cotton roots previously invaded by, or simultaneously inoculated with, m. incognita, as well as, or better than, in the absence of m. incognita. prior invasion by m. incognita, however, suppressed p. brachyurus populations on tomato, while it had n ...197319319334
japanese hollies: intolerant hosts of meloidogyne arenaria in microplots.japanese hollies were itttolerant of meloidogyne arenaria in field microplot experiments. ilex crenata var. rotundifolia was relatively more tolerant than i. crenata var. convexa or i. crenata var. helleri. when m. arenaria was added at various itfitial population densities to soil containing plants of "helleri," "convexa," and "rotundifolia," respectively, 91, 75, and 25% were killed by the end of the third growing season. no control plants died during the same period. initial numbers of m. are ...197719305618
seed treatment as a means of preventing nematode damage to crop plants.a procedure for treating crop seeds with aqueous solutions of the systemic nematicide oxamyl is described. seedlings from treated seeds were more resistant to attack by parasitic nematodes. leachate from treated seeds reduced the number of free-living nematodes in the surrounding soil.197719305617
development of a soil-temperature data base on meloidogyne arenaria for a simulation model.models for the development rate and death rate of meloidogyne arenaria relative to temperature and time were developed to improve the predictive performance of a computer simulator. about 74% of the eggs hatched fairly rapidly, whereas the remainder hatched at a lower rate and appeared to be uninfluenced by temperature shock and root exudates. death rates of eggs were rapid at extremes of temperature (5 and 36 c) during the first week, because of sensitivity of younger eggs, and then declined an ...197819305811
modification of a computer simulation model for a plant-nematode system.new data on egg development and death rates, and refinements of logic concerning interaction of the nematode and host, were incorporated into a simulation model of a meloidogyne arenaria and grapevine system. simulations of field data improved but other areas of weakness in the model were discovered. two peaks in the egg population curve suggested that the nematode was able to complete two life cycles before host dormancy and declining temperatures limited physiological activity.197819305839
quantitative aspects of the development of meloidogyne arenaria larvae in grapevine varieties and rootstocks.the development and productivity of parasitic stages of meloidogyne arenaria were quantitatively defined in 14 varieties or rootstocks of grapevine. mean development to maturity was related linearly to the number of degree-hours above 10 c temperature experienced from the time of penetration in all cultivars in which nematode adulthood was achieved. averaged across varieties, 13,142 heat units were required for development of the mean individual to maturity. the standard deviation of the develop ...197919305553
peroxidase isozymes from meloidogyne spp. and their origin.two peroxidase isozymes (ef 0.43 and 0.53) were detected by electrophoretic analysis in homogenates of meloidogyne arenaria, m. hapla, m. javanica, and m. incognita females reared on tomato. no peroxidase isozymes were detected electrophoretically in homogenates of adult males, preparasitic larvae, or eggs. peroxidase isozymes from females reared on bean, eggplant, or tobacco differed from those from females reared on tomato. bean and eggplant populations had a single peroxidase isozyme each, re ...197919305520
plant-parasitic nematode distributions in an alfalfa field.a 7-ha alfalfa field (medicago saliva l. cv mesa sirsa) was sampled systematically on a 6 x 6-m grid by removing individual cores (2.54 cm diam) to a depth of 45 cm from each of the 1,936 grid intersections. the soil was mainly coarse-textured with a fine-textured streak running centrally, north to south. nematodes were extracted by a semiautomatic elutriator and sugar flotation-sieving technique. five plant-parasitic species were consistently present: meloidogyne arenaria, pratylenchus minyus, ...198019300685
sample optimization for five plant-parasitic nematodes in an alfalfa field.a data base representing nematode counts and soil weight from 1,936 individual soil cores taken from a 7-ha alfalfa field was used to investigate sample optimization for five plant-parasitic nematodes: meloidogyne arenaria, pratylenchus minyus, merlinius brevidens, helicotylenchus digonicus, and paratrichodorus minor. sample plans were evaluated by the accuracy and reliability of their estimation of the population and by the cost of collecting, processing, and counting the samples. interactive f ...198119300768
comparative studies on root invasion, root galling, and fecundity of three meloidogyne spp. on a susceptible tobacco cultivar.root invasion, root galling, and fecundity of meloidogyne javanica, m. arenaria, and m. incognita on tobacco was compared in greenhouse and controlled environment experiments. significantly more m. javanica than m. arenaria or m. incognita larvae were found in tobacco roots at 2, 4, and 6 d after inoculation. eight days after inoculation there were significantly more m. arenaria and m. javanica than m. incognita larvae. ten days after inoculation no significant differences were found among the t ...198119300745
enhancement of cylindrocladium crotalariae root rot by meloidogyne arenaria (race 2) on a peanut cultivar resistant to both pathogens.two populations of meloidogyne arenaria (race 2, incompatible on peanut) enhanced development of cylindrocladium black rot (cbr) on cbr-resistant peanut cv. nc 3033 in greenhouse factorial experiments. nematode populations 256 and 486 (0, 10(3), 10 eggs per 15-cm pot) were tested in all combinations with cylindrocladium crotalariae (0, 0.5, 5, 50 microsclerotia per cm(3) of soil). root-rot index increased in the presence of either population. positions but not slope values of inoculum density-di ...198119300770
interaction between meloidogyne arenaria and glomus fascicuqlatus in grape.root zones of grape (fitis vinifera cv thompson seedless) cuttings were infested with chlamydospores of glomus fasciculatus or eggs of meloidogyne arenaria or both. growth of grapevines was greatest in mycorrhizal (g. fasciculatus) plants. mycorrhizal development and growth of mycorrhizal and nonmycorrhizal plants were reduced in the presence of m. arenaria. at low initial nematode inoculum (pi) levels (approx. 200 eggs/plant), the presence of mycorrhizae enhanced plant growth during 1 yr, but n ...198119300722
identification of meloidogyne species on the basis of head shape and, stylet morphology of the male.head shape and stylet morphology of males of 90 populations of m. arenaria, m. hapla, m. incognita, and m. javanica from geographic regions of the world were compared by light microscopy (lm). in addition, stylets of one population each of m. arenaria, m. incognita, and m. javanica and three different chromosomal forms of m. hapla race a and two of race b were excised and examined with a scanning electron microscope (sem). differences among species occurred in both head and stylet morphology. he ...198119300797
effects of pangola,digitgrass on meloidogyne arenaria, m. javanica, and m. hapla. 198319295862
histopathology of selected cultivars of tobacco infected with meloidogyne species.rates of nematode penetration and the histopathology of root infections in fluecured tobacco cultivars 'mcnair-944,' 'speight g-28,' and 'nc-89' with either meloidogyne arenaria, m. incognita, m. hapla, or m. javanica were investigated. penetration of root tips by juveniles of all species into the m. incognita-resistant nc-89 and g-28 was much less than that on the susceptible mcnair-944. few juveniles of m. incognita were detected in resistant cultivars 7 and 14 days after inoculation. infectio ...198319295823
distributed egg production functions for meloidogyne arenaria in grape varieties and consideration of the mechanistic relationship between plant and parasite.nematode egg production rates, as mediated by environmental conditions and host status, are important determinants of population development. rates of egg production by meloidogyne arenaria varied from 0.48 to 1.0 egg per female per dd (degree days above 10 c) in different grape varieties. the length of the egg production period ranged from 550 to 855 dd where measurable, and was generally longer in those varieties where the production rate was slow. we hypothesize that if a successful infection ...198419295898
evaluation of morphological variability in meloidogyne arenaria.seven populations, representing cytological race a (triploid, 3n = 51-56) and the two host races (infective and noninfective on peanut) of meloidogyne arenaria were studied with light microscopy (lm) and scanning electron microscopy (sem). characteristics of root-knot nematodes, recently recommended as useful taxonomic traits, were reexamined among these populations, and their variability both within and between populations was ascertained. we found that stylet morphology of females and head and ...198519294123
host-parasite relationships of meloidogyne arenaria and m. incognita on susceptible soybean.pathogenicity and reproduction of single and combined populations of meloidogyne arenaria and m. incognita on a susceptible soybean (glycine max cv. davis) were investigated. significant galling and egg mass production were observed on roots of greenhouse-grown soybean inoculated with m. arenaria and m. incognita, in combination and individually. m. arenaria produced more galls and egg masses than m. incognita, whereas in combined inoculation with both nematode species, gall and egg production w ...198519294112
interactions between six warm-season legumes and three species of root-knot nematodes. 198519294109
morphological comparisons of host races 1 and 2 of meloidogyne arenaria from florida.morphometric comparisons of two populations each of races 1 and 2 of meloidogyne arenaria from tobacco, peanut, and soybean in different localities in florida showed no significant differences in any characters measured by light microscopy. thirteen morphometric characters of females, 22 of males, and 21 of infective second-stage juveniles were measured for each population. the stylet length in each population and in each life stage was the least variable character. proposed character additions ...198519294095
interrelationships of meloidogyne arenaria and m. incognita on tolerant soybean.reproduction of meloidogyne arenaria race 2 was excellent on centennial, govan, and kirby soybeans, the latter two of which have tolerance to this species. the m. incognita race 1 isolate reproduced poorly on centennial, especially at the higher of two temperature regimes. numbers of galls and egg masses of m. arenaria plus m. incognita in simultaneous equivalent infestations on centennial did not differ from sequential infestations in which m. arenaria was added first and m. incognita was added ...198619294149
genotypic differentiation of meloidogyne populations by detection of restriction fragment length difference in total dna.detection of ecori restriction fragment length differences in repetitive dna sequences permitted the rapid diagnosis, by genotype, of randomly selected populations of meloidogyne incognita, races 1, 2, 3, and 4; m. javanica; m. arenaria, races 1 and 2; and m. hapla, races a and b.198619294145
soybean yield as related to rates of 1,3-dichloropropene applied at planting for management of root-knot disease.1,3-dichloropropene (1,3-d) at rates of 17.2 to 51.6 liters/ha applied 3 days preplant or at planting significantly (p < 0.05) reduced the amount of galling on roots of soybean grown in sites infested with meloidogyne incognita or m. arenaria. populations of m. incognita second-stage juveniles at harvest were significantly (p < 0.05) reduced by all treatments. only the 51.6-liters/ ha treatments and a 3-day preplant 34.4-liters/ha application significantly reduced at-harvest juvenile infestation ...198619294212
sterol composition and ecdysteroid content of eggs of the root-knot nematodes meloidogyne incognita and m. arenaria.free and esterified sterols of eggs of the root-knot nematodes meloidogyne incognita races 2 and 3 and m. arenaria race 1 were isolated and identified by gas-liquid chromatography-mass spectrometry. the major sterols of eggs of each race were 24-ethylcholesterol (33.4-38.8% of total sterol), 24-ethylcholestanol (18.3-25.3%), 24-methylcholesterol (8.6-11.7%), 24-methylcholestanol (7.7-12.5%), and cholesterol (4.6-11.6%). consequently, the major metabolic transformation performed by meloidogyne fe ...198719290155
galling and yields of soybean cultivars grown in meloidogyne arenana-infested soil.field trials with 39 soybean cultivars and five breeding lines from public and private sources were conducted from 1982 through 1985 at sites infested with meloidogyne arenaria. nematode population densities and root-knot galling were measured for each soybean entry. all were efficient hosts for the nematode, and average juvenile numbers in the soil increased 5-50 x from planting to harvest. differences (p < 0.05) in galling were found among entries in each year. centennial, cobb, coker 368, hut ...198719290135
response of cowpea breeding lines and cultivars to meloidogyne incognita and m. arenaria.twenty-four cowpea breeding lines and four cultivars were tested for resistance to meloidogyne incognita in the greenhouse. gall and egg mass ratings indicated a range of responses from susceptible to highly resistant. five breeding lines - vs84-2, vs84-8, vs84-12, vs84-14, and vs84-22 - and the cultivar erectset had gall and egg mass ratings comparable to the m. incognita-resistant cultivar mississippi silver. all of these were also resistant to m. arenaria. significantly fewer m. incognita juv ...198719290274
host suitability of commercial corn hybrids to meloidogyne arenaria and m. incognita.the host suitability of 64 commercial corn hybrids for a meloidogyne arenaria race 2 population and a m. incognita race 4 population was determined in greenhouse experiments. 'northrup king 508' and 'pioneer brand 3147' maintained m. arenaria below and at the initial population level, respectively, indicating that these hybrids are relatively poor hosts for this species. rf values (final egg number/initial egg number) of the hybrids for m. arenaria ranged from 0.8 for northrup king 508 to 42.3 f ...198719290266
peanut-cotton rotations for the management of meloidogyne arenaria.the efficacy of 'deltapine 90' cotton (gossypium hirsutum) in rotation with 'florunner' peanut (arachis hypogaea) for the management of meloidogyne arenaria was studied for 2 years in a field in southeastern alabama. in 1985, m. arenaria juvenile populations in plots with cotton were 98% lower than in plots with peanut. peanut and cotton yields were increased by treatment with aldicarb (3.3 kg a.i./ha in a 20-cm-band) in 1985 but not in 1986. in 1986, peanut yields were highest and m. arenaria j ...198719290174
soybean response to a planting-time application of ethylene dibromide in a soil infested with meloidogyne incognita, m. arenaria, and heterodera glycines.a field study was conducted to evaluate one susceptible and six nematode-resistant soybean cultivars for their effects on seed yield, nematode populations, and response to a fumigant nematicide, ethylene dibromide. the soil was a sandy loam, and the field was infested with a mixture of meloidogyne incognita, m. arenaria, and heterodera glycines. soybean cultivars significantly affected yield and juvenile numbers of meloidogyne spp. but did not affect the h. glycinesjuvenile population. fumigatio ...198719290278
usefulness of egg assays in nematode population-density determinations. 198719290117
soybean response to ethylene dibromide in a soil infested with meloidogyne arenaria and heterodera glycines.one susceptible and six nematode-resistant soybean cultivars were evaluated in the field for their effects on seed yield, nematode populations, and response to the fumigant nematicide, ethylene dibromide. the soil was a loamy sand infested with meloidogyne arenaria and heterodera glycines. cultivars significantly affected yield and numbers of h. glycines but did not affect m. arenaria numbers. fumigation increased yield and reduced m. arenaria numbers but did not affect numbers of h. glycines. t ...198719290285
effects of aldicarb on nematodes, early season insect pests, and yield of soybean.the effects of aldicarb on soybean cyst (heterodera glycines) and root-knot (meloidogyne incognita and m. arenaria) nematode populations, early season insect pests and soybean (glycine max) yield were evaluated in five field experiments in northern and southern alabama. aldicarb significantly (p = 0.05) reduced nematode populations in only two cases: m. arenaria in centennial soybean in the wiregrass site and m. incognita in bedford soybean in a tennessee valley site. no significant difference ( ...198719290282
host suitability of grain sorghum cultivars to meloidogyne spp.grain sorghum cultivars (funk g-499gbr, funk g-611, funk g-522a, funk g-522dr, coker 7723, coker 7675, coker 7623, pioneer b815, pioneer 8222, pioneer 8272) were evaluated in the greenhouse for resistance to populations of meloidogyne incognita race 3, m. arenaria race 2, and m. javanica from south carolina, and m. arenaria race 1 from georgia. all the sorghum cultivars were poor hosts or nonhosts of meloidogyne spp. with fewer than 1 or 2 egg masses per root system in all cultivar x nematode co ...198819290305
weed hosts of meloidogyne arenaria and m. incognita common in tobacco fields in south carolina.thirty-two weed species common in south carolina and one cultivar of tobacco were evaluated as hosts of meloidogyne arenaria race 2 and m. incognita race 3 in the greenhouse. egg mass production and galling differed (p < 0.05) among weed species. chenopodium album, euphorbia maculata, and vicia villosa were good hosts of m. arenaria. amaranthus palmeri, rumex crispus, amaranthus hybridus, ambrosia artemisiifolia, lpomoea hederacea var. integriuscula, setaria lutescens, sida spinosa, portulaca ol ...198819290313
bahiagrass for the management of meloidogyne arenaria in peanut.bahiagrass (paspalum notatum) cultivars argentine, pensacola, and tifton-9 were non-hosts for meloidogyne arenaria, m. incognita, and heterodera glycines in a greenhouse experiment using field soil infested with these nematodes. the effect of pensacola bahiagrass in rotation with peanut (arachis hypogaea) on m. arenaria was studied in 1986 and 1987 in a field at the wiregrass substation near headland, alabama. each year soil densities of second-stage juveniles of m. arenaria, determined near pea ...198819290315
effect of crop rotation on soybean in a field infested with meloidogyne arenaria and heterodera glycines.the effect of previous crops--soybean (glycine max) or corn (zea mays)--and aldicarb (2.2 kg a.i./ha) on yield and nematode numbers at harvest for soybean cultivars with various combinations of nematode resistance was determined in a sandy loam soil infested with meloidogyne arenaria race 2 and heterodera glycines races 3 and 4 at elberta, alabama, in 1987. cultivars had an effect on yield and nematode numbers (p = 0.01), as did the interaction of previous crop and cultivar. the nematicide treat ...198819290314
potential of crops uncommon to alabama for management of root-knot and soybean cyst nematodes.vigna unguiculata, cassia fasiculata, and sesamum indicum did not support meloidogyne arenaria, m. incognita, or heterodera glycines race 4 in greenhouse studies with soils from peanut and soybean fields. fagopyron eseulentum, cyamopsis tetragonoloba, and cucurbita pepo were hosts to the two meloidogyne spp. but were nonhosts to h. glycines. meloidogyne arenaria and m. incognita galled but reproduced poorly in the roots of three types of amaranthus cruentus, and low densities of these two meloid ...198819290317
unusual sequences, homologous to 5s rna, in ribosomal dna repeats of the nematode meloidogyne arenaria.there are sequences homologous to 5s ribosomal rna in the ribosomal dna (rdna) repeats of the plant-parasitic nematode meloidogyne arenaria. this is surprising, because in all other higher eukaryotes studied to date, the genes for 5s rna are unlinked to and distinct from a tandem rdna repeat containing the genes for 18s, 5.8s, and 28s ribosomal rna. previously, only prokaryotes and certain "lower eukaryotes" (protozoa and fungi) had been found to have both the larger rrnas and 5s rrna represente ...19883138424
efficacy of fumigant and nonfurmigant nematicides for control of meloidogyne arenaria on peanut.three tests were conducted to evaluate the efficacy of fumigant and nonfumigant nematicides for control of meloidogyne arenaria race 1 on peanut. methyl bromide, 1,3-d, methyl isothiocyanate, and methyl isothiocyanate mixtures were applied 7 or 8 days preplant either broadcast or in-the-row. aldicarb, ethoprop, fenamiphos, and f5145 were applied at different rates and by different methods at-plant or at early flowering. of the 32 treatments evaluated, only seven resulted in yield increases (p = ...198819290312
soybean-peanut rotations for the management of meloidogyne arenaria.rotating soybean (glycine max cv. kirby) with peanut (arachis hypogaea cv. florunner) for managing meloidogyne arenaria race 1 was studied for 3 years (1985-87) in a field near headland, alabama. each year soybean plots had lower soil numbers of m. arenaria second-stage juveniles (j2) at peanut harvest than did plots in peanut monocnlture. peanut following either 1 or 2 years of soybean resulted in approximately 50% reduction in j2 soil population densities and a 14% (1-year soybean) or 20% (2-y ...198819290309
soybean response to two isolates of meloidogyne arenaria. 198819290218
effect of carbamate, organophosphate, and avermectin nematicides on oxygen consumption by three meloidogyne spp.second-stage juveniles (i2) of meloidogyne arenaria consumed more oxygen (p </= 0.05) than m. incognita j2, which in turn consumed more than m. javanica j2 (4,820, 4,530, and 3,970 mul per hour per g nematode dryweight, respectively). decrease in oxygen consumption depended on the nematicide used. except for aldicarb, there was no differential sensitivity among the three nematode species. meloidogyne javanica had a greater percentage decrease (p </= 0.05) in oxygen uptake when treated with aldic ...198919287640
screening subterranean clover (trifolium spp.) germplasm for resistance to meloidogyne species.this study was conducted to identify lines of subterranean clover (trifolium spp.) with resistance to meloidogyne arenaria (neal, 1989) chitwood, 1949, race 1; m. incognita (kofoid and white, 1919) chitwood, 1949, race 3; and m. javanica (treub, 1885) chitwood, 1949. a collection of 134 subterranean clover lines was evaluated and all had intermediate to high susceptibility. root galling was negatively correlated with both seed and dry matter yields. soil fumigation significantly reduced the nema ...198919287623
host suitability of soybean cultivars for meloidogyne incognita and m. arenaria.the suitability of five maturity group (mg) iii and five mg iv soybean, glycine max, cultivars as hosts for meloidogyne incognita and m. arenaria was evaluated in a greenhouse. 'forrest', a mg v cultivar, was used as the standard of comparison for m. incognita resistance. with m. incognita, root-gall and egg-mass indices and reproductive factors for 'asgrow 3307', 'ffr 398', and 'pioneer 9442' were comparable with those found on forrest. meloidogyne arenaria reproduction was lower (p </= 0.05) o ...198919287669
resistance to meloidogyne arenaria in arachis spp. germplasm.field and greenhouse evaluations of 116 wild arachis spp. genotypes demonstrated the presence of resistance to reproduction of the root-knot nematode meloidogyne arenaria race 1. resistance in greenhouse tests was based on test lines having </= 2.5% of the number of eggs per gram of roots as did the susceptible a. hypogaea cv. tamnut 74. in field tests, resistant genotypes were identified on the basis of having lower (p = 0.05) final nematode population densities than did tamnut 74. resistance w ...198919287667
suitability of small grains as hosts of meloidogyne species.seven cultivars of wheat, five of oat, one of rye, and four of barley were tested as hosts for meloidogyne incognita, m. javanica, or m. arenaria under greenhouse conditions where soil temperature ranged from 21 to 34 c. reproduction rates of all nematode species were high on all cultivars, except m. javanica and m. arenaria on 'brooks' and 'florida 501' oat. meloidogyne incognita and m. javanica produced more eggs on roots of 'rutgers' tomato than on cultivars of wheat, oat, rye, or barley.198919287666
effects of root-knot nematodes on areca catechu.no root galling or egg mass formation was noted on betel palm (areca catechu) 3 or 9 months after inoculation with meloidogyne arenaria, m. hapla, m. incognita races 1 and 3, or m. javanica. compared with uninoculated controls, a reduction (p </= 0.05) in fresh root weight was noted after 3 months with m. incognita race 1 but not with other species or races, no differences (p </= 0.05) in root weight between controls and inoculated plants were observed at 9 months, nor were any differences found ...198919287679
crops uncommon to alabama for the management of meloidogyne arenaria in peanut.in a 1987 field study juveniles of meloidogyne arenaria assayed at the time of peanut harvest were almost undetectable in plots planted with american jointvetch (aeschynomene americana), castor bean (ricinus communis), partridge pea (cassia fasiculata), sesame (sesamum indicum), and cotton (gossypium hirsutum), whereas plots with peanut (arachis hypogaea) averaged 120 juveniles/100 cm(3) soil. application of aldicarb in peanut resulted in an average of 27 juveniles/100 cm(3) soil. in 1988 all pl ...198919287678
effects of bahiagrass and nematicides on meloidogyne arenaria on peanut.a field infested with meloidogyne arenaria and with a history of peanut yield losses was divided into two equal parts. one-half of the field (bahia site) was planted to bahiagrass in 1986 and maintained through 1987. the other half (peanut site) was planted to soybean in 1986 and peanut in 1987 with hairy vetch planted each fall as a cover crop. in 1988 identical nematicide treatments including 1,3-dichloropropene (1,3-d), aldicarb, and ethoprop were applied to the two sites, and the sites were ...198919287670
long-term effect of crop rotation on soybean in a field infested with meloidogyne arenaria and heterodera glycines.previous cropping sequence (corn-soybean vs. soybean-soybean) and aldicarb effects on soybean yield and nematode numbers at harvest for soybean cultivars with various combinations of nematode resistance were determined in 1988 in a sandy loam soil infested with meloidogyne arenaria race 2 and heterodera glycines races 3 and 4 at elberta, alabama. yield and nematode numbers differed among cultivars with 'leflore' having the highest yield. aldicarb treatment resulted in increased soybean yield but ...198919287680
plant-parasitic nematode acetylcholinesterase inhibition by carbamate and organophosphate nematicides.the sensitivity of acetylcholinesterases (ache) isolated from the plant-parasitic nematodes meloidogyne arenaria, m. incognita, and heterodera glycines and the free-living nematode caenorhabditis elegans to carbamate and organophosphate nematicides was examined. the ache from plant-parasitic nematode species were more sensitive to carbamate inhibitors than was ache from c. elegans, but response to the organophosphates was approximately equivalent. the sulfur-containing phosphate nematicides were ...199019287747
spring or fall fumigation for control of meloidogyne spp. on tobacco.tests were conducted in 1987-88 to compare the efficacy of spring or fall fumigant nematicide applications for control ofmeloidogyne arenaria and m. incognita on tobacco. chloropicrin, 1,3-d, methyl isothiocyanate, and a methyl isothiocyanate-l,3-d mixture were applied as row treatments. fenamiphos, fenamiphos + fensulfothion, or ethoprop were applied in the spring as nonfumigant nematicide standards. fumigant nematicides increased yields and reduced galling (p = 0.01) in all four tests. spring ...199019287773
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 ...199019287753
resistance of maize to meloidogyne arenaria and meloidogyne javanica.a diallel cross of eight maize, zea mays l., inbred lines was analyzed for reaction to two species of root-knot nematodes, meloidogyne arenaria (neal) chitwood and m. javanica (treub) chitwood. egg production following inoculation of f1 hybrid seedlings with nematode eggs was determined in a greenhouse experiment. data were analyzed using griffing's method 4, model i. general combining ability was a significant source of variation in egg production of both m. arenaria and m. javanica; specific c ...199024221114
evaluation of soybean cultivars for production in meloidogyne arenaria race 2-infested soil.field trials with 56 soybean cultivars and breeding lines from public and private sources were conducted from 1986 through 1988 at a site infested with meloidogyne arenaria race 2. differences (p < 0.05) among yields were found each year and yields were negatively correlated (p < 0.01) with root-knot nematode galling. all entries were galled and the highest-yielding entries, 'kirby' and 'coker 6738', were determined to have average yield reductions of 56% and 62%, respectively, when compared wit ...199019287790
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 ...199019287762
expression of resistance to meloidogyne arenaria in arachis batizocoi and a. cardenasii. 199019287741
expression of resistance to meloidogyne arenaria in arachis batizocoi and a. cardenasii. 199019287717
aggressiveness and reproduction of four meloidogyne arenaria populations on soybean.aggressiveness and reproduction differed among four geographical populations of m. arenaria on six soybean cultivars in field microplots. these differences were consistent over 3 years. the populations did not differ in virulence; i.e., population by cultivar interactions were not significant. perineal pattern morphology, the north carolina differential host test, chromosome counts of immature oocytes, and esterase phenotypes confirmed that the four populations were m. arenaria. three population ...199119283118
repeats and subrepeats in the intergenic spacer of rdna from the nematode meloidogyne arenaria.ribosomal dna (rdna) repeats of the plant-parasitic nematode meloidogyne arenaria are heterogeneous in size and appear to contain 5s rrna gene sequences. moreover, in a reca+ bacterial host, plasmid clones of a 9 kb rdna repeat show deletion events within a 2 kb intergenic spacer (igs), between 28s and 5s dna sequences. these deletions appear to result from a reduction in the number of tandem 129 bp repeats in the igs. the loss of such repeats might explain how rdna length heterogeneity, observe ...19912062313
size differences among root-knot nematodes on resistant and susceptible alyceclover genotypes.the influence of plant resistance on the size of individual root-knot nematodes was determined in greenhouse experiments. five genotypes of alyceclover were inoculated with second-stage juveniles of meloidogyne incognita race 3 or m. arenaria race 1. plants were harvested at selected intervals and stained for detection of the nematodes, which were dissected from the roots. length, width, and sagittal-sectional area of each animal were measured using an image-analysis system, and areas of nematod ...199119283120
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 ...199119283171
reaction of prunus rootstocks to meloidogyne incognita and m. arenaria in spain.prunus rootstocks were evaluated for their reaction to meloidogyne incognita and m. arenaria. most rootstocks were peach-almond hybrids of spanish origin. in one experiment three selections of garfi x nemared (g x n) and hansen-5 were highly resistant to m. incognita, but four other rootstocks were susceptible showing high galling indices and population increases. in two experiments with m. arenaria, the hybrid selections g x n nos. 1 and 9 were immune, gf-305 and hansen-5 were resistant, but ni ...199119283164
development of meloidogyne arenaria on peanut and soybean under two temperature cycles.florunner peanut and three soybean cultivars, centennial, gasoy 17, and wright, were inoculated with 48-hour age cohorts of meloidogyne arenari race 1 second-stage juveniles and placed in a growth chamber set to simulate early season (low temperature) and midseason (high temperature) conditions. percentages of the initial inoculum penetrating roots 4 and 8 days after inoculation were 2-3 times higher in soybean cultivars than in peanut; 25% on susceptible soybean and 9% on peanut. penetration an ...199119283157
comparisons of isozyme phenotypes in five meloidogyne spp. with isoelectric focusing.meloidogyne incognita race 1, m. javanica, m. arenaria race 1, m. hapla, and an undescribed meloidogyne sp. were analyzed by comparing isozyme phenotypes of esterase, malate dehydrogenase, phosphoglucomutase, isocitrate dehydrogenase, and alpha-glycerophosphate dehydrogenase. isozyme phenotypes were obtained from single mature females by isoelectric focusing electrophoresis. of these five isozymes, only esterase and phosphoglucomutase could be used to separate all five meloidogyne spp.; however, ...199119283155
characterization of species and races of the genus meloidogyne by dna restriction enzyme analysis.total dna of three species of meloidogyne spp., including four subspecific races of m. incognita, were digested separately with ecor i, cla iii, and hind iii and probed with (3)(2)p-labelled total genomic dna from m. incognita race 1 in southern hybridizations. short exposures of southern blots after hind iii digestion revealed patterns that were useful for separating the species. race differences were seen after longer exposures. the dna fragment patterns obtained were scanned with a laser dens ...199119283147
comparison of winter and spring soil fumigation with 1,3-d for the management of meloidogyne arenaria on peanut.field experiments were conducted in which the fumigant 1,3-d was applied at broadcast rates of 56 and 112 liters/ha during late winter and spring to two differing soil types in north florida. no advantage was demonstrated in applying the fumigant at the higher rate for the management of meloidogyne arenaria on peanut, and there was no disadvantage to applying a standard rate of the fumigant during winter as opposed to the standard practice of a 2-week preplant treatment. at one site, where rainf ...199119283185
meloidogyne arenaria populations on soybean.the distribution of meloidogyne spp. was determined in the piedmont and coastal plains soybean production areas of south carolina. meloidogyne arenaria, m. incognita, and m. javanica were found in six of seven counties surveyed, with some populations consisting of two or more species. because m. arenaria populations did not reproduce on peanut (arachis hypogaea cv. florunner), they were designated as host race 2. severity of root galling, shoot and root growth, seed yield, and nematode reproduct ...199119283177
characterization of potentially functional 5s rrna-encoding genes within ribosomal dna repeats of the nematode meloidogyne arenaria.in the plant-parasitic nematode meloidogyne arenaria, isolated rdna repeats show length heterogeneity, and are unusual in that they contain putative 5s ribosomal rna pseudogenes [vahidi et al., j. mol. evol. 27 (1988) 222-227]. potentially functional 5s rrna-encoding genes can also be identified in various rdna repeats, which appear to be tandemly organized in the genome.19911748312
characterization of acetylcholinesterase molecular forms of the root-knot nematode, meloidogyne.multiple molecular forms of acetylcholinesterase have been isolated and characterized from the root-knot nematodes meloidogyne arenaria and meloidogyne incognita. the forms of enzyme present in these 2 species are similar but not identical to those that occur in the free-living nematode caenorhabditis elegans. the 5 enzyme forms exhibit differential solubilities and can be classified into 3 classes, a, b, and c, based on substrate affinity, inhibitor and detergent sensitivity, and thermal inacti ...19911775164
race composition of meloidogyne incognita and m. arenaria populations in vegetable fields in uttar pradesh.a total of 1,256 populations of meloidogyne incognita and 442 populations of m. arenaria were collected from vegetables in eight districts of uttar pradesh, india. host differentials were used to identify the host race of each population. all four host races of m. incognita were present in six of the eight districts. in the other two districts, only host races 1, 2, and 4 were found. although frequencies of occurrence of the races differed among districts, races 1 and 2 comprised 62% of all m. i ...199119283172
rotations of soybean with tropical corn and sorghum for the management of nematodes.the relative efficacy of rotations of soybean with sorghum and tropical corn for nematode management was studied for 2 years in a field infested with root-knot (meloidogyne arenaria) and soybean cyst (heterodera glycines, race 14) nematodes. corn, sorghum, and soybean cv. kirby were planted in 1989, and in 1990 the same areas were planted with seven soybean cultivars with and without at-plant application ofaldicarb. corn and sorghum did not support h. glycines, but significant juvenile populatio ...199119283181
specific gravity of spores of pasteuria penetrans and extraction of spore-filled nematodes from soil.the specific gravity of spores of pasteuria penetrans collected from meloidogyne arenaria was found to be around 1.28. increasing the sucrose concentration used for the extraction of pratylenchus scribneri from a specific gravity of 1.14 to 1.26 led to the recovery of higher numbers of specimens filled with spores of pasteuria sp. (p </= 0.05). the numbers of spore-filled specimens of hoplolaimus galeatus recovered from field soil were not affected by the concentration of the sucrose solutions. ...199119283193
population development of pasteuria penetrans on meloidogyne arenaria.a microplot study on the influence of cropping sequences with peanut in summer and bare fallowed or cover crops of rye or vetch in winter on the population development of pasteuria penetrans was initiated in the spring of 1987. the number of spores of p. penetrans attached per second-stage juvenile of meloidogyne arenaria race 1 increased from 0.11 in the fall of 1987 to 7.6, 8.6, and 3.6 in the fall of 1989 in the rye, vetch, and fallowed plots, respectively. higher (p </= 0.05) levels of p. pe ...199119283094
penetration of susceptible and resistant tobacco cultivars by meloidogyne juveniles.rates of penetration of meloidogyne incognita, m. arenaria, and m. javanica into tobacco cultivars nc2326 (susceptible to all three species) and k399 (resistant to m. incognita) and a breeding line that had been selected for resistance to m. incognita were compared. meloidogyne incognita penetrated nc2326 rapidly during the first 24 hours after inoculation. numbers of m. incognita continued to increase gradually through the 14-day experiment. higher numbers of m. incognita were observed in the r ...199119283116
resistance in soybean cultivars from maturity groups v-viii to soybean cyst and root-knot nematodes.one hundred thirty-nine cultivars of soybean (glycine max) in maturity groups v, vi, vii, and viii were evaluated in a greenhouse for resistance to heterodera glycines races 3 and 14 and meloidogyne incognita, m. arenaria, and m. javanica. of the cultivars tested, 37% had resistance to h. glycines race 3 alone, 12% had resistance to both races 3 and 14, and 69% exhibited a moderate or high level of resistance to one or more of the meloidogyne spp. however, 24% were susceptible to each race of h. ...199119283166
cotton as a rotation crop for the management of meloidogyne arenaria and sclerotium rolfsii in peanut.the value of cotton (gossypium hirsutum cv. deltapine 90) in rotation with peanut (arachis hypogaea cv. florunner) for the management of root-knot nematode (meloidogyne arenaria) and southern blight (sclerotium rolfsii) was studied for 6 years in a field at the wiregrass substation in southeast alabama. peanut yields following either 1 or 2 years of cotton (c-p and c-c-p, respectively) were higher than those of peanut monoculture without nematicide [p(-)]. at-plant application of aldicarb to con ...199119283179
rotations of bahiagrass and castorbean with peanut for the management of meloidogyne arenaria.the relative value of 'hale' castorbean (ricinus communis) and 'pensacola' bahiagrass (paspalum notatum) as rotational crops for the management of meloidogyne arenaria and southern blight (sclerotium rolfsii) in 'florunner' peanut (arachis hypogaea) production was studied for 3 years in a field experiment in southeast alabama. peanut following 2 years of castorbean (c-c-p) yielded 43% higher than monocultured peanut without nematicide. at-plant application of aldicarb (30.5 g a.i./100 m row in a ...199119283180
metabolism of plant sterols by nematodes.parasitic nematodes do not biosynthesize sterols de novo and therefore possess a nutritional requirement for sterol, which must be obtained from their hosts. consequently, the metabolism of phytosterols by plant-parasitic nematodes is an important process with potential for selective exploitation. the sterol compositions of several species of plant-parasitic nematodes were determined by capillary gas chromatography-mass spectrometry and compared with the sterol compositions of their hosts. satur ...19911779708
pasteuria sp. parasitizing trophonema okamotoi in florida.two populations of trophonema okamotoi parasitized by pasteuria sp. were found on liquidambar styraciflua (sweetgum) and on an unidentified tropical grass in north-central florida. endospores of this pasteuria sp. attached to motile vermiform second-stage juveniles (j2) and males of t. okamotoi, but not to other developmental stages. sporangia and new endospores were produced only inside the bodies of swollen and sedentary third- and fourth-stage juveniles and females that developed in the host ...199219283199
separation and characterization of heterodera glycines acetylcholinesterase molecular forms.the composition and biochemical properties of acetylcholinesterases isolated from heterodera glycines were determined. heterodera glycines contains three separable ache molecular forms that can be grouped into two classes corresponding to classes a and c found in some other nematode species. the apparent lack of class b ache is unusual and may have significant behavioral ramifications. the class c enzyme isolated from h. glycines is similar to that from meloidogyne arenaria and m. incognita but ...199219283216
variability among populations of meloidogyne arenaria.variability in reproduction and pathogenicity of 12 populations of meloidogyne arenaria race 1 was evaluated on florunner peanut, centennial soybean, rutgers tomato, g70, k326, and mc944 tobacco, and carolina cayenne, mississippi nemaheart, and santanka pepper. differences among m. arenaria populations in rates of egg production 45 days after inoculation were observed for all cultivars except santanka pepper. differences among populations in dry top weights or fresh root weights were recorded on ...199219283016
effect of temperature on attachment, development, and interactions of pasteuria penetrans on meloidogyne incognita.the effect of temperature (10, 20, 25, 30, and 35 c) on attachment and development of pasteuria penetrans on meloidogyne arenaria race 1 was elevated in growth chambers. the greatest attachment rate of endospores of p. penetrans occurred on second-stage juveniles at 30 c. the bacterium developed more quickly within its host at 30 and 35 c than at 25 c or below. the development of the bacterium within the nematode female was divided into nine recognizable life stages, which ranged from early vege ...199219283029
the role of microbes associated with chicken litter in the suppression of meloidogyne arenaria.the role of microbes associated with chicken litter in the suppression of meloidogyne arenaria in amended soil was investigated. amended soil treatments were prepared, including combinations of sterile and nonsterile chicken litter and soil. microbial biomass in different treatments was compared by measuring carbon dioxide evolution. there was less co evolved in sterile litter than in nonsterile litter treatments. tomato seedlings cv. rutgers were transplanted into soil mixtures and inoculated w ...199219283030
crop rotation studies with velvetbean (mucuna deeringiana) for the management of meloidogyne spp.results from a greenhouse experiment at cabrils, spain, with two velvetbean (mucuna deeringiana) accessions (florida and mozambique) growing in sterilized sandy loam and inoculated with meloidogyne arenaria race 2, m. incognita race 1, and m. javanica revealed that the legume was not a host for these nematodes. in contrast, roots of 'clemson spineless' okra (hibiscus esculentum), 'summer crookneck' squash (cucurbita pepo), and 'davis' soybean (glycine max) were galled by all three root-knot nema ...199219283043
problems and strategies associated with long-term use of nematode resistant cultivars.plant-parasitic nematodes are obligate parasites, and planting cultivars that are highly resistant to these organisms places extensive selection pressure on the target species and affects nontarget nematodes as well. problems encountered with long-term planting of cultivars resistant to nematodes include shifts in nematode races or species and the occurrence of multiple species of nematodes within the same field. these problems can be alleviated to some extent when crop management is used to les ...199219282988
field evaluation of selected soybean cultivars for resistance to two races of meloidogyne arenaria.the soybean cultivars 'braxton' and 'kirby' were less susceptible to both races 1 and 2 of meloidogyne arenaria than 'centennial' and 'young', which were highly susceptible. soybean seed yields of resistant cultivars were greater (p = 0.05) than susceptible cultivars. reproduction of m. arenaria races 1 and 2 was significantly lower on less susceptible cultivars compared to highly susceptible cultivars. root galling, caused by m. arenaria, was 5-10 times greater on centennial and young than on l ...199219283054
field evaluation of susceptibility to meloidogyne arenaria in arachis hypogaea plant introductions.resistance to meloidogyne arenaria race 1 is not currently available in commercial peanut cultivars. moderate levels of resistance have been identified in arachis hypogaea plant introductions (pi) in previous greenhouse studies. the purpose of this work was to evaluate the effects of resistance in peanut pi on populations dynamics of m. arenaria in field plots. the pi designated as resistant in greenhouse studies had fewer m. arenaria in roots than the most susceptible pi. at midseason and at th ...199219283050
effects of root decay on the relationship between meloidogyne spp. gall index and egg mass number in cucumber and horned cucumber.a greenhouse study was conducted to determine if root necrosis had an effect on the relationship between root-knot nematode gall index and egg mass number. thirty-four cultigens of cucumis (14 accessions, 12 cultivars, and six breeding lines of c. sativus, and two accessions of c. metuliferus) were evaluated against four root-knot species (meloidogyne arenaria race 2, m. incognita race 1, m. incognita race 3, and m. javanica) measuring gall index, root necrosis, and egg mass number. root necrosi ...199219283049
a rapid and efficient method for the screening of acid phosphatase 1 in young tomato seedlings, and for the identification of root-knot nematode species using miniaturized polyacrylamide gel electrophoresis.a relatively rapid and highly sensitive miniaturized polyacrylamide gel electrophoresis technique is described for the analysis of certain isozymes from single cotyledons of tomato seedlings and from single females of the root-know nematode (meloidogyne spp.). homogenates from single tomato cotyledons (7, 14, 21, and 28 days old) were electrophoresed and stained for acid phosphatase 1 (aps 1) activity. cotyledons from plants of all the above age groups showed good aps 1 activity. nondestructive ...19921382970
damage functions for meloidogyne arenaria on peanut.microplot experiments were conducted in 1989 and 1990 to determine the relationship between yield of peanut (arachis hypogaea) and inoculum density ofmeloidogyne arenaria race 1. nine inoculum densities were used, ranging from 0-200 eggs/100 cm(3) soil (1989) or from 0-100 eggs/100 cm(3) (1990), and each density was replicated 10 times. in 1989, higher final densities (mean of 1,171 juveniles [j2]/100 cm(3) soil) were obtained in plots inoculated with 0.5 to 50 eggs/100 cm(3) soil than in plots ...199219283223
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); ( ...199219283222
a novel technique for infesting field sites with encapsulated eggs of meloidogyne spp.eggs of meloidogyne arenaria race 1 were encapsulated in calcium alginate for use as inoculum to infest peanut field plots. some eggs within the capsules remained viable up to 10 weeks after preparation. a field site was successfully infested at peanut planting and (or) 6 weeks later. dual applications of nematode inoculum (at planting and 6 weeks later) were superior to single applications (at planting or 6 weeks after planting). field-site infestation levels at the end of the first year were r ...199219283221
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 ...199219283211
genomic rflp analysis of meloidogyne arenaria race 2 populations.traditional morphological methods of meloidogyne identification have been unsuccessful in distinguishing three south carolina, usa meloidogyne arenaria race 2 populations-govan, pelion, and florence. these populations differ greatly in reproductive rate and aggressiveness on soybean hosts. total genomic dna from eggs of each population was digested with the restriction endonuclease eco ri and southern hybridization analyses were performed with single-copy and interspersed multi-copy cloned probe ...199219283197
host suitability of graminaceous crop cultivars for isolates of meloidogyne arenaria and m. incognita.twenty-two graminaceous plant cultivars were evaluated in the greenhouse for host suitability for three south carolina isolates of meloidogyne arenaria race 2 (ma-r2) designated as florence, govan, and pelion, a florida isolate of m. arenaria race 1 (ma-r1), and a south carolina m. incognita race 3. host suitability was determined by calculating egg mass index (emi) reproduction factor (rf) (final egg numbers/initial egg numbers), and number of eggs per gram fresh root. corn hybrids pioneer 3147 ...199319279853
summer cropping effects on the abundance of meloidogyne arenaria race 2 and subsequent soybean yield.a summer-planted crop of alyceelover significantly (p < 0.05) increased the soil abundance of meloidogyne arenaria race 2 juveniles by 3.7-fold when measured in the following spring. maize, sorghum, and soybean had no significant effects on residual nematode numbers over the same period. summer plantings of aeschynomene, cotton, hairy indigo, tespedeza, millet, peanut, and sorghum-sudangrass were as efficient as fallow in reducing root-knot nematode population levels. soybean yields (averaging 2 ...199319279844
morphometric evaluation of hypotriploid and triploid populations of meloidogyne arenaria.a morphometric comparison of seven hypotriploid populations with five pooled triploid populations of meloidogyne arenaria was made using standard descriptive statistics, stepwise discriminant analysis (sda), and cluster analysis. six morphometric characters of females, 14 of second-stage juveniles (j2), and 18 of males were measured for each population. useful differentiating characters included: body length in j2; stylet length in females and j2; stylet-knob dimensions in females and males; dor ...199319279751
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