| intra-species dna polymorphism in the tobacco cyst-nematode complex (globodera tabacum) using aflp. | amplified fragment length polymorphism (aflp) was used to obtain information on the within-species genetic variability of the tobacco cyst-nematode (tcn) complex. aflp was found to be well suited to this type of study. the current classification of tcn was confirmed. results indicate that the globodera tabacum solanacearum group, believed to be restricted to the u.s.a., also occurs in mexico. the within-species variability of tcn is considerable. populations from mexico may form a new subgroup. ... | 2001 | 11768220 |
| induction patterns of an extensin gene in tobacco upon nematode infection. | when sedentary endoparasitic nematodes infect plants, they induce complex feeding sites within the root tissues of their host. to characterize cell wall changes induced within these structures at a molecular level, we studied the expression of an extensin gene (coding for a major structural cell wall protein) in nematode-infected tobacco roots. extensin gene expression was observed to be induced very early upon infection. this induction was weak, transient, and probably due to wounding during pe ... | 1993 | 12271052 |
| morphological and molecular identification of globodera pallida associated with potato in idaho. | the identity of a newly discovered population of pale potato cyst nematode globodera pallida associated with potato in eastern idaho was established by morphological and molecular methods. morphometrics of cysts and second-stage juveniles were generally within the expected ranges for g. pallida with some variations noted. the idaho population and paratype material from epworth, lincolnshire, england, both showed variations in tail shape, with bluntly rounded to finely pointed tail termini. compa ... | 2007 | 19259482 |
| early crop root destruction for management of tobacco cyst nematodes. | prompt tillage after crop harvest was investigated as a cultural control for the tobacco cyst nematode, globodera tabacum tabacum, on stalk-cut broadleaf cigar wrapper tobacco. stalk stumps and roots remaining after harvest were destroyed by tilling immediately or from 2 to 6 wk after harvest in field experiments over 4 yr. cyst nematode pf/pi ratios ranged from 0.65 to 1.62 when plants were tilled immediately after harvest and 1.13 to 5.88 when tillage was delayed. nematode population developme ... | 2008 | 19259515 |
| genetics of burley and flue-cured tobacco resistance to globodera tabacum tabacum. | genotypes of burley (cultivars b-21 and b-49), flue-cured (line va-81 and cultivar pd-4), and connecticut broadleaf (cultivar c9) tobacco (nicotiana tabacum) resistant (r) or susceptible (s) to the tobacco cyst nematode globodera tabacum tabacum were crossed. f1 progeny of burley and susceptible broadleaf were selfed and backcrossed to produce additional progeny for evaluation of resistance in greenhouse experiments. plants without adult female nematodes visible (x10 magnification) on the root s ... | 2002 | 19265905 |
| broadleaf tobacco yield loss in relation to initial globodera tabacum tabacum population density. | field microplot experiments were conducted from 1995 to 1998 to determine the relationship between fresh shoot weight of stalk-cut broadleaf and shade-grown cigar wrapper tobacco types (nicotiana tabacum l.) and initial density of globodera tabacum tabacum second stage juveniles (j2) per cm(3) soil. total shoot weight was negatively correlated with initial nematode densities of 12.3 to 747.3 j2/cm(3) soil (r = -0.53 and -0.70 for broadleaf and shade-grown tobacco, respectively). nonlinear damage ... | 2002 | 19265906 |
| effects of host resistance and temperature on development of globodera tabacum solanacearum. | penetration and development of juveniles of tobacco cyst nematode (globodera tabacum solanacearum) on a resistant (nc567) and a susceptible (k326) cultivar of flue-cured tobacco (nicotiana tabacum l.) were determined in root zone chamber experiments. more vermiform juveniles developed into a swollen shape at 22, 27, and 31 degrees c than at 17 degrees c. development of flask-shaped nematodes appeared to be similar across tested temperatures (17, 22, 27, and 31 degrees c). general patterns of pen ... | 2001 | 19266009 |
| effects of tobacco cyst nematode on growth of flue-cured tobacco. | the effects of infection by tobacco cyst nematode (globodera tabacum solanacearum) on growth of flue-cured tobacco cultivars nc 567 (resistant) and k 326 (susceptible) were evaluated in the field in 1993 and 1994. infection by g. t. solanacearum suppressed number of leaves, plant height, and fresh weight of leaves and feeder roots. correlations between weekly egg densities of g. t. solanacearum collected from soil and host growth during 11 weeks after transplanting (wat) were often inconsistent ... | 1999 | 19270904 |
| 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 |
| development of selected tobacco cyst nematode isolates on resistant and susceptible cultivars of flue-cured tobacco. | tobacco cyst nematode (globodera tabacum solanacearum) isolates were collected from 11 locations in virginia, 3 in north carolina, and 1 in maryland. isolates from each location were maintained and increased on flue-cured tobacco, nicotiana tabacum cv k326. plants of flue-cured tobacco cultivars k326 (susceptible) and nc567 (resistant) were each inoculated with 6,000 g. t. solanacearum eggs/plant. tests were conducted over one (6 weeks) or two (14 weeks) generations of the nematode. shoot and ro ... | 2000 | 19270950 |
| isolation of beta-1,4-endoglucanase genes from globodera tabacum and their expression during parasitism. | two beta-1,4-endoglucanase (egase) cdnas were isolated from globodera tabacum, the tobacco cyst nematode, and have been designated as gt-eng-1 and gt-eng-2. gt-eng-1 and gt-eng-2 encode precursor proteins with a predicted secretion signal sequence, cellulolytic catalytic domain, and a linker domain. the protein product gt-eng-1 contains an additional 95 amino acid carboxy terminal sequence with strong similarity to type ii cellulose binding domains. riboprobes and polyclonal antibodies raised to ... | 2000 | 19270961 |
| reproduction of globodera tabacum solanacearum in seven flue-cured tobacco-producing soils. | the tobacco cyst nematode (globodera tabacum solanacearum) continues to pose a serious threat to flue-cured tobacco production in virginia and nearby states. soils were sampled from five uninfested and two infested flue-cured tobacco-producing locations. twenty-three edaphic factors were characterized to determine if any were correlated with g. t. solanacearum reproduction. comparisons were also made between pasteurized and natural soils to determine if biological suppression of g. t. solanacear ... | 2000 | 19270999 |
| enhanced hatching of globodera tabacum solanacearum juveniles by root exudates of flue-cured tobacco. | stimulation of hatching of a tobacco cyst nematode (globodera tabacum solanacearum) by root exudates from resistant nc 567 and susceptible k 326 cultivars of flue-cured tobacco, nicotiana tabacum, was investigated. root exudates were collected by soaking seedlings in deionized water for 2 hours at 22 degrees c in the dark. fifteen mature and uniformly sized cysts were exposed at 15, 20, or 25 degrees c to undiluted root exudate, root exudate diluted 1:1 or 1:3 with deionized water, or deionized ... | 1997 | 19274185 |
| trap crops and population management of globodera tabacum tabacum. | tobacco, eastern black nightshade, and tomato were grown for 3 to 13 weeks to assess differences in invasion, development, and soil density of globodera tabacum tabacum (tobacco cyst nematode) in field plots and microplots over three seasons. tobacco cyst nematodes invaded roots of resistant and susceptible tobacco, nightshade, and tomato. nematode development was fastest in nightshade and slowest in tomato, and few adults developed in roots of nematode-resistant tobacco. soil populations of tob ... | 1996 | 19277140 |
| shade tobacco yield loss and globodera tabacum tabacum population changes in relation to initial nematode density. | field microplot experiments were conducted from 1987 to 1992 to determine the relationship between fresh weight leaf yield of shade tobacco (nicotiana tabacum) and initial density of globodera tabacum tabacum (encysted j2 per cm(3) soil). initial nematode densities of 0.1 to 1,097 j2/cm(3) soil were negatively correlated with leaf yield, total shoot weight, and normalized plant height 5 to 6 weeks after transplanting (r = -0.73, -0.73, and -0.52, respectively). nonlinear damage functions were us ... | 1995 | 19277269 |
| hatch and reproduction of globodera tabacum tabacum in response to tobacco, tomato, or black nightshade. | the effects of broadleaf tobacco, tomato, and black nightshade on juvenile hatch and reproduction of globodera tabacum tabacum were determined in laboratory and greenhouse experiments. root exudates from nightshade stimulated greater egg hatch than those from either 'rutgers' tomato or '86-4' tobacco. hatch was greater at higher proportions of root exudates for all three plant species. root exudates from plants greater than 3 weeks old stimulated more hatch than younger plants. no regression rel ... | 1995 | 19277303 |
| morphology of second-stage juveniles and males of globodera tabacum tabacum, g. t. virginiae, and g. t. solanacearum (nemata: heteroderinae). | morphological comparisons with light microscopy and scanning electron microscopy were made among second-stage juveniles (j2) and males of several isolates of the three subspecies of the tobacco cyst nematode complex, globodera tabacum sspp. tabacum, virginiae, and solanacearum. observations focused on the anterior region, (including head shape, lip pattern, and stylet morphology) and the tail region (including tail shape in j2 and spicules in males). the three subspecies could not be separated o ... | 1993 | 19279737 |
| morphometrics of globodera tabacum tabacum, g. t. virginiae, and g. t. solanacearum (nemata: heteroderinae). | a morphometric evaluation of second-stage juveniles (j2), males, females, cysts, and eggs of several isolates of the tobacco cyst nematode (tcn) complex, globodera tabacum tabacum (gtt), g. t. virginiae (gtv), and g. t. solanacearum (gts) is presented. morphometrics of eggs, j2, and males are considerably less variable than of females and cysts. no measurements of eggs and j2 are useful for identification of the three subspecies. distance from the median bulb and excretory pore to the head end i ... | 1993 | 19279753 |
| monoclonal antibodies to the esophageal glands and stylet secretions of heterodera glycines. | three monodonal antibodies (mabs) that bound to secretory granules within the subventral esophageal glands of second-stage juveniles (j2) of the soybean cyst nematode (scn), heterodera glycines, were developed from intrasplenic immunizations of a mouse with homogenates of scn j2. two mabs to the secretory granules within subventral glands and one mab to granules within the dorsal esophageal gland of scn j2 were developed by intrasplenic immunizations with j2 stylet secretions. stylet secretions, ... | 1994 | 19279890 |
| 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 |
| control of globodera tabacum solanacearum by alternating host resistance and nematicide. | the feasibility of alternating use of resistant vs. susceptible flue-cured tobacco cultivars to improve control of globodera tabacum subsp, solanacearum (tcn) was investigated at two virginia locations in 1984-86. post-harvest tcn population densities were reduced in each year of the study when fenamiphos was used with a tcn-resistant cultivar (nc 567), relative to susceptible cultivars (k 326 or mc 944). using nc 567 with fenamipbos also reduced preplant tcn population densities in the next gro ... | 1989 | 19287572 |
| chemical control of nematodes on flue-cured tobacco in brazil, canada, united states, and zimbabwe. | a survey was conducted in four major flue-cured tobacco producing countries to determine use of nematicides for control of plant-parasitic nematodes on flue-cured tobacco. included in the survey were scientists from brazil, canada, the united states, and zimbabwe. nematicides were used on 60-95% of the flue-cured tobacco crop in these regions. the choice of fumigant and nonfumigant nematicides, however, varied greatly as influenced by the edaphic factors, nematode species, and other pests presen ... | 1989 | 19287656 |
| effect of oxamyl on globodera tabacum population dynamics and shade tobacco growth and yield. | preplant soil applications of oxamyl to shade grown tobacco in globodera tabacum-infested field soil increased green leaf yields over untreated plots by 10.7 and 21.0% for 2.2 and 6.7 kg a.i. oxamyl/ha, respectively. green leaf yield was negatively correlated (r = -0.60, p = 0.04) with initial g. tabacum density, which ranged from 33 to 154 second-stage juveniles (j2)/cm(3) soil. numbers of g. tabacum j2 and developing juveniles and adults (j3-adults) per gram root were fewer in plants from oxam ... | 1990 | 19287775 |
| effects of soil fumigants and aldicarb on bacterial wilt and root-knot nematodes in potato. | preplant soil applications of oxamyl to shade grown tobacco in globodera tabacum-infested field soil increased green leaf yields over untreated plots by 10.7 and 21.0% for 2.2 and 6.7 kg a.i. oxamyl/ha, respectively. green leaf yield was negatively correlated (r = -0.60, p = 0.04) with initial g. tabacum density, which ranged from 33 to 154 second-stage juveniles (j2)/cm(3) soil. numbers of g. tabacum j2 and developing juveniles and adults (j3-adults) per gram root were fewer in plants from oxam ... | 1990 | 19287780 |
| control of globodera tabacum solanacearum by rotating susceptible and resistant flue-cured tobacco cultivars. | alternate planting of flue-cured tobacco cultivars resistant (nc 567 or speight g-80) or susceptible (k 326) to the tobacco cyst nematode (tcn) globodera tabacum ssp. solanacearum on 1-year or 2-year intervals was investigated in virginia in 1987-89. the tcn-resistant cultivars reduced tcn population densities compared with continuous planting of k 326. initial tcn egg densities in soil tended to be lower and yields of k 326 without fenamiphos were consistently higher when a resistant cultivar h ... | 1990 | 19287783 |
| tobacco resistance to globodera tabacum. | two flue-cured tobacco cultivars, va-81 and pd-4, resistant to globodera tabacum solanacearum were tested for resistance to g. tabacum in field and greenhouse experiments. a g. tabacum-susceptible broadleaf cultivar ct86-4 was used for comparison. in a greenhouse screening procedure, va-81 and pd-4 had, respectively, 1 of 24 and 0 of 24 plants with any cysts visible on the root systems. all 24 plants of ct86-4 had at least four g. tabacum cysts visible per plant. up to 80% of juveniles emerged f ... | 1988 | 19290308 |
| seasonal fluctuations of globodera tabacum solanacearum as estimated by two soil extraction techniques. | two soil extraction methods were compared to determine their efficiency in recovering cysts and juveniles of a tobacco cyst nematode, globodera tabacum solanacearum. the methods were equally efficient when extracting nematodes from soil samples seeded in the laboratory; however, there was a significant extraction method x month interaction when the methods were used to estimate field soil populations over 2 years. the centrifugal sugar flotation method recovered greater numbers of cysts when den ... | 1985 | 19294106 |
| effects of continuous cropping of resistant and susceptible cultivars on reproduction potentials of heterodera glycines and globodera tabacum solanacearum. | the reproductive potentials of heterodera glycines (mixture of races 3 and 4 and unidentified races) and a tobacco cyst nematode globodera tabacum solanacearum were studied in the field. the experiments involved four cultivars of soybean glycine max and four cultivars of nicotiana tabacum. the reproductive potential of the h. glycines population was high on essex and lee 74 soybean but low on forrest and bedford over the 3 years (1982-84) of continuous cropping. the reproductive potential of h. ... | 1986 | 19294194 |
| the promoter of the arabidopsis thaliana cel1 endo-1,4-beta glucanase gene is differentially expressed in plant feeding cells induced by root-knot and cyst nematodes. | summary transgenic tobacco and arabidopsis thaliana carrying the arabidopsis endo-1,4-beta-glucanase (ec 3.2.1.4) cel1 promoter fused to the beta-glucuronidase (gus) reporter gene were infected with the root-knot nematode, meloidogyne incognita, and either the tobacco cyst nematode, globodera tabacum (tobacco), or beet cyst nematode, heterodera schachtii (arabidopsis). cel1-driven gus expression was detected in cell elongation zones of noninfected plants and within feeding sites (giant-cells) in ... | 2004 | 20565607 |
| development of primetime-real-time pcr for species identification of soybean cyst nematode (heterodera glycines ichinohe, 1952) in north carolina. | soybean cyst nematode (scn) is an obligate, sedentary parasite that is a major pathogen of soybean and accounts for an estimated 1 billion dollars in production losses annually in the united states of america. this paper describes the development of a real-time pcr method for rapid, sensitive, species-specific and accurate identification of scn alone or on mixed populations with other nematodes in north carolina. the 83-bp dna fragment of primetime-real-time pcr was designed based on a 477-bp-sc ... | 2012 | 23481469 |
| biological and chemical induction of resistance to the globodera tabacum solanacearum in oriental and flue-cured tobacco (nicotiana tabacum l.). | the effects of acibenzolar-s-methyl (asm) and four combinations of plant growth-promoting rhizobacteria (pgpr) on the reproduction of a tobacco cyst nematode, globodera tabacum solanacearum, and growth of nicotiana tabacum (cv. k326 and xanthi) were tested under greenhouse and field conditions. the pgpr included combinations of bacillus subtilis a13 with b. pumilis inr7, b. pumilis se34, b. licheniformis in937b, or b. amyloliquefaciens in937a, respectively. among the four rhizobacterial combinat ... | 2009 | 22736815 |
| effects of ph gene-associated versus induced resistance to tobacco cyst nematode in flue-cured tobacco. | effects of the systemic acquired resistance (sar)-inducing compound acibenzolar-s-methyl (asm) and the plant-growth promoting rhizobacterial mixture bacillus subtilis a13 and b. amyloliquefaciens in937a (gb99+gb122) were assessed on the reproduction of a tobacco cyst nematode (tcn- globodera tabacum solanacearum) under greenhouse conditions. two sets of two independent experiments were conducted, each involving soil or root sampling. soil sample experiments included flue-cured tobacco cultivars ... | 2009 | 22736824 |
| intraspecific variability within globodera tabacum solanacearum using random amplified polymorphic dna. | random amplified polymorphic dna (rapds) were used to investigate the intraspecific variability among 19 geographic isolates of globodera tabacum solanacearum from eight counties in virginia and one county in north carolina. globodera tabacum tabacum, g. t. virginiae, and the mexican cyst nematode (mcn) were included as outgroups. six primers were used and 119 amplification products were observed. each primer yielded reproducible differences in fragment patterns that differentiated the isolates ... | 2004 | 19262823 |
| human influence on the dispersal and genetic structure of french globodera tabacum populations. | the dispersal abilities and the population genetic structure of nematodes living in soils are poorly known. in the present study, we have pursued these issues in the tobacco cyst nematode, globodera tabacum, which is responsible of significant yield reductions. nine microsatellites markers were used to explore the dispersal and genetic structure of 18 french g. tabacum populations. all the populations sampled belong to the "tabacum" subspecies and low level of gene flow was observed among g. tab ... | 2014 | 25086343 |
| low cryoprotectant concentrations and fast cooling for nematode cryostorage. | cryopreservation protocols based on slow freezing or vitrification often result in cell injury due to ice formation, cell dehydration and/or toxic concentrations of cryoprotectant (cpa). in this study, we present a cryopreservation technique based on low, non-toxic concentrations of cryoprotectants (≈ 2-4m) combined with a rapid cooling rate in the liquid nitrogen phase (-196°c). protocols for successfully cryopreserving the plant parasitic nematodes globodera tabacum tabacum, heterodera schacht ... | 2011 | 21524646 |
| morphology of females and cysts of globodera tabacum tabacum, g. t. virginiae, and g. t. solanacearum (nemata: heteroderinae). | detailed morphological comparisons with light and scanning electron microscopy were made of white females and cysts of several isolates of globodera tabacum sspp. tabacum (gtt), virginiae (gtv), and solanacearum (gts). observations focused on body shape, anterior region including head shape, lip pattern, stylet morphology, and the terminal area in females; and body shape and terminal area of cysts. the most useful characters to separate the three subspecies were forms of the female body, cyst, s ... | 1993 | 19279752 |
| 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 ... | 1992 | 19282988 |