| carbohydrate-recognition domains on the surface of phytophagous nematodes. | human red blood cells (hrbc) adhered to preparasitic second-stage juveniles (j2) of heterodera avenae, heterodera schachtii, meloidogyne javanica, pratylenchus mediterraneus, rotylenchulus reniformis, and tylenchulus semipenetrans over the entire nematode body. binding was conspicuously confined to the head and tail of longidorus cohni, xiphinema brevicolle, and xiphinema index. binding was ca2+ and mg2+ dependent. in contrast, hrbc did not adhere to anguina tritici, aphelenchoides subtenius, di ... | 1995 | 7895833 |
| involvement of rna2-encoded proteins in the specific transmission of grapevine fanleaf virus by its nematode vector xiphinema index. | the nepovirus grapevine fanleaf virus (gflv) is specifically transmitted by the nematode xiphinema index. to identify the rna2-encoded proteins involved in x. index-mediated spread of gflv, chimeric rna2 constructs were engineered by replacing the 2a, 2b(mp), and/or 2c(cp) sequences of gflv with their counterparts in arabis mosaic virus (armv), a closely related nepovirus which is transmitted by xiphinema diversicaudatum but not by x. index. among the recombinant viruses obtained from transcript ... | 2001 | 11878885 |
| the specific transmission of grapevine fanleaf virus by its nematode vector xiphinema index is solely determined by the viral coat protein. | the viral determinants involved in the specific transmission of grapevine fanleaf virus (gflv) by its nematode vector xiphinema index are located within the 513 c-terminal residues of the rna2-encoded polyprotein, that is, the 9 c-terminal amino acids of the movement protein (2bmp) and contiguous 504 amino acids of the coat protein (2ccp) [virology 291 (2001) 161]. to further delineate the viral determinants responsible for the specific spread, the four amino acids that are different within the ... | 2004 | 15003859 |
| a genetic linkage map of grape, utilizing vitis rupestris and vitis arizonica. | a genetic linkage map of grape was constructed, utilizing 116 progeny derived from a cross of two vitis rupestris x v. arizonica interspecific hybrids, using the pseudo-testcross strategy. a total of 475 dna markers-410 amplified fragment length polymorphism, 24 inter-simple sequence repeat, 32 random amplified polymorphic dna, and nine simple sequence repeat markers-were used to construct the parental maps. markers segregating 1:1 were used to construct parental framework maps with confidence l ... | 2004 | 15292989 |
| sensitive and reliable detection of grapevine fanleaf virus in a single xiphinema index nematode vector. | grapevine fanleaf virus (gflv) is specifically transmitted from plant to plant by the ectoparasitic nematode xiphinema index. a sensitive and reliable procedure was developed to readily detect gflv in a single viruliferous x. index, regardless of the nematode origin, i.e. greenhouse rearings or vineyard soils. the assay is based on bead milling to disrupt nematodes extracted from soil samples, solid-phase extraction of total nematode rnas, and amplification of a 555bp fragment of the coat protei ... | 2004 | 15488624 |
| characterization of a naturally occurring recombinant isolate of grapevine fanleaf virus. | the naturally occurring grapevine fanleaf virus (gflv) recombinant isolate a17b was recovered from its grapevine host by sap inoculation and serial passages onto gomphrena globosa, a pseudo local lesion herbaceous host, and chenopodium quinoa, a systemic herbaceous host, to characterize some of its biological properties. sequence analysis of the cp gene, in which a recombinational event was previously detected, demonstrated the genetic stability of recombinant isolate a17b over a 5-year period i ... | 2005 | 15968475 |
| genetic and qtl analysis of resistance to xiphinema index in a grapevine cross. | resistance to the dagger nematode xiphinema index has been an important objective in grape rootstock breeding programs. this nematode not only causes severe feeding damage to the root system, but it also vectors grapevine fanleaf virus (gflv), the causal agent of fanleaf degeneration and one of the most severe viral diseases of grape. the established screening procedures for dagger nematode resistance are time consuming and can produce inconsistent results. a fast and reliable greenhouse-based s ... | 2008 | 18004541 |
| isolate-specific detection of grapevine fanleaf virus from xiphinema index through dna-based molecular probes. | abstract tests with a real-time reverse transcription-polymerase chain reaction (rt-pcr) were performed on specimens of xiphinema index collected from the rhizosphere of grapevine fanleaf virus (gflv)-infected grapevines at palagiano, italy. a 1,157-bp fragment of the gflv rna-2 coat protein (cp) gene was amplified and sequenced. a fluorescent scorpion probe was designed to detect a highly conserved cp region. a second region with isolate-specific multiple nucleotide polymorphisms was used to de ... | 2005 | 18943119 |
| multiplex polymerase chain reaction identification of single individuals of the longidorid nematodes xiphinema index, x. diversicaudatum, x. vuittenezi, and x. italiae using specific primers from ribosomal genes. | abstract the species x. index, x. diversicaudatum, x. vuittenezi, and x. italiae are established (e) or putative (p) vectors of grapevine fanleaf virus (gflv) (e), arabis mosaic virus (e), grapevine chrome mosaic virus (p), and gflv (p) nepoviruses of grapevine, respectively. all four species are very closely related taxonomically and their low field densities make them difficult to identify from morphological and morphometrical diagnostic characters when only single or few individuals are detec ... | 2003 | 18943130 |
| spatial distribution of the dagger nematode xiphinema index and its associated grapevine fanleaf virus in french vineyard. | the nematode xiphinema index is, economically, the major virus vector in viticulture, transmitting specifically the grapevine fanleaf virus (gflv), the most severe grapevine virus disease worldwide. increased knowledge of the spatial distribution of this nematode, both horizontally and vertically, and of correlative gflv plant infections, is essential to efficiently control the disease. in two infested blocks of the bordeaux vineyard, vertical distribution data showed that the highest numbers of ... | 2008 | 18943213 |
| survival of xiphinema index in vineyard soil and retention of grapevine fanleaf virus over extended time in the absence of host plants. | abstract grapevine fanleaf virus (gflv) is transmitted specifically from grapevine to grapevine by the ectoparasitic root-feeding nematode xiphinema index. limited information is available on the survival of x. index in vineyard soil and on the retention of gflv by x. index over extended periods of time. we addressed these two issues by quantifying the numbers of living x. index recovered from soil samples that were collected in three naturally gflv-infected vineyards in france and subsequently ... | 2005 | 18943467 |
| nematode and grape rootstock interactions including an improved understanding of tolerance. | sixteen cultivars of grape were screened over a two-year period in the presence or absence of 10 different nematode populations. populations of meloidogyne spp., xiphinema index, and mesocriconema xenoplax developed more rapidly and caused greater damage than populations of x. americanum and tylenchulus semipenetrans. populations of mixed meloidogyne spp. having a history of feeding on grape were among the fastest developing populations. tolerance to nematode parasitism appeared to be based on d ... | 2006 | 19259534 |
| 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 |
| 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 |
| biotin-avidin elisa detection of grapevine fanleaf virus in the vector nematode xiphinema index. | the value of biotin-avidin (b-a) elisa for the detection of grapevine fanleaf virus (gflv) in xiphinema was estimated with field populations and greenhouse subpopulations. samples consisted of increasing numbers of adults ranging from 1 to 64 in multiples of two. tests with virus-free x. index populations reared on grapevine and fig plants as negative controls did not reveal a noticeable effect of the host plant. elisa absorbances of virus-free x. index samples were greater than corresponding ab ... | 1993 | 19279786 |
| a collagenolytic fungus, cunninghamella elegans, for biological control of plant-parasitic nematodes. | the root-galling index of tomatoes inoculated with meloidogyne javanica was decreased 70% when collagen was used as a soil amendment (0.1% w/w) and 90% when the amendment was supplemented with the collagenolytic fungus cunninghamella elegans. the root-galling index was reduced 80% when the fungus was homogenized in collagen culture medium and added to soil without collagen supplement. culture filtrates of the fungus c. elegans, grown on collagen as a single source of carbon and nitrogen, immobil ... | 1991 | 19283126 |
| influence of four nematodes on root and shoot growth parameters in grape. | two grape cultivars, susceptible french colombard and tolerant rubired, and four nematodes, meloidogyne incognita, pratylenchus vulnus, tylenchulus semipenetrans, and xiphinema index, were used to quantify the equilibrium between root (r) and shoot (s) growth. root and shoot growth of french colombard was retarded by m. incognita, p. vulnus, and x. index but not by t. semipenetrans. although the root growth of rubired was limited by all the nematodes, the shoot growth was limited only by x. inde ... | 1989 | 19287609 |
| characterization of sialyl and galactosyl residues on the body wall of different plant parasitic nematodes. | the plant parasitic nematodes helicotylenchus multicinctus, meloidogyne javanica, tylenchulus semipenetrans, and xiphinema index, differing in their host specificity and parasitic habits, were analyzed as to their cuticle surface sialyl, galaclosyl, and/or n-acetylgalactosaminyl residues. the procedure involved the selective oxidation of sialic acid and galactose/n-acetylgal-actosamine residues using periodate and galactose oxidase, respectively, to form reactive aldehyde groups. these functiona ... | 1982 | 19295671 |
| electron microscope characterization of carbohydrate residues on the body wall of xiphinema index. | the location of carbohydrate moieties on the outer cuticle of xiphinema index was examined by electron microcopy using several different reagents: a) the periodic acid-thiosemicarbazide-silver proteinate reaction was used as a general stain for carbohydrates. in sectioned material it stained the canal system and deeper layers of the cuticle as well as the outer surface, b) cationized ferritin at ph 2.5, which identifies carboxyl and sulfate groups, was used to identify sialic acid residues and a ... | 1983 | 19295842 |
| response of pinus ponderosa seedlings to stylet-bearing nematodes. | of 12 stylet-bearing nematodes used for inoculations, pratylenchus penetrans, p. brachyurus, p. vulnus, ditylenchus destructor, meloidogyne incognita, m. javanica, and m. hapla reproduced on pinus ponderosa, while xiphinema index, aphelenchus avenae, paratylenehus neoamblycephalus, tylenchulus semipenetrans, and macroposthonia xenoplax did not. p. vulnus, p. brachyurus, p. penetrans, a. avenae, d. destructor, t. semipenetrans, and p. neoamblycephalus significantly suppressed both the shoot and r ... | 1979 | 19300659 |
| effects of pratylenchus vulnus and xiphinema index singly and combined on vine growth of vitis vinifera. | inoculation of 'thompson seedless' grapevines with 500 xiphinerna index or 1,000 pratylenchus vulnus alone or in combination suppressed vine shoot and root growth under greenhouse conditions. pratytenchus vulnus caused greater stunting of roots than x. index. each nematode species inhibited top growth about equally. concomitant inoculations caused greater stunting of tops and roots than did inoculations of either nematode species alone. differences in growth between inoculated and control plants ... | 1976 | 19308243 |
| effect of grapevine fanleaf virus on the reproduction and survival of its nematode vector, xiphinema index thorne &allen. | studies on the virus-vector interaction between the grapevine fanleaf virus (gfv) and its nematode vector, xiphinema index, indicate the virus had no measurable effect on the rate of reproduction of its vector, but significantly influenced survnal of the nematodes. | 1969 | 19325663 |
| genetic structure and variability of virus populations in cross-protected grapevines superinfected by grapevine fanleaf virus. | recombination was assessed in a vineyard site in which grapevines cross-protected with mild strains ghu of grapevine fanleaf virus (gflv) or ta of arabis mosaic virus (armv) were superinfected with gflv field isolates following transmission by the nematode vector xiphinema index. the genetic structure and variability within rna2 of isolates from grapevines co-infected with gflv field isolates and either gflv-ghu or armv-ta were characterized to identify intra- and interspecies recombinants. sequ ... | 2009 | 19409944 |
| genetic signature of amphimixis allows for the detection and fine scale localization of sexual reproduction events in a mainly parthenogenetic nematode. | asexuality is an important mode of reproduction in eukaryotic taxa and has a theoretical advantage over sexual reproduction because of the increased ability to propagate genes. despite this advantage, hidden signs of cryptic sex have been discovered in the genomes of asexual organisms. this has provided an interesting way to address the evolutionary impact of sex in plant and animal populations. however, the identification of rare sexual reproduction events in mainly asexual species has remained ... | 2010 | 20102516 |
| transmission competency of single-female xiphinema index lines for grapevine fanleaf virus. | grapevine fanleaf virus (gflv) is vectored specifically from grapevine to grapevine by the ectoparasitic nematode xiphinema index. limited information is available on the vector competency of x. index populations from diverse geographical origins. we determined the transmissibility of two gflv strains showing 4.6% amino acid divergence within their coat protein (e.g., strains f13 and ghu) by seven clonal lines of x. index developed from seven distinct populations from the mediterranean basin (cy ... | 2010 | 20205542 |
| cloning and characterization of xir1, a locus responsible for dagger nematode resistance in grape. | the dagger nematode, xiphinema index, feeds aggressively on grape roots and in the process, vectors grapevine fanleaf virus (gflv) leading to the severe viral disease known as fanleaf degeneration. resistance to x. index and gflv has been the key objective of grape rootstock breeding programs. a previous study found that resistance to x. index derived from vitis arizonica was largely controlled by a major quantitative trait locus, xir1 (x. index resistance 1), located on chromosome 19. the study ... | 2010 | 20490447 |
| a stretch of 11 amino acids in the betab-betac loop of the coat protein of grapevine fanleaf virus is essential for transmission by the nematode xiphinema index. | grapevine fanleaf virus (gflv) and arabis mosaic virus (armv) from the genus nepovirus, family secoviridae, cause a severe degeneration of grapevines. gflv and armv have a bipartite rna genome and are transmitted specifically by the ectoparasitic nematodes xiphinema index and xiphinema diversicaudatum, respectively. the transmission specificity of both viruses maps to their respective rna2-encoded coat protein (cp). to further delineate the gflv cp determinants of transmission specificity, three ... | 2010 | 20519403 |
| impact of quillaja saponaria saponins on grapevine ecosystem organisms. | the control of grapevine pathogens is a rising concern in vitis vinifera culture. the current international trend is toward banning chemicals that are highly toxic to the environment and human workers, and adopting tighter regulations. we evaluated the impact of saponins on three kinds of organisms found in grapevine culture. the ectoparasitic nematode xiphinema index, the parasitic fungus botrytis cinerea and various yeast strains representative of the must fermentation population were incubate ... | 2011 | 21442351 |
| development of nine polymorphic microsatellite markers for the phytoparasitic nematode xiphinema index, the vector of the grapevine fanleaf virus. | we report isolation, characterization and cross-species amplification of nine microsatellite loci from the phytoparasitic nematode xiphinema index, the vector of grapevine fanleaf virus. levels of polymorphism were evaluated in 62 individuals from two x. index populations. the number of alleles varies between two and 10 depending on locus and population. observed heterozygosity on loci across both populations varied from 0.32 to 0.857 (mean 0.545). the primers were tested for cross-species ampli ... | 2009 | 21564611 |
| structural insights into viral determinants of nematode mediated grapevine fanleaf virus transmission. | many animal and plant viruses rely on vectors for their transmission from host to host. grapevine fanleaf virus (gflv), a picorna-like virus from plants, is transmitted specifically by the ectoparasitic nematode xiphinema index. the icosahedral capsid of gflv, which consists of 60 identical coat protein subunits (cp), carries the determinants of this specificity. here, we provide novel insight into gflv transmission by nematodes through a comparative structural and functional analysis of two gfl ... | 2011 | 21625570 |
| resistance of grape rootstocks to plant-parasitic nematodes. | candidate grape rootstocks were selected through a rigorous screening program initiated with important sources of resistance to meloidogyne pathotypes and to xiphinema index in muscadinia rotundifolia and vitis species native to north america. based on their rooting capability and horticultural characteristics, 200 candidates were selected from 5,000 progeny of multiple crosses between commercial grape rootstocks and wild grape species that exhibited resistance to nematodes. after a 15-year scre ... | 2012 | 23482972 |
| a draft genome sequence of pseudomonas veronii r4: a grapevine (vitis vinifera l.) root-associated strain with high biocontrol potential. | a new plant commensal pseudomonas veronii isolate (strain r4) was identified from a xiphinema index biocontrol screen. isolated from grapevine roots from vineyards in central chile, the strain r4 exhibited a slower yet equivalently effective nematicide activity as the well-characterized p. protegens cha0. whole genome sequencing of strain r4 and comparative analysis among the available pseudomonas spp. genomes allowed for the identification of gene clusters that encode putative extracellular pro ... | 2016 | 27777646 |
| nematicidal activity of fluensulfone against some migratory nematodes under laboratory conditions. | the fluoroalkenyl fluensulfone, known to have strong nematicidal activity against meloidogyne spp. (root-knot nematodes), was evaluated in vitro and in soil against the migratory nematodes bursaphelenchus xylophilus, aphelenchoides besseyi, aphelenchoides fragariae, ditylenchus dipsaci, pratylenchus penetrans, pratylenchus thornei and xiphinema index. | 2014 | 24452922 |
| top 10 plant-parasitic nematodes in molecular plant pathology. | the aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. however, care was taken to include researchers from as many parts of the world as possible when carrying out the survey. the top 10 list emerging from the s ... | 2013 | 23809086 |
| detection of nepovirus vector and nonvector xiphinema species in grapevine. | fanleaf degeneration is considered the most damaging viral disease of grapevine. the two major nepoviruses involved are grapevine fanleaf virus (gflv) and arabis mosaic virus (armv) which are respectively and specifically transmitted by the dagger nematodes xiphinema index and x. diversicaudatum. the methods described below are aimed at detecting four prevalent grapevine xiphinema species: the vector species previously mentioned and two nonvector species x. vuittenezi and x. italiae. | 2015 | 25981253 |
| exoenzymes and metabolites related to the nematicidal effect of rhizobacteria on xiphinema index thorne & allen. | to identify enzymes and metabolites in the rhizobacteria filtrates that have a nematicidal effect on xiphinema index and perform molecular characterization of the strains evaluated. | 2016 | 26541369 |
| local and systemic mycorrhiza-induced protection against the ectoparasitic nematode xiphinema index involves priming of defence gene responses in grapevine. | the ectoparasitic dagger nematode (xiphinema index), vector of grapevine fanleaf virus (gflv), provokes gall formation and can cause severe damage to the root system of grapevines. mycorrhiza formation by glomus (syn. rhizophagus) intraradices beg141 reduced both gall formation on roots of the grapevine rootstock so4 (vitis berlandieri×v. riparia) and nematode number in the surrounding soil. suppressive effects increased with time and were greater when the nematode was post-inoculated rather tha ... | 2012 | 22407649 |
| control of xiphinema index populations by fallow plants under greenhouse and field conditions. | the dagger nematode xiphinema index has a high economic impact in vineyards by direct pathogenicity and above all by transmitting the grapevine fanleaf virus (gflv). agrochemicals have been largely employed to restrict the spread of gflv by reducing x. index populations but are now banned. as an alternative to nematicides, the use of fallow plants between two successive vine crops was assessed. we selected plant species adapted to vineyard soils and exhibiting negative impact on nematodes and we ... | 2012 | 22376084 |
| phylogenetic analysis of nematodes of the genus pratylenchus using nuclear 26s rdna. | we used nucleotide sequences of the large subunit ribosomal genes (26s rdna) to examine evolutionary relationships among species of the genus pratylenchus (order: tylenchida, family: pratylenchidae), commonly known as root-lesion nematodes. ten species of pratylenchus were studied including, p. penetrans, p. crenatus, p. minyus, p. vulnus, p. thornei, p. musicola, p. coffeae, p. hexincisus, p. scribneri, and p. brachyurus. the species hirschmanniella belli, meloidogyne javanica, heterorhabditis ... | 1997 | 9007024 |
| preliminary study of the green algae chlorella (chlorella vulgaris) for control on the root-knot nematode (meloidogyne arenaria) in tomato plants and ectoparasite xiphinema indexin grape seedlings. | the alternative ecological methods require investigation of many organo-biological means for plant protection against dangerous root parasites such as root-knot nematode meloidogyne arenaria and some ectoparasites (xiphinema index). the bulgarian organic product - dry extract of green alga chlorella vulgaris ("the golden apple"-plamen barakov) is the latest product, which in comparative aspect gives the best results. series of laboratory and pot experiments are carried out with tomato (cv. bele ... | 2005 | 16628939 |
| nematicidal activity of allyl bromide and dibromo(nitro)methane under laboratory conditions. | restrictions on soil fumigants are prompting the development of new compounds for controlling nematodes, other soilborne pathogens and weeds. we evaluated the nematicidal activity of five bromine compounds against meloidogyne javanica in vitro, and tested the two most effective ones against pratylenchus penetrans and xiphinema index in vitro and in soil. | 2016 | 25754847 |
| soil temperature effects on the interaction of grape rootstocks and plant-parasitic nematodes. | resistance to meloidogyne spp. in commonly used resistant grape rootstocks is slightly compromised at soil temperatures above 27°c. newly released ucd-grn series rootstocks, which have broad nematode resistance, exhibit trace infections by meloidogyne spp. at elevated temperature. pathotypes of m. incognita and m. arenaria that are virulent on 'harmony' rootstock, as well as m. incognita race 3, which is avirulent on 'harmony', failed to produce egg masses on the ucd-grn series rootstocks and ot ... | 2013 | 23589660 |
| candidate nematicidal proteins in a new pseudomonas veronii isolate identified by its antagonistic properties against xiphinema index. | the nematode xiphinema index affects grape vines and transmits important viruses associated with fanleaf degeneration. pseudomonas spp. are an extensive bacterial group in which important biodegradation and/or biocontrol properties can occur for several strains in the group. the aim of this study was to identify new pseudomonas isolates with antagonist activity against x. index. forty bacterial isolates were obtained from soil and root samples from chilean vineyards. thirteen new fluorescent pse ... | 2017 | 27989999 |
| ultrastructure of modified root-tip cells in ficus carica, induced by the ectoparasitic nematode xiphinema index. | the migratory ectoparasitic root nematode xiphinema index, added to ficus carica seedlings in sterile agar culture, fed exclusively on the tips of the roots. as a response the tips started to swell and became transformed into terminal galls as long as feeding was continued. when the cytology of swollen root-tips was examined 24 h after the first nematode attack, necrotic cells, scattered singly or in small groups within the root apex, were found in ultrathin sections. these cells, whose protopla ... | 1980 | 7364882 |
| longidorus cretensis n. sp. (nematoda: longidoridae) from a vineyard infected with a foliar 'yellow mosaic' on crete, greece. | a description is provided of longidorus cretensis n. sp., a bisexual species associated with grapevines in crete, greece. the species is characterised by a body length of 6.3-8.7 mm, head flattened anteriorly and continuous with the body profile, amphids pocket-shaped and not bilobed, a posteriorly situated guide-ring, posteriorly situated oesophageal glands, and a tail bluntly rounded to hemispherical. xiphinema index was present throughout the vineyard, but l. cretensis n. sp. occurred only in ... | 2001 | 11252276 |