WorldWideScience

Sample records for nematode meloidogyne partityla

  1. Integrated management of root-knot nematode (Meloidogyne ...

    African Journals Online (AJOL)

    Integrated management of root-knot nematode (Meloidogyne incognita) for tomato production and productivity. Bayuh Belay1* ... less gall formation, number of eggs per egg mass and final nematode population over the untreated control in the pot house experiment. ...... to Control Plant Pests. University of Idaho. Moscow ...

  2. Reproduction of root knot nematode (Meloidogyne incognita) on Bt ...

    African Journals Online (AJOL)

    SARAH

    2013-09-30

    Sep 30, 2013 ... ABSTRACT. Objective: The sedentary endoparasite Meloidogyne incognita is an important plant parasitic nematode that infects cotton causing significant yield losses. The objective of this study was to evaluate reproduction of M. incognita in Bt cotton (06Z604D), isoline (99M03) and HART 89M (local ...

  3. Transcriptome Analysis of Resistant and Susceptible Alfalfa Cultivars Infected With Root-Knot Nematode Meloidogyne incognita

    OpenAIRE

    Postnikova, Olga A.; Hult, Maria; Shao, Jonathan; Skantar, Andrea; Nemchinov, Lev G.

    2015-01-01

    Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute...

  4. First report of the root-knot nematode Meloidogyne marylandi on Turfgrasses in Israel

    NARCIS (Netherlands)

    Oka, Y.; Karssen, G.; Mor, M.

    2004-01-01

    In a turfgrass nursery in Arava, Israel, a population of root-knot nematodes was isolated from poorly growing Zoysiagrass (Zoysia japonica Steud.) with symptoms of foliar chlorosis and roots with very small, smooth galls and protruding egg masses. The isolated population (genus Meloidogyne) included

  5. Nematicidal activity of plant extracts against the root-knot nematode, Meloidogyne incognita

    NARCIS (Netherlands)

    Wiratno,; Taniwiryono, D.; Berg, van den J.H.J.; Riksen, J.A.G.; Rietjens, I.; Djiwanti, S.R.; Kammenga, J.E.; Murk, A.J.

    2009-01-01

    Nematicidal activity of extracts from plants was assayed against Meloidogyne incognita. In laboratory assays extracts from tobacco (Nicotiana tabacum L), clove (Syzygium aromaticum L), betelvine (Piper betle L), and sweet flag (Acorus calamus L) were most effective in killing the nematode, with an

  6. In vitro proteolysis of nematode FLPs by preparations from the free-living nematode Panagrellus redivivus and two plant-parasitic nematodes (Heterodera glycines and Meloidogyne incognita)

    Science.gov (United States)

    Proteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyne incognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the la...

  7. Effect of extracts from three plant species on nematode Meloidogyne incognita (Kofoid and White Chitwood

    Directory of Open Access Journals (Sweden)

    Tulio F. Solano Castillo

    2014-01-01

    Full Text Available Nematodes of Meloidogyne genus are a serious problem for tomato production in the province of Loja, Ecuador. Because of the negative side effects of chemical nematicides, to solve this problem it is necessary look for alternatives. This work aimed to study the effect of ethanolic extracts from Lonchocarpus nicou (Aubl.,Piscidia carthagenensis Jacq. and Thevetia peruviana (Pers. K. Schum., in Meloidogyne incognita control, “invitro ” and glasshouse conditions, on tomato plants. The extracts induced a significant mortality, “ in vitro”, on juveniles. This effect was related with the source and concentrations of the extracts. In tomato growing in glasshouse, it was observed an appreciable reduction in the root gall index and in the nematode populations in soil, related with the plant species and the concentration used, too.

  8. Development of a sweet cherry pepper line with resistance to the southern root-knot nematode Meloidogyne incognita

    Science.gov (United States)

    The southern root-knot nematode (Meloidogyne incognita) is a major pathogen of pepper (Capsicum spp.), causing significant yield losses in heavily infected plants. The N-gene confers resistance to M. incognita, and has been successfully used to mitigate nematode damage in specific pepper varieties f...

  9. Transcriptome analysis of resistant and susceptible alfalfa cultivars infected with root-knot nematode Meloidogyne incognita.

    Directory of Open Access Journals (Sweden)

    Olga A Postnikova

    Full Text Available Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp. are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute to pathogenesis and defense responses in alfalfa against these pests and specifically against RKN. In this work, we performed root transcriptome analysis of resistant (cv. Moapa 69 and susceptible (cv. Lahontan alfalfa cultivars infected with RKN Meloidogyne incognita, widespread root-knot nematode species and a major pest worldwide. A total of 1,701,622,580 pair-end reads were generated on an Illumina Hi-Seq 2000 platform from the roots of both cultivars and assembled into 45,595 and 47,590 transcripts in cvs Moapa 69 and Lahontan, respectively. Bioinformatic analysis revealed a number of common and unique genes that were differentially expressed in susceptible and resistant lines as a result of nematode infection. Although the susceptible cultivar showed a more pronounced defense response to the infection, feeding sites were successfully established in its roots. Characteristically, basal gene expression levels under normal conditions differed between the two cultivars as well, which may confer advantage to one of the genotypes toward resistance to nematodes. Differentially expressed genes were subsequently assigned to known Gene Ontology categories to predict their functional roles and associated biological processes. Real-time PCR validated expression changes in genes arbitrarily selected for experimental confirmation. Candidate genes that contribute to protection against M. incognita in alfalfa were proposed and alfalfa-nematode interactions with

  10. Transcriptome analysis of resistant and susceptible alfalfa cultivars infected with root-knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Postnikova, Olga A; Hult, Maria; Shao, Jonathan; Skantar, Andrea; Nemchinov, Lev G

    2015-01-01

    Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute to pathogenesis and defense responses in alfalfa against these pests and specifically against RKN. In this work, we performed root transcriptome analysis of resistant (cv. Moapa 69) and susceptible (cv. Lahontan) alfalfa cultivars infected with RKN Meloidogyne incognita, widespread root-knot nematode species and a major pest worldwide. A total of 1,701,622,580 pair-end reads were generated on an Illumina Hi-Seq 2000 platform from the roots of both cultivars and assembled into 45,595 and 47,590 transcripts in cvs Moapa 69 and Lahontan, respectively. Bioinformatic analysis revealed a number of common and unique genes that were differentially expressed in susceptible and resistant lines as a result of nematode infection. Although the susceptible cultivar showed a more pronounced defense response to the infection, feeding sites were successfully established in its roots. Characteristically, basal gene expression levels under normal conditions differed between the two cultivars as well, which may confer advantage to one of the genotypes toward resistance to nematodes. Differentially expressed genes were subsequently assigned to known Gene Ontology categories to predict their functional roles and associated biological processes. Real-time PCR validated expression changes in genes arbitrarily selected for experimental confirmation. Candidate genes that contribute to protection against M. incognita in alfalfa were proposed and alfalfa-nematode interactions with respect to resistance

  11. Differential Metabolic Profiles during the Developmental Stages of Plant-Parasitic Nematode Meloidogyne incognita

    Directory of Open Access Journals (Sweden)

    Parthiban Subramanian

    2017-06-01

    Full Text Available Meloidogyne incognita is a common root-knot nematode with a wide range of plant hosts. We aimed to study the metabolites produced at each stage of the nematode life cycle to understand its development. Metabolites of Meloidogyne incognita were extracted at egg, J2, J3, J4, and female stages and 110 metabolites with available standards were quantified using CE-TOF/MS. Analyses indicated abundance of stage-specific metabolites with the exception of J3 and J4 stages which shared similar metabolic profiles. The egg stage showed increased abundance in glycolysis and energy metabolism related metabolites while the J2 metabolites are associated with tissue formation, motility, and neurotransmission. The J3 and J4 stages indicated amino acid metabolism and urea cycle- related metabolites. The female stage was characterized with polyamine synthesis, antioxidant activity, and synthesis of reproduction related metabolites. Such metabolic profiling helps us understand the dynamic physiological changes related to each developmental stage of the root-knot nematode life cycle.

  12. Nematode pests threatening soybean production in South Africa, with reference to Meloidogyne

    Directory of Open Access Journals (Sweden)

    Hendrika Fourie

    2015-09-01

    Full Text Available The area planted to soybean in South Africa has increased by 54% since the 2009 growing season, mainly as a result of the increasing demand for protein-rich food and fodder sources. Moreover, the introduction of advanced technology, namely the availability of genetically modified herbicide tolerant soybean cultivars also contributed towards increased soybean production. The omnipresence of plant-parasitic nematodes in local agricultural soils, however, poses a threat to the sustainable expansion and production of soybean and other rotation crops. Meloidogyne incognita and M. javanica are the predominant nematode pests in local soybean production areas and those where other grain-, legume- and/or vegetable crops are grown. The lack of registered nematicides for soybean locally, crop production systems that are conducive to nematode pest build-ups as well as the limited availability of genetic host plant resistance to root-knot nematode pests, complicate their management. Research aimed at various aspects related to soybean-nematode research, namely, audits of nematode assemblages associated with the crop, identification of genetic host plant resistance in soybean germplasm to M. incognita and M. javanica, the use of molecular markers that are linked to such genetic resistance traits as well as agronomic performance of pre-released cultivars that can be valuable to producers and the industry are accentuated in this review. Evaluation of synthetically-derived as well as biological-control agents are also discussed as complementary management tactics. It is important that lessons learned through extensive research on soybean-nematode interactions in South Africa be shared with researchers and industries in other countries as they might experience or expect similar problems and/or challenges.

  13. Inoculum levels of Meloidogyne hispanica and M. javanica affect nematode reproduction, and growth of tomato genotypes

    Directory of Open Access Journals (Sweden)

    Carla M.N. MALEITA

    2013-01-01

    Full Text Available A pot experiment was conducted to determine the effects of three inoculum levels (2,500, 5,000 and 10,000 eggs/plant on the reproduction of Meloidogyne hispanica and M. javanica isolates and growth of the susceptible tomato genotypes Easypeel and Moneymaker, and genotypes Motelle and VFnt-Cherr, which possess the Mi-gene, at 25±2°C. sixty days after inoculation, roots were assessed for gall index (Gi, reproduction factor (Rf=final/initial population density and reproduction index (RI=Rf in the Mi-gene tomato plants/Rf in tomato Easypeel × 100. shoot and root lengths and fresh and dry root and shoot weights were also recorded. both species of Meloidogyne reproduced at all inoculum levels on all four tomato genotypes (4≤GI≤5 and 3.44≤Rf≤317.30. The M. javanica isolate, obtained from an infected potato field, was identified as natural and partially virulent to the Mi-gene (3.71≤RI≤20.19. This emphasizes the need for new sources of resistance to root-knot nematodes and for testing Mi-tomato plants for their susceptibility to local populations. Reproduction of M. javanica and M. hispanica on the resistant Motelle and VFNT-Cherr was significantly less than on the susceptible Easypeel and Moneymaker. VFNT-Cherr was more resistant than Motelle, which suggest an influence of the genetic background of the plants on the nematode response. For Easypeel and Moneymaker, there was a trend of decreased plant growth parameters with increasing inoculum level, irrespective of the nematode species, due to damage caused by the increasing number of nematodes that invaded plant roots. However, these values on Motelle and VFnt-Cherr remained relatively stable regarding shoot and total shoot plus root dry weight. the reproductive rate of M. javanica was greater than that of M. hispanica on all four genotypes tested, and tomato plants inoculated with M. hispanica had greater growth parameters. the resistance response of the Mi-tomato plants was independent

  14. A Novel Meloidogyne incognita Effector Misp12 Suppresses Plant Defense Response at Latter Stages of Nematode Parasitism

    Science.gov (United States)

    Xie, Jialian; Li, Shaojun; Mo, Chenmi; Wang, Gaofeng; Xiao, Xueqiong; Xiao, Yannong

    2016-01-01

    Secreted effectors in plant root-knot nematodes (RKNs, or Meloidogyne spp.) play key roles in their parasite processes. Currently identified effectors mainly focus on the early stage of the nematode parasitism. There are only a few reports describing effectors that function in the latter stage. In this study, we identified a potential RKN effector gene, Misp12, that functioned during the latter stage of parasitism. Misp12 was unique in the Meloidogyne spp., and highly conserved in Meloidogyne incognita. It encoded a secretory protein that specifically expressed in the dorsal esophageal gland, and highly up-regulated during the female stages. Transient expression of Misp12-GUS-GFP in onion epidermal cell showed that Misp12 was localized in cytoplast. In addition, in planta RNA interference targeting Misp12 suppressed the expression of Misp12 in nematodes and attenuated parasitic ability of M. incognita. Furthermore, up-regulation of jasmonic acid (JA) and salicylic acid (SA) pathway defense-related genes in the virus-induced silencing of Misp12 plants, and down-regulation of SA pathway defense-related genes in Misp12-expressing plants indicated the gene might be associated with the suppression of the plant defense response. These results demonstrated that the novel nematode effector Misp12 played a critical role at latter parasitism of M. incognita. PMID:27446188

  15. GAMMA IRRADIATION OF SUGAR BEET SEEDS INDUCED PLANT RESISTANCE TO ROOT-KNOT NEMATODE MELOIDOGYNE INCOGNITA

    International Nuclear Information System (INIS)

    ABD EL FATTAH, A.I.; KAMEL, H.A.; EL-NAGDI, W.M.A.

    2008-01-01

    The main objective of this study was to investigate the effect of irradiation of sugar beet seeds on the plant resistance to root-knot nematode Meloidogyne incognita infection in addition to some morphological parameters, biochemical components and root technological characters. Relative to control (non-irradiated seeds), the obtained data showed that, all doses except 10 Gy significantly increased root length of un inoculated plants and the most effective dose was 200 Gy. All doses significantly decreased root diameter except 50 and 100 Gy. The 10 and 400 Gy significantly reduced root fresh weight while 50, 100 and 200 Gy caused non-significant increase. All doses significantly increased root fresh weight/dry weight than control. There was non-significant effect on the morphological parameters of the plants germinated from gamma irradiated seeds and inoculated with Meloidogyne incognita. Total chlorophyll of seed irradiated and un inoculated plants were significantly reduced by all doses except 200 Gy. All doses of gamma radiation caused non-significant decrease in the total chlorophyll of the infected plants. In un inoculated plants, a significant reduction in the total phenol was occurred due to all doses of gamma radiation. In contrast, in inoculated plants, 10 and 25 Gy caused significant reduction in the total phenol while 50 and 400 Gy caused significant increase in the total phenol.Significant increase in sucrose % was observed due to 10 Gy in the un inoculated plants. The 400 Gy caused significant decrease while other doses caused non-significant decrease in the sucrose %. In the inoculated plants, 50, 100 and 400 Gy caused significant increase in sucrose %. All doses significantly increased total soluble salts percent (TSS %) of either inoculated or un inoculated plants. Purity % was increased by all doses in the inoculated plants.The number of galls and egg masses were reduced gradually by increasing gamma doses and 100 Gy caused the highest reduction 89

  16. Resistance to Southern Root-knot Nematode (Meloidogyne incognita) in Wild Watermelon (Citrullus lanatus var. citroides).

    Science.gov (United States)

    Thies, Judy A; Ariss, Jennifer J; Kousik, Chandrasekar S; Hassell, Richard L; Levi, Amnon

    2016-03-01

    Southern root-knot nematode (RKN, Meloidogyne incognita) is a serious pest of cultivated watermelon (Citrullus lanatus var. lanatus) in southern regions of the United States and no resistance is known to exist in commercial watermelon cultivars. Wild watermelon relatives (Citrullus lanatus var. citroides) have been shown in greenhouse studies to possess varying degrees of resistance to RKN species. Experiments were conducted over 2 yr to assess resistance of southern RKN in C. lanatus var. citroides accessions from the U.S. Watermelon Plant Introduction Collection in an artificially infested field site at the U.S. Vegetable Laboratory in Charleston, SC. In the first study (2006), 19 accessions of C. lanatus var. citroides were compared with reference entries of Citrullus colocynthis and C. lanatus var. lanatus. Of the wild watermelon accessions, two entries exhibited significantly less galling than all other entries. Five of the best performing C. lanatus var. citroides accessions were evaluated with and without nematicide at the same field site in 2007. Citrullus lanatus var. citroides accessions performed better than C. lanatus var. lanatus and C. colocynthis. Overall, most entries of C. lanatus var. citroides performed similarly with and without nematicide treatment in regard to root galling, visible egg masses, vine vigor, and root mass. In both years of field evaluations, most C. lanatus var. citroides accessions showed lesser degrees of nematode reproduction and higher vigor and root mass than C. colocynthis and C. lanatus var. lanatus. The results of these two field evaluations suggest that wild watermelon populations may be useful sources of resistance to southern RKN.

  17. Hospitability of ornamental and medicinal plants to root-knot nematode (Meloidogyne incognita race 2

    Directory of Open Access Journals (Sweden)

    Francisco José Carvalho Moreira

    2017-10-01

    Full Text Available The correct identification of species and genus of nematodes that affect a particular culture is of great importance to form a quantity of information that will be useful to laboratories for diagnosis and control of these pathogens. Because of the increase in the production of ornamental and medicinal plants in the of Cear. á State, the agricultural importance of the genus Meloidogyne and the scarcity of information on the hospitability this pathogen in these species, in that it was to evaluate the susceptibility testing of 30 species, and 20 ornamental (Antirrhimum majus, Gazania ringens, Carthamus tinctorius, Bryophyllum cayicinum, Ceasalpinia pulcherrima, Thumbergia alata, Petunia hibryda, Exacum affine, Catharanthus roseus, Opuntia sp., Sansevieria trifasciata, Asparagus densiflorus, Hibiscus mutabilis-roreus, Impatiens balsamiana, Celosia spicata, Antirrhimum sp., Dianthus chinensis, Zinnia elegans, Tagetes patula, Capsicum annuum and 10 medicinal (Peumus boldus, Ocimum gratissimum, Mentha arvensis var. piperascens, Mentha x Vilosa, Plectranthus amboinicus, Ocimum bassilicum, Rosmarinus officinalis, Cymbopogon citratus, Lippia alba, Cymbopogon winterianus. The test was conducted in a greenhouse, of the Phytosanitary Sector, Department of Plant Science, Federal University of Ceará. The inoculation was conducted with 4,000 eggs/J2 for pot. Evaluation of the plants gave to 60 days after inoculation. Evaluated is the reaction of the plants, measuring up: number of galls and eggs, egg mass index, reproduction factor and reduce the reproduction factor. From these variables it was classified the reaction of plants to the nematode by means of five criterions. Of ownership of the results, it was verified that of the ornamental plants only species T. patula didn’t presented galls in your root system. Concerning medicinal species M. vilosa, C. citrates, L. alba, C. winterianus and P. boldus showed no galls in their root systems. Thus, concluded

  18. Screening and Histopathological Characterization of Korean Carrot Lines for Resistance to the Root-Knot Nematode Meloidogyne incognita

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    Yunhee Seo

    2014-03-01

    Full Text Available In total, 170 carrot lines developed in Korea were screened for resistance to Meloidogyne incognita race 1 to select parental genetic resources useful for the development of nematode-resistant carrot cultivars. Using the gall index (GI, gall formation was examined on carrot roots inoculated with approximately 1,000 second-stage juveniles of the nematode 7 weeks after inoculation. Sixty-one carrot lines were resistant (GI ≤ 1.0, while the other 109 were susceptible (GI > 1.0 with coefficient of variance (CV of GI for total carrot lines 0.68, indicating low-variation of GI within the lines examined. The histopathological responses of two carrot plants from resistant and susceptible lines were examined after nematode infection. In susceptible carrots, giant cells formed with no discernible necrosis around the infecting nematodes. In the resistant carrot line, however, no giant cells formed, although modified cells were observed with extensive formation of necrotic layers through their middle lamella and around the infecting nematodes. This suggested that these structural modifications were related to hypersensitive responses governed by the expression of true resistance genes. Therefore, the Korean carrot lines resistant to the nematode infection are potential genetic resources for the development of quality carrot cultivars resistant to M. incognita race 1.

  19. Control Effect of Sudan Grass on Root-Knot Nematode, Meloidogyne incognita, in Cucumber and Lettuce Greenhouses

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    Hyeong-Hwan Kim

    2014-12-01

    Full Text Available The effect of biological control of the root-knot nematode, Meloidogyne incognita, on cucumber and lettuce was evaluated with green manure crop species in greenhouse. Nematicidal effect of sudan grass cultivation in cucumber greenhouse was comparable to that of chemical treatment with fosthiazate GR, showing the high activity of 88.6%. Sudan grass cultivation in lettuce greenhouse significantly reduced the number of M. incognita in soil, showing 93.5% of nematiidal activity. In addition, since growth of sudan grass was superior to other green manure crop species, it is considered that cultivation of sudan grass is proper to control M. incognita in greenhouse.

  20. Extracellular Protease of Pseudomonas fluorescens CHA0, a Biocontrol Factor with Activity against the Root-Knot Nematode Meloidogyne incognita

    OpenAIRE

    Siddiqui, Imran Ali; Haas, Dieter; Heeb, Stephan

    2005-01-01

    In Pseudomonas fluorescens CHA0, mutation of the GacA-controlled aprA gene (encoding the major extracellular protease) or the gacA regulatory gene resulted in reduced biocontrol activity against the root-knot nematode Meloidogyne incognita during tomato and soybean infection. Culture supernatants of strain CHA0 inhibited egg hatching and induced mortality of M. incognita juveniles more strongly than did supernatants of aprA and gacA mutants, suggesting that AprA protease contributes to biocon...

  1. Extracellular Protease of Pseudomonas fluorescens CHA0, a Biocontrol Factor with Activity against the Root-Knot Nematode Meloidogyne incognita

    Science.gov (United States)

    Siddiqui, Imran Ali; Haas, Dieter; Heeb, Stephan

    2005-01-01

    In Pseudomonas fluorescens CHA0, mutation of the GacA-controlled aprA gene (encoding the major extracellular protease) or the gacA regulatory gene resulted in reduced biocontrol activity against the root-knot nematode Meloidogyne incognita during tomato and soybean infection. Culture supernatants of strain CHA0 inhibited egg hatching and induced mortality of M. incognita juveniles more strongly than did supernatants of aprA and gacA mutants, suggesting that AprA protease contributes to biocontrol. PMID:16151170

  2. Meloidogyne lusitanica n. sp. (Nematoda: Meloidogynidae), a Root-knot Nematode Parasitizing Olive Tree (Olea europaea L.)

    OpenAIRE

    de O. Abrantes, Isabel M.; de A. Santos, M. Susana N.

    1991-01-01

    A root-knot nematode from Portugal, Meloidogyne lusitanica n. sp., is described and illustrated from specimens obtained from olive trees (Olea europaea L.). Females of the new species have a characteristic perineal pattern with medium to high trapezoidal dorsal arch with distinct punctuations in the tail terminus area. The excretory pore is located posterior to the stylet, about 1.5-2.5 stylet lengths from the anterior end. The stylet is 17.1 μm long with pear-shaped knobs. Males have a round...

  3. Understanding the interaction between an obligate hyperparasitic bacterium, Pasteuria penetrans and its obligate plant-parasitic nematode host, Meloidogyne spp.

    Science.gov (United States)

    Davies, Keith G

    2009-01-01

    Pasteuria penetrans is an endospore-forming bacterium, which is a hyperparasite of root-knot nematodes Meloidogyne spp. that are economically important pests of a wide range of crops. The life cycle of the bacterium and nematode are described with emphasis on the bacterium's potential as a biocontrol agent. Two aspects that currently prohibit the commercial development of the bacterium as a biocontrol agent are the inability to culture it outside its host and its host specificity. Vegetative growth of the bacterium is possible in vitro; however, getting the vegetative stages of the bacterium to enter sporogenesis has been problematic. Insights from genomic survey sequences regarding the role of cation concentration and the phosphorylation of Spo0F have proved useful in inducing vegetative bacteria to sporulate. Similarly, genomic data have also proved useful in understanding the attachment of endospores to the cuticle of infective nematode juveniles, and a Velcro-like model of spore attachment is proposed that involves collagen-like fibres on the surface of the endospore interacting with mucins on the nematode cuticle. Ecological studies of the interactions between Daphnia and Pasteuria ramosa are examined and similarities are drawn between the co-evolution of virulence in the Daphnia system and that of plant-parasitic nematodes.

  4. Potential of Leguminous Cover Crops in Management of a Mixed Population of Root-knot Nematodes (Meloidogyne spp.).

    Science.gov (United States)

    Osei, Kingsley; Gowen, Simon R; Pembroke, Barbara; Brandenburg, Rick L; Jordan, David L

    2010-09-01

    Root-knot nematode is an important pest in agricultural production worldwide. Crop rotation is the only management strategy in some production systems, especially for resource poor farmers in developing countries. A series of experiments was conducted in the laboratory with several leguminous cover crops to investigate their potential for managing a mixture of root-knot nematodes (Meloidogyne arenaria, M. incognita, M. javanica). The root-knot nematode mixture failed to multiply on Mucuna pruriens and Crotalaria spectabilis but on Dolichos lablab the population increased more than 2- fold when inoculated with 500 and 1,000 nematodes per plant. There was no root-galling on M. pruriens and C. spectabilis but the gall rating was noted on D. lablab. Greater mortality of juvenile root-knot nematodes occurred when exposed to eluants of roots and leaves of leguminous crops than those of tomato; 48.7% of juveniles died after 72 h exposure to root eluant of C. spectabilis. The leaf eluant of D. lablab was toxic to nematodes but the root eluant was not. Thus, different parts of a botanical contain different active ingredients or different concentrations of the same active ingredient. The numbers of root-knot nematode eggs that hatched in root exudates of M. pruriens and C. spectabilis were significantly lower (20% and 26%) than in distilled water, tomato and P. vulgaris root exudates (83%, 72% and 89%) respectively. Tomato lacks nematotoxic compounds found in M. pruriens and C. spectabilis. Three months after inoculating plants with 1,000 root-knot nematode juveniles the populations in pots with M. pruriens, C. spectabilis and C. retusa had been reduced by approximately 79%, 85% and 86% respectively; compared with an increase of 262% nematodes in pots with Phaseolus vulgaris. There was significant reduction of 90% nematodes in fallow pots with no growing plant. The results from this study demonstrate that some leguminous species contain compounds that either kill root

  5. Overexpression of MIC-3 indicates a direct role for the MIC gene family in mediating Upland cotton (Gossypium hirsutum) resistance to root-knot nematode (Meloidogyne incognita)

    Science.gov (United States)

    Major quantitative trait loci (QTL) have been mapped to Upland cotton (Gossypium hirsutum L.) chromosomes 11 and 14 that govern the highly resistant phenotype in response to infection by root-knot nematode (RKN; Meloidogyne incognita Chitwood & White); however, nearly nothing is known regarding the ...

  6. A study of interaction between Verticillium wilt Verticillium dahliae and root-knot nematode Meloidogyne javanica in olive cultivars.

    Science.gov (United States)

    Saeedizadeh, Ayatollah; Kheiri, Ahmad; Zad, Javad; Etebarian, Hasan Reza; Bandani, Ali Reza; Nasiri, Mohammad Bagher

    2009-01-01

    Second stage juvenile (J2) of root-knot nematode, Meloidogyne javanica, and microsclerotia of verticillium wilt, Verticillium dahliae, were used as the source of inoculum for nematode and fungus respectively. One-year-old seedlings of olive cultivars, Zard, Roghani, Koroneiki and Manzanilla, were transplanted to pots containing 2000g of sterilized sandy loam soil. Experiment was conducted in completely randomized design with 32 treatments and five replications. Treatments were as follows: control, nematode alone, fungus alone and fungus + nematode. Pots were inoculated with (0, 2000, 3000, 4000) J2 of nematode and/or (10 no/g soil) microsclerotia of fungus according to the treatments. Experiment was terminated after 10 months and fallowing parameters were determined i.e., fresh weight of root and stem, number of galls and egg masses per root system, and percentage of incidence of symptom on aerial parts, browning of vascular tissue, decrease of seedling height and stem/root tissue colonization by fungus. Results showed that presence of nematode caused reduction on colonization of the fungus in the root and stem and vice versa i.e. presence of fungus caused reduction on number of galls and egg masses produced by the nematode. Severe fungus wilt on aerial parts of Manzanilla cultivar was observed when both pathogens were inoculated and mild fungus wilt was observed in fungus alone treatments of Koroneiki cultivar. Galling and egg mass production in root system were reduced in cvs Manzanilla, Zard, Roghani and Koroneiki, respectively (p Manzanilla, respectively (p < or = 0/05).

  7. Reduction of root-knot nematode, Meloidogyne javanica, and ozone mass transfer in soil treated with ozone.

    Science.gov (United States)

    Qiu, Jinya Jack; Westerdahl, Becky B; Pryor, Alan

    2009-09-01

    Ozone gas (O₃) is a reactive oxidizing agent with biocidal properties. Because of the current phasing out of methyl bromide, investigations on the use of ozone gas as a soil-fumigant were conducted. Ozone gas was produced at a concentration of 1% in air by a conventional electrical discharge O₃ generator. Two O₃ dosages and three gas flow rates were tested on a sandy loam soil collected from a tomato field that had a resident population of root knot nematodes, Meloidogyne javanica. At dosages equivalent to 50 and 250 kg of O₃/ha, M. javanica were reduced by 24% and 68%, and free-living nematodes by 19% and 52%, respectively. The reduction for both M. javanica and free-living nematodes was dosage dependent and flow rate independent. The rates of O₃ mass transfer (OMT) through three soils of different texture were greater at low and high moisture levels than at intermediate ones. At any one soil moisture level, the OMT rate varied with soil texture and soil organic matter content. Results suggest that soil texture, moisture, and organic matter content should be considered in determining O₃ dosage needed for effective nematode control.

  8. OPDA has key role in regulating plant susceptibility to the root-knot nematode Meloidogyne hapla in Arabidopsis

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    Cynthia Gleason

    2016-10-01

    Full Text Available Jasmonic acid (JA is a plant hormone that plays important roles in regulating plant defenses against necrotrophic pathogens and herbivorous insects, but the role of JA in mediating the plant responses to root-knot nematodes has been unclear. Here we show that an application of either methyl jasmonate (MeJA or the JA-mimic coronatine (COR on Arabidopsis significantly reduced the number of galls caused by the root-knot nematode Meloidogyne hapla. Interestingly, the MeJA-induced resistance was independent of the JA-receptor COI1 (CORONATINE INSENSITIVE 1. The MeJA-treated plants accumulated the JA precursor cis-(+-12-oxo-phytodienoic acid (OPDA in addition to JA/JA-Isoleucine, indicating a positive feedback loop in JA biosynthesis. Using mutants in the JA-biosynthetic pathway, we found that plants deficient in the biosynthesis of JA and OPDA were hyper-susceptible to M. hapla. However, the opr3 mutant, which cannot convert OPDA to JA, exhibited wild-type levels of nematode galling. In addition, mutants in the JA-biosynthesis and perception which lie downstream of opr3 also displayed wild-type levels of galling. The data puts OPR3 (OPDA reductase 3 as the branch point between hyper-susceptibility and wild-type like levels of disease. Overall, the data suggests that the JA precursor, OPDA, plays a role in regulating plant defense against nematodes.

  9. Transcriptome analysis of root-knot nematode (Meloidogyne incognita)-infected tomato (Solanum lycopersicum) roots reveals complex gene expression profiles and metabolic networks of both host and nematode during susceptible and resistance responses

    DEFF Research Database (Denmark)

    Shukla, Neha; Yadav, Rachita; Kaur, Pritam

    2017-01-01

    Root knot nematodes (RKNs, Meloidogyne incognita) are economically important endoparasites having a wide-host range. We have taken a comprehensive transcriptomic approach to investigate the expression of both tomato and RKN genes in tomato roots at five infection time intervals from susceptible p...

  10. Brassicaceous Seed Meals as Soil Amendments to Suppress the Plant-parasitic Nematodes Pratylenchus penetrans and Meloidogyne incognita1

    Science.gov (United States)

    Meyer, S. L. F.; Morra, M. J.

    2009-01-01

    Brassicaceous seed meals are the residual materials remaining after the extraction of oil from seeds; these seed meals contain glucosinolates that potentially degrade to nematotoxic compounds upon incorporation into soil. This study compared the nematode-suppressive ability of four seed meals obtained from Brassica juncea ‘Pacific Gold’, B. napus ‘Dwarf Essex’ and ‘Sunrise’, and Sinapis alba ‘IdaGold’, against mixed stages of Pratylenchus penetrans and Meloidogyne incognita second-stage juveniles (J2). The brassicaceous seed meals were applied to soil in laboratory assays at rates ranging from 0.5 to 10.0% dry w/w with a nonamended control included. Nematode mortality was assessed after 3 days of exposure and calculated as percentage reduction compared to a nonamended control. Across seed meals, M. incognita J2 were more sensitive to the brassicaceous seed meals compared to mixed stages of P. penetrans. Brassica juncea was the most nematode-suppressive seed meal with rates as low as 0.06% resulting in > 90% suppression of both plant-parasitic nematodes. In general B. napus ‘Sunrise’ was the least nematode-suppressive seed meal. Intermediate were the seed meals of S. alba and B. napus ‘Dwarf Essex’; 90% suppression was achieved at 1.0% and 5.0% S. alba and 0.25% and 2.5% B. napus ‘Dwarf Essex’, for M. incognita and P. penetrans, respectively. For B. juncea, seed meal glucosinolate-degradation products appeared to be responsible for nematode suppression; deactivated seed meal (wetted and heated at 70 °C for 48 hr) did not result in similar P. penetrans suppression compared to active seed meal. Sinapis alba seed meal particle size also played a role in nematode suppression with ground meal resulting in 93% suppression of P. penetrans compared with 37 to 46% suppression by pelletized S. alba seed meal. This study demonstrates that all seed meals are not equally suppressive to nematodes and that care should be taken when selecting a source

  11. On the species status of the root-knot nematode Meloidogyne ulmi Palmisano & Ambrogioni, 2000 (Nematoda, Meloidogynidae

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    Mohammed Ahmed

    2013-12-01

    Full Text Available The root-knot nematode Meloidogyne ulmi is synonymised with Meloidogyne mali based on morphological and morphometric similarities, common hosts, as well as biochemical similarities at both protein and DNA levels. M. mali was first described in Japan on Malus prunifolia Borkh.; and M. ulmi in Italy on Ulmus chenmoui W.C. Cheng. Morphological and morphometric studies of their holo- and paratypes revealed important similarities in the major characters as well as some general variability in a few others. Host test also showed that besides the two species being able to parasitize the type hosts of the other, they share some other common hosts. Our study of the esterase and malate dehydrogenase isozyme phenotypes of some M. ulmi populations gave a perfectly comparable result to that already known for M. mali. Finally, phylogenetic studies of their SSU and LSU rDNA sequence data revealed that the two are not distinguishable at DNA level. All these put together, leave strong evidences to support the fact that M. ulmi is not a valid species, but a junior synonym of M. mali. Brief discussion on the biology and life cycle of M. mali is given. An overview of all known hosts and the possible distribution of M. mali in Europe are also presented.

  12. Susceptibilidad de genotipos de Solanum spp. al nematodo causante del nudo radical Meloidogyne spp. (chitwood) Susceptibility of genotypes of Solanum spp. to the nematode causative of the root knot Meloidogyne spp. (chitwood)

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    Cristian Gelpud Chaves

    2011-01-01

    Full Text Available El cultivo del lulo (Solanum quitoense L.) presenta una disminución en su productividad, debido al ataque de patógenos como el nematodo del nudo radical Meloidogyne spp., en el Departamento de Nariño (Colombia), se han reportado incidencias cercanas al 79%, y pérdidas del 50%. En la presente investigación, se colectaron 45 genotipos de (Solanum quitoense L.) en los Departamentos de Nariño y Putumayo y 4 genotipos silvestres (S. mammosum, S. hirtum, S. marginatum y S. umbellatum) buscando fuentes de resistencia al nematodo. Se inocularon 9 plantas de cada genotipo de dos meses de edad con 10000 huevos de Meloidogyne spp., dejando tres testigos por cada material. Las variables evaluadas fueron: altura de planta, severidad, incidencia, peso fresco (tallo y raíz) y especies prevalentes de Meloidogyne spp. Se hizo una clasificación de genotipos mediante escala de resistencia y regresión entre la severidad y las demás variables para establecer el efecto de Meloidogyne spp. sobre los genotipos de planta. Los resultados mostraron 100% de incidencia del nematodo en todos los genotipos, 2.04% genotipos resistentes, 34.7% moderadamente resistentes, 42.8% moderadamente susceptibles, 18.3% susceptibles, y 2.04% altamente susceptibles. El genotipo SQbr05 resistente, no se vio afectado por la severidad, al contrario SQbc04 genotipo susceptible, mostró reducciones significativas en peso fresco de tallo y raíz, (R² = 0.71 y 0.98), el genotipo silvestre (S. mammosum) es altamente susceptible, Meloidogyne incognita presentó 55.31% de presencia. El genotipo SQbr05 es promisorio para ser evaluado en campo.The green orange (Solanum quitoense L.) crop has decreased in its productivity due to the pathogens attack such as the root knot nematode Meloidogyne spp. In the Nariño Department of Colombia, pest incidences near to 79% and losses of 50% have been reported. In this study, 45 genotypes of Solanum quitoense were collected in Nariño and Putumayo

  13. Fly ash effect on hatching, mortality and penetration of root-knot nematode (Meloidogyne incognita in pumpkin roots

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    Gufran Ahmad

    2016-09-01

    Full Text Available An experiment was conducted to observe the effect of fly ash on hatching, mortality and penetration of root-knot nematode (Meloidogyne incognita in pumpkin roots. For hatching experiment different fly ash-extract concentrations (5, 10, 20, 30, 40, and 50% were prepared. Hatching was significantly reduced in all concentrations, maximum being at 50% concentration. The mortality (% of juveniles was observed in 1, 2, 3, 4, 5, 6 and 7th days with different levels (5, 10, 20, 30, 40 and 50 % of fly ash-extract. All the levels were found harmful to juveniles. As the level was increased, the killing percentage of juveniles was also increased. Highest mortality was observed in 7th day with 50% level.For the penetration experiment, fly ash was mixed with soil to prepare different concentrations (5, 10, 20, 30, 40, and 50%. Seeds of pumpkin were grown in coffee cups filled with different mixtures. At two leaf stage, seedlings were inoculated with 2000 larvae. The penetrated larvae in roots were observed after 1, 2, 3, 4, 5, 6 and 7 days. Root penetration was found inversely proportional to concentration. Significant results in the suppression of nematode penetration were noted up to 40% concentration. However, none of the juveniles was penetrated at 50% concentration.International Journal of Environment Vol.5(3 2016, pp.66-73

  14. Genetic Mapping of Resistance to Meloidogyne arenaria in Arachis stenosperma: A New Source of Nematode Resistance for Peanut

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    Soraya C. M. Leal-Bertioli

    2016-02-01

    Full Text Available Root-knot nematodes (RKN; Meloidogyne sp. are a major threat to crops in tropical and subtropical regions worldwide. The use of resistant crop varieties is the preferred method of control because nematicides are expensive, and hazardous to humans and the environment. Peanut (Arachis hypogaea is infected by four species of RKN, the most damaging being M. arenaria, and commercial cultivars rely on a single source of resistance. In this study, we genetically characterize RKN resistance of the wild Arachis species A. stenosperma using a population of 93 recombinant inbred lines developed from a cross between A. duranensis and A. stenosperma. Four quantitative trait loci (QTL located on linkage groups 02, 04, and 09 strongly influenced nematode root galling and egg production. Drought-related, domestication and agronomically relevant traits were also evaluated, revealing several QTL. Using the newly available Arachis genome sequence, easy-to-use KASP (kompetitive allele specific PCR markers linked to the newly identified RKN resistance loci were developed and validated in a tetraploid context. Therefore, we consider that A. stenosperma has high potential as a new source of RKN resistance in peanut breeding programs.

  15. Expression of Arabidopsis genes AtNPR1 and AtTGA2 in transgenic soybean roots of composite plants confers resistance to root-knot nematode (Meloidogyne incognita)

    Science.gov (United States)

    Root-knot nematodes (RKN; Meloidogyne spp.) are among the most destructive of the plant parasitic nematodes, infecting almost all cultivated plants and resulting in yield losses of billions of dollars annually. NPR1 (nonexpresser of pathogenesis related genes 1, AtNPR1) plays a positive role in the ...

  16. Genomes of parasitic nematodes (Meloidogyne hapla, Meloidogyne incognita, Ascaris suum and Brugia malayi) have a reduced complement of small RNA interference pathway genes: knockdown can reduce host infectivity of M. incognita.

    Science.gov (United States)

    Iqbal, Sadia; Fosu-Nyarko, John; Jones, Michael G K

    2016-07-01

    The discovery of RNA interference (RNAi) as an endogenous mechanism of gene regulation in a range of eukaryotes has resulted in its extensive use as a tool for functional genomic studies. It is important to study the mechanisms which underlie this phenomenon in different organisms, and in particular to understand details of the effectors that modulate its effectiveness. The aim of this study was to identify and compare genomic sequences encoding genes involved in the RNAi pathway of four parasitic nematodes: the plant parasites Meloidogyne hapla and Meloidogyne incognita and the animal parasites Ascaris suum and Brugia malayi because full genomic sequences were available-in relation to those of the model nematode Caenorhabditis elegans. The data generated was then used to identify some potential targets for control of the root knot nematode, M. incognita. Of the 84 RNAi pathway genes of C. elegans used as model in this study, there was a 42-53 % reduction in the number of effectors in the parasitic nematodes indicating substantial differences in the pathway between species. A gene each from six functional groups of the RNAi pathway of M. incognita was downregulated using in vitro RNAi, and depending on the gene (drh-3, tsn-1, rrf-1, xrn-2, mut-2 and alg-1), subsequent plant infection was reduced by up to 44 % and knockdown of some genes (i.e. drh-3, mut-2) also resulted in abnormal nematode development. The information generated here will contribute to defining targets for more robust nematode control using the RNAi technology.

  17. Effect of Entomopathogenic Nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) on Meloidogyne mayaguensis Rammah and Hirschmann (Tylenchida: Meloidoginidae) Infection in Tomato Plants

    Science.gov (United States)

    Molina, J. P.; Dolinski, C.; Souza, R. M.; Lewis, E. E.

    2007-01-01

    Some studies suggest that entomopathogenic nematodes (EPN) affect plant-parasitic nematode populations. Here, the effects of live and dead IJ of Heterorhabditis bacteriophora JPM4, H. baujardi LPP7, Steinernema feltiae SN and S. carpocapsae All were evaluated against eggs and J2 of the plant-parasitic nematode Meloidogyne mayaguensis. According to treatment, 100 IJ were applied with 350 eggs, 350 J2 or 175 eggs + 175 J2 to tomato plants. Bioassays were conducted in March to May and repeated in September to November 2005. Both experiments lasted 9 weeks, and the variable evaluated was number of galls per plant. When eggs were used for infections in the first trial, plants exhibited lower gall number compared to control when live and dead H. baujardi IJ and live S. feltiae IJ were added (9.7, 4.5, 7.3 and 85.7 galls, respectively). In the second trial, live S. feltiae and S. carpocapasae IJ influenced gall formation compared to control (14.33, 14.57 and 168.02 galls, respectively). When J2 were used for infections, plants with live H. baujardi IJ presented less galls when compared to control in both trials (38.3 and 355.7 galls in the first trial and 145.2 and 326.2 in the second one, respectively). Infection with a mixture of J2 and eggs resulted in fewer galls than when live S. feltiae IJ were present in both trials, compared to control (38.3 and 44.2 galls vs. 275.3 and 192.2 galls, respectively). We conclude that H. baujardi and S. feltiae apparently may be inhibiting egg hatching and J2 infection. PMID:19259509

  18. Shifting from priming of salicylic acid- to jasmonic acid-regulated defences by Trichoderma protects tomato against the root knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Martínez-Medina, Ainhoa; Fernandez, Ivan; Lok, Gerrit B; Pozo, María J; Pieterse, Corné M J; Van Wees, Saskia C M

    2017-02-01

    Beneficial root endophytes such as Trichoderma spp. can reduce infections by parasitic nematodes through triggering host defences. Little is currently known about the complex hormone signalling underlying the induction of resistance. In this study, we investigated whether Trichoderma modulates the hormone signalling network in the host to induce resistance to nematodes. We investigated the role and the timing of the jasmonic acid (JA)- and salicylic acid (SA)-regulated defensive pathways in Trichoderma-induced resistance to the root knot nematode Meloidogyne incognita. A split-root system of tomato (Solanum lycopersicum) was used to study local and systemic induced defences by analysing nematode performance, defence gene expression, responsiveness to exogenous hormone application, and dependence on SA and JA signalling of Trichoderma-induced resistance. Root colonization by Trichoderma impeded nematode performance both locally and systemically at multiple stages of the parasitism, that is, invasion, galling and reproduction. First, Trichoderma primed SA-regulated defences, which limited nematode root invasion. Then, Trichoderma enhanced JA-regulated defences, thereby antagonizing the deregulation of JA-dependent immunity by the nematodes, which compromised galling and fecundity. Our results show that Trichoderma primes SA- and JA-dependent defences in roots, and that the priming of responsiveness to these hormones upon nematode attack is plastic and adaptive to the parasitism stage. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  19. Evaluation of biological nematicides on the control of root-knot nematode (Meloidogyne incognita Chitwood at protected crops house in tomato (Lycopersicon esculentum Mill.

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    Pedro Fidel Fuentes Chaviano

    2011-06-01

    Full Text Available This research was carried out on Tomato (Lycopersicon esculentum Mill. variety HA 3105 at the protected crops houses in Empresa Azucarera Melanio Hernández of Sancti Spiritus, located at the southwest of Tuinucú, from November 2009 to May 2010 with the objective of evaluating the effectiveness of biological nematicides on the control of the root-knot nematode, Meloidogyne incognita Chitwood. Three treatments were used: Agrocelhone, biological nematicide HeberNem and HeberNem + Trichoderma. Biological nematicides showed better results than Agrocelhone regarding the length of the leaf, the height of the plant, the yield of tomato and the control of nematodes HeberNem showed the best results in the control of the nematode, decreasing the infestation from degree V to degree II.

  20. Analysis of Gene expression in soybean (Glycine max roots in response to the root knot nematode Meloidogyne incognita using microarrays and KEGG pathways

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    Gamal El-Din Abd El Kader Y

    2011-05-01

    Full Text Available Abstract Background Root-knot nematodes are sedentary endoparasites that can infect more than 3000 plant species. Root-knot nematodes cause an estimated $100 billion annual loss worldwide. For successful establishment of the root-knot nematode in its host plant, it causes dramatic morphological and physiological changes in plant cells. The expression of some plant genes is altered by the nematode as it establishes its feeding site. Results We examined the expression of soybean (Glycine max genes in galls formed in roots by the root-knot nematode, Meloidogyne incognita, 12 days and 10 weeks after infection to understand the effects of infection of roots by M. incognita. Gene expression was monitored using the Affymetrix Soybean GeneChip containing 37,500 G. max probe sets. Gene expression patterns were integrated with biochemical pathways from the Kyoto Encyclopedia of Genes and Genomes using PAICE software. Genes encoding enzymes involved in carbohydrate and cell wall metabolism, cell cycle control and plant defense were altered. Conclusions A number of different soybean genes were identified that were differentially expressed which provided insights into the interaction between M. incognita and soybean and into the formation and maintenance of giant cells. Some of these genes may be candidates for broadening plants resistance to root-knot nematode through over-expression or silencing and require further examination.

  1. Resistência de porta-enxertos para pessegueiro e ameixeira aos nematóides causadores de galhas (Meloidogyne spp. Resistance of rootstock for peach tree and plum to root-knot nematodes (Meloidogyne spp.

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    José Carlos Fachinello

    2000-03-01

    Full Text Available O trabalho foi realizado com o objetivo de comparar o comportamento de cinco diferentes porta-enxertos para frutas de caroço em frente a duas espécies de nematóides do gênero Meloidogyne (Meloidogyne javanica e Meloidogyne incognita. O cultivar GF 677 foi obtido a partir do cultivo in vitro e os demais porta-enxertos a partir de sementes. Aos dois meses, as plântulas foram repicadas e inoculadas com uma mistura de Meloidogyne javanica e M. incognita aos 30, 60 e 70 dias após o plantio em canteiros incorporando-se 0,2kg de solo altamente infestado com os nematóides ao redor de cada planta. Ao final do experimento, avaliaram-se o desenvolvimento das plantas e o grau de infecção de cada cultivar. O grau de resistência dos cultivares foi estimado a partir do índice de galhas, obtido através de uma escala de grau ou nota, a qual varia de 0 a 5, em função do número de galhas ou ootecas. Os resultados obtidos demonstraram que o cultivar Okinawa não apresentou galhas no sistema radicular e na análise de crescimento foi superior aos demais cultivares. Os cultivares R-15-2 e Aldrighi foram considerados resistentes aos fitonematóides por apresentarem pequeno número de galhas no sistema radicular. Já o cultivar GF 677 apresentou maior número de galhas no sistema radicular, chegando a 126 galhas/g de raiz.The work was carried out with the objective of comparing the response of five different stone fruit rootstocks to two nematode species (Meloidogyne javanica and Meloidogyne incognita. The cultivar GF677, which was obtained from in vitro cultivation and the others rootstocks, were obtained from seedlings. Two month old plants were transplanted and inoculated with a mixture of both nematode species at 30, 60, 70 days after planting, by incorporating 0.2kg of highly infested soil around each cultivar. The development of the roststocks were evaluated at the end of the experiment. Number of galls, ranging from 0 to 5 was used to score the

  2. Nematicidal activity of mint aqueous extracts against the root-knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Caboni, Pierluigi; Saba, Marco; Tocco, Graziella; Casu, Laura; Murgia, Antonio; Maxia, Andrea; Menkissoglu-Spiroudi, Urania; Ntalli, Nikoletta

    2013-10-16

    The nematicidal activity and chemical characterization of aqueous extracts and essential oils of three mint species, namely, Mentha × piperita , Mentha spicata , and Mentha pulegium , were investigated. The phytochemical analysis of the essential oils was performed by means of GC-MS, whereas the aqueous extracts were analyzed by LC-MS. The most abundant terpenes were isomenthone, menthone, menthol, pulegone, and carvone, and the water extracts yielded mainly chlorogenic acid, salvianolic acid B, luteolin-7-O-rutinoside, and rosmarinic acid. The water extracts exhibited significant nematicidal activity against Meloidogyne incognita , and the EC50/72h values were calculated at 1005, 745, and 300 mg/L for M. × piperita, M. pulegium, and M. spicata, respectively. Only the essential oil from M. spicata showed a nematicidal activity with an EC50/72h of 358 mg/L. Interestingly, menthofuran and carvone showed EC50/48h values of 127 and 730 mg/L, respectively. On the other hand, salicylic acid, isolated in the aqueous extracts, exhibited EC50 values at 24 and 48 h of 298 ± 92 and 288 ± 79 mg/L, respectively.

  3. Multiple Modes of Nematode Control by Volatiles of Pseudomonas putida 1A00316 from Antarctic Soil against Meloidogyne incognita

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    Yile Zhai

    2018-02-01

    Full Text Available Pseudomonas putida 1A00316 isolated from Antarctic soil showed nematicidal potential for biological control of Meloidogyne incognita; however, little was known about whether strain 1A00316 could produce volatile organic compounds (VOCs, and if they had potential for use in biological control against M. incognita. In this study, VOCs produced by a culture filtrate of P. putida 1A00316 were evaluated by in vitro experiments in three-compartment Petri dishes and 96-well culture plates. Our results showed that M. incognita juveniles gradually reduced their movement within 24–48 h of incubation with mortality ranging from 6.49 to 86.19%, and mostly stopped action after 72 h. Moreover, egg hatching in culture filtrates of strain 1A00316 was much reduced compared to that in sterile distilled water or culture medium. Volatiles from P. putida 1A00316 analysis carried out by solid-phase micro-extraction gas chromatography–mass spectrometry (SPME-GC/MS included dimethyl-disulfide, 1-undecene, 2-nonanone, 2-octanone, (Z-hexen-1-ol acetate, 2-undecanone, and 1-(ethenyloxy-octadecane. Of these, dimethyl-disulfide, 2-nonanone, 2-octanone, (Z-hexen-1-ol acetate, and 2-undecanone had strong nematicidal activity against M. incognita J2 larvae by direct-contact in 96-well culture plates, and only 2-undecanone acted as a fumigant. In addition, the seven VOCs inhibited egg hatching of M. incognita both by direct-contact and by fumigation. All of the seven VOCs repelled M. incognita J2 juveniles in 2% water agar Petri plates. These results show that VOCs from strain 1A00316 act on different stages in the development of M. incognita via nematicidal, fumigant, and repellent activities and have potential for development as agents with multiple modes of control of root-knot nematodes.

  4. Bioactive Volatiles from an Endophytic Daldinia cf. concentrica Isolate Affect the Viability of the Plant Parasitic Nematode Meloidogyne javanica.

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    Orna Liarzi

    Full Text Available Plant-parasitic nematodes form one of the largest sources of biotic stress imposed on plants, and are very difficult to control; among them are the obligate parasites, the sedentary root-knot nematodes (RKNs-Meloidogyne spp.-which are extremely polyphagous and exploit a very wide range of hosts. Endophytic fungi are organisms that spend most of their life cycle within plant tissue without causing visible damage to the host plant. Many endophytes secrete specialized metabolites and/or emit volatile organic compounds (VOCs that exhibit biological activity. Recently, we demonstrated that the endophytic fungus Daldinia cf. concentrica secrets biologically active VOCs. Here we examined the ability of the fungus and its VOCs to control the RKN M. javanica both in vitro and greenhouse experiments. The D. cf. concentrica VOCs showed bionematicidal activity against the second-stage juveniles (J2s of M. javanica. We found that exposure of J2s to fungal volatiles caused 67% reduction in viability, and that application of a synthetic volatile mixture (SVM, comprising 3-methyl-1-butanol, (±-2-methyl-1-butanol, 4-heptanone, and isoamyl acetate, in volumetric ratio of 1:1:2:1 further reduced J2s viability by 99%. We demonstrated that, although each of the four VOCs significantly reduced the viability of J2s relative to the control, only 4-heptanone elicited the same effect as the whole mixture, with nematicidal activity of 90% reduction in viability of the J2s. Study of the effect of the SVM on egg hatching demonstrated that it decreased eggs hatching by 87%. Finally, application of the SVM to soil inoculated with M. javanica eggs or J2s prior to planting susceptible tomato plants resulted in a significantly reduced galling index and fewer eggs produced on each root system, with no effect on root weight. Thus, D. cf. concentrica and/or SVM based on fungal VOCs may be considered as a novel alternative approach to controlling the RKN M. javanica.

  5. Meloidogyne incognita Fatty Acid- and Retinol- Binding Protein (Mi-FAR-1 Affects Nematode Infection of Plant Roots and the Attachment of Pasteuria penetrans Endospores

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    Victor Phani

    2017-11-01

    Full Text Available Root-knot nematode (RKN Meloidogyne incognita is an economically important pest of crops. Pasteuria penetrans, is a nematode hyperparasitic bacterium capable of suppressing the reproduction of RKN and thereby useful for its management. Secreted fatty acid and retinol-binding proteins are unique in nematodes and are engaged in nutrient acquisition, development and reproduction; they are also a component of the nematode cuticle and thought to be involved in the interface between hosts and parasites. Attachment of endospores to the cuticle of second stage juveniles of RKN is the primary step of infection and several factors have been identified to facilitate attachment. In this study, the full length of Mi-far-1 (573 bp was cloned from M. incognita and characterized. Analysis revealed that the Mi-far-1 was rich in α-helix structure, contained a predicted consensus casein kinase II phosphorylation site and a glycosylation site. Quantitative PCR showed the highest expression in the fourth stage juveniles and in situ hybridization revealed the presence of Mi-far-1 mRNA in the hypodermis below the cuticle. Single copy insertion pattern of Mi-far-1 in M. incognita genome was detected by Southern blotting. Knockdown of Mi-far-1 showed significantly increased attachment of P. penetrans’ endospores on juvenile cuticle surface and also affected host finding, root infection and nematode fecundity.

  6. Coupling of MIC-3 overexpression with the chromosome 11 and 14 root-knot nematode (RKN) (Meloidogyne incognita) resistance QTLs provides insights into the regulation of the RKN resistance response in Upland cotton...

    Science.gov (United States)

    High levels of resistance to root-knot nematode (RKN) (Meloidogyne incognita) in Upland cotton (Gossypium hirsutum) is mediated by two major quantitative trait loci (QTL) located on chromosomes 11 and 14. We had previously determined that MIC-3 expression played a direct role in suppressing RKN egg...

  7. Nematicidal potential of aqueous extract of Hyptis suaveolens in the management of root-knot nematode, Meloidogyne incognita of some cowpea cultivars

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    S. A. Abolusoro

    2016-01-01

    Full Text Available Studies were conducted under field and screenhouse conditions to investigate the potentials of crude aqueous leaf extract of Hyptis suaveolens in the management of the root-knot nematode Meloidogyne incognita of three cowpea varieties (Sampea 9, 10 and 11. A Randomized Complete Block Design was used in the field while a completely randomized design was used for the screenhouse trials. Results showed that the treatment significantly (p < 0.05 improved the growth and yield of the three varieties and also reduced soil nematode population and root galls. It was also observed that all the three varieties were susceptible to the root-knot nematode infestation but Sampea 10 recorded higher yield that were significant in the pot trials. Phytochemical screening revealed the presence of saponins, alkaloids, flavonoids and steroids in the leaves of H. suaveolens. For higher yield of the evaluated cowpea varieties in a nematode endemic zone, aqueous leaf extract of H. suaveolens is being recommended for infested soil treatment.

  8. Characterization of microRNAs from Arabidopsis galls highlights a role for miR159 in the plant response to the root-knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Medina, Clémence; da Rocha, Martine; Magliano, Marc; Ratpopoulo, Alizée; Revel, Benoît; Marteu, Nathalie; Magnone, Virginie; Lebrigand, Kevin; Cabrera, Javier; Barcala, Marta; Silva, Ana Cláudia; Millar, Anthony; Escobar, Carolina; Abad, Pierre; Favery, Bruno; Jaubert-Possamai, Stéphanie

    2017-11-01

    Root knot nematodes (RKN) are root parasites that induce the genetic reprogramming of vascular cells into giant feeding cells and the development of root galls. MicroRNAs (miRNAs) regulate gene expression during development and plant responses to various stresses. Disruption of post-transcriptional gene silencing in Arabidopsis ago1 or ago2 mutants decrease the infection rate of RKN suggesting a role for this mechanism in the plant-nematode interaction. By sequencing small RNAs from uninfected Arabidopsis roots and from galls 7 and 14 d post infection with Meloidogyne incognita, we identified 24 miRNAs differentially expressed in gall as putative regulators of gall development. Moreover, strong activity within galls was detected for five miRNA promoters. Analyses of nematode development in an Arabidopsis miR159abc mutant had a lower susceptibility to RKN, suggesting a role for the miR159 family in the plant response to M. incognita. Localization of mature miR159 within the giant and surrounding cells suggested a role in giant cell and gall. Finally, overexpression of miR159 in galls at 14 d post inoculation was associated with the repression of the miR159 target MYB33 which expression is restricted to the early stages of infection. Overall, these results implicate the miR159 in plant responses to RKN. © 2017 INRA. New Phytologist © 2017 New Phytologist Trust.

  9. Efficacy of Carbofuran in Controlling Root-Knot Nematode (Meloidogyne javanica Whitehead, 1949 on Cultivars of Bambara Groundnut (Vigna subterranea (L. Verdc. in Yola, Nigeria

    Directory of Open Access Journals (Sweden)

    M. Y. Jada

    2011-01-01

    Full Text Available Bambara groundnut (Vigna subterrenea L. Verdc. is an important crop produced in Adamawa State of Nigeria. However, the production of the crop is seriously threatened by root-knot nematodes (RKNs; Meloidogyne spp.. Since cultural methods have not been very effective in controlling RKN, carbofuran was evaluated to determine its efficacy in controlling M. javanica in Yola during 2002 and 2003. Three bambara groundnut cultivars (Kwachanjiwa, Kwaheuma, and Kwatolotolo were evaluated using three application timings (at planting, 3 and 6 weeks after planting, and none. Results indicated that applying carbofuran at planting provided the greatest reduction in M. javanica population levels, which lead to increased yields in bambara groundnuts compared to the other two application timings. Furthermore, both Kwachanjiwa and Kwatolotolo provided similar high yields compared to Kwaheuma, which was most likely related to the M. javanica tolerance in these cultivars.

  10. The map-1 gene family in root-knot nematodes, Meloidogyne spp.: a set of taxonomically restricted genes specific to clonal species.

    Directory of Open Access Journals (Sweden)

    Iva Tomalova

    Full Text Available Taxonomically restricted genes (TRGs, i.e., genes that are restricted to a limited subset of phylogenetically related organisms, may be important in adaptation. In parasitic organisms, TRG-encoded proteins are possible determinants of the specificity of host-parasite interactions. In the root-knot nematode (RKN Meloidogyne incognita, the map-1 gene family encodes expansin-like proteins that are secreted into plant tissues during parasitism, thought to act as effectors to promote successful root infection. MAP-1 proteins exhibit a modular architecture, with variable number and arrangement of 58 and 13-aa domains in their central part. Here, we address the evolutionary origins of this gene family using a combination of bioinformatics and molecular biology approaches. Map-1 genes were solely identified in one single member of the phylum Nematoda, i.e., the genus Meloidogyne, and not detected in any other nematode, thus indicating that the map-1 gene family is indeed a TRG family. A phylogenetic analysis of the distribution of map-1 genes in RKNs further showed that these genes are specifically present in species that reproduce by mitotic parthenogenesis, with the exception of M. floridensis, and could not be detected in RKNs reproducing by either meiotic parthenogenesis or amphimixis. These results highlight the divergence between mitotic and meiotic RKN species as a critical transition in the evolutionary history of these parasites. Analysis of the sequence conservation and organization of repeated domains in map-1 genes suggests that gene duplication(s together with domain loss/duplication have contributed to the evolution of the map-1 family, and that some strong selection mechanism may be acting upon these genes to maintain their functional role(s in the specificity of the plant-RKN interactions.

  11. Salicylic acid-induced glutathione status in tomato crop and resistance to root-knot nematode, Meloidogyne incognita (Kofoid & White Chitwood

    Directory of Open Access Journals (Sweden)

    Hari C. Meher

    2011-10-01

    Full Text Available Salicylic acid-(SA is a plant defense stimulator. Exogenous application of SA might influence the status of glutathione-(GSH. GSH activates and SA alters the expression of defense genes to modulate plant resistance against pathogens. The fate of GSH in a crop following SA treatment is largely unknown. The SA-induced profiles of free reduced-, free oxidized-(GSSG and protein bound-(PSSG glutathione in tomato crop following foliar treatment of transplant at 5.0-10.0 μg mL–1 were measured by liquid chromatography. Resistance to root-knot nematode, Meloidogyne incognita damaging tomato and crop performance were also evaluated. SA treatment at 5.0-10.0 μg mL–1 to tomato transplants increased GSH, GSSG and PSSG in plant leaf and root, more so in leaf, during crop growth and development. As the fruits ripened, GSH and PSSG increased and GSSG declined. SA reduced the root infection by M. incognita, nematode reproduction and thus, improved the resistance of tomato var. Pusa Ruby, but reduced crop growth and redox status. SA at 5.0 μg mL–1 improved yield and fruit quality. The study firstly linked SA with activation of glutathione metabolism and provided an additional dimension to the mechanism of induced resistance against obligate nematode pathogen. SA increased glutathione status in tomato crop, imparted resistance against M. incognita, augmented crop yield and functional food quality. SA can be applied at 5.0 μg mL–1 for metabolic engineering of tomato at transplanting to combine host-plant resistance and health benefits in formulating a strategic nematode management decision.

  12. Wheat bran soil inoculant of sumateran nematode-trapping fungi as biocontrol agents of the root-knot nematode meloidogyne incognita on deli tobacco (nicotiana tabaccum l) cv. deli 4

    Science.gov (United States)

    Dwi Sri Hastuti, Liana; Faull, Jane

    2018-03-01

    A pot experiment was carried out to test the effectiveness of nematode-trapping fungi (NTF) isolated from Sumatera for controlling infection by the root-knot nematode (RKN) on Deli tobacco plant. Wheat bran soil containing 109 conidia of Arthrobotrys. oligospora, Candellabrella musiformis and Dactylella eudermata was added to the soil as a dry inoculum. Carbofuran was also applied as chemical agent and comparison treatment. Seedling tobacco (Nicotiana tabacum L.) cv. Deli 4 was inoculated with root knot (Meloidogyne incognita Chitwood.) seven days after the plant were transplanted to the pots. A. oligospora, C. musiformis and D. eudermata were found to be reliable as biocontrol agents, reducing the number of vermiform nematodes, swollen root, sausage shaped and galls in tobacco plant after 7, 15 and 30 days of infection with M. incognita. Treatment with NTF produced results that were comparable with Carbofuran® as a control agent in the reduction of the number of infections in tobacco plant caused by M. incognita in Nicotiana tabacum var. Deli 4. They also optimize the growth of the tobacco plants especially up to 15 days after infection.

  13. Evaluation of entomopathogenic nematodes and the supernatants of the in vitro culture medium of their mutualistic bacteria for the control of the root-knot nematodes Meloidogyne incognita and M. arenaria.

    Science.gov (United States)

    Kepenekci, Ilker; Hazir, Selcuk; Lewis, Edwin E

    2016-02-01

    The suppressive effects of various formulations of four entomopathogenic nematode (EPN) species and the supernatants of their mutualistic bacteria on the root-knot nematodes (RKNs) Meloidogyne incognita and M. arenaria in tomato roots were evaluated. The EPNs Steinernema carpocapsae, S. feltiae, S. glaseri and Heterorhabditis bacteriophora were applied as either live infective juveniles (IJs) or infected insect cadavers. Spent medium from culturing the bacterial symbionts Xenorhabdus bovienii and Photorhabdus luminescens kayaii with the cells removed was also applied without their nematode partners. The aqueous suspensions of IJs, infected cadaver applications of EPNs and especially treatments of X. bovienii supernatant suppressed the negative impact of RKNs on tomatoes. Specific responses to treatment were reduced RKN egg masses, increased plant height and increased fresh and dry weights compared with the control where only RKNs were applied. Among the treatments tested, the plant-dipping method of X. bovienii into bacterial culture fluid may be the most practical and effective method for M. incognita and M. arenaria control. © 2015 Society of Chemical Industry.

  14. Interactions between an arbuscular mycorrhizal fungus (Scutellospora heterogama and the root-knot nematode (Meloidogyne incognita on sweet passion fruit (Passiflora alata

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    Érika Cristina Teixeira dos Anjos

    2010-08-01

    Full Text Available The effects of inoculation of sweet passion fruit plants with the arbuscular mycorrhizal (AM fungus Scutellospora heterogama on the symptoms produced by Meloidogyne incognita race 1 and its reproduction were evaluated in two greenhouse experiments. In the 1st, the M. incognita (5000 eggs/plant and S. heterogama (200 spores/plant inoculations were simultaneous; in the 2nd, the nematodes were inoculated 120 days after the fungal inoculation. In both the experiments, 220 days after AM fungal inoculation, plant growth was stimulated by the fungus. In disinfested soil, control seedlings (without S. heterogama were intolerant to parasitism of M. incognita, while the growth of mycorrhized seedlings was not affected. Sporulation of S. heterogama was negatively affected by the nematodes that did not impair the colonization. M. incognita did not affect mycorrhizal seedling growth. The establishment of mycorrhiza prior to the nematode infection contributed for the reduction of symptoms severity and reproduction of M. incognita in disinfested soil.O efeito da inoculação com Scutellospora heterogama (200 esporos/planta em relação aos sintomas e reprodução de Meloidogyne incognita raça 1 (5000 ovos/planta foi avaliado em plantas de maracujazeiro doce em dois experimentos em casa de vegetação. No primeiro experimento, inoculações com nematóide e FMA foram simultâneas; no segundo, nematóides foram inoculados 120 dias após o estabelecimento da simbiose micorrízica. Após o 220º dia da inoculação do FMA o fungo estimulou o crescimento da planta nos dois experimentos. No solo desinfestado as mudas não inoculadas com S. heterogama mostraram intolerância ao parasitismo de M. incognita. A esporulação de S. heterogama foi negativamente afetada pela presença do nematóide. M. incognita não afetou o crescimento das mudas micorrizadas ou o desenvolvimento do FMA. O estabelecimento da micorriza antes do nematóide contribui para a redução da

  15. Behaviour of Heterodera glycines and Meloidogyne incognita infective juveniles exposed to nematode FMRFamide-like peptides in vitro

    Science.gov (United States)

    Plant-parasitic nematodes depend upon a family of neuropeptides, the FMRFamide-like peptides (FLPs), to regulate locomotion and behavior. To exploit FLPs as leads to novel nematode control agents, an understanding of how specific FLPs affect behavior, and what differences exist between species, is i...

  16. Management of Meloidogyne incognita in nematodesusceptible ...

    African Journals Online (AJOL)

    Watermelon (Citrullus lanatus) cultivars are highly susceptible to the southern root-knot nematode (Meloidogyne incognita), with considerable yield losses when this nematode is not managed. Empirical evidence suggested that wild watermelon (Cucumis africanus) and wild cucumber (Cucumis myriocarpus) were highly ...

  17. Antinematicidal Efficacy Of Root Exudates Of Some Crotalaria Species On Meloidogyne Incognita Root-Knot Nematode Kofoid And White Chitwood Isolated From Infected Lycopersicum Esculentum L.Tomato Plant

    Directory of Open Access Journals (Sweden)

    L.S Danahap

    2015-08-01

    Full Text Available The antinematicidal efficacies of exudates of four common weeds Crotalaria breviflora Crotalaria juncea Crotalaria retusa and Crotalaria spectabilis were carried out against Meloidogyne incognita. The young actively growing seedling of the common weeds were uprooted and taken to the laboratory for analyses. The root exudates of test plants were prepared by growing the young actively growing seedlings in test tubes wrapped with black carbon paper for five days under lighted florescent bulbs. Root exudates of Crotalaria breviflora Crotalaria juncea Crotalaria retusa and Crotalaria spectabilis exhibited nematicidal properties against the Meloidogyne incognita. The effects varied with concentrations of the exudates P0.05 using analysis of variance ANOVA. The effects also differed among test plants with Crotalaria retusa topping in terms of reduction in nematode population. This was followed by C.breviflora C.juncea and C.spectabilis respectively. The results thus confirmed that all the test plants are potentially viable trap weeds and can be used for the control of Meloidogyne incognita and should be employed as such.

  18. Overexpression of the Prunus sogdiana NBS-LRR Subgroup Gene PsoRPM2 Promotes Resistance to the Root-Knot Nematode Meloidogyne incognita in Tobacco

    Science.gov (United States)

    Zhu, Xiang; Xiao, Kun; Cui, Haiyang; Hu, Jianfang

    2017-01-01

    Root-knot nematodes (RKNs), particularly Meloidogyne incognita, are the most devastating soil-borne pathogens that significantly affect the production of Prunus spp. fruit. RKN infection is difficult to control and consequently causes massive yield losses each year. However, several germplasms of wild Prunus spp. have been shown to display resistance to M. incognita. Consequently, both the isolation of novel plant resistance (R) genes and the characterization of their resistance mechanisms are important strategies for future disease control. R proteins require the co-chaperone protein HSP90-SGT1-RAR1 to achieve correct folding, maturation, and stabilization. Here, we used homologous cloning to isolate the R gene PsoRPM2 from the RKN-resistant species Prunus sogdiana. PsoRPM2 was found to encode a TIR-NB-LRR-type protein and react with significantly elevated PsoRPM2 expression levels in response to RKN infection. Transient expression assays indicated PsoRPM2 to be located in both the cytoplasm and the nucleus. Four transgenic tobacco lines that heterologously expressed PsoRPM2 showed enhanced resistance to M. incognita. Yeast two-hybrid analysis and bimolecular fluorescence complementation analysis demonstrated that both PsoRAR1 and PsoRPM2 interacted with PsoHSP90-1 and PsoSGT1, but not with one another. These results indicate that the observed PsoRPM2-mediated RKN resistance requires both PsoHSP90-1 and PsoSGT1, further suggesting that PsoRAR1 plays a functionally redundant role in the HSP90-SGT1-RAR1 co-chaperone. PMID:29163405

  19. Overexpression of the Prunus sogdiana NBS-LRR Subgroup Gene PsoRPM2 Promotes Resistance to the Root-Knot Nematode Meloidogyne incognita in Tobacco

    Directory of Open Access Journals (Sweden)

    Xiang Zhu

    2017-10-01

    Full Text Available Root-knot nematodes (RKNs, particularly Meloidogyne incognita, are the most devastating soil-borne pathogens that significantly affect the production of Prunus spp. fruit. RKN infection is difficult to control and consequently causes massive yield losses each year. However, several germplasms of wild Prunus spp. have been shown to display resistance to M. incognita. Consequently, both the isolation of novel plant resistance (R genes and the characterization of their resistance mechanisms are important strategies for future disease control. R proteins require the co-chaperone protein HSP90-SGT1-RAR1 to achieve correct folding, maturation, and stabilization. Here, we used homologous cloning to isolate the R gene PsoRPM2 from the RKN-resistant species Prunus sogdiana. PsoRPM2 was found to encode a TIR-NB-LRR-type protein and react with significantly elevated PsoRPM2 expression levels in response to RKN infection. Transient expression assays indicated PsoRPM2 to be located in both the cytoplasm and the nucleus. Four transgenic tobacco lines that heterologously expressed PsoRPM2 showed enhanced resistance to M. incognita. Yeast two-hybrid analysis and bimolecular fluorescence complementation analysis demonstrated that both PsoRAR1 and PsoRPM2 interacted with PsoHSP90-1 and PsoSGT1, but not with one another. These results indicate that the observed PsoRPM2-mediated RKN resistance requires both PsoHSP90-1 and PsoSGT1, further suggesting that PsoRAR1 plays a functionally redundant role in the HSP90-SGT1-RAR1 co-chaperone.

  20. Process development of oxalic acid production in submerged culture of Aspergillus niger F22 and its biocontrol efficacy against the root-knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Lee, Sang Il; Lee, Keon Jin; Chun, Ho Hyun; Ha, Sanghyun; Gwak, Hyun Jung; Kim, Ho Myeong; Lee, Jong-Hee; Choi, Hak-Jong; Kim, Hyeong Hwan; Shin, Teak Soo; Park, Hae Woong; Kim, Jin-Cheol

    2018-03-01

    Oxalic acid has potent nematicidal activity against the root-knot nematode Meloidogyne incognita. In this study, fermentation parameters for oxalic acid production in submerged culture of Aspergillus niger F22 at 23, 25, and 30 °C were optimized in 5-L jar fermenters. The viscosity of the culture broth increased with increasing temperature. There was a negative correlation between oxalic acid production and the apparent viscosity; high volumetric productivity of oxalic acid was obtained at low apparent viscosity (less than 1000 cP), with a productivity of more than 100 mg/L h. When the apparent viscosity was over 2500 cP, the volumetric productivity decreased below 50 mg/L h. In addition, the volumetric mass transfer coefficient, K L a, positively correlated with volumetric productivity. When the K L a value increased from 0.0 to 0.017 /s, the volumetric productivity proportionally increased up to 176 mg/L h. When the temperature decreased, K L a increased due to the decrease in viscosity, leading to increased volumetric productivity. The highest productivity of 7453.3 mg/L was obtained at the lowest temperature, i.e., 23 °C. The nematicidal activity of culture filtrate was proportional to the content of oxalic acid. Based on a constant impeller tip speed, oxalic acid production was successfully scaled up to a 500-L pilot vessel, producing a final concentration comparable to that in the 5-L jar.

  1. Host genetic resistance to root-knot nematodes, Meloidogyne spp., in Solanaceae: from genes to the field.

    Science.gov (United States)

    Barbary, Arnaud; Djian-Caporalino, Caroline; Palloix, Alain; Castagnone-Sereno, Philippe

    2015-12-01

    Root-knot nematodes (RKNs) heavily damage most solanaceous crops worldwide. Fortunately, major resistance genes are available in a number of plant species, and their use provides a safe and economically relevant strategy for RKN control. From a structural point of view, these genes often harbour NBS-LRR motifs (i.e. a nucleotide binding site and a leucine rich repeat region near the carboxy terminus) and are organised in syntenic clusters in solanaceous genomes. Their introgression from wild to cultivated plants remains a challenge for breeders, although facilitated by marker-assisted selection. As shown with other pathosystems, the genetic background into which the resistance genes are introgressed is of prime importance to both the expression of the resistance and its durability, as exemplified by the recent discovery of quantitative trait loci conferring quantitative resistance to RKNs in pepper. The deployment of resistance genes at a large scale may result in the emergence and spread of virulent nematode populations able to overcome them, as already reported in tomato and pepper. Therefore, careful management of the resistance genes available in solanaceous crops is crucial to avoid significant reduction in the duration of RKN genetic control in the field. From that perspective, only rational management combining breeding and cultivation practices will allow the design and implementation of innovative, sustainable crop production systems that protect the resistance genes and maintain their durability. © 2015 Society of Chemical Industry.

  2. Occurrence of Meloidogyne spp. in Argentina.

    Science.gov (United States)

    Doucet, M E; Pinochet, J

    1992-12-01

    A record of 84 plant species in 32 families that are hosts to the root-knot nematode species found in Argentina is presented. The genus Meloidogyne appears to be widely distributed in the country, with Meloidogyne incognita and M. javanica the most frequently detected species. Other species found in Argentina include M. arenaria, M. cruciani, M. decalineata, M. hapla, and M. ottersoni. The present survey is supplemented with existing published information.

  3. Coupling of MIC-3 overexpression with the chromosomes 11 and 14 root-knot nematode (RKN) (Meloidogyne incognita) resistance QTLs provides insights into the regulation of the RKN resistance response in Upland cotton (Gossypium hirsutum).

    Science.gov (United States)

    Wubben, Martin J; Callahan, Franklin E; Jenkins, Johnie N; Deng, Dewayne D

    2016-09-01

    Genetic analysis of MIC-3 transgene with RKN resistance QTLs provides insight into the resistance regulatory mechanism and provides a framework for testing additional hypotheses. Resistance to root-knot nematode (RKN) (Meloidogyne incognita) in Upland cotton (Gossypium hirsutum) is mediated by two major quantitative trait loci (QTL) located on chromosomes 11 and 14. The MIC-3 (Meloidogyne Induced Cotton3) protein accumulates specifically within the immature galls of RKN-resistant plants that possess these QTLs. Recently, we showed that MIC-3 overexpression in an RKN-susceptible cotton genotype suppressed RKN egg production but not RKN-induced root galling. In this study, the MIC-3 overexpression construct T-DNA in the single-copy transgenic line '14-7-1' was converted into a codominant molecular marker that allowed the marker assisted selection of F2:3 cotton lines, derived from a cross between 14-7-1 and M-240 RNR, having all possible combinations of the chromosomes 11 and 14 QTLs with and without the MIC-3 overexpression construct. Root-knot nematode reproduction (eggs g(-1) root) and severity of RKN-induced root galling were assessed in these lines. We discovered that the addition of MIC-3 overexpression suppressed RKN reproduction in lines lacking both resistance QTLs and in lines having only the chromosome 14 QTL, suggesting an additive effect of the MIC-3 construct with this QTL. In contrast, MIC-3 overexpression did not improve resistance in lines having the single chromosome 11 QTL or in lines having both resistance QTLs, suggesting an epistatic interaction between the chromosome 11 QTL and the MIC-3 construct. Overexpression of MIC-3 did not affect the severity of RKN-induced root galling regardless of QTL genotype. These data provide new insights into the relative order of action of the chromosomes 11 and 14 QTLs and their potential roles in regulating MIC-3 expression as part of the RKN resistance response.

  4. The significance of ecology in the development of Verticillium chlamydosporium as a biological control agent against root-knot nematodes (Meloidogyne spp.)

    OpenAIRE

    Leij, de, F.A.A.M.

    1992-01-01

    A thorough understanding of the interactions which occur between nematode parasites and nematode pests and the influence of biotic and abiotic factors on these interactions, is essential in the development of biological control agents for nematodes. The aim of this study was to develop a particular isolate of the nematophagous fungus Verticillium chlamydosporium as a biological control agent for root-knot nematodes. The work has gained insight into some of the ke...

  5. The significance of ecology in the development of Verticillium chlamydosporium as a biological control agent against root-knot nematodes (Meloidogyne spp.)

    NARCIS (Netherlands)

    Leij, de F.A.A.M.

    1992-01-01

    A thorough understanding of the interactions which occur between nematode parasites and nematode pests and the influence of biotic and abiotic factors on these interactions, is essential in the development of biological control agents for nematodes. The aim of this study was to develop a

  6. Resistance of maize to Meloidogyne arenaria and Meloidogyne javanica.

    Science.gov (United States)

    Williams, W P; Windham, G L

    1990-12-01

    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 combining ability was not a significant source of variation for either. The correlation between egg production of the two nematode species on the 28 F1 hybrids was highly significant. Hybrids with Mp313 or SC213 as one parent were the most resistant to both species. This indicates that germ plasm is available for developing inbred lines and hybrids with resistance to both M. arenaria race 2 and M. javanica.

  7. Metagenomic insights into communities, functions of endophytes, and their associates with infection by root-knot nematode, Meloidogyne incognita, in tomato roots.

    Science.gov (United States)

    Tian, Bao-Yu; Cao, Yi; Zhang, Ke-Qin

    2015-11-25

    Endophytes are known to play important roles in plant's health and productivity. In this study, we investigated the root microbiome of tomato in association with infection by root knot nematodes. Our objectives were to observe the effects and response of the bacterial endophytes before nematode attacks and to reveal the functional attributes of microbes in plant health and nematode pathogenesis. Community analysis of root-associated microbiomes in healthy and nematode-infected tomatoes indicated that nematode infections were associated with variation and differentiation of the endophyte and rhizosphere bacterial populations in plant roots. The community of the resident endophytes in tomato root was significantly affected by nemato-pathogenesis. Remarkably, some bacterial groups in the nematode feeding structure, the root gall, were specifically enriched, suggesting an association with nematode pathogenesis. Function-based metagenomic analysis indicated that the enriched bacterial populations in root gall harbored abundant genes related to degradation of plant polysaccharides, carbohydrate and protein metabolism, and biological nitrogen fixation. Our data indicated that some of the previously assumed beneficial endophytes or bacterial associates with nematode might be involved in nematode infections of the tomato roots.

  8. Shifting from priming of salicylic acid- to jasmonic acid-regulated defences by Trichoderma protects tomato against the root knot nematode Meloidogyne incognita

    NARCIS (Netherlands)

    Martínez-Medina, Ainhoa; Fernandez, Ivan; Lok, Gerrit B; Pozo, María J; Pieterse, Corné M J; Van Wees, Saskia C M

    Beneficial root endophytes such as Trichoderma spp. can reduce infections by parasitic nematodes through triggering host defences. Little is currently known about the complex hormone signalling underlying the induction of resistance. In this study, we investigated whether Trichoderma modulates the

  9. IDENTIFICACIÓN DE GENES CANDIDATOS DE PATOGENICIDAD EN LA INTERACCIÓN DE LA CEPA CENICAFE 9501 CON EL NEMÁTODO DEL NUDO RADICAL Meloidogyne spp. IDENTIFICATION OF PATHOGENIC CANDIDATES GENES IN THE INTERACTION OF THE CENICAFE 9501 STRAIN WITH THE ROOT KNOT NEMATODE Meloidogyne spp.

    Directory of Open Access Journals (Sweden)

    Nadya Lorena Cardona Bustos

    2008-12-01

    Full Text Available En 1997 se registró por primera vez el aislamiento de un hongo Hyphomycete de suelos de Chinchiná (Caldas, Colombia atacando huevos y otros estadios biológicos de las especies de nematodos fitoparásitos Meloidogyne incognita y M. javanica provenientes de lotes comerciales con café. Debido a la imposibilidad de clasificarlo taxonómicamente en los géneros actuales, este aislamiento se ha denominado temporalmente como CENICAFE 9501. Dado su potencial como biocontrolador, se propuso identificar genes candidatos involucrados en el proceso de patogenicidad de huevos de Meloidogyne. Con este fin se construyeron librerías diferenciales mediante el método de hibridación sustractiva. La secuenciación de 188 clones obtenidos permitió identificar 80 unigenes, de los cuales el mayor porcentaje correspondió a secuencias sin homología (32%, seguidas por genes candidatos a funciones de patogénesis (22%, transporte celular (17%, síntesis de proteínas (11% y en menor proporción aquellos involucrados con transcripción y metabolismo primario (18%. Dentro de aquellos genes que contienen marcos de lectura con homología a proteínas que intervienen en la patogenicidad se encuentran una peptidasa, un receptor para sitios de ubiquitinación, una deubiquinasa, una ubiquinona oxidoreductasa, proteína relacionada con la degradación de pared celular, glicosil hidrolasa e hidroxilasa de ácidos grasos, asi como una serin proteasa. Se hace necesaria la validación de las funciones putativas de estos genes candidatos con el fin de incrementar el conocimiento básico de la fisiología de este hongo con potencial biorregulador.In 1997 it was reported for the first time from soil isolation of a Hyphomycete fungus from Chinchiná ( Caldas, Colombia , attacking eggs and other biological stages of the plant parasite nematodes Meloidogyne incognita and M. javanica, from commercial coffee plots. Due to the impossibility to classify it taxonomically under current

  10. Genetic analysis of root-knot nematode resistance in potato

    NARCIS (Netherlands)

    Draaistra, J.

    2006-01-01

    The development of potato varieties with resistance towards the potato cyst nematode, allowed a dramatic decrease of the use of nematicides. Subsequently the population of the free living nematodes and the root-knot nematodes ( Meloidogyne spp.) has increased. Among the root-knot nematodes, three

  11. Nematicide and nematostatic potential of Curcuma longa on Meloidogyne incognita

    Directory of Open Access Journals (Sweden)

    Thaísa Muriel Mioranza

    2016-08-01

    Full Text Available The root knot nematodes can reduce yield potential of plants, thus requiring searching control methods that are effective and eco-friendly. The purpose of this study was to analyze the efficiency of turmeric rhizome aqueous extract (Curcuma longa on hatching, immobilization and mortality of juveniles of Meloidogyne incognita. A completely randomized design was used, with concentrations of 1%, 5%, 10% and 15% of turmeric extract and distilled water as a control treatment, with four replications. The juveniles of nematodes were directly exposed to turmeric extract for 24 h, while eggs were exposed during 15 days. The turmeric extract on J2 of Meloidogyne incognita, in vitro tests, promoted from the concentration of 10% total paralysis of nematodes and in the concentration of 15% more than 90% mortality. All tested concentrations caused reduction in juveniles hatching. Thereby, the turmeric aqueous extract has nematicidal potential against M. incognita, encouraging its study in the interaction plant-nematode.

  12. Response of meloidogyne hapla to mycorrhiza fungi inoculation on ...

    African Journals Online (AJOL)

    Five arbuscular mycorrhiza fungi (AMF) isolated from pyrethrum were screened in the greenhouse for efficacy in improving pyrethrum growth and in suppressing a root-knot nematode, Meloidogyne hapla. The fungi screened were Glomus spp. (isolates LM61, ML34 and ML35), Scutellospora sp. (isolate KS74) and ...

  13. Evaluation of roselle (Hibiscus sabdariffa) leaf and pomegranate (Punica granatum) fruit rind for activity against Meloidogyne incognita

    Science.gov (United States)

    Pomegranate (Punica granatum) fruit and roselle (Hibiscus sabdariffa) leaves have been used in traditional medicine, including as anthelmintics. Methanolic extracts from these plants were investigated for activity against the southern root-knot nematode (RKN) Meloidogyne incognita. Dried, ground p...

  14. Physiological and DNA fingerprinting of the bacterial community of Meloidogyne fallax egg masses

    NARCIS (Netherlands)

    Papert, A; Kok, CJ; van Elsas, JD

    2004-01-01

    Bacterial communities associated with the plant-parasitic nematode Meloidogyne fallax egg masses were compared with those present in the rhizoplane. Two agricultural soils with different nematode population dynamics were used in a glasshouse study, with either potato or tomato as host plant for the

  15. Morphological, biochemical, and molecular characterization of Meloidogyne spp. populations from Brazilian soybean production regions

    Directory of Open Access Journals (Sweden)

    Camilla Martins de Oliveira

    Full Text Available ABSTRACT: Soybean is a commodity of great economic importance worldwide, particularly in Brazil, world’s second largest producer. Nematodes, especially those of the Meloidogyne genus, severely limit productivity. Identification of nematode species is important for effective soybean management. Here, 26 populations of root-knot nematode (Meloidogyne spp. from 15 municipalities in the states of Bahia, Mato Grosso, Goias, and Minas Gerais were characterized based on the morphology of the female perineal region, esterase profile, and identification based on amplification of specific regions of the population genome. Among the Meloidogyne spp. populations obtained, M. incognita and M. javanica, were identified. No mixed populations were present in the samples. Diagnosis based on molecular analysis was shown to be reliable and the fastest for characterization of nematode populations compared to other methods analyzed.

  16. Survey of Nematodes on Coffee in Hawaii

    Science.gov (United States)

    Schenck, S.; Schmitt, D. P.

    1992-01-01

    Surveys of coffee fields in Hawaii during 1989-1991 indicated the presence of 10 nematode species in 8 genera. After coffee was planted in fields previously in sugarcane, populations of Criconemella sp. and Pratylenchus zeae gradually decreased, while Rotylenchulus reniformis and, in one field, Meloidogyne incognita, increased in numbers. Coffee is a poor host of R. reniformis, but weeds in coffee plantations may support this nematode. At present, nematodes pose no serious threat to Hawaii's expanding coffee industry. PMID:19283060

  17. Survey of Nematodes on Coffee in Hawaii

    OpenAIRE

    Schenck, S.; Schmitt, D. P.

    1992-01-01

    Surveys of coffee fields in Hawaii during 1989-1991 indicated the presence of 10 nematode species in 8 genera. After coffee was planted in fields previously in sugarcane, populations of Criconemella sp. and Pratylenchus zeae gradually decreased, while Rotylenchulus reniformis and, in one field, Meloidogyne incognita, increased in numbers. Coffee is a poor host of R. reniformis, but weeds in coffee plantations may support this nematode. At present, nematodes pose no serious threat to Hawaii's ...

  18. Interaction of Fusarium oxysporum with Meloidogyne incognita on Roselle

    Directory of Open Access Journals (Sweden)

    K. H. Ooi

    1999-12-01

    Full Text Available Forty isolates of Fusarium oxysporum were tested for their pathogenicity to roselle (Hibiscus sabdariffa L. var. sabdariffa in a plant house. The most virulent isolate was later used in a disease complex experiment with a root-knot nematode Meloidogyne incognita. Disease severity of roselle seedlings inoculated with a combination of fungus and nematode was higher than those inoculated with either fungus or nematode individually. Seedlings that were inoculated with fungus two weeks after nematode inoculation showed the highest disease severity compared to that inoculated with nematode two weeks after fungal inoculation or that inoculated simultaneously with both pathogens. It seems that root infections by M. incognita increased the colonization of roselle by F. oxysporum and subsequently caused higher damage to the roselle seedlings. The high wilt incidence in the presence of M. incognita and F. oxysporum may be due to the synergistic relationship between these two pathogens.

  19. Rapid identification of cyst (Heterodera spp., Globodera spp.) and root-knot (Meloidogyne spp.) nematodes on the basis of ITS2 sequence variation detected by PCR-single-strand conformational polymorphism (PCR-SSCP) in cultures and field samples

    NARCIS (Netherlands)

    Clapp, J.P.; Van der Stoel, C.D.; Van der Putten, W.H.

    2000-01-01

    Cyst and root-knot nematodes show high levels of gross morphological similarity. This presents difficulties for the study of their ecology in natural ecosystems. In this study, cyst and root-knot nematode species, as well as some ectoparasitic nematode species, were identified using the second

  20. Grafting guava on cattley guava resistant to Meloidogyne enterolobii

    OpenAIRE

    Robaina,Renata Rodrigues; Campos,Graziella Siqueira; Marinho,Cláudia Sales; Souza,Ricardo Moreira; Bremenkamp,Cíntia Aparecida

    2015-01-01

    The use of resistant rootstocks could be a promising method to control nematodeMeloidogyne enterolobiiin commercial plantations of guava. The present study aimed to evaluate the success of grafting guava as a scion on accessions of cattley guava as rootstocks resistant to M. enterolobii.The treatments consisted of the rootstocks cattley guava plants (three accessions of Psidium cattleyanum) and common guava (control). In the apical wedge grafting method, scion of Paluma cultivated variety was...

  1. Pengendalian Nematoda Puru Akar (Meloidogyne spp. pada Buncis dengan Bakteri Pasteuria penetrans dan Solarisasi

    Directory of Open Access Journals (Sweden)

    B. Triman

    2001-07-01

    Full Text Available The objectives of the research were to study the effect of P. penetrans and soil solarization on the population of root-knot nematodes (Meloidogyne spp. and the effect of soil solarization on the infectivity of P. penetrans. The research was done in the field with high population of plant parasitic nematode especially root-knot nematodes. Soil solarization was done in dry season by covering the soil before french beans (buncis were planted with transparent plastic and P. penetrans were inoculated before soil solarization. Factorial design in Completely Randomized Design was used in this experiment with the following factors: 1 soil solarization (within 1, 2, and 3 moths; 2 isolates of P. penetrans (i.e. isolate 2 and 3. The research results were: 1 Isolate 2 and 3 of P. penetrans were able to parasitize root-knot nematodes in soil solarized within 1, 2, and 3 months; 2 the length of soil solarization afected the infectivity of P. penetrans on Meloidogyne spp. The percentages of Meloidogyne spp. infected with isolate 2 of P. penetrans in soil solarization within 1, 2, and 3 months were 40.3%; 25.7%, and 10.1%, respectively, whereas in soil inoculated with isolate 3 of P. penetrans were: 37.3%, 10.2%, and 2.2%, respectively; 3 inoculation of P. penetrans reduced the root damage caused by root-knot nematodes (Meloidogyne spp.; and 4 treatment of P. penetrans combined with soil solarization reduced the root damage caused by root-knot nematodes (Meloidogyne spp.. Key words: Pasteuria penetrans, soil solarization, root-knot nematode

  2. Evaluation of potential bio-control agents on root-knot nematode ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-05-11

    May 11, 2016 ... nematode, Meloidogyne incognita and Fusarium oxysporum f.sp. conglutinans in vitro. Cell free ... are manifested by the formation of root galls accompanied by stunted growth, chlorosis and loss of viability of the plant (Babu et al., 1999). Fusarium wilt is ... effective bio-control agent on Meloidogyne spp. on.

  3. Towards isolation of the tomato root-knot nematode resistance gene MI via positional cloning

    NARCIS (Netherlands)

    Daelen, van R.A.J.J.

    1995-01-01

    Root-knot nematodes of the genus Meloidogyne are severe pathogens of plants and worldwide they cause damage to many economically important crops like potato, rice, cotton, and tomato. So the control of nematodes and the protection of plants against nematode damage are

  4. Developmental and behavioural effects of the endophytic Fusarium moniliforme Fe14 towards Meloidogyne graminicola in rice

    NARCIS (Netherlands)

    Le, H.T.T.; Padgham, J.L.; Hagemann, M.H.; Sikora, R.A.; Schouten, Sander

    2016-01-01

    The root-knot nematode, Meloidogyne graminicola, is an important pest of rice in many rice production areas worldwide. The endophyte Fusarium moniliforme strain Fe14, isolated from a disinfected root of rice, has previously shown potential antagonistic activity against M. graminicola. This study

  5. Effect of local tree seeds in the control of root knot nematode Meloidogyne javanica (Treub chitwood and growth promotion of chickpea (Cicer arietinum L. and mung bean (Vigna radiata L.

    Directory of Open Access Journals (Sweden)

    Zainab M. Ahmed

    2012-12-01

    Full Text Available Seeds of local trees, such Azadirachta indica A. Juss, Adenanthera pavonina L., Leucaena leucocephala (Lam. de Wit and Eucalyptus spp., were used as aqueous extract at 25, 50 and 100 % concentration to control the activity of Meloidogyne javanica (Treub Citwood. All seed extracts showed lethal effect on M. javanica eggs, and a gradual decrease in egg hatching and an increase in mortality of second-stage juveniles were observed with the increase in extract concentration. L. leucocephala was found to be most effective in reducing egg hatching, whereas 100 % mortality of juveniles was observed in the case of A. indica seed extract. Number of knots was significantly reduced at 100 % concentration when seeds of chick pea and mung bean were treated and soil was drenched with A. pavonina and Eucalyptus spp. seed extract.

  6. Relationship between production, nematodes and "redness" in strawberries

    Directory of Open Access Journals (Sweden)

    Paula Nogueira Curi

    2016-08-01

    Full Text Available ABSTRACT: In recent years "redness" has increasingly appeared in strawberry plants with leaves taking on a reddish color. No causal agent has been associated with plants. Since strawberries presented problems due to the incidence of nematodes, the purpose of this study was to look at the relationship between production, resistance to the Meloidogyne hapla nematode and the "redness" symptom in strawberry cultivars. Two experiments were performed, both with the 'Camino Real', 'Festival', 'Oso Grande', 'Albion' and 'Camarosa' cultivars. The first experiment was performed in the field, where the following were evaluated: strawberry production, fruit quality, macro and micronutrient contents in fruit and leaves, percentage of plant survival, incidence of nematodes, quantity of eggs in the roots and juveniles in the soil, and the incidence of Botrytis cinerea . In the second experiment, the strawberries were transplanted into pots and filled with pinus bark-based commercial substrate. Half the pots were inocculated with Meloidogyne hapla . Cultivars presented differences in fruit production and also in the incidence of "redness". Lowest performance in production was related to the high incidence of the nematode Meloidogyne hapla. 'Oso Grande' and 'Albion' presented nematode-resistant behavior. It was possible find a relationship between the incidence of the Meloidogyne hapla nematode, and the incidence of "redness" only 'Camino Real' cultivar.

  7. Physiological changes in leaves of mungbean plants infected with Meloidogyne javanica

    Directory of Open Access Journals (Sweden)

    N. Ahmed

    2009-09-01

    Full Text Available Sequential changes induced by the root-knot nematode Meloidogyne javanica (Treub Chitwood in mung bean (Vigna radiata (L. Wilczek cv. MN95 were studied. Physiological and biochemical changes were recorded 15, 30 and 45 days after nematode inoculation. The changes noted varied with the length of exposure to the nematode. Chlorophyll and carotenoid contents decreased in nematode-infected plants. Total phenols increased in the leaves compared with the controls for up to 30 days after inoculation. Protein content declined significantly at 30 days after exposure to the nematodes. Amylase activity was enhanced in both the leaves and the stems as compared with the controls. The results suggested that plants responded to the nematode by adopting biochemical strategies to withstand the adverse effects of infection.

  8. Molecular Cloning and Characterization of a Wild Eggplant Solanum aculeatissimum NBS-LRR Gene, Involved in Plant Resistance to Meloidogyne incognita

    OpenAIRE

    Xiaohui Zhou; Jun Liu; Shengyou Bao; Yan Yang; Yong Zhuang

    2018-01-01

    Root-knot nematodes, Meloidogyne spp., cause considerable damage in eggplant production. Transferring of resistance genes from wild relatives would be valuable for the continued improvement of eggplant. Solanum aculeatissimum, a wild relative of eggplant possessing resistance to Meloidogyne incognita, is potentially useful for genetically enhancing eggplant. In the present study, we have isolated and characterized a nucleotide-binding site leucine-rich repeat (NBS-LRR) resistance gene, design...

  9. RESISTANCE OF POTATO GENOTYPES TO Meloidogyne javanica

    Directory of Open Access Journals (Sweden)

    JAQUELINE TAVARES SCHAFER

    2017-01-01

    Full Text Available The objective of this study was to evaluate the resistance of a group of clones and cultivars from the potato breeding program of Embrapa to Meloidogyne javanica . The experiment was conducted at Embrapa Temperate Climate, Pelotas / RS, under greenhouse conditions at temperatures of 25 ± 5°C. Individual potato plants of different genotypes [BRSIPR Bel, BRS F63 (Camila, CL02 - 05, F23 - 11 - 06, F32 - 02 - 06, F38 - 03 - 07, F189 - 09 - 06, F23 - 24 - 06 and F22 - 01 - 08], kept in pots with sterilized soil were inoculated with 5,000 eggs and J2 of M. javanica , using six replicates per treatment. The susceptible control, potato cultivar BRS Ana was inoculated with the same level of inoculum. Fifty - five days after inoculation, the number of galls on the roots of each plant was determined as well as the number of protuberances caused by nematodes in the different treatments. Then, the roots of each plant were processed for counting the number of eggs and J2, as well as determining the nematode reproduction factor (FR: final population / initial population. All genotypes were susceptible (FR> 1.00 to M. javanica . However, there were different levels of susceptibility among the cultivars tested.

  10. Native-plant hosts of Meloidogyne spp. from Western Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Vanessa A. Antes

    2012-04-01

    Full Text Available The present study was focused on the parasitism of Meloidogyne species on the roots of native nursery plants from the Atlantic forest. Native plants were selected from a commercial nursery in Western Paraná, searching for the natural infection of Meloidogyne. Also, the seeds of native plants were cultivated in sterile soil and inoculated with M. incognita. In both the experiments, the number of galls and number of eggs and J2 per root, allied to the reproduction factor of M. incognita on each inoculated plant were assessed. Natural infection by M. javanica was found on Cordia ecalyculata, Citharexyllum myrianthum and Aspidosperma subincanum and by M. incognita on Croton urucurana, Lonchocarpus muehlbergianus, Tabebuia impetiginosa and T. serratifolia. Meloidogyne incognita induced galls formation on Genipa americana, Schinus terebinthifolius and Rollinia mucosa after inoculation, which suggested that those plants could host this nematode in natural biomes. Nursery soil should be disinfested before seeding the native forest plants for reforestation purposes

  11. Evaluation of tomato genotypes for resistance to root-knot nematodes

    African Journals Online (AJOL)

    Tomato (Solanum lycopersicum) is one of the most popular vegetable crops worldwide, owing to its high nutritive value and diversified use. Tomato production in Ghana is threatened by plant parasitic nematodes, especially the root knot nematodes (Meloidogyne spp.), which are responsible for huge economic yield losses.

  12. Geschikte onderstammen voor biologisch geteelde komkommers, tomaten en paprika's in relatie tot wortelknobbelaaltjes (Meloidogyne spp.) - Resultaten onderzoek 2006-2010

    NARCIS (Netherlands)

    Janse, J.; Slooten, van M.A.; Wurff, van der A.W.G.

    2011-01-01

    During 5 years, Wageningen UR Greenhouse Horticulture did research to find a rootstock with high resistance against the most important root knot nematodes or Meloidogyne species in greenhouses in the Netherlands, M. incognita, M. hapla and M. javanica. Rootstocks should combine resistance with good

  13. Microflora of Meloidogyne egg masses: species composition, population density and effect on the biocontrol agent Verticillium chlamudosporium (Goddard)

    NARCIS (Netherlands)

    Kok, C.J.; Papert, A.; Hok-A-Hin, C.H.

    2001-01-01

    Egg masses of Meloidogyne fallax from tomato and potato growing in soil from a nematode suppressive and a nonsuppressive field sustained bacterial population densities two to three orders of magnitude higher than those of the rhizosphere soil. BIOLOG metabolic profiling identified 16 bacterial

  14. Reaction of Prunus Rootstocks to Meloidogyne incognita and M. arenaria in Spain.

    Science.gov (United States)

    Marull, J; Pinochet, J; Verdejo-Lucas, S; Soler, A

    1991-10-01

    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 nine other rootstocks expressed various degrees of susceptibility. All Spanish rootstocks were susceptible to both Meloidogyne species except for the three G x N selections. The root-knot nematode resistant peach Nemared used as a male parent with Garfi was found to transmit a high degree of resistance to M. incognita and immunity to M. arenaria. Progenies of P. davidiana (Ga x D no. 3), a known source of resistance to root-knot nematodes, were susceptible.

  15. GESTION DES NEMATODES A GALLES PARASITES DE LA ...

    African Journals Online (AJOL)

    ACSS

    Galeano, M. 2003. Evaluating Pochonia chlamydosporia in a double-cropping system of lettuce and tomato in plastic houses infested with Meloidogyne javanica. Plant Pathology 52: 521-528. Westerdahl, B.B. et Becker, J.O. 2009. Cucurbit Nematodes. UC Pest Management. Guidelines: Cucurbits. UC ANR Publication.

  16. Maintenance of genetic variation in automictic root-knot nematodes

    NARCIS (Netherlands)

    Van Der Beek, J. G. ( Hans); Punacker, Laas P.

    2008-01-01

    Differences in amplified fragment length polymorphisms (AFLP) between isolates and between mono-female lines of facultative automictic Meloidogyne hapla race A and obligate apomictic M incognita were determined to test the hypothesis that inverted meiosis occurs. DNA of the parthenogenetic nematode

  17. Population and molecular genetics of root-knot nematodes

    NARCIS (Netherlands)

    Dautova, M.

    2001-01-01

    This thesis describes studies of root-knot nematodes Meloidogyne spp. - an economically important pest in agriculture - using population and molecular genetics. Variability in virulence to Mi bearing tomato genotypes is shown for

  18. Expression of Phenylalanine Ammonia Lyase Genes in Maize Lines Differing in Susceptibility to Meloidogyne incognita

    OpenAIRE

    Starr, J. L.; Yang, W.; Yan, Y.; Crutcher, F.; Kolomiets, M.

    2014-01-01

    Maize is a well-known host for Meloidogyne incognita, and there is substantial variation in host status among maize genotypes. In previous work it was observed that nematode reproduction increased in the moderately susceptible maize inbred line B73 when the ZmLOX3 gene from oxylipid metabolism was knocked out. Additionally, in this mutant line, use of a nonspecific primer for phenyl alanine ammonialyase (PAL) genes indicated that expression of these genes was reduced in the mutant maize plant...

  19. Resistance to Root-knot Nematodes in Cucumber and Horned Cucumber

    OpenAIRE

    Wehner, Todd C.; Walters, S. Alan; Barker, Kenneth R.

    1991-01-01

    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 sus...

  20. Evaluation of Dry Ice as a Potential Cryonematicide for Meloidogyne incognita in Soil

    OpenAIRE

    Wergin, William P.; Yaklich, Robert W.; Chitwood, David J.; Erbe, Eric F.

    1999-01-01

    Solid CO₂ (dry ice) was added to pots containing soil that was infested either with eggs of the root-knot nematode, Meloidogyne incognita, or with tomato (Lycopersicon esculentum 'Rutgers') root fragments that were infected with various stages of the nematode. Two hours after dry ice was added, thermocouples in the soil recorded temperatures ranging from -15 °C to -59 °C. One day after treatment with the dry ice, the temperature of the soil was allowed to equilibrate with that of the greenhou...

  1. Biological Control of Meloidogyne hapla Using an Antagonistic Bacterium

    Directory of Open Access Journals (Sweden)

    Jiyeong Park

    2014-09-01

    Full Text Available We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN Meloidogyne hapla in carrot (Daucus carota subsp. sativus and tomato (Solanum lycopersicum. Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.

  2. Predicting Damage of Meloidogyne incognita on Watermelon

    Science.gov (United States)

    Xing, Lijuan; Westphal, Andreas

    2012-01-01

    Quantitative growth response of watermelon (Citrullus lanatus) sensitive to Meloidogyne incognita is poorly understood. Determination of soil population densities of second-stage juveniles (J2) of M. incognita with Baermann funnel extraction often is inaccurate at low soil temperatures. In greenhouse experiments, three sandy soils were inoculated with dilution series of population densities of eggs or J2 of M. incognita and planted in small containers to watermelon ‘Royal Sweet’ or subjected to Baermann funnel extraction. After five weeks of incubation in the greenhouse bioassay plants in egg-inoculated soils, gall numbers on watermelon roots related more closely to inoculated population densities than J2 counts after Baermann funnel extraction. In April 2004, perpendicularly-inserted tubes (45-cm diameter, 55-cm deep) served as microplots where two methyl bromide-fumigated sandy soils were inoculated with egg suspensions of M. incognita at 0, 100, 1,000 or 10,000 eggs/100 cm3 of soil in 15-cm depth. At transplanting of 4-week old watermelon seedlings, soils were sampled for the bioassay or for extraction of J2 by Baermann funnel. In the Seinhorst function of harvested biomass in relation to nematode numbers, decline of biomass with increasing population densities of M. incognita was accurately modeled by the inoculated eggs (R2 = 0.93) and by the counts of galls on the bioassay roots (R2 = 0.98); but poorly by J2 counts (R2 = 0.68). Threshold levels of watermelon top dry weight to M. incognita were 122 eggs/100 cm3 soil, 1.6 galls on bioassay roots, or 3.6 J2/100 cm3 of soil. Using the bioassay in early spring for predicting risk of nematode damage appeared useful in integrated pest management systems of watermelon. PMID:23482631

  3. Inhibitory effects of salicylic acid on Meloidogyne javanica reproduction in tomato plants

    Energy Technology Data Exchange (ETDEWEB)

    Moslemi, F.; Fatemy, S.; Bernard, F.

    2016-11-01

    Root-knot nematodes (Meloidogyne spp.), play a major role in loss of agricultural production. Natural substances, such as salicylic acid (SA) could possibly be involved in inducing host plant resistance against nematodes. The present study is concerned with exploring the effects of varying concentrations of SA as seed priming and soil drench on tomato growth parameters and the reproduction of the root-knot nematode Meloidogyne javanica. SA at 50 μM concentration caused only 2% of juvenile mortality under in vitro conditions. SA applied as 50 μM seed treatment caused 95% and, as a soil drench, 78% reduction in the number of egg masses that formed on tomato plants. The numbers of galls were reduced to a lesser extent. Final nematode density per gram of soil was reduced to less than 1 by the 50 μM SA seed treatment, and in other treatments decreased by between 70 and 88% compared with control plants. Our results indicate SA has potential to lower root knot nematode reproduction in tomato, and seed priming is a fairly easy method to work with. (Author)

  4. Mixtures of Olive Pomace with Different Nitrogen Sources for the Control of Meloidogyne spp. on Tomato

    Science.gov (United States)

    Rodríguez-Kábana, R.; Estaún, V.; Pinochet, J.; Marfá, O.

    1995-01-01

    The efficacy of mixtures of dry olive (Olea europea) pomace with biuret, guanidine, and melamine for control of root-knot nematodes (Meloidogyne spp.) on tomato (Lycopersicon esculentum) was studied in greenhouse experiments. Olive pomace (OP) applied pre-plant at 10 g/kg soil was phytotoxic. Mixtures of OP (10 g/kg soil) with biuret or guanidine at 200-300 mg/kg soil reduced or eliminated the phytotoxic effect, controlled root-knot nematodes, and increased soil esterase activity indicative of microbial activity. The addition of biuret or guanidine without OP to soil at rates <300 mg/kg soil did not control root-knot nematodes. Melamine applied at 100-400 mg/kg soil was phytotoxic as were mixtures of melamine with OP. Treatment of OP with anhydrous ammonia increased N content of the material. In another greenhouse experiment, NH₃-treated OP added to soil was not phytotoxic to tomato, suppressed root-knot nematodes, and increased soil esterase activity. Greenhouse and microplot experiments with OP plus chicken litter demonstrated the efficacy of these combination amendments to control root-knot nematodes and increase tomato yields in Meloidogyne-infested soil. PMID:19277325

  5. Mixtures of Olive Pomace with Different Nitrogen Sources for the Control of Meloidogyne spp. on Tomato.

    Science.gov (United States)

    Rodríguez-Kábana, R; Estaún, V; Pinochet, J; Marfá, O

    1995-12-01

    The efficacy of mixtures of dry olive (Olea europea) pomace with biuret, guanidine, and melamine for control of root-knot nematodes (Meloidogyne spp.) on tomato (Lycopersicon esculentum) was studied in greenhouse experiments. Olive pomace (OP) applied pre-plant at 10 g/kg soil was phytotoxic. Mixtures of OP (10 g/kg soil) with biuret or guanidine at 200-300 mg/kg soil reduced or eliminated the phytotoxic effect, controlled root-knot nematodes, and increased soil esterase activity indicative of microbial activity. The addition of biuret or guanidine without OP to soil at rates <300 mg/kg soil did not control root-knot nematodes. Melamine applied at 100-400 mg/kg soil was phytotoxic as were mixtures of melamine with OP. Treatment of OP with anhydrous ammonia increased N content of the material. In another greenhouse experiment, NH-treated OP added to soil was not phytotoxic to tomato, suppressed root-knot nematodes, and increased soil esterase activity. Greenhouse and microplot experiments with OP plus chicken litter demonstrated the efficacy of these combination amendments to control root-knot nematodes and increase tomato yields in Meloidogyne-infested soil.

  6. Tagetes Patula y T Erecta para Controlar Meloidogyne Incognita y Hellcotylenchus Dihystera

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    Vergel German

    1979-06-01

    Full Text Available An experiment was carried out under greenhouse conditions to test the control of Meloidogyne incognita and Helicotylenchus dihystera by Tagetes patula nana var. Petit Harmony and T. erecta var. Orange. For each of these nematode species, the population levels tested were considered as high, moderate and low. These populations were obtained mixing infested soil with sterilized one. Both Tagetes species gave satisfactory control. The decrease in population of nematodes in comparison with tomato was ranged from 15.5 to 136.3% depencing on the nematode species and on its population level on the soil No significate difference was found between the two Tagetes species. There was a greater decrease in population density for M. incognita than for H. dihystera; this was particulary true at the lowest population levels tested. In the case of M. incognita, an inverse relation was found between degree of control and population density of these nematodes in soil.

  7. REAÇÃO DE GENÓTIPOS DE MILHO (Zea mays L. AOS NEMATÓIDES DE GALHAS (Meloidogyne javanica e M. incognita REACTION OF CORN GENOTYPES (Zea mays L. TO ROOT-KNOT NEMATODES (Melodoigyne javanica and M. incognita

    Directory of Open Access Journals (Sweden)

    Hércules Diniz Campos

    2007-09-01

    ="justify">Two experiments were carried out under greenhouse conditions with the objective of evaluating the reaction of eight corn genotypes to the root-knot nematodes Meloidogyne javanica and M. incognita. Cultivars HATÃ-1001, HATÃ-1045, DINA-657 and FT-5140 presented smaller reproduction factors (RF for M. javanica. Therefore, the use of these cultivars may be indicated in the crop rotation program with soybean. All cultivars were suitable hosts for M. incognita, presenting RF higher than 3.98.

    KEY-WORDS: Resistance; root-knot; nematodes; corn.

  8. Meloidogyne and Pratylenchus species in sugarcane fields in the state of Alagoas, Brazil

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    Marissônia de Araujo Noronha

    Full Text Available ABSTRACT: The objective of this study was to accomplish a survey on populations of Meloidogyne and Pratylenchus species in sugarcane farming areas in the state of Alagoas, Brazil. Twenty samples of soil and roots were processed to extract and quantify nematodes; however, the identification of Meloidogyne species was performed using only 12 samples. Pratylenchus spp. were reported at moderate population levels of 68-1556 specimens 50g-1 of roots and 2-298 specimens 100cm-3 of soil in twenty analyzed samples. For Meloidogyne spp., these values were of 12-487 specimens 50g-1 of roots and 0-140 specimens 100cm-3 of soil. Based on electrophoresis of esterase isozymes, M. incognita was reported to be the most frequent species, followed by M. javanica and M. arenaria. Pratylenchus species identified through morphometrical and morphological characteristics were P. zeae and P. brachyurus , with predominance for the first species. No significant correlation (P≤0.05 were reported between nematode populations and sugarcane cropping systems.

  9. Biology of Meloidogyne platani Hirschmann Parasitic on Sycamore, Platanus occidentalis.

    Science.gov (United States)

    Al-Hazmi, A S; Sasser, J N

    1982-04-01

    The development of Meloidogyne platani on sycamore was followed for 40 days (22-28 C). Juveniles penetrated the feeder roots behind the root cap and invaded the vascular cylinder within 3 days after inoculation. All subsequent development of the nematodes and host effects occurred only within the stele. The second juvenile molt and sex differentiation occurred by the 17th day. Young females were observed by the 26th day. Eggs were observed inside the roots by the 35th day and were exposed to the surface of galls by the 40th day. In pathogenicity studies, a significant negative correlation was shown to exist between fresh shoot and root weights and inoculum density. Besides sycamore, white ash was the only hardwood species tested to become infected. Of the herbacious plants tested, tobacco was heavily galled, tomato and watermelon moderately galled, and pepper only slightly galled. Egg production was moderate on tobacco, slight on tomato and watermelon, and absent on pepper.

  10. Greenhouse and field assessment of different organic compounds against guava-parasitic Meloidogyne enterolobii

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    Alexandre Macedo Almeida

    2012-01-01

    Full Text Available Guava decline is a complex disease involving Meloidogyne enterolobii and Fusarium solani and it has caused major direct losses to Brazilian growers. Although several strategies have been sought to control the nematode, the use of organic soil amendments is currently the best approach to manage this disease. To assess the best amount of meat and bone meal (MBM to be incorporated into the soil, guava seedlings inoculated with M. enterolobii were treated with 1-5% v/v of the MBM. Ninety days later variables related to nematode reproduction and plant development were evaluated, which indicated a potential nematicidal effect of the MBM at 3%. Another experiment assessed nematode- and plant-related variables 90 days after treatment of the seedlings with MBM, chitosan, shrimp shell or neem cake at 3%, 0.05%, 2% and 0.1% v/v, respectively. The MBM ranked first, reducing nematode reproduction. This MBM rate was converted to 25 kg/tree and assessed in three application regimes (monthly, bimonthly or trimonthly, for six months, in an orchard affected by guava decline. The variables assessed were soil density of colony forming units (CFU of bacteria and fungus, and soil and/or root density of M. enterolobii, Helicotylenchus sp., and of different nematode trophic groups. In all three application regimes the MBM reduced all plant-parasitic nematodes in the soil and the fungus CFUs. It also promoted an increase in bacterial CFU and bacterivorous nematodes.

  11. Resistance of Commercial Tomato Cultivars to Meloidogyne arenaria and M. incognita

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    Donggeun Kim

    2013-03-01

    Full Text Available Root-knot nematodes (Meloidogyne spp. are among the main pathogens of greenhouse crops worldwide.Plant resistance is currently the method of choice for controlling these pests. To select resistant tomato againsttwo common species of root-knot nematodes, M. incognita and M. arenaria, 36 commercial tomato(Lycopersicon esculentum Mill. cultivars were screened. Seventeen tomato cultivars were resistant to bothroot-knot nematodes: six in cherry tomato, ‘Tenten’, ‘Cadillac’, ‘Cutti’, ‘Sweet’, ‘Ppotto’, ‘Lycopin-9’, eightin globe tomato, ‘Lovely 240’, ‘Dotaerang Dia’, ‘Cupirang’, ‘Dotaerang Master’, ‘Super Dotaerang’,‘Dotaerang Season’, ‘Miroku’, ‘Hoyong’, and three in root stock, ‘Special’, ‘Fighting’, and ‘Magnet’.

  12. Dehydrogenases, Acid and Alkaline Phosphatases, and Esterases for Chemotaxonomy of Selected Meloidogyne, Ditylenchus, Heterodera and Aphelenchus spp.

    Science.gov (United States)

    Dickson, D W; Huisingh, D; Sasser, J N

    1971-01-01

    Various taxonomically useful profiles of four dehydrogenases (lactate, malate, glucose-6-phosphate, and a-glycerophosphate) and three hydrolases (acid and alkaline phosphatase and esterase) were detected in whole nematode homogenates of Meloidogynejavanica, M. hapla, M. incognita, M. arenaria, Ditylenchus dipsaci, D. triformis, Heterodera glycines, and Aphelenchus avenae. The enzyme profiles were stable in populations cultured on several different hosts. A tentative enzymically-determined phylogeny of Meloidogyne is given.

  13. Resistance to Root-knot Nematodes in Cucumber and Horned Cucumber

    Science.gov (United States)

    Wehner, Todd C.; Walters, S. Alan; Barker, Kenneth R.

    1991-01-01

    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 susceptible than the horned cucumber to Meloidogyne incognita, M. javanica, and M. arenaria. All cultigens were more resistant to M. hapla than to the other root-knot nematode species. In the second experiment, best results were obtained when the test was run for 12 weeks rather than 6 weeks after planting (or 10 and 4 weeks after inoculation, respectively). All cultigens were more resistant to M. arenaria than to either M. incognita or M. javanica. PMID:19283171

  14. Top 10 plant-parasitic nematodes in molecular plant pathology.

    Science.gov (United States)

    Jones, John T; Haegeman, Annelies; Danchin, Etienne G J; Gaur, Hari S; Helder, Johannes; Jones, Michael G K; Kikuchi, Taisei; Manzanilla-López, Rosa; Palomares-Rius, Juan E; Wesemael, Wim M L; Perry, Roland N

    2013-12-01

    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 survey is composed of: (1) root-knot nematodes (Meloidogyne spp.); (2) cyst nematodes (Heterodera and Globodera spp.); (3) root lesion nematodes (Pratylenchus spp.); (4) the burrowing nematode Radopholus similis; (5) Ditylenchus dipsaci; (6) the pine wilt nematode Bursaphelenchus xylophilus; (7) the reniform nematode Rotylenchulus reniformis; (8) Xiphinema index (the only virus vector nematode to make the list); (9) Nacobbus aberrans; and (10) Aphelenchoides besseyi. The biology of each nematode (or nematode group) is reviewed briefly. © 2013 BSPP AND JOHN WILEY & SONS LTD.

  15. Potential of Tissue Culture for Breeding Root-Knot Nematode Resistance into Vegetables

    OpenAIRE

    Fassuliotis, G.; Bhatt, D. P.

    1982-01-01

    Plant protoplast technology is being investigated as a means of transferring root-knot nematode resistance factors from Solanum sisymbriifolium into the susceptible S. melongena. Solanum sisymbriifolium plants regenerated from callus lost resistance to Meloidogyne javanica but retained resistance to M. incognita. Tomato plants cloned from leaf discs of the root-knot nematode resistant 'Patriot' were completely susceptible to M. incognita, while sections of stems and leaves rooted in sand in t...

  16. Induced mutations in cucumber for resistance to nematodes (Meloidogyne spp.)

    International Nuclear Information System (INIS)

    Udalov, V.B.; Prikhod'ko, V.F.

    1989-01-01

    Full text: Seeds were treated with EI and selection was carried out over 5 years. In the susceptible cv. ''M15'' treated with 0.05% EI for 21 h 7.6% of plants were found resistant, 72% only slightly susceptible. Mutants were used in crosses and hybrids showed 57-89% resistance over 6 generations. (author)

  17. Transgressive segregation of root-knot nematode resistance in cotton determined by QTL analysis

    Science.gov (United States)

    Transgressive resistance to root-knot nematode, Meloidogyne incognita, was found in intraspecific (Gossypium hirsutum; resistant Acala NemX x susceptible Acala SJ-2) and interspecific (G. barbadense susceptible Pima-S7 x Acala NemX) cotton recombinant inbred line (RIL) populations. Similar contribut...

  18. Trapping of root-knot nematodes by the adhesive hyphae-forming fungus Arthrobotrys oligospora

    NARCIS (Netherlands)

    Belder, den E.

    1994-01-01

    The present study addresses the ecology of a particular isolate of Arthrobotrys oligospora (CBS 289.82) in relation to its efficacy in controlling the root-knot nematode, Meloidogyne hapla.

    This isolate was selected because it differs from

  19. Evaluation of edible ginger and turmeric cultivars for root-knot nematode resistance

    Science.gov (United States)

    Edible ginger and turmeric roots are important agricultural commodities for the State of Hawaii. Bacterial wilt, Ralstonia solanacearum, and root-knot nematodes, Meloidogyne spp. are major factors hindering optimum production. An evaluation of tolerance and resistance to M. incognita was undertake...

  20. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants.

    Science.gov (United States)

    Silvestre, A; Cabaret, J

    2004-06-01

    In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control)? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation) are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole). Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy) are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial: it is not possible to avoid it, but only to delay its development in farm animal industry.

  1. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants

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    Silvestre A.

    2004-06-01

    Full Text Available In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control ? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole. Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial : it is not possible to avoid it, but only to delay its development in farm animal industry.

  2. Development of virulence to Meloidogyne incognita on resistant pepper rootstocks

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    C. Ros Ibáñez

    2014-02-01

    Full Text Available The root-knot nematode (RKN Meloidogyne incognita is a major soil parasite of pepper crops in greenhouses in Southeast Spain. Due to the limitations of the use of soil fumigants, grafting plants on resistant rootstocks (R-rootstocks has become an important alternative to chemical nematicides. The repeated use of R-rootstocks can bring about the selection of virulent populations capable of overcoming resistance. We carried out a six-year investigation on resistant rootstocks in a naturally M. incognita infested greenhouse, and found that two successive years of growing plants grafted on R-rootstocks Atlante (ATL were sufficient to overcome resistance (galling index 1.5 and 5.6 in the first and second years respectively. A large variability was observed between several R-rootstocks. Two R-rootstocks (C19 and Snooker behaved like ATL while two others (Terrano and DRO 8801 were not infected by RKN. Laboratory studies with the same R-rootstocks, inoculated with two nematode isolates (avirulent and virulent against ATL confirmed the greenhouse results, indicating that some rootstocks may be infested by virulent populations and others may not. It suggests that different R-genes, which are differentially overcome by RKN, have been introgressed into the rootstocks. This may have consequences for the management of resistant rootstocks in the field.

  3. Development of virulence to Meloidogyne incognita on resistant pepper rootstocks

    Energy Technology Data Exchange (ETDEWEB)

    Ros-Ibanez, C.; Robertson, L.; Martinez-Lluch, M. C.; Cano-Garcia, A.; Lacasa-Plasencia, A.

    2014-06-01

    The root-knot nematode (RKN) Meloidogyne incognita is a major soil parasite of pepper crops in greenhouses in Southeast Spain. Due to the limitations of the use of soil fumigants, grafting plants on resistant rootstocks (R-rootstocks) has become an important alternative to chemical nematicides. The repeated use of R-rootstocks can bring about the selection of virulent populations capable of overcoming resistance. We carried out a six-year investigation on resistant rootstocks in a naturally M. incognita infested greenhouse, and found that two successive years of growing plants grafted on R-rootstocks Atlante (ATL) were sufficient to overcome resistance (galling index 1.5 and 5.6 in the first and second years respectively). A large variability was observed between several R-rootstocks. Two R-rootstocks (C19 and Snooker) behaved like ATL while two others (Terrano and DRO 8801) were not infected by RKN. Laboratory studies with the same R-rootstocks, inoculated with two nematode isolates (avirulent and virulent against ATL) confirmed the greenhouse results, indicating that some rootstocks may be infested by virulent populations and others may not. It suggests that different R-genes, which are differentially overcome by RKN, have been introgressed into the rootstocks. This may have consequences for the management of resistant rootstocks in the field. (Author)

  4. REPRODUÇÃO DE Meloidogyne incognita RAÇA 2 E DE Meloidogyne javanica EM OITO ESPÉCIES DE PLANTAS MEDICINAIS

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    S.L. MACIEL

    1996-05-01

    Full Text Available Avaliaram-se as taxas reprodutivas de Meloidogyne incognita raça 2 e de Meloidogyne javanica em oito espécies de plantas consideradas medicinais, em vasos com 500 ml de solo, sob condição de casa de vegetação. Cada planta foi inoculada com 5000 ovos, em média, estabelecendo-se cinco repetições. Realizaram-se as avaliações após 45 a 55 dias das inoculações, com base nos índices de massas de ovos e nos fatores de reprodução dos nematóides. Achillea millefolium (mil-folhas, Arctium lappa (bardana, Bryophyllum calycinum (folha-da-fortuna e Crassula portulacea (bálsamo foram hospedeiras não eficientes ou desfavoráveis a ambas as espécies. Plectranthus barbatus (boldo e Polygonum hidropiperoides (polígono foram eficientes à reprodução das duas espécies. Achyrocline satureoides (macela e Tropaeolum majus (chagas foram eficientes para M. javanica e não para M. incognita.The reproductive rates of the root-knot nematodes Meloidogyne incognita race 2 and M. javanica in the roots of eight medicinal plant species were assessed under greenhouse condition. Each plant, growing in a pot containing 500 ml of sterilized soil, was inoculated with an average number of 5,000 eggs, with five repetitions. Egg mass index and reproduction factor data were used for the evaluation, 45-55 days after plant inoculation. Achillea millefolium, Arctium lappa, Bryophyllum calycinum, and Crassula portulacea were rated as poor or nonefficient hosts, while Plectranthus barbatus and Polygonum hidropiperoides were efficient for both nematode species. Achyrocline satureoides and Tropaeolum majus were efficient for M. javanica, but nonefficient for M. incognita.

  5. Nematicides control rice root-knot, caused by Meloidogyne graminicola

    Directory of Open Access Journals (Sweden)

    Mujeebur Rahman KHAN

    2012-09-01

    Full Text Available Studies were conducted to determine damage potential of Meloidogyne graminicola on the commonly grown rice cv. Sugandh-5 and to devise an effective management strategy. The nematicides were applied through root-dip (200 ppm solution and soil application of 2 kg ha-1 phorate 10G (25 mg a.i./pot, carbofuran 3G (83.3 mg a.i./pot and 1 L ha-1, carbosulfan 20EC (5µL/pot and chlorpyriphos 20 EC (6.25 µL/pot in both nematode infested and non-infested soil with five modes of application viz., root-dip, single soil application (15 days after transplanting, root-dip + one soil application, two soil applications, and root-dip + two soil applications (15 and 30 days. Application of nematicides did not cause any toxicity symptoms on rice plants. In nematode infested soil, terminal and spiral galls developed on the rice roots, and plants suffered 20−31% decrease in the plant growth parameters. Carbofuran and phorate through root-dip plus single soil application provided greatest suppression in galling (16−20%, egg mass production (18−22% and soil population (27.5−58.2% of M. graminicola, and subsequently increased all the plant growth variables by 9−19%. Root-dip + two soil applications increased plant growth and suppressed nematodes, but was equal to root dip + one soil application. Root-dip treatment alone with carbosulfan also significantly suppressed root galling (10−12% and improved the dry weight of roots and shoots (7−10%.

  6. Efecto de la incorporación de plantas antagónicas sobre la actividad parasítica del nematodo del nudo de la raíz Meloidogyne hapla en un cultivo de zanahoria bajo condiciones de invernadero Effect of the incorporation of antagonistic plants on the parasitic activity of the root-knot nematode Meloidogyne hapla in a greenhouse carrot crop

    Directory of Open Access Journals (Sweden)

    Alvarez César G.

    1998-12-01

    Full Text Available En el Centro de Investigaciones y Asesorías Agroindustriales (CIAA de la Universidad Jorge Tadeo Lozano, localidad de Chía (Cundinamarca, se llevó a cabo un ensayo bajo condiciones de invernadero para evaluar el efecto de la incorporación de material vegetal fresco proveniente de siete especies de plantas (Tagetes zipaquirensis, T. erecta, Brassica cempestris, Bidens pilosa, Ruta graveolens, Taraxacum officinale y Ricinus communis sobre el rendimiento y calidad comercial de un cultivo de zanahoria (Daucus carota varo Mokum y sobre la densidad poblacional del nemátodo del nudo de la raíz Meloidogyne hapla y la intensidad de la nodulación asociada con su establecimiento sobre plantas de zanahoria. No se encontraron diferencias significativas en cuanto al rendimiento biológico de la zanahoria, pero los tratamientos con R. graveolens y T. officinale mostraron la mayor producción de zanahoria comercial (3070 g.m·2 y 2270 g.m·2 con diferencias significativas respecto al testigo (1090 g.m-2. Las densidades poblacionales finales de juveniles infectivos [J2] de M. hapla fueron significativamente más bajas en los tratamientos con R. communis, T. officinale, B. campestris y T. erecta (65-130 J2/100 g de suelo que en el testigo (435 J2/100g de suelo. En la nodulación se encontraron diferencias significativas entre el testigo (5.0 nudos/ápice de zanahoria y los demás tratamientos (1,9-2,6 nudos/ápice de zanahoria.A trial was conducted at the Centro de Investigaciones y Asesorías Agroindustriales (CIAA of the Universidad Jorge Tadeo Lozano, Chía (Cundinamarca under greenhouse conditions to assess the effect of incorporating fresh above-ground material of seven plant species (Tagetes zipaquirensis, T. erecta, Brassica cempestris. Bidens pilosa, Rufa graveolens, Taraxacum officinale and Ricínus communis on the yield and commercial quality of a carrot (Daucus carota crop var. Mokum, on the population density of Meloidogyne hapla and on the

  7. Effects of Tomato Root Exudates on Meloidogyne incognita.

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    Guodong Yang

    Full Text Available Plant root exudates affect root-knot nematodes egg hatch. Chemicals in root exudates can attract nematodes to the roots or result in repellence, motility inhibition or even death. However, until recently little was known about the relationship between tomato root exudates chemicals and root-knot nematodes. In this study, root exudates were extracted from three tomato rootstocks with varying levels of nematode resistance: Baliya (highly resistant, HR, RS2 (moderately resistant, MR and L-402 (highly susceptible, T. The effects of the root exudates on Meloidogyne incognita (M. incognita egg hatch, survival and chemotaxis of second-stage juveniles (J2 were explored. The composition of the root exudates was analysed by gas chromatography/mass spectrometry (GC/MS prior to and following M. incognita inoculation. Four compounds in root exudates were selected for further analysis and their allopathic effect on M. incognita were investigated. Root exudates from each tomato rootstocks (HR, MR and T strains suppressed M. incognita egg hatch and increased J2 mortality, with the highest rate being observed in the exudates from the HR plants. Exudate from HR variety also repelled M. incognita J2 while that of the susceptible plant, T, was demonstrated to be attractive. The relative amount of esters and phenol compounds in root exudates from HR and MR tomato rootstocks increased notably after inoculation. Four compounds, 2,6-Di-tert-butyl-p-cresol, L-ascorbyl 2,6-dipalmitate, dibutyl phthalate and dimethyl phthalate increased significantly after inoculation. The egg hatch of M. incognita was suppressed by each of the compound. L-ascorbyl 2,6-dipalmitate showed the most notable effect in a concentration-dependent manner. All four compounds were associated with increased J2 mortality. The greatest effect was observed with dimethyl phthalate at 2 mmol·L-1. Dibutyl phthalate was the only compound observed to repel M. incognita J2 with no effect being detected in

  8. Host status of progenies of yellow passion fruit to Meloidogyne incognita race 2

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    Roxana Stefane Mendes Nascimento

    2016-07-01

    Full Text Available The host status of eighteen progenies (CRP 01-12 to CRP 16-12, CRP 19-12 and CRP 20-12 and two cultivars (FB 200 Yellow Master and FB 300 Araguari of yellow passion fruit to Meloidogyne incognita race 2 was evaluated in a greenhouse experiment. The height and the biomass of the plants, besides the numbers of galls, eggs and second-stage juveniles in roots and soil were assessed after 70 days of cultivation of the genotypes and tomato (control in plastic pots with 2 kg of soil infested with 5,000 eggs of the nematode. The reproduction factor of the pathogen (RF = Final population/Initial population was calculated for classifying the genotypes as immune (RF = 0, resistant (RF < 1 or susceptible (RF ≥ 1. The cultivar FB 200 is resistant to M. incognita race 2 and can be cultivated in areas infested with this nematode.

  9. Effect of Artemisia vulgaris Rhizome Extracts on Hatching, Mortality, and Plant Infectivity of Meloidogyne megadora.

    Science.gov (United States)

    da R Costa, S Dos S; de A Santos, M S N; Ryan, M F

    2003-12-01

    The activity of an ethanolic rhizome extract of Artemisia vulgaris against hatching, mortality, host plant infectivity, and galling of the root-knot nematode Meloidogyne megadora was investigated. The extract inhibited egg hatch (50% inhibition by 2.35mg/ml) and caused second-stage juvenile mortality (50% lethality at 12 hours' exposure to 55.67 mg/ml), both in a dose-dependent manner. Nematode infectivity on Phaseolus vulgaris 'Bencanta Trepar', a susceptible host, decreased in a dose-responsive manner (50% inhibition at 6.28 hours exposure to extract). When applied directly to the soil, the extract reduced root galling on a susceptible host in a dose-dependent manner (50% inhibition by 32.36 mg/ml). After dilution in distilled water, the extract did not lose activity when stored in the dark at 25 degrees C for 15 days.

  10. Interaction between Meloidogyne incognita and Agrobacterium tumefaciens or Fusarium oxysporum f. sp. lycopersici on Tomato

    Science.gov (United States)

    El-Sherif, Ahmed G.; Elwakil, M. A.

    1991-01-01

    Agrobacterium tumefaciens stimulated and Fusarium oxysporum f. sp. lycopersici inhibited development and reproduction of Meloidogyne incognita when applied to the opposite split root of tomato, Lycopersicon esculentum cv. Tropic, plants. The lowest rate of nematode reproduction occurred after 2,000 juveniles were applied and the fungus was present in the opposite split root. The effects of all three pathogens alone on the growth of roots and shoots of tomato plants were evident, but M. incognita had a greater effect alone than did either of the other pathogens. The length of split roots was reduced by the infection of M. incognita and A. tumefaciens or F. oxysporum f. sp. lycopersici. The number of galls induced by nematodes on roots was higher where the bacterium was applied and lower where the fungus was applied to the opposite split root. PMID:19283119

  11. Reprodução de Meloidogyne spp. em porta-enxertos e híbridos de pepino Reproduction of Meloidogyne spp. in rootstocks and cucumber hybrids

    Directory of Open Access Journals (Sweden)

    Silvia Renata S Wilcken

    2010-03-01

    Full Text Available A enxertia é uma técnica alternativa frequentemente recomendada para a cultura do pepino em áreas infestadas com nematóides das galhas. O presente trabalho teve como objetivo determinar o fator de reprodução de Meloidogyne javanica e de Meloidogyne incognita raça 2 em seis porta-enxertos para pepino (abóbora 'Menina Brasileira', moranga 'Exposição', 'Shelper', 'Tetsukabuto', 'B8-A Tetsukabuto' e 'Excite Ikki' e quatro híbridos de pepino (Cucumis sativus tipo japonês ('Yoshinari', 'Kouki', 'Taisho' e 'Tsuyataro'. Foram conduzidos dois experimentos em casa-de-vegetação, um com cada espécie do nematóide, sendo cada parcela constituída de uma planta mantida em vaso contendo 2 litros de solo autoclavado. Nove dias após transplante, cada planta foi inoculada com 5.000 ovos e juvenis de segundo estádio (população inicial - Pi de M. javanica ou M. incognita raça 2. Tomateiros 'Rutgers' foram utilizados como padrão de viabilidade do inóculo, em ambos os experimentos. O delineamento experimental foi inteiramente casualizado com cinco repetições por tratamento. Sessenta dias após a inoculação, cada planta foi avaliada, quanto ao peso fresco da raiz, número total de nematóides presentes no solo e na raiz (população final - Pf, número de nematóides/g de raiz e fator de reprodução de ambas as espécies de Meloidogyne (FR=Pf/Pi. Todos os porta-enxertos e híbridos de pepino testados apresentaram fatores de reprodução superiores a um, proporcionando a multiplicação de M. javanica e de M. incognita raça 2, porém, os valores nos híbridos de pepino foram superiores aos dos porta-enxertos.Grafting is an alternative technique often recommended for the cucumber crop in root-knot nematodes infested areas. This study aimed to determine the reproduction factor of Meloidogyne javanica and M. incognita race 2 on six rootstocks for cucumber (squash 'Menina Brasileira, pumpkim 'Exposição', 'Shelper', 'Tetsukabuto', 'B8-A

  12. Both SSU rDNA and RNA polymerase II data recognise that root-knot nematodes arose from migratory Pratylenchidae, but probably not from one of the economically high-impact lesion nematodes

    NARCIS (Netherlands)

    Rybarczyk-Mydlowska, K.; Megen, van H.H.B.; Elsen, van den S.J.J.; Mooijman, P.J.W.; Karssen, G.; Bakker, J.; Helder, J.

    2014-01-01

    In 2000 Siddiqi formulated a hypothesis stating that root-knot nematodes (Meloidogyne spp.) constitute a branch arising from yet another important group of plant parasites, the migratory Pratylenchidae. This hypothesis was solely based on morphological characteristics. Ribosomal DNA (rDNA) sequence

  13. Resistance of sweet potato clones to meloidogyne incognita races 1 and 3

    Directory of Open Access Journals (Sweden)

    Jorge Augusto Assis Gomes

    2015-09-01

    Full Text Available The objective of this study was to evaluate sweet potato clones for resistance to root-knot nematode, Meloidogyne incognita races 1 and 3. For each nematode physiological race, a greenhouse experiment was set up in a randomized block experimental design with three replications and six plants per plot. Fifty-eight sweet potato clones from the UFVJM germplasm bank were evaluated, plus five commercial cultivars (Brazlândia Rosada, Brazlândia Branca, Palmas, Princesa and Coquinho, plus the cv. Santa Clara tomato (susceptible to Meloidogyne spp.. Stems were planted in 72-cell expanded polystyrene trays, filled with commercial substrate and inoculated with the pathogen thirty days after planting. Forty-five days after inoculation, the eggs were extracted, counted, and later evaluated. Resistance level classification was performed based on reproduction factor (RF and reproduction index (RI. Among the 63 analyzed clones, a percentage of 78% were classified as resistant to M. incognita race 1.79% to race 3 and 67% showed multiple resistance to both M. incognita races.

  14. Resistance of sweet potato clones to meloidogyne incognita races 1 and 3

    Directory of Open Access Journals (Sweden)

    Jorge Augusto Assis Gomes

    2015-01-01

    Full Text Available The objective of this study was to evaluate sweet potato clones for resistance to root-knot nematode, Meloidogyne incognita races 1 and 3. For each nematode physiological race, a greenhouse experiment was set up in a randomized block experimental design with three replications and six plants per plot. Fifty-eight sweet potato clones from the UFVJM germplasm bank were evaluated, plus five commercial cultivars (Brazlândia Rosada, Brazlândia Branca, Palmas, Princesa and Coquinho, plus the cv. Santa Clara tomato (susceptible to Meloidogyne spp.. Stems were planted in 72-cell expanded polystyrene trays, filled with commercial substrate and inoculated with the pathogen thirty days after planting. Forty-five days after inoculation, the eggs were extracted, counted, and later evaluated. Resistance level classification was performed based on reproduction factor (RF and reproduction index (RI. Among the 63 analyzed clones, a percentage of 78% were classified as resistant to M. incognita race 1.79% to race 3 and 67% showed multiple resistance to both M. incognita races.

  15. Identification of Meloidogyne species associated with upland ornamentals plants in Costa Rica.

    Directory of Open Access Journals (Sweden)

    Stefany Solano-González

    2015-06-01

    Full Text Available The objective of this study was to identify nematodes species of the genus Meloidogyne associated with upland ornamental plants. We sampled ten ornamental species in a commercial nursery in San Isidro, Heredia, Costa Rica between 2011-2012. Morphometric measurements of the stylet length, the tail length, and the hyaline region of J2s, as well as perineal patterns of egg-carrying females were used for identification, Genomic DNA was extracted from single J2s and molecular analyses were performed by amplifying the intergenic region between cytochrome oxidase subunit II of the COII and the long subunit of the ARN ribosomal genes by PCR-RFLP. Combining these methods allowed identification of five species of nematodes of the genus Meloidogyne (M. arenaria, M. hapla, M. hispanica, M. incognita and M. javanica, and new restriction enzyme patterns were reported for M. hapla and M. javanica using AluI. Additionally, a preliminary report of M. hispanica was described by sequencing the 28S and 18S regions.

  16. Identification of Meloidogyne species associated with uptall ornamentals plants in Costa Rica

    International Nuclear Information System (INIS)

    Solano-Gonzalez, Stefany; Esquivel-Hernandez, Alejandro; Molina-Bravo, Ramon; Morera-Brenes, Bernal

    2015-01-01

    Nematodes species of the genus Meloidogyne associated with upland ornamental plants were identified. Ten ornamental species in a commercial nursery were sampled in San Isidro, Heredia, Costa Rica between 2011-2012. Morphometric measurements of the stylet length, the trail length, and the hyaline region of J 2 s as well as perineal patterns of egg-carrying females were used for identification, Genomic DNA was extracted from single J 2 s and molecular analyses were performed by amplifying the intergenic region between cytochrome oxidase subunit II of the COII and the long subunit of the ARN ribosomal genes by PCR-RFLP. Combining these methods allowed identification of five species of nematodes of the genus Meloidogyne (M. arenaria, M. hapla, M. hispanica, M. incognita and M. javanica), and new restriction enzyme patterns were reported for M. hapla and M. javanica using AluI. Additionally a preliminary report of M. hispanica was described by sequencing the 28S and 18S regions. (author) [es

  17. Species of root-knot nematodes and fungal egg parasites recovered from vegetables in Almería and Barcelona, Spain

    OpenAIRE

    Verdejo Lucas, Soledad; Ornat Longarón, Cèsar; Sorribas Royo, Francisco Javier; Stchigel, Alberto Miguel

    2002-01-01

    Intensive vegetable production areas were surveyed in the provinces of Almería (35 sites) and Barcelona (22 sites), Spain, to determine the incidence and identity of Meloidogyne spp. and of fungal parasites of nematode eggs. Two species of Meloidogyne were found in Almería—M. javanica (63% of the samples) and M. incognita (31%). Three species were found in Barcelona, including M. incognita (50%), M. javanica (36%), and M. arenaria (14%). Solanaceous crops supported larger (P < 0.05) nematode ...

  18. Identification of root-knot nematode species occurring in South Africa using the SCAR-PCR technique

    NARCIS (Netherlands)

    Fourie, H.; Zijlstra, C.; Mc Donald, A.H.

    2001-01-01

    Species of root-knot nematodes occurring in South Africa (Meloidogyne fallax, M. chitwoodi, M. javanica, M. incognita, M. arenaria and M. hapla) were identified and differentiated by the sequence characterised amplified region - polymerase chain reaction (SCAR-PCR) technique. Multiplex internal

  19. Identification de marques épigénétiques chez le nématode à galles parasite de plantes Meloidogyne incognita

    OpenAIRE

    Pratx, Loris

    2017-01-01

    Meloidogyne incognita is the most damaging plant-parasitic nematode in agriculture. M. incognita reproduces in an asexual way by obligatory parthenogenesis. Genetically identical individuals develop from females and form clonal populations. Although these clones share the same genetic heritage, modifications of their phenotype can be observed when they are exposed to unfavorable environments. This phenotypic plasticity is characterized through two phenotypes of interest: sex-differentiation a...

  20. Activity of chalcones derived from 2,4,5-trimethoxybenzaldehyde against Meloidogyne exigua and in silico interaction of one chalcone with a putative caffeic acid 3-O-methyltransferase from Meloidogyne incognita.

    Science.gov (United States)

    Nunes, Alexandro Silva; Campos, Vicente Paulo; Mascarello, Alessandra; Stumpf, Taisa Regina; Chiaradia-Delatorre, Louise Domenghini; Machado, Alan Rodrigues Teixeira; Santos Júnior, Helvécio Martins; Yunes, Rosendo Augusto; Nunes, Ricardo José; Oliveira, Denilson Ferreira

    2013-12-01

    Meloidogyne exigua is a parasitic nematode of plants that causes great losses to coffee farmers. In an effort to develop parasitic controls, 154 chalcones were synthesized and screened for activity against this nematode. The best results were obtained with (2E)-1-(4'-nitrophenyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (6) with a 50% lethal concentration (LC50) of 171 μg/ml against M. exigua second-stage juveniles, in comparison to the commercially-available nematicide carbofuran which had an LC50 of 260 μg/ml under the same conditions. When coffee plants were used, 6 reduced the nematode population to ~50% of that observed in control plants. To investigate the mechanism of action of 6, an in silico study was carried out, which indicated that 6 may act against M. exigua through inhibition of a putative caffeic acid 3-O-methyltransferase homodimer, the amino acid sequence of which was determined by examining the genome of Meloidogyne incognita. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Elucidation of the compatible interaction between banana and Meloidogyne incognita via high-throughput proteome profiling.

    Directory of Open Access Journals (Sweden)

    Aisyafaznim Al-Idrus

    Full Text Available With a diverse host range, Meloidogyne incognita (root-knot nematode is listed as one of the most economically important obligate parasites of agriculture. This nematode species establishes permanent feeding sites in plant root systems soon after infestation. A compatible host-nematode interaction triggers a cascade of morphological and physiological process disruptions of the host, leading to pathogenesis. Such disruption is reflected by altered gene expression in affected cells, detectable using molecular approaches. We employed a high-throughput proteomics approach to elucidate the events involved in a compatible banana- M. incognita interaction. This study serves as the first crucial step in developing natural banana resistance for the purpose of biological-based nematode management programme. We successfully profiled 114 Grand naine root proteins involved in the interaction with M. incognita at the 30th- and 60th- day after inoculation (dai. The abundance of proteins involved in fundamental biological processes, cellular component organisation and stress responses were significantly altered in inoculated root samples. In addition, the abundance of proteins in pathways associated with defence and giant cell maintenance in plants such as phenylpropanoid biosynthesis, glycolysis and citrate cycle were also implicated by the infestation.

  2. Identification of Nematicidal Constituents of Notopterygium incisum Rhizomes against Bursaphelenchus xylophilus and Meloidogyne incognita

    Directory of Open Access Journals (Sweden)

    Gai Liu

    2016-09-01

    Full Text Available During a screening program for new agrochemicals from Chinese medicinal herbs, the ethanol extract of Notopterygium incisum rhizomes was found to possess strong nematicidal activity against the two species of nematodes, Bursaphelenchus xylophilus and Meloidogyne incognita. Based on bioactivity-guided fractionation, the four constituents were isolated from the ethanol extract and identified as columbianetin, falcarindiol, falcarinol, and isoimperatorin. Among the four isolated constituents, two acetylenic compounds, falcarindiol and falcarinol (2.20–12.60 μg/mL and 1.06–4.96 μg/mL, respectively exhibited stronger nematicidal activity than two furanocoumarins, columbianetin, and isoimperatorin (21.83–103.44 μg/mL and 17.21–30.91 μg/mL, respectively against the two species of nematodes, B. xylophilus and M. incognita. The four isolated constituents also displayed phototoxic activity against the nematodes. The results indicate that the ethanol extract of N. incisum and its four isolated constituents have potential for development into natural nematicides for control of plant-parasitic nematodes.

  3. Identification of Nematicidal Constituents of Notopterygium incisum Rhizomes against Bursaphelenchus xylophilus and Meloidogyne incognita.

    Science.gov (United States)

    Liu, Gai; Lai, Daowan; Liu, Qi Zhi; Zhou, Ligang; Liu, Zhi Long

    2016-09-23

    During a screening program for new agrochemicals from Chinese medicinal herbs, the ethanol extract of Notopterygium incisum rhizomes was found to possess strong nematicidal activity against the two species of nematodes, Bursaphelenchus xylophilus and Meloidogyne incognita. Based on bioactivity-guided fractionation, the four constituents were isolated from the ethanol extract and identified as columbianetin, falcarindiol, falcarinol, and isoimperatorin. Among the four isolated constituents, two acetylenic compounds, falcarindiol and falcarinol (2.20-12.60 μg/mL and 1.06-4.96 μg/mL, respectively) exhibited stronger nematicidal activity than two furanocoumarins, columbianetin, and isoimperatorin (21.83-103.44 μg/mL and 17.21-30.91 μg/mL, respectively) against the two species of nematodes, B. xylophilus and M. incognita. The four isolated constituents also displayed phototoxic activity against the nematodes. The results indicate that the ethanol extract of N. incisum and its four isolated constituents have potential for development into natural nematicides for control of plant-parasitic nematodes.

  4. Crop Rotation Studies with Velvetbean (Mucuna deeringiana) for the Management of Meloidogyne spp.

    Science.gov (United States)

    Rodríguez-Kábana, R; Pinochet, J; Robertson, D G; Wells, L

    1992-12-01

    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 nematodes. Greenhouse experiments at Auburn, Alabama, using soils infested with Heterodera glycines (race 14) + M. incognita or with H. glycines + M. arenaria (race 2) showed that, in contrast to Davis soybean, a Mexican and the Florida velvetbean accessions were not hosts for the nematodes. An experiment with 'Florunner' peanut (Arachis hypogaea) and the Florida velvetbean in a field infested with M. arenaria (race 1), near Headland, Alabama, showed that significant juvenile populations of the nematode at peanut harvest time were present only in plots with peanut. A microplot rotation experiment demonstrated that 'Black Beauty' eggplant (Solanum melongena) following the Florida velvetbean had heavier shoots and lower numbers of M. arenaria juveniles in the roots and in the soil than eggplant after Summer Crookneck squash or Davis soybean.

  5. Interplay between Carotenoids, Abscisic Acid and Jasmonate Guides the Compatible Rice-Meloidogyne graminicola Interaction

    Directory of Open Access Journals (Sweden)

    Tina Kyndt

    2017-06-01

    Full Text Available In this study, we have characterized the role of carotenoids and chlorophyll in the compatible interaction between the sedentary root knot nematode (RKN Meloidogyne graminicola and the monocot model plant rice (Oryza sativa. Previous transcriptome data showed a differential expression of carotenoid and chlorophyll biosynthesis genes in nematode-induced giant cells and gall tissue. Metabolite measurement showed that galls indeed accumulate chlorophyll a, b and carotenoids, as well as the hormone abscisic acid (ABA. When ABA was externally applied on rice plants, or when ABA-biosynthesis was inhibited, a significant increase in gall formation and nematode development was found, showing the complex role of ABA in this interaction. ABA application suppressed jasmonic acid (JA levels in the plants, while ABA-biosynthesis inhibition lead to increased JA levels confirming an antagonism between ABA and JA in rice roots. In addition, combined applications of ABA and JA showed that the ABA-effect can overcome JA-induced defense. Based on these observations, we hypothesized that the accumulation of chlorophyll and carotenoid precursors would be beneficial to nematode infection. Indeed, when chemically blocking the carotenoid biosynthesis pathway at different steps, which leads to differential accumulation of carotenoids and chlorophyll in the plants, a positive and clear link between accumulation of carotenoids and chlorophyll and rice susceptibility to RKN was detected.

  6. Grafting guava on cattley guava resistant to Meloidogyne enterolobii

    Directory of Open Access Journals (Sweden)

    Renata Rodrigues Robaina

    2015-09-01

    Full Text Available The use of resistant rootstocks could be a promising method to control nematodeMeloidogyne enterolobiiin commercial plantations of guava. The present study aimed to evaluate the success of grafting guava as a scion on accessions of cattley guava as rootstocks resistant to M. enterolobii.The treatments consisted of the rootstocks cattley guava plants (three accessions of Psidium cattleyanum and common guava (control. In the apical wedge grafting method, scion of Paluma cultivated variety was used. The experiment was arranged in a randomized block design with four treatments and five replicates, and eight plants per plot. The saplings produced as described before were planted in the field where the initial growth of the different combinations were evaluated. Graft success was observed for the control (common guava and for accessions 115 and 117 of cattley guava plants, with success rates of 63, 32 and 29%, respectively. In the field, the cattley guava used as rootstocks hampered Paluma canopy development and caused death of plants. Incompatibility of P. cattleyanumas rootstocks for P. guajavaPaluma was confirmed one year after cultivation in field.

  7. Arthrobotrys oligospora-mediated biological control of diseases of tomato (Lycopersicon esculentum Mill.) caused by Meloidogyne incognita and Rhizoctonia solani.

    Science.gov (United States)

    Singh, U B; Sahu, A; Sahu, N; Singh, R K; Renu, S; Singh, D P; Manna, M C; Sarma, B K; Singh, H B; Singh, K P

    2013-01-01

    To study the biocontrol potential of nematode-trapping fungus Arthrobotrys oligospora in protecting tomato (Lycopersicon esculentum Mill.) against Meloidogyne incognita and Rhizoctonia solani under greenhouse and field conditions. Five isolates of the nematode-trapping fungus Arthrobotrys oligospora isolated from different parts of India were tested against Meloidogyne incognita and Rhizoctonia solani in tomato (Lycopersicon esculentum Mill.) plants grown under greenhouse and field conditions. Arthrobotrys oligospora-treated plants showed enhanced growth in terms of shoot and root length and biomass, chlorophyll and total phenolic content and high phenylalanine ammonia lyase activity in comparison with M. incognita- and R. solani-inoculated plants. Biochemical profiling when correlated with disease severity and intensity in A. oligospora-treated and untreated plants indicate that A. oligospora VNS-1 offered significant disease reduction in terms of number of root galls, seedling mortality, lesion length, disease index, better plant growth and fruit yield as compared to M. incognita- and R. solani-challenged plants. The result established that A. oligospora VNS-1 has the potential to provide bioprotection agents against M. incognita and R. solani. Arthrobotrys oligospora can be a better environment friendly option and can be incorporated in the integrated disease management module of crop protection. Application of A. oligospora not only helps in the control of nematodes but also increases plant growth and enhances nutritional value of tomato fruits. Thus, it proves to be an excellent biocontrol as well as plant growth promoting agent. © 2012 The Society for Applied Microbiology.

  8. Evaluation of repeated bio disinfestation using Brassica carinata pellets to control Meloidogyne incognita in protected pepper crops

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Diaz, M. M.; Lacasa-Martinez, C. M.; Hernandez-Pinera, A.; Martinez-Alarcon, V.; Lacasa Plasencia, A.

    2013-06-01

    The nematode Meloidogyne incognita is responsible for substantial losses in greenhouse-grown peppers in southeastern Spain. This study evaluates the use of biodisinfestation (BS) (organic amendment + solarisation) as an alternative to using methyl bromide (MB) over three consecutive years to control the nematode in greenhouse conditions. Brassica carinata (BP) pellets or B. carinata (BP) + fresh sheep manure (M) were evaluated in treatments which began on two different dates (August and October) and the results were compared with MB-disinfested and untreated controls. During the third year, the gall index for BP was lower than that obtained for BP +M and in the August treatment than in the October treatment. The commercial crop of pepper fruit obtained with the biodisinfestation treatments begun in August was similar to or higher than that obtained with MB, and higher than that obtained with both October biodisinfestation treatments. The yield of the October biodisinfestation treatments was higher than that of the untreated one. In August of all the years studied, the accumulated exposure times were greater than the thresholds required to kill M. incognita populations at 15 cm depth. The incidence of the nematode did not correspond to the reduction achieved during solarisation, and seemed to increase during the crop cycle. Further studies should look at why high temperatures do not produce a sustained reduction in the populations of Meloidogyne incognita. (Author) 56 refs.

  9. Cytology of parthenogenesis of five Meloidogyne species

    NARCIS (Netherlands)

    Van der Beek, JG; Loss, JA; Pijnacker, LP

    1998-01-01

    Oogenesis was investigated using a fluorescent staining technique with Hoechst 33258 in several isolates of facultative meiotic parthenogenetic -Meloidogyne hapla race A, M. chitwoodi, M. fallax - and obligate ameiotic (mitotic) parthenogenetic - M. hapla race B, M. javanica - and isolate Xa of an

  10. (ajst) response of meloidogyne hapla to mycorrhiza

    African Journals Online (AJOL)

    opiyo

    Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, G. macrocarpum Tul and Tul and G. fasciculatum Walker and. Koske have been reported to reduce disease severity and suppress development of Meloidogyne incognita ... was done at National Agricultural Research Laboratories. (NARL). About 2kg of soil was used to ...

  11. Chemotaxis can take plant-parasitic nematodes to the source of a chemo-attractant via the shortest possible routes.

    Science.gov (United States)

    Reynolds, Andy M; Dutta, Tushar K; Curtis, Rosane H C; Powers, Stephen J; Gaur, Hari S; Kerry, Brian R

    2011-04-06

    It has long been recognized that chemotaxis is the primary means by which nematodes locate host plants. Nonetheless, chemotaxis has received scant attention. We show that chemotaxis is predicted to take nematodes to a source of a chemo-attractant via the shortest possible routes through the labyrinth of air-filled or water-filled channels within a soil through which the attractant diffuses. There are just two provisos: (i) all of the channels through which the attractant diffuses are accessible to the nematodes and (ii) nematodes can resolve all chemical gradients no matter how small. Previously, this remarkable consequence of chemotaxis had gone unnoticed. The predictions are supported by experimental studies of the movement patterns of the root-knot nematodes Meloidogyne incognita and Meloidogyne graminicola in modified Y-chamber olfactometers filled with Pluronic gel. By providing two routes to a source of the attractant, one long and one short, our experiments, the first to demonstrate the routes taken by nematodes to plant roots, serve to test our predictions. Our data show that nematodes take the most direct route to their preferred hosts (as predicted) but often take the longest route towards poor hosts. We hypothesize that a complex of repellent and attractant chemicals influences the interaction between nematodes and their hosts.

  12. Identification of plant parasitic nematodes in guava (Psidium guajava L.), at the municipality of Manizales (Caldas), Colombia

    International Nuclear Information System (INIS)

    Guzman Piedrahita, Oscar Adrian; Castano Zapata, Jairo

    2010-01-01

    The future of the colombian fruticulture is in permanent crops, such as tropical fruits, amongst them guava. This research had as objective to identify the parasitic nematodes of this crop. The study was conducted at the region of La Cabana, municipality of Manizales, Caldas, located at 1.100 most, average annual temperature of 24 Celsius degrade and annual precipitation of 2.100 mm. The sampling was carried out in a plantation of guava Pera of 3 years old. At random were sampled 10 trees, and from each one was obtained samples of 100 g of roots and 500 g of soil. The extraction of nematodes was done by following the method of centrifugation and sugar flotation. It was identified: Meloidogyne, Helicotylenchus and Pratylenchus, being the most important the root-knob nematode Meloidogyne spp.

  13. PLANT-PARASITIC NEMATODES ON STONE FRUITS AND CITRUS IN LEBANON

    Directory of Open Access Journals (Sweden)

    Said K. Ibrahim

    2016-06-01

    Full Text Available Ibrahim Said K., Ibrahim Azar, Christian Naser, Badran Akikki and Ludmilla Ibrahim. 2016. Plant-parasitic nematodes on stone fruits and citrus in Lebanon. Lebanese Science Journal, 17(1: 9-24. This study aimed to determine the occurrence, distribution of plant parasitic nematodes on stone fruits in Lebanon and to determine the effect of plant extracts on the mortality of several nematode species. A total of 308 soil samples were collected from five different crops. Almost all surveyed areas showed infection with nematodes. The soil infestation rate with nematodes in collected soil samples from all 10 surveyed crops ranged from 66.6 to 100%. Eighteen out of 308 soil samples were free of nematodes (5.8%. All the collected soil samples from nectarine and plum orchards were infested with nematodes (100%, followed by citrus (97.6%, apple (88.7%, pear and quince (85.7%, and cherry (81.4%. The lowest infection (66.6% was detected on almond and apricot. The level of infestation varied from one area to another and ranged between 0.1 and 28 nematodes per 1 g of soil, with the highest number obtained on cherry. Several genera were identified based on morphological characters including: root-knot nematodes (Meloidogyne spp., Tylenchulus, Xiphinema, Rotylenchus, Pratylenchus, and Longidorus. Tylenchulus and Radopholus spp. were the most common on citrus trees, whereas Pratylechus and Meloidogyne spp. were detected almost in all the samples collected from all the crops. Six chopped aromatic plants were tested in pot experiments to control nematodes population densities. The results revealed that carbofuran (nematicide was the most effective (88.48% in comparison to the plant materials. Allium sativum gave the highest control (76.52% followed by Tageta patula (72.0%, Cucurbita maxima (71.84% and Inula viscosa (63.96%. Origanum syriacum (55.04% and Thymus (53.72% were less effective in comparison to the rest of tested plant materials.

  14. Infectivity and reproduction of Meloidogyne incognita (Kofoid and ...

    African Journals Online (AJOL)

    Infectivity and reproduction of Meloidogyne incognita (Kofoid and White) Chitwood on African yam bean, Sphenostylis stenocarpa (Hochst Ex. A. Rich) Harms accessions as influenced by botanical soil amendments.

  15. Reação de porta-enxertos comerciais de tomateiro a Meloidogyne mayaguensis Reaction of commercial tomato rootstocks plant to Meloidogyne mayaguensis

    Directory of Open Access Journals (Sweden)

    Rafael Ricardo Cantu

    2009-09-01

    Full Text Available O objetivo do presente trabalho foi verificar a resistência ao nematóide Meloidogyne mayaguensis em oito porta-enxertos de tomateiro considerados resistentes à Meloidogyne incognita, M. javanica e M. arenaria, comercializados no Brasil. Os porta-enxertos testados foram: 'Guardião', 'Helper-M', 'Anchor-T', 'Dr. K', 'Kagemuscha', 'TMA 809', 'Magnet' e 'He-Man'. O experimento constou de 9 tratamentos (8 porta-enxertos e a cultivar Rutgers utilizada como padrão de suscetibilidade, com 6 repetições, sendo cada parcela constituída por 1 planta por vaso, mantidas em casa de vegetação. As plantas foram inoculadas com 5.000 ovos e eventuais juvenis infectantes de M. mayaguensis. O experimento seguiu o delineamento inteiramente casualizado. Aos 60 dias da inoculação procederam-se as avaliações, quando foram avaliados os índices de galhas e massas de ovos, número de nematóides no solo e na raiz, peso do sistema radicular e o fator de reprodução. Todos os porta-enxertos estudados demonstraram-se suscetíveis a M. mayaguensis.The objective of this research was to verify the resistance response of eight Brazilian commercial tomato rootstocks to the nematode Meloidogyne mayaguensis. The studied rootstocks were: 'Guardião', 'Helper-M', 'Anchor-T', 'Dr. K', 'Kagemuscha', 'TMA 809', 'Magnet' and 'He-Man'. The experiment consisted of 9 treatments (8 rootstocks and 'Rutgers' used as susceptible control, with 6 replication. Each plot was constituted by 1 plant per pot, maintained in green-house. The plants were inoculated with 5,000 eggs and second stage juvenile of M. mayaguensis. The experimental design was completely randomized. The evaluation was 60 days after inoculation, when the root weight, gall and egg mass index, nematode number in soil and in root and reproduction factor were evaluated. All studied rootstocks were susceptible to M. mayaguensis.

  16. Phytopathogenic Nematodes

    NARCIS (Netherlands)

    Helder, J.; Vervoort, M.T.W.; Megen, van H.H.B.; Rybarczyk-Mydlowska, K.; Quist, C.W.; Smant, G.; Bakker, J.

    2015-01-01

    Soil is teeming with life, and rhizosphere soil is even more densely in habited than bulk soil. In terms of biomass, bacteria and fungi are dominant groups, whereas nematodes (roundworms) are the most abundant Metazoans. Bulk soil, soil not directly affected by living plant roots, typically harbours

  17. Plant elicitor peptides promote plant defences against nematodes in soybean.

    Science.gov (United States)

    Lee, Min Woo; Huffaker, Alisa; Crippen, Devany; Robbins, Robert T; Goggin, Fiona L

    2018-04-01

    Plant elicitor peptides (Peps) are widely distributed among angiosperms, and have been shown to amplify immune responses in multiple plant families. Here, we characterize three Peps from soybean (Glycine max) and describe their effects on plant defences against two damaging agricultural pests, the root-knot nematode (Meloidogyne incognita) and the soybean cyst nematode (Heterodera glycines). Seed treatments with exogenous GmPep1, GmPep2 or GmPep3 significantly reduced the reproduction of both nematodes. Pep treatment also protected plants from the inhibitory effects of root-knot nematodes on above-ground growth, and up-regulated basal expression levels of nematode-responsive defence genes. GmPep1 induced the expression of its propeptide precursor (GmPROPEP1), a nucleotide-binding site leucine-rich repeat protein (NBS-LRR), a pectin methylesterase inhibitor (PMEI), Respiratory Burst Oxidase Protein D (RBOHD) and the accumulation of reactive oxygen species (ROS) in leaves. In addition, GmPep2 and GmPep3 seed treatments up-regulated RBOHD expression and ROS accumulation in roots and leaves. These results suggest that GmPeps activate plant defences through systemic transcriptional reprogramming and ROS signalling, and that Pep seed treatments represent a potential strategy for nematode management. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  18. Reproduction of Plant-parasitic Nematodes on Winter Rapeseed (Brassica napus ssp. oleiferas)

    OpenAIRE

    Bernard, E. C.; Montgomery-Dee, M. E.

    1993-01-01

    The reproduction of isolates of five plant-parasitic nematode species on the winter rapeseed cultivars Bridger, Gorzanski, H-47, Lindora, and Viking was evaluated. Each cultivar was a good host for Helicotylenchus pseudorobustus, Meloidogyne hapla, and M. incognita, All rapeseed cultivars were poor hosts for Pratylenchus scribneri, in comparison with a susceptible reference host. Heterodera glycines females rarely developed on any cultivar, but low numbers of juveniles invaded roots and males...

  19. Comparative efficacy of different approaches to managing Meloidogyne incognita on green bean

    Directory of Open Access Journals (Sweden)

    Ahmad S. Al-Hazmi

    2017-01-01

    Full Text Available A greenhouse study was conducted to compare the relative efficacy of different approaches to managing Meloidogyne incognita on green bean. These approaches included chemical (fumigant, non-fumigant, seed dressing, and seed dip, biological (the egg-parasitic fungus, Paecilomyces lilacinus and the mycorrhizal fungus Glomus sp., physical (soil solarization, and cultural (chicken litter and urea methods. Accordingly, nine different control materials and application methods plus nematode-infected and non-infected controls were compared. Two important parameters were considered: plant response (plant growth and root galling and nematode reproduction (production of eggs and the reproduction factor Rf. The results showed that the use of chicken litter as an organic fertilizer severely affected the growth and survival of the plants. Therefore, this treatment was removed from the evaluation test. All of the other eight treatments were found to be effective against nematode reproduction, but with different levels of efficacy. The eight treatments decreased (38.9–99.8% root galling, increased plant growth and suppressed nematode reproduction. Based on three important criteria, namely, gall index (GI, egg mass index (EMI, and nematode reproduction factor (RF, the tested materials and methods were categorized into three groups according to their relative control efficacy under the applied test conditions. The three groups were as follows: (1 the relatively high effective group (GI = 1.0–1.4, Rf = 0.07–0.01, which included the fumigant dazomet, the non-fumigant fenamiphos, soil solarization, and seed dip with fenamiphos; (2 the relatively moderate effective group (GI = 3.4–4.0, Rf = 0.24–0.60, which included seed dressing with fenamiphos and urea; and (3 the relatively less effective group (GI = 5.0, Rf = 32.2–37.2, which included P. lilacinus and Glomus sp.

  20. Effects of silicon on the penetration and reproduction events of Meloidogyne exigua on coffee roots

    Directory of Open Access Journals (Sweden)

    Rodrigo Vieira Silva

    2015-06-01

    Full Text Available Considering that the root-knot nematode Meloidogyne exigua has caused great yield losses to coffee production in Brazil, this study aimed to determine whether the penetration and the reproduction events of this nematode on the roots of plants from two coffee cultivars with different levels of basal resistance to this nematode could be affected by silicon (Si. Coffee plants from the cultivars Catuaí and IAPAR 59, which are susceptible and resistant, respectively, to M. exigua, were grown in pots containing Si-deficient soil that was amended with either calcium silicate (+Si or calcium carbonate (–Si. The Si concentration on the root tissue significantly increased by 159 and 97% for the +Si plants from the cultivars Catuaí and IAPAR 59, respectively, compared to the –Si plants of these cultivars. The population of M. exigua, the number of galls and the number of eggs were significantly reduced on the roots of the +Si plants of the cultivars Catuaí and IAPAR 59 compared to the –Si plants of these cultivars. It was concluded that the development and reproduction events of M. exigua were negatively impacted on the roots of coffee plants supplied with Si.

  1. Trigonella foenum-graecum (fenugreek-mediated suppression of Meloidogyne javanica in mungbean

    Directory of Open Access Journals (Sweden)

    Tayyaba Zia

    2013-12-01

    Full Text Available Soil amendments with powdered seeds of Trigonella foenum - graecum (fenugreek caused soil suppressiveness against Meloidogyne javanica. Decomposed seeds of fenugreek caused marked reduction in nematode population densities and subsequent root-knot development as compared to the aqueous extract of the seeds indicating that some indirect factors are involved in the suppression of root-knot nematode. Both decomposed seeds and aqueous extracts enhanced plant height and fresh weights of shoot whereas root growth remained uninfluenced. Changes in fungal communities associated with nematode control were studied by comparing population numbers of fungi in the soil and in internal root tissues (endorhiza in non-amended and fenugreekamended soils. Acremonium sp., Chaetomium globosum, Fusarium solani, Macrophomina phaseolina and Rhizoctonia solani were found to colonize inner root tissues of mungbean. Acremonium sp., C. globosum and F.solani were isolated in a relatively higher frequency from roots growing in the amended soils while M. phaseolina and R. solani colonized greatly in roots growing in non-amended soil. Of the fungi isolated from soils, Penicillium brefaldianum caused maximum juvenile mortality of M.javanica whereas F.solani caused greatest inhibition of egg hatch.

  2. Nematicidal activity of 2-thiophenecarboxaldehyde and methylisothiocyanate from caper (Capparis spinosa) against Meloidogyne incognita.

    Science.gov (United States)

    Caboni, Pierluigi; Sarais, Giorgia; Aissani, Nadhem; Tocco, Graziella; Sasanelli, Nicola; Liori, Barbara; Carta, Annarosa; Angioni, Alberto

    2012-08-01

    New pesticides based on plant extracts have recently gained interest in the development of nontoxic crop protection chemicals. Numerous research studies are focused on the isolation and identification of new active compounds derived from plants. In this manuscript we report about the use of the Mediterranean species Capparis spinosa as a potent natural nematicidal agent against the root knot nematodes Meloidogyne incognita. Leaves, stems, and caper buds of Capparis spinosa were used to obtain their methanol extracts (LME, SME, BME) that were successively in vitro tested against second stage nematode juveniles (J2). In terms of paralysis induction, the methanol extract of the stem part (SME) was found more effective against M. incognita and then the caper methanol buds and leaves extracts. The chemical composition analysis of the extracts carried out by GC/MS and LC/MS techniques showed that methylisothiocyanate was the main compound of SME. The EC50 for SME after 3 days of immersion was 215 ± 36 mg/L. The constituent components of SME such as 2-thiophenecarboxaldehyde and methylisothiocyanate were successively in vitro tested for their nematicidal activity against J2. Both compounds induced paralysis on root knot nematodes ranking first (EC50 = 7.9 ± 1.6, and 14.1 ± 1.9 mg/L respectively) for M. incognita. Moreover, 2-thiophenecarboxaldehyde showed a strong fumigant activity.

  3. Responses of Guava Plants to Inoculation with Arbuscular Mycorrhizal Fungi in Soil Infested with Meloidogyne enterolobii

    Science.gov (United States)

    Campos, Maryluce Albuquerque da Silva; da Silva, Fábio Sérgio Barbosa; Yano-Melo, Adriana Mayumi; de Melo, Natoniel Franklin; Pedrosa, Elvira Maria Régis; Maia, Leonor Costa

    2013-01-01

    In the Northeast of Brazil, expansion of guava crops has been impaired by Meloidogyne enterolobii that causes root galls, leaf fall and plant death. Considering the fact that arbuscular mycorrhizal Fungi (AMF) improve plant growth giving protection against damages by plant pathogens, this work was carried out to select AMF efficient to increase production of guava seedlings and their tolerance to M. enterolobii. Seedlings of guava were inoculated with 200 spores of Gigaspora albida, Glomus etunicatum or Acaulospora longula and 55 days later with 4,000 eggs of M. enterolobii. The interactions between the AMF and M. enterolobii were assessed by measuring leaf number, aerial dry biomass, CO2 evolution and arbuscular and total mycorrhizal colonization. In general, plant growth was improved by the treatments with A. longula or with G. albida. The presence of the nematode decreased arbuscular colonization and increased general enzymatic activity. Higher dehydrogenase activity occurred with the A. longula treatment and CO2 evolution was higher in the control with the nematode. More spores and higher production of glomalin-related soil proteins were observed in the treatment with G. albida. The numbers of galls, egg masses and eggs were reduced in the presence of A. longula. Inoculation with this fungus benefitted plant growth and decreased nematode reproduction. PMID:25288951

  4. Penetration, Post-penetration Development, and Reproduction of Meloidogyne incognita on Cucumis melo var. texanus.

    Science.gov (United States)

    Faske, T R

    2013-03-01

    Cucumis melo var. texanus, a wild melon commonly found in the southern United States and two accessions, Burleson Co. and MX 1230, expressed resistance to Meloidogyne incognita in preliminary experiments. To characterize the mechanism of resistance, we evaluated root penetration, post-penetration development, reproduction, and emigration of M. incognita on these two accessions of C. melo var. texanus. Additionally, we evaluated 22 accessions of C. melo var. texanus for their reaction against M. incognita in a greenhouse experiment. Fewer (P ≤ 0.05) J2 penetrated the root system of C. melo var. texanus accessions (Burleson Co. and MX 1230) and C. metuliferus (PI 482452) (resistant control), 7 days after inoculation (DAI) than in C. melo 'Hales Best Jumbo' (susceptible control). A delayed (P ≤ 0.05) rate of nematode development was observed at 7, 14, and 21 DAI that contributed to lower (P ≤ 0.05) egg production on both accessions and C. metuliferus compared with C. melo. Though J2 emigration was observed on all Cucumis genotypes a higher (P ≤ 0.05) rate of J2 emigration was observed from 3 to 6 DAI on accession Burleson Co. and C. metuliferus than on C. melo. The 22 accessions of C. melo var. texanus varied relative to their reaction to M. incognita with eight supporting similar levels of nematode reproduction to that of C. metuliferus. Cucumis melo var. texanus may be a useful source of resistance against root-knot nematode in melon.

  5. Weed Hosts of Meloidogyne arenaria and M. incognita Common in Tobacco Fields in South Carolina.

    Science.gov (United States)

    Tedford, E C; Fortnum, B A

    1988-10-01

    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 Rumex crispus, Amaranthus hybridus, Ambrosia artemisiifolia, lpomoea hederacea var. integriuscula, Setaria lutescens, Sida spinosa, Portulaca oleracea, and Rumex acetosella were moderate hosts. Taraxacum officinale, Ipomoea hederacea, Cyperus esculentus, Cynodon dactyIon, Echinochloa crus-galli, Eleusine indica, Sorghum halepense, Setaria viridis, Digitaria sanguinalis, and Datura stramonium were poor hosts for M. arenaria. Amaranthus palmeri, Amaranthus hybridus, Chenopodium album, Euphorbia maculata, Setaria lutescens, Vicia villosa, Sida spinosa, Rumex crispus, and Portulaca oleracea were moderate hosts and Ipomoea hederacea var. integriuscula, Xanthium strumarium, Cyperus esculentus, Cynodon dactylon, Paspalum notatum, Eleusine indica, Setaria viridis, and Rumex acetosella were poor hosts for M. incognita. None of the above were good hosts for M. incognita. Tobacco 'PD4' supported large numbers of both nematode species.

  6. Mangrove formulations for the management of meloidogyne javanica (treub) chitwood under field conditions

    International Nuclear Information System (INIS)

    Tariq, M.; Dawar, S.

    2015-01-01

    Six months field experiment were set up from June to November in Department of Botany, University of Karachi to investigate the influence of mangroves (Avicennia marina, Rhizophora mucronata) parts separately or combined parts for the control of Meloidogyne javanica (Treub.) Chitwood. Mangroves parts including leaves, stem, pneumatophore and combined parts were applied to field in form of powder at rate of 60 g/plot, capsules and pellets at 120 g/plot. Results pertaining to seed germination percentage, plant length, plant weight and yield showed outstanding improvement in both okra and mung bean when combined parts pellets of A. marina and R. mucronata were used. All parts of A. marina, R. mucronata pellets and powder were effective in controlling of M. javanica infection but maximum reduction in root knot nematode were obtained by the amendment of mangrove combined parts powder. (author)

  7. Agrobacteria Enhance Plant Defense Against Root-Knot Nematodes on Tomato.

    Science.gov (United States)

    Lamovšek, Janja; Stare, Barbara Gerič; Pleško, Irena Mavrič; Širca, Saša; Urek, Gregor

    2017-06-01

    The increased incidence of the crown gall disease caused by Agrobacterium tumefaciens has long been associated with activities of root-knot nematodes (Meloidogyne spp.). Pot experiments on tomato were designed to assess plant vitality, nematode reproduction, and crown gall incidence in combined infection with Agrobacterium and Meloidogyne spp. on tomato roots. Results suggest that tomato plants infected with pathogenic A. tumefaciens 2 days before the nematodes show enhanced plant defense against M. ethiopica resulting in lower egg and gall counts on roots 45 and 90 days postinoculation (dpi); no significantly enhanced defense was observed when the plant was inoculated with bacteria and nematodes at the same time. Split-root experiments also showed that the observed interaction was systemic. Reverse-transcription quantitative polymerase chain reaction analysis that targeted several genes under plant hormonal control suggests that the suppression was mediated via systemic acquired resistance by the pathogenesis-related protein 1 and that M. ethiopica did not enhance the defense reaction of tomato against Agrobacterium spp. Nematodes completely inhibited tumor growth in a 45-day experiment if inoculated onto the roots before the pathogenic bacteria. We conclude that the observed antagonism in the tested pathosystem was the result of initially strong plant defense that was later suppressed by the invading pathogen and pest.

  8. Msp40 effector of root-knot nematode manipulates plant immunity to facilitate parasitism.

    Science.gov (United States)

    Niu, Junhai; Liu, Pei; Liu, Qian; Chen, Changlong; Guo, Quanxin; Yin, Junmei; Yang, Guangsui; Jian, Heng

    2016-01-22

    Root-knot nematodes (RKNs) are obligate biotrophic parasites that invade plant roots and engage in prolonged and intimate relationships with their hosts. Nematode secretions, some of which have immunosuppressing activity, play essential roles in successful parasitism; however, their mechanisms of action remain largely unknown. Here, we show that the RKN-specific gene MiMsp40, cloned from Meloidogyne incognita, is expressed exclusively in subventral oesophageal gland cells and is strongly upregulated during early parasitic stages. Arabidopsis plants overexpressing MiMsp40 were more susceptible to nematode infection than were wild type plants. Conversely, the host-derived MiMsp40 RNAi suppressed nematode parasitism and/or reproduction. Moreover, overexpression of MiMsp40 in plants suppressed the deposition of callose and the expression of marker genes for bacterial elicitor elf18-triggered immunity. Transient expression of MiMsp40 prevented Bax-triggered defence-related programmed cell death. Co-agroinfiltration assays indicated that MiMsp40 also suppressed macroscopic cell death triggered by MAPK cascades or by the ETI cognate elicitors R3a/Avr3a. Together, these results demonstrate that MiMsp40 is a novel Meloidogyne-specific effector that is injected into plant cells by early parasitic stages of the nematode and that plays a role in suppressing PTI and/or ETI signals to facilitate RKN parasitism.

  9. Nematicidal activity of crambe extracts on Meloidogyne spp.

    Directory of Open Access Journals (Sweden)

    Sidiane Coltro-Roncato

    2016-08-01

    Full Text Available Alternative methods for the control of nematodes, such as the use of plant secondary metabolites, can be explored for integrated pest management systems. The objective of this work was to assess the best solvent for obtaining allyl isothiocyanate from Crambe abyssinica leaves, and the effects of this extract on Meloidogyne incognita and M. javanica. Dry leaves of C. abyssinica at 200 mg L-1 were used to prepare extracts by using water (by infusion and grinding, acetone, water + ethanol (hydroalcoholic extraction, methanol, hexane, and chloroform as solvents. Following the evaporation of the solvents, the residue was resuspended in water for use in the experiments. Distilled water and chemical nematicide were used as control treatments. Once the most effective extracts were defined, the following dosages of dried crambe leaves were used: 0, 200, 300, 400, and 500 mg L-1. High performance liquid chromatography (HPLC was used to quantify the allyl isothiocyanate present in the extracts. After the solvents evaporated, the residues were eluted with water and used in assays with 200 eggs for the hatching test or 200 second stage juveniles (J2 for mobility and mortality tests. The hydroalcoholic extract was the most effective in reducing the hatching of M. incognita and M. javanica juveniles, by 71.6 and 74.4 percentage points, respectively. The mortality of M. incognita and M. javanica in the hydroalcoholic extract was 93.2 and 64.4%, respectively, followed by the methanol extract (17.6 and 34% and the extract obtained by grinding (9.2 and 28%. The hydroalcoholic extract at 250 mg L-1 showed high nematicidal effect. The HPLC analysis of the extracts revealed that only the methanol and hydroalcoholic extracts had allyl isothiocyanate, indicating that the inhibitory effects on the hatching, mobility, and mortality were not solely attributed to the presence of this compound.

  10. Heterologous expression of taro cystatin protects transgenic tomato against Meloidogyne incognita infection by means of interfering sex determination and suppressing gall formation.

    Science.gov (United States)

    Chan, Yuan-Li; Yang, Ai-Hwa; Chen, Jen-Tzu; Yeh, Kai-Wun; Chan, Ming-Tsair

    2010-03-01

    Plant-parasitic nematodes are a major pest of many plant species and cause global economic loss. A phytocystatin gene, Colocasia esculenta cysteine proteinase inhibitor (CeCPI), isolated from a local taro Kaosiang No. 1, and driven by a CaMV35S promoter was delivered into CLN2468D, a heat-tolerant cultivar of tomato (Solanum lycopersicum). When infected with Meloidogyne incognita, one of root-knot nematode (RKN) species, transgenic T1 lines overexpressing CeCPI suppressed gall formation as evidenced by a pronounced reduction in gall numbers. In comparison with wild-type plants, a much lower proportion of female nematodes without growth retardation was observed in transgenic plants. A decrease of RKN egg mass in transgenic plants indicated seriously impaired fecundity. Overexpression of CeCPI in transgenic tomato has inhibitory functions not only in the early RKN infection stage but also in the production of offspring, which may result from intervention in sex determination.

  11. Organic and Inorganic Nitrogen Amendments to Soil as Nematode Suppressants

    Science.gov (United States)

    Rodríguez-Kábana, R.

    1986-01-01

    Inorganic fertilizers containing ammoniacal nitrogen or formulations releasing this form of N in the soil are most effective for suppressing nematode populations. Anhydrous ammonia has been shown to reduce soil populations of Tylenchorhynchus claytoni, Helicotylenchus dihystera, and Heterodera glycines. The rates required to obtain significant suppression of nematode populations are generally in excess of 150 kg N/ha. Urea also suppresses several nematode species, including Meloidogyne spp., when applied at rates above 300 kg N/ha. Additional available carbon must be provided with urea to permit soil microorganisms to metabolize excess N and avoid phytotoxic effects. There is a direct relation between the amount of "protein" N in organic amendments and their effectiveness as nematode population suppressants. Most nematicidal amendments are oil cakes, or animal excrements containing 2-7% (w:w) N; these materials are effective at rates of 4-10 t/ha. Organic soil amendments containing mucopolysaccharides (e.g., mycelial wastes, chitinous matter) are also effective nematode suppressants. PMID:19294153

  12. Direct identification of the Meloidogyne incognita secretome reveals proteins with host cell reprogramming potential.

    Directory of Open Access Journals (Sweden)

    Stéphane Bellafiore

    2008-10-01

    Full Text Available The root knot nematode, Meloidogyne incognita, is an obligate parasite that causes significant damage to a broad range of host plants. Infection is associated with secretion of proteins surrounded by proliferating cells. Many parasites are known to secrete effectors that interfere with plant innate immunity, enabling infection to occur; they can also release pathogen-associated molecular patterns (PAMPs, e.g., flagellin that trigger basal immunity through the nematode stylet into the plant cell. This leads to suppression of innate immunity and reprogramming of plant cells to form a feeding structure containing multinucleate giant cells. Effectors have generally been discovered using genetics or bioinformatics, but M. incognita is non-sexual and its genome sequence has not yet been reported. To partially overcome these limitations, we have used mass spectrometry to directly identify 486 proteins secreted by M. incognita. These proteins contain at least segmental sequence identity to those found in our 3 reference databases (published nematode proteins; unpublished M. incognita ESTs; published plant proteins. Several secreted proteins are homologous to plant proteins, which they may mimic, and they contain domains that suggest known effector functions (e.g., regulating the plant cell cycle or growth. Others have regulatory domains that could reprogram cells. Using in situ hybridization we observed that most secreted proteins were produced by the subventral glands, but we found that phasmids also secreted proteins. We annotated the functions of the secreted proteins and classified them according to roles they may play in the development of root knot disease. Our results show that parasite secretomes can be partially characterized without cognate genomic DNA sequence. We observed that the M. incognita secretome overlaps the reported secretome of mammalian parasitic nematodes (e.g., Brugia malayi, suggesting a common parasitic behavior and a possible

  13. Integrative taxonomy of root-knot nematodes reveals multiple independent origins of mitotic parthenogenesis.

    Directory of Open Access Journals (Sweden)

    Toon Janssen

    Full Text Available During sampling of several Coffea arabica plantations in Tanzania severe root galling, caused by a root-knot nematode was observed. From pure cultures, morphology and morphometrics of juveniles and females matched perfectly with Meloidogyne africana, whereas morphology of the males matched identically with those of Meloidogyne decalineata. Based on their Cox1 sequence, however, the recovered juveniles, females and males were confirmed to belong to the same species, creating a taxonomic conundrum. Adding further to this puzzle, re-examination of M. oteifae type material showed insufficient morphological evidence to maintain its status as a separate species. Consequently, M. decalineata and M. oteifae are synonymized with M. africana, which is herewith redescribed based on results of light and scanning electron microscopy, ribosomal and mitochondrial DNA sequences, isozyme electrophoresis, along with bionomic and cytogenetic features. Multi-gene phylogenetic analysis placed M. africana outside of the three major clades, together with M. coffeicola, M. ichinohei and M. camelliae. This phylogenetic position was confirmed by several morphological features, including cellular structure of the spermatheca, egg mass position, perineal pattern and head shape. Moreover, M. africana was found to be a polyphagous species, demonstrating that "early-branching" Meloidogyne spp. are not as oligophagous as had previously been assumed. Cytogenetic information indicates M. africana (2n = 21 and M. ardenensis (2n = 51-54 to be a triploid mitotic parthenogenetic species, revealing at least four independent origins of mitotic parthenogenesis within the genus Meloidogyne. Furthermore, M. mali (n = 12 was found to reproduce by amphimixis, indicating that amphimictic species with a limited number of chromosomes are widespread in the genus, potentially reflecting the ancestral state of the genus. The wide variation in chromosome numbers and associated changes in

  14. HOW FUNGI INTERACT WITH NEMATODE TO ACTIVATE THE PLANT DEFENCE RESPONSE TO TOMATO PLANTS.

    Science.gov (United States)

    Leonetti, P; Costanza, A; Zonno, M C; Molinari, S; Altomare, C

    2014-01-01

    Management of plant parasitic nematodes with nematode predators, parasites or antagonists is an eco-friendly approach that may avoid the problems arisen by the use of toxic chemicals. Fungi belonging to Trichoderma spp. are well known in literature for their role in control of plant parasitic nematodes. Root-knot nematodes (RKNs), Meloidogyne spp., are obligate parasites that cause the formation of familiar galls on the roots of many cultivated plants. The interaction between the M. incognita motile second stage juveniles (J2s) and the isolate ITEM 908 of Trichoderma harzianum was examined in its effect on the nematode infestation level of susceptible tomato plants. To gain insight into the mechanisms by which ITEM 908 interacts with nematode-infected tomato plants, the expression patterns of the genes PR1 (marker of Salycilic Acid-depending resistance signalling pathway) and JERF3 (marker of the Jasmonic Acid/Ethylene-depending resistance signalling pathway) were detected over time in: i) untreated roots; ii) roots pre-treated with the fungus; iii) roots inoculated with the nematode; iv) pre-treated and inoculated roots. Infestation parameters were checked in untreated plants and plants treated with the fungus to test the effect of the fungus on nematode infestation level and to compare this effect with the expression of the genes PR1 and JERF3, involved in induced resistance.

  15. Interaction between root-knot nematodes and Solanum spp. : variation in pathogenicity, cytology, proteins and DNA = [De interactie tussen wortelknobbelnematoden en Solanum spp. : variatie in ziekteverwekkend vermogen, cytologie, eiwitten en DNA

    NARCIS (Netherlands)

    Beek, van der J.G.

    1997-01-01


    This thesis describes genetic variation in the root-knot nematodes Meloidogyne hapla, M. chitwoodi and M. fallax, particularly with respect to their pathogenicity on Solanum spp. Significant differences in virulence and

  16. The neem Azadirachta indica as a means to control soil nematodes and its application in vegetable cultures in Benin

    Directory of Open Access Journals (Sweden)

    Colin, JE.

    1992-01-01

    Full Text Available The use of neem extracts for pest control is less common in nematology than in entomology. The purpose of this paper is to make a short review of the agronomical potential of the neem tree, with particular emphasis on its role for the control of deleterious nematodes. A specifie case for the control of Meloidogyne, which was carried out in Benin, is presented.

  17. Microbiomes associated with infective stages of root-knot and lesion nematodes in soil.

    Directory of Open Access Journals (Sweden)

    Ahmed Elhady

    Full Text Available Endoparasitic root-knot (Meloidogyne spp. and lesion (Pratylenchus spp. nematodes cause considerable damage in agriculture. Before they invade roots to complete their life cycle, soil microbes can attach to their cuticle or surface coat and antagonize the nematode directly or by induction of host plant defenses. We investigated whether the nematode-associated microbiome in soil differs between infective stages of Meloidogyne incognita and Pratylenchus penetrans, and whether it is affected by variation in the composition of microbial communities among soils. Nematodes were incubated in suspensions of five organically and two integrated horticultural production soils, recovered by sieving and analyzed for attached bacteria and fungi after washing off loosely adhering microbes. Significant effects of the soil type and nematode species on nematode-associated fungi and bacteria were revealed as analyzed by community profiling using denaturing gradient gel electrophoresis. Attached microbes represented a small specific subset of the soil microbiome. Two organic soils had very similar bacterial and fungal community profiles, but one of them was strongly suppressive towards root-knot nematodes. They were selected for deep amplicon sequencing of bacterial 16S rRNA genes and fungal ITS. Significant differences among the microbiomes associated with the two species in both soils suggested specific surface epitopes. Among the 28 detected bacterial classes, Betaproteobacteria, Bacilli and Actinobacteria were the most abundant. The most frequently detected fungal genera were Malassezia, Aspergillus and Cladosporium. Attached microbiomes did not statistically differ between these two soils. However, Malassezia globosa and four fungal species of the family Plectosphaerellaceae, and the bacterium Neorhizobium galegae were strongly enriched on M. incognita in the suppressive soil. In conclusion, the highly specific attachment of microbes to infective stages of

  18. Optimum Concentrations of Trichoderma longibrachiatum and Cadusafos for Controlling Meloidogyne javanica on Zucchini Plants.

    Science.gov (United States)

    Sokhandani, Zahra; Moosavi, Mohammad Reza; Basirnia, Tahereh

    2016-03-01

    A factorial experiment was established in a completely randomized design to verify the effect of different inoculum levels of an Iranian isolate of Trichoderma longibrachiatum separately and in combination with various concentrations of cadusafos against Meloidogyne javanica in the greenhouse. Zucchini seeds were soaked for 12 hr in five densities (0, 10(5), 10(6), 10(7), and 10(8) spores/ml suspension) of the fungus prior to planting in pots containing four concentrations of cadusafos (0, 0.5, 1, and 2 mg a.i./kg soil). The data were analyzed using a custom response surface regression model and the response surface curve and contour plots were drawn. Reliability of the model was examined by comparing the result of new experimental treatments with the predicted results. The optimal levels of these two variables also were calculated. The interactive effects of concentrations of Trichoderma and cadusafos were insignificant for several responses such as the total number of eggs per gram soil, the number of intact eggs per gram soil, nematode reproduction factor, and control percent. Closeness of experimental mean values with the expected values proved the validity of the model. The optimal levels of the cadusafos concentration and Trichoderma concentration that caused the best plant growth and lowest nematode reproduction were 1.7 mg a.i./kg soil and 10(8) conidia/ml suspension, respectively.

  19. Dose assessment of HeberNem to control of Meloidogyne incognita Chitwood in greenhouses

    Directory of Open Access Journals (Sweden)

    Mario Fleitas Díaz

    2016-02-01

    Full Text Available In the houses of protected crops Agricultural Company República Dominicana, Carlos Manuel de Céspedes municipality, Camagüey, an experiment was developed to evaluate different doses of bionematicide HeberNem in controlling the nematode Meloidogyne incognita Chitwood and his participation in the growth and development of the tomato (Solanum lycopersicum crop, the experimental design was in randomized blocks, the test was composed of 8 treatments replicated twice, evaluating a total of 40 plants for each treatment which were measured: plant height, stem diameter the number of leaflets, the number of clusters per plant, number of flowers per cluster and number of fruits per bunch, they were made weekly. Also at the end of the campaign took root degree determined according to the scale indicated by Zeck, (1971. Data were analyzed using analysis of variance and determined the levels of statistical significance at 5%, by dócima Tukey multiple range. We found an inverse relationship between the parameters of growth and development weighed against the presence of M. incognita Chitwood. At doses of 8 l / ha, 12 l / ha and 16 l / ha were achieved better results in controlling the nematode M. incognita Chitwood.

  20. Chemical Composition and Nematicidal Activity of Essential Oil of Agastache rugosa against Meloidogyne incognita

    Directory of Open Access Journals (Sweden)

    Zhi Wei Deng

    2013-04-01

    Full Text Available The aim of this research was to determine the chemical composition and nematicidal activity of essential oil of Agastache rugosa flowering aerial parts against the root knot nematode, Meloidogyne incognita, and to isolate and identify any nematicidal constituents from the essential oil. The essential oil of A. rugosa aerial parts was obtained by hydrodistillation and analyzed by GC-FID and GC-MS. A total of 37 components of the essential oil were identified, with the principal compounds being methyleugenol (50.51%, estragole (8.55%, and eugenol (7.54%, followed by thymol (3.62%, pulegone (2.56%, limonene (2.49% and caryophyllene (2.38%. Based on bioactivity-guided fractionation, the three active constituents were isolated from the essential oil and identified as methyleugenol, estragole and eugenol. The essential oil of A. rugosa exhibited strong nematicidal activity against M. incognita, with a LC50 value of 47.3 μg/mL. The components eugenol (LC50 = 66.6 μg/mL and methyleugenol (LC50 = 89.4 μg/mL exhibited stronger nematicidal activity against M. incognita (LC50 = 185.9 μg/mL. The results indicate that the essential oil of A. rugosa aerial parts and its constituent compounds have potential for development into natural nematicides for control of the root knot nematode.

  1. Gene expression analysis in Musa acuminata during compatible interactions with Meloidogyne incognita.

    Science.gov (United States)

    Castañeda, Nancy Eunice Niño; Alves, Gabriel Sergio Costa; Almeida, Rosane Mansan; Amorim, Edson Perito; Fortes Ferreira, Claudia; Togawa, Roberto Coiti; Costa, Marcos Mota Do Carmo; Grynberg, Priscila; Santos, Jansen Rodrigo Pereira; Cares, Juvenil Enrique; Miller, Robert Neil Gerard

    2017-03-01

    Endoparasitic root-knot nematodes (RKNs) ( Meloidogyne spp.) cause considerable losses in banana ( Musa spp.), with Meloidogyne incognita a predominant species in Cavendish sub-group bananas. This study investigates the root transcriptome in Musa acuminata genotypes 4297-06 (AA) and Cavendish Grande Naine (CAV; AAA) during early compatible interactions with M. incognita . Roots were analysed by brightfield light microscopy over a 35 d period to examine nematode penetration and morphological cell transformation. RNA samples were extracted 3, 7 and 10 days after inoculation (DAI) with nematode J2 juveniles, and cDNA libraries were sequenced using lllumina HiSeq technology. Sequences were mapped to the M. acuminata ssp. malaccensis var. Pahang genome sequence, differentially expressed genes (DEGs) identified and transcript representation determined by gene set enrichment and pathway mapping. Microscopic analysis revealed a life cycle of M. incognita completing in 24 d in CAV and 27 d in 4279-06. Comparable numbers of DEGs were up- and downregulated in each genotype, with potential involvement of many in early host defence responses involving reactive oxygen species and jasmonate/ethylene signalling. DEGs revealed concomitant auxin metabolism and cell wall modification processes likely to be involved in giant cell formation. Notable transcripts related to host defence included those coding for leucine-rich repeat receptor-like serine/threonine-protein kinases, peroxidases, thaumatin-like pathogenesis-related proteins, and DREB, ERF, MYB, NAC and WRKY transcription factors. Transcripts related to giant cell development included indole acetic acid-amido synthetase GH3.8 genes, involved in auxin metabolism, as well as genes encoding expansins and hydrolases, involved in cell wall modification. Expression analysis in M. acuminata during compatible interactions with RKNs provides insights into genes modulated during infection and giant cell formation. Increased

  2. Effect of plant and fungous metabolites on Meloidogyne exigua Efeito de metabólitos vegetais e fúngicos sobre Meloidogyne exigua

    Directory of Open Access Journals (Sweden)

    Daniel Rufino Amaral

    2009-01-01

    Full Text Available As nematodes cause great damage to Brazilian coffee production, effective methods to control these parasites are necessary. In a previous work Allium cepa L., Cajanus cajan (L. Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam. Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. and Coffea arabica L. produced active substances against Meloidogyne exigua Goeldi, a nematode widely disseminated through Brazilian coffee fields. Thus, aqueous extracts of such plants, collected in a different season from that of the previous work, as well as crude metabolites produced in liquid medium by Fusarium moniliforme Shelden and Cylindrocarpon magnusianum (Sacc. Woll., were submitted to in vitro assays with M. exigua second-stage juveniles (J2. All plants and fungi produced active substances against J2. Therefore, their metabolites were applied to six-month-old coffee plants inoculated with M. exigua. After 90 days in a greenhouse, those samples obtained from A. cepa, L. leucocephala, R. graveolens and F. moniliforme inhibited the production of galls and eggs by M. exigua, demonstrating potential to control such parasite.Os nematóides acarretam grandes perdas aos produtores brasileiros de café, sendo necessário o desenvolvimento de métodos eficientes para o seu controle. Em trabalho anterior, Allium cepa L., Cajanus cajan (L. Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam. Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. e Coffea arabica L. produziram substâncias ativas contra o nematóide Meloidogyne exigua Goeldi, que é amplamente disseminado pelos cafezais brasileiros. Dando continuidade a esse trabalho, extratos aquosos das plantas mencionadas, coletadas em época diferente daquela

  3. Identification, Validation and Utilization of Novel Nematode-Responsive Root-Specific Promoters in Arabidopsis for Inducing Host-Delivered RNAi Mediated Root-Knot Nematode Resistance

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    Atul Kakrana

    2017-12-01

    Full Text Available The root-knot nematode (RKN, Meloidogyne incognita, is an obligate, sedentary endoparasite that infects a large number of crops and severely affects productivity. The commonly used nematode control strategies have their own limitations. Of late, RNA interference (RNAi has become a popular approach for the development of nematode resistance in plants. Transgenic crops capable of expressing dsRNAs, specifically in roots for disrupting the parasitic process, offer an effective and efficient means of producing resistant crops. We identified nematode-responsive and root-specific (NRRS promoters by using microarray data from the public domain and known conserved cis-elements. A set of 51 NRRS genes was identified which was narrowed down further on the basis of presence of cis-elements combined with minimal expression in the absence of nematode infection. The comparative analysis of promoters from the enriched NRRS set, along with earlier reported nematode-responsive genes, led to the identification of specific cis-elements. The promoters of two candidate genes were used to generate transgenic plants harboring promoter GUS constructs and tested in planta against nematodes. Both promoters showed preferential expression upon nematode infection, exclusively in the root in one and galls in the other. One of these NRRS promoters was used to drive the expression of splicing factor, a nematode-specific gene, for generating host-delivered RNAi-mediated nematode-resistant plants. Transgenic lines expressing dsRNA of splicing factor under the NRRS promoter exhibited upto a 32% reduction in number of galls compared to control plants.

  4. 215 - 222_Tijjani_Nematodes

    African Journals Online (AJOL)

    pc

    ABSTRACT. Field and screen house studies were conducte. (IITA) Research Farms, Minjibir, Kano State. Savannah Agro-ecological Zone, North breeding lines to infestation of Meloidogyne s. 5000 eggs of Meloidogyne spp. The experim. Complete Block Design laid out in the fiel. Randomized Design. In each location ...

  5. Reação de crisântemos a Meloidogyne incognita, Meloidogyne javanica e Meloidogyne enterolobii

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    Lucivane Aparecida Gonçalves

    2014-03-01

    Full Text Available Este trabalho teve como objetivo avaliar a resistência de 14 variedades de crisântemos aos nematoides Meloidogyne incognita, M. javanica e M. enterolobii. O experimento foi conduzido em delineamento inteiramente casualizado, constando de 15 tratamentos e 4 repetições, por espécie de nematoide. Cada parcela foi constituída por uma planta por vaso, mantidas em casa de vegetação e inoculadas com 5.000 ovos e eventuais juvenis de M. incognita, M. javanica e M. enterolobii. Após 60 dias, os índices de massas de ovos, número de nematoides por grama de raiz e o fator de reprodução foram avaliados. As variedades apresentaram imunidade a M. incognita, M. javanica e M. enterolobii, exceto 'Capello Vermelho' e 'White Reagon', que foram respectivamente suscetível e resistente a M. incognita.

  6. EVALUATION OF THE REACTION OF WATERMELON PARENT AND F1 PLANTS TO Meloidogyne enterolobii

    Directory of Open Access Journals (Sweden)

    LÉIA SANTOS DAMACENO

    2016-01-01

    Full Text Available The aim of this study was to evaluate the performance of progenies from Citrullus lanatus var. lanatus (cultivated watermelons when crossed with progenies from C. lanatus var. citroides (fodder watermelon with a historic of resistance to the nematode Meloidogyne enterolobii. The parents and their F1s were evaluated for resistance to this nematode. In the initial stages of eleven treatments, watermelon seedlings plantlets were transplanted to plastic bags of six kilograms once the first leaves developed. Ten inoculated plants with 5,200 eggs in the soil near the stem of the plant and four non-inoculated ones were used in each treatment, in a complete block design. Sixty-two days after sowing, the following characteristics were evaluated: the length of the aerial part of the plant (LAP, in m, fresh mass of the aerial part (FMAP, in g, root fresh mass (RFM, in g, egg number (EN and reproduction factor (RF. A comparison between the averages of inoculated and non-inoculated plants was performed using Scott-Knott test at 5% and the diallelic analysis was performed using the GENES program. The morphological characteristics did not allow for the identification of the parent plants or the F1s with respect to nematode resistance, but the variables EN and RF were useful for such identification. The analyses of the general and specific combining abilities indicate highly significant effects with respect to this resistance, showing additive gene effects as well as dominance and epistatic gene effects, allowing for identification of parents and F1s that can be used in watermelon breeding programs to improve resistance to the M. enterolobii.

  7. Enzyme phenotypes of Meloidogyne spp. populations

    OpenAIRE

    Carneiro, R.M.D.G.; Almeida, M.R.A.; Quénéhervé, Patrick

    2000-01-01

    Les phénotypes enzymatiques de l'estérase (EST), la malate déshydrogènase (MDH), la superoxide dismutase (SOD) et la glutamate-oxaloacétate transaminase (GOT) ont été utilisés de manière systématique afin de caractériser plusieurs espèces de #Meloidogyne$ provenant principalement du Brésil et de quelques pays des régions américaines. C'est l'activité estérastique qui a présenté le plus grand polymorphisme et s'est montrée la plus utile dans la caractérisation des espèces. A l'aide de cette en...

  8. Exposure to double-stranded RNA mediated by tobacco rattle virus leads to transcription up-regulation of effector gene Mi-vap-2 from Meloidogyne incognita and promotion of pathogenicity in progeny.

    Science.gov (United States)

    Chi, Yuankai; Wang, Xuan; Le, Xiuhu; Ju, Yuliang; Guan, Tinglong; Li, Hongmei

    2016-02-01

    Meloidogyne spp. are economically important plant parasites and cause enormous damage to agriculture world-wide. These nematodes use secreted effectors which modify host cells, allowing them to obtain the nutrients required for growth and development. A better understanding of the roles of effectors in nematode parasitism is critical for understanding the mechanisms of nematode-host interactions. In this study, Mi-vap-2 of Meloidogyne incognita, a gene encoding a venom allergen-like protein, was targeted by RNA interference mediated by the tobacco rattle virus. Unexpectedly, compared with a wild type line, a substantial up-regulation of Mi-vap-2 transcript was observed in juveniles collected at 7 days p.i. from Nicotiana benthamiana agroinfiltrated with TRV::vap-2. This up-regulation of the targeted transcript did not impact development of females or the production of galls, nor the number of females on the TRV::vap-2 line. In a positive control line, the transcript of Mi16D10 was knocked down in juveniles from the TRV::16D10 line at 7 days p.i., resulting in a significant inhibition of nematode development. The up-regulation of Mi-vap-2 triggered by TRV-RNAi was inherited by the progeny of the nematodes exposed to double-stranded RNA. Meanwhile, a substantial increase in Mi-VAP-2 expression in those juvenile progeny was revealed by ELISA. This caused an increase in the number of galls (71.2%) and females (84.6%) produced on seedlings of N. benthamiana compared with the numbers produced by control nematodes. Up-regulation of Mi-vap-2 and its encoded protein therefore enhanced pathogenicity of the nematodes, suggesting that Mi-vap-2 may be required for successful parasitism during the early parasitic stage of M. incognita. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  9. A novel Meloidogyne enterolobii effector MeTCTP promotes parasitism by suppressing programmed cell death in host plants.

    Science.gov (United States)

    Zhuo, Kan; Chen, Jiansong; Lin, Borong; Wang, Jing; Sun, Fengxia; Hu, Lili; Liao, Jinling

    2017-01-01

    Meloidogyne enterolobii is one of the most important plant-parasitic nematodes that can overcome the Mi-1 resistance gene and damage many economically important crops. Translationally controlled tumour protein (TCTP) is a multifunctional protein that exists in various eukaryotes and plays an important role in parasitism. In this study, a novel M. enterolobii TCTP effector, named MeTCTP, was identified and functionally characterized. MeTCTP was specifically expressed within the dorsal gland and was up-regulated during M. enterolobii parasitism. Transient expression of MeTCTP in protoplasts from tomato roots showed that MeTCTP was localized in the cytoplasm of the host cells. Transgenic Arabidopsis thaliana plants overexpressing MeTCTP were more susceptible to M. enterolobii infection than wild-type plants in a dose-dependent manner. By contrast, in planta RNA interference (RNAi) targeting MeTCTP suppressed the expression of MeTCTP in infecting nematodes and attenuated their parasitism. Furthermore, MeTCTP could suppress programmed cell death triggered by the pro-apoptotic protein BAX. These results demonstrate that MeTCTP is a novel plant-parasitic nematode effector that promotes parasitism, probably by suppressing programmed cell death in host plants. © 2016 BSPP and John Wiley & Sons Ltd.

  10. Absorption of 32P-phosphate and photosynthetic 14CO2 fixation in mulberry attacked by the root-knot nematoda, Meloidogyne mali

    International Nuclear Information System (INIS)

    Toida, Yukio; Yamashita, Tadaaki

    1985-01-01

    Radioactive phosphate was applied to mulberry plants infected with the root-knot nematode, Meloidogyne mali, to analyze root uptake and translocation into leaves. A much larger accumulation of 32 P was observed in the roots and leaves on the upper part of the stem in the infected plant than in the uninfected one. The photosynthetic activity measured by the short-term 14 CO 2 fixation by a leaf segment in the leaf of the infected plant was half that of the uninfected plant. However, no significant differences in the percentage distribution of 14 C in various photosynthetic products were recognized, and main 14 C compounds consist of alanine of serine in the leaves of both plant. It was suggested that the low growth performance and dwarfing in the mulberry plant attacked by the nematode were caused by the remarkable increase of phosphate uptake under the limited supply of photosynthetic products. (author)

  11. Biological control of Meloidogyne incognita by Trichoderma ...

    African Journals Online (AJOL)

    Similar tests were carried out on inoculated plants treated with such ISR elicitors to search for possible enzyme activity changes as a result of resistance induction. Nematode infection did not cause any significant changes in GLUC activity, whilst PPO activity was enhanced in inoculated with respect to uninoculated roots.

  12. Nematode suppression and growth stimulation in corn plants (Zea mays L.) irrigated with domestic effluent.

    Science.gov (United States)

    Barros, Kenia Kelly; do Nascimento, Clístenes Williams Araújo; Florencio, Lourdinha

    2012-01-01

    Treated wastewater has great potential for agricultural use due to its concentrations of nutrients and organic matter, which are capable of improving soil characteristics. Additionally, effluents can induce suppression of plant diseases caused by soil pathogens. This study evaluates the effect of irrigation with effluent in a UASB reactor on maize (Zea mays L.) development and on suppression of the diseases caused by nematodes of the genus Meloidogyne. Twelve lysimeters of 1 m(3) each were arranged in a completely randomized design, with four treatments and three replicates. The following treatments were used: T1 (W+I), irrigation with water and infestation with nematodes; T2 (W+I+NPK), irrigation with water, infestation with nematodes and fertilization with nitrogen (N), phosphorus (P) and potassium (K); T3 (E+I), irrigation with effluent and infestation with nematodes; and T4 (E+I+P), irrigation with effluent, infestation with nematodes and fertilization with phosphorus. The plants irrigated with the effluent plus the phosphorus fertilizer had better growth and productivity and were more resistant to the disease symptoms caused by the nematodes. The suppression levels may have been due to the higher levels of Zn and NO(3)(-) found in the leaf tissue of the plants irrigated with the effluent and phosphorus fertilizer.

  13. PLANT-PARASITIC NEMATODES ON STONE FRUITS AND CITRUS IN LEBANON

    International Nuclear Information System (INIS)

    Ibrahim, S.K.; Azar, I.; Naser, CH.; Akikki, B; Ibrahim, L.

    2016-01-01

    This study aimed to determine the occurrence, distribution of plant parasitic nematodes on stone fruits in Lebanon and to determine the effect of plant extracts on the mortality of several nematode species. A total of 308 soil samples were collected from five different crops. Almost all surveyed areas showed infection with nematodes.The soil infestation rate with nematodes in collected soil samples from all 10 surveyed crops ranged from 66.6 to 100%. Eighteen out of 308 soil samples were free of nematodes (5.8%). All the collected soil samples from nectarine and plum orchards were infested with nematodes (100%), followed by citrus (97.6%), apple (88.7%), pear and quince (85.7%), and cherry (81.4%). The lowest infection (66.6%) was detected on almond and apricot. The level of infestation varied from one area to another and ranged between 0.1and 28 nematodes per 1 g of soil, with the highest number obtained on cherry. Several genera were identified based on morphological characters including:root-knot nematodes (Meloidogynespp.), Tylenchulus, Xiphinema, Rotylenchus, Pratylenchus, and Longidorus. Tylenchulus and Radopholus spp. were the most common on citrus trees, whereas Pratylechus and Meloidogyne spp. were detected almost in all the samples collected from all the crops. Six chopped aromatic plants were tested in pot experiments to control nematodes population densities. The results revealed that carbofuran (nematicide) was the most effective (88.48%) in comparison to the plant materials. Allium sativum gave the highest control (76.52%) followed by Tageta patula (72.0%), Cucurbita maxima (71.84%) and Inula viscosa (63.96%). Origanum syriacum (55.04%)d Thymus (53.72%) were less effective in comparison to the rest of tested plant materials. (author)

  14. The effects of Brassica green manures on plant parasitic and free living nematodes used in combination with reduced rates of synthetic nematicides.

    Science.gov (United States)

    Riga, Ekaterini

    2011-06-01

    Brassica plants once incorporated into soil as green manures have recently been shown to have biofumigant properties and have the potential of controlling plant-parasitic nematodes. In Washington State, plant-parasitic nematodes are successfully managed with synthetic nematicides. However, some of the synthetic nematicides became unavailable recently or their supply is limited leaving growers with few choices to control plant-parasitic nematodes. The objective of this project was to evaluate the effects of Brassica green manures on their own and in combination with reduced rates of synthetic nematicides on plant-parasitic nematodes and free living nematodes. In a greenhouse experiment and field trials in three seasons, Brassica green manures in combination with half the recommended rate of 1,3-dichloropropene (1,3-D, Telone) reduced root knot nematode, Meloidogyne chitwoodi to below detection levels, and reduced lesion nematodes, Pratylenchus penetrans and stubby root nematodes, Paratrichodorus allius, to below economic thresholds. The combination treatments did not affect the beneficial free-living nematode populations and the non-pathogenic Pseudomonas. The total cost of growing and soil-incorporating Brassica crops as green manures in combination with reduced rates of 1,3-D was approximately 35% lower than the present commercial costs for application for the full rate of this fumigant. Integrating conventional management practices with novel techniques fosters sustainability of production systems and can increase economic benefit to producers while reducing chemical input.

  15. Expression of Phenylalanine Ammonia Lyase Genes in Maize Lines Differing in Susceptibility to Meloidogyne incognita.

    Science.gov (United States)

    Starr, J L; Yang, W; Yan, Y; Crutcher, F; Kolomiets, M

    2014-12-01

    Maize is a well-known host for Meloidogyne incognita, and there is substantial variation in host status among maize genotypes. In previous work it was observed that nematode reproduction increased in the moderately susceptible maize inbred line B73 when the ZmLOX3 gene from oxylipid metabolism was knocked out. Additionally, in this mutant line, use of a nonspecific primer for phenyl alanine ammonialyase (PAL) genes indicated that expression of these genes was reduced in the mutant maize plants whereas expression of several other defense related genes was increased. In this study, we used more specific gene primers to examine the expression of six PAL genes in three maize genotypes that were good, moderate, and poor hosts for M. incognita, respectively. Of the six PAL genes interrogated, two (ZmPAL3 and ZmPAL6) were not expressed in either M. incognita-infected or noninfected roots. Three genes (ZmPAL1, ZmPAL2, and ZmPAL5) were strongly expressed in all three maize lines, in both nematode-infected and noninfected roots, between 2 and 16 d after inoculation (DAI). In contrast, ZmPAL4 was most strongly expressed in the most-resistant maize line W438, was not detected in the most-susceptible maize line CML, and was detected only at 8 DAI in the maize line B73 that supported intermediate levels of reproduction by M. incognita. These observations are consistent with at least one PAL gene playing a role in modulating host status of maize toward M. incognita and suggest a need for additional research to further elucidate this association.

  16. Pathogenicity of Two Populations of Meloidogyne hapla Chitwood on Alfalfa and Sainfoin.

    Science.gov (United States)

    Wofford, D S; Gray, F A; Eckert, J W

    1989-01-01

    The pathogenicity of two populations of the northern root-knot nematode, Meloidogyne hapla Chitwood, population 1 (P1) from alfalfa and population 2 (P2) from sainfoin, was studied on both alfalfa and sainfoin for 25 weeks. Alfalfa and sainfoin plants inoculated with P2 had significantly (P nematode populations present in the intended area of cultivar use and to design screening procedures to account for population pathogenicity variability.

  17. Hydrogen Cyanide Produced by Pseudomonas chlororaphis O6 Exhibits Nematicidal Activity against Meloidogyne hapla

    Directory of Open Access Journals (Sweden)

    Beom Ryong Kang

    2018-02-01

    Full Text Available Root-knot nematodes (Meloidogyne spp. are parasites that attack many field crops and orchard trees, and affect both the quantity and quality of the products. A root-colonizing bacterium, Pseudomonas chlororaphis O6, possesses beneficial traits including strong nematicidal activity. To determine the molecular mechanisms involved in the nematicidal activity of P. chlororaphis O6, we constructed two mutants; one lacking hydrogen cyanide production, and a second lacking an insecticidal toxin, FitD. Root drenching with wild-type P. chlororaphis O6 cells caused juvenile mortality in vitro and in planta. Efficacy was not altered in the fitD mutant compared to the wild-type but was reduced in both bioassays for the mutant lacking hydrogen cyanide production. The reduced number of galls on tomato plants caused by the wild-type strain was comparable to that of a standard chemical nematicide. These findings suggest that hydrogen cyanide-producing root colonizers, such as P. chlororaphis O6, could be formulated as “green” nematicides that are compatible with many crops and offer agricultural sustainability.

  18. Mentha x piperita, Mentha spicata and Effects of Their Essential Oils on Meloidogyne in Soil

    Science.gov (United States)

    Walker, J. T.; Melin, J. B.

    1996-01-01

    Six peppermint (Mentha x piperita) and six spearmint (M. spicata) PI accessions were inoculated with Meloidogyne incognita race 3 and M. arenaria race 2, under greenhouse conditions. No galls formed on roots of any of the plants inoculated with 1,800 eggs/pot. Fewer than two galls per root system formed on three PI accessions of peppermint inoculated with M. incognita at 5,400 eggs/pot. Only one peppermint accession developed galls when inoculated with M. arenaria, whereas none of the spearmint accessions was susceptible to this species. Plant dry weights generally were unaffected by infection with root-knot nematodes at these densities. Growing peppermint and spearmint accessions for 8 or 12 weeks in M. arenaria-infested soil before tomato resulted in 90% reduction of root galls compared with tomato following tomato. Cineole, eugenol, geraniol, linalool, and peppermint oils at 50 and 250 mg oil/kg soil caused no reduction in the number of galls caused by M. arenaria on tomato. At 1,500 mg oil/kg soil, geraniol, eugenol, linalool, and peppermint oils (P =0.05) reduced the number of galls caused by M. arenaria, but the decrease in galling caused by M. incognita was not significant. Geraniol, linalool, and peppermint oil at 1,000 and 1,500 mg were phytotoxic to tomato. PMID:19277186

  19. Control potential of Meloidogyne javanica and Ditylenchus spp. using fluorescent Pseudomonas and Bacillus spp.

    Directory of Open Access Journals (Sweden)

    Marcielly F. Turatto

    Full Text Available ABSTRACT Plant Growth Promoting Rhizobacteria (PGPR have different mechanisms of action in the development of plants, such as growth promotion, production of phytohormones and antibiotic substances and changes in root exudates. These help to control plant diseases. In order to evaluate the potential of microorganisms in the control of Meloidogyne javanica and Ditylenchus spp., five rhizobacteria isolated from rhizosphere of garlic cultivated in the Curitibanos (SC region were tested. Hatching chambers were set on Petri dishes, in which were added 10 mL of bacterial suspension and 1 mL of M. javanica eggs suspension, at the rate of 4500, on the filter paper of each chamber. The same procedure was performed with 300 juvenile Ditylenchus spp. The experimental design was completely randomized, with four replications. The evaluations were performed every 72 h for nine days. The antagonized population of nematodes was determined in Peters counting chamber, determining the percentage hatching (for M. javanica and motility (for Ditylenchus spp. Isolates CBSAL02 and CBSAL05 significantly reduced the hatching of M. javanica eggs (74% and 54.77%, respectively and the motility of Ditylenchus spp. (55.19% and 53.53%, respectively in vitro. Isolates were identified as belonging to the genera Pseudomonas (CBSAL05 and Bacillus (CBSAL02.

  20. INFLUENCE OF ROOTSTOCKS ON Fusarium WILT, NEMATODE INFESTATION, YIELD AND FRUIT QUALITY IN WATERMELON PRODUCTION

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    Juan Carlos Álvarez-Hernández

    2015-08-01

    Full Text Available Cucurbita maxima x Cucurbita moschata rootstock are used to prevent infection with Fusarium oxysporum f. sp. niveum in watermelon production; however, this rootstock is not effective against nematode attack. Because of their vigor, the grafted plants can be planted at lower plant densities than the non-grafted plants. The tolerance to Fusarium oxysporum f. sp. niveum and Meloidogyne incognita was assessed in watermelon plants grafted onto a hybrid of Citrullus lanatus cv Robusta or the Cucurbita maxima x Cucurbita moschata cv Super Shintoza rootstocks. The densities of plants were 2083 and 4166 plants ha-1. Non-grafted watermelons were the controls. The Crunchy Red and Sangría watermelon cultivars were used as the scions, it the latter as a pollinator. The experiments were performed for two production cycles in soils infested with Fusarium oxysporum f. sp. niveum and Meloidogyne incognita. The incidence of Fusarium oxysporum f. sp. niveum was significantly greater in the non-grafted than in the grafted plants. The grafted plants presented similar resistance to Fusarium regardless of the rootstock. The root-knot galling index for Meloidogyne incognita was significantly lower in plants grafted onto Citrullus lanatus cv Robusta than onto the other rootstock. The yields of plants grafted onto Citrullus lanatus cv Robusta grown at both plant densities were significantly higher than in the other treatments.

  1. Evaluation of methyl bromide alternatives efficacy against soil-borne pathogens, nematodes and soil microbial community.

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    Hongwei Xie

    Full Text Available Methyl bromide (MB and other alternatives were evaluated for suppression of Fusarium spp., Phytophthora spp., and Meloidogyne spp. and their influence on soil microbial communities. Both Fusarium spp. and Phytophthora spp. were significantly reduced by the MB (30.74 mg kg-1, methyl iodide (MI: 45.58 mg kg-1, metham sodium (MS: 53.92 mg kg-1 treatments. MS exhibited comparable effectiveness to MB in controlling Meloidogyne spp. and total nematodes, followed by MI at the tested rate. By contrast, sulfuryl fluoride (SF: 33.04 mg kg-1 and chloroform (CF: 23.68 mg kg-1 showed low efficacy in controlling Fusarium spp., Phytophthora spp., and Meloidogyne spp. MB, MI and MS significantly lowered the abundance of different microbial populations and microbial biomass in soil, whereas SF and CF had limited influence on them compared with the control. Diversity indices in Biolog studies decreased in response to fumigation, but no significant difference was found among treatments in PLFA studies. Principal component and cluster analyses of Biolog and PLFA data sets revealed that MB and MI treatments greatly influenced the soil microbial community functional and structural diversity compared with SF treatment. These results suggest that fumigants with high effectiveness in suppressing soil-borne disease could significantly influence soil microbial community.

  2. Water transport through tomato roots infected with Meloidogyne incognita.

    NARCIS (Netherlands)

    Dorhout, R.; Gommers, F.J.; Kollöffel, C.

    1991-01-01


    The effect of Meloidogyne incognita on water flow in tomato roots was investigated in rooted split-stem cuttings. Total water flow through infected root parts was significantly lower than through comparable uninfected parts. Total water uptake was correlated with total length of the root

  3. Reação de linhagens de feijão-vagem ao Meloidogyne javanica e M. paranaensis em casa-de-vegetação = Reaction of snap bean to Meloidogyne javanica and M. paranaensis in greenhouse.

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    Fernando César Baida

    2011-04-01

    Full Text Available Nematoides formadores de galhas (Meloidogyne sp. são responsáveis pela baixa produtividade na cultura do feijoeiro, cujas perdas, provocadas por esses patógenos, podem chegar até 90%. O presente estudo teve como objetivo avaliar o comportamento de seis linhagens de feijoeiro (‘Hav 06’, ‘Hav 11’, ‘Hav 28’, ‘Hav 50’, ‘Hav 69’ e ‘Torino’ frente ao parasitismo de M. javanica e de M. paranaensis. As linhagens foram inoculadas com 5.000 ovos e eventuais juvenis dos respectivos nematoides. O delineamento experimental foi inteiramente casualizado, com dez repetições para cada tratamento com os nematoides e dez repetições para testemunha sem inoculação. Quarenta e cinco dias após inoculação, os sistemas radiculares foram coletados, lavados e avaliados quanto à produção de ovos e estimativa do Fator de Reprodução (FR. Os resultados mostraram baixa reprodução dos nematoides nas linhagens de feijão-vagem avaliadas, e que, para M. javanica, o FR variou de 0,02 a 0,05, enquanto que, para M. paranaensis, a variação foi de 0,04 a 0,36, indicando que todas as linhagens se comportaram como resistentes, apresentando FR Root-knot nematodes (Meloidogyne sp. are responsable for low productivity on bean culture, where the losses caused by this pathogen can reach 90%. The present study aimed to evaluate the behavior of six bean lineages (‘Hav 06’, ‘Hav 11’, ‘Hav 28’, ‘Hav 50’,‘Hav 69’ and ‘Torino’ against the parasitism of M. javanica and M. paranaensis. The lineages were inoculated with 5,000 eggs and possible juveniles of each nematode in a completely randomized design, with 10 replications per treatment with the nematodes and 10replications per treatment without inoculation (control. Forty-five days after inoculation, the roots systems were collected, washed and evaluated for egg production and estimated reproduction factor (RF. The results showed that, for M. javanica, the RF varied from 0.02to

  4. Characterization of Soil Suppressiveness to Root-Knot Nematodes in Organic Horticulture in Plastic Greenhouse.

    Science.gov (United States)

    Giné, Ariadna; Carrasquilla, Marc; Martínez-Alonso, Maira; Gaju, Núria; Sorribas, Francisco J

    2016-01-01

    The fluctuation of Meloidogyne population density and the percentage of fungal egg parasitism were determined from July 2011 to July 2013 in two commercial organic vegetable production sites (M10.23 and M10.55) in plastic greenhouses, located in northeastern Spain, in order to know the level of soil suppressiveness. Fungal parasites were identified by molecular methods. In parallel, pot tests characterized the level of soil suppressiveness and the fungal species growing from the eggs. In addition, the egg parasitic ability of 10 fungal isolates per site was also assessed. The genetic profiles of fungal and bacterial populations from M10.23 and M10.55 soils were obtained by Denaturing Gradient Gel Electrophoresis (DGGE), and compared with a non-suppressive soil (M10.33). In M10.23, Meloidogyne population in soil decreased progressively throughout the rotation zucchini, tomato, and radish or spinach. The percentage of egg parasitism was 54.7% in zucchini crop, the only one in which eggs were detected. Pochonia chlamydosporia was the only fungal species isolated. In M10.55, nematode densities peaked at the end of the spring-summer crops (tomato, zucchini, and cucumber), but disease severity was lower than expected (0.2-6.3). The percentage of fungal egg parasitism ranged from 3 to 84.5% in these crops. The results in pot tests confirmed the suppressiveness of the M10.23 and M10.55 soils against Meloidogyne. The number of eggs per plant and the reproduction factor of the population were reduced (P < 0.05) in both non-sterilized soils compared to the sterilized ones after one nematode generation. P. chlamydosporia was the only fungus isolated from Meloidogyne eggs. In in vitro tests, P. chlamydosporia isolates were able to parasitize Meloidogyne eggs from 50 to 97% irrespective of the site. DGGE fingerprints revealed a high diversity in the microbial populations analyzed. Furthermore, both bacterial and fungal genetic patterns differentiated suppressive from non

  5. The Nematode Caenorhabditis Elegans.

    Science.gov (United States)

    Kenyon, Cynthia

    1988-01-01

    Discusses advantages of nematode use for studying patterns of cell division, differentiation, and morphogenesis. Describes nematode development. Cites experimental approaches available for genetic studies. Reviews the topics of control of cell division and differentiation, the nervous system, and muscle assembly and function of the organism. (RT)

  6. Nematode-Trapping Fungi.

    Science.gov (United States)

    Jiang, Xiangzhi; Xiang, Meichun; Liu, Xingzhong

    2017-01-01

    Nematode-trapping fungi are a unique and intriguing group of carnivorous microorganisms that can trap and digest nematodes by means of specialized trapping structures. They can develop diverse trapping devices, such as adhesive hyphae, adhesive knobs, adhesive networks, constricting rings, and nonconstricting rings. Nematode-trapping fungi have been found in all regions of the world, from the tropics to Antarctica, from terrestrial to aquatic ecosystems. They play an important ecological role in regulating nematode dynamics in soil. Molecular phylogenetic studies have shown that the majority of nematode-trapping fungi belong to a monophyletic group in the order Orbiliales (Ascomycota). Nematode-trapping fungi serve as an excellent model system for understanding fungal evolution and interaction between fungi and nematodes. With the development of molecular techniques and genome sequencing, their evolutionary origins and divergence, and the mechanisms underlying fungus-nematode interactions have been well studied. In recent decades, an increasing concern about the environmental hazards of using chemical nematicides has led to the application of these biological control agents as a rapidly developing component of crop protection.

  7. Single basal application of thiacloprid for the integrated management of Meloidogyne incognita and Bemisia tabaci in tomato crops

    Science.gov (United States)

    Dong, Sa; Ren, Xiaofen; Zhang, Dianli; Ji, Xiaoxue; Wang, Kaiyun; Qiao, Kang

    2017-01-01

    Tomato growers commonly face heavy nematode (Meloidogyne incognita) and whitefly (B-biotype Bemisia tabaci) infestations, and previous studies demonstrated that thiacloprid could be used to control M. incognita and B. tabaci in cucumber. However, the efficacy of a single basal application of thiacloprid to control both pests and its effect on yield in tomato remains unknown. In this study, the potential of thiacloprid application to the soil for the integrated control of M. incognita and B. tabaci in tomato was evaluated in the laboratory and the field. Laboratory tests showed that thiacloprid was highly toxic to whitefly adults and eggs with an average lethal concentration 50 (LC50) of 14.7 and 62.2 mg ai L-1, respectively, and the LC50 of thiacloprid for nematode J2s and eggs averaged 36.2 and 70.4 mg ai L-1, respectively. In field trials, when thiacloprid was applied to the soil at 7.5, 15 and 30 kg ha-1 in two consecutive years, whitefly adults decreased by 37.8-75.4% within 60 days of treatment, and the root-galling index was reduced by 31.8-85.2%. Optimum tomato plant growth and maximum yields were observed in the 15 kg ha-1 treatment. The results indicated that a single basal application of thiacloprid could control M. incognita and B. tabaci and enhance tomato growth and yield.

  8. Application of Arbuscular Mycorrhizal Fungi during the Acclimatization of Alpinia purpurata to Induce Tolerance to Meloidogyne arenaria

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    Maryluce Albuquerque da Silva Campos

    2017-06-01

    Full Text Available An experiment was conducted to evaluate the tolerance of micropropagated and mycorrhized alpinia plants to the parasite Meloidogyne arenaria. The experimental design was completely randomized with a factorial arrangement of four inoculation treatments with arbuscular mycorrhizal fungi (AMF (Gigaspora albida, Claroideoglomus etunicatum, Acaulospora longula, and a non-inoculated control in the presence or absence of M. arenaria with five replicates. The following characteristics were evaluated after 270 days of mycorrhization and 170 days of M. arenaria inoculation: height, number of leaves and tillers, fresh mass of aerial and subterranean parts, dry mass of aerial parts, foliar area, nutritional content, mycorrhizal colonization, AMF sporulation, and the number of galls, egg masses, and eggs. The results indicated a significant interaction between the treatments for AMF spore density, total mycorrhizal colonization, and nutrient content (Zn, Na, and N, while the remaining parameters were influenced by either AMF or nematodes. Plants inoculated with A. longula or C. etunicatum exhibited greater growth than the control. Lower N content was observed in plants inoculated with AMF, while Zn and Na were found in larger quantities in plants inoculated with C. etunicatum. Fewer galls were observed on mycorrhized plants, and egg mass production and the number of eggs were lower in plants inoculated with G. albida. Plants inoculated with A. longula showed a higher percentage of total mycorrhizal colonization in the presence of the nematode. Therefore, the association of micropropagated alpinia plants and A. longula enhanced tolerance to parasitism by M. arenaria.

  9. Impact of castor meal on root-knot and free-living nematodes

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    Cecilia Helena Silvino Prata Ritzinger

    2014-08-01

    Full Text Available Soil amendment may enhance soil quality as well as reduce plant-parasitic nematode. Despite the many applications already undertaken using castor meal, its efficiency in controlling root-knot nematodes (RKN, Meloidogyne incognita when applied to melon (Cucumis melo is still not clear. Three different amounts of castor meal (Ricinus communis applied were evaluated in microplots planted with melon either with or without RKN. The impact of castor meal on soil free-living nematode communities was also determined. Total nematode genera richness was estimated as 37 for the entire set of microplots sampled across both sampling dates. Rarefaction analysis resulted in 12 collector's curves out of the total of 30 that reached the horizontal asymptote. Univariate ANOVA with two factors yielded differences (p < 0.05 only with regard to the time factor. Simpson, Shannon, Evenness and Equitability indices showed a trend toward moderate increases by the end of the experiment, while the other indices were higher for tomato in pre-transplant sampling compared to harvest. Nematode community and diversity changed during the course of the experiment, although there was substantial confounding heterogeneity within and between the factorial combinations from the beginning. Root knot population was not reduced by the castor meal but increased throughout the period, regardless of treatment. RKN reduced melon yield, number and weight of melon.

  10. Exploring the host parasitism of the migratory plant-parasitic nematode Ditylenchus destuctor by expressed sequence tags analysis.

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    Huan Peng

    Full Text Available The potato rot nematode, Ditylenchus destructor, is a very destructive nematode pest on many agriculturally important crops worldwide, but the molecular characterization of its parasitism of plant has been limited. The effectors involved in nematode parasitism of plant for several sedentary endo-parasitic nematodes such as Heterodera glycines, Globodera rostochiensis and Meloidogyne incognita have been identified and extensively studied over the past two decades. Ditylenchus destructor, as a migratory plant parasitic nematode, has different feeding behavior, life cycle and host response. Comparing the transcriptome and parasitome among different types of plant-parasitic nematodes is the way to understand more fully the parasitic mechanism of plant nematodes. We undertook the approach of sequencing expressed sequence tags (ESTs derived from a mixed stage cDNA library of D. destructor. This is the first study of D. destructor ESTs. A total of 9800 ESTs were grouped into 5008 clusters including 3606 singletons and 1402 multi-member contigs, representing a catalog of D. destructor genes. Implementing a bioinformatics' workflow, we found 1391 clusters have no match in the available gene database; 31 clusters only have similarities to genes identified from D. africanus, the most closely related species to D. destructor; 1991 clusters were annotated using Gene Ontology (GO; 1550 clusters were assigned enzyme commission (EC numbers; and 1211 clusters were mapped to 181 KEGG biochemical pathways. 22 ESTs had similarities to reported nematode effectors. Interestedly, most of the effectors identified in this study are involved in host cell wall degradation or modification, such as 1,4-beta-glucanse, 1,3-beta-glucanse, pectate lyase, chitinases and expansin, or host defense suppression such as calreticulin, annexin and venom allergen-like protein. This result implies that the migratory plant-parasitic nematode D. destructor secrets similar effectors to

  11. COMBINING EFFECTS OF CULTURAL PRACTICES AND RESISTANT CULTIVARS ON REDUCING THE INCIDENCE OF Meloidogyne spp. AND Thrips palmy Karny ON POTATO

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    Wiwin Setiawati

    2013-05-01

    Full Text Available Root-knot nematode (Meloidogyne spp. and melon thrips (Thrips palmy Karny are two serious pests on potato. These pests are conventionally controlled with synthetic pesticides. Cultural practices based on integrated pest management (IPM are alternative methods to control these pests. The study aimed to determine the effectiveness of combined applications of cultural practices and potato cultivars in reducing the incidences of nematode and thrips. Treatments evaluated were methods of nematode and thrips control by implementing IPM and conventional practices. A split-plot randomized complete block design with four replications was  sed. The main plots were IPM or cultural practices (subsoiling, soil solarization and use of trap crop of marigold Tagetes erecta and conventional practices using synthetic pesticides. The subplots were five potato cultivars, i.e. No. 095 (Herta x FLS–17, 720050/Kikondo, 676068/ I.1085, Granola, and Atlantic. The results showed that applications of cultural practices in combination with potato cultivars reduced Meloidogyne spp. population and potato tuber damage by 53.70% and 61.36%, respectively, as well as a significantly decreased thrips population. In the cultural control plots, thrips populations were below the action threshold (10.0 nymphs per leaf, therefore no single application of pesticide was used. This was in contrast to the conventional control treatments where insecticide was spayed 10 times until harvest. The subsoiling and solarization cut off the life cycle of the thrips and any survive thrips were trapped by marigold plant. Population of T. palmi on the five potato cultivars differed significantly; the lowest population was found on the cultivars No. 095 (Herta x FLS-17 and 676068/I.1085. The cultural control practices combined with potato cultivar No. 095 (Herta x FLS–17 were the best treatment for controlling Meloidogyne spp. and T. palmi on potato and also produced the highest yield (31.01 t

  12. Exploitation of FTA cartridges for the sampling, long-term storage, and DNA-based analyses of plant-parasitic nematodes.

    Science.gov (United States)

    Marek, Martin; Zouhar, Miloslav; Douda, Ondřej; Maňasová, Marie; Ryšánek, Pavel

    2014-03-01

    The use of DNA-based analyses in molecular plant nematology research has dramatically increased over recent decades. Therefore, the development and adaptation of simple, robust, and cost-effective DNA purification procedures are required to address these contemporary challenges. The solid-phase-based approach developed by Flinders Technology Associates (FTA) has been shown to be a powerful technology for the preparation of DNA from different biological materials, including blood, saliva, plant tissues, and various human and plant microbial pathogens. In this work, we demonstrate, for the first time, that this FTA-based technology is a valuable, low-cost, and time-saving approach for the sampling, long-term archiving, and molecular analysis of plant-parasitic nematodes. Despite the complex structure and anatomical organization of the multicellular bodies of nematodes, we report the successful and reliable DNA-based analysis of nematode high-copy and low-copy genes using the FTA technology. This was achieved by applying nematodes to the FTA cards either in the form of a suspension of individuals, as intact or pestle-crushed nematodes, or by the direct mechanical printing of nematode-infested plant tissues. We further demonstrate that the FTA method is also suitable for the so-called "one-nematode-assay", in which the target DNA is typically analyzed from a single individual nematode. More surprisingly, a time-course experiment showed that nematode DNA can be detected specifically in the FTA-captured samples many years after initial sampling occurs. Collectively, our data clearly demonstrate the applicability and the robustness of this FTA-based approach for molecular research and diagnostics concerning phytonematodes; this research includes economically important species such as the stem nematode (Ditylenchus dipsaci), the sugar beet nematode (Heterodera schachtii), and the Northern root-knot nematode (Meloidogyne hapla).

  13. Root-lesion nematodes suppress cabbage aphid population development by reducing aphid daily reproduction

    Directory of Open Access Journals (Sweden)

    W. H. Gera eHol

    2016-02-01

    Full Text Available Empirical studies have shown that belowground feeding herbivores can affect the performance of aboveground herbivores in different ways. Often the critical life-history parameters underlying the observed performance effects remain unexplored. In order to better understand the cause for the observed effects on aboveground herbivores, these ecological mechanisms must be better understood. In this study we combined empirical experiments with a modelling approach to analyse the effect of two root feeding endoparasitic nematodes with different feeding strategies on the population growth of the aboveground feeding specialist aphid Brevicoryne brassicae on Brassica nigra. The aim was to test whether emerging differences in life history characteristics (days until reproduction, daily reproduction would be sufficient to explain observed differences in aphid population development on plants with and without two species of nematodes. Aphid numbers were lower on plants with Pratylenchus penetrans in comparison to aphid numbers on plants with Meloidogyne spp. A dedicated experiment showed that aphid daily reproduction was lower on plants with P. penetrans (3.08 offspring per female per day in comparison to both uninfested plants and plants with Meloidogyne spp. (3.50 offspring per female per day. The species-specific reduction of aphid reproduction appeared independent of changes in amino acids, soluble sugars or the glucosinolate sinigrin in the phloem. An individual-based model revealed that relatively small differences in reproduction rate per female were sufficient to yield a similar difference in aphid populations as was found in the empirical experiments.

  14. Mi-1-Mediated Nematode Resistance in Tomatoes is Broken by Short-Term Heat Stress but Recovers Over Time.

    Science.gov (United States)

    Marques de Carvalho, Luciana; Benda, Nicole D; Vaughan, Martha M; Cabrera, Ana R; Hung, Kaddie; Cox, Thomas; Abdo, Zaid; Allen, L Hartwell; Teal, Peter E A

    2015-06-01

    Tomato (Solanum lycopersicum L.) is among the most valuable agricultural products, but Meloidogyne spp. (root-knot nematode) infestations result in serious crop losses. In tomato, resistance to root-knot nematodes is controlled by the gene Mi-1, but heat stress interferes with Mi-1-associated resistance. Inconsistent results in published field and greenhouse experiments led us to test the effect of short-term midday heat stress on tomato susceptibility to Meloidogyne incognita race 1. Under controlled day/night temperatures of 25°C/21°C, 'Amelia', which was verified as possessing the Mi-1 gene, was deemed resistant (4.1 ± 0.4 galls/plant) and Rutgers, which does not possess the Mi-1 gene, was susceptible (132 ± 9.9 galls/plant) to M. incognita infection. Exposure to a single 3 hr heat spike of 35°C was sufficient to increase the susceptibility of 'Amelia' but did not affect Rutgers. Despite this change in resistance, Mi-1 gene expression was not affected by heat treatment, or nematode infection. The heat-induced breakdown of Mi-1 resistance in 'Amelia' did recover with time regardless of additional heat exposures and M. incognita infection. These findings would aid in the development of management strategies to protect the tomato crop at times of heightened M. incognita susceptibility.

  15. Crosses prior to parthenogenesis explain the current genetic diversity of tropical plant-parasitic Meloidogyne species (Nematoda: Tylenchida).

    Science.gov (United States)

    Fargette, Mireille; Berthier, Karine; Richaud, Myriam; Lollier, Virginie; Franck, Pierre; Hernandez, Adan; Frutos, Roger

    2010-08-01

    The tropical and subtropical parthenogenetic plant-parasitic nematodes Meloidogyne are polyphagous major agricultural pests. Implementing proper pest management approaches requires a good understanding of mechanisms, population structure, evolutionary patterns and species identification. A comparative analysis of the mitochondrial vs nuclear diversity was conducted on a selected set of Meloidogyne lines from various geographic origins. Mitochondrial co2-16S sequences and AFLP markers of total DNA were applied because of their ability to evidence discrete genetic variation between closely related isolates. Several distinct maternal lineages were present, now associated with different genetic backgrounds. Relative discordances were found when comparing mitochondrial and nuclear diversity patterns. These patterns are most likely related to crosses within one ancestral genetic pool, followed by the establishment of parthenogenesis. In this case, they mirror the genetic backgrounds of the original individuals. Another aspect could be that species emergence was recent or on process from this original genetic pool and that the relatively short time elapsed since then and before parthenogenesis settlement did not allow for lineage sorting. This could also be compatible with the hypothesis of hybrids between closely related species. This genetic pool would correspond to a species as defined by the species interbreeding concept, but also including the grey area of species boundaries. This complex process has implications on the way genotypic and phenotypic diversity should be addressed. The phenotype of parthenogenetic lines is at least for part determined by the ancestral amphimictic genetic background. A direct consequence is, therefore, in terms of risk management, the limited confidence one can have on the direct association of an agronomic threat to a simple typing or species delineation. Risk management strategies and tools must thus consider this complexity when

  16. Analysis of the Transcriptome of the Infective Stage of the Beet Cyst Nematode, H. schachtii.

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    John Fosu-Nyarko

    Full Text Available The beet cyst nematode, Heterodera schachtii, is a major root pest that significantly impacts the yield of sugar beet, brassicas and related species. There has been limited molecular characterisation of this important plant pathogen: to identify target genes for its control the transcriptome of the pre-parasitic J2 stage of H. schachtii was sequenced using Roche GS FLX. Ninety seven percent of reads (i.e., 387,668 with an average PHRED score > 22 were assembled with CAP3 and CLC Genomics Workbench into 37,345 and 47,263 contigs, respectively. The transcripts were annotated by comparing with gene and genomic sequences of other nematodes and annotated proteins on public databases. The annotated transcripts were much more similar to sequences of Heterodera glycines than to those of Globodera pallida and root knot nematodes (Meloidogyne spp.. Analysis of these transcripts showed that a subset of 2,918 transcripts was common to free-living and plant parasitic nematodes suggesting that this subset is involved in general nematode metabolism and development. A set of 148 contigs and 183 singletons encoding putative homologues of effectors previously characterised for plant parasitic nematodes were also identified: these are known to be important for parasitism of host plants during migration through tissues or feeding from cells or are thought to be involved in evasion or modulation of host defences. In addition, the presence of sequences from a nematode virus is suggested. The sequencing and annotation of this transcriptome significantly adds to the genetic data available for H. schachtii, and identifies genes primed to undertake required roles in the critical pre-parasitic and early post-parasitic J2 stages. These data provide new information for identifying potential gene targets for future protection of susceptible crops against H. schachtii.

  17. Analysis of the Transcriptome of the Infective Stage of the Beet Cyst Nematode, H. schachtii.

    Science.gov (United States)

    Fosu-Nyarko, John; Nicol, Paul; Naz, Fareeha; Gill, Reetinder; Jones, Michael G K

    2016-01-01

    The beet cyst nematode, Heterodera schachtii, is a major root pest that significantly impacts the yield of sugar beet, brassicas and related species. There has been limited molecular characterisation of this important plant pathogen: to identify target genes for its control the transcriptome of the pre-parasitic J2 stage of H. schachtii was sequenced using Roche GS FLX. Ninety seven percent of reads (i.e., 387,668) with an average PHRED score > 22 were assembled with CAP3 and CLC Genomics Workbench into 37,345 and 47,263 contigs, respectively. The transcripts were annotated by comparing with gene and genomic sequences of other nematodes and annotated proteins on public databases. The annotated transcripts were much more similar to sequences of Heterodera glycines than to those of Globodera pallida and root knot nematodes (Meloidogyne spp.). Analysis of these transcripts showed that a subset of 2,918 transcripts was common to free-living and plant parasitic nematodes suggesting that this subset is involved in general nematode metabolism and development. A set of 148 contigs and 183 singletons encoding putative homologues of effectors previously characterised for plant parasitic nematodes were also identified: these are known to be important for parasitism of host plants during migration through tissues or feeding from cells or are thought to be involved in evasion or modulation of host defences. In addition, the presence of sequences from a nematode virus is suggested. The sequencing and annotation of this transcriptome significantly adds to the genetic data available for H. schachtii, and identifies genes primed to undertake required roles in the critical pre-parasitic and early post-parasitic J2 stages. These data provide new information for identifying potential gene targets for future protection of susceptible crops against H. schachtii.

  18. Molecular Cloning and Characterization of a Wild Eggplant Solanum aculeatissimum NBS-LRR Gene, Involved in Plant Resistance to Meloidogyne incognita

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    Xiaohui Zhou

    2018-02-01

    Full Text Available Root-knot nematodes, Meloidogyne spp., cause considerable damage in eggplant production. Transferring of resistance genes from wild relatives would be valuable for the continued improvement of eggplant. Solanum aculeatissimum, a wild relative of eggplant possessing resistance to Meloidogyne incognita, is potentially useful for genetically enhancing eggplant. In the present study, we have isolated and characterized a nucleotide-binding site leucine-rich repeat (NBS-LRR resistance gene, designated as SacMi. The full-length cDNA of the SacMi gene was obtained using the technique of rapid-amplification of cDNA ends (RACE. The open reading frame of the SacMi gene was 4014 bp and encoded a protein of 1338 amino acids. Sequence analysis indicated that SacMi belong to the non- Toll/Interleukin-1 receptor (TIR-NBS-LRR type disease-resistance genes. Interestingly, quantitative RT-PCR showed that SacMi is expressed at low levels in uninfected roots, but was up-regulated by infection with M. incognita. To investigate the role of SacMi in S. aculeatissimum resistance against M. incognica, the tobacco rattle virus (TRV-mediated virus-induced gene silencing (VIGS system was used. Silencing of SacMi enhanced susceptibility of S. aculeatissimum plants to M. incognita, suggesting the possible involvement of SacMi in resistance against M. incognita infection.

  19. Molecular Cloning and Characterization of a Wild Eggplant Solanum aculeatissimum NBS-LRR Gene, Involved in Plant Resistance to Meloidogyne incognita.

    Science.gov (United States)

    Zhou, Xiaohui; Liu, Jun; Bao, Shengyou; Yang, Yan; Zhuang, Yong

    2018-02-15

    Root-knot nematodes, Meloidogyne spp., cause considerable damage in eggplant production. Transferring of resistance genes from wild relatives would be valuable for the continued improvement of eggplant. Solanum aculeatissimum , a wild relative of eggplant possessing resistance to Meloidogyne incognita , is potentially useful for genetically enhancing eggplant. In the present study, we have isolated and characterized a nucleotide-binding site leucine-rich repeat (NBS-LRR) resistance gene, designated as SacMi . The full-length cDNA of the SacMi gene was obtained using the technique of rapid-amplification of cDNA ends (RACE). The open reading frame of the SacMi gene was 4014 bp and encoded a protein of 1338 amino acids. Sequence analysis indicated that SacMi belong to the non- Toll/Interleukin-1 receptor (TIR)-NBS-LRR type disease-resistance genes. Interestingly, quantitative RT-PCR showed that SacMi is expressed at low levels in uninfected roots, but was up-regulated by infection with M. incognita . To investigate the role of SacMi in S. aculeatissimum resistance against M. incognica , the tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS) system was used. Silencing of SacMi enhanced susceptibility of S. aculeatissimum plants to M. incognita , suggesting the possible involvement of SacMi in resistance against M. incognita infection.

  20. In vitro uptake of 140 kDa Bacillus thuringiensis nematicidal crystal proteins by the second stage juvenile of Meloidogyne hapla.

    Directory of Open Access Journals (Sweden)

    Fengjuan Zhang

    Full Text Available Plant-parasitic nematodes (PPNs are piercing/sucking pests, which cause severe damage to crops worldwide, and are difficult to control. The cyst and root-knot nematodes (RKN are sedentary endoparasites that develop specialized multinucleate feeding structures from the plant cells called syncytia or giant cells respectively. Within these structures the nematodes produce feeding tubes, which act as molecular sieves with exclusion limits. For example, Heterodera schachtii is reportedly unable to ingest proteins larger than 28 kDa. However, it is unknown yet what is the molecular exclusion limit of the Meloidogyne hapla. Several types of Bacillus thuringiensis crystal proteins showed toxicity to M. hapla. To monitor the entry pathway of crystal proteins into M. hapla, second-stage juveniles (J2 were treated with NHS-rhodamine labeled nematicidal crystal proteins (Cry55Aa, Cry6Aa, and Cry5Ba. Confocal microscopic observation showed that these crystal proteins were initially detected in the stylet and esophageal lumen, and subsequently in the gut. Western blot analysis revealed that these crystal proteins were modified to different molecular sizes after being ingested. The uptake efficiency of the crystal proteins by the M. hapla J2 decreased with increasing of protein molecular mass, based on enzyme-linked immunosorbent assay analysis. Our discovery revealed 140 kDa nematicidal crystal proteins entered M. hapla J2 via the stylet, and it has important implications in designing a transgenic resistance approach to control RKN.

  1. Chitosan Increases Tomato Root Colonization by Pochonia chlamydosporia and Their Combination Reduces Root-Knot Nematode Damage

    Directory of Open Access Journals (Sweden)

    Nuria Escudero

    2017-09-01

    Full Text Available The use of biological control agents could be a non-chemical alternative for management of Meloidogyne spp. [root-knot nematodes (RKN], the most damaging plant-parasitic nematodes for horticultural crops worldwide. Pochonia chlamydosporia is a fungal parasite of RKN eggs that can colonize endophytically roots of several cultivated plant species, but in field applications the fungus shows a low persistence and efficiency in RKN management. The combined use of P. chlamydosporia with an enhancer could help its ability to develop in soil and colonize roots, thereby increasing its efficiency against nematodes. Previous work has shown that chitosan enhances P. chlamydosporia sporulation and production of extracellular enzymes, as well as nematode egg parasitism in laboratory bioassays. This work shows that chitosan at low concentrations (up to 0.1 mg ml-1 do not affect the viability and germination of P. chlamydosporia chlamydospores and improves mycelial growth respect to treatments without chitosan. Tomato plants irrigated with chitosan (same dose limit increased root weight and length after 30 days. Chitosan irrigation increased dry shoot and fresh root weight of tomato plants inoculated with Meloidogyne javanica, root length when they were inoculated with P. chlamydosporia, and dry shoot weight of plants inoculated with both P. chlamydosporia and M. javanica. Chitosan irrigation significantly enhanced root colonization by P. chlamydosporia, but neither nematode infection per plant nor fungal egg parasitism was affected. Tomato plants cultivated in a mid-suppressive (29.3 ± 4.7% RKN egg infection non-sterilized clay loam soil and irrigated with chitosan had enhanced shoot growth, reduced RKN multiplication, and disease severity. Chitosan irrigation in a highly suppressive (73.7 ± 2.6% RKN egg infection sterilized-sandy loam soil reduced RKN multiplication in tomato. However, chitosan did not affect disease severity or plant growth irrespective of

  2. Seleção de clones de batata-doce resistentes a Meloidogyne incognita raça 1 Selection of sweetpotato clones resistant to Meloidogyne incognita race 1

    Directory of Open Access Journals (Sweden)

    Aline Marchese

    2010-09-01

    Full Text Available O objetivo deste trabalho foi selecionar clones de batata-doce (Ipomoea batatas resistentes à raça 1 de Meloidogyne incognita e avaliar a eficiência do método de seleção empregado, pela estimação dos coeficientes de variação genética e ambiental e das herdabilidades no sentido amplo. Foram utilizados 123 genótipos de batata-doce, entre os quais quatro cultivares comerciais - Brazlândia Rosada, Brazlândia Roxa, Brazlândia Branca e Palmas -, e 119 acessos previamente selecionados no programa de melhoramento vegetal da Universidade Federal de Lavras. O delineamento experimental utilizado foi o de blocos aumentados, com três tratamentos comuns: as cultivares de batata-doce Brazlândia Branca e Palmas, e a cultivar de tomate Santa Clara, suscetível ao nematoide. A classificação dos níveis de resistência foi realizada de acordo com o fator de reprodução do nematoide e o índice de reprodução relativo à cultivar Santa Clara, de tomateiro. A relação entre os coeficientes de variação genética e ambiental e as herdabilidades no sentido amplo foram altas, tanto para o fator de reprodução quanto para o índice de reprodução dos nematoides, o que demonstra a eficiência do método empregado para a seleção de genótipos resistentes. Foram identificados 57 genótipos promissores de batata-doce, resistentes à raça 1 de M. incognita, e selecionados para continuar no programa de melhoramento.The objective of this work was to select sweetpotato (Ipomoea batatas resistant clones to Meloidogyne incognita race 1, and to assess the efficiency of the selection method deployed, through the estimation of genetic and environmental coefficients of variation, and broad-sense heritabilities. Genotypes assessed comprised 123 sweetpotato entries altogether, including four commercial cultivars - Brazlândia Rosada, Brazlândia Roxa, Brazlândia Branca, Palmas - and 119 clones previously selected by the Universidade Federal de Lavras

  3. Enxertia e sua influencia na produção de pepino e reprodução de Meloidogyne javanica e M. incognita Effect of grafting on cucumber production and reproduction of Meloidogyne javanica and M. incognita

    Directory of Open Access Journals (Sweden)

    Ariane C Salata

    2012-12-01

    Full Text Available A enxertia em porta-enxertos resistentes é uma técnica frequentemente recomendada para a cultura do pepino em áreas infestadas com nematoides-das-galhas. O presente trabalho teve como objetivo avaliar a produção de pepino enxertado em dois porta-enxertos comparado com pé-franco em solo infestado com Meloidogyne incognita raça 2 ou com M. javanica. Foram avaliados nove tratamentos (fatorial 3x3: pepino híbrido Tsuyataro pé-franco, enxertado na abóbora híbrida 'Shelper' e enxertado na abóbora híbrida 'Excitte Ikki' x sem inoculação, inoculação com M. incognita e inoculação com M. javanica, no delineamento em blocos ao acaso, com quatro repetições e seis plantas por parcela. Para as características de produção de frutos (número de frutos totais e comerciais por planta, massa de frutos totais e comerciais por planta não foi obtida interação entre os fatores. Obteve-se maior produção de frutos em plantas enxertadas sobre a abóbora 'Shelper', independente da espécie de nematoide, enquanto que a enxertia sobre 'Excitte Ikki' não diferiu do pé-franco para produção total. Ambas as espécies de nematoide reduziram a produção de frutos, porém este efeito foi mais pronunciado com M. javanica. Tanto o pepino pé-franco como as plantas enxertadas foram suscetíveis, pois permitiram a multiplicação dos nematoides, com fator de reprodução, em avaliação realizada aos 72 dias após a inoculação, variando de 3,57 a 15,04, sendo que para M. javanica este valor foi maior no pepino pé-franco.Grafting on resistant rootstock is a technique often recommended for cucumber crop in root-knot nematodes infested areas. We studied the yield of grafted cucumber on two rootstocks compared with non grafted in soil infested with Meloidogyne javanica or with M. incognita race 2. Nine treatments (factorial 3x3: Japanese cucumber hybrid Tsuyataro without grafting, grafted on squash hybrid Shelper and grafted on squash hybrid Excitte

  4. A TaqMan real-time PCR assay for detection of Meloidogyne hapla in root galls and in soil

    DEFF Research Database (Denmark)

    Sapkota, Rumakanta; Skantar, Andrea M.; Nicolaisen, Mogens

    2016-01-01

    . haplaand showed no significant amplification of DNA from non-target nematodes. The assay was able to detect M. haplain a background of plant and soil DNA. A dilution series of M. haplaeggs in soil showed a high correlation ( R 2 = 0 . 95 , P ...Early detection and quantification of Meloidogyne haplain soil is essential for effective disease management. The purpose of this study was to develop a real-time PCR assay for detection of M. haplain soil. Primers and a TaqMan probe were designed for M. hapladetection. The assay detected M......-knot development in carrots by testing soils before planting. The assay could be useful for management decisions in carrot cultivation....

  5. Efecto del follaje de Tagetes minutasobre la nodulación radicular de Meloidogyne incognitaen Capsicum annuum, en invernadero Effect of the foliage of Tagetes minutaon Meloidogyne incognitaroot-galling on Capsicum annuumin a greenhouse

    Directory of Open Access Journals (Sweden)

    Santos Nélida Murga-Gutiérrez

    2013-06-01

    Full Text Available Se investigó el efecto del follaje del “huacatay” Tagetes minutasobre la nodulación radicular producida por el nematodo Meloidogyne incognitaque parasita el “pimiento páprika” Capsicum annuumcultivado en invernadero, con la finalidad de obtener una alternativa de control de este nematodo. Se utilizaron tres grupos experimentales y un testigo, con 12 macetas cada uno, las cuales contenían suelo y arena estériles (1:1. A este substrato se adicionó el follaje de T. minutaal 20, 35 y 50% (v/v según grupo experimental, y el testigo no recibió esta enmienda. En cada maceta se sembró una plántula de C. annuum, y a la semana postsiembra se inoculó 5000 huevos de M. incognita.A las ocho semanas, se evaluaron los nódulos en sus raíces. Todas las plantas presentaron nódulos; aunque, en aquellas de los grupos experimentales el número de éstos fue menor que en las plantas testigo, con diferencia estadística significativa (p 0,05. Se concluye que el follaje de T. minutaadicionado como enmienda orgánica al 20, 35 y 50% al suelo de cultivo de plantas de C. annuum limita la nodulación radicular ocasionada por M. incognita. Lo cual sugiere su uso potencial en el control de este nematodo.The effect of the foliage of Tagetes minuta"huacatay" on Meloidogyne incognitaroot-galling on Capsicum annuum"paprika pepper" cultured in a greenhouse was researched, to obtain a control strategy for this nema-tode. Three experimental groups and one control with 12 pots each were used, which contained sterilized soil and sand (1:1. To this substrate was added cut foliage of T. minutaat 20, 35 and 50% (v/v according to the experimental group, and the control group remained without this amendment. In each pot a seedling of C. annuum was sown, and one week post-seeding was inoculated with 5000 eggs of M. incognita. Eight weeks later the root galling was evaluated. All the plants had root galling; although the number of galls in plants of the experimental

  6. Survey of crop losses in response to phytoparasitic nematodes in the United States for 1994.

    Science.gov (United States)

    Koenning, S R; Overstreet, C; Noling, J W; Donald, P A; Becker, J O; Fortnum, B A

    1999-12-01

    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 extension personnel in 49 U.S. states for information on estimated crop losses caused by plant-parasitic nematodes in major crops for the year 1994. Included in this paper are survey results from 35 states on various crops including corn, cotton, soybean, peanut, wheat, rice, sugarcane, sorghum, tobacco, numerous vegetable crops, fruit and nut crops, and golf greens. The data are reported systematically by state and include the estimated loss, hectarage of production, source of information, nematode species or taxon when available, and crop value. The major genera of phytoparasitic nematodes reported to cause crop losses were Heterodera, Hoplolaimus, Meloidogyne, Pratylenchus, Rotylenchulus, and Xiphinema.

  7. Species Composition and Structure of the Communities of Plant-Parasitic and Free-Living Soil Nematodes in the Greenhouses of Botanical Gardens of Ukraine

    Directory of Open Access Journals (Sweden)

    Gubin A.I.

    2014-07-01

    Full Text Available Species Composition and Structure of the Communities of Plant-Parasitic and Free-Living Soil Nematodes in the Greenhouses of Botanical Gardens of Ukraine. Gubin, A. I., Sigareva, D. D. — In greenhouses of botanical gardens of Ukraine 81 species of nematodes were found. The richest by the number of species was Tylenchida order that was presented by 25 species (31 % of species composition. The dominant group of nematodes was plant-parasitic (most frequent was Rotylenchus robustus (de Man, 1876 Filipjev, 1936 and Meloidogyne incognita (Kofoid et White, 1919 Chitwood, 1949. The group of saprobiotic nematodes, which was presented by 52 species (64 %, appeared to be the richest by the number of species. It is shown, that formation of nematode communities in greenhouses of botanical gardens was caused by the interaction of many related factors, crucial of which is the composition of plant collections. The structure of communities is quite constant and almost independent of the quantity of nematodes species. Plant-parasitic species dominate by the number and frequency of detection, and represent a kind of a core of nematode communities.

  8. Control of Meloidogyne javanica and M. arenaria on kenaf and roselle with genetic resistance and nematicides

    Science.gov (United States)

    Minton, N. A.; Adamson, W. C.

    1979-01-01

    Kenaf (Hibiscus cannabinus) and roselle (H. sabdarifla) were evaluated in nematicide-treated and untreated field soil naturally infested with either Meloidogyne javanica or M. arenaria. Root-knot indices indicated that the kenaf breeding line j-l-113 had moderate resistance to M. javanica and low resistance to M. arenaria. Kenaf cv Everglades 71 was highly susceptible to both M. javanica and M. arenaria, and roselle breeding line A59-56 was highly resistant. Both nematode species reproduced on all plant entries, but more larvae were recovered from the soil in plots planted to Everglades 71 than in plots planted to j-l-l13 or A59-56. In untreated soil infested with M. javanica, dry-matter yields were greater (P = 0.05) for j-l-l13 and A59-56 than for Everglades 71. The percentages of live plants at harvest were: j-l-l13, 88; A59-56, 93; and Everglades 71, 9. Ethylene dibromide (1,2-dibromoethane) at 73.9 kg a.i./ha and DBCP (1,2-dibromo-3-chloropropane) at 17.6 kg a.i./ha increased dry-matter yields significantly for all entries planted in soil infested with M. arenaria. Carbofuran (2.3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) at 5.9 kg a.i./ha did not increase the dry-matter yields of any entry. None of the nematicides increased the growth of any entry significantly in soil infested with M. javanica. PMID:19305526

  9. How to reduce the number of Meloidogyne paranaensis galls in tomato using earthworms?

    Directory of Open Access Journals (Sweden)

    Jair Alves Dionísio

    2014-02-01

    Full Text Available The objective of the present work was to determine the incidence of Meloidogyne paranaensis galls in the roots of Solanum lycopersicum, after inoculation with Amynthas spp. and Pontoscolex corethrurus. The experiment was performed in the greenhouse in a randomised block experimental design was adopted, with four treatments and five repetitions: T1. M. paranaensis; T2. M. paranaensis + Amynthas spp. T3. M. paranaensis +P. corethrurus; T4. M. paranaensis + Amynthas spp. + P. corethrurus. Initially, six adult worms of Amynthas spp. or P. corethrurus, isolated or in the same proportion (3:3, with the previously determined fresh biomass. After one week, tomato seedlings (cultivar “Rutgers” were transplanted to the pots and inoculated with 5 mL of a suspension of M. paranaensis containing 5,000 eggs and/or juveniles per pot. Sixty-five days after inoculation, the number of remaining worms was counted after manual collection; the fresh biomass was determined by direct weighing, and the number of galls on the roots of the tomato was counted directly in a stereomicroscope. The results demonstrated a reduction in the number of galls per plant with treatments involving inoculation with worms, varying between 26,7% and 63,3%, respectively, for Amynthas spp. and P. corethrurus. Meanwhile, the combination of worms lead to a reduction of 50,0% in the incidence of galls. The results demonstrate that the use of worms in the biological control of nematodes, during tomato cultivation, has great potential that requires further investigation.

  10. Biological Control of Meloidogyne incognita by Aspergillus niger F22 Producing Oxalic Acid.

    Science.gov (United States)

    Jang, Ja Yeong; Choi, Yong Ho; Shin, Teak Soo; Kim, Tae Hoon; Shin, Kee-Sun; Park, Hae Woong; Kim, Young Ho; Kim, Hun; Choi, Gyung Ja; Jang, Kyoung Soo; Cha, Byeongjin; Kim, In Seon; Myung, Eul Jae; Kim, Jin-Cheol

    2016-01-01

    Restricted usage of chemical nematicides has led to development of environmentally safe alternatives. A culture filtrate of Aspergillus niger F22 was highly active against Meloidogyne incognita with marked mortality of second-stage juveniles (J2s) and inhibition of egg hatching. The nematicidal component was identified as oxalic acid by organic acid analysis and gas chromatography-mass spectroscopy (GC-MS). Exposure to 2 mmol/L oxalic acid resulted in 100% juvenile mortality at 1 day after treatment and suppressed egg hatching by 95.6% at 7 days after treatment. Oxalic acid showed similar nematicidal activity against M. hapla, but was not highly toxic to Bursaphelenchus xylophilus. The fungus was incubated on solid medium and dried culture was used for preparation of a wettable powder-type (WP) formulation as an active ingredient. Two WP formulations, F22-WP10 (ai 10%) and oxalic acid-WP8 (ai 8%), were prepared using F22 solid culture and oxalic acid. In a field naturally infested with M. incognita, application of a mixture of F22-WP10 + oxalic acid-WP8 at 1,000- and 500-fold dilutions significantly reduced gall formation on the roots of watermelon plants by 58.8 and 70.7%, respectively, compared to the non-treated control. The disease control efficacy of the mixture of F22-WP10 + oxalic acid-WP8 was significantly higher than that of a chemical nematicide, Sunchungtan (ai 30% fosthiazate). These results suggest that A. niger F22 can be used as a microbial nematicide for the control of root-knot nematode disease.

  11. Biological Control of Meloidogyne incognita by Aspergillus niger F22 Producing Oxalic Acid.

    Directory of Open Access Journals (Sweden)

    Ja Yeong Jang

    Full Text Available Restricted usage of chemical nematicides has led to development of environmentally safe alternatives. A culture filtrate of Aspergillus niger F22 was highly active against Meloidogyne incognita with marked mortality of second-stage juveniles (J2s and inhibition of egg hatching. The nematicidal component was identified as oxalic acid by organic acid analysis and gas chromatography-mass spectroscopy (GC-MS. Exposure to 2 mmol/L oxalic acid resulted in 100% juvenile mortality at 1 day after treatment and suppressed egg hatching by 95.6% at 7 days after treatment. Oxalic acid showed similar nematicidal activity against M. hapla, but was not highly toxic to Bursaphelenchus xylophilus. The fungus was incubated on solid medium and dried culture was used for preparation of a wettable powder-type (WP formulation as an active ingredient. Two WP formulations, F22-WP10 (ai 10% and oxalic acid-WP8 (ai 8%, were prepared using F22 solid culture and oxalic acid. In a field naturally infested with M. incognita, application of a mixture of F22-WP10 + oxalic acid-WP8 at 1,000- and 500-fold dilutions significantly reduced gall formation on the roots of watermelon plants by 58.8 and 70.7%, respectively, compared to the non-treated control. The disease control efficacy of the mixture of F22-WP10 + oxalic acid-WP8 was significantly higher than that of a chemical nematicide, Sunchungtan (ai 30% fosthiazate. These results suggest that A. niger F22 can be used as a microbial nematicide for the control of root-knot nematode disease.

  12. Host Suitability of 32 Common Weeds to Meloidogyne hapla in Organic Soils of Southwestern Quebec

    Science.gov (United States)

    Bélair, G.; Benoit, D. L.

    1996-01-01

    Thirty-two weeds commonly found in the organic soils of southwestern Quebec were evaluated for host suitability to a local isolate of the northern root-knot nematode Meloidogyne hapla under greenhouse conditions. Galls were observed on the roots of 21 species. Sixteen of the 21 had a reproduction factor (Pf/Pi = final number of M. hapla eggs and juveniles per initial number of M. hapla juveniles per pot) higher than carrot (Pf/Pi = 0.37), the major host crop in this agricultural area. Tomato cv. Rutgers was also included as a susceptible host and had the highest Pf/Pi value of 13.7. Bidens cernua, B. frondosa, B. vulgata, Erysimum cheiranthoides, Eupatorium maculatum, Matricaria matricarioides, Polygonum scabrum, Thalictrum pubescens, Veronica agrestis, and Sium suave are new host records for M. hapla. Bidens cernua, B. frondosa, B. wulgata, D. carota, M. matricarioides, Pasticana sativa, P. scabrum, S. suave, and Thlaspi arvense sustained moderate to high galling by M. hapla and supported high M. hapla production (12.4 ≤ Pf/Pi ≥ 2.9). Capsella bursa-pastoris, Chrysanthemum leucanthemum, Gnaphalium uliginosum, Stellaria media, and Veronica agrestis sustained moderate galling and supported moderate M. hapla reproduction (2.8 ≤ Pf/Pi ≥ 0.5). Chenopodium album, C. glaucum, E. cheiranthoides, P. convolvulus, Portulaca oleracea, and Rorippa islandica supported low reproduction (0.25 ≤ Pf/Pi ≥ 0.02) and sustained low galling. Galling was observed on Senecio vulgaris but no eggs or juveniles; thus, S. vulgaris may be useful as a trap plant. Eupatorium maculatum, and T. pubescens harbored no distinct galling but supported low to moderate M. hapla reproduction, respectively. Amaranthus retroflexus, Ambrosia artemisiifolia, Echinochloa crusgalli, Erigeron canadensis, Oenothera parviflora, Panicum capillare, Setaria glauca, S. viridis, and Solidago canadensis were nonhosts. Our results demonstrate the importance of adequate weed control in an integrated program

  13. Characterization of Streptomyces netropsis Showing a Nematicidal Activity against Meloidogyne incognita

    Directory of Open Access Journals (Sweden)

    Ja Yeong Jang

    2015-06-01

    Full Text Available Control of nematode has become difficult owing to the restricted use of effective soil fumigant, methyl bromide, and other non-fumigant nematicides. Therefore, it is urgently necessary to develop microbial nematicide to replace chemical nematicides. In this study, the 50% aqueous methanol extraction solution of fermentation broths of 2,700 actinomycete strains were tested for their nematicidal activity against second stage of juveniles (J2s of Meloidogyne incognita. As the results, only the 50% aqueous methanol extraction solution of AN110065, at 20% equivalent to 10% fermentation broth, showed strong nematicidal activity with 78.9% of mortality 24 h after treatment and 94.1% of mortality at 72 h. The 16S rRNA gene sequencing showed that the strain sequence was 99.78% identical to Streptomyces netropsis. The extract of S. netropsis AN110065 fermentation broth was successively partitioned with ethyl acetate and butanol and then the ethyl acetate, butanol and water layers were investigated for their nematicidal activity against the M. incognita. At 1,000 mg/ml, ethyl acetate layer showed the strongest activity of 83.5% of juvenile mortality 72 h after treatment. The pot experiment using the fermentation broth of AN110065 on tomato plant against M. incognita displayed that it evidently suppressed gall formation at a 10-fold diluent treatment. The tomato plants treated with the fermentation broth of S. netropsis AN110065 did not show any phytotoxicity. The results suggest that S. netropsis AN110065 has a potential to serve as microbial nematicide in organic agriculture.

  14. Nematicidal activity of acetophenones and chalcones against Meloidogyne incognita and structure-activity considerations.

    Science.gov (United States)

    Caboni, Pierluigi; Aissani, Nadhem; Demurtas, Monica; Ntalli, Nikoletta; Onnis, Valentina

    2016-01-01

    With the ultimate goal of identifying new compounds active against root-knot nematodes, a set of 14 substituted chalcones were synthesised, starting from acetophenones. These chalcones and various acetophenones were tested in vitro against Meloidogyne incognita. The most potent acetophenones were 4-nitroacetophenone and 4-iodoacetophenone, with EC(50/24 h) values of 12 ± 5 and 15 ± 4 mg L(-1) respectively, somewhat weaker than that of the chemical control fosthiazate in our previous experiments (EC(50/24 h) 0.4 ± 0.3 mg L(-1)). When we converted the acetophenones to chalcones, the nematicidal activity differed, based on their substitution pattern. The condensation of 4-nitroacetophenone with 2,4,6-trihydroxybenzaldehyde to give the corresponding chalcone (E)-1-(4-nitrophenyl)-3-(2,4,6-trihydroxyphenyl)prop-2-en-1-one led to a slight reduction in activity (EC(50/24 h) value 25 ± 17 mg L(-1)). Moreover, (E)-3-(2-hydroxy-5-iodophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one showed better activity (EC(50/24) h value 26 ± 15 mg L(-1)) than 4-methoxyacetophenone (EC(50/24 h) value 43 ± 10 mg L(-1)). Acetophenones and chalcones may represent good leads in the discovery of new nematicidal compounds and may have potential use in crop management as active ingredients. © 2015 Society of Chemical Industry.

  15. Using relative penetration and maleness indices in Meloidogyne ...

    African Journals Online (AJOL)

    Resistance in plant-parasitic nematodes is broadly classified as pre-infectional or post-infectional. Prebreeding establishment of resistance type in plant-parasitic nematodes is essential where germplasm is to be introgressed into the rootstock breeding lines since only post-infectional resistance is introgressible. A study ...

  16. Effect of a Terminated Cover Crop and Aldicarb on Cotton Yield and Meloidogyne incognita Population Density.

    Science.gov (United States)

    Wheeler, T A; Leser, J F; Keeling, J W; Mullinix, B

    2008-06-01

    Terminated small grain cover crops are valuable in light textured soils to reduce wind and rain erosion and for protection of young cotton seedlings. A three-year study was conducted to determine the impact of terminated small grain winter cover crops, which are hosts for Meloidogyne incognita, on cotton yield, root galling and nematode midseason population density. The small plot test consisted of the cover treatment as the main plots (winter fallow, oats, rye and wheat) and rate of aldicarb applied in-furrow at-plant (0, 0.59 and 0.84 kg a.i./ha) as subplots in a split-plot design with eight replications, arranged in a randomized complete block design. Roots of 10 cotton plants per plot were examined at approximately 35 days after planting. Root galling was affected by aldicarb rate (9.1, 3.8 and 3.4 galls/root system for 0, 0.59 and 0.84 kg aldicarb/ha), but not by cover crop. Soil samples were collected in mid-July and assayed for nematodes. The winter fallow plots had a lower density of M. incognita second-stage juveniles (J2) (transformed to Log(10) (J2 + 1)/500 cm(3) soil) than any of the cover crops (0.88, 1.58, 1.67 and 1.75 Log(10)(J2 + 1)/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). There were also fewer M. incognita eggs at midseason in the winter fallow (3,512, 7,953, 8,262 and 11,392 eggs/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). Yield (kg lint per ha) was increased by application of aldicarb (1,544, 1,710 and 1,697 for 0, 0.59 and 0.84 kg aldicarb/ha), but not by any cover crop treatments. These results were consistent over three years. The soil temperature at 15 cm depth, from when soils reached 18 degrees C to termination of the grass cover crop, averaged 9,588, 7,274 and 1,639 centigrade hours (with a minimum threshold of 10 degrees C), in 2005, 2006 and 2007, respectively. Under these conditions, potential reproduction of M. incognita on the cover crop did not result in a yield penalty.

  17. Nematode cholinergic pharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Segerberg, M.A.

    1989-01-01

    Nematode acetylcholine (ACh) receptors were characterized using both biochemical and electrophysiological techniques, including: (1) receptor binding studies in crude homogenates of the free-living nematode Caenorhabditis elegans and the parasitic nematode Ascaris lumbricoides with the high-affinity probe ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) which binds to muscarinic receptors in many vertebrate and invertebrate tissues (2) measurement of depolarization and contraction induced by a variety of cholinergic agents, including N-methylscopolamine (NMS), in an innervated dorsal muscle strip preparation of Ascaris; (3) examination of the antagonistic actions of d-tubocurarine (dTC) and NMS at dorsal neuromuscular junction; (4) measurement of input resistance changes in Ascaris commissural motorneurons induced by ACh, dTC, NMS, pilocarpine and other cholinergic drugs.

  18. Optimization of In Vitro Techniques for Distinguishing between Live and Dead Second Stage Juveniles of Heterodera glycines and Meloidogyne incognita.

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    Ni Xiang

    Full Text Available Heterodera glycines (Soybean Cyst nematode, or SCN and Meloidogyne incognita (Root-Knot nematode, or RKN are two damaging plant-parasitic nematodes on important field crops. Developing a quick method to distinguish between live and dead SCN and RKN second stage juveniles (J2 is vital for high throughput screening of pesticides or biological compounds against SCN and RKN. The in vitro assays were conducted in 96-well plates to determine the optimum chemical stimulus to distinguish between live and dead SCN and RKN J2. Sodium carbonate (Na2CO3, sodium bicarbonate (NaHCO3, and sodium hydroxide (NaOH were evaluated for the nematode response to see if these compounds can help distinguish between viable from the dead J2. Results indicated that live SCN J2 responded equally (P ≤ 0.05 to 1 μl Na2CO3 and 10 μl NaHCO3 in 100 μl of water at pH = 10. Live SCN J2 responded by twisting their bodies in a curling shape and increasing rate of movements within 2 minutes of exposure. The twisting activity continued for up to 30 minutes. Live RKN J2 responded by increasing activity with the application of 1 μl NaOH in 100 μl of water at pH = 10 also in the 2 minutes to 30 minutes time frame. Furthermore, in growth chamber tests to confirm the infectivity of live SCN. The live SCN as determined by exposure to 1 μl of Na2CO3 indicated 60.5% of the SCN J2 were alive and of those, 29.5% were infective and entered the soybean roots. The 1 μl of NaOH stimulus revealed that 75.2% RKN J2 were alive and of those, 14.9% were infective and entered soybean roots. These results confirmed that 1 μl of Na2CO3 added to 100 μl suspension of SCN J2 and 1 μl of NaOH added to 100 μl suspension of RKN J2 are the effective stimuli for rapidly distinguishing between live and dead SCN and RKN J2 in vitro. SCN and RKN J2 responded differently to different compounds.

  19. Pochonia chlamydosporia var. chlamydosporia (Goddard Zare & W. Gams for the management of lettuce infected with Meloidogyne javanica (Treub, 1885

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    José R Viggiano

    2015-06-01

    Full Text Available The application of the nematophagous fungus Pochonia chlamydosporia var. chlamydosporia (Goddard Zare & W. Gams during seedling production of vegetable crops can be an efficient approach to control root-knot nematode. The aim of this study was to evaluate the effect of treating seedlings and/or soil with bionematicide (wettable powder formulation based on chlamydospores from isolate Pc-10 on the Meloidogyne javanica (Treub, 1885 control in lettuce (Lactuca sativa L.. Isolate Pc-10 was diluted in water and applied when watering the seedlings (0, 4.5, 9.0, 13.5, and 18.0 g L-1 and/or to the potted soil (5000 chlamydospores g-1 used for growing lettuce. The soil in each pot was infested with 3000 M. javanica eggs. The number of M. javanica eggs was reduced in lettuce roots when isolate Pc-10 was applied either to seedlings or soil; there was no interaction between application methods. The decrease in the number of eggs was proportional to the increase of isolate Pc-10 applied to seedlings with maximum reduction of 43.5% at the 18 g L-1 dose. When the fungus was applied to the soil, the number of eggs was reduced by 12.3%. Increasing doses of isolate Pc-10 reduced the number of galls up to 21% with the 18 g L-1 dose. Applying bionematicide based on P. chlamydosporia isolate Pc-10 at 18 g L-1 on seedlings controls M. javanica in lettuce.

  20. The complex hybrid origins of the root knot nematodes revealed through comparative genomics

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    David H. Lunt

    2014-05-01

    Full Text Available Root knot nematodes (RKN can infect most of the world’s agricultural crop species and are among the most important of all plant pathogens. As yet however we have little understanding of their origins or the genomic basis of their extreme polyphagy. The most damaging pathogens reproduce by obligatory mitotic parthenogenesis and it has been suggested that these species originated from interspecific hybridizations between unknown parental taxa. We have sequenced the genome of the diploid meiotic parthenogen Meloidogyne floridensis, and use a comparative genomic approach to test the hypothesis that this species was involved in the hybrid origin of the tropical mitotic parthenogen Meloidogyne incognita. Phylogenomic analysis of gene families from M. floridensis, M. incognita and an outgroup species Meloidogyne hapla was carried out to trace the evolutionary history of these species’ genomes, and we demonstrate that M. floridensis was one of the parental species in the hybrid origins of M. incognita. Analysis of the M. floridensis genome itself revealed many gene loci present in divergent copies, as they are in M. incognita, indicating that it too had a hybrid origin. The triploid M. incognita is shown to be a complex double-hybrid between M. floridensis and a third, unidentified, parent. The agriculturally important RKN have very complex origins involving the mixing of several parental genomes by hybridization and their extreme polyphagy and success in agricultural environments may be related to this hybridization, producing transgressive variation on which natural selection can act. It is now clear that studying RKN variation via individual marker loci may fail due to the species’ convoluted origins, and multi-species population genomics is essential to understand the hybrid diversity and adaptive variation of this important species complex. This comparative genomic analysis provides a compelling example of the importance and complexity of

  1. Effect of plant resistance and BioAct WG (Purpureocillium lilacinum strain 251) on Meloidogyne incognita in a tomato-cucumber rotation in a greenhouse.

    Science.gov (United States)

    Giné, Ariadna; Sorribas, Francisco J

    2017-05-01

    The effectiveness of combining resistant tomato with BioAct WG (Purpureocillium lilacinum strain 251, Pl251) against Meloidogyne incognita was assessed in a tomato-cucumber rotation in a greenhouse over 2 years. Additionally, the enzymatic activity of the fungus, the percentage of fungal egg and juvenile parasitism, cardinal temperatures and the effect of water potential on mycelial growth and the soil receptivity to Pl251 were determined in vitro. Plant resistance was the only factor that suppressed nematode and crop yield losses. Percentage of egg parasitism in plots treated with BioAct WG was less than 2.6%. However, under in vitro conditions, Pl251 showed protease, lipase and chitinase activities and parasitised 94.5% of eggs, but no juveniles. Cardinal temperatures were 14.2, 24-26 and 35.4 °C. The maximum Pl251 mycelial growth was at -0.25 MPa and 25 °C. Soil temperatures and water potential in the greenhouse were in the range of the fungus. However, soil receptivity was lower in greenhouse soil, irrespective of sterilisation, than in sterilised sand. Plant resistance was the only factor able to suppress nematode densities, disease severity and yield losses, and to protect the following cucumber crop. Environmental factors involved in soil receptivity could have negatively affected fungus effectiveness. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  2. Effects of Root Decay on the Relationship between Meloidogyne spp. Gall Index and Egg Mass Number in Cucumber and Horned Cucumber

    Science.gov (United States)

    Walters, S. Alan; Wehner, Todd C.; Barker, Kenneth R.

    1992-01-01

    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 necrosis affected the gall index-egg mass relationship. At lower root necrosis values, a stronger relationship existed between gall index and egg mass number than at higher root necrosis values. Root tissue was destroyed by root necrosis, and normal root-knot nematode reproduction would not occur, even though root galling was still observed. The races of M. incognita tested had a greater effect in predisposing C. sativus and C. metuliferus to root necrosis than did M. arenaria race 2 or M. javanica. This study showed that root necrosis had an adverse affect on the relationship between gall index and egg mass number in cucumber. PMID:19283049

  3. Root-knot nematodes induce pattern-triggered immunity in Arabidopsis thaliana roots.

    Science.gov (United States)

    Teixeira, Marcella A; Wei, Lihui; Kaloshian, Isgouhi

    2016-07-01

    Root-knot nematodes (RKNs; Meloidogyne spp.) are plant parasites with a broad host range causing great losses worldwide. To parasitize their hosts, RKNs establish feeding sites in roots known as giant cells. The majority of work studying plant-RKN interactions in susceptible hosts addresses establishment of the giant cells and there is limited information on the early defense responses. Here we characterized early defense or pattern-triggered immunity (PTI) against RKNs in Arabidopsis thaliana. To address PTI, we evaluated known canonical PTI signaling mutants with RKNs and investigated the expression of PTI marker genes after RKN infection using both quantitative PCR and β-glucuronidase reporter transgenic lines. We showed that PTI-compromised plants have enhanced susceptibility to RKNs, including the bak1-5 mutant. BAK1 is a common partner of distinct receptors of microbe- and damage-associated molecular patterns. Furthermore, our data indicated that nematode recognition leading to PTI responses involves camalexin and glucosinolate biosynthesis. While the RKN-induced glucosinolate biosynthetic pathway was BAK1-dependent, the camalexin biosynthetic pathway was only partially dependent on BAK1. Combined, our results indicate the presence of BAK1-dependent and -independent PTI against RKNs in A. thaliana, suggesting the existence of diverse nematode recognition mechanisms. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  4. Relationship between Psidium species (Myrtaceae) by resistance gene analog markers: focus on nematode resistance.

    Science.gov (United States)

    Noia, L R; Tuler, A C; Ferreira, A; Ferreira, M F S

    2017-03-16

    Guava (Psidium guajava L.) crop is severely affected by the nematode Meloidogyne enterolobii. Native Psidium species have been reported as sources of resistance against this nematode. Knowledge on the molecular relationship between Psidium species based on plant resistance gene analogs (RGA) can be useful in the genetic breeding of guava for resistance to M. enterolobii. In this study, RGA markers from conserved domains, and structural features of plant R genes, were employed to characterize Psidium species and establish genetic proximity, with a focus on nematode resistance. SSR markers were also applied owing to their neutral nature, thus differing from RGA markers. For this, species reported as sources of resistance to M. enterolobii, such as P. cattleianum and P. friedrichsthalianum, as well as species occurring in the Atlantic Rainforest and susceptible genotypes, were investigated. In 10 evaluated Psidium species, high interspecific genetic variability was verified through RGA and SSR markers, with intraspecific variation in P. guajava higher with SSR, as was expected. Resistant species were clustered by RGA markers, and differential amplicons among genotypes resistant and susceptible to M. enterolobii were identified. Knowledge on the molecular relationships between Psidium species constitutes useful information for breeding of the guava tree, providing direction for hybridization and material for rootstocks. Additionally, the genetic relationship between native species, which have been little studied, and P. guajava were estimated by RGAs, which were confirmed as important markers for genetic diversity related to pathogen resistance.

  5. Gall-forming root-knot nematodes hijack key plant cellular functions to induce multinucleate and hypertrophied feeding cells.

    Science.gov (United States)

    Favery, Bruno; Quentin, Michaël; Jaubert-Possamai, Stéphanie; Abad, Pierre

    2016-01-01

    Among plant-parasitic nematodes, the root-knot nematodes (RKNs) of the Meloidogyne spp. are the most economically important genus. RKN are root parasitic worms able to infect nearly all crop species and have a wide geographic distribution. During infection, RKNs establish and maintain an intimate relationship with the host plant. This includes the creation of a specialized nutritional structure composed of multinucleate and hypertrophied giant cells, which result from the redifferentiation of vascular root cells. Giant cells constitute the sole source of nutrients for the nematode and are essential for growth and reproduction. Hyperplasia of surrounding root cells leads to the formation of the gall or root-knot, an easily recognized symptom of plant infection by RKNs. Secreted effectors produced in nematode salivary glands and injected into plant cells through a specialized feeding structure called the stylet play a critical role in the formation of giant cells. Here, we describe the complex interactions between RKNs and their host plants. We highlight progress in understanding host plant responses, focusing on how RKNs manipulate key plant processes and functions, including cell cycle, defence, hormones, cellular scaffold, metabolism and transport. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Incidence and Identification of Root-Knot Nematode in Plastic-House Fields of Central Area of Korea

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    Hyoung Rai Ko

    2017-12-01

    Full Text Available To investigate occurrence of root-knot nematode (RKN in plastic house of central area of Korea, 132 soil samples were collected in cucumber, water melon, tomato, red pepper and strawberry fields from 2013 to 2015. Among 132 soil samples, 65 soil samples (49% were infested with RKN and mean density of RKN was 178 second-stage juveniles per 100 cm³ soil (min. 1 ~ max. 3,947. The frequency of RKN by regional was the highest in Chuncheon with 80%, followed by Cheonan (68%, Nonsan (36%, Buyeo (33% and Yesan (30%. The frequency of RKN by crops was the highest in tomato with 83%, followed by cucumber (61%, strawberry (41%, red pepper (30%, watermelon (26%. To identify the species of RKN, fifteen populations were selected for representative populations. As a phylogenetic analysis of 15 populations, southern root-knot nematode (Meloidogyne incognita, peanut root-knot nematode (M. arenaria and northern root-knot nematode (M. hapla were identified with 47%, 20% and 33% ratio, respectively. In crops, M. incognita, M. arenaria and M. hapla were detected in tomato, M. incognita and M. arenaria were detected in cucumber and watermelon, and M. hapla was detected in strawberry and lettuce. Thus, there should be a continuous management to major species of each crops to prevent dispersal of RKN damages.

  7. Plant-parasitic nematodes associated with olive tree (Olea europaea L.) with a focus on the Mediterranean Basin: a review.

    Science.gov (United States)

    Ali, Nadine; Chapuis, Elodie; Tavoillot, Johannes; Mateille, Thierry

    2014-01-01

    The olive tree (Olea europaea ssp. europaea.) is one of the most ancient cultivated trees. It is an emblematic species owing to its ecological, economic and cultural importance, especially in the Mediterranean Basin. Plant-parasitic nematodes are major damaging pests on olive trees, mainly in nurseries. They significantly contribute to economic losses in the top-ten olive-producing countries in the world. However, the damages they induce in orchards and nurseries are specifically documented only in a few countries. This review aims to update knowledge about the olive-nematode pathosystem by: (1) updating the list of plant-parasitic nematodes associated with olive trees; (2) analysing their diversity (taxonomic level, trophic groups, dominance of taxa), which allowed us (i) to assess the richness observed in each country, and (ii) to exhibit and describe the most important taxa able to induce damages on olive trees such as: Meloidogyne, Pratylenchus, Helicotylenchus, Xiphinema, Tylenchulus, Rotylenchulus, Heterodera (distribution especially in the Mediterranean Basin, pathogenicity and reactions of olive trees); (3) describing some management strategies focusing on alternative control methods; (4) suggesting new approaches for controlling plant-parasitic nematodes based on the management of the diversity of their communities, which are structured by several environmental factors such as olive diversity (due to domestication of wild olive in the past, and to breeding now), cropping systems (from traditional to high-density orchards), irrigation, and terroirs. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  8. EVALUATION OF TRICHODERMA SPP. ON BEAN CULTURE, IN ANTHRACNOSE, WEB BLIGHT AND ROOT-KNOT NEMATODE

    Directory of Open Access Journals (Sweden)

    P. E. V. Aguiar

    2014-09-01

    Full Text Available Mato Grosso is the third largest producer of bean from Brazil, being the third harvest (irrigated the most productive, but diseases such as anthracnose, web blight and nematodes of galls cause losses to producers. In addition, a measure widely used and little studied for the control of diseases and nematodes in Mato Grosso is the biological control, which consists of the action of other microorganisms on phytopathogens. Thus, the objective of the present study was to evaluate the effect of Trichoderma harzianum and T. asperellum in the development (height of plants, chlorophyll and number of pods of culture of bean, in the control of anthracnose (Colletotrichum lindemuthianum, web blight (Rhizoctonia solani and in the population of Meloidogyne spp. in the soil. The experiment was accomplished in area experimental of University Federal of Mato Grosso/Campus Sinop. The experimental design was of entirely randomized with 12 parcels of 5m² each, with 3 treatments and 4 replications. The cultivar used was Whitey, carioca group, and the seed treatment performed with product Pyraclostrobin + Thiophanate Methyl + Fipronil and after drying of the inoculation of biocontrol agents and manual seeding. It was observed that the application of T. harzianum and T. asperellum, not promoted increase of chlorophyll, height of plants in bean culture, without reducing the population of Meloidogyne spp.. However, biocontrol agents have reduced the severity of anthracnose and web blight and promoted an increase in the average number of plant pods-1. It is therefore concluded that biocontrol agents show potential for application in bean culture in the North of Mato Grosso.

  9. Efficacy of Various Application Methods of Fluensulfone for Managing Root-knot Nematodes in Vegetables.

    Science.gov (United States)

    Morris, Kelly A; Langston, David B; Davis, Richard F; Noe, James P; Dickson, Don W; Timper, Patricia

    2016-06-01

    Fluensulfone is a new nematicide in the flouroalkenyl chemical group. A field experiment was conducted in 2012 and 2013 to evaluate the efficacy of various application methods of fluensulfone for control of Meloidogyne spp. in cucumber (Cucumis sativus). Treatments of fluensulfone (3.0 kg a.i./ha) were applied either as preplant incorporation (PPI) or via different drip irrigation methods: drip without pulse irrigation (Drip NP), pulse irrigation 1 hr after treatment (Drip +1P), and treatment at the same time as pulse irrigation (Drip =P). The experiment had eight replications per treatment and also included a PPI treatment of oxamyl (22.5 kg a.i./ha) and a nontreated control. Compared to the control, neither the oxamyl nor the fluensulfone PPI treatments reduced root galling by Meloidogyne spp. in cucumber. Among the drip treatments, Drip NP and Drip +1P reduced root galling compared to the control. Cucumber yield was greater in all fluensulfone treatments than in the control. In a growth-chamber experiment, the systemic activity and phytotoxicity of fluensulfone were also evaluated on tomato (Solanum lycopersicum), eggplant (Solanum melongena), cucumber, and squash (Curcurbita pepo). At the seedling stage, foliage of each crop was sprayed with fluensulfone at 3, 6, and 12 g a.i./liter, oxamyl at 4.8 g a.i./liter, or water (nontreated control). Each plant was inoculated with Meloidogyne incognita juveniles 2 d after treatment. There were six replications per treatment and the experiment was conducted twice. Foliar applications of fluensulfone reduced plant vigor and dry weight of eggplant and tomato, but not cucumber or squash; application of oxamyl had no effect on the vigor or weight of any of the crops. Typically, only the highest rate of fluensulfone was phytotoxic to eggplant and tomato. Tomato was the only crop tested in which there was a reduction in the number of nematodes or galls when fluensulfone or oxamyl was applied to the foliage compared to the

  10. Nematofauna associada à cultura do quiabo na região leste de Minas Gerais The influence of parasitic nematodes on okra crop in eastern Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Rosângela D'Arc de Lima Oliveira

    2007-03-01

    Full Text Available A cultura do quiabo possui importância sócio-cultural para o estado de Minas Gerais (MG e 34,2% do volume de quiabo comercializado na Ceasa/Contagem procede dos municípios localizados entre Caratinga e Governador Valadares. Entretanto, o quiabeiro tem a sua produção influenciada pelos danos decorrentes de infecções causadas pelos nematóides das galhas (Meloidogyne spp.. As principais espécies desse nematóide que atacam o quiabeiro já foram relatadas no Brasil, e algumas destas podem causar a morte da planta. A correta identificação da(s espécie(s e, ou da(s raça(s de Meloidogyne presente(s nas raízes do quiabeiro é importante na escolha da medida de controle mais apropriada. Para determinar a ocorrência e distribuição de Meloidogyne spp. e outros nematóides na região leste de MG, 70 amostras de solo e raízes da cultura, provenientes de 14 localidades, foram avaliadas por características morfológicas e isoenzimáticas. Dentre as populações de Meloidogyne spp. identificadas prevaleceu M. incognita (fenótipos de Esterase I1 e I2, seguida de M. javanica (fenótipos J2 e J3 e M. arenaria (fenótipo A2. A espécie M. mayaguensis foi confirmada pela ocorrência do fenótipo M2 para esterase, N3 para malato desidrogenase, N2 para superóxido dismutase e N3 para glutamato-oxaloacetato transaminase. Este é o primeiro relato da ocorrência de M. mayaguensis em MG. Outros nematóides detectados na rizosfera do quiabeiro foram Aphelenchus sp., Criconemella sp., Helicotylenchus spp., Pratylenchus brachyurus e P. coffeae, Rotylenchulus reniformis, Rotylenchus sp., Tylenchus sp. e Tylenchorhynchus sp.Okra has a cultural and social importance for the State of Minas Gerais (MG, and 34,2% of the volume marketed in the Ceasa/Contagem, MG, come from the municipalities located near Caratinga and Governador Valadares. The okra production is influenced for the infection caused by the root-knot nematodes (Meloidogyne spp.. The main species

  11. Lauric acid in crown daisy root exudate potently regulates root-knot nematode chemotaxis and disrupts Mi-flp-18 expression to block infection.

    Science.gov (United States)

    Dong, Linlin; Li, Xiaolin; Huang, Li; Gao, Ying; Zhong, Lina; Zheng, Yuanyuan; Zuo, Yuanmei

    2014-01-01

    Tomato (Solanum lycopersicum) crops can be severely damaged due to parasitism by the root-knot nematode (RKN) Meloidogyne incognita, but are protected when intercropped with crown daisy (Chrysanthemum coronarium L.). Root exudate may be the determining factor for this protection. An experiment using pots linked by a tube and Petri dish experiments were undertaken to confirm that tomato-crown daisy intercropping root exudate decreased the number of nematodes and alleviated nematode damage, and to determine crown daisy root exudate-regulated nematode chemotaxis. Following a gas chromatography-mass spectrometry assay, it was found that the intercropping protection was derived from the potent bioactivity of a specific root exudate component of crown daisy, namely lauric acid. The Mi-flp-18 gene, encoding an FMRFamide-like peptide neuromodulator, regulated nematode chemotaxis and infection by RNA interference. Moreover, it was shown that lauric acid acts as both a lethal trap and a repellent for M. incognita by specifically regulating Mi-flp-18 expression in a concentration-dependent manner. Low concentrations of lauric acid (0.5-2.0mM) attract M. incognita and consequently cause death, while high concentrations (4.0mM) repel M. incognita. This study elucidates how lauric acid in crown daisy root exudate regulates nematode chemotaxis and disrupts Mi-flp-18 expression to alleviate nematode damage, and presents a general methodology for studying signalling systems affected by plant root exudates in the rhizosphere. This could lead to the development of economical and feasible strategies for controlling plant-parasitic nematodes, and provide an alternative to the use of pesticides in farming systems.

  12. Identification of novel target genes for safer and more specific control of root-knot nematodes from a pan-genome mining.

    Directory of Open Access Journals (Sweden)

    Etienne G J Danchin

    2013-10-01

    Full Text Available Root-knot nematodes are globally the most aggressive and damaging plant-parasitic nematodes. Chemical nematicides have so far constituted the most efficient control measures against these agricultural pests. Because of their toxicity for the environment and danger for human health, these nematicides have now been banned from use. Consequently, new and more specific control means, safe for the environment and human health, are urgently needed to avoid worldwide proliferation of these devastating plant-parasites. Mining the genomes of root-knot nematodes through an evolutionary and comparative genomics approach, we identified and analyzed 15,952 nematode genes conserved in genomes of plant-damaging species but absent from non target genomes of chordates, plants, annelids, insect pollinators and mollusks. Functional annotation of the corresponding proteins revealed a relative abundance of putative transcription factors in this parasite-specific set compared to whole proteomes of root-knot nematodes. This may point to important and specific regulators of genes involved in parasitism. Because these nematodes are known to secrete effector proteins in planta, essential for parasitism, we searched and identified 993 such effector-like proteins absent from non-target species. Aiming at identifying novel targets for the development of future control methods, we biologically tested the effect of inactivation of the corresponding genes through RNA interference. A total of 15 novel effector-like proteins and one putative transcription factor compatible with the design of siRNAs were present as non-redundant genes and had transcriptional support in the model root-knot nematode Meloidogyne incognita. Infestation assays with siRNA-treated M. incognita on tomato plants showed significant and reproducible reduction of the infestation for 12 of the 16 tested genes compared to control nematodes. These 12 novel genes, showing efficient reduction of parasitism when

  13. Social networks of educated nematodes

    Science.gov (United States)

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound...

  14. cyst nematode in tiaret a

    African Journals Online (AJOL)

    F. Labdelli

    1 sept. 2017 ... Syrie par [12], en Arabie saoudite par [16, 17], en Iran par [18] en Inde par [19]en Chine par[20] . .... qui a pour principe d'évaluer le taux de multiplication du nematode en fin de culture et le comparé à ..... cereal cyst nematode complex in relation to breeding resistant durum wheat Fundam. appl. Nemat ...

  15. Role of mungbean root nodule associated fluorescent Pseudomonas and rhizobia in suppressing the root rotting fungi and root knot nematodes in chickpea (Cicer arietinum L.)

    International Nuclear Information System (INIS)

    Noreen, R.; Shafique, A.; Haque, S.E.; Ali, S.A.

    2016-01-01

    Three isolates each of fluorescent Pseudomonas (NAFP-19, NAFP-31 and NAFP-32) and rhizobia (NFB- 103, NFB-107 and NFB-109) which were originally isolated from root nodules of mungbean (Vigna radiata) showed significant biocontrol activity in the screen house and under field condition, against root rotting fungi viz., Macrophomina phaseolina, Fusarium solani, F. oxysporum and Rhizoctonia solani evaluated on chickpea. Biocontrol potential of these isolates was also evaluated against Meloidogyne incognita, the root knot nematode. Application of Pseudomonas and rhizobial isolates as a soil drench, separately or mixed significantly reduced root rot disease under screen house and field conditions. Nematode penetration in roots was also found significantly less in rhizobia or Pseudomonas treatments used separately or mixed as compared to control. Fluorescent Pseudomonas treated plants produced greater number of nodules per plant than control plants and about equal to rhizobia treated plants, indicating that root nodule associated fluorescent Pseudomonas enhance root nodulation. (author)

  16. Efeito de indutores de resistência sobre Meloidogyne exigua do cafeeiro Effect of resistance inducers on Meloidogyne exígua of coffee

    Directory of Open Access Journals (Sweden)

    Sônia Maria de Lima Salgado

    2007-08-01

    Full Text Available A possibilidade de manejo de Meloidogyne exigua Goeldi, 1887, pela ativação de mecanismos de defesa no cafeeiro representa uma alternativa potencialmente útil no manejo desse patógeno. Com este trabalho, objetivou-se avaliar a eclosão e mortalidade de juvenis do segundo estádio (J2 de M. exigua na presença de produtos indutores de resistência e avaliar o efeito do acibenzolar-S-metil (ASM, Bion® na indução de resistência do cafeeiro (Coffea arabica L. 'Catuaí- 144' contra M. exigua. A eclosão e mortalidade do J2 foram avaliadas no ASM e ácido salicílico (AS nas dosagens de 0,2; 0,35 e 0,5 g. i. a./L; e no fosfito de potássio (Hortifós® PK e silicato de potássio (Supa-potássio® nas dosagens 5,0; 7,5 e 10,0 mL/L, empregando água e aldicarbe como testemunhas. No segundo ensaio o ASM (0,2 g i.a./L foi aplicado na quantidade de 125 mL por planta de 'Catuaí-144' com um ano de idade, via pulverização foliar e diretamente ao solo aos 7 dias antes da inoculação e aos 2 e 7 dias após a inoculação de aproximadamente 7000 ovos de M. exigua/planta. Foram utilizadas 8 plantas/tratamento/bloco, totalizando 6 tratamentos (3 épocas de aplicação do ASM, testemunhas absoluta e inoculada, em 4 blocos. Aos 90 dias da inoculação, foi feita a avaliação da população final (número de ovos e juvenis de M. exigua, número de galhas, fator de reprodução (população final/população inicial e peso da matéria fresca da raiz. A dosagem dos produtos não influenciou a eclosão e mortalidade dos J2 de M. exigua. Menor eclosão dos J2 de M. exigua ocorreu igualmente no Supa-potássio® e ácido salicílico, enquanto que a eclosão no ASM e na água foi igual (P The parasitism of coffee roots by Meloidogyne exigua Goeldi, 1887, widespread nematode in the main producing regions, can provoke a series of modifications in the normal development of the plant. The induction of resistance for the activation of existing latent mechanisms of

  17. RNA interference in plant parasitic nematodes

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

    Aug 4, 2008 ... nematodes. RNAi should help identify gene and, hence, protein targets for nematode control strategies. Key words: RNA interference, RNAi, gene expression, plant parasitic nematodes. INTRODUCTION. Plant parasitic nematodes are found as pests of crops throughout the world with many having a severe ...

  18. Meiotic Parthenogenesis in a Root-Knot Nematode Results in Rapid Genomic Homozygosity

    Science.gov (United States)

    Liu, Qingli L.; Thomas, Varghese P.; Williamson, Valerie M.

    2007-01-01

    Many isolates of the plant-parasitic nematode Meloidogyne hapla reproduce by facultative meiotic parthenogenesis. Sexual crosses can occur, but, in the absence of males, the diploid state appears to be restored by reuniting sister chromosomes of a single meiosis. We have crossed inbred strains of M. hapla that differ in DNA markers and produced hybrids and F2 lines. Here we show that heterozygous M. hapla females, upon parthenogenetic reproduction, produce progeny that segregate 1:1 for the presence or absence of dominant DNA markers, as would be expected if sister chromosomes are rejoined, rather than the 3:1 ratio typical of a Mendelian cross. Codominant markers also segregate 1:1 and heterozygotes are present at low frequency (parthenogenesis would be expected to result in rapid genomic homozygosity. This type of high negative crossover interference coupled with positive chromatid interference has not been observed in fungal or other animal systems in which it is possible to examine the sister products of a single meiosis and may indicate that meiotic recombination in this nematode has novel features. PMID:17483427

  19. Phylum-Level Conservation of Regulatory Information in Nematodes despite Extensive Non-coding Sequence Divergence

    Science.gov (United States)

    Gordon, Kacy L.; Arthur, Robert K.; Ruvinsky, Ilya

    2015-01-01

    Gene regulatory information guides development and shapes the course of evolution. To test conservation of gene regulation within the phylum Nematoda, we compared the functions of putative cis-regulatory sequences of four sets of orthologs (unc-47, unc-25, mec-3 and elt-2) from distantly-related nematode species. These species, Caenorhabditis elegans, its congeneric C. briggsae, and three parasitic species Meloidogyne hapla, Brugia malayi, and Trichinella spiralis, represent four of the five major clades in the phylum Nematoda. Despite the great phylogenetic distances sampled and the extensive sequence divergence of nematode genomes, all but one of the regulatory elements we tested are able to drive at least a subset of the expected gene expression patterns. We show that functionally conserved cis-regulatory elements have no more extended sequence similarity to their C. elegans orthologs than would be expected by chance, but they do harbor motifs that are important for proper expression of the C. elegans genes. These motifs are too short to be distinguished from the background level of sequence similarity, and while identical in sequence they are not conserved in orientation or position. Functional tests reveal that some of these motifs contribute to proper expression. Our results suggest that conserved regulatory circuitry can persist despite considerable turnover within cis elements. PMID:26020930

  20. Phylum-Level Conservation of Regulatory Information in Nematodes despite Extensive Non-coding Sequence Divergence.

    Directory of Open Access Journals (Sweden)

    Kacy L Gordon

    2015-05-01

    Full Text Available Gene regulatory information guides development and shapes the course of evolution. To test conservation of gene regulation within the phylum Nematoda, we compared the functions of putative cis-regulatory sequences of four sets of orthologs (unc-47, unc-25, mec-3 and elt-2 from distantly-related nematode species. These species, Caenorhabditis elegans, its congeneric C. briggsae, and three parasitic species Meloidogyne hapla, Brugia malayi, and Trichinella spiralis, represent four of the five major clades in the phylum Nematoda. Despite the great phylogenetic distances sampled and the extensive sequence divergence of nematode genomes, all but one of the regulatory elements we tested are able to drive at least a subset of the expected gene expression patterns. We show that functionally conserved cis-regulatory elements have no more extended sequence similarity to their C. elegans orthologs than would be expected by chance, but they do harbor motifs that are important for proper expression of the C. elegans genes. These motifs are too short to be distinguished from the background level of sequence similarity, and while identical in sequence they are not conserved in orientation or position. Functional tests reveal that some of these motifs contribute to proper expression. Our results suggest that conserved regulatory circuitry can persist despite considerable turnover within cis elements.

  1. Influence of root-knot nematode infestation on antioxidant enzymes, chlorophyll content and growth in Pogostemon cablin (Blanco) Benth.

    Science.gov (United States)

    Bhau, B S; Borah, Bitupon; Ahmed, Reshma; Phukon, P; Gogoi, Barbi; Sarmah, D K; Lal, M; Wann, S B

    2016-04-01

    Plants adapt themselves to overcome adverse environmental conditions, and this involves a plethora of concurrent cellular activities. Physiological experiments or metabolic profiling can quantify this response. Among several diseases of Pogostemon cablin (Blanco) Benth. (Patchouli), root-knot nematode infection caused by Meloidogyne incognita (Kofoid and White) Chitwood causes severe damage to the plant and hence, the oil production. In the present study, we identified M. incognita morphologically and at molecular level using sequenced characterized amplified region marker (SCAR). M. incognita was artificially inoculated at different levels of second stage juveniles (J₂) to examine the effect on Patchouli plant growth parameters. Peroxidase and polyphenol oxidase enzyme activity and changes in the total phenol and chlorophyll contents in M. incognita was also evaluated in response to infection. The results have demonstrated that nematode infestation leads to increased peroxidase activities in the leaves of the patchouli plants and thereby, increase in phenolic content as a means of defence against nematode infestation. Chlorophyll content was also found decreased but no changes in polyphenol oxidase enzyme activity.

  2. Efficacy of organic matter and some bio-inoculants for the management of root-knot nematode infesting tomato

    Directory of Open Access Journals (Sweden)

    Neha Khan

    2015-06-01

    Full Text Available Efficiency of an organic matter like Tagetes erecta and bioinoculants Azotobacter chroococcum and Glomus fasciculatum was investigated in tomato cultivar ‘Pusa Ruby’ when inoculated individually as well as concomitantly for the management of the root-knot nematode, Meloidogyne incognita in terms of growth parameters such as plant length, fresh and dry weights, chlorophyll content, per cent pollen fertility and mycorrhization. Greatest reduction in the numbers of second-stage juveniles in soil, number of root-galls, egg-masses and nematode multiplication was recorded with combined application of T. erecta and bio-inoculants A. chroococcum and G. fasciculatum as compared to untreated control and other treatments. Similarly, the greatest improvement in the plant growth and biomass of tomato was noted in the same treatments. However, individual inoculation of these bio-inoculants and organic fertilizers also showed significant enhancement but was less as compared to combined treatment. A. chroococcum was found most effective against disease incidence followed by G. fasciculatum and T. erecta. Parameters like NP and K contents were significantly enhanced in those plants which received combined treatments of organic matter and bio-inoculants. Azotobacter was found more efficacious against nematodes than Glomus fasciculatum. Organic matter also influenced the activity of bio-inoculants, more with the Azotobacter than G. fasciculatum. DOI: http://dx.doi.org/10.3126/ije.v4i2.12643 International Journal of Environment Vol.4(2 2015: 206-220

  3. The application of Arabidopsis thaliana in studying tripartite interactions among plants, beneficial fungal endophytes and biotrophic plant-parasitic nematodes.

    Science.gov (United States)

    Martinuz, Alfonso; Zewdu, Getaneh; Ludwig, Nicole; Grundler, Florian; Sikora, Richard A; Schouten, Alexander

    2015-04-01

    The research demonstrated that Arabidopsis can be used as a model system for studying plant-nematode-endophyte tripartite interactions; thus, opening new possibilities for further characterizing the molecular mechanisms behind these interactions. Arabidopsis has been established as an important model system for studying plant biology and plant-microbe interactions. We show that this plant can also be used for studying the tripartite interactions among plants, the root-knot nematode Meloidogyne incognita and a beneficial endophytic isolate of Fusarium oxysporum, strain Fo162. In various plant species, Fo162 can systemically reduce M. incognita infection development and fecundity. Here it is shown that Fo162 can also colonize A. thaliana roots without causing disease symptoms, thus behaving as a typical endophyte. As observed for other plants, this endophyte could not migrate from the roots into the shoots and leaves. Direct inoculation of the leaves also did not result in colonization of the plant. A significant increase in plant fresh weight, root length and average root diameter was observed, suggesting the promotion of plant growth by the endophyte. The inoculation of A. thaliana with F. oxysporum strain Fo162 also resulted in a significant reduction in the number of M. incognita juveniles infecting the roots and ultimately the number of galls produced. This was also observed in a split-root experiment, in which the endophyte and nematode were spatially separated. The usefulness of Arabidopsis opens new possibilities for further dissecting complex tripartite interactions at the molecular and biochemical level.

  4. Host Delivered RNAi of Two Cuticle Collagen Genes, Mi-col-1 and Lemmi-5 Hampers Structure and Fecundity in Meloidogyne incognita

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    Sagar Banerjee

    2018-01-01

    Full Text Available Root-knot nematodes have emerged as devastating parasites causing substantial losses to agricultural economy worldwide. Tomato is the most favored host for major species of root-knot nematodes. Control strategies like use of nematicides have proved to be harmful to the environment. Other control methods like development of resistant cultivars and crop rotation have serious limitations. This study deals with the application of host generated RNA interference toward development of resistance against root-knot nematode Meloidogyne incognita in tomato. Two cuticle collagen genes viz. Mi-col-1 and Lemmi-5 involved in the synthesis and maintenance of the cuticle in M. incognita were targeted through host generated RNA interference. Expression of both Mi-col-1 and Lemmi-5 was found to be higher in adult females followed by egg masses and J2s. Tomato var. Pusa Ruby was transformed with the RNAi constructs of these genes to develop transgenic lines expressing the target dsRNAs. 30.80–35.00% reduction in the number of adult females, 50.06–65.73% reduction in the number of egg mass per plant and 76.47–82.59% reduction in the number of eggs per egg mass were observed for the T1 events expressing Mi-col-1 dsRNA. Similarly, 34.14–38.54% reduction in the number of adult females, 62.34–66.71% reduction in number of egg mass per plant and 67.13–79.76% reduction in the number of eggs per egg mass were observed for the T1 generation expressing Lemmi-5 dsRNA. The multiplication factor of M. incognita reduced significantly in both the cases and the structure of adult females isolated from transgenic plants were heavily distorted. This study demonstrates the role of the cuticle collagen genes Mi-col-1 and Lemmi-5 in the structure and development of M. incognita cuticle inside the host and reinforces the potential of host generated RNA interference for management of plant parasitic nematodes (PPNs.

  5. Complete genome sequence of Bacillus thuringiensis YC-10, a novel active strain against plant-parasitic nematodes.

    Science.gov (United States)

    Cheng, Feixue; Wang, Jian; Song, Zhiqiang; Cheng, Ju'e; Zhang, Deyong; Liu, Yong

    2015-09-20

    Bacillus thuringiensis is an important microbial biopesticide for controlling agricultural pests by the production of toxic parasporal crystals proteins.Here,we report the finished annotated genome sequence of B. thuringiensis YC-10,which is highly toxic to nematodes.The complete genome sequence consists of a circular chromosome and nine circular plasmids,which the biggest plasmid harbors six parasporal crystals proteins genes consisting of cry1Aa, cry1Ac, cry1Ia, cry2Aa, cry2Ab and cryB1. The crystals proteins of Cry1Ia and Cry1Aa have high nematicidal activity against Meloidogyne incognita. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Efeito de isolados de Paecilomyces lilacinus no desenvolvimento de cafezais e na população de Meloidogyne paranaensis Effect of isolates of Paecilomyces lilacinus on the development of coffee plantations and on the population of Meloidogyne paranaensis

    Directory of Open Access Journals (Sweden)

    Marina Capparelli Cadioli

    2009-06-01

    Full Text Available Com a finalidade de diminuir as perdas causadas pelos nematóides do gênero Meloidogyne (Goeldi, 1887 na cultura do cafeeiro, dentre as diversas medidas de manejo, o controle biológico com o fungo Paecilomyces lilacinus (Thom., 1910 Samson, 1974 se destaca como uma alternativa de controle vantajosa, quer dos pontos de vista ecológico ou econômico. Assim, neste trabalho, objetivou-se avaliar a eficiência de 10 isolados de Paecilomyces lilacinus no controle de Meloidogyne paranaensis em cafeeiro (Coffea arabica L. cv. Icatú, em casa-de-vegetação. No experimento I, as mudas de cafeeiro foram transplantadas em solo onde foram, anteriormente, cultivados tomateiros para multiplicação de M. paranaensis mais 50 g de arroz colonizado com os 10 isolados. No segundo experimento, mudas de cafeeiro foram transplantadas para substrato solo e areia (1:1 juntamente com 50 g de arroz colonizado com os isolados. Em seguida, as mudas foram inoculadas com ± 5000 ovos de M. paranaensis. Nos dois experimentos, após 15 dias procedeu-se aplicação por cobertura de 50 g dos isolados. O delineamento foi inteiramente casualizado com 12 tratamentos. Após 90 dias, foram feitas as avaliações. Os isolados de P. lilacinus não afetaram o diâmetro do caule de cafeeiro. No experimento I, os isolados Pae 22, 24 e 28 promoveram o crescimento dos cafeeiros; todos os isolados reduziram a população de ovos no sistema radicular; e os isolados Pae 3 e 12 reduziram a população de J2 de M. paranaensis no solo. No experimento II, os isolados Pae 03, 10, 12 e 13 favoreceram o crescimento das plantas, mas reduziram o peso fresco do sistema radicular; todos os isolados reduziram a população de J2 no solo; e os isolados Pae 3, 10, 13, 18, 22 e 24 reduziram as malformações causadas por M. paranaensis nas raízes.In order to reduce the losses caused by nematodes of the genus Meloidogyne (Goeldi, 1887 in coffee plantation, among several management measures, biological

  7. A novel Meloidogyne graminicola effector, MgMO237, interacts with multiple host defence-related proteins to manipulate plant basal immunity and promote parasitism.

    Science.gov (United States)

    Chen, Jiansong; Hu, Lili; Sun, Longhua; Lin, Borong; Huang, Kun; Zhuo, Kan; Liao, Jinling

    2018-02-27

    Plant-parasitic nematodes can secrete effector proteins into the host tissue to facilitate their parasitism. In this study, we report a novel effector protein, MgMO237, from Meloidogyne graminicola, which is exclusively expressed within the dorsal oesophageal gland cell and markedly up-regulated in parasitic third-/fourth-stage juveniles of M. graminicola. Transient expression of MgMO237 in protoplasts from rice roots showed that MgMO237 was localized in the cytoplasm and nucleus of the host cells. Rice plants overexpressing MgMO237 showed an increased susceptibility to M. graminicola. In contrast, rice plants expressing RNA interference vectors targeting MgMO237 showed an increased resistance to M. graminicola. In addition, yeast two-hybrid and co-immunoprecipitation assays showed that MgMO237 interacted specifically with three rice endogenous proteins, i.e. 1,3-β-glucan synthase component (OsGSC), cysteine-rich repeat secretory protein 55 (OsCRRSP55) and pathogenesis-related BetvI family protein (OsBetvI), which are all related to host defences. Moreover, MgMO237 can suppress host defence responses, including the expression of host defence-related genes, cell wall callose deposition and the burst of reactive oxygen species. These results demonstrate that the effector MgMO237 probably promotes the parasitism of M. graminicola by interacting with multiple host defence-related proteins and suppressing plant basal immunity in the later parasitic stages of nematodes. © 2018 BSPP AND JOHN WILEY & SONS LTD.

  8. A genome-wide association study of a global rice panel reveals resistance in Oryza sativa to root-knot nematodes

    Science.gov (United States)

    Dimkpa, Stanley O. N.; Lahari, Zobaida; Shrestha, Roshi; Douglas, Alex; Gheysen, Godelieve; Price, Adam H.

    2016-01-01

    The root-knot nematode Meloidogyne graminicola is one of the most serious nematode pests worldwide and represents a major constraint on rice production. While variation in the susceptibility of Asian rice (Oryza sativa) exists, so far no strong and reliable resistance has been reported. Quantitative trait loci for partial resistance have been reported but no underlying genes have been tagged or cloned. Here, 332 accessions of the Rice Diversity Panel 1 were assessed for gall formation, revealing large variation across all subpopulations of rice and higher susceptibility in temperate japonica accessions. Accessions Khao Pahk Maw and LD 24 appeared to be resistant, which was confirmed in large pot experiments where no galls were observed. Detailed observations on these two accessions revealed no nematodes inside the roots 2 days after inoculation and very few females after 17 days (5 in Khao Pahk Maw and 100 in the susceptible controls). These two cultivars appear ideal donors for breeding root-knot nematode resistance. A genome-wide association study revealed 11 quantitative trait loci, two of which are close to epistatic loci detected in the Bala x Azucena population. The discussion highlights a small number of candidate genes worth exploring further, in particular many genes with lectin domains and genes on chromosome 11 with homology to the Hordeum Mla locus. PMID:26552884

  9. Linhagens de alface-crespa para o verão resistentes ao Meloidogyne javanica e ao vírus mosaico-da-alface Lineages of crisp-leaf lettuce for summer cropping resistant to Meloidogyne javanica and to Lettuce mosaic virus

    Directory of Open Access Journals (Sweden)

    Renata Rodrigues Silva

    2008-10-01

    Full Text Available O objetivo deste trabalho foi selecionar famílias F4 de alface, oriundas do cruzamento entre as cultivares Verônica e Salinas 88, para o cultivo no verão, com relação ao tipo de folha, e à resistência ao Lettuce mosaic virus (LMV e ao nematóide-das-galhas Meloidogyne javanica. Primeiramente, avaliaram-se a coloração da folha, tipos de borda e limbo foliares, além da tolerância ao calor no campo, em blocos ao acaso compostos pelas 15 famílias F4 previamente selecionadas, pelas cultivares parentais e pela cultivar testemunha Regina 71 (folhas lisas e tolerante ao calor, com cinco repetições e oito plantas por parcela. Na segunda etapa, as famílias foram avaliadas quanto à resistência ao LMV e ao nematóide-das-galhas, em bandejas de 128 células acondicionadas em estufa. As médias das notas atribuídas a cada família foram comparadas às médias de cada cultivar parental pelo teste de Dunnet (5%. A família AFX007B-140-21, homozigota resistente aos nematóides e ao LMV e, também, tolerante ao calor, foi a mais promissora. O cruzamento entre uma cultivar de folhas crespas e soltas com uma de folhas crespas e repolhuda, pode originar linhagens promissoras tanto de folhas crespas quanto de folhas lisas.The aim of this work was to select F4 lettuce families, derived from the cross 'Veronica' x 'Salinas 88 ', for summer cropping, type of leaves, and for resistance to Meloidogyne javanica and to Lettuce mosaic virus (LMV. First, evaluations were made for leaf colour, leaf limb, border type, and heat tolerance in the field, in a complete blocks desing, in 15 F4 families previously selected, parent cultivars and, as control, the cultivar Regina 71 (butterleaf and tolerant to heat. Five replicates and eight plants per plot were used. As second step, the families were evaluated in greenhouse, in 128-cell expanded polystyrene trays, for resistance to LMV and root-knot nematodes. Score means of each family were compared to the means of

  10. Behavioral differences of Heterodera glycines and Meloidogyne incognita infective juveniles exposed to root extracts in vitro

    Science.gov (United States)

    The in vitro behaviors of infective juveniles (J2) of Heterodera glycines and Meloidogyne incognita were compared in the presence and absence of plant root extracts. In an agar plate attraction-retention assay, H. glycines was 15-fold more responsive to a chemical attractant (CaCl2; P < 0.05) than w...

  11. Relative susceptibilities of five fodder radish varieties (Raphanus sativus var. Oleiformis) to Meloidogyne chitwoodi

    NARCIS (Netherlands)

    Teklu, M.G.; Schomaker, C.H.; Been, T.H.

    2014-01-01

    The fodder radish varieties Anaconda, Contra, Defender, Doublet and Terranova, known to have some partial resistance, were compared to the standard variety, Radical, to estimate their relative susceptibility (RS) for both population dynamic parameters of Meloidogyne chitwoodi and to evaluate Pi

  12. Resistência do cafeeiro a nematóides: I - Testes em progênies e híbridos, para Meloidogyne exigua Coffee breeding for resistance to Meloidogyne exigua: I - Screening test using arabica progenies and interespecific hybrids

    Directory of Open Access Journals (Sweden)

    L. C. Fazuoli

    1977-01-01

    Full Text Available Procurou-se identificar fontes de resistência ao nematóide Meloidogyne exígua em cafeeiros derivados de híbridos interespecíficos e em progênies de café arábica oriundas da Etiópia, em experimentos estabelecidos em duas localidades. A infestação foi feita por dois processos usados com freqüência nesse tipo de trabalho. As avaliações do grau de ataque foram feitas quatro e 12 meses após a infestação, em Campinas e Ribeirão Preto, respectivamente, adotando-se escala variando de zero, para ausência de galhas, a cinco pontos para grande intensidade de ataque. Verificou-se que a leitura feita aos quatro meses é tão eficiente quanto aos 12 meses, indicando a possibilidade de abreviar consideravelmente a duração dessas avaliações. Notou-se, no experimento de Ribeirão Preto, uma redução de aproximadamente 8% no crescimento das mudas infestadas e verificou-se, também, uma redução de 11,5% e 12% nos pesos verde e seco das plantas, devido ao ataque do nematóide. De 1.692 plantas examinadas nos dois experimentos, selecionaram-se 106 (6,3%, caracterizadas pela ausência de galhas. As populações derivadas dos híbridos entre Coffea arabica e C. canephora revelaram-se mais promissoras, contribuindo com maior número de plantas resistentes. As plantas do experimento instalado em Campinas foram inoculadas também com a raça II de Hemileia vastatrix para o estudo da resistência conjunta aos dois patógenos. Essas seleções, em número de 38, representam valioso material para o programa de melhoramento do cafeeiro.Two coffee screening tests were undertaken in order to find out sources of resistance to the nematode M. exigua. Arabica progenies from Ethiopia origin and advanced popu-lations derived from interspecific crosses (Coffea arabica x C. canephora and C. arabica x C. dewevrei were evaluated. A five point scale (0 point to the roots without galls and 5 points to severely attacked roots was used for determination of the

  13. Susceptibilidad de genotipos de Solanum spp. al nematodo causante del nudo radical Meloidogyne spp. (chitwood

    Directory of Open Access Journals (Sweden)

    Cristian Gelpud Chaves

    2011-01-01

    Full Text Available El cultivo del lulo (Solanum quitoense L. presenta una disminución en su productividad, debido al ataque de patógenos como el nematodo del nudo radical Meloidogyne spp., en el Departamento de Nariño (Colombia, se han reportado incidencias cercanas al 79%, y pérdidas del 50%. En la presente investigación, se colectaron 45 genotipos de (Solanum quitoense L. en los Departamentos de Nariño y Putumayo y 4 genotipos silvestres (S. mammosum, S. hirtum, S. marginatum y S. umbellatum buscando fuentes de resistencia al nematodo. Se inocularon 9 plantas de cada genotipo de dos meses de edad con 10000 huevos de Meloidogyne spp., dejando tres testigos por cada material. Las variables evaluadas fueron: altura de planta, severidad, incidencia, peso fresco (tallo y raíz y especies prevalentes de Meloidogyne spp. Se hizo una clasificación de genotipos mediante escala de resistencia y regresión entre la severidad y las demás variables para establecer el efecto de Meloidogyne spp. sobre los genotipos de planta. Los resultados mostraron 100% de incidencia del nematodo en todos los genotipos, 2.04% genotipos resistentes, 34.7% moderadamente resistentes, 42.8% moderadamente susceptibles, 18.3% susceptibles, y 2.04% altamente susceptibles. El genotipo SQbr05 resistente, no se vio afectado por la severidad, al contrario SQbc04 genotipo susceptible, mostró reducciones significativas en peso fresco de tallo y raíz, (R² = 0.71 y 0.98, el genotipo silvestre (S. mammosum es altamente susceptible, Meloidogyne incognita presentó 55.31% de presencia. El genotipo SQbr05 es promisorio para ser evaluado en campo.

  14. Estudo de métodos de infestação para avaliação precoce da resistência do cafeeiro a Meloidogyne exigua Evaluation of four screening methods for resistance to Meloidogyne exigua in coffee seedlings

    Directory of Open Access Journals (Sweden)

    L. C Fazuoli

    1977-01-01

    Full Text Available Procurou-se desenvolver um método para avaliar a resistência de mudas novas de cafeeiros ao nematóide Meloidogyne exigua. Dois experimentos foram realizados, a fim de testar a eficiência de quatro métodos de infestação, em mudas do cultivar mundo novo de Coffea arabica, utilizando-se areia como substrato, em caixas de plástico. A avaliação do ataque pelo nematóide foi realizada subjetivamente, dando-se um ponto na ausência de galhas e cinco pontos na presença de elevado número de galhas nas raízes do cafeeiro. Com base nos parâmetros estudados, verificou-se que 60 dias após a germinação das sementes, o sistema de infestação mais eficiente consistiu na colocação de pequenos pedaços de raízes de cafeeiro com galhas, misturados com o substrato das caixas de germinação, juntamente com uma suspensão em água, de ovos e larvas do nematóide. Em leitura efetuada 150 dias após a germinação, não se verificou diferença significativa entre a infestação provocada através do uso de pequenos pedaços de raízes e com a suspensão contendo ovos e larvas ou a associação de ambos os métodos de infestação. Em todos estes tratamentos notou-se que as raízes dos cafeeiros possuíam elevado número de galhas. Os dados obtidos indicam a possibilidade de realizar testes precoces de resistência ao nematóide M. exigua, o que é de particular interesse no plano geral de melhoramento visando resistência a esse parasita.Four methods of infestation namely: a sand infestation with small pieces of root-knots; b irrigation of sand with nematode eggs and larvae; c the combination of a and b, and d soil infested plus sand, were compared to develop a screening method for the evaluation of resistance of coffee seedlings to Meloidogyne exigua. Seedlings of Mundo Novo cultivar belonging to the Coffea arabica species were obtained by sowing seeds in plastic trays containing sand. A five point scale was used to determine the intensity of the

  15. Bacterial antagonists of fungal pathogens also control root-knot nematodes by induced systemic resistance of tomato plants.

    Science.gov (United States)

    Adam, Mohamed; Heuer, Holger; Hallmann, Johannes

    2014-01-01

    The potential of bacterial antagonists of fungal pathogens to control the root-knot nematode Meloidogyne incognita was investigated under greenhouse conditions. Treatment of tomato seeds with several strains significantly reduced the numbers of galls and egg masses compared with the untreated control. Best performed Bacillus subtilis isolates Sb4-23, Mc5-Re2, and Mc2-Re2, which were further studied for their mode of action with regard to direct effects by bacterial metabolites or repellents, and plant mediated effects. Drenching of soil with culture supernatants significantly reduced the number of egg masses produced by M. incognita on tomato by up to 62% compared to the control without culture supernatant. Repellence of juveniles by the antagonists was shown in a linked twin-pot set-up, where a majority of juveniles penetrated roots on the side without inoculated antagonists. All tested biocontrol strains induced systemic resistance against M. incognita in tomato, as revealed in a split-root system where the bacteria and the nematodes were inoculated at spatially separated roots of the same plant. This reduced the production of egg masses by up to 51%, while inoculation of bacteria and nematodes in the same pot had only a minor additive effect on suppression of M. incognita compared to induced systemic resistance alone. Therefore, the plant mediated effect was the major reason for antagonism rather than direct mechanisms. In conclusion, the bacteria known for their antagonistic potential against fungal pathogens also suppressed M. incognita. Such "multi-purpose" bacteria might provide new options for control strategies, especially with respect to nematode-fungus disease complexes that cause synergistic yield losses.

  16. Transcription profile of soybean-root-knot nematode interaction reveals a key role of phythormones in the resistance reaction.

    Science.gov (United States)

    Beneventi, Magda Aparecida; da Silva, Orzenil Bonfim; de Sá, Maria Eugênia Lisei; Firmino, Alexandre Augusto Pereira; de Amorim, Regina Maria Santos; Albuquerque, Erika Valéria Saliba; da Silva, Maria Cristina Mattar; da Silva, Joseane Padilha; Campos, Magnólia de Araújo; Lopes, Marcus José Conceição; Togawa, Roberto Coiti; Pappas, Georgios Joanis; Grossi-de-Sa, Maria Fatima

    2013-05-10

    Root-knot nematodes (RKN- Meloidogyne genus) present extensive challenges to soybean crop. The soybean line (PI 595099) is known to be resistant against specific strains and races of nematode species, thus its differential gene expression analysis can lead to a comprehensive gene expression profiling in the incompatible soybean-RKN interaction. Even though many disease resistance genes have been studied, little has been reported about phytohormone crosstalk on modulation of ROS signaling during soybean-RKN interaction. Using 454 technology to explore the common aspects of resistance reaction during both parasitism and resistance phases it was verified that hormone, carbohydrate metabolism and stress related genes were consistently expressed at high levels in infected roots as compared to mock control. Most noteworthy genes include those encoding glycosyltransferases, peroxidases, auxin-responsive proteins and gibberellin-regulated genes. Our data analysis suggests the key role of glycosyltransferases, auxins and components of gibberellin signal transduction, biosynthesis and deactivation pathways in the resistance reaction and their participation in jasmonate signaling and redox homeostasis in mediating aspects of plant growth and responses to biotic stress. Based on this study we suggest a reasonable model regarding to the complex mechanisms of crosstalk between plant hormones, mainly gibberellins and auxins, which can be crucial to modulate the levels of ROS in the resistance reaction to nematode invasion. The model also includes recent findings concerning to the participation of DELLA-like proteins and ROS signaling controlling plant immune or stress responses. Furthermore, this study provides a dataset of potential candidate genes involved in both nematode parasitism and resistance, which can be tested further for their role in this biological process using functional genomics approaches.

  17. A Nematode Calreticulin, Rs-CRT, Is a Key Effector in Reproduction and Pathogenicity of Radopholus similis

    Science.gov (United States)

    Li, Yu; Wang, Ke; Xie, Hui; Wang, Yan-Tao; Wang, Dong-Wei; Xu, Chun-Lin; Huang, Xin; Wang, De-Sen

    2015-01-01

    Radopholus similis is a migratory plant-parasitic nematode that causes severe damage to many agricultural and horticultural crops. Calreticulin (CRT) is a Ca2+-binding multifunctional protein that plays key roles in the parasitism, immune evasion, reproduction and pathogenesis of many animal parasites and plant nematodes. Therefore, CRT is a promising target for controlling R. similis. In this study, we obtained the full-length sequence of the CRT gene from R. similis (Rs-crt), which is 1,527-bp long and includes a 1,206-bp ORF that encodes 401 amino acids. Rs-CRT and Mi-CRT from Meloidogyne incognita showed the highest similarity and were grouped on the same branch of the phylogenetic tree. Rs-crt is a multi-copy gene that is expressed in the oesophageal glands and gonads of females, the gonads of males, the intestines of juveniles and the eggs of R. similis. The highest Rs-crt expression was detected in females, followed by juveniles, eggs and males. The reproductive capability and pathogenicity of R. similis were significantly reduced after treatment with Rs-crt dsRNA for 36 h. Using plant-mediated RNAi, we confirmed that Rs-crt expression was significantly inhibited in the nematodes, and resistance to R. similis was significantly improved in transgenic tomato plants. Plant-mediated RNAi-induced silencing of Rs-crt could be effectively transmitted to the F2 generation of R. similis; however, the silencing effect of Rs-crt induced by in vitro RNAi was no longer detectable in F1 and F2 nematodes. Thus, Rs-crt is essential for the reproduction and pathogenicity of R. similis. PMID:26061142

  18. Inconsistency of the biological control of Meloidogyne incognita race 2 in melon by endophytic bacteria Inconsistência do controle biológico de Meloidogyne incognita raça 2 em meloeiro por bactérias endofíticas

    Directory of Open Access Journals (Sweden)

    Jeane E de Medeiros

    2009-09-01

    Full Text Available We obtained 61 rhizobacterium isolates from rhizosphere soil samples collected in melon commercial fields located in Mossoró, Rio Grande do Norte State, Brazil. These isolates, along with 56 endophytic bacteria from the Collection of Cultures of the Plant Bacteriology Laboratory of the Universidade Federal Rural de Pernambuco, were tested for controlling Meloidogyne incognita race 2 in melon. To infest the soil with nematodes, 1000 eggs of Meloidogyne incognita race 2 per plant were placed in pots where seedlings of the yellow-type melon, cultivar AF 682, were growing for 10 days. Two days before, 20 mL of bacterial suspension (0.7 OD570nm were poured into each pot. After 60 days, fresh root biomass, gall index, egg mass, and the nematode reproduction factor were assessed. Among the 117 isolates screened, the endophytic Bacillus ENM7, ENM10, and ENM51 were selected because they significantly reduced egg mass and/or gall index. However, when tested again, separately and in mixtures, these isolates nor confirmed their efficiency in vivo, neither affected juvenile emergence in vitro. These results give evidence on the inconsistency of using endophytic-bacteria in the control of M. incognita race 2 in melon.A partir de amostras de solo coletadas em plantios comerciais de meloeiro, situados em Mossoró-RN, foram obtidos 61 isolados de rizobactérias que, juntamente com outros 56 isolados endofíticos pertencentes à Coleção de Culturas do Laboratório de Fitobacteriologia da Universidade Federal Rural de Pernambuco, foram avaliados para o controle de Meloidogyne incognita raça 2 em melão. Plantas de meloeiro Amarelo, cultivar AF 682, com dez dias de idade tiveram o solo infestado com 1000 ovos de M. incognita raça 2 por planta. Dois dias antes, foram depositados em cada vaso 20 mL da suspensão bacteriana (DO570nm = 0,7. Decorridos 60 dias, foram determinados a biomassa fresca das raízes, os índices de galhas e de massa de ovos e o fator de

  19. Predator-prey interactions of nematode-trapping fungi and nematodes: both sides of the coin.

    Science.gov (United States)

    Vidal-Diez de Ulzurrun, Guillermo; Hsueh, Yen-Ping

    2018-05-01

    Nematode-trapping fungi develop complex trapping devices to capture and consume nematodes. The dynamics of these organisms is especially important given the pathogenicity of nematodes and, consequently, the potential application of nematode-trapping fungi as biocontrol agents. Furthermore, both the nematodes and nematode-trapping fungi can be easily grown in laboratories, making them a unique manipulatable predator-prey system to study their coevolution. Several different aspects of these fungi have been studied, such as their genetics and the different factors triggering trap formation. In this review, we use the nematode-trapping fungus Arthrobotrys oligospora (which forms adhesive nets) as a model to describe the trapping process. We divide this process into several stages; namely attraction, recognition, trap formation, adhesion, penetration, and digestion. We summarize the latest findings in the field and current knowledge on the interactions between nematodes and nematode-trapping fungi, representing both sides of the predator-prey interaction.

  20. Nematode Indicators of Organic Enrichment

    NARCIS (Netherlands)

    Ferris, H.; Bongers, A.M.T.

    2006-01-01

    The organisms of the soil food web, dependent on resources from plants or on amendment from other sources, respond characteristically to enrichment of their environment by organic matter. Primary consumers of the incoming substrate, including bacteria, fungi, plant-feeding nematodes, annelids, and

  1. Colored Mulches Affect Yield of Fresh-market Tomato Infected with Meloidogyne incognita

    OpenAIRE

    Fortnum, B. A.; Decoteau, D. R.; Kasperbauer, M. J.

    1997-01-01

    The effects of different-colored polyethylene mulches on the quantity and spectra of reflected light, earliness of fruit set, fruit yield and quality, and root-knot disease were studied in field-grown, staked tomato (Lycopersicon esculentum). White mulch reflected more photosynthetic light and a lower far-red-to-red ratio than red mulch, whereas black mulch reflected less than 5 percent of any color. Soil temperatures and fruit yields were recorded for tomato plants inoculated with Meloidogyn...

  2. Sewage sludge amendment and inoculation with plant-parasitic nematodes do not facilitate the internalization of Salmonella Typhimurium LT2 in lettuce plants.

    Science.gov (United States)

    Fornefeld, Eva; Baklawa, Mohamed; Hallmann, Johannes; Schikora, Adam; Smalla, Kornelia

    2018-05-01

    Contamination of fruits and vegetables with Salmonella is a serious threat to human health. In order to prevent possible contaminations of fresh produce it is necessary to identify the contributing ecological factors. In this study we investigated whether the addition of sewage sludge or the presence of plant-parasitic nematodes foster the internalization of Salmonella enterica serovar Typhimurium LT2 into lettuce plants, posing a potential threat for human health. Greenhouse experiments were conducted to investigate whether the amendment of sewage sludge to soil or the presence of plant-parasitic nematodes Meloidogyne hapla or Pratylenchus crenatus promote the internalization of S. Typhimurium LT2 from soil into the edible part of lettuce plants. Unexpectedly, numbers of cultivable S. Typhimurium LT2 decreased faster in soil with sewage sludge than in control soil but not in root samples. Denaturing gradient gel electrophoresis analysis revealed shifts of the soil bacterial communities in response to sewage sludge amendment and time. Infection and proliferation of nematodes inside plant roots were observed but did not influence the number of cultivable S. Typhimurium LT2 in the root samples or in soil. S. Typhimurium LT2 was not detected in the leaf samples 21 and 49 days after inoculation. The results indicate that addition of sewage sludge, M. hapla or P. crenatus to soil inoculated with S. Typhimurium LT2 did not result in an improved survival in soil or internalization of lettuce plants. Copyright © 2017. Published by Elsevier Ltd.

  3. A major QTL corresponding to the Rk locus for resistance to root-knot nematodes in cowpea (Vigna unguiculata L. Walp.).

    Science.gov (United States)

    Huynh, Bao-Lam; Matthews, William C; Ehlers, Jeffrey D; Lucas, Mitchell R; Santos, Jansen R P; Ndeve, Arsenio; Close, Timothy J; Roberts, Philip A

    2016-01-01

    Genome resolution of a major QTL associated with the Rk locus in cowpea for resistance to root-knot nematodes has significance for plant breeding programs and R gene characterization. Cowpea (Vigna unguiculata L. Walp.) is a susceptible host of root-knot nematodes (Meloidogyne spp.) (RKN), major plant-parasitic pests in global agriculture. To date, breeding for host resistance in cowpea has relied on phenotypic selection which requires time-consuming and expensive controlled infection assays. To facilitate marker-based selection, we aimed to identify and map quantitative trait loci (QTL) conferring the resistance trait. One recombinant inbred line (RIL) and two F2:3 populations, each derived from a cross between a susceptible and a resistant parent, were genotyped with genome-wide single nucleotide polymorphism (SNP) markers. The populations were screened in the field for root-galling symptoms and/or under growth-chamber conditions for nematode reproduction levels using M. incognita and M. javanica biotypes. One major QTL was mapped consistently on linkage group VuLG11 of each population. By genotyping additional cowpea lines and near-isogenic lines derived from conventional backcrossing, we confirmed that the detected QTL co-localized with the genome region associated with the Rk locus for RKN resistance that has been used in conventional breeding for many decades. This chromosomal location defined with flanking markers will be a valuable target in marker-assisted breeding and for positional cloning of genes controlling RKN resistance.

  4. Deteksi dan Identifikasi Spesies Meloidogyne pada Tanaman Wortel dari Dataran Tinggi Malino, Gowa, Sulawesi Selatan

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    Hishar Mirsam

    2015-02-01

    Full Text Available Meloidogyne spp. was reported as the cause of branched tuber disease on several carrot production areas in Java, Indonesia and may potentially cause yield loss. This research aimed to use morphological and molecular characters to detect and identify Meloidogyne species on carrot from Malino Highland, Sub-district of Tinggimoncong, District of Gowa, South Sulawesi. Morphological identification was done based on character of the female perineal pattern. Molecular identification was based on amplification of r-DNA by polymerase chain reaction technique using species specific primers (Fjav/Rjav for M. javanica, Far/Rar for M. arenaria, and Finc/Rinc for M. incognita and multiplex primer (JMV1/JMVhapla/JMV2 for M. hapla, M. chitwoodi, and M. fallax.Two of Meloidogyne species, i.e. M. incognita and M. arenaria were detected associated with the incidence of carrot branched tuber. The specific primers amplified two DNA bands, i.e. ± 999 bp of M. incognita and ± 420 bp of M. arenaria, while multiplex primer was failed to amplify DNA bands. Nucleotide sequence analysis showed M. incognita isolate of Malino was closely related to M. incognita isolate from Bangka-Indonesia, China (isolate JS2, and Malaysia (isolates JIK4, FIK4, JIT19, and FIT19 with homology of 99.2–100.0%. The nucleotide sequences of M. arenaria from Malino was submitted to GenBank with accession number KP234264, which was the first nucleotide sequence data in GenBank.

  5. Anatomical Alterations in Plant Tissues Induced by Plant-Parasitic Nematodes

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    Juan E. Palomares-Rius

    2017-11-01

    Full Text Available Plant-parasitic nematodes (PPNs interact with plants in different ways, for example, through subtle feeding behavior, migrating destructively through infected tissues, or acting as virus-vectors for nepoviruses. They are all obligate biotrophic parasites as they derive their nutrients from living cells which they modify using pharyngeal gland secretions prior to food ingestion. Some of them can also shield themselves against plant defenses to sustain a relatively long lasting interaction while feeding. This paper is centered on cell types or organs that are newly induced in plants during PPN parasitism, including recent approaches to their study based on molecular biology combined with cell biology-histopathology. This issue has already been reviewed extensively for major PPNs (i.e., root-knot or cyst nematodes, but not for other genera (viz. Nacobbus aberrans, Rotylenchulus spp.. PPNs have evolved with plants and this co-evolution process has allowed the induction of new types of plant cells necessary for their parasitism. There are four basic types of feeding cells: (i non-hypertrophied nurse cells; (ii single giant cells; (iii syncytia; and (iv coenocytes. Variations in the structure of these cells within each group are also present between some genera depending on the nematode species viz. Meloidogyne or Rotylenchulus. This variability of feeding sites may be related in some way to PPN life style (migratory ectoparasites, sedentary ectoparasites, migratory ecto-endoparasites, migratory endoparasites, or sedentary endoparasites. Apart from their co-evolution with plants, the response of plant cells and roots are closely related to feeding behavior, the anatomy of the nematode (mainly stylet size, which could reach different types of cells in the plant, and the secretory fluids produced in the pharyngeal glands. These secretory fluids are injected through the stylet into perforated cells where they modify plant cytoplasm prior to food removal

  6. Anatomical Alterations in Plant Tissues Induced by Plant-Parasitic Nematodes

    Science.gov (United States)

    Palomares-Rius, Juan E.; Escobar, Carolina; Cabrera, Javier; Vovlas, Alessio; Castillo, Pablo

    2017-01-01

    Plant-parasitic nematodes (PPNs) interact with plants in different ways, for example, through subtle feeding behavior, migrating destructively through infected tissues, or acting as virus-vectors for nepoviruses. They are all obligate biotrophic parasites as they derive their nutrients from living cells which they modify using pharyngeal gland secretions prior to food ingestion. Some of them can also shield themselves against plant defenses to sustain a relatively long lasting interaction while feeding. This paper is centered on cell types or organs that are newly induced in plants during PPN parasitism, including recent approaches to their study based on molecular biology combined with cell biology-histopathology. This issue has already been reviewed extensively for major PPNs (i.e., root-knot or cyst nematodes), but not for other genera (viz. Nacobbus aberrans, Rotylenchulus spp.). PPNs have evolved with plants and this co-evolution process has allowed the induction of new types of plant cells necessary for their parasitism. There are four basic types of feeding cells: (i) non-hypertrophied nurse cells; (ii) single giant cells; (iii) syncytia; and (iv) coenocytes. Variations in the structure of these cells within each group are also present between some genera depending on the nematode species viz. Meloidogyne or Rotylenchulus. This variability of feeding sites may be related in some way to PPN life style (migratory ectoparasites, sedentary ectoparasites, migratory ecto-endoparasites, migratory endoparasites, or sedentary endoparasites). Apart from their co-evolution with plants, the response of plant cells and roots are closely related to feeding behavior, the anatomy of the nematode (mainly stylet size, which could reach different types of cells in the plant), and the secretory fluids produced in the pharyngeal glands. These secretory fluids are injected through the stylet into perforated cells where they modify plant cytoplasm prior to food removal. Some

  7. Genetic tests of ancient asexuality in Root Knot Nematodes reveal recent hybrid origins

    Directory of Open Access Journals (Sweden)

    Lunt David H

    2008-07-01

    Full Text Available Abstract Background The existence of "ancient asexuals", taxa that have persisted for long periods of evolutionary history without sexual recombination, is both controversial and important for our understanding of the evolution and maintenance of sexual reproduction. A lack of sex has consequences not only for the ecology of the asexual organism but also for its genome. Several genetic signatures are predicted from long-term asexual (apomictic reproduction including (i large "allelic" sequence divergence (ii lack of phylogenetic clustering of "alleles" within morphological species and (iii decay and loss of genes specific to meiosis and sexual reproduction. These genetic signatures can be hard to assess since it is difficult to demonstrate the allelic nature of very divergent sequences, divergence levels may be complicated by processes such as inter-specific hybridization, and genes may have secondary roles unrelated to sexual reproduction. Apomictic species of Meloidogyne root knot nematodes have been suggested previously to be ancient asexuals. Their relatives reproduce by meiotic parthenogenesis or facultative sexuality, which in combination with the abundance of nematode genomic sequence data, makes them a powerful system in which to study the consequences of reproductive mode on genomic divergence. Results Here, sequences from nuclear protein-coding genes are used to demonstrate that the first two predictions of ancient asexuality are found within the apomictic root knot nematodes. Alleles are more divergent in the apomictic taxa than in those species exhibiting recombination and do not group phylogenetically according to recognized species. In contrast some nuclear alleles, and mtDNA, are almost identical across species. Sequencing of Major Sperm Protein, a gamete-specific gene, from both meiotic and ameiotic species reveals no increase in evolutionary rate nor change in substitution pattern in the apomictic taxa, indicating that the locus

  8. Phylogeny of nematodes from birds of prey

    OpenAIRE

    Honisch, Michaela

    2010-01-01

    Birds of prey host a wide variety of endoparasites. The majority of these endoparasites are nematodes. They can be found mainly in the digestive and respiratory system. The current accepted phylogeny of nematodes found in birds of prey is based on morphological traits. In this study molecular data were used to assess phylogenetic relationships in this group of parasitic nematodes. The aim of the study was to evaluate a method for rapid species identification, to construct a phylogeny of paras...

  9. Susceptibilidad de genotipos de Solanum spp. al nematodo causante del nudo radical Meloidogyne spp. (chitwood

    Directory of Open Access Journals (Sweden)

    Gelpud Chaves Cristian

    2011-03-01

    Full Text Available

    El cultivo del lulo (Solanum quitoense L. presenta una disminución en su productividad, debido al ataque de patógenos como el nematodo del nudo radical Meloidogyne  spp., en el Departamento  de Nariño (Colombia, se han reportado incidencias cercanas al 79%, y pérdidas del 50%.   En la presente investigación, se colectaron 45 genotipos de (Solanum quitoense  L. en los Departamentos  de Nariño  y Putumayo  y 4 genotipos  silvestres  (S. mammosum, S. hirtum,       S. marginatum  y S. umbellatum buscando fuentes de resistencia al nematodo. Se inocularon 9 plantas de cada genotipo de dos meses de edad con 10000 huevos de Meloidogyne spp., dejando tres testigos por cada material. Las variables evaluadas fueron: altura de planta, severidad, incidencia, peso fresco (tallo y raíz y especies prevalentes de Meloidogyne spp. Se hizo una clasificación de genotipos mediante escala de resistencia y regresión entre la severidad y las demás variables para establecer el efecto de Meloidogyne spp. sobre los genotipos de planta. Los resultados mostraron 100% de incidencia del nematodo en  todos  los  genotipos,  2.04%  genotipos  resistentes,  34.7%  moderadamente  resistentes, 42.8% moderadamente susceptibles, 18.3% susceptibles, y 2.04% altamente susceptibles. El genotipo SQbr05 resistente, no se vio afectado por la severidad, al contrario SQbc04 genotipo susceptible, mostró reducciones significativas en peso fresco de tallo y raIz, (R2 = 0.71 y 0.98,el genotipo silvestre (S. mammosum es altamente susceptible, Meloidogyne incognita presentó 55.31% de presencia. El genotipo SQbr05 es promisorio para ser evaluado en campo.

  10. Growth and yield of grafted cucumbers in soil infested with root-knot nematodes

    Directory of Open Access Journals (Sweden)

    Smiljana Goreta Ban

    2014-03-01

    Full Text Available The aim of this study was to determine the effect of rootstocks on the growth and yield of cucumber (Cucumis sativus L. plants in soils infested with root-knot nematodes (Meloidogyne spp. Cucumber 'Adrian' was grown with its own roots or was grafted onto three rootstocks of Lagenariasiceraria (Molina Standi. ('Emphasis', 'S-1', and 'Gourd', two interspecific hybrid rootstocks of Cucurbita maxima Duchesne x C. moschata Duchesne ('Strong Tosa' and 'RS 841 Improved' and zucchini Cucurbita pepo L. ('Romanesco Zucchini'. The experiments were conducted in commercial greenhouse, with cucumber grafted onto three rootstocks in the first season and onto six rootstocks in the second spring-summer season. The number of leaves was considerably affected by the rootstock in both seasons, and was the highest for the plants grafted onto interspecific rootstocks (28.0 in the first and 44.9 in the second season. The plants grafted onto 'Strong Tosa' had higher total number of fruits (19.9 and yield (5.38 kg compared to other rootstocks or non-grafted plants in first season, and the same result was found for two interspecific rootstocks in the second season (6.96 kg and more than 28.9 fruits per plant. The total soluble solids, pH and electrical conductivity of the fruit were not affected by rootstock, while titratable acidity changed with the rootstock type. The grafting of cucumber plants onto different rootstocks was confirmed as an acceptable non-chemical method to compete with the limitations of soils infected with root-knot nematodes, but the effect was highly dependent on the choice of the rootstock.

  11. Prunus Rootstock Evaluation to Root-knot and Lesion Nematodes in Spain.

    Science.gov (United States)

    Pinochet, J; Aglès, M; Dalmau, E; Fernández, C; Felipe, A

    1996-12-01

    Two screening and one resistance verification trial involving 20 Prunus rootstocks were conducted under greenhouse conditions against Meloidogyne spp. and Pratylenchus vulnus. Most of the rootstocks were experimental genotypes or new commercial peach and plums of Spanish and French origin. Nearly all are interspecific hybrid rootstocks. In the first trial, the rootstocks Bruce, Cadaman, Mirac, G x N No. 15, Cachirulo x (G x N No. 9), and P. myra x peach were immune or resistant to a mixture of seven isolates of M. incognita. In the second screening trial, the hybrid plum P 2588 was a poor host to a mixture of four isolates of P. vulnus. The remaining seven rootstocks were good hosts to the root-lesion nematode. In the resistance verification trial GF-31, G x N No. 15, Torinel, AD- l 01, Monpol, Nemaguard, and Cadaman maintained a high level of resistance when tested against a mixture of 17 isolates comprising M. incognita, M. javanica, M. arenaria, M. hapla, and M. hispanica. Barrier peach suffered a partial loss of resistance not detected in previous tests.

  12. Identification for the First Time of Cyclo(d-Pro-l-Leu Produced by Bacillus amyloliquefaciens Y1 as a Nematocide for Control of Meloidogyne incognita

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    Qaiser Jamal

    2017-10-01

    Full Text Available The aim of the current study was to describe the role and mechanism of Bacillus amyloliquefaciens Y1 against the root-knot nematode, Meloidogyne incognita, under in vitro and in vivo conditions. Initially, the exposure of the bacterial culture supernatant and crude extract of Y1 to M. incognita significantly inhibited the hatching of eggs and caused the mortality of second-stage juveniles (J2, with these inhibitory effects depending on the length of incubation time and concentration of the treatment. The dipeptide cyclo(d-Pro-l-Leu was identified in B. amyloliquefaciens culture for the first time using chromatographic techniques and nuclear magnetic resonance (NMR 1H, 13C, H-H COSY, HSQC, and HMBC and recognized to have nematocidal activity. Various concentrations of cyclo(d-Pro-l-Leu were investigated for their effect on the hatching of eggs and J2 mortality. Moreover, the in vivo nematocidal activity of the Y1 strain was investigated by conducting pot experiments in which tomato plants were inoculated with M. incognita. Each and every pot was amended 50 mL of fertilizer media (F, or Y1 culture, or nematicide (N (only once, or fertilizer media with N (FN at 1, 2, 3, 4 and 5 weeks after transplantation. The results of the pot experiments demonstrated the antagonistic effect of B. amyloliquefaciens Y1 against M. incognita as it significantly decreases the count of eggs and galls per root of the tomato plant as well as the population of J2 in the soil. Besides, the investigation into the growth parameters, such as the length of shoot, shoot fresh and dry weights of the tomato plants, showed that they were significantly higher in the Y1 strain Y1-treated plants compared to F-, FN- and N-treated plants. Therefore, the biocontrol repertoire of this bacterium opens a new insight into the applications in crop pest control.

  13. Identification for the First Time of Cyclo(d-Pro-l-Leu) Produced by Bacillus amyloliquefaciens Y1 as a Nematocide for Control of Meloidogyne incognita.

    Science.gov (United States)

    Jamal, Qaiser; Cho, Jeong-Yong; Moon, Jae-Hak; Munir, Shahzad; Anees, Muhammad; Kim, Kil Yong

    2017-10-27

    The aim of the current study was to describe the role and mechanism of Bacillus amyloliquefaciens Y1 against the root-knot nematode, Meloidogyne incognita, under in vitro and in vivo conditions. Initially, the exposure of the bacterial culture supernatant and crude extract of Y1 to M. incognita significantly inhibited the hatching of eggs and caused the mortality of second-stage juveniles (J2), with these inhibitory effects depending on the length of incubation time and concentration of the treatment. The dipeptide cyclo(d-Pro-l-Leu) was identified in B. amyloliquefaciens culture for the first time using chromatographic techniques and nuclear magnetic resonance (NMR ¹H, 13 C, H-H COSY, HSQC, and HMBC) and recognized to have nematocidal activity. Various concentrations of cyclo(d-Pro-l-Leu) were investigated for their effect on the hatching of eggs and J2 mortality. Moreover, the in vivo nematocidal activity of the Y1 strain was investigated by conducting pot experiments in which tomato plants were inoculated with M. incognita. Each and every pot was amended 50 mL of fertilizer media (F), or Y1 culture, or nematicide (N) (only once), or fertilizer media with N (FN) at 1, 2, 3, 4 and 5 weeks after transplantation. The results of the pot experiments demonstrated the antagonistic effect of B. amyloliquefaciens Y1 against M. incognita as it significantly decreases the count of eggs and galls per root of the tomato plant as well as the population of J2 in the soil. Besides, the investigation into the growth parameters, such as the length of shoot, shoot fresh and dry weights of the tomato plants, showed that they were significantly higher in the Y1 strain Y1-treated plants compared to F-, FN- and N-treated plants. Therefore, the biocontrol repertoire of this bacterium opens a new insight into the applications in crop pest control.

  14. Tracking movement of Meloidogyne spp and R. reniformis in a plasticulture system

    Science.gov (United States)

    Soil fumigation and in-row treatments of nematicides have been the common protocol for pre-and in-season management of plant parasitic nematodes (PPN’s) in vegetable production. One issue not addressed is the depth at which the highest concentration of nematodes occur. In the United States, applicat...

  15. Condensed tannins act against cattle nematodes

    DEFF Research Database (Denmark)

    Novobilský, Adam; Mueller-Harvey, Irene; Thamsborg, Stig Milan

    2011-01-01

    The use of natural plant anthelmintics was suggested as a possible alternative control of gastrointestinal nematodes (GIN) in ruminants. Direct anthelmintic effects of tannin-containing plants have already been shown in sheep and goat GIN. These anthelmintic properties are mainly associated with ...... extracts. Our results, therefore, indicated that tannin-containing plants could act against cattle nematodes....

  16. Benthic freshwater nematode community dynamics under conditions ...

    African Journals Online (AJOL)

    Studies of the influence of fish aquaculture on benthic freshwater nematode assemblages are scarce, but could provide a way of gauging environmental effects. The abundance and diversity of nematode assemblages in response to Oreochromis niloticus aquaculture were investigated in Kafr El-Sheikh Governorate, Egypt, ...

  17. How do humans affect wildlife nematodes?

    Science.gov (United States)

    Weinstein, Sara B.; Lafferty, Kevin D.

    2015-01-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host–parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

  18. Reação de genótipos de maracujazeiro a Meloidogyne incognita raça 3 e Meloidogyne javanica

    Directory of Open Access Journals (Sweden)

    Leandro Souza Rocha

    2013-12-01

    Full Text Available O objetivo do trabalho foi avaliar a reação de genótipos de maracujazeiro a Meloidogyne spp.. O experimento foi conduzido em casa de vegetação em DBC, com seis repetições, em esquema fatorial 9x2 (Passiflora giberti, P. nitida, P. setacea, P. mucronata, P. cincinnata, P. ligularis, P.alata, híbrido BRS Sol do Cerrado e seleção M19-UFV x Meloidogyne javanica e M. incognita raça 3. Segundo os critérios de Oostenbrink, e Moura e Régis, o BRS Sol do Cerrado, a seleção M-19-UFV e P. alata comportaram-se como imunes a M. incognita. Além destes, P. cincinnata e P. setacea foram imunes a M. javanica. Passiflora cincinnata e P.giberti comportaram-se como resistentes a M. incognita e M. javanica, respectivamente. Segundo Taylor e Sasser, os genótipos classificados como imunes pelos outros critérios foram classificados como resistentes aos nematoides. Todas as variáveis nematológicas avaliadas em P. giberti, P. ligularis, P. mucronata e P. nitida foram superiores em plantas infectadas por M. incognita. Independentemente do nematoide, P. mucronata apresentou maior número de galhas, massas de ovos, ovos, J2 e FR, em relação aos outros genótipos. O peso de matéria fresca de raiz de P. ligularis e P. mucronata foi menor na presença de M. incognita em relação a M. javanica.

  19. Soil properties influencing phytoparasitic nematode population on Chilean vineyards Propiedades del suelo que influyen en la población de nematodos fitoparásitos en viñedos de Chile

    Directory of Open Access Journals (Sweden)

    Mario Fajardo P

    2011-06-01

    Full Text Available Lifecycle of phytoparasitic nematode takes place in the rhizosphere, therefore their breeding, parasitism and mobility dynamics are inevitably influenced by the soil-root interaction, A study was performed to evaluate the influence of Vitis rootstocks to some plant parasitic nematodes under different soil conditions. Nematode populations were assessed in Vitis vinifera L. var ‘Chardonnay’ plants grafted on two rootstocks (K5BB, SO4 and ungrafted ‘Chardonnay’ as a control in three diferent alluvial soils in the central zone of Chile. Soils were two Inceptisols of the Casablanca Valley (Valparaíso Region, the first one without soil structure and with a densification zone in depth (S1 and the second one with sandy textural class (S3. A third soil was a Mollisol (S2 more structured than the others, situated on a locality of Melipilla (Metropolitan Region. The soils were characterized physically and morphologically and nematode genera were identified and counted using a dissecting microscope. ‘Chardonnay’ presented the highest population of Meloidogyne spp. on the three soil conditions but only significant in S2 soil. The population of Xiphinema spp. and Mesocriconema xenoplax were not representative enough to relate them with either soil or the different rootstocks. The amount of Meloidogyne spp. was inversely related with the sand content but positively related with the more structured soil. The stepwise regressions resulted useful when relating nematode populations with multiple soil factors.El ciclo de vida de los nematodos fitoparásitos ocurre en la rizósfera, por lo tanto, sus dinámicas de alimentación, parasitismo y movilidad están inevitablemente influenciadas por la interacción suelo-raíz. Se llevó a cabo un estudio para evaluar la respuesta de diferentes portainjertos de Vitis frente a algunas poblaciones de nematodos fitoparásitos en diferentes tipos de suelos. Se determinaron las poblaciones de nematodos fitopar

  20. Sequence analysis of the D2/D3 region of the large subunit RDNA from different Meloidogyne isolates

    NARCIS (Netherlands)

    Tenente, G.C.M.V.; Ley, de P.; Ley, de I.T.; Karssen, G.; Vanfleteren, J.R.

    2004-01-01

    The phylogenetic relationships of eight Meloidogyne species and twelve isolates from Brazil and other countries were investigated using sequence data of the D2/D3 expansion segments of the large subunit of ribosomal DNA. The phylogenetic procedures used were maximum parsimony, maximum likelihood and

  1. Studies on the interactions of Meloidogyne incognita, Radopholus similis and Fusarium solani on black pepper (Piper nigrum L.)

    NARCIS (Netherlands)

    Mustika, I.

    1990-01-01

    This study on the interactions between various cultivars of the black pepper plant (Piper nigrum L. ) and three of its pathogens, Meloidogyne Incognita (Kofoid & White) , Radopholus similis (Cobb) , Thorne and

  2. Tuber and root resistance of potato genotypes against Meloidogyne chitwoodi in the presence of Avena strigosa, related to tuber quality

    NARCIS (Netherlands)

    Been, Thomas H.; Molendijk, Leendert P.G.; Teklu, Misghina G.; Schomaker, Corrie H.

    2017-01-01

    Relative tuber infestation and quality of two Meloidogyne chitwoodi resistant potato genotypes, AR04-4096 and 2011M1, were compared in glasshouse experiments at initial population density (Pi) = 16 second-stage juveniles (g dry soil)−1 in the presence and absence of the bristle oat, Avena strigosa.

  3. Effects of Anaerobically Digested Slurry on Meloidogyne incognita and Pratylenchus penetrans in Tomato and Radish Production

    International Nuclear Information System (INIS)

    Min, Y.Y; Toyota, K; Sato, E; Takada, A

    2011-01-01

    Since effective disposable way of anaerobically digested biogas slurry is expected, ADS was applied to soil to evaluate its effects on nematode damage. Damage index of tomato by root-knot nematode was significantly (P 4 + -N kg -1 ) than that in those with chemical fertilizer and control (no ADS). ADS was applied into radish cultivated fields infested with the root-lesion nematode: a single (100 kg NH 4 + -N ha -1 ) in 2007 and 2008 and multiple applications (25, 50, 25 kg NH 4 + -N ha -1 soil) in 2009. Damage to radish was 30% and 50% lower in ADS-treated fields than that in the control in 2007 and 2009, respectively, although not in 2008. These results suggest that application of ADS to fields might be feasible for mitigating nematode damage, but the rate and timing should be considered further for the best application way.

  4. Avaliação da resistência de genótipos de quiabeiro à infestação por Meloidogyne incognita raça 2 e M. javanica Resistance of okra genotypes to Meloidogyne incognita race 2 and M. javanica

    Directory of Open Access Journals (Sweden)

    Gilmar Efrem Martinello

    2001-07-01

    Full Text Available Vinte e dois genótipos de quiabeiro (Abelmoschus spp. foram avaliados para resistência à Meloidogyne incognita raça 2 e M. javanica. Estes materiais, mantidos no Banco de Germoplasma da Universidade Estadual do Norte Fluminense, constam de quatro espécies selvagens Abelmoschus manihot (CGO 8655, A. caillei (CGO 8656, A. tetraphyllus (CGO 8657 e A. ficulneus (CGO 8658; 16 linhas de A. esculentus na sétima geração de autofecundação, resultantes de inter-cruzamentos do genótipo PI-357991 (supostamente resistentes a nematóides com as cultivares Piranema e Santa Cruz 47. Essas cultivares serviram como padrão de suscetibilidade. As plantas foram inoculadas separadamente com 5.000 ovos/segundo estádio juvenil (J2 de M. incognita raça 2 e M. javanica. Não houve diferença significativa com relação à resistência dos materiais a M. javanica. Os genótipos descendentes de 'PI-357991' mostraram-se segregantes para a reação de resistência, sendo que entre estes 'CGO 8180A7' apresentou o maior nível de tolerância à raça 2 de M. incognita. As espécies silvestres também não mostraram alguma fonte de resistência. As altas temperaturas ocorridas no período do experimento, podem ter aumentado a suscetibilidade dos genótipos aos dois patógenos.Twenty two okra genotypes were evaluated for resistance to M. incognita race 2 and M. javanica. The Universidade Estadual do Norte Fluminense (Brazil maintains okra genotypes in the germplasm collection, consisting of four wild Abelmoschus species and 16 F7 lines obtained from crosses between PI-357991 (considered resistant to root-knot nematodes and the local cvs, Piranema and Santa Cruz 47 (both susceptible to nematodes. No resistance was observed among okra genotypes to infection by M. javanica. The 16 F7 lines segregated for pathogenic reaction, and the CGO 8180A7 presented the highest resistance level to M. incognita race 2. The wild species did not show genetic resistance to both

  5. Parasitic Nematode Interactions with Mammals and Plants

    NARCIS (Netherlands)

    Jasmer, D.P.; Goverse, A.; Smant, G.

    2003-01-01

    Parasitic nematodes that infect humans, animals, and plants cause serious diseases that are deleterious to human health and agricultural productivity. Chemical and biological control methods have reduced the impact of these parasites. However, surviving environmental stages lead to persistent

  6. WormBase: Annotating many nematode genomes.

    Science.gov (United States)

    Howe, Kevin; Davis, Paul; Paulini, Michael; Tuli, Mary Ann; Williams, Gary; Yook, Karen; Durbin, Richard; Kersey, Paul; Sternberg, Paul W

    2012-01-01

    WormBase (www.wormbase.org) has been serving the scientific community for over 11 years as the central repository for genomic and genetic information for the soil nematode Caenorhabditis elegans. The resource has evolved from its beginnings as a database housing the genomic sequence and genetic and physical maps of a single species, and now represents the breadth and diversity of nematode research, currently serving genome sequence and annotation for around 20 nematodes. In this article, we focus on WormBase's role of genome sequence annotation, describing how we annotate and integrate data from a growing collection of nematode species and strains. We also review our approaches to sequence curation, and discuss the impact on annotation quality of large functional genomics projects such as modENCODE.

  7. Genome Evolution of Plant-Parasitic Nematodes.

    Science.gov (United States)

    Kikuchi, Taisei; Eves-van den Akker, Sebastian; Jones, John T

    2017-08-04

    Plant parasitism has evolved independently on at least four separate occasions in the phylum Nematoda. The application of next-generation sequencing (NGS) to plant-parasitic nematodes has allowed a wide range of genome- or transcriptome-level comparisons, and these have identified genome adaptations that enable parasitism of plants. Current genome data suggest that horizontal gene transfer, gene family expansions, evolution of new genes that mediate interactions with the host, and parasitism-specific gene regulation are important adaptations that allow nematodes to parasitize plants. Sequencing of a larger number of nematode genomes, including plant parasites that show different modes of parasitism or that have evolved in currently unsampled clades, and using free-living taxa as comparators would allow more detailed analysis and a better understanding of the organization of key genes within the genomes. This would facilitate a more complete understanding of the way in which parasitism has shaped the genomes of plant-parasitic nematodes.

  8. Root morphology of several potato varieties - infected Meloidogyne spp. and addition of organic matters

    Science.gov (United States)

    Lubis, K.; Lubis, A. M.; Siregar, L. A. M.; Lisnawita; Safni, I.; Tantawi, A. R.

    2018-02-01

    This research was aimed to determine root morphology of several potato varieties which were applied by organic materials into the planting medium inoculated nematodes. The research was conducted at Research Station of Horticulture in Berastagi, Sumatera Utara on May to November 2016. The randomized block design was used with two factors; the first factor was K1 = Positive control (no use compost / inoculation of nematodes) K2 = Negative control (no use compost / no inoculation of nematodes) K3 = Using compost mucuna and inoculation of nematode, K4 = Using compost peanuts and inoculation of nematodes and the second factor was potato varieties (Tenggo, Maglia, and Margahayu). The results showed that organic matters increased the shoot fresh weight, the root fresh weight, the tubers weight and the number of tubers, root diameter, root lenght. However, organic matters also increased the number of nematodes. Varieties of Tenggo and Maglia showed significant affect to all observed characters. The interaction of the two treatments had significant affect to the shoot fresh weight, the number of root-knot, and the number of tubers, root lenght. However, no significant affect was observed in root wet weight, and tuber weight.

  9. Growing Tomato ( Lycopersicon esculentum L.) in Nematode ...

    African Journals Online (AJOL)

    Parasitic root-knot nematodes are a threat to tomato production. In this study, the effect of Procarvian carpensis manure at a rate of 5tons/ha and the balanced NPK inorganic fertilizer at a rate of 100kg/ha on the growth performance of the tomato genotype “Duluti” on a highly root-knot nematode soil was evaluated. The field ...

  10. Tropical nematode diversity: vertical stratification of nematode communities in a Costa Rican humid lowland rainforest.

    Science.gov (United States)

    Powers, T O; Neher, D A; Mullin, P; Esquivel, A; Giblin-Davis, R M; Kanzaki, N; Stock, S P; Mora, M M; Uribe-Lorio, L

    2009-03-01

    Comparisons of nematode communities among ecosystems have indicated that, unlike many organisms, nematode communities have less diversity in the tropics than in temperate ecosystems. There are, however, few studies of tropical nematode diversity on which to base conclusions of global patterns of diversity. This study reports an attempt to estimate nematode diversity in the lowland tropical rainforest of La Selva Biological Research Station in Costa Rica. We suggest one reason that previous estimates of tropical nematode diversity were low is because habitats above the mineral soil are seldom sampled. As much as 62% of the overall genetic diversity, measured by an 18S ribosomal barcode, existed in litter and understorey habitats and not in soil. A maximum-likelihood tree of barcodes from 360 individual nematodes indicated most major terrestrial nematode lineages were represented in the samples. Estimated 'species' richness ranged from 464 to 502 within the four 40 x 40 m plots. Directed sampling of insects and their associated nematodes produced a second set of barcodes that were not recovered by habitat sampling, yet may constitute a major class of tropical nematode diversity. While the generation of novel nematode barcodes proved relatively easy, their identity remains obscure due to deficiencies in existing taxonomic databases. Specimens of Criconematina, a monophyletic group of soil-dwelling plant-parasitic nematodes were examined in detail to assess the steps necessary for associating barcodes with nominal species. Our results highlight the difficulties associated with studying poorly understood organisms in an understudied ecosystem using a destructive (i.e. barcode) sampling method.

  11. Fungi associated with free-living soil nematodes in Turkey

    Directory of Open Access Journals (Sweden)

    Karabörklü Salih

    2015-01-01

    Full Text Available Free-living soil nematodes have successfully adapted world-wide to nearly all soil types from the highest to the lowest of elevations. In the current study, nematodes were isolated from soil samples and fungi associated with these free-living soil nematodes were determined. Large subunit (LSU rDNAs of nematode-associated fungi were amplified and sequenced to construct phylogenetic trees. Nematode-associated fungi were observed in six nematode strains belonging to Acrobeloides, Steinernema and Cephalobus genera in different habitats. Malassezia and Cladosporium fungal strains indicated an association with Acrobeloides and Cephalobus nematodes, while Alternaria strains demonstrated an association with the Steinernema strain. Interactions between fungi and free-living nematodes in soil are discussed. We suggest that nematodes act as vectors for fungi.

  12. Nematode Interactions in Nature: Models for Sustainable Control of Nematode Pests of Crop Plants?

    NARCIS (Netherlands)

    Putten, van der W.H.; Cook, R.; Costa, S.; Davies, K.G.; Fargette, M.; Freitas, H.; Hol, W.H.G.; Kerry, B.R.; Maher, N.; Mateille, T.; Moens, M.; Peña, de la E.; Piskiewicz, A.M.; Raeymaekers, A.D.W.; Rodriquez-Echeverria, S.; Wurff, van der A.W.G.

    2006-01-01

    Plant-parasitic nematodes are major crop pests in agro-ecosystems while in nature their impact may range from substantial to no significant growth reduction. The aim of this review is to determine if nematode population control in natural ecosystems may provide us with a model for enhancing

  13. Nematode interactions in nature: models for sustainable control of nematode pests of crop plants?

    NARCIS (Netherlands)

    Van der Putten, W.H.; Cook, R.; Costa, S.R.; Davies, K.G.; Fargette, M.; Freitas, H.; Hol, W.H.G.; Kerry, B.R.; Maher, N.; Mateille, T.; Moens, M.; De la Peña, E.; Piskiewicz, A.; Raeymaekers, A.; Rodríguez-Echeverría, S.; Van der Wurff, A.W.G.

    2006-01-01

    Plant-parasitic nematodes are major crop pests in agro-ecosystems while in nature their impact may range from substantial to no significant growth reduction. The aim of this review is to determine if nematode population control in natural ecosystems may provide us with a model for enhancing

  14. Eksplorasi Bakteri yang Berpotensi Sebagai Agens Pengendali Hayati Fusarium solani dan Meloidogyne incognita pada Lada

    Directory of Open Access Journals (Sweden)

    Citra Mayang Wardhika

    2014-12-01

    Full Text Available Indonesia is major producer of black pepper (Piper nigrum L., however the pepper production has been decreasing in the last decades. Black pepper yellowings caused by Fusarium solani and Meloidogyne incognita is one of the most important disease on pepper causing the decrease of pepper production. This research was aimed at the selection of potential bacteria as a biological control agents of F. solani and M. incognita on black pepper. The bacteria were isolated from rhizospheric soil of healthy plant. To determine the ability of biological agents, they were tested against F. solani and M. incognita. Seven isolates fluorescent pseudomonads, 19 isolates of Bacillus spp. and 21 bacterial isolates which were yet to be identified were isolated from soil rhizosphere. The results show that there are 5 antagonist bacterial isolates which were able to inhibit the growth of F. solani but so far no bacteria that caused cell lysis to M. incognita larvae was found.     Indonesia merupakan negara produsen lada yang pada beberapa waktu terakhir ini telah mengalami penurunan produksi. Penyakit kuning yang disebabkan oleh Fusarium solani dan Meloidogyne incognita merupakan salah satu penyebab terjadinya penurunan tersebut. Penelitian bertujuan untuk menyeleksi bakteri yang berpotensi sebagai pengendali hayati Fusarium solani dan Meloidogyne incognita pada lada. Isolasi bakteri dilakukan dari tanah rizosfer pertanaman lada sehat dan selanjutnya untuk mengetahui kemampuan agens hayati dilakukan uji antagonis terhadap F. solani dan M. incognita. Hasil isolasi dari rizosfer pertanaman didapatkan 7 isolat bakteri kelompok Pseudomonad fluoresen, 19 isolat bakteri Bacillus spp. dan 21 isolat bakteri yang belum diidentifikasi lebih lanjut. Hasil uji antagonis menunjukkan bahwa ada 5 isolat bakteri yang mampu menghambat pertumbuhan F. solani namun belum ditemukan adanya bakteri yang mampu menghambat pertumbuhan M. incognita.

  15. Establishment of Orchards with Black Polyethylene Film Mulching: Effect on Nematode and Fungal Pathogens, Water Conservation, and Tree Growth

    Science.gov (United States)

    Duncan, R. A.; Stapleton, J. J.; McKenry, M. V.

    1992-01-01

    Placement of a 3-m-wide, black, polyethylene film mulch down rows of peach (Prunus persica 'Red Haven' on 'Lovell' rootstock) and almond (Prunus dulcis 'Nonpareil' on 'Lovell') trees in the San Joaquin Valley of California resulted in irrigation water conservation of 75%, higher soil temperature in the surface 30 cm, a tendency toward greater root mass, elimination of weeds, and a greater abundance of Meloidogyne incognita second-stage juveniles in soil but reduced root galling when compared to the nonmulched control. Population levels of Pratylenchus hexincisus, a nematode found within tree roots, were reduced by mulching, as were those of Tylenchulus semipenetrans, which survived on old grape roots remaining from a previously planted vineyard, and Paratrichodorus minor, which probably fed on roots of various weed species growing in the nonmulched soil. Populations of Pythium ultimum were not significantly changed, probably also due to the biological refuge of the old grape roots and moderate soil heating level. Trunk diameters of peach trees were increased by mulching, but those of almond trees were reduced by the treatment. Leaf petiole analysis indicated that concentrations of mineral nutrients were inconsistent, except for a significant increase in Ca in both tree species. PMID:19283045

  16. Resistance of Newly Introduced Vegetables to Meloidogyne arenaria and M. incognita in Korea

    Directory of Open Access Journals (Sweden)

    Donggeun Kim

    2013-12-01

    Full Text Available To select resistant vegetables against two species of root-knot nematodes, M. incognita and M. arenaria, 39 vegetables belongs to 7 families, 13 genera, 25 species were screened in greenhouse pot test. Susceptible vegetables to both nematodes were amarath and leaf beet in Amaranthaceae, Malabar spinach in Basellaceae, Moroheiya in Tiliaceae, and Water-convolvulus in Convolvulaceae, Pak-choi in Brassica campestris var. chinensis, Tah tasai in B. campestris var. narinosa, B. campestris var. chinensis x narinosa, Leaf mustard, Mustard green in B. juncea, Kyona in B. juncea var. laciniate, Choy sum in B. rapa subsp. arachinenesis, Kairan in B. oleracea var. alboglabra, Arugula in Eruca sativa, Garland chrysanthemum in Chrysanthemum coronarium, Endive in Cichorium endivia, Artichoke in Cynara cardunculus var. scolymus, Lettuce in Lactuca sativa. Resistant to M. arenaria but susceptible to M. incognita were B. oleracea cv. Matjjang kale, B. oleracea var. gongyloides cv. Jeok kohlrabi, and C. intybus cv. Radicchio. Resistant vegetables to both nematodes were C. intybus cv. Sugar loaf, Grumoro, Radichio treviso, B. oleracea cv. Manchu collard, Super matjjang, B. oleracea italica, B. oleracea var. botrytis italiana, and Perilla in Lamiaceae. Vegetables resistant to both species of root-knot nematodes could be used as high-valued rotation crops in greenhouses where root-knot nematodes are problem.

  17. Differential response to root-knot nematodes in prunus species and correlative genetic implications.

    Science.gov (United States)

    Esmenjaud, D; Minot, J C; Voisin, R; Pinochet, J; Simard, M H; Salesses, G

    1997-09-01

    Responses of 17 Prunus rootstocks or accessions (11 from the subgenus Amygdalus and 6 from the subgenus Prunophora) were evaluated against 11 isolates of Meloidogyne spp. including one M. arenaria, four M. incognita, four M. javanica, one M. hispanica, and an unclassified population from Florida. Characterization of plant response to root-knot nematodes was based on a gall index rating. Numbers of females and juveniles plus eggs in the roots were determined for 10 of the rootstocks evaluated against one M. arenaria, one M. incognita, one M. javanica, and the Florida isolate. These 10 rootstocks plus Nemaguard and Nemared were retested by growing three different rootstock genotypes together in containers of soil infested individually with each of the above four isolates. Garfi and Garrigues almonds, GF.305 and Rutgers Red Leaf peaches, and the peach-almond GF.677 were susceptible to all isolates. Differences in resistance were detected among the other rootstocks of the subgenus Amygdalus. The peach-almond GF.557 and Summergrand peach were resistant to M. arenaria and M. incognita but susceptible to M. javanica and the Florida isolate. Nemaguard, Nemared, and its two hybrids G x N no. 15 and G x N no. 22 were resistant to all but the Florida isolate. In the subgenus Prunophora, Myrobalan plums P.1079, P.2175, P.2980, and P.2984; Marianna plum 29C; and P. insititia plum AD.101 were resistant to all isolates. Thus, two different genetic systems of RKN resistance were found in the subgenus Amygdalus: one system acting against M. arenaria and M. incognita, and another system also acting against M. javanica. Prunophora rootstocks bear a complete genetic system for resistance also acting against the Florida isolate. The hypotheses on the relationships between these systems and the corresponding putative genes of resistance are presented.

  18. Pathogenicity of four species of meloidogyne on three varieties of olive trees.

    Science.gov (United States)

    Lamberti, F; Baines, R C

    1969-04-01

    'Ascolano' and 'Sevillano' olive trees, Olea europaea L., were highly susceptible to Meloidogyne javanica (Trueb) Chitwood, and growth of their tops was decreased greatly in tests in a glasshouse. Roots of 'Manzanillo' olive trees were galled moderately by M. javanica, and their tops weighed 6% less than those of noninoculated trees. 'Manzanillo' olive is considered highly tolerant to M. javanica. 'Ascolano' and 'Manzanillo' olive trees were highly susceptible to M. incognita (Kofoid &White) Chitwood. Their roots were galled moderately to severely, and growth of their tops were decreased between 13% and 44%. 'Ascolano' and 'Manzanillo' olive trees were considered to be highly resistant to M. arenaria (Neal) Chitwood and M. hapla Chitwood since no galls or mature females were found on their roots three and one-half months after inoculation.

  19. Subproduto da indústria vinícola no controle de Meloidogyne javanica

    OpenAIRE

    Reiner, Driéli Aparecida

    2015-01-01

    Os objetivos deste estudo foram avaliar a eficiência da atividade nematicida de diferentes concentrações do extrato aquoso do subproduto da indústria vinícola sobre a eclosão e a mortalidade de juvenis de segundo estádio (J2) de Meloidogyne javanica e o efeito da incorporação ao solo desse subproduto sobre a eclosão e a viabilidade de J2 do nematoide; identificar, por meio da análise de cromatografia líquida de alta eficiência, a composição fitoquímica do extrato aquoso do subproduto da indús...

  20. Survey and effects of plant parasitic root nematodes of cashew ...

    African Journals Online (AJOL)

    . Five thousand, one hundred and twenty cashew trees were sampled and nematodes in their rhizospheres extracted by modified Cobb's decanting and sieving technique. Pure cultures of the nematodes were further inoculated on 30 days old ...

  1. Different responses of soybean cyst nematode resistance between ...

    Indian Academy of Sciences (India)

    YONGCHUN LI

    parasitic nematode that feeds on the roots of soybean and most economically ... sified pest problems (Skorupska et al. 1994). Soybean cyst nematode .... Genomic DNA extraction and pooling for bulk segregant analysis. Genomic DNA was isolated ...

  2. Nematode-plant interactions in grasslands under restoration management

    NARCIS (Netherlands)

    Verschoor, B.C.

    2001-01-01

    Keywords : competition, fertilisation, food quality, grassland, herbivory, nitrogen, nutrients, plant-feeding nematodes, productivity, restoration management, succession, synergism, vegetation

    Plant-feeding nematodes may have a considerable

  3. How anthropogenic changes may affect soil-borne parasite diversity? Plant-parasitic nematode communities associated with olive trees in Morocco as a case study.

    Science.gov (United States)

    Ali, Nadine; Tavoillot, Johannes; Besnard, Guillaume; Khadari, Bouchaib; Dmowska, Ewa; Winiszewska, Grażyna; Fossati-Gaschignard, Odile; Ater, Mohammed; Aït Hamza, Mohamed; El Mousadik, Abdelhamid; El Oualkadi, Aïcha; Moukhli, Abdelmajid; Essalouh, Laila; El Bakkali, Ahmed; Chapuis, Elodie; Mateille, Thierry

    2017-02-06

    Plant-parasitic nematodes (PPN) are major crop pests. On olive (Olea europaea), they significantly contribute to economic losses in the top-ten olive producing countries in the world especially in nurseries and under cropping intensification. The diversity and the structure of PPN communities respond to environmental and anthropogenic forces. The olive tree is a good host plant model to understand the impact of such forces on PPN diversity since it grows according to different modalities (wild, feral and cultivated olives). A wide soil survey was conducted in several olive-growing regions in Morocco. The taxonomical and the functional diversity as well as the structures of PPN communities were described and then compared between non-cultivated (wild and feral forms) and cultivated (traditional and high-density olive cultivation) olives. A high diversity of PPN with the detection of 117 species and 47 genera was revealed. Some taxa were recorded for the first time on olive trees worldwide and new species were also identified. Anthropogenic factors (wild vs cultivated conditions) strongly impacted the PPN diversity and the functional composition of communities because the species richness, the local diversity and the evenness of communities significantly decreased and the abundance of nematodes significantly increased in high-density conditions. Furthermore, these conditions exhibited many more obligate and colonizer PPN and less persister PPN compared to non-cultivated conditions. Taxonomical structures of communities were also impacted: genera such as Xiphinema spp. and Heterodera spp. were dominant in wild olive, whereas harmful taxa such as Meloidogyne spp. were especially enhanced in high-density orchards. Olive anthropogenic practices reduce the PPN diversity in communities and lead to changes of the community structures with the development of some damaging nematodes. The study underlined the PPN diversity as a relevant indicator to assess community

  4. Extended phenotype: nematodes turn ants into bird-dispersed fruits

    DEFF Research Database (Denmark)

    Hughes, D P; Kronauer, D J C; Boomsma, J J

    2008-01-01

    A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs.......A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs....

  5. Microbial ecology and nematode control in natural ecosystems

    NARCIS (Netherlands)

    Costa, S.R.; Van der Putten, W.H.; Kerry, B.R.

    2011-01-01

    Plant-parasitic nematodes have traditionally been studied in agricultural systems, where they can be pests of importance on a wide range of crops. Nevertheless, nematode ecology in natural ecosystems is receiving increasing interest because of the role of nematodes in soil food webs, nutrient

  6. Selectable genetic markers for nematode transgenesis.

    Science.gov (United States)

    Giordano-Santini, Rosina; Dupuy, Denis

    2011-06-01

    The nematode Caenorhabditis elegans has been used to study genetics and development since the mid-1970s. Over the years, the arsenal of techniques employed in this field has grown steadily in parallel with the number of researchers using this model. Since the introduction of C. elegans transgenesis, nearly 20 years ago, this system has been extensively used in areas such as rescue experiments, gene expression studies, and protein localization. The completion of the C. elegans genome sequence paved the way for genome-wide studies requiring higher throughput and improved scalability than provided by traditional genetic markers. The development of antibiotic selection systems for nematode transgenesis addresses these requirements and opens the possibility to apply transgenesis to investigate biological functions in other nematode species for which no genetic markers had been developed to date.

  7. Remote Sensing of Parasitic Nematodes in Plants

    Science.gov (United States)

    Lawrence, Gary W.; King, Roger; Kelley, Amber T.; Vickery, John

    2007-01-01

    A method and apparatus for remote sensing of parasitic nematodes in plants, now undergoing development, is based on measurement of visible and infrared spectral reflectances of fields where the plants are growing. Initial development efforts have been concentrated on detecting reniform nematodes (Rotylenchulus reniformis) in cotton plants, because of the economic importance of cotton crops. The apparatus includes a hand-held spectroradiometer. The readings taken by the radiometer are processed to extract spectral reflectances at sixteen wavelengths between 451 and 949 nm that, taken together, have been found to be indicative of the presence of Rotylenchulus reniformis. The intensities of the spectral reflectances are used to estimate the population density of the nematodes in an area from which readings were taken.

  8. Meloidogyne javanica Chorismate Mutase Transcript Expression Profile Using Real-Time Quantitative RT-PCR

    OpenAIRE

    Painter, Janet E.; Lambert, Kris N.

    2003-01-01

    A developmental expression profile of the Meloidodgyne javanica esophageal gland gene chorismate mutase-1 (Mj-cm-1) could suggest when in the lifecycle of the nematode the Mj-cm-1 product is functional. This study used real-time quantitative RT-PCR to examine the variation in Mj-cm-1 transcript levels over six timepoints in the nematode lifecycle: egg, infective second-stage juveniles (Inf-J2), 2-day post-inoculation (pi), 7-day pi, 14-day pi, and adult. The Mj-cm-1 mRNA levels peaked at 2-da...

  9. Evaluation of plant aqueous extracts, added into the soil, on Meloidogyne javanica (Treub, 1885 Chitwood, 1949 / Avaliação de extratos aquosos de várias espécies vegetais, aplicados ao solo, sobre Meloidogyne javanica (Treub, 1885 Chitwood, 1949

    Directory of Open Access Journals (Sweden)

    Leandro Grassi de Freitas

    2009-10-01

    Full Text Available The use of plant extracts with nematicidal properties to control plant nematodes can be a useful alternative to small farmers, regarding its low cost and non-toxic effects. The effect of the addition into the soil of aqueous extracts of 20 plant species on Meloidogyne javanica in plants of tomato was studied at greenhouse conditions. These were divided into two groups and evaluated in two separate experiments.The soil in the 2.0 L pots was infested with 5,000 eggs and, in the same day, it was applied 20 mL of aqueous extracts of the 20 plant species (Chrysanthemum parthenium, Arctium lappa, Cymbopogon citratus, Bacharis trimera, Equisetum sp., Melia azedarach, Mentha sp., Ricinus communis, Ocimum basilicum, Momordica charantia, Ruta graveolens, Coleus barbatus, Symphitum officinalis, Polygonum acre, Canavalia ensiformis, Foeniculum vulgare, Petiveria alliacea, Ageratum conyzoides, Mucuna pruriens and Azadirachta indica. Distilled water was used as control. Sixty days later, were evaluated for plant height, the fresh weight of shoot and root and the numbers of galls and eggs per root system. The extracts of Mentha sp., Arctium lappa and Ricinus communis reduced the number of galls of M. javanica in 75.6%; 65.7% and 54.4%; and the number of eggs in 81.7%, 75.9% and 56.6%, respectively.O uso de extratos vegetais com propriedades nematicidas no controle de fitonematóides representa mais uma alternativa para os pequenos produtores, com valor prático e econômico, e sem riscos de contaminação do ambiente. A adição ao solo dos extratos aquosos de 20 espécies de plantas foi avaliada sobre a população de Meloidogyne javanica em plantas de tomateiro, em casa de vegetação. Estas foram divididas em dois grupos e avaliadas em dois experimentos separados. No mesmo dia em que se infestou o solo com 5.000 ovos do nematóide, adicionou-se 20 mL dos extratos aquosos obtidos de folhas de artemísia (Chrysanthemum parthenium, bardana (Arctium lappa

  10. Effects of Anaerobically Digested Slurry on Meloidogyne incognita and Pratylenchus penetrans in Tomato and Radish Production

    Directory of Open Access Journals (Sweden)

    Yu Yu Min

    2011-01-01

    Full Text Available Since effective disposable way of anaerobically digested biogas slurry is expected, ADS was applied to soil to evaluate its effects on nematode damage. Damage index of tomato by root-knot nematode was significantly (<.05 lower and the growth better in pots applied with ADS (100 and 200 mg NH+4-N kg−1 than that in those with chemical fertilizer and control (no ADS. ADS was applied into radish cultivated fields infested with the root-lesion nematode: a single (100 kg NH+4-N ha−1 in 2007 and 2008 and multiple applications (25, 50, 25 kg NH+4-N ha−1 soil in 2009. Damage to radish was 30% and 50% lower in ADS-treated fields than that in the control in 2007 and 2009, respectively, although not in 2008. These results suggest that application of ADS to fields might be feasible for mitigating nematode damage, but the rate and timing should be considered further for the best application way.

  11. Suppression of Meloidogyne incognita by extracts and powdered fruits of Gleditsia sinensis (Chinese honeylocust)

    Science.gov (United States)

    Although the Chinese honeylocust (Gleditsia sinensis) is receiving extensive pharmacological investigation because of its use in traditional Chinese medicine, little work has been undertaken to investigate use of G. sinensis products as soil amendments or as sources of nematode-antagonistic phytoche...

  12. The Elusive Search for Reniform Nematode Resistance in Cotton.

    Science.gov (United States)

    Khanal, Churamani; McGawley, Edward C; Overstreet, Charles; Stetina, Salliana R

    2018-02-05

    The reniform nematode (Rotylenchulus reniformis Linford and Oliveira) has emerged as the most important plant-parasitic nematode of cotton in the United States cotton belt. Success in the development of reniform nematode-resistant upland cotton cultivars (Gossypium hirsutum L.) has not been realized despite over three decades of breeding efforts. Research approaches ranging from conventional breeding to triple species hybrids to marker-assisted selection have been employed to introgress reniform nematode resistance from other species of cotton into upland cultivars. Reniform nematode-resistant breeding lines derived from G. longicalyx were developed in 2007. However, these breeding lines displayed stunting symptoms and a hypersensitive response to reniform nematode infection. Subsequent breeding efforts focused on G. barbadense, G. aridum, G. armoreanum, and other species that have a high level of resistance to reniform nematode. Marker-assisted selection has greatly improved screening of reniform nematode-resistant lines. The use of advanced molecular techniques such as CRISPER-Cas9 systems and alternative ways such as delivery of suitable "cry" proteins and specific double-stranded RNA to nematodes will assist in developing resistant cultivars of cotton. In spite of the efforts of cotton breeders and nematologists, successes are limited only to the development of reniform nematode-resistant breeding lines. In this article, we provide an overview of the approaches employed to develop reniform nematode-resistant upland cotton cultivars in the past, progress to date, major obstacles, and some promising future research activity.

  13. Identification of MicroRNAs in Meloidogyne incognita Using Deep Sequencing.

    Directory of Open Access Journals (Sweden)

    Yunsheng Wang

    Full Text Available MicroRNAs play important regulatory roles in eukaryotic lineages. In this paper, we employed deep sequencing technology to sequence and identify microRNAs in M. incognita genome, which is one of the important plant parasitic nematodes. We identified 102 M. incognita microRNA genes, which can be grouped into 71 nonredundant miRNAs based on mature sequences. Among the 71 miRANs, 27 are known miRNAs and 44 are novel miRNAs. We identified seven miRNA clusters in M. incognita genome. Four of the seven clusters, miR-100/let-7, miR-71-1/miR-2a-1, miR-71-2/miR-2a-2 and miR-279/miR-2b are conserved in other species. We validated the expressions of 5 M. incognita microRNAs, including 3 known microRNAs (miR-71, miR-100b and let-7 and 2 novel microRNAs (NOVEL-1 and NOVEL-2, using RT-PCR. We can detect all 5 microRNAs. The expression levels of four microRNAs obtained using RT-PCR were consistent with those obtained by high-throughput sequencing except for those of let-7. We also examined how M. incognita miRNAs are conserved in four other nematodes species: C. elegans, A. suum, B. malayi and P. pacificus. We found that four microRNAs, miR-100, miR-92, miR-279 and miR-137, exist only in genomes of parasitic nematodes, but do not exist in the genomes of the free living nematode C. elegans. Our research created a unique resource for the research of plant parasitic nematodes. The candidate microRNAs could help elucidate the genomic structure, gene regulation, evolutionary processes, and developmental features of plant parasitic nematodes and nematode-plant interaction.

  14. Evaluation of Verticilum Chlamydosporium and Arrthrobotrys for Biological Control of Meloidogyne Incognita in Celery and Tomato

    International Nuclear Information System (INIS)

    Nyongesa, W.M.

    2002-01-01

    The ability of nematode trapping fungi and egg-parasitic fungi to colonize and persist in the rhizosphere of crop plants is thought to be an important factor influencing the success of bi logical control of root infecting nematodes. In this study, two strains of an egg parasite fungus Verticillium chlamydosporium (Vc-10 and Vc-2M) and an isolate of the nematode-trapping fungus Arthrobotrys oligospora and persistence in the rhizosphere and tomato plants in a green house pot experiment. The isolates tested differed in their pathogenicity to M. incognita and survival in the rhizosphere. An isolate of Verticillum chlamydosporium (Vc-10) was the most virulent pathogen of the nematode. Root galling was slowest in tomato plants treated with V-10 (2.2); pots treated with this isolate had the lowest final soil population of infective juveniles; there was a 62.2% and 98.5% infections of eggs and egg masses respectively by Vc-10 on tomato plants. The two isolates of Verticillium chlamydosporium (Vc-10 and Vc2M) persisted in the soil and could be re-isolated from the rhizosphere and roots of tomato plants at least 16 weeks after soil application. The final inoculum density was, however higher for Vc-10 (1.35x10 5 cfu/g soil) than Vc-2M (9.25x10 4 cfu/g soil). Arthrobotrys oligospora on the other hand did not give any significant control of the nematode on both crops, there was severe galling on the roots of plants treated with this agent. It could not be re-isolated from the plant rhizosphere sixteen weeks after soil infestation. Lack of nematode control on both crops by A.oligo spora was attributed to it's poor on establishment in the plant rhizosphere; low density and roots penetration by infective juveniles before they were ensnared in the trapping devices of this fungal biocontrol agent. The fact that it could not be re-isolated from the rhizosphere may imply that the fungus did not survive in the rhizosphere in quantities enough to enhance nematode control

  15. Nematode populations as influenced by Leucaena leucocephala ...

    African Journals Online (AJOL)

    study to determine the effect of Flemingia congesta and Leucaena leucocephala hedgerows, as sources of mulch, on the population of nematode species in an alley cropping system was conducted at the Crops Research Institute, Kumasi, Ghana from May 1991 to February 1994. Treatments comprised Leucaena ...

  16. Evaluation of nematode suppression and yield improvement ...

    African Journals Online (AJOL)

    SARAH

    2017-11-30

    Nov 30, 2017 ... Objective: To investigate nematode suppression and yield improvement potential of two organic materials; poultry manure ... region of Ghana. The organic materials were applied on two sweet potato varieties; Apomuden and Santom ..... but a trend similar to what happened in 2014 occurred at. Atebubu.

  17. Cell cycle activation by plant parasitic nematodes

    NARCIS (Netherlands)

    Goverse, A.; Almeida Engler, de J.; Verhees, J.; Krol, van der S.; Helder, J.; Gheysen, G.

    2000-01-01

    Sedentary nematodes are important pests of crop plants. They are biotrophic parasites that can induce the (re)differentiation of either differentiated or undifferentiated plant cells into specialized feeding cells. This (re)differentiation includes the reactivation of the cell cycle in specific

  18. TABLE PREVALENCE OF GIT NEMATODES IN CATTLE

    African Journals Online (AJOL)

    User

    A study was carried out on the prevalence of gastrointestinal (GI) nematodes infection in naturally infected cattle in Ogbomoso area of Oyo State using standard parasitological techniques. The results indicated that out of the 1000 cattle examined, 30(3%) were infected and parasites identified were Haemonchus contortus.

  19. Prevalence of parasitic gastrointestinal nematodes of small ...

    African Journals Online (AJOL)

    A cross-sectional study was conducted from December, 2014 to May, 2015 on 914 animals (345 sheep and 569 goats) at Jalingo abattoir, Taraba State, Nigeria based on faecal examination. The objective of the study was to determine the prevalence rate of parasitic gastrointestinal nematodes in slaughtered small ...

  20. Nematode survival in relation to soil moisture

    NARCIS (Netherlands)

    Simons, W.R.

    1973-01-01

    Established nematode populations are very persistent in the soil. It is known that they need sufficient soil moisture for movement, feeding and reproduction (fig. 5), and that there are adverse soil moisture conditions which they cannot survive. The influence of soil moisture on survival

  1. Epidemiology and Control of Gastrointestinal Nematodes Infections ...

    African Journals Online (AJOL)

    A study on the epidemiology and control of gastrointestinal nematode infections in lambs in a semi-arid area of Kajiado District of Kenya was carried out between January 2001 and December 2001. Forty Dorper lambs were randomly recruited at the age of 6 weeks and their faecal samples examined for strongyle-type ...

  2. Isolation of entomopathogenic nematodes and control of ...

    African Journals Online (AJOL)

    Jaime Ruiz

    This study aimed to isolate native entomopathogenic nematodes (EPN) in the Central Valleys of Oaxaca and to determine their potential for control of white grub (Phyllophaga vetula Horn). Fifty-five (55) soil samples were collected in 13 communities in the period August to October 2008 and 29.1% of these were found ...

  3. Evolution of embryonic development in nematodes

    Directory of Open Access Journals (Sweden)

    Schulze Jens

    2011-09-01

    Full Text Available Abstract Background Nematodes can be subdivided into basal Enoplea (clades 1 and 2 and more derived Chromadorea (clades 3 to 12. Embryogenesis of Caenorhabditis elegans (clade 9 has been analyzed in most detail. Their establishment of polarity and asymmetric cleavage requires the differential localization of PAR proteins. Earlier studies on selected other nematodes revealed that embryonic development of nematodes is more diverse than the essentially invariant development of C. elegans and the classic study object Ascaris had suggested. To obtain a more detailed picture of variations and evolutionary trends we compared embryonic cell lineages and pattern formation in embryos of all 12 nematode clades. Methods The study was conducted using 4-D microscopy and 3-D modeling of developing embryos. Results We found dramatic differences compared to C. elegans in Enoplea but also considerable variations among Chromadorea. We discovered 'Polarity Organizing Centers' (POCs that orient cleavage spindles along the anterior-posterior axis in distinct cells over consecutive cell generations. The resulting lineally arranged blastomeres represent a starting point for the establishment of bilateral symmetry within individual lineages. We can discern six different early cleavage types and suggest that these variations are due to modifications in the activity of the POCs in conjunction with changes in the distribution of PAR proteins. In addition, our studies indicate that lineage complexity advanced considerably during evolution, that is we observe trends towards an increase of somatic founder cells, from monoclonal to polyclonal lineages and from a variable (position-dependent to an invariable (lineage-dependent way of cell fate specification. In contrast to the early phase of embryogenesis, the second half ('morphogenesis' appears similar in all studied nematodes. Comparison of early cleavage between the basal nematode Tobrilus stefanskii and the tardigrade

  4. Additional file 2: Figure S3. of Interactions between the oomycete Pythium arrhenomanes and the rice root-knot nematode Meloidogyne graminicola in aerobic Asian rice varieties

    OpenAIRE

    Verbeek, R.; Banaay, C.; Sikder, M.; De Waele, D.; Vera Cruz, C.; Gheysen, G.; Höfte, M.; Kyndt, Tina

    2016-01-01

    Pythium arrhenomanes DNA in rice roots expressed as picogram Pythium DNA per nanogram total DNA. Varieties Palawan (A) and IR81413-BB-75-4 (B) quantified with P. arrhenomanes specific and plant specific primers at 2, 10, 20, 45 and 60 days after transplanting in the raised bed experiment. ‘Natural infestation’ = soil taken from field B912 and ‘Natural infestation + P. arrhenomanes’ = B912 soil with additional P. arrhenomanes inoculation. Each treatment has two biological replicates (of three ...

  5. Helminths of Wild Predatory Mammals of Ukraine. Nematodes

    Directory of Open Access Journals (Sweden)

    Varodi E. I.

    2017-06-01

    Full Text Available The article summarizes information on the nematodes parasitic in wild Carnivora of Ukraine. Totally, 50 species of nematodes are known to parasitise carnivorans in the country, 30 species were registered in the present study. Nematodes were found in 14 species of examined hosts from the families Canidae, Mustelidae and Felidae. Maximum diversity of nematodes of carnivorans was observed in Polissia (forest zone in the north of the country and in Kherson Region in the south. Hosts from the family Canidae harboured 19 nematode species; studied species of the Mustelidae were infected with 15 nematode species, 6 of them were also found in Canidae. The wildcat (Felis silvestris Schreber and the lynx (Lynx lynx Linnaeus harboured only two species of nematodes, both are specific parasites of these hosts. The most comprehensive information concerns the nematode communities of the red fox (Vulpes vulpes Linnaeus and the wolf (Canis lupus Linnaeus, with 19 and 9 nematode species found, correspondingly. From 1 to 6 nematode species were found in other species of carnivorans.

  6. Resistência de clones de umezeiro e cultivares de pessegueiro a Meloidogyne incognita (nemata: Heteroderidae Resistance of mume clones and peach tree cultivars to Meloidogyne incognita (nemata: heteroderidae

    Directory of Open Access Journals (Sweden)

    Newton Alex Mayer

    2005-08-01

    Full Text Available O presente estudo teve por objetivo avaliar a reação dos Clones 05; 10 e 15 de umezeiro (Prunus mume Sieb. et Zucc. e das cultivares Okinawa, Aurora-1 e Dourado-1 de pessegueiro [Prunus persica (L. Batsch] a Meloidogyne incognita (Kofoid and White Chitwood, em condições de casa de vegetação. As plantas foram mantidas em vasos de cerâmica contendo uma mistura de solo e areia (1:1, v/v, previamente autoclavada a 121ºC e 1kgf.cm-2 por 2 horas. Aos 60 dias após o plantio, cada planta foi inoculada com 2.000 ovos e juvenis de segundo estádio de Meloidogyne incognita. O experimento foi conduzido em delineamento inteiramente casualizado, com 6 tratamentos (genótipos e 9 repetições. Transcorridos 116 dias após a inoculação, as plantas foram colhidas para avaliação do sistema radicular. Foi possível verificar que o número de galhas por sistema radicular, o número de ovos e juvenis por 10g de raízes e por sistema radicular foi nulo ou praticamente nulo em todos os clones e nas cultivares estudadas, de forma que os respectivos fatores de reprodução foram todos inferiores a 1. Conclui-se que os Clones 05; 10 e 15 de umezeiro, assim como as cultivares Okinawa, Aurora-1 e Dourado-1 de pessegueiro são resistentes a Meloidogyne incognita.The present study had for objective to study the reaction of mume Clones 05, 10 and 15 (Prunus mume Sieb. et Zucc. and 'Okinawa', 'Aurora-1' and 'Dourado-1' peach tree cultivars [Prunus persica (L. Batsch] to Meloidogyne incognita (Kofoid and White Chitwood, in greenhouse conditions. The plants were maintained in ceramic boxes containing a soil-sand mixture (1:1, v/v, previously autoclaved at 121ºC and 1 kgf.cm-2 for 2 hours. On the sixtieth day after planting, each plant was inoculated with 2,000 eggs in the second stage juvenile of Meloidogyne incognita. The experiment was carried out in randomized design with 6 treatments (genotypes and 9 repetitions. After 116 days from inoculation, plants were

  7. Nematóides que parasitam a soja na região de Bauru Nematode parasites of soybean in the Bauru region

    Directory of Open Access Journals (Sweden)

    Luiz Gonzaga E. Lordello

    1956-01-01

    Full Text Available Entre os sérios fatôres que atuam contra a expansão da cultura da soja no Estado de São Paulo, acha-se o representado por nematóides parasitos. Dêstes, os que mais têm atraído a atenção dos cultivadores e fitopatologistas são as espécies formadoras de galhas no sistema radicular (Meloidogyne spp.. O estudo do material atacado coligido em Bauru revelou que, naquela região, três formas se acham envolvidas, a saber : Pratylenchus sp., Meloidogyne incognita (Kofoid & White, 1919 Chitwood, 1949 e M. javanica bauruensis n. subsp. Neste trabalho é estudada a nova subespécie, sendo também apresentadas algumas observações sobre a população de M. incognita.One of the serious detriments to soybean (Glycine max (L. Merr. cultivation in the State of S. Paulo, Brazil, are root-parasitic nematodes. A study of infected material collected at Bauru, where at least two distinct soybean varieties were cultivated, disclosed that three forms were involved: a meadow nematode (Pralylenchus sp. and two root-knot nematodes (Meloidogyne incognita (Kofoid & White, 1919 Chitwood, 1949, and M. javanica bauruensis n. subsp.. Silva, Lordello & Miyasaka (3 published some observations about the resistance of several soybean varieties to the attacks by root-knot nematodes in Campinas. A detailed study of the nematodes involved in those experiments, which were considered as related do M. incognita, has not yet been made. One of the varieties tested, La 41-1219, proved to be resistant, thereby providing promising material for further studies and breeding. Unfortunately, such a variety when planted in Bauru, was severely attacked by a root-knot species, which is identified as M. incognita. Attacks by M. javanica bauruensis was not noted in that variety but was noted in another variety (Abura growing adjacent in the same field. The host preference of those two nematodes was specific and very marked. M. incognita attacked only var. La 41-1219 and M. javanica

  8. Detecção de Meloidogyne enterolobii em mudas de amoreira (Morus nigra L.

    Directory of Open Access Journals (Sweden)

    Vanessa dos Santos Paes-Takahashi

    2015-05-01

    Full Text Available O comércio de mudas sem certificação contribui para disseminação de pragas e doenças, que podem causar sérios danos às plantas cultivadas. Na região de Itapetininga (SP, foram apreendidas, pela equipe da Defesa Agropecuária, mudas de aceroleira, goiabeira e amoreira, comercializadas em caminhões, que apresentavam galhas nas raízes, sintoma típico causado por Meloidogyne spp. A identificação da espécie foi feita através da morfologia da configuração perineal de fêmeas e região labial de machos, bem como através da caracterização do fenótipo enzimático de esterase. Foi constatada a presença de M. enterolobii nas amostras analisadas. Trata-se do primeiro relato do parasitismo de M. enterolobii em mudas de amoreira no mundo.

  9. Reaction of genotypes of lulo (Solanum quitoense Lam. to Meloidogyne spp. under field conditions

    Directory of Open Access Journals (Sweden)

    Claudia Salazar-González

    2017-05-01

    Full Text Available In Colombia, root-knot nematodes Meloidog yne spp. are considered as one of the main constraints in lulo crop production . These nematodes can cause root damage resulting in low production. The aim of this study was to evaluate under field conditions the reaction of 16 genotypes of lulo, Solanum quitoense Lam. (Solanaceae, of the Castilla variety and the species S. hirtum Vahl., previously selected in a greenhouse experiment and categorized as moderately resistant and resistant to the attack by Meloidog yne sp. A chemical treatment and a control treatment, the latter based on the most susceptible genotype in greenhouse experiments were also included. The experiment was conducted in a lulo grove naturally infested with root-knot nematodes under a randomized complete block design with three replications and nine plants per experimental unit. The response variables were incidence, severity and yield. The incidence was higher than 80 % in all cases, but the severity varied because of their genetic condition; BR03 and BR01 being genotypes with lower rates of severity, with values of 1.0 % and 0.8 %, respectively. The yield analysis of variance showed significant differences, indicating that genotypes SQBR01 and SQLF04, reached the highest values with 4.77 and 4.74 t/ha in a total of three harvests.

  10. Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species.

    Science.gov (United States)

    Ulloa, M; Wang, C; Saha, S; Hutmacher, R B; Stelly, D M; Jenkins, J N; Burke, J; Roberts, P A

    2016-04-01

    Chromosome substitution (CS) lines in plants are a powerful genetic resource for analyzing the contribution of chromosome segments to phenotypic variance. In this study, a series of interspecific cotton (Gossypium spp.) CS lines were used to identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode or fungal disease resistance traits. The CS lines were developed in the G. hirsutum L. TM-1 background with chromosome or chromosome segment substitutions from G. barbadense L. Pima 3-79 or G. tomentosum. Root-knot nematode (Meloidogyne incognita) and fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) (races 1 and 4) resistance alleles and quantitative trait loci (QTL) previously placed on cotton chromosomes using SSR markers in two interspecific recombinant inbred line populations were chosen for testing. Phenotypic responses of increased resistance or susceptibility in controlled inoculation and infested field assays confirmed the resistance QTLs, based on substitution with the positive or negative allele for resistance. Lines CS-B22Lo, CS-B04, and CS-B18 showed high resistance to nematode root-galling, confirming QTLs on chromosomes 4 and 22 (long arm) with resistance alleles from Pima 3-79. Line CS-B16 had less fusarium race 1-induced vascular root staining and higher percent survival than the TM-1 parent, confirming a major resistance QTL on chromosome 16. Lines CS-B(17-11) and CS-B17 had high fusarium race 4 vascular symptoms and low survival due to susceptible alleles introgressed from Pima 3-79, confirming the localization on chromosome 17 of an identified QTL with resistance alleles from TM1 and other resistant lines. Analyses validated regions on chromosomes 11, 16, and 17 harboring nematode and fusarium wilt resistance genes and demonstrated the value of CS lines as both a germplasm resource for breeding programs and as a powerful genetic analysis tool for determining QTL effects for disease

  11. A model for nematode locomotion in soil

    Science.gov (United States)

    Hunt, H. William; Wall, Diana H.; DeCrappeo, Nicole; Brenner, John S.

    2001-01-01

    Locomotion of nematodes in soil is important for both practical and theoretical reasons. We constructed a model for rate of locomotion. The first model component is a simple simulation of nematode movement among finite cells by both random and directed behaviours. Optimisation procedures were used to fit the simulation output to data from published experiments on movement along columns of soil or washed sand, and thus to estimate the values of the model's movement coefficients. The coefficients then provided an objective means to compare rates of locomotion among studies done under different experimental conditions. The second component of the model is an equation to predict the movement coefficients as a function of controlling factors that have been addressed experimentally: soil texture, bulk density, water potential, temperature, trophic group of nematode, presence of an attractant or physical gradient and the duration of the experiment. Parameters of the equation were estimated by optimisation to achieve a good fit to the estimated movement coefficients. Bulk density, which has been reported in a minority of published studies, is predicted to have an important effect on rate of locomotion, at least in fine-textured soils. Soil sieving, which appears to be a universal practice in laboratory studies of nematode movement, is predicted to negatively affect locomotion. Slower movement in finer textured soils would be expected to increase isolation among local populations, and thus to promote species richness. Future additions to the model that might improve its utility include representing heterogeneity within populations in rate of movement, development of gradients of chemical attractants, trade-offs between random and directed components of movement, species differences in optimal temperature and water potential, and interactions among factors controlling locomotion.

  12. Association of nematodes and dogwood cankers.

    Science.gov (United States)

    Self, L H; Bernard, E C

    1994-03-01

    Dogwood canker is a serious production problem of unknown etiology. From May 1985 through April 1989, cankers from 290 flowering dogwood trees in 15 separate nurseries were sampled for nematodes. Seventy-three percent (213) of the cankers contained nematodes. Panagrolaimus rigidus (Schneider) Thorne (115/290) and Aphelenchoides spp. (91/290) were the most frequently collected taxa. Panagrolaimus rigidus was reared on 2% water agar with unidentified bacteria as the food source. Aphelenchoides spp. were reared in antibiotic-amended agar culture with the fungus Glomerella cingulata (Stoneman) Spauld. &Schrenk as a food source. Repeated attempts to culture Aphelenchoides spp. on dogwood callus tissue were unsuccessful. Artificially created stem wounds inoculated with combinations of Aphelenchoides spp. and P. rigidus callused completely in 60 days with no indication of canker development. Very low numbers of nematodes were recovered from inoculated trees, but P. rigidus and one Aphelenchoides sp. were efficient dispersers and occurred in treatments other than those in which they were inoculated.

  13. Assaying environmental nickel toxicity using model nematodes

    Science.gov (United States)

    Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  14. Assaying environmental nickel toxicity using model nematodes.

    Directory of Open Access Journals (Sweden)

    David Rudel

    Full Text Available Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water, we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  15. Assaying environmental nickel toxicity using model nematodes.

    Science.gov (United States)

    Rudel, David; Douglas, Chandler D; Huffnagle, Ian M; Besser, John M; Ingersoll, Christopher G

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  16. Levantamento de Meloidogyne exigua na cultura da seringueira em São José do Rio Claro, MT, Brasil

    Directory of Open Access Journals (Sweden)

    Bernardo Eduardo Roberto de Almeida

    2003-01-01

    Full Text Available Este trabalho foi realizado com o objetivo de efetuar um levantamento da ocorrência de Meloidogyne exigua em seringueira em São José do Rio Claro, MT. Foram amostradas 191 propriedades agrícolas, totalizando cerca de 18.000ha. Os nematóides foram identificados no Laboratório de Nematologia do Departamento de Fitossanidade da FCAV/UNESP, em Jaboticabal, SP. Foram encontrados níveis populacionais de M. exigua entre 0 e 61.824 juvenis/5g de raízes.

  17. Extracting DNA of nematodes communities from Argentine Pampas agricultural soils

    Directory of Open Access Journals (Sweden)

    Eduardo A. Mondino

    2015-06-01

    Full Text Available We examined four strategies (Tris/EDTA, sodium dodecyl sulfate, Chelex 100 resin and cetyltrimethylammonium bromide -CTAB- for extracting nucleic acid (DNA from communities of nematodes. Nematodes were isolated from an agricultural area under different management of long-term crop rotation experiment from Argentina during three seasons. After DNA extraction, Polymerase Chain Reaction-amplifications were performed and considered as indicators of successful DNA extraction. The CTAB combined with proteinase K and phenol-chloroform-isoamyl alcohol was the unique successful method because positive amplifications were obtained by using both eukaryotic and nematode specific primers. This work could contribute to biodiversity studies of nematodes on agroecosystems.

  18. Nematóide de galha em rabanete: suscetibilidade de cultivares e patogenicidade Root-knot nematode: cultivars reaction and damage to radish

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Rossi

    2004-03-01

    Full Text Available Pesquisaram-se as reações de 11 cultivares de rabanete a Meloidogyne javanica e sua patogenicidade a uma dessas cultivares. No estudo de reações, os tratamentos/cultivares foram 'Comprido Branco', 'Crimson Gigante', 'Ponta Branca', 'Comprido Vermelho', 'Serrano', 'Gigante Wurzburgo', 'Saxa', 'Redondo Vermelho', 'Redondo Gigante', 'Cometo' e 'Akamaru Hatsuka'. Determinaram-se os índices de galhas (IG e de massas de ovos (IMO, o número de nematóides no sistema radicular (NSR e por grama de raiz (NGR e o fator de reprodução (FR 53 dias após a inoculação artificial com 2.000 ovos do parasito. Em outro experimento, avaliaram-se os efeitos de três densidades populacionais do nematóide [0, 500 (nível populacional baixo e 10.000 (nível populacional alto ovos/planta] sobre as massas frescas e secas de túberas e de parte aérea da cultivar 'Redondo Gigante', 39 dias após a inoculação. Os resultados mostraram que todas as cultivares permitiram a reprodução de M. javanica, sendo portanto consideradas suscetíveis. Valores de IG e IMO foram maiores ou iguais a 2,5 e os de FR, maiores do que 8,0 para todas as cultivares estudadas. O parasito causou diminuição significativa nas massas frescas e secas de túberas e de partes aéreas nos dois níveis populacionais estudados comparados com o controle não inoculado. As médias dos tratamentos contendo níveis populacionais baixo e alto do nematóide também diferiram estatisticamente entre si, comprovando-se, assim, a sua ação patogênica sobre a cultivar avaliada.Experiments were conducted under greenhouse conditions to determine the reaction of eleven radish (Raphanus sativus cultivars to Meloidogyne javanica and the pathogenicity of this nematode to a previously selected cultivar. The cultivars tested were 'Comprido Branco', 'Crimson Gigante', 'Ponta Branca', 'Comprido Vermelho', 'Serrano', 'Gigante Wurzburgo', 'Saxa', 'Redondo Vermelho', 'Redondo Gigante', 'Cometo' and 'Akamaru

  19. Evaluación biológica del manejo de picudos y nematodos fitopatógenos en plátano (Musa AAB Biological evaluation of the management of borers and phytopathogenic nematodes of plantain (Musa AAB

    Directory of Open Access Journals (Sweden)

    Carolina González Cardona

    2009-10-01

    Full Text Available El trabajo se desarrolló en la granja Montelindo, municipio de Palestina (Caldas a 5° 05' N y 75° 40' O, a 1010 m.s.n.m., 23.5 °C, precipitación anual de 2100 mm y humedad relativa de 76%, con el fin de generar información sobre el manejo de picudos y nematodos fitoparásitos del plátano. Se usó un diseño en bloques completos al azar con cuatro tratamientos por bloque, tres repeticiones y 24 plantas por repetición. Para el manejo de los picudos se hicieron aplicaciones de Carbofurán, Beauveria bassiana y Metarhizium anisopliae en trampas tipo columna. Para el control de nematodos se hicieron aplicaciones en el suelo de Carbofurán y dos cepas comerciales de Paecilomyces lilacinus. Se evaluaron el número de adultos de picudos en trampas, la infección de estos por los hongos empleados y la población de nematodos en suelo y raíces. Se encontró que las trampas tratadas con Carbofurán fueron significativamente más efectivas para la captura de insectos. En laboratorio se estableció que M. anisopliae tuvo una mejor capacidad para infectar adultos del insecto en el campo. La población de nematodos fue menor en suelo y raíces de las plantas tratadas con Carbofurán. Paecilomyces lilacinus no fue efectivo para reducir las poblaciones de nematodos. Los géneros de nematodos predominantes fueron Radopholus, Pratylenchus, Meloidogyne y Helicotylenchus.This work was carried out at the ‘Montelindo’ farm, municipality of Palestina (Department of Caldas, Colombia, located at 5° 05' N and 75° 40' W, at 1010 m.a.s.l., 23.5 °C, with 2100 mm of annual rainfall, and relative humidity of 76%, in order to generate information on the management of borers and parasitic nematodes of the plantain. A completely randomised block experimental design was used, with four treatments per block, three replicates and 24 plants per replicate. For the management of borers, applications of Carbofuran, Beauveria bassiana and Metarhizium anisopliae were made

  20. Evaluation of root-knot nematode disease control and plant growth promotion potential of biofertilizer Ning shield on Trichosanthes kirilowii in the field.

    Science.gov (United States)

    Jiang, Chun-Hao; Xie, Ping; Li, Ke; Xie, Yue-Sheng; Chen, Liu-Jun; Wang, Jin-Suo; Xu, Quan; Guo, Jian-Hua

    2017-11-11

    Biofertilizer Ning shield was composed of different strains of plant growth promotion bacteria. In this study, the plant growth promotion and root-knot nematode disease control potential on Trichosanthes kirilowii in the field were evaluated. The application of Ning shield significantly reduced the diseases severity caused by Meloidogyne incognita, the biocontrol efficacy could reached up to 51.08%. Ning shield could also promote the growth of T. kirilowii in the field by increasing seedling emergence, height and the root weight. The results showed that the Ning shield could enhance the production yield up to 36.26%. Ning shield could also promote the plant growth by increasing the contents of available nitrogen, phosphorus, potassium and organic matter, and increasing the contents of leaf chlorophyll and carotenoid pigment. Moreover, Ning shield could efficiently enhance the medicinal compositions of Trichosanthes, referring to the polysaccharides and trichosanthin. Therefore, Ning shield is a promising biofertilizer, which can offer beneficial effects to T. kirilowii growers, including the plant growth promotion, the biological control of root-knot disease and enhancement of the yield and the medicinal quality. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  1. Geostatistical modeling of the spatial variability and risk areas of southern root-knot nematodes in relation to soil properties.

    Science.gov (United States)

    Ortiz, B V; Perry, C; Goovaerts, P; Vellidis, G; Sullivan, D

    2010-05-01

    Identifying the spatial variability and risk areas for southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] (RKN) is key for site-specific management (SSM) of cotton (Gossypium hirsutum L.) fields. The objectives of this study were to: (i) determine the soil properties that influence RKN occurrence at different scales; and (ii) delineate risk areas of RKN by indicator kriging. The study site was a cotton field located in the southeastern coastal plain region of the USA. Nested semivariograms indicated that RKN samples, collected from a 50×50 m grid, exhibited a local and regional scale of variation describing small and large clusters of RKN population density. Factorial kriging decomposed RKN and soil properties variability into different spatial components. Scale dependent correlations between RKN data showed that the areas with high RKN population remained stable though the growing season. RKN data were strongly correlated with slope (SL) at local scale and with apparent soil electrical conductivity deep (EC(a-d)) at both local and regional scales, which illustrate the potential of these soil physical properties as surrogate data for RKN population. The correlation between RKN data and soil chemical properties was soil texture mediated. Indicator kriging (IK) maps developed using either RKN, the relation between RKN and soil electrical conductivity or a combination of both, depicted the probability for RKN population to exceed the threshold of 100 second stage juveniles/100 cm(3) of soil. Incorporating EC(a-d) as soft data improved predictions favoring the reduction of the number of RKN observations required to map areas at risk for high RKN population.

  2. A harpin elicitor induces the expression of a coiled-coil nucleotide binding leucine rich repeat (CC-NB-LRR) defense signaling gene and others functioning during defense to parasitic nematodes.

    Science.gov (United States)

    Aljaafri, Weasam A R; McNeece, Brant T; Lawaju, Bisho R; Sharma, Keshav; Niruala, Prakash M; Pant, Shankar R; Long, David H; Lawrence, Kathy S; Lawrence, Gary W; Klink, Vincent P

    2017-12-01

    The bacterial effector harpin induces the transcription of the Arabidopsis thaliana NON-RACE SPECIFIC DISEASE RESISTANCE 1/HARPIN INDUCED1 (NDR1/HIN1) coiled-coil nucleotide binding leucine rich repeat (CC-NB-LRR) defense signaling gene. In Glycine max, Gm-NDR1-1 transcripts have been detected within root cells undergoing a natural resistant reaction to parasitism by the syncytium-forming nematode Heterodera glycines, functioning in the defense response. Expressing Gm-NDR1-1 in Gossypium hirsutum leads to resistance to Meloidogyne incognita parasitism. In experiments presented here, the heterologous expression of Gm-NDR1-1 in G. hirsutum impairs Rotylenchulus reniformis parasitism. These results are consistent with the hypothesis that Gm-NDR1-1 expression functions broadly in generating a defense response. To examine a possible relationship with harpin, G. max plants topically treated with harpin result in induction of the transcription of Gm-NDR1-1. The result indicates the topical treatment of plants with harpin, itself, may lead to impaired nematode parasitism. Topical harpin treatments are shown to impair G. max parasitism by H. glycines, M. incognita and R. reniformis and G. hirsutum parasitism by M. incognita and R. reniformis. How harpin could function in defense has been examined in experiments showing it also induces transcription of G. max homologs of the proven defense genes ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1), TGA2, galactinol synthase, reticuline oxidase, xyloglucan endotransglycosylase/hydrolase, alpha soluble N-ethylmaleimide-sensitive fusion protein (α-SNAP) and serine hydroxymethyltransferase (SHMT). In contrast, other defense genes are not directly transcriptionally activated by harpin. The results indicate harpin induces pathogen associated molecular pattern (PAMP) triggered immunity (PTI) and effector-triggered immunity (ETI) defense processes in the root, activating defense to parasitic nematodes. Copyright © 2017. Published by Elsevier

  3. HERANÇA DA RESISTÊNCIA DE MILHO A MELOIDOGYNE JAVANICA

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    SAWAZAKI EDUARDO

    1998-01-01

    Full Text Available Duas linhagens de milho, resistente (IAC Ip 365-4-1 e suscetível (IAC Ip 48-5-3 a Meloidogyne javanica, suas gerações F1, F2 e retrocruzamentos, bem como os cruzamentos recíprocos, foram avaliados em dois ensaios em casa de vegetação, em 1989/90 e 1992, em Campinas, para estudar a herança da resistência a M. javanica. Utilizou-se o delineamento inteiramente casualizado com número de repetição maior nas gerações segregantes, parcelas de uma planta por vaso plástico com 500 cm3 de areia fina, previamente tratada com brometo de metila e adubada com NPK. Cinco dias após a germinação das sementes, cada vaso foi inoculado com 5.000 ovos e larvas de M. javanica. Aos 70 e aos 60 dias após a inoculação, respectivamente, nos experimentos 1 e 2, avaliaram-se o índice de massa de ovos, o número de ovos por grama de raiz e o fator de reprodução. Não foram observadas diferenças entre os cruzamentos recíprocos. O comportamento da média do F1, a distribuição de freqüência da população F2 e a segregação monofatorial indicaram que a resistência a M. javanica da linhagem IAC Ip 365-4-1 se deve a um gene dominante associado a um pequeno efeito de polígenes.

  4. EFECTO DE POBLACIONES DE Meloidogyne sp. EN EL DESARROLLO Y RENDIMIENTO DEL TOMATE

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    Wilber Salazar-Ant\\u00F3n

    2013-01-01

    Full Text Available El objetivo de este trabajo fue determinar el efecto de la población inicial de Meloidogyne sp. en el cultivo del tomate. El estudio se realizó en León, Nicaragua en el año 2011. Las variables medidas fueron número de nematodos al trasplante y al momento de la cosecha, altura de la planta al momento de la madurez fisiológica y el rendimiento en kilogramos. La extracción de nematodos se realizó mediante el método de Baermann modificado. En el estudio, la densidad inicial (Pi presentó una correlación lineal positiva con la densidad final (Pf. Sin embargo, se observó que cuando la Pi era igual a 400 nematodos/100 g de suelo, el factor de reproducción se incrementaba a 3,64; por el contrario, cuando la Pi era igual a 700 nematodos/100 g de suelo, el factor de reproducción se reducía a 2,48. La Pi se correlacionó inversamente con el peso de frutos y altura de las plantas. Plantas con 200 nematodos/100 g de suelo presentaban peso de frutos de 2,19 kg y altura de 153,20 cm en comparación con 0,93 kg y 135,24 cm en plantas con 600 nematodos/100 g de suelo. Existió una correlación positiva entre Pi y Pf de Meloidogy- ne sp. en el tomate. Las poblaciones de este nematodo, se correlacionaron inversamente con las variables altura y peso de los frutos.

  5. Transgenesis in parasitic nematodes: building a better array

    OpenAIRE

    Lok, James B.

    2009-01-01

    In spite of recent progress in the development of transgenesis in parasitic nematodes, several impediments remain before this methodology can become a practical and widely employed tool in parasitology. Recently published studies on transgenesis in the necromenic nematode Pristionchus pacificus from the laboratory of Ralf Sommer highlight several leads that might be valuable as efforts to refine current systems in obligate parasites go forward.

  6. Microsatellite diversity of isolates of the parasitic nematode Haemonchus contortus

    NARCIS (Netherlands)

    Otsen, M.; Plas, M. E.; Lenstra, J. A.; Roos, M. H.; Hoekstra, R.

    2000-01-01

    The alarming development of anthelmintic resistance in important gastrointestinal nematode parasites of man and live-stock is caused by selection for specific genotypes. In order to provide genetic tools to study the nematode populations and the consequences of anthelmintic treatment, we isolated

  7. Cyst nematode-induced changes in plant development

    NARCIS (Netherlands)

    Goverse, A.

    1999-01-01

    This thesis describes a first attempt to investigate the biological activity of cyst nematode secretions on plant cell proliferation and the molecular mechanisms underlying feeding cell development in plant roots upon cyst nematode infection.

    To investigate the role of

  8. The cyst nematodes Heterodera and Globodera species in Egypt

    Science.gov (United States)

    Information concerning the occurrence and distribution of the cyst nematodes (Heterodera spp. and Globodera spp.) in Egypt is important to assess their potential to cause economic damage to many crop plants. A nematode survey was conducted in Alexandria, El Behera and Sohag governorates during 2012-...

  9. Occurence of plant parasitic nematodes and factors that enhance ...

    African Journals Online (AJOL)

    Plant parasitic nematodes remain a major challenge to crop production that has hitherto received minmum research attention in sub-Saharan Africa. This paper gives the diversity of nematode genera and species associated with cereal crops and indicates the possibility of nemadode population build up due to production ...

  10. Free-living Marine Nematodes. Part 1 British Enoplids

    African Journals Online (AJOL)

    This is the first of three volumes dealing with the most abundant group of animals on the sea-bed and sea-shore, the free-living marine nematodes, and is devoted to those marine nematodes belonging to the subclass Enoplia. Separate volumes will deal with the orders Chromadorida and. Monhysterida. To most marine ...

  11. Evaluation of fallow and cover crops for nematode suppression in ...

    African Journals Online (AJOL)

    A study was conducted in three agroecological zones of south-western Nigeria to evaluate the effect of siam weed (Chromolaena odorata) and mucuna (Mucuna utilis) cover/fallow crops on plant-parasitic nematode population. The natural bush regrowth was used as control. Plant-parasitic nematodes were identified and ...

  12. Soybean lines evaluated for resistance to reniform nematode

    Science.gov (United States)

    Seventy-four wild and domestic soybean (Glycine max and G. soja) lines were evaluated for resistance to reniform nematode (Rotylenchulus reniformis) in growth chamber tests with a day length of 16 hours and temperature held constant at 28 C. Several entries for which reactions to reniform nematode w...

  13. Screening of in vitro derived mutants of banana against nematodes ...

    African Journals Online (AJOL)

    The rest of the mutants namely Ro Im V4 6-1-2 and Si Im V4 6-2-5 were found to be susceptible to nematodes. The resistant and moderately resistant mutants of banana could be further used in breeding programmes as well as being recognized as potential cultivars of commerce. Key words: Banana, nematode, resistance, ...

  14. Molecular and genetic analyses of potato cyst nematode resistance loci

    NARCIS (Netherlands)

    Bakker, E.H.

    2003-01-01

    This thesis describes the genomic localisation and organisation of loci that harbour resistance to the potato cyst nematode species Globodera pallida and G. rostochiensis . Resistance to the potato cyst nematodes G. pallida and G. rostochiensis is an important aspect in potato breeding. To gain

  15. A Survey of Nematode Infection in Oreochromis niloticus (L ...

    African Journals Online (AJOL)

    The incidence and intensity of nematode infection was investigated in Nile tilapia Oreochromis niloticus from Lake Kyoga, Uganda and 11% of the 406 fish examined were parasitized by nematodes of the genus Contracaecum. The prevalence of these parasites was greatest in the smallest and largest size classes, but this ...

  16. Book review: Systematics of Cyst Nematodes (Nematoda: Heteroderinae)

    Science.gov (United States)

    The cyst nematodes are an important group of plant-parasitic nematodes that cause billions of dollars in economic damage to crops every year. This article reviews a recently published, two-volume monograph that describes the morphological and molecular characteristics of these agriculturally signif...

  17. Prevalence of trichostrongylid nematode in sheeps in Benin City ...

    African Journals Online (AJOL)

    Parasitism of Trichostrongylid nematode is a world-wide problem for both small and large scale farmers and is a great threat to the livestock industry and also a major constraint to the wellbeing and productive performance of ruminant animals. This study was carried out to determine the effect of Trichostrongylid nematode in ...

  18. Nematode community structure as a bioindicator in environmental monitoring

    NARCIS (Netherlands)

    Bongers, T.; Ferris, H.

    1999-01-01

    Four of every five multicellular animals on the planet are nematodes. They occupy any niche that provides an available source of organic carbon in marine, freshwater and terrestrial environments. Nematodes vary in sensitivity to pollutants and environmental disturbance. Recent development of indices

  19. Epidemiological study on abomasal nematodes in slaughtered small ...

    African Journals Online (AJOL)

    Gastrointestinal nematodes are one of the major causes of productivity losses in small ruminants in sub-Saharan Africa. A study was carried out to evaluate the prevalence, worm burden of abomasal nematodes and associated faecal egg counts (FEC) of small ruminants slaughtered from November, 2011 to October, 2012.

  20. Freshwater nematodes from South Africa. 4. The genus Monhystera ...

    African Journals Online (AJOL)

    Freshwater nematodes from South Africa. 4. The genus Monhystera Bastian, 1865. A.P. Joubert and J. Heyns. Department of Zoology. Rand Afrikaans University. During a survey of freshwater nematodes in South Africa, five species of Monhystera Bastian, 1865, were encountered. The five species, three of which are new to ...

  1. Nematode effector proteins: an emerging paradigm of parasitism

    Science.gov (United States)

    Phytonematodes use a stylet and secreted effectors to invade host tissues and extract nutrients to support their growth and development. The molecular function of nematode effectors is currently the subject of intense investigation. In this review, we summarize our current understanding of nematode ...

  2. Prevalence of common gastro-intestinal nematode infections in ...

    African Journals Online (AJOL)

    ACSS

    (Hansen and Perry, 1994). Furthermore, nematode egg counting per gramme of faeces (epg) was done on the same samples using the modified McMaster technique, as described by Hansen and. Perry (1994). Identification of third stage nematode larvae. About three grammes of faeces were taken from each sample.

  3. Occurrence and prevalence of nematodes in yam fields from four ...

    African Journals Online (AJOL)

    Nematodes is one of the major biotic constraints affecting profitable yam production throughout Nigeria. They affect yams both in the field and in storage thus threatening food security and economic deprivation to growers and their households. The research work identified the types, frequency and population of nematodes ...

  4. occurrence of plant parasitic nematodes and factors that enhance ...

    African Journals Online (AJOL)

    Administrator

    Plant parasitic nematodes remain a major challenge to crop production that has hitherto received minmum research attention in sub-Saharan Africa. This paper gives the diversity of nematode genera and species associ- ated with cereal crops and indicates the possibility of nemadode population build up due to production ...

  5. Native nematodes as new bio-insecticides for cranberries

    Science.gov (United States)

    In the summer of 2015, an effort was made in central Wisconsin to find an entomopathogenic nematode capable controlling Wisconsin’s cranberry pests. Using a standard baiting method, a nematode of the Oscheius genus was collected from the mossy, sandy, peat-filled soils of a wild cranberry marsh. Thi...

  6. Plants producing pyrrolizidine alkaloids: sustainable tools for nematode management?

    NARCIS (Netherlands)

    Thoden, T.C.; Boppre, M.

    2010-01-01

    1,2-dehydropyrrolizidine ester alkaloids (pyrrolizidine alkaloids; PAs) are a class of secondary plant metabolites found in hundreds of plant species. In vitro, PAs are known to affect plant-parasitic nematodes. Thus, PA-producing plants might be used in nematode management. So far, however,

  7. Control of the peachtree borer using beneficial nematodes

    Science.gov (United States)

    The peachtree borer, Synanthedon exitiosa, is a major pest of peaches and other stone fruits. Our research indicates that entomopathogenic nematodes, also known as beneficial nematodes, can be used effectively to control the insect. We conducted replicated experiments in randomized block designs ov...

  8. KETAHANAN BEBERAPA VARIETAS UNGGUL KEDELAI TERHADAP NEMATODA PURU AKAR (Meloidogyne incognita

    Directory of Open Access Journals (Sweden)

    Wayan Sukanaya

    2001-07-01

    Full Text Available The aims of this experiment are to find the varieties of soybean which are resistant against root-knot nematode (M. incognita and to determine its attractancy toward the roots of resistant and susceptible soybean varieties. The experiment was divided into two parts, both parts using Completely Randomized Design. The first part was designed to determine the resistance and the second one to determine attractancy. The experiments were conducted in a green house and Plant Pest and Disease Laboratory, Faculty of Agriculture, Udayana University for 5 months. Of the 23 varieties of soybean tested against M. incognita showed that two varieties (Petek and Rinjani were moderately resistant, 11 varieties were moderately susceptible and 10 varieties were found to be susceptible. However, none of variety was resistant. While on attractancy of root test of moderately resistant and susceptible variety it was found that M. incognita was more attracted to root of susceptible variety (Ringgit than to moderately resistant variety (Petek. Key words: soybean, resistance, root-knot nematode

  9. Transgenesis in the parasitic nematode Strongyloides ratti.

    Science.gov (United States)

    Li, Xinshe; Shao, Hongguang; Junio, Ariel; Nolan, Thomas J; Massey, Holman C; Pearce, Edward J; Viney, Mark E; Lok, James B

    2011-10-01

    Strongyloides and related genera are advantageous subjects for transgenesis in parasitic nematodes, primarily by gonadal microinjection as has been used with Caenorhabditis elegans. Transgenesis has been achieved in Strongyloides stercoralis and in Parastrongyloides trichosuri, but both of these lack well-adapted, conventional laboratory hosts in which to derive transgenic lines. By contrast, Strongyloides ratti develops in laboratory rats with high efficiency and offers the added advantages of robust genomic and transcriptomic databases and substantial volumes of genetic, developmental and immunological data. Therefore, we evaluated methodology for transgenesis in S. stercoralis as a means of transforming S. ratti. S. stercoralis-based GFP reporter constructs were expressed in a proportion of F1 transgenic S. ratti following gonadal microinjection into parental free-living females. Frequencies of transgene expression in S. ratti, ranged from 3.7% for pAJ09 to 6.8% for pAJ20; respective frequencies for these constructs in S. stercoralis were 5.6% and 33.5%. Anatomical patterns of transgene expression were virtually identical in S. ratti and S. stercoralis. This is the first report of transgenesis in S. ratti, an important model organism for biological investigations of parasitic nematodes. Availability of the rat as a well-adapted laboratory host will facilitate derivation of transgenic lines of this parasite. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Arrested larval development in cattle nematodes.

    Science.gov (United States)

    Armour, J; Duncan, M

    1987-06-01

    Most economically important cattle nematodes are able to arrest their larval development within the host - entering a period of dormancy or hypobiosis. Arrested larvae have a low death rate, and large numbers can accumulate in infected cattle during the grazing season. Because of this, outbreaks of disease caused by such nematodes can occur at times when recent infection with the parasites could not have occurred, for example during winter in temperature northern climates when cattle are normally housed. The capacity to arrest is a heritable trait. It is seen as an adaptation by the parasite to avoid further development to its free-living stages during times when the climate is unsuitable for free-living survival. But levels of arrestment can vary markedly in different regions, in different cattle, and under different management regimes. Climatic factors, previous conditioning, host immune status, and farm management all seem to affect arrestment levels. In this article, James Armour and Mary Duncan review the biological basis of the phenomenon, and discuss the apparently conflicting views on how it is controlled.

  11. Some nematodes of freshwater fishes in Venezuela.

    Science.gov (United States)

    Moravec, F; Prouza, A; Royero, R

    1997-01-01

    The present paper comprises a systematic survey of nematodes found in 88 specimens of 24 species of freshwater fishes in Venezuela in 1992 and 1994. The following 13 species of nematodes were recorded: Adults; Guyanema longispiculum Moravec, Prouza et Royero, 1996, Guyanema sp., Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas et Pereira, 1928, P. (S.) krameri (Petter, 1974) comb. n., P.(S.) pintoi (Kohn et Fernandes, 1988) comb, n., Procamallanus (Spirocamallanus) sp., Raphidascaris (Sprentascaris) mahnerti (Petter et Cassone, 1984). Larvae: Anisakidae gen. sp., Brevimulticaecum sp., Contracaecum sp. Type 1, Contracaecum sp. Type 2, Contracaecum sp. Type 3, Eustrongylides sp. All these parasites are reported from Venezuela for the first time and all findings represent new host records. Brevimulticaecum larvae are reported from fishes for the first time. Almost all parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. A new name, Terranova diazungriai nom.nov. is proposed for T. caballeroi Díaz-Ungría, 1968 (a junior homonym of T. caballeroi Barus et Coy Otero, 1966).

  12. Experimental Evolution withCaenorhabditisNematodes.

    Science.gov (United States)

    Teotónio, Henrique; Estes, Suzanne; Phillips, Patrick C; Baer, Charles F

    2017-06-01

    The hermaphroditic nematode Caenorhabditis elegans has been one of the primary model systems in biology since the 1970s, but only within the last two decades has this nematode also become a useful model for experimental evolution. Here, we outline the goals and major foci of experimental evolution with C. elegans and related species, such as C . briggsae and C. remanei , by discussing the principles of experimental design, and highlighting the strengths and limitations of Caenorhabditis as model systems. We then review three exemplars of Caenorhabditis experimental evolution studies, underlining representative evolution experiments that have addressed the: (1) maintenance of genetic variation; (2) role of natural selection during transitions from outcrossing to selfing, as well as the maintenance of mixed breeding modes during evolution; and (3) evolution of phenotypic plasticity and its role in adaptation to variable environments, including host-pathogen coevolution. We conclude by suggesting some future directions for which experimental evolution with Caenorhabditis would be particularly informative. Copyright © 2017 Teotónio et al.

  13. Vertebrate herbivores influence soil nematodes by modifying plant communities.

    Science.gov (United States)

    Veen, G F; Olff, Han; Duyts, Henk; van der Putten, Wim H

    2010-03-01

    Abiotic soil properties, plant community composition, and herbivory all have been reported as important factors influencing the composition of soil communities. However, most studies thus far have considered these factors in isolation, whereas they strongly interact in the field. Here, we study how grazing by vertebrate herbivores influences the soil nematode community composition of a floodplain grassland while we account for effects of grazing on plant community composition and abiotic soil properties. Nematodes are the most ubiquitous invertebrates in the soil. They include a variety of feeding types, ranging from microbial feeders to herbivores and carnivores, and they perform key functions in soil food webs. Our hypothesis was that grazing affects nematode community structure and composition through altering plant community structure and composition. Alternatively, we tested whether the effects of grazing may, directly or indirectly, run via changes in soil abiotic properties. We used a long-term field experiment containing plots with and without vertebrate grazers (cattle and rabbits). We compared plant and nematode community structure and composition, as well as a number of key soil abiotic properties, and we applied structural equation modeling to investigate four possible pathways by which grazing may change nematode community composition. Aboveground grazing increased plant species richness and reduced both plant and nematode community heterogeneity. There was a positive relationship between plant and nematode diversity indices. Grazing decreased the number of bacterial-feeding nematodes, indicating that in these grasslands, top-down control of plant production by grazing leads to bottom-up control in the basal part of the bacterial channel of the soil food web. According to the structural equation model, grazing had a strong effect on soil abiotic properties and plant community composition, whereas plant community composition was the main determinant of

  14. Mining the secretome of root-knot nematodes for cell wall modifying proteins

    NARCIS (Netherlands)

    Roze, E.H.A.

    2008-01-01

    The products of parasitism genes in nematodes must be secreted to reach their targets at the nematode-plant interface. These nematode secretory proteins are therefore recognised to play an important role in the nematode-plant interaction and as a result have been subject of intense study for years.

  15. Molecular Transducers from Roots Are Triggered in Arabidopsis Leaves by Root-Knot Nematodes for Successful Feeding Site Formation: A Conserved Post-Embryogenic De novo Organogenesis Program?

    Directory of Open Access Journals (Sweden)

    Rocío Olmo

    2017-05-01

    Full Text Available Root-knot nematodes (RKNs; Meloidogyne spp. induce feeding cells (giant cells; GCs inside a pseudo-organ (gall from still unknown root cells. Understanding GCs ontogeny is essential to the basic knowledge of RKN–plant interaction and to discover novel and effective control strategies. Hence, we report for the first time in a model plant, Arabidopsis, molecular, and cellular features concerning ectopic de novo organogenesis of RKNs GCs in leaves. RKNs induce GCs in leaves with irregular shape, a reticulated cytosol, and fragmented vacuoles as GCs from roots. Leaf cells around the nematode enter G2-M shown by ProCycB1;1:CycB1;1(NT-GUS expression, consistent to multinucleated GCs. In addition, GCs nuclei present irregular and varied sizes. All these characteristics mentioned, being equivalent to GCs in root-galls. RKNs complete their life cycle forming a gall/callus-like structure in the leaf vascular tissues resembling auxin-induced callus with an auxin-response maxima, indicated by high expression of DR5::GUS that is dependent on leaf auxin-transport. Notably, induction of leaves calli/GCs requires molecular components from roots crucial for lateral roots (LRs, auxin-induced callus and root-gall formation, i.e., LBD16. Hence, LBD16 is a xylem pole pericycle specific and local marker in LR primordia unexpectedly induced locally in the vascular tissue of leaves after RKN infection. LBD16 is also fundamental for feeding site formation as RKNs could not stablish in 35S::LBD16-SRDX leaves, and likely it is also a conserved molecular hub between biotic and developmental signals in Arabidopsis either in roots or leaves. Moreover, RKNs induce the ectopic development of roots from leaf and root-galls, also formed in mutants compromised in LR formation, arf7/arf19, slr, and alf4. Therefore, nematodes must target molecular signatures to induce post-embryogenic de novo organogenesis through the LBD16 callus formation pathway partially different from those

  16. Radiation disinfection or disinfestation of nematodes, aphids, mites, thrips, and other pests on food plant materials: evaluation for effectiveness and product quality

    International Nuclear Information System (INIS)

    Moy, J.H.; Chinnasri, B.; Sipes, B.S.; Schmitt, D.P.; Hamasaki, R.T.; Mersino, E.F.; Yamakawa, R.M.

    1999-01-01

    Many fresh herbs, ornamental plants, and several varieties of taro grown in Hawaii are infested with various pests such as aphids, mites, thrips, and nematodes. Finding an efficacious quarantine treatment for these commodities is difficult because most cannot tolerate heat or cold, and a suitable chemical treatment is lacking. Irradiation could be a feasible, practical alternative. Quality of these irradiated materials should be studied to help determine if irradiation is a suitable quarantine treatment. Of the ten fresh herbs irradiated with up to 0.70 kGy, five (rosemary, thyme, oregano, parsley, chives) are very tolerant, and show no difference from the controls after two to three weeks at 7 deg. C. Red ginger and four cultivars of heliconia, very attractive ornamental plants, can be irradiated at 0.75 and 0.50 kGy, respectively, and have a vase life of 10 days or more at 21 deg. C. Leafminer in bean plants cannot emerge when irradiated at 0.15 kGy. The nematode, Meloidogyne javanica, which infects taro and ginger, is prevalent in Hawaii. To cause mortality in second stage juveniles (J2), a gamma-radiation dose higher than 4.0 kGy is necessary. Suppression of hatching of egg masses requires doses of 2.0 kGy and above. Galling of tomato plants inoculated with J2 and egg masses decreases when J2 and egg masses were irradiated at 3.25 kGy and above. Heating J2 at 43 deg. C for 10 min before inoculating them into the plants effectively reduces root galling. Synergism was not found between heat treatment (49 deg. C for 10 or 20 min) and irradiation with up to 0.015 kGy, the dose above which sprouting of ginger rhizomes and taro cormels is inhibited. The results suggest that irradiation is promising as a quarantine treatment for selected fresh herbs and ornamental plants, but not for control of nematodes in root crops. (author)

  17. Non-target effect of continuous application of chlorpyrifos on soil microbes, nematodes and its persistence under sub-humid tropical rice-rice cropping system.

    Science.gov (United States)

    Kumar, Upendra; Berliner, J; Adak, Totan; Rath, Prakash C; Dey, Avro; Pokhare, Somnath S; Jambhulkar, Nitiprasad N; Panneerselvam, P; Kumar, Anjani; Mohapatra, Shyamranjan D

    2017-01-01

    Application of pesticide in agricultural fields is "unnecessary evil" for non-target microflora and fauna. Hence, to identify the safer pesticide molecules against non-target microbes, a long-term pesticide experiment was initiated at National Rice Research Institute, Cuttack, India. In the present study, the effect of continuous application of chlorpyrifos (0.5kgha -1 ) in rice fields on non-target groups of soil microbes and nematodes was studied for seven seasons (four wet and three dry seasons) during 2009-2013. Treatments were arranged in a randomized complete block design with four replications of chlorpyrifos-treated (0.5kg a.i. ha -1 ) (CT) and untreated control (UT) plots. During seven seasons of experimentation, regular application of chlorpyrifos had no significant effect on population of heterotrophic aerobic, anaerobic, oligotrophic and copiotrophic bacteria in CT compared to UT, whereas, population of asymbiotic aerobic nitrogen fixer, nitrifiers, denitrifiers, gram positive and spore-forming bacteria were significantly reduced by nearly 0.25-2 fold in CT than UT. However, comparatively less deviation in population of actinomycetes, fungi, phosphate solubilizing and sulfur oxidizing bacteria were observed in CT than UT. Significant interactions were found between effects of chlorpyrifos with time in population dynamics of microbes. In plant parasitic nematode species, Meloidogyne graminicola (RRKN) and Hirschmanniella spp. (RRN), were significantly lower (p<0.01) in CT compared to UT after first year onwards. The overall observation of five years data indicated that the RRKN population showed a decreasing trend (R 2 =0.644) whereas RRN showed increasing trend (R 2 =0.932) in CT. The drastic chlorpyrifos dissipation was noticed after 15 days of application from the initial residue of 0.25mgkg -1 soil, which indicated that chlorpyrifos residue in rice field soil was not persistent and its half-life was found to be 4.02 days. Overall, the present

  18. Nematicide Effect of Various Organic Soil Amendments on Meloidogyne ethiopica Whitehead, 1968, on Potted Vine Plants Efecto Nematicida de Varias Enmiendas Orgánicas Sobre Meloidogyne ethiopica Whitehead, 1968, en Plantas de Vid en Macetas

    Directory of Open Access Journals (Sweden)

    Lucia Rivera

    2008-09-01

    Full Text Available Five organic soil amendments were evaluated for their nematicide effect on root-knot Meloidogyne ethiopica Whitehead, 1968, on potted Vitis vinifera L. var. Chardonnay plants. The amendments included two immature composts: Compost A made with tea (Camellia sinensis (L. Kuntze residues, broiler litter and grape pomace; Compost B made with tea residues, rachis and grape pomace; and separately dried tea residues, grape pomace and broiler litter. These amendments were either incorporated or applied as cover to the substrate in 5 L pots at the beginning of spring. A chemical treatment with the nematicide fenamiphos and a control with substrate only were added for comparisons. The assay was composed of 11 treatments with six replicates, with a grape plant as experimental unit. Seven months later, the assessment of the treatments was carried out based on number of second stage juvenile, nodules, eggs per root gram and reproductive index. Fresh aerial and root plant weight were also measured. The chemical treatment presented the lowest final population of M. ethiopica. When evaluating the nematicide action of the organic amendments: compost A soil-incorporated and both grape pomace and solid dry tea residue as covers obtained low reproductive indexes, similar to the chemical treatment and control (P ≤ 0.05. No differences in aerial fresh weight were determined. However, the chemical treatment showed the smallest root mass as compared to compost B and solid dry tea residues, both as cover.Se realizó un experimento en macetas con plantas enraizadas de Vitis vinífera L. var. Chardonnay para evaluar el efecto nematicida de diferentes enmiendas orgánicas sobre el nematodo agallador Meloidogyne ethiopica Whitehead, 1968. Se usaron dos composts inmaduros: Compost A, elaborado con residuos de té (Camellia sinensis (L. Kuntze, guano de pollo seco y orujo de uva; Compost B, elaborado con residuos de té, escobajo y orujo de uva; y separadamente residuos s

  19. Kemampuan Isolataktinomisetes Menghasilkan Enzim yang Dapatmerusak Kulit Telur Nematoda Puru-Akar Meloidogyne spp.

    Directory of Open Access Journals (Sweden)

    Bambang Rahayu TP

    2009-07-01

    Full Text Available Soil microbes including actinomycetes are known to produce various hydrolytic enzymes and antibiotics that can be used as biological controlling agents nematode. Therefore, surveys conducted in several areas in Yogyakarta, Central Java and East Java, to search for actinomycetes with chitinolytic, proteolytic, and chitino-proteolytic activity. Isolation of Actinomycetes produced 84 isolates, and most was obtained from shrimp head waste (26 isolates. After the selection based on their ability to hydrolyze chitines and protein in the medium, those whith the highest chitin and protein hydrolysis activity, are consecutive PSJ 27, TL 8, and TL 10 isolates. Test results of crude enzyme produced by selected isolates against root-knot nematode eggshell, showed that the isolates that have chitino-proteolytic activity (TL 10, is a highly effective isolate in damage eggshell. There are three types of damage to the nematode eggs. In the young eggs, crude enzyme preparation causing damage on vitelline and chitin layers. In the older eggs, preparation of crude enzyme cause premature hatching.   Sebagian mikrobia tanah, termasuk aktinomisetes, diketahui mampu menghasilkan berbagai enzim hidrolitik dan antibiotik yang dapat dimanfaatkan sebagai agens pengendalian hayati nematoda. Oleh karena itu,survei dilakukan di beberapa daerah di Yogyakarta, Jawa Tengah, dan Jawa Timur untuk mencari aktinomisetes yang mempunyai aktivitas kitinolitik, proteolitik dan kitino-proteolitik. Isolasi aktinomisetes menghasilkan 84 isolat, dan yang terbanyak diperoleh dari limbah kepala udang (26 isolat. Setelah dilakukan seleksi berdasarkan kemampuannya menghidrolisis kitin dan protein dalam medium, yang mempunyai aktivitas hidrolisis protein, kitin, protein dan kitin tertinggi berturut-turut adalah isolat PSJ 27, TL 8, dan TL 10. Hasil uji enzim kasar yang dihasilkan isolat terpilih terhadap perusakan kulit telur nematoda puru-akar menunjukkan bahwa isolat yang memiliki

  20. Identification of Virulence Factors in Nematode-Trapping Fungi - Insights from Genomics, Transcriptomics and Proteomics

    OpenAIRE

    Andersson, Karl-Magnus

    2013-01-01

    Nematode-trapping fungi are soil-living organisms with the unique ability to capture and infect free-living nematodes. The interest in studying these fungi arises from their potential use as biological control agents for plant- and animal-parasitic nematodes. To enter the parasitic stage, nematode-trapping fungi develop different kinds of trapping structures. In order to understand more about the evolution of parasitism in the nematode-trapping fungi and to identify virulence factors in these...

  1. Cereal Cyst Nematode (Heterodera avenae) on Oats. II. Early Root Development and Nematode Tolerance

    OpenAIRE

    Volkmar, K. M.

    1989-01-01

    The effect of Heterodera avenae infestation on early seminal and lateral root growth was examined in four oat genotypes differing in tolerance to H. avenae. Recently emerged seminal roots were inoculated with a range of H. avenae larval densities, then transferred a hydroponic system to remove the effect of later nematode penetration on root development. Intolerance to H. avenae was assessed in terms of impairment of seminal root extension resulting in fewer primary lateral roots emerging fro...

  2. Plant nematodes in South Africa. 11. Checklist of plant nematodes of the protected areas of KwaZulu-Natal

    Directory of Open Access Journals (Sweden)

    Mariette Marais

    2013-03-01

    Full Text Available Nematodes are some of the most abundant soil organisms and are an essential part of soil ecology. These organisms are used as indicator organisms and can be linked to soil health. Biological collections contain vast amounts of data, with the National Collection of Nematodes housed at the Plant Protection Research Institute, Agricultural Research Council being no different. During the digitising of the collection a number of unpublished records of plant nematodes reported from protected areas in KwaZulu-Natal were found in the South African Plant-Parasitic Nematode Survey database. A total of 222 plant nematode species belonging to 39 genera were reported from the province, with only 94 of these species reported from the protected areas and 172 and 159 species reported from uncultivated (outside the protected areas and cultivated areas, respectively. Only nine species, Criconema silvum, Criconema talanum, Helicotylenchus marethae, Ogma dracomontanum, Ogma louisi, Ogma ueckermanni, Paralongidorus deborae, Trichodorus rinae and Xiphinemella marindae were described from protected areas, whilst O. dracomontanum, P. deborae and T. rinae were subsequently also reported from other provinces. Conservation implications: A higher degree of diversity of nematodes was observed in the unprotected areas of the province. The observation suggests that nematode fauna, and by implication also other invertebrates, are not adequately protected.

  3. Evaluation of Cultivars, Experimental Lines and Plant Introduction Collection of Sainfoin for Resistance to Meloidogyne hapla Chitwood.

    Science.gov (United States)

    Wofford, D S; Gray, F A

    1987-01-01

    Stands of several cultivars and experimental lines of sainfoin (Onobrychis viciifolia) were severely reduced (92% average loss) in a field naturally infested with Meloidogyne hapla. Stands of two alfalfa cultivars included in the test were unaffected. In studies conducted in the greenhouse with plants inoculated at the time of seeding, average mortality was 55% for sainfoin entries and 7% for Ladak alfalfa. Little mortality occurred when plants were inoculated after establishment. Three months after inoculation, all sainfoin entries were heavily galled (range of 3.3-3.7 on a scale of 1-4) while roots of Ladak were only slightly galled (rating of 1.6). Intermating of plants selected in the field plots for resistance to M. hapla showed a slight increase in resistance. Of the 147 plant introduction lines tested in the greenhouse, none were resistant to M. hapla.

  4. Excretory/secretory products of anisakid nematodes

    DEFF Research Database (Denmark)

    Mehrdana, Foojan; Buchmann, Kurt

    2017-01-01

    Parasites from the family Anisakidae are widely distributed in marine fish populations worldwide and mainly nematodes of the three genera Anisakis, Pseudoterranova and Contracaecum have attracted attention due to their pathogenicity in humans. Their life cycles include invertebrates and fish...... as intermediate or transport hosts and mammals or birds as final hosts. Human consumption of raw or underprocessed seafood containing third stage larvae of anisakid parasites may elicit a gastrointestinal disease (anisakidosis) and allergic responses. Excretory and secretory (ES) compounds produced...... by the parasites are assumed to be key players in clinical manifestation of the disease in humans, but the molecules are likely to play a general biological role in invertebrates and lower vertebrates as well. ES products have several functions during infection, e.g. penetration of host tissues and evasion of host...

  5. Efeito da solarização, adubação química e orgânica no controle de nematóides em alface sob cultivo protegido Effect of solarization, chemical and organic fertilization on the control of nematode on greenhouse lettuce

    Directory of Open Access Journals (Sweden)

    Marlene G da Silva

    2006-12-01

    Full Text Available Os efeitos da solarização do solo associados à adubação no controle de nematóides e na produtividade da alface cultivar "Verônica" foram avaliados em solo naturalmente infestado. Dois experimentos foram conduzidos, um com e outro sem solarização, em casa de vegetação, ambos com cinco tratamentos: adubação orgânica; nitrogênio na forma amoniacal (NH4; adubação com NPK; adubação orgânica mais NPK; testemunha (sem adubação. No experimento solarizado, o solo foi coberto durante 132 dias com filme plástico transparente. A população de nematóides foi avaliada em duas camadas (0-10 cm e 10-20 cm, e as coletas de solo foram feitas em três épocas (antes da implantação do experimento; após a solarização; após a colheita. O delineamento experimental foi o de blocos ao acaso com três repetições em parcelas sub-subdivididas, com medidas no espaço e no tempo (5 adubações x 2 camadas x 3 épocas, e a comparação entre experimentos foi feita pela análise conjunta. O efeito da solarização sobre o controle de nematóides dependeu da adubação e camada do solo. A solarização reduziu a população de nematóides na camada de 0-10 cm em todos os tratamentos de adubação. A solarização associada ao NH4 reduziu a diversidade na camada de 10-20 cm. A solarização combinada às adubações orgânica, N-NH4, NPK e orgânica mais NPK reduziu de maneira eficiente o número de galhas, o número de massas de ovos e a população de nematóides fitoparasitas nas raízes, em especial de Meloidogyne spp. Solarização combinada à adubação orgânica apresenta potencial para controle de nematóides e redução do uso de agrotóxicos.The effect of soil solarization and fertilization was evaluated for nematode control in 'Veronica' lettuce in naturally infested soil. The two greenhouse experiments consisted of five fertilization treatments: organic fertilization; ammoniacal nitrogen (ammonium sulphate; NPK fertilization; organic

  6. Variation in estuarine littoral nematode populations over three spatial scales

    Science.gov (United States)

    Hodda, M.

    1990-04-01

    The population characteristics of the nematode fauna from five replicate cores taken over four seasons at nine sites within mangroves, at three different estuaries on the south-east coast of Australia, are compared. Using cluster analysis, principal co-ordinate analysis and other statistical techniques, the variation in nematode populations is identified as arising from several sources: temperature changes between the more northerly and southerly estuaries (5%); changes in grain size and organic content of the sediment between sites (22%); changes between sites in the frequency of samples containing certain types of food, particularly associated with pools of water and surface topography (30%); stochastic changes in nematode populations within individual samples, probably caused by small scale spatial and temporal variability in food sources (35%); and seasonal changes at all the sites and estuaries (8%). The implications of this pattern of variation for the biology of the nematodes is discussed.

  7. Excretory/secretory products from the gastrointestinal nematode Trichuris muris.

    Science.gov (United States)

    Tritten, Lucienne; Tam, Mifong; Vargas, Mireille; Jardim, Armando; Stevenson, Mary M; Keiser, Jennifer; Geary, Timothy G

    2017-07-01

    To better control gastrointestinal nematode infections in humans and animals, it is important to understand the strategies used by these parasites to modulate the host immune system. In this regard, molecules released by parasites have been attributed crucially important roles in host-parasite negotiations. We characterized the excretory/secretory (E/S) microRNA (miRNA) and protein profiles from the mouse gastrointestinal nematode parasite Trichuris muris. Released miRNAs were subjected to miRNA sequencing and E/S proteins were analysed by mass spectrometry. Fourteen miRNAs were identified in T. muris exosome-like vesicles, as well as 73 proteins of nematode origin, 11 of which were unique to this study. Comparison with published nematode protein secretomes revealed high conservation at the functional level. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Transgenesis in parasitic nematodes: building a better array

    Science.gov (United States)

    Lok, James B.

    2011-01-01

    In spite of recent progress in the development of transgenesis in parasitic nematodes, several impediments remain before this methodology can become a practical and widely employed tool in parasitology. Recently published studies on transgenesis in the necromenic nematode Pristionchus pacificus from the laboratory of Ralf Sommer highlight several leads that might be valuable as efforts to refine current systems in obligate parasites go forward. PMID:19617000

  9. Ecostructuring of marine nematode communities by submarine groundwater discharge.

    Science.gov (United States)

    Grzelak, Katarzyna; Tamborski, Joseph; Kotwicki, Lech; Bokuniewicz, Henry

    2018-05-01

    Inputs of submarine groundwater discharge (SGD) to the coastal ocean may alter local and regional-scale biology. Here, we report on nematode assemblages along the north shore of Long Island, NY. We test if nematode communities differed between sites impacted by mixed fresh-saline SGD and where SGD is exclusively saline. Diversity of nematodes was low at sites impacted by fresh SGD and communities were dominated by a few opportunistic genera. Moreover, a set of typical freshwater nematode genera restricted to impacted sites was observed. Their presence in the marine coastal zone is exceptional and underlines the structuring role that fresh SGD plays in the local ecosystem. Saline SGD structured nematode assemblages differently compared to sites impacted by fresh SGD. The number of nematode genera was markedly higher at saline SGD sites, with a different community structure. This study highlights the importance to which inputs of fresh SGD may have on local ecosystem diversity in marine coastal environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Targeted mutagenesis in a human-parasitic nematode.

    Directory of Open Access Journals (Sweden)

    Spencer S Gang

    2017-10-01

    Full Text Available Parasitic nematodes infect over 1 billion people worldwide and cause some of the most common neglected tropical diseases. Despite their prevalence, our understanding of the biology of parasitic nematodes has been limited by the lack of tools for genetic intervention. In particular, it has not yet been possible to generate targeted gene disruptions and mutant phenotypes in any parasitic nematode. Here, we report the development of a method for introducing CRISPR-Cas9-mediated gene disruptions in the human-parasitic threadworm Strongyloides stercoralis. We disrupted the S. stercoralis twitchin gene unc-22, resulting in nematodes with severe motility defects. Ss-unc-22 mutations were resolved by homology-directed repair when a repair template was provided. Omission of a repair template resulted in deletions at the target locus. Ss-unc-22 mutations were heritable; we passed Ss-unc-22 mutants through a host and successfully recovered mutant progeny. Using a similar approach, we also disrupted the unc-22 gene of the rat-parasitic nematode Strongyloides ratti. Our results demonstrate the applicability of CRISPR-Cas9 to parasitic nematodes, and thereby enable future studies of gene function in these medically relevant but previously genetically intractable parasites.

  11. Communities of terrestrial nematodes after different approaches to heathland restoration

    Science.gov (United States)

    Radochova, Petra; Frouz, Jan

    2016-04-01

    Since the 20th century, the distribution of European heathlands rapidly decreased due to agricultural intensification, heavy use of artificial fertilizers or acidification (Aerts & Heil, 1993). Therefore, various attempts of heathland restoration are under way in these days. Analysis of nematode community composition can be one of the tools suitable for succession evaluation (Ferris et al., 2001). In 2011, 2013 and 2014, soil samples were collected from heathland restoration experiment (launched in 2011) where different restoration methods were applied in a 3 × 3 factorial experiment; existing heathlands were also sampled to identify the target community both in dry and wet heathland. A total of 60 samples of extracted nematodes were analysed for absolute abundance, trophic groups, and genera dominance. Various indices were calculated to describe the nematode community. We were able to prove faster development of wet heathlands towards the target community. However, because of large data variability, there was no significant difference between treatments. Development of wet and dry heathlands differed also in increased proportion of omniphagous nematodes in 2013 and predators in 2014 in dry heathlands. After three years of heathland restoration, nematode community has not yet reached parameters of the target community. References Aerts, R., Heil, G. W., 1993. Heathlands: patterns and processes in a changing environment, 1st ed, Geobotany: 20. Springer Netherlands, Dordrecht, p. 229. Ferris, H., Bongers, T., De Goede, R. G. M., 2001. A framework for soil food web diagnostics: Extension of the nematode faunal analysis oncept. Appl. Soil Ecol. 18, 13-29.

  12. Seleção para resistência de genótipos de cenoura aos nematóides-das-galhas Selection for carrot genotypes resistance to root-knot nematodes in field and greenhouse

    Directory of Open Access Journals (Sweden)

    Giovani O da Silva

    2011-09-01

    Full Text Available Foi verificada a relação entre caracteres avaliados em campo e casa-de-vegetação, relativos à avaliação de genótipos de cenoura quanto à resistência ao nematóide-das-galhas (Meloidogyne spp., visando identificar quais caracteres possibilitam a diferenciação entre os genótipos e verificar a possibilidade de avaliação apenas em um ambiente ou a eliminação de caracteres que apresentem correlação alta. Avaliaram-se 38 progênies da população '0812518' e 31 progênies da população '0812519', além das cultivares Brasília e Kuronan como testemunhas tolerante e suscetível, respectivamente. Em campo naturalmente infestado por uma mistura de Meloidogyne incognita raça 1 e Meloidoigyne javanica, a seleção para resistência ao nematóide-das-galhas foi realizada com base na menor porcentagem de infecção na raiz principal dos genótipos de cenoura, rendimento de raiz e o fator de reprodução, enquanto que em casa-de-vegetação, para cada uma das mesmas espécies de nematóides e também para a mistura de ambas, foi medido o índice de galhas e índice de massa de ovos. Verificou-se que não houve possibilidade de seleção em apenas um dos ambientes testados ou a eliminação de caracteres, indicando que para a obtenção de cultivares mais produtivas e mais tolerantes é necessária a seleção combinada nos diferentes caracteres e ambientes. Para o experimento realizado em campo foi possível diferenciar os genótipos apenas para o rendimento de raiz. No experimento em casa-de-vegetação, para todos os caracteres foi possível identificar genótipos superiores. Porém, as médias das populações não foram melhores que a testemunha 'Brasília' da qual estas se originaram, confirmando a necessidade da busca por métodos mais eficientes de seleção.We verified the relation among the evaluated characters in field and greenhouse, concerning to the evaluation to root-knot nematode (Meloidogyne spp. for the carrot crop, to

  13. Ação nematicida de extratos de alho, mostarda, pimenta malagueta, de óleo de mostarda e de dois produtos à base de capsainóides e alil isotiocianato sobre juvenis de Meloidogyne javanica, (treub Chitwood, 1949, em casa de vegetação

    Directory of Open Access Journals (Sweden)

    Wânia dos Santos Neves

    2009-12-01

    o extrato clorofórmico de pimenta, o óleo de mostarda, o produto comercial Champon® e um produto em desenvolvimento na UFV, chamado DS, a base de capsaicina, capsainóides e alil isotiocianato em diferentes concentrações. Os produtos Champon® e DS e o óleo de mostarda reduziram o número de ovos e galhas quando comparados à testemunha em todas as concentrações testadas. O extrato de pimenta apresentou o melhor resultado na concentração de 400 ppm, reduzindo o número de ovos e galhas em relação à testemunha, porém esse foi bem maior quando comparado com os demais produtos testados.Neves, W.S; Freitas, L.G.; Coutinho, M.M.; Giaretta-Dallemole, R.; Fabry, C.F.S.; Dhingra, O.D. & Ferraz, S. Nematicidal activity of extracts of red hot chili pepper, mustard and garlic on Meloidogyne javanica in green house. Summa Phytopathologica, v.35, n.4, p.255-261, 2009 The experiment had the objectives of evaluate the nematicidal activity of botanical extracts of chili pepper fruits (Capsicum frutescens, mustard (Brassica campestris and garlig (Allium sativum on the root-knot nematode, Meloidogyne javanica in tomato plants in the greenhouse, and in a second step, to compare the best extracts for the reduction of the number of eggs and root galls with two products containing capsaicin, capsainoids and allyl isothiocyanate. A sieved mixture of soil and sand 1:1 (v:v was used to fill plastic pots and infested with 4000 eggs of M. javanica. After 4 days, 20 mL of one of the extracts, in the concentration of 1000ppm, were poured over the soil of each pot. Water was poured in the test treatment. Twenty day-old tomato seedlings were planted, one per pot, four days after the aplication of the extracts. Forty five days after planting, the number of galls and eggs per plant was evaluated. The chloroformic and cetonic extracts of chili pepper and the mustard oil presented the highest effect on the nematode population, differing from the control treatment in respect to the

  14. GABA localization in the nematode Ascaris

    Energy Technology Data Exchange (ETDEWEB)

    Guastella, J.

    1988-01-01

    A histochemical approach was used to examine the distribution of GABA-associated neurons in the nematode Ascaris, an organism whose small number of morphologically simple neurons make it an excellent preparation for analyzing neuronal phenotypes. Two GABAergic markers were examined: GABA-like immunoreactivity (GLIR), a marker for endogenous stores of GABA; and ({sup 3}H)-GABA uptake, a marker for GABA uptake sites. Strong GLIR was present in the cell bodies, neurites and commissures of dorsal and ventral inhibitory motorneurons present in this region. Strong GLIR was also present in the cell bodies and processes of the four RME neurons in the nerve ring and in several other ganglionic neurons. Staining was absent in excitatory motorneurons, in ventral cord interneurons and in muscle cells and hypodermis. GABA uptake sites were found in single neural processes in both the ventral and dorsal nerve cords. ({sup 3}H)-GABA labeling was also observed in the other two RME cells and several other cephalic neurons. Four putative cholinergic excitatory motorneurons in the retrovesicular ganglion (RVG) were heavily labeled. Ventral and dorsal nerve cord inhibitory motorneurons did not take up ({sup 3}H)-GABA. Labeling of the ventral cord excitatory motorneuron somata and cell bodies was at or slightly above background. Heavy labeling of muscle cells was also observed.

  15. Nematode assemblages in the rhizosphere of spring barley (Hordeum vulgare L.) depended on fertilisation and plant growth phase

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård

    2004-01-01

    rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley......rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley...

  16. Management of disease complex caused by root knot nematode and root wilt fungus on pigeonpea through soil organically enriched with Vesicular Arbuscular Mycorrhiza, karanj (Pongamia pinnata) oilseed cake and farmyard manure.

    Science.gov (United States)

    Goswami, B K; Pandey, Rajesh Kumar; Goswami, Jaideep; Tewari, D D

    2007-11-01

    This investigation was undertaken to compare the percentage response of colonization and development of VA-Mycorrhiza (Glomus fasciculatum) on a number of pulse crops viz. cowpea, chickpea, soybean, pigeonpea and lentil under glasshouse conditions. Among the above-mentioned crops, pigeonpea exhibited the best performance and was selected for further studies. In this host the development and colonization percentage of G. fasciculatum was investigated under two separate substrates i. e. soil amended with FYM and karanj oilseed cake keeping a control treatment of field soil. A third treatment amended with karanj oilseed cake and farm yard manure (FYM) was also kept which responded best in terms of colonization percentage. This treatment showing improved plant health as well as integration with G. fasciculatum was selected as an ideal treatment for the management of disease complex caused by root knot nematode, Meloidogyne incognita and root wilt fungus, Fusarium udum on pigeonpea. Thus the treatment constituting FYM, karanj oilseed cake and VA-Mycorrhiza reduced the disease incidence caused by both maladies to a great extent with the most promising improvement in plant growth parameters as compared to all others. The present investigation, in addition to proposing an ideal eco-friendly treatment for the management of this disease complex also proposed an excellent medium for the proliferation of the obligate bio-protectant, G. fasciculatum.

  17. Screening edible ginger and turmeric cultivars for resistance to root-knot nematodes

    Science.gov (United States)

    Twenty-two edible ginger and turmeric cultivars were screened for resistance or tolerance to Meloidogyne incognita. Plants were raised in 66 L grow bags in greenhouses in Hawaii according to established practices for producing bacterial wilt-free ginger. Three months after planting, each grow bag ...

  18. Plant and soil nematodes from Lokchao Yangoupokpi Wildlife Sanctuary, Manipur, India

    Directory of Open Access Journals (Sweden)

    N. Mohilal

    2009-03-01

    Full Text Available In the present study soil samples were collected from Lokchao Yangoupokpi Wildlife Sanctuary to investigate about what nematode species are associated with different plant hosts. This study shows rich nematode diversity in the sanctuary.

  19. Predation rates and prey selectivity in two predacious estuarine nematode species

    NARCIS (Netherlands)

    Moens, T.; Herman, P.M.J.; Verbeeck, L.; Steyaert, M.; Vincx, M.

    2000-01-01

    Enoploides longispiculosus and Adoncholaimus fuscus are representatives of nematode genera prominent in sediments of the North Sea and adjacent estuaries. Both are predatory nematodes, although predation is facultative in the latter. The present study investigates functional responses and prey

  20. Nucleic acid transfection and transgenesis in parasitic nematodes.

    Science.gov (United States)

    Lok, James B

    2012-04-01

    Transgenesis is an essential tool for assessing gene function in any organism, and it is especially crucial for parasitic nematodes given the dwindling armamentarium of effective anthelmintics and the consequent need to validate essential molecular targets for new drugs and vaccines. Two of the major routes of gene delivery evaluated to date in parasitic nematodes, bombardment with DNA-coated microparticles and intragonadal microinjection of DNA constructs, draw upon experience with the free-living nematode Caenorhabditis elegans. Bombardment has been used to transiently transfect Ascaris suum, Brugia malayi and Litomosoides sigmodontis with both RNA and DNA. Microinjection has been used to achieve heritable transgenesis in Strongyloides stercoralis, S. ratti and Parastrongyloides trichosuri and for additional transient expression studies in B. malayi. A third route of gene delivery revisits a classic method involving DNA transfer facilitated by calcium-mediated permeabilization of recipient cells in developing B. malayi larvae and results in transgene inheritance through host and vector passage. Assembly of microinjected transgenes into multi-copy episomal arrays likely results in their transcriptional silencing in some parasitic nematodes. Methods such as transposon-mediated transgenesis that favour low-copy number chromosomal integration may remedy this impediment to establishing stable transgenic lines. In the future, stable transgenesis in parasitic nematodes could enable loss-of-function approaches by insertional mutagenesis, in situ expression of inhibitory double-stranded RNA or boosting RNAi susceptibility through heterologous expression of dsRNA processing and transport proteins.

  1. The FMRFamide-like peptide family in nematodes

    Directory of Open Access Journals (Sweden)

    Katleen ePeymen

    2014-06-01

    Full Text Available In the three decades since the FMRFamide peptide was isolated from the mollusk Macrocallista nimbosa, structurally similar peptides sharing a C-terminal RFamide motif have been identified across the animal kingdom. FMRFamide-like peptides (FLPs represent the largest known family of neuropeptides in invertebrates. In the phylum Nematoda, at least 32 flp genes are classified, making the FLP system of nematodes unusually complex. The diversity of the nematode FLP complement is most extensively mapped in Caenorhabditis elegans, where over 70 FLPs have been predicted. FLPs have shown to be expressed in the majority of the 302 C. elegans neurons including interneurons, sensory and motor neurons. The vast expression of FLPs is reflected in the broad functional repertoire of nematode FLP signaling, including neuroendocrine and neuromodulatory effects on locomotory activity, reproduction, feeding, and behavior. In contrast to the many identified nematode FLPs, only few peptides have been assigned a receptor and there is the need to clarify the pathway components and working mechanisms of the FLP signaling network. Here, we review the diversity, distribution, and functions of FLPs in nematodes.

  2. Smart Parasitic Nematodes Use Multifaceted Strategies to Parasitize Plants

    Directory of Open Access Journals (Sweden)

    Muhammad A. Ali

    2017-10-01

    Full Text Available Nematodes are omnipresent in nature including many species which are parasitic to plants and cause enormous economic losses in various crops. During the process of parasitism, sedentary phytonematodes use their stylet to secrete effector proteins into the plant cells to induce the development of specialized feeding structures. These effectors are used by the nematodes to develop compatible interactions with plants, partly by mimicking the expression of host genes. Intensive research is going on to investigate the molecular function of these effector proteins in the plants. In this review, we have summarized which physiological and molecular changes occur when endoparasitic nematodes invade the plant roots and how they develop a successful interaction with plants using the effector proteins. We have also mentioned the host genes which are induced by the nematodes for a compatible interaction. Additionally, we discuss how nematodes modulate the reactive oxygen species (ROS and RNA silencing pathways in addition to post-translational modifications in their own favor for successful parasitism in plants.

  3. Soy desiccants herbicides acting in nematode populations on community land

    Directory of Open Access Journals (Sweden)

    Lucas Baiochi Riboldi

    2013-12-01

    Full Text Available The use of herbicides is the main method of weed control in soybeans. Desiccants are also being used routinely to anticipate the harvest and / or minimize the deterioration of seed quality. There is the possibility of direct or indirect contact with such pesticides, affect the community of nematodes in the soil. However, such effects and their magnitudes are yet to be clarified, especially in the case of selective herbicides. Thus, the objective of this study was to evaluate the use of selective herbicides in soybean on nematodes harmful to the crop. The experiment was conducted with transgenic soybean (‘M-SOY 7908RR’. The experimental design was a randomized block design with the following treatments: paraquat (400 g a.i ha-1, diquat (200 g a.i ha-1, a mixture of paraquat and diquat (300 + 150 g a.i ha-1, two doses of carfentrazone ethyl (20 g a.i ha-1 and 30 g a.i ha-1 and control (without desiccant application. The nematode community in the area was monitored in four periods. In none of those was found significant variation in the populations of nematodes harmful to soybeans, due to the application of any of desiccants. However, especially in the last sampling time, the desiccant application always resulted in increased populations of free-living nematodes and parasites those considered weak for soybean.

  4. Signatures of adaptation to plant parasitism in nematode genomes.

    Science.gov (United States)

    Bird, David McK; Jones, John T; Opperman, Charles H; Kikuchi, Taisei; Danchin, Etienne G J

    2015-02-01

    Plant-parasitic nematodes cause considerable damage to global agriculture. The ability to parasitize plants is a derived character that appears to have independently emerged several times in the phylum Nematoda. Morphological convergence to feeding style has been observed, but whether this is emergent from molecular convergence is less obvious. To address this, we assess whether genomic signatures can be associated with plant parasitism by nematodes. In this review, we report genomic features and characteristics that appear to be common in plant-parasitic nematodes while absent or rare in animal parasites, predators or free-living species. Candidate horizontal acquisitions of parasitism genes have systematically been found in all plant-parasitic species investigated at the sequence level. Presence of peptides that mimic plant hormones also appears to be a trait of plant-parasitic species. Annotations of the few genomes of plant-parasitic nematodes available to date have revealed a set of apparently species-specific genes on every occasion. Effector genes, important for parasitism are frequently found among those species-specific genes, indicating poor overlap. Overall, nematodes appear to have developed convergent genomic solutions to adapt to plant parasitism.

  5. EFECTO NEMATICIDA DE EXTRACTOS DE Quassia amara Y Brugmansia suaveolens SOBRE Meloidogyne sp. ASOCIADO AL TOMATE EN NICARAGUA

    Directory of Open Access Journals (Sweden)

    Wilber Salazar-Ant\\u00F3n

    2014-01-01

    Full Text Available El objetivo de este trabajo fue evaluar extractos de hojas de Quassia amara L. (Simaroubaceae y flores de Brugmansia suaveolens L. (Solanaceae para determinar su efecto nematicida contra Meloidogyne sp. El estudio se realizó en el Campus Agropecuario de la Universidad Nacional Autónoma de Nicaragua-León (UNAN- León en el año 2012. El material vegetal fue deshidratado, pulverizado y sus compuestos fueron extraídos utilizando como solvente metanol. Este estudio se realizó in vitro, se evaluó la mortalidad de los juveniles de Meloidogyne sp. en segundo instar después de 12, 24 y 48 horas de exposición a los extractos. Además, estos se aplicaron a plantas de tomate en maceteras bajo condiciones de invernadero, cuantificándose las poblaciones de nematodos a los 25, 50 y 75 días de exposición al extracto (DEE. En el experimento in vitro Q. amara y B. suaveolens diluidos al 10%, presentaron los más altos porcentajes de mortalidad después de 48 h, alcanzando 89 y 78% de juveniles muertos, respectivamente. En maceteras se evaluó la mortalidad de juveniles, índice de agallamiento (IA y factor de reproducción (FR. Los mejores resultados para Q. amara se obtuvieron a los 25 DEE, con un porcentaje de mortalidad de 80%, un IA de 1 en una escala de 0-5 y FR de 0,20. Con B. suaveolens, a los 25 DEE se alcanzó el mayor porcentaje de mortalidad de 71%, un IA de 1,2 y un FR de 0,29. Estos resultados in vitro y en maceteras evidenciaron que ambos extractos poseen propiedades nematicidas, ya que redujeron significativamente (P≤0,05 las poblaciones de nematodos, su reproducción y el nivel de agallamiento de las raíces de tomate.

  6. Respiratory nematodes in cat populations of Italy.

    Science.gov (United States)

    Di Cesare, Angela; Veronesi, Fabrizia; Grillotti, Eleonora; Manzocchi, Simone; Perrucci, Stefania; Beraldo, Paola; Cazzin, Stefania; De Liberato, Claudio; Barros, Luciano A; Simonato, Giulia; Traversa, Donato

    2015-12-01

    The occurrence of common respiratory parasites of domestic cats (the metastrongyloid "cat lungworm" Aelurostrongylus abstrusus and the trichuroid Capillaria aerophila) and of neglected respiratory nematodes of felids (Troglostrongylus brevior, Angiostrongylus chabaudi and Oslerus rostratus) was here evaluated in two and three geographical sites of Northern and Central Italy, respectively. In 2014-2015, individual fecal samples of 868 domestic cats were examined microscopically and genetically, and epidemiological data related to parasitic infections were evaluated as possible risk factors by binary logistic regression models. The most common parasite was A. abstrusus in both mono- and poli-specific infections, followed by T. brevior and C. aerophila, while cats scored negative for other parasites. Cats positive for A. abstrusus (1.9-17 % infection rate) and C. aerophila (0.9-4.8 % infection rate) were found in all examined sites, while cats scored positive for T. brevior (1-14.3 % infection rate) in four sites. Also, T. brevior was here found for the first time in a domestic cat from a mountainous area of Northern Italy. The occurrence of lungworms was statistically related to the presence of respiratory signs and more significant in cats with mixed infection by other lungworms and/or intestinal parasites. Cats living in site C of Central Italy resulted statistically more at risk of infection for lungworms than cats living in the other study sites, while animals ageing less than 1 year were at more risk for troglostrongylosis. Finally, the presence of lungworms was more significant in cats with mixed infection by other lungworms and/or intestinal parasites. These results are discussed under epidemiological and clinical points of views.

  7. A Treadmill to Localize, Exercise, and Measure the Propulsive Power of Nematodes

    Science.gov (United States)

    Yuan, Jinzhou; Chuan, Han-Sheng; Gnatt, Michael; Raizen, David; Bau, Haim

    2011-11-01

    The nematodes C. elegans is often used as model biological system to study the genetic basis of behavior, disease-progression, and aging, as well as to develop new therapies and screen drugs. On occasion, it is desirable to quantify the nematode's muscle power. Here, we present a kind of nematode treadmill. The device consists of a tapered conduit filled with aqueous solution. The conduit is subjected to a DC electric field and to pressure-driven flow directed from the narrow end. The nematode is inserted at the conduit's wide end. Directed by the electric field (through electrotaxis), the nematode swims deliberately upstream toward the negative pole. As the conduit narrows, the average fluid velocity and the drag force on the nematode increase. Eventually, the nematode arrives at an equilibrium position, at which its propulsive power balances the viscous drag force. The nematode's propulsive power is estimated with direct numerical simulations of the flow field around the nematode. The calculations utilize the experimentally imaged gait as a boundary condition. The device is useful to retain the nematode at a nearly fixed position for prolonged observations under a microscope, to keep the nematode exercising, and to estimate the nematode's power based on the conduit's width at the equilibrium position.

  8. A SNARE-like protein and biotin are implicated in soybean cyst nematode virulence

    Science.gov (United States)

    Some phytoparasitic nematodes have the ability to infect and reproduce on plants that are normally considered resistant to nematode infection. Such nematodes are referred to as virulent and the mechanisms they use to evade or suppress host plant defenses are not well understood. Here, we report the ...

  9. Mechanisms Involved in Nematode Control by Endophytic Fungi.

    Science.gov (United States)

    Schouten, Alexander

    2016-08-04

    Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward nematodes. Evidently, such endophytes can be important in developing more sustainable agricultural practices. The mechanisms playing a role in this quantitative antagonism are poorly understood but most likely multifactorial. This knowledge gap obstructs the progress regarding the development of endophytes or endophyte-derived constituents into biocontrol agents. In part, this may be caused by the fact that endophytic fungi form a rather heterogeneous group. By combining the knowledge of the currently characterized antagonistic endophytic fungi and their effects on nematode behavior and biology with the knowledge of microbial competition and induced plant defenses, the various mechanisms by which this nematode antagonism operates or may operate are discussed. Now that new technologies are becoming available and more accessible, the currently unresolved mechanisms can be studied in greater detail than ever before.

  10. Nematodes of elasmobranch fishes from the southern coast of Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo Knoff

    2001-01-01

    Full Text Available New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S. pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.

  11. Nematodes of elasmobranch fishes from the southern coast of Brazil.

    Science.gov (United States)

    Knoff, M; de São Clemente, S C; Pinto, R M; Gomes, D C

    2001-01-01

    New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S.) pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasitizing an elasmobranch host. Nematode larvae of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are listed from the stomach and spiral valves of several hosts. Anisakidae larvae previously referred in Brazil in the genus Phocanema should be reallocated in Pseudoterranova. Nematodes of the genera Anisakis, Contracaecum, Pseudoterranova and Raphidascaris are reported for the first time parasitizing elasmobranchs in Brazil.

  12. Small-molecule pheromones and hormones controlling nematode development.

    Science.gov (United States)

    Butcher, Rebecca A

    2017-05-17

    The existence of small-molecule signals that influence development in Caenorhabditis elegans has been known for several decades, but only in recent years have the chemical structures of several of these signals been established. The identification of these signals has enabled connections to be made between these small molecules and fundamental signaling pathways in C. elegans that influence not only development but also metabolism, fertility, and lifespan. Spurred by these important discoveries and aided by recent advances in comparative metabolomics and NMR spectroscopy, the field of nematode chemistry has the potential to expand dramatically in the coming years. This Perspective will focus on small-molecule pheromones and hormones that influence developmental events in the nematode life cycle (ascarosides, dafachronic acids, and nemamides), will cover more recent work regarding the biosynthesis of these signals, and will explore how the discovery of these signals is transforming our understanding of nematode development and physiology.

  13. Statistical and Economic Techniques for Site-specific Nematode Management.

    Science.gov (United States)

    Liu, Zheng; Griffin, Terry; Kirkpatrick, Terrence L

    2014-03-01

    Recent advances in precision agriculture technologies and spatial statistics allow realistic, site-specific estimation of nematode damage to field crops and provide a platform for the site-specific delivery of nematicides within individual fields. This paper reviews the spatial statistical techniques that model correlations among neighboring observations and develop a spatial economic analysis to determine the potential of site-specific nematicide application. The spatial econometric methodology applied in the context of site-specific crop yield response contributes to closing the gap between data analysis and realistic site-specific nematicide recommendations and helps to provide a practical method of site-specifically controlling nematodes.

  14. Statistical and Economic Techniques for Site-specific Nematode Management

    Science.gov (United States)

    Liu, Zheng; Griffin, Terry; Kirkpatrick, Terrence L.

    2014-01-01

    Recent advances in precision agriculture technologies and spatial statistics allow realistic, site-specific estimation of nematode damage to field crops and provide a platform for the site-specific delivery of nematicides within individual fields. This paper reviews the spatial statistical techniques that model correlations among neighboring observations and develop a spatial economic analysis to determine the potential of site-specific nematicide application. The spatial econometric methodology applied in the context of site-specific crop yield response contributes to closing the gap between data analysis and realistic site-specific nematicide recommendations and helps to provide a practical method of site-specifically controlling nematodes. PMID:24643451

  15. Improved structural annotation of protein-coding genes in the Meloidogyne hapla genome using RNA-Seq

    Science.gov (United States)

    Guo, Yuelong; Bird, David McK; Nielsen, Dahlia M

    2014-01-01

    As high-throughput cDNA sequencing (RNA-Seq) is increasingly applied to hypothesis-driven biological studies, the prediction of protein coding genes based on these data are usurping strictly in silico approaches. Compared with computationally derived gene predictions, structural annotation is more accurate when based on biological evidence, particularly RNA-Seq data. Here, we refine the current genome annotation for the Meloidogyne hapla genome utilizing RNA-Seq data. Published structural annotation defines 14 420 protein-coding genes in the M. hapla genome. Of these, 25% (3751) were found to exhibit some incongruence with RNA-Seq data. Manual annotation enabled these discrepancies to be resolved. Our analysis revealed 544 new gene models that were missing from the prior annotation. Additionally, 1457 transcribed regions were newly identified on the ends of as-yet-unjoined contigs. We also searched for trans-spliced leaders, and based on RNA-Seq data, identified genes that appear to be trans-spliced. Four 22-bp trans-spliced leaders were identified using our pipeline, including the known trans-spliced leader, which is the M. hapla ortholog of SL1. In silico predictions of trans-splicing were validated by comparison with earlier results derived from an independent cDNA library constructed to capture trans-spliced transcripts. The new annotation, which we term HapPep5, is publically available at www.hapla.org. PMID:25254153

  16. Reação de clones de umezeiro (Prunus mume sieb. et zucc. e cultivares de pessegueiro a Meloidogyne javanica (treub, 1885 Chitwood, 1949

    Directory of Open Access Journals (Sweden)

    Mayer Newton Alex

    2003-01-01

    Full Text Available Um amplo projeto de estudos sobre a utilização do umezeiro como porta-enxerto para pessegueiro está sendo desenvolvido na FCAV/UNESP, Câmpus de Jaboticabal-SP, devido, especialmente, às promissoras características para uso como redutor de vigor da copa e sua boa qualidade de frutos. Alguns trabalhos na literatura citam o umezeiro como resistente ao nematóide das galhas, entretanto dispõe-se de poucas informações. Neste trabalho, teve-se por objetivo estudar a reação de clones de umezeiro e cultivares de pessegueiro a Meloidogyne javanica. O experimento foi conduzido em casa de vegetação, com 6 tratamentos (Clones 05; 10 e 15 de umezeiro e as cultivares Okinawa, Aurora-1 e Dourado-1 de pessegueiro e 9 repetições. As plantas foram mantidas em vasos de cerâmica contendo uma mistura de solo e areia (1:1, v/v, previamente autoclavada a 121ºC e 1kgf.cm-2 por 2 horas. Aos sessenta dias após o plantio, cada planta foi inoculada com 3.000 ovos e juvenis de segundo estádio de Meloidogyne javanica. Aos 100 dias após a inoculação, as plantas foram colhidas para avaliação da massa de matéria fresca do sistema radicular, número de galhas por sistema radicular, número de ovos e juvenis por 10 g de raízes, número de ovos e juvenis por sistema radicular e fator de reprodução. Verificou-se que todos os clones e cultivares de umezeiro e pessegueiro, respectivamente, mostraram-se resistentes a Meloidogyne javanica.

  17. Caracterização genética e molecular de acessos de bananeira a Radopholus similis e Meloidogyne incognita

    OpenAIRE

    Santos, Jansen Rodrigo Pereira

    2011-01-01

    A cultura da bananeira tem grande importância econômica e social em todo o mundo. O Brasil é o quarto produtor mundial de banana, sendo esta cultivada de Norte a Sul do País e, praticamente toda produção é comercializada no mercado interno. Problemas fitossanitários de variadas etiologias reduzem a vida útil dos plantios e levam a perdas na produção e na qualidade dos frutos. Dentre os fitonematoides, Radopholus similis, Meloidogyne incognita, M. javanica, M. arenaria, Helicotylenchus multici...

  18. Stem nematode counteracts plant resistance of aphids in alfalfa, Medicago sativa.

    Science.gov (United States)

    Ramirez, Ricardo A; Spears, Lori R

    2014-10-01

    Plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. Generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. As plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. This study examined the effect of nematode-resistant varieties on aphid (Acyrthosiphon pisum) suppression, and then determined how infection by the stem nematode, Ditylenchus dipsaci, mediated ecological effects on aphids and on plant defense proteins. Four alfalfa (Medicago sativa) varieties were selected with resistance to nematodes only (+,-), aphids only (-,+), nematodes and aphids (+,+), and susceptibility to nematodes and aphids (-,-). Field and greenhouse experiments were conducted to isolate the effect of nematode infection and aphid abundance on each variety. We found that varieties resistant to nematode, regardless of aphid resistance, had the lowest aphid counts, suggesting possible cross-resistance. Aphid abundance, however, increased when plants were exposed to nematodes. Resistant varieties were associated with elevated saponins but these compounds were not affected by insect or pathogen feeding. Concentrations of peroxidases and trypsin inhibitors, however, were increased in nematode resistant varieties when exposed to nematodes and aphids, respectively. The patterns of plant defense were variable, and a combination of resistance traits and changes in nutrient availability may drive positive interactions between nematodes and aphids aboveground.

  19. The Ditylenchus destructor genome provides new insights into the evolution of plant parasitic nematodes.

    Science.gov (United States)

    Zheng, Jinshui; Peng, Donghai; Chen, Ling; Liu, Hualin; Chen, Feng; Xu, Mengci; Ju, Shouyong; Ruan, Lifang; Sun, Ming

    2016-07-27

    Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode, Ditylenchus destructor We performed comparative genomics among the free-living nematode, Caenorhabditis elegans and all the plant nematodes with genome sequences available. We found that, compared with C. elegans, the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also found D. destructor contained more homologies of the key genes in the above processes than the other plant nematodes. We suggest that Ditylenchus spp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts that D. destructor can feed on fungi and has a relatively short life cycle, and that it has similar features to both C. elegans and sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants. © 2016 The Author(s).

  20. High-throughput sequencing of nematode communities from total soil DNA extractions

    DEFF Research Database (Denmark)

    Sapkota, Rumakanta; Nicolaisen, Mogens

    2015-01-01

    nematodes without the need for enrichment was developed. Using this strategy on DNA templates from a set of 22 agricultural soils, we obtained 64.4% sequences of nematode origin in total, whereas the remaining sequences were almost entirely from other metazoans. The nematode sequences were derived from...... in previous sequence-based studies are not nematode specific but also amplify other groups of organisms such as fungi and plantae, and thus require a nematode enrichment step that may introduce biases. Results: In this study an amplification strategy which selectively amplifies a fragment of the SSU from...... a broad taxonomic range and most sequences were from nematode taxa that have previously been found to be abundant in soil such as Tylenchida, Rhabditida, Dorylaimida, Triplonchida and Araeolaimida. Conclusions: Our amplification and sequencing strategy for assessing nematode diversity was able to collect...

  1. Parasitic nematodes in the chimpanzee population on Rubondo Island, Tanzania

    Czech Academy of Sciences Publication Activity Database

    Petrželková, Klára Judita; Hasegawa, H.; Moscovice, L. R.; Kaur, T.; Issa, M. H.; Huffman, M. A.

    2006-01-01

    Roč. 27, č. 3 (2006), s. 767-777 ISSN 0164-0291 Institutional research plan: CEZ:AV0Z60930519 Keywords : chimpanzee * introduced population * nematode * new parasite record * Rubondo Island Subject RIV: EG - Zoology Impact factor: 1.331, year: 2006

  2. Systemic induced tolerance against root-knot nematodes in rice

    African Journals Online (AJOL)

    user

    c Institute of Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology, P.O.. Box 62000, City ... of information from fundamental research in order to get more insight on the interaction between these nematodes ..... 1200TM Automated PCR Set up robot (Corbett Life Science, 2009). All PCR samples ...

  3. Genetic diversity of the potato cyst nematode in the Netherlands

    NARCIS (Netherlands)

    Folkertsma, R.T.

    1997-01-01


    The potato cyst nematodes Globodera rostochiensis (Woll.) Skarbilovich and G. pallida (Stone) originate from the Andes region in South America and have been introduced into Western Europe since 1850. Both species are

  4. Occurence of Anisakids nematodes on Frozen Hake ( Merluccius ...

    African Journals Online (AJOL)

    Samples of the frozen hake were obtained once a week as corresponding to supply in Yenagoa Market Bayelsa State ,Nigeria . From every supply of 10 cartons, 10 pieces of hake were examined for the presence of Anisakids nematodes .The incidence was concluded after sampling continuously every week for 8weeks ...

  5. Top 10 plant-parasitic nematodes in molecular plant pathology

    NARCIS (Netherlands)

    Jones, J.T.; Haegeman, A.; Danchin, E.G.J.; Gaur, H.S.; Helder, J.; Jones, M.G.K.; Kikuchi, T.; Manzanilla-López, R.; Palomares-Rius, J.E.; Wesemael, W.M.L.; Perry, R.N.

    2013-01-01

    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

  6. Prevalence and risk factors for intestinal nematode infections in ...

    African Journals Online (AJOL)

    A community-based cross-sectional study was conducted between November 2010 and February 2011 to assess the prevalence of intestinal nematode infections among children aged 1 – 14 years living in two communities of rural Ebonyi State, Nigeria, characterize the risk factors for infection and develop environmental ...

  7. Prevalence and diversity of gastrointestinal nematodes of cattles in ...

    African Journals Online (AJOL)

    A total of 384 faecal samples for the coproscopic examination were collected and processed using direct faecal floatation method in parasitology laboratory of Jimma University, School of Veterinary medicine. Out of the total sampled cattle, 190 (49.5%) had a gastrointestinal nematode infection. Coprological investigation ...

  8. Faecal nematode egg counts in Merino sheep following natural ...

    African Journals Online (AJOL)

    Unknown

    This study reports line differences in faecal nematode egg counts in strains of Merino sheep after natural challenge, and genetic (co)variances of egg counts with other traits of economic importance. Material and Methods. Sheep from a Merino selection experiment on the Tygerhoek experimental farm in the Southern Cape.

  9. Mechanisms Involved in Nematode Control by Endophytic Fungi

    NARCIS (Netherlands)

    Schouten, Sander

    2016-01-01

    Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward nematodes. Evidently, such endophytes can be important in developing more sustainable agricultural practices. The mechanisms playing a role in this quantitative antagonism are poorly understood

  10. Nematode Parasitemia in School aged Children in Sapele, Delta ...

    African Journals Online (AJOL)

    Two hundred (200) faecal samples were collected from school aged children in four randomly selected primary schools in Sapele metropolis of Delta State, Nigeria, to determine gastrointestinal nematode parasitemia. The formal-ether concentration technique was used to analyse the specimens and data obtained revealed ...

  11. Risk factors associated with gastrointestinal nematode infections of ...

    African Journals Online (AJOL)

    A study was carried out in Nakuru and Mukurweini districts of Kenya to identify the risk factors associated with gastrointestinal nematode (GIN) infection in cattle on 128 dairy farms between June 16th 2010 and August 30th 2010. Faecal samples were collected from the rectum of 419 heads of cattle that were above three ...

  12. The prevalence of gastrointestinal nematode infection and their ...

    African Journals Online (AJOL)

    A cross-sectional study was conducted in Nakuru and Mukurweini districts of Kenya to estimate the prevalence of gastrointestinal nematodes (GIN) and the financial impact of such infections among smallholder dairy farms. Parasitological examination involving feacal egg count and larval culture was employed to determine ...

  13. Gastrointestinal Nematodes and Body Condition Scores of Goats ...

    African Journals Online (AJOL)

    Gastrointestinal (GI) nematodes of 210 trade goats slaughtered in Nsukka area of Enugu state and their effects on body conditions was studied between May and August, 2011. The body condition of each goat were determined and scored on a scale of 1 – 5. Faecal samples were then collected from the goats before ...

  14. Efficacy of two anthelmintics against gastrointestinal nematodes in ...

    African Journals Online (AJOL)

    A study was conducted to determine the efficacy of albendazole (ABZ) and ivermectin (IVM) against gastrointestinal nematodes (GIN) in naturally infected goats in the pastoral region of Karamoja, Uganda. Fifty four (54) small East African goats (female = 36, male = 18), of 4-6 months and from 18 flocks, were allocated to ...

  15. Seasonal patterns of gastrointestinal nematode infections in sheep ...

    African Journals Online (AJOL)

    The seasonal patterns of trichostrongylid nematode infections in Dorper yearlings in a semi-arid area of Kajiado District, Kenya were investigated by analysis faecal egg output, herbage infectivity and post-mortem worm recovery. Rectal faecal samples from 60 animals as well as herbage samples from their grazing fields ...

  16. Field study on nematode resistance in Nelore-breed cattle

    NARCIS (Netherlands)

    Bricarello, P A; Zaros, L G; Coutinho, L L; Rocha, R A; Kooyman, F N J; De Vries, E; Gonçalves, J R S; Lima, L G; Pires, A V; Amarante, A F T

    2007-01-01

    The present study evaluated Nelore cattle with different degrees of resistance to natural infections by gastrointestinal nematodes. One hundred weaned male cattle, 11-12 months of age, were kept on the same pasture and evaluated from October 2003 to February 2004. Faecal and blood samples were

  17. A survey of gastrointestinal nematodes in soil samples in Ibadan ...

    African Journals Online (AJOL)

    This was to determine the comparative level of soil contamination by these helminthes. Out of the 60 top and deep soil samples collected from high-density areas, 12(20%) were positive for various pathogenic gastrointestinal nematodes. They include Ascaris sp., Toxocara canis, Trichuris trichiura, Strongyloides stercoralis, ...

  18. 5 Spatial Distribution of Nematodes at Organic.cdr

    African Journals Online (AJOL)

    user

    live in the thin films of water surrounding soil particles because water aids their mobility (Freckman ... Geostatistics can be used to analyse and quantify spatial autocorrelation by distance and direction (Evans et al., 1999). Geostatistical analysis in previous studies has shown that field-scale autocorrelation in nematode ...

  19. Nematodes and Weeds Control Effects of Pueraria phaseoloides ...

    African Journals Online (AJOL)

    The yield of plantain (Musa spp., AAB Simmonds) declines sharply after 1–2 years of cropping in West and Central Africa, due mainly to weeds and nematodes. A trial was carried out from January 2002 to October 2005 under two land-use systems (LUS) comprising 4–5 year-old bush fallow, dominated by Chromolaena ...

  20. RNA interference in plant parasitic nematodes | Karakas | African ...

    African Journals Online (AJOL)

    Conserved in most eukaryotic organisms, the RNAi pathway is thought to have evolved as a form of innate immunity against viruses and also plays a major role in regulating development and genome maintenance. RNAi has recently been demonstrated in plant parasitic nematodes. It is a potentially powerful investigative ...

  1. testinal nematodes of sheep owned by smallholder farmers in ...

    African Journals Online (AJOL)

    analyzed using the formula described by Dash et al. (1988), arithmetic means, and Presidente (1985), geometric means, of FECR. Nematodes egg counts were subject to logarithmic transformation, [log (x+1)], to stabilize variances (Mar- tin, 1982) and expressed as geometric means for the groups; and also for analy-.

  2. Effect of tanniniferous browse meal on nematode faecal egg counts ...

    African Journals Online (AJOL)

    The effect of tanniniferous browse meal on faecal egg counts (FEC) and intestinal worm burdens was investigated in sheep and goats infested experimentally with gastrointestinal nematodes. Initially, leaves of different browse tree species were assayed for condensed tannin (CT) content using a colorimetric method to ...

  3. Analysis of nematode infection levels among indoor pigs in Thika ...

    African Journals Online (AJOL)

    The infection levels of various species of nematode infection were studied in 35 indoor pig herds in Thika district, Kenya. Faecal samples were ... To reduce these costs, it is recommended that animals should be treated after faecal examination and laboratory determination of the EPG levels.. Kenya Veterinarian Vol.

  4. Foraging behavior and virulence of some entomopathogenic nematodes

    Directory of Open Access Journals (Sweden)

    Manana A. Lortkipanidze

    2016-06-01

    Full Text Available At present the biological control as a pest control technology is becoming more desirable. Biological formulations on basis of entomopathogenic nematodes are one of the effective means for the protection of agricultural and forest plants from harmful insects. Nowadays, the use of entomopathogenic nematodes as biological control agents is a key component in IPM system. The foraging strategies of entomopathogenic nematodes (EPNs vary between species. This variation is consistent with use of different foraging strategies between ambush, cruise and intermediate to find their host insects. In order to ambush prey, some species of EPNs nictate, or raise their bodies of the soil surface so they are better poised to attach passing insects, other species adopt a cruising strategy and rarely nictate. Some species adopt an intermediate strategy between ambush and cruise. We compared in laboratory the foraging strategies of the entomopathogenic nematode species: Steinernema carpocapsae, Heterorhabditis bacteriophora and the recently described species Steinernema tbilisiensis and assessed their virulence against mealworm beetle, Tenebrio molitor L. (Coleoptera: Tenebrionidae. The tests showed that S. tbilisiensis adopts both foraging strategies.

  5. The dynamics of nematode infections of farmed ruminants

    NARCIS (Netherlands)

    Roberts, M.G.; Heesterbeek, J.A.P.

    1995-01-01

    In this paper the dynamics and control of nematode parasites of farmed ruminants are discussed via a qualitative analysis of a differential equation model. To achieve this a quantity, 'the basic reproduction quotient' (Q0), whose definition coincides with previous definitions of R0 for

  6. A critique of current methods in nematode taxonomy | Abebe ...

    African Journals Online (AJOL)

    In the past few decades, there have been efforts to integrate molecular methods and digital 3D image-capturing technology in nematode taxonomy, the former to enhance the accuracy of identification of such a taxonomically challenging group and the latter to communicate morphological data. While the employment of ...

  7. Gastrointestinal nematodes of donkeys in and around Alage, South ...

    African Journals Online (AJOL)

    of lugol's iodine was added to the sediment to differentiate the larvae which stains the free living nematode yellow, while parasitic 3rd stage larvae remain unstained. The larvae was then identified under low power microscopy (10x objective), based on the shape and number of gut cells, relative size of sheath tail and shape ...

  8. Grafted eggplant yield, quality and growth in infested soil with Verticillium dahliae and Meloidogyne incognita Produção, qualidade e crescimento de beringela enxertada, em solo infestado com Verticillium dahliae e Meloidogyne incognita

    Directory of Open Access Journals (Sweden)

    Sebahattin Çürük

    2009-12-01

    Full Text Available The objective of this work was to evaluate the effect of grafting (onto Solanum torvum Sw. on plant growth, yield and fruit quality of the Pala and Faselis eggplant (Solanum melongena L. cultivars, grown in a soil infested with Verticillium dahliae Kleb. and Meloidogyne incognita, or in noninfested soil. Soil infestation decreased yield, plant height, final above-ground biomass, and also reduced fruit mean weight and shoot dry weight depending on cultivar or grafting. Grafting decreased fruit oxalic acid and the soluble solid contents, and increased mean fruit weight, depending on cultivar and soil infestation. Grafting also reduced the negative effects of the pathogens on disease index, plant height and shoot dry weight. Cultivar Pala was more vigorous than Faselis, and S. torvum was a vigorous rootstock. The combination of a vigorous rootstock with a weak cultivar (Faselis is more profitable than that of a vigorous rootstock and a vigorous cultivar (Pala. Using S. torvum as a rootstock for cultivar Faselis, grown in soil infested with the pathogens, is most likely to be useful in conventional and low-input sustainable horticulture, since grafting increases protection against the pathogens, and reduces the losses in quality and yield.O objetivo deste trabalho foi avaliar o efeito sobre a altura de planta, a produção e a qualidade de frutos do enxerto das cultivares de beringela (Solanum melongena L. Pala e Faselis em Solanum torvum Sw., quando cultivadas em solo infestado com Verticillium dahliae e Meloidogyne incognita ou em solo não infestado. A infestação do solo reduziu a produção, altura da planta, biomassa da parte aérea, massa média dos frutos, massa de matéria seca da parte aérea, conforme a cultivar utilizada e a enxertia. A enxertia reduziu os conteúdos de ácido oxálico e de sólidos solúveis e aumentou a massa média de frutos, conforme a cultivar ou a presença do patógeno no solo. A enxertia também reduziu o efeito

  9. Profiling nematode communities in unmanaged flowerbed and agricultural field soils in Japan by DNA barcode sequencing.

    Directory of Open Access Journals (Sweden)

    Hisashi Morise

    Full Text Available Soil nematodes play crucial roles in the soil food web and are a suitable indicator for assessing soil environments and ecosystems. Previous nematode community analyses based on nematode morphology classification have been shown to be useful for assessing various soil environments. Here we have conducted DNA barcode analysis for soil nematode community analyses in Japanese soils. We isolated nematodes from two different environmental soils of an unmanaged flowerbed and an agricultural field using the improved flotation-sieving method. Small subunit (SSU rDNA fragments were directly amplified from each of 68 (flowerbed samples and 48 (field samples isolated nematodes to determine the nucleotide sequence. Sixteen and thirteen operational taxonomic units (OTUs were obtained by multiple sequence alignment from the flowerbed and agricultural field nematodes, respectively. All 29 SSU rDNA-derived OTUs (rOTUs were further mapped onto a phylogenetic tree with 107 known nematode species. Interestingly, the two nematode communities examined were clearly distinct from each other in terms of trophic groups: Animal predators and plant feeders were markedly abundant in the flowerbed soils, in contrast, bacterial feeders were dominantly observed in the agricultural field soils. The data from the flowerbed nematodes suggests a possible food web among two different trophic nematode groups and plants (weeds in the closed soil environment. Finally, DNA sequences derived from the mitochondrial cytochrome oxidase c subunit 1 (COI gene were determined as a DNA barcode from 43 agricultural field soil nematodes. These nematodes were assigned to 13 rDNA-derived OTUs, but in the COI gene analysis were assigned to 23 COI gene-derived OTUs (cOTUs, indicating that COI gene-based barcoding may provide higher taxonomic resolution than conventional SSU rDNA-barcoding in soil nematode community analysis.

  10. Population development of beet cyst nematodes and their damage potential to sugar beets under different temperature regimes

    OpenAIRE

    Bart Vandenbossche; Björn Niere; Stefan Vidal

    2011-01-01

    _Heterodera schachtii_, the white beet cyst nematode, is considered as one of the most important nematode pests on sugar beet and is present in most sugar-beet growing areas. The yellow beet cyst nematode, _Heterodera betae_, is less prevalent but has also been found damaging beet crops. However, knowledge about the damage potential and population dynamics of the yellow beet cyst nematode is limited. The amount of damage inflicted by nematodes is dependent on different factors. An important f...

  11. Activated entomopathogenic nematode infective juveniles release lethal venom proteins.

    Directory of Open Access Journals (Sweden)

    Dihong Lu

    2017-04-01

    Full Text Available Entomopathogenic nematodes (EPNs are unique parasites due to their symbiosis with entomopathogenic bacteria and their ability to kill insect hosts quickly after infection. It is widely believed that EPNs rely on their bacterial partners for killing hosts. Here we disproved this theory by demonstrating that the in vitro activated infective juveniles (IJs of Steinernema carpocapsae (a well-studied EPN species release venom proteins that are lethal to several insects including Drosophila melanogaster. We confirmed that the in vitro activation is a good approximation of the in vivo process by comparing the transcriptomes of individual in vitro and in vivo activated IJs. We further analyzed the transcriptomes of non-activated and activated IJs and revealed a dramatic shift in gene expression during IJ activation. We also analyzed the venom proteome using mass spectrometry. Among the 472 venom proteins, proteases and protease inhibitors are especially abundant, and toxin-related proteins such as Shk domain-containing proteins and fatty acid- and retinol-binding proteins are also detected, which are potential candidates for suppressing the host immune system. Many of the venom proteins have conserved orthologs in vertebrate-parasitic nematodes and are differentially expressed during IJ activation, suggesting conserved functions in nematode parasitism. In summary, our findings strongly support a new model that S. carpocapsae and likely other Steinernema EPNs have a more active role in contributing to the pathogenicity of the nematode-bacterium complex than simply relying on their symbiotic bacteria. Furthermore, we propose that EPNs are a good model system for investigating vertebrate- and human-parasitic nematodes, especially regarding the function of excretory/secretory products.

  12. Practical application of insect-parasitic nematodes and sterile flies

    International Nuclear Information System (INIS)

    Galle, F.; Loosjes, M.

    1987-01-01

    The company 'de Groene Vlieg' started with commercial control of the onion fly by means of the sterile insect technique. At the moment 10 per cent of the Dutch spring sown onions are treated with this method. The mass-rearing, the estimations of populations and the repeated releases of sterilized flies make it a rather complicated method. It can be applied economically per field, but only in areas with a concentration of onion growing. For export we see no possibilities yet. In principle the sterile insect technique can be applied also to other flies (carrot rust fly, cabbage root fly), but a suitable artificial diet is still lacking. Since some years we also rear the insect parasitic nematodes Heterorhabditis sp. and Neoaplectana bibionis. The later is experimentally used with success against Agrotis segetum caterpillars in lettuce. Research will yield more applications of nematodes against different pests. We use Heterorhabditis sp. in practice against the black vine weevil (Otiorhynchus sulcatus), a serious pest in glass houses, tree nurseries and gardens. Good control is achieved with a dose of one half to one million nematodes per square meter in moist soil and with temperatures above 12 degrees C. The application is similar to that of a chemical insecticide. The pest is killed by symbiontic bacteria, released by the nematodes after penetrating into the body cavity of the larvae. The nematodes are delivered by mail. If cooled they can be kept alive for over four weeks in the package. We export already to Switzerland and plan to export also to Western Germany. At this moment a possible admittance is under investigation in the Netherlands for application of a nuclear polyhedrosis virus against Spodoptera exigua caterpillars

  13. Damage-associated responses of the host contribute to defence against cyst nematodes but not root-knot nematodes

    NARCIS (Netherlands)

    Shah, Syed Jehangir; Anjam, Muhammad Shahzad; Mendy, Badou; Anwer, Muhammad Arslan; Habash, Samer S.; Lozano-Torres, Jose L.; Grundler, Florian M.W.; Siddique, Shahid

    2017-01-01

    When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in

  14. A Large Collection of Novel Nematode-Infecting Microsporidia and Their Diverse Interactions with Caenorhabditis elegans and Other Related Nematodes

    Science.gov (United States)

    Zhang, Gaotian; Sachse, Martin; Prevost, Marie-Christine; Troemel, Emily R.; Félix, Marie-Anne

    2016-01-01

    Microsporidia are fungi-related intracellular pathogens that may infect virtually all animals, but are poorly understood. The nematode Caenorhabditis elegans has recently become a model host for studying microsporidia through the identification of its natural microsporidian pathogen Nematocida parisii. However, it was unclear how widespread and diverse microsporidia infections are in C. elegans or other related nematodes in the wild. Here we describe the isolation and culture of 47 nematodes with microsporidian infections. N. parisii is found to be the most common microsporidia infecting C. elegans in the wild. In addition, we further describe and name six new species in the Nematocida genus. Our sampling and phylogenetic analysis further identify two subclades that are genetically distinct from Nematocida, and we name them Enteropsectra and Pancytospora. Interestingly, unlike Nematocida, these two genera belong to the main clade of microsporidia that includes human pathogens. All of these microsporidia are horizontally transmitted and most specifically infect intestinal cells, except Pancytospora epiphaga that replicates mostly in the epidermis of its Caenorhabditis host. At the subcellular level in the infected host cell, spores of the novel genus Enteropsectra show a characteristic apical distribution and exit via budding off of the plasma membrane, instead of exiting via exocytosis as spores of Nematocida. Host specificity is broad for some microsporidia, narrow for others: indeed, some microsporidia can infect Oscheius tipulae but not its sister species Oscheius sp. 3, and conversely some microsporidia found infecting Oscheius sp. 3 do not infect O. tipulae. We also show that N. ausubeli fails to strongly induce in C. elegans the transcription of genes that are induced by other Nematocida species, suggesting it has evolved mechanisms to prevent induction of this host response. Altogether, these newly isolated species illustrate the diversity and ubiquity of

  15. IDENTIFICACIÓN MORFOLÓGICA, MORFOMÉTRICA Y MOLECULAR DE Meloidogyne incognita EN HIGUERA (Ficus carica L. EN COSTA RICA

    Directory of Open Access Journals (Sweden)

    Walter Peraza-Padilla

    2013-01-01

    Full Text Available El objetivo de este estudio fue identificar la especie de Meloidogyne asociada a dos plantaciones de higuera en Costa Rica. En marzo de 2012, en el distrito de Pacayas, provincia de Cartago, se detectaron agallas en los sistemas radicales de plantas de higuera (Ficus carica L. de dos fincas. De las raíces agalladas se extrajeron hembras, masas de huevos y juveniles (J2 de Meloidogyne sp. Se examinaron los patrones perineales de las hembras y los segundos estadios infectivos se analizaron morfológica y molecularmente mediante PCR-RFLP. Se amplificó la región intergénica (IGS del genoma mitocondrial, delimitada por el gen de la subunidad II de la citocromo oxidasa (COII y el gen ribosomal 16S. La población de nematodos se identificó como M. incognita. El tamaño de los productos de PCR generados con los imprimadores C2F3 y 1108 fue de 1,7 kb. Al tratar los productos de PCR con enzimas de restricción, se generaron cuatro fragmentos de 850, 450, 250 y 150 pb con la enzima AluI y dos fragmentos de 1300 y 400 pb con la enzima HinfI.

  16. RNAi-mediated disruption of neuropeptide genes, nlp-3 and nlp-12, cause multiple behavioral defects in Meloidogyne incognita.

    Science.gov (United States)

    Dash, Manoranjan; Dutta, Tushar K; Phani, Victor; Papolu, Pradeep K; Shivakumara, Tagginahalli N; Rao, Uma

    2017-08-26

    Owing to the current deficiencies in chemical control options and unavailability of novel management strategies, root-knot nematode (M. incognita) infections remain widespread with significant socio-economic impacts. Helminth nervous systems are peptide-rich and appear to be putative drug targets that could be exploited by antihelmintic chemotherapy. Herein, to characterize the novel peptidergic neurotransmitters, in silico mining of M. incognita genomic and transciptomic datasets revealed the presence of 16 neuropeptide-like protein (nlp) genes with structural hallmarks of neuropeptide preproproteins; among which 13 nlps were PCR-amplified and sequenced. Two key nlp genes (Mi-nlp-3 and Mi-nlp-12) were localized to the basal bulb and tail region of nematode body via in situ hybridization assay. Mi-nlp-3 and Mi-nlp-12 were greatly expressed (in qRT-PCR assay) in the pre-parasitic juveniles and adult females, suggesting the association of these genes in host recognition, development and reproduction of M. incognita. In vitro knockdown of Mi-nlp-3 and Mi-nlp-12 via RNAi demonstrated the significant reduction in attraction and penetration of M. incognita in tomato root in Pluronic gel medium. A pronounced perturbation in development and reproduction of NLP-silenced worms was also documented in adzuki beans in CYG growth pouches. The deleterious phenotypes obtained due to NLP knockdown suggests that transgenic plants engineered to express RNA constructs targeting nlp genes may emerge as an environmentally viable option to manage nematode problems in crop plants. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Endosymbiont-based immunity in Drosophila melanogaster against parasitic nematode infection.

    Science.gov (United States)

    Yadav, Shruti; Frazer, Joanna; Banga, Ashima; Pruitt, Katherine; Harsh, Sneh; Jaenike, John; Eleftherianos, Ioannis

    2018-01-01

    Associations between endosymbiotic bacteria and their hosts represent a complex ecosystem within organisms ranging from humans to protozoa. Drosophila species are known to naturally harbor Wolbachia and Spiroplasma endosymbionts, which play a protective role against certain microbial infections. Here, we investigated whether the presence or absence of endosymbionts affects the immune response of Drosophila melanogaster larvae to infection by Steinernema carpocapsae nematodes carrying or lacking their mutualistic Gram-negative bacteria Xenorhabdus nematophila (symbiotic or axenic nematodes, respectively). We find that the presence of Wolbachia alone or together with Spiroplasma promotes the survival of larvae in response to infection with S. carpocapsae symbiotic nematodes, but not against axenic nematodes. We also find that Wolbachia numbers are reduced in Spiroplasma-free larvae infected with axenic compared to symbiotic nematodes, and they are also reduced in Spiroplasma-containing compared to Spiroplasma-free larvae infected with axenic nematodes. We further show that S. carpocapsae axenic nematode infection induces the Toll pathway in the absence of Wolbachia, and that symbiotic nematode infection leads to increased phenoloxidase activity in D. melanogaster larvae devoid of endosymbionts. Finally, infection with either type of nematode alters the metabolic status and the fat body lipid droplet size in D. melanogaster larvae containing only Wolbachia or both endosymbionts. Our results suggest an interaction between Wolbachia endosymbionts with the immune response of D. melanogaster against infection with the entomopathogenic nematodes S. carpocapsae. Results from this study indicate a complex interplay between insect hosts, endosymbiotic microbes and pathogenic organisms.

  18. Fast, automated measurement of nematode swimming (thrashing without morphometry

    Directory of Open Access Journals (Sweden)

    Sattelle David B

    2009-07-01

    Full Text Available Abstract Background The "thrashing assay", in which nematodes are placed in liquid and the frequency of lateral swimming ("thrashing" movements estimated, is a well-established method for measuring motility in the genetic model organism Caenorhabditis elegans as well as in parasitic nematodes. It is used as an index of the effects of drugs, chemicals or mutations on motility and has proved useful in identifying mutants affecting behaviour. However, the method is laborious, subject to experimenter error, and therefore does not permit high-throughput applications. Existing automation methods usually involve analysis of worm shape, but this is computationally demanding and error-prone. Here we present a novel, robust and rapid method of automatically counting the thrashing frequency of worms that avoids morphometry but nonetheless gives a direct measure of thrashing frequency. Our method uses principal components analysis to remove the background, followed by computation of a covariance matrix of the remaining image frames from which the interval between statistically-similar frames is estimated. Results We tested the performance of our covariance method in measuring thrashing rates of worms using mutations that affect motility and found that it accurately substituted for laborious, manual measurements over a wide range of thrashing rates. The algorithm used also enabled us to determine a dose-dependent inhibition of thrashing frequency by the anthelmintic drug, levamisole, illustrating the suitability of the system for assaying the effects of drugs and chemicals on motility. Furthermore, the algorithm successfully measured the actions of levamisole on a parasitic nematode, Haemonchus contortus, which undergoes complex contorted shapes whilst swimming, without alterations in the code or of any parameters, indicating that it is applicable to different nematode species, including parasitic nematodes. Our method is capable of analyzing a 30 s movie in

  19. Nematodes Parasites of Teiid Lizards from the Brazilian Amazon Rainforest.

    Science.gov (United States)

    Macedo, L C; Gardner, S L; Melo, F T V; Giese, E G; Santos, J N

    2017-04-01

    This study presents the helminth composition and parameters of infection by several species of nematodes in teiid lizards, Ameiva ameiva ameiva (Linnaeus, 1758), Cnemidophorus cryptus Cole and Dessauer, 1993, and Kentropyx calcarata Spix, 1825 from the Brazilian Amazonian Rainforest. The population of lizards studied were parasitized by 6 species of Phylum Nemata including: Spinicauda spinicauda (Olfers, 1919), Parapharyngodon alvarengai Freitas, 1957, Physaloptera sp. (adults), Physaloptera sp. (larvae), Piratuba digiticauda Lent and Freitas, 1941, and Anisakidae (larvae). The overall prevalence was 66.17% and the mean intensity of infection was 19.40 ± 25.48. The association between the body-length of lizards and the abundance and richness of parasitic nematodes was statistically significant only in Ameiva a. ameiva. A new host record is reported here with 1 specimen of the family Anasakidae in Ameiva a. ameiva. Both S. spinicauda and Physaloptera sp. represent new records from C. cryptus.

  20. Optimizing the application of entomopathogenic nematodes: experimental set-up.

    Science.gov (United States)

    Brusselman, E; Steurbaut, W; Sonck, B

    2007-01-01

    The complex issue concerning the spray application of Entomopathogenic Nematodes (EPNs) with a hydraulic sprayer is still not solved. This research project focuses on the effect of spray application technique on the viability and deposition of EPNs. In this paper the experimental set-up used for this evaluation is described. A modular spray application system has been developed and is currently used to evaluate the effect of different parts of a sprayer on the viability of the EPNs. Based on the results of experiments using this modular spray application system, recommendations regarding pump type, mixing system, nozzle type and filter size will be formulated. Because of the large number of experiments in this research project, an image analysis system for the determination of the viability of the nematodes is developed. This paper describes two experiments comparing the new developed image processing technique with the standard microscopic counting technique.

  1. IMMUNE REGULATING ES-PRODUCTS IN PARASITIC NEMATODES

    DEFF Research Database (Denmark)

    Bahlool, Qusay Zuhair Mohammad; Buchmann, Kurt; Kania, Per Walter

    work elucidates the effect of ES substances on the fish immune system by measuring immune gene expression in spleen and liver of rainbow trout (Oncorhynchus mykiss) injected intraperitoneally with ES products isolated from A. simplex third stage larvae. The overall gene expression profile of exposed...... fish showed a generalized down-regulation of the immune genes tested, suggesting a role of ES proteins in minimizing the immune reaction of rainbow trout against invading nematodes. We also tested the enzymatic activity of the ES proteins and found that lipase, esterase lipase, valine and cysteine...... arylamidases, naphthol-AS-BI-phosphohydrolase and a-galactosidase activities were present in the ES solution. This type of hydrolytic enzyme activity may play a role in nematode penetration of host tissue. Based on the notion that A. simplex ES-proteins may have an immune-depressive effect, it could also...

  2. Assessment of nematode community structure as a bioindicator in river monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.C.; Chen, P.C. [Department of Plant Pathology, National Chung Hsing University, 250 Kuo Kuan Rd, Taichung 402, Taiwan (China); Tsay, T.T., E-mail: tttsay@nchu.edu.t [Department of Plant Pathology, National Chung Hsing University, 250 Kuo Kuan Rd, Taichung 402, Taiwan (China)

    2010-05-15

    Nematode communities from river water and sediments were assessed for the abundance, feeding types, maturity indices and nematode channel ratio (NCR). The sampling sites studied included different levels of pollution and contamination from agricultural, industrial and sewage sources. The nematode abundance found in the sediment samples was more than that in the water samples. The lowest nematode abundance in sediment samples and the lowest NCR in water samples were both found at the industrial pollution site. Water samples showed positive correlation between the NCR and river pollution index (RPI). Mean maturity indices in sediment samples were inversely correlated with RPI. The pollutant source determined the relationship between NCR and pollution level, while maturity index always showed negative correlation with pollutant level regardless of the pollutant sources. The nematode abundance and its community structure were both reliable bioindicators for monitoring long-term river pollution in both qualitative and quantitative aspects. - Nematode community structure in rivers is related to the contamination source and level.

  3. Assessment of nematode community structure as a bioindicator in river monitoring

    International Nuclear Information System (INIS)

    Wu, H.C.; Chen, P.C.; Tsay, T.T.

    2010-01-01

    Nematode communities from river water and sediments were assessed for the abundance, feeding types, maturity indices and nematode channel ratio (NCR). The sampling sites studied included different levels of pollution and contamination from agricultural, industrial and sewage sources. The nematode abundance found in the sediment samples was more than that in the water samples. The lowest nematode abundance in sediment samples and the lowest NCR in water samples were both found at the industrial pollution site. Water samples showed positive correlation between the NCR and river pollution index (RPI). Mean maturity indices in sediment samples were inversely correlated with RPI. The pollutant source determined the relationship between NCR and pollution level, while maturity index always showed negative correlation with pollutant level regardless of the pollutant sources. The nematode abundance and its community structure were both reliable bioindicators for monitoring long-term river pollution in both qualitative and quantitative aspects. - Nematode community structure in rivers is related to the contamination source and level.

  4. Molecular characterization of the Drosophila responses towards nematodes

    OpenAIRE

    Arefin, Md. Badrul

    2016-01-01

    A sophisticated evolutionary conserved innate immune system has evolved in insects to fight pathogens and to restrict damage in harmful (danger) situations including cancer. A significant amount of knowledge about different infection models in Drosophila has been generated in past decades, which revealed functional resemblances and implications for vertebrate systems. However, how Drosophila responds towards multicellular parasitic nematodes and in danger situations is still little understood...

  5. Proteins secreted by root-knot nematodes accumulate in the extracellular compartment during root infection

    OpenAIRE

    Rosso, Marie-Noëlle; Vieira, Paulo; de Almeida-Engler, Janice; Castagnone-Sereno, Philippe

    2011-01-01

    Root-knot nematodes are biotrophic parasites that invade the root apex of host plants and migrate towards the vascular cylinder where they induce the differentiation of root cells into hypertrophied multinucleated giant cells. Giant cells are part of the permanent feeding site required for nematode development into the adult stage. To date, a repertoire of candidate effectors potentially secreted by the nematode into the plant tissues to promote infection has been identified. However, the pre...

  6. Prevalence and intensity of infection with gastrointestinal nematodes in sheep in eastern Serbia

    OpenAIRE

    Kulišić, Z.; Aleksić, Nevenka; Đorđević, M.; Gajić, B.; Tambur, Z.; Stevanović, Jevrosima; Stanimirović, Z.

    2013-01-01

    A coprological examination of 680 grazing sheep was performed in Eastern Serbia from March 2011 to November 2012 in order to determine the presence of gastrointestinal (GI) nematode parasites. Fecal samples were randomly collected and examined by using qualitative and quantitative coprological techniques. It was found that 74.56% sheep were infected. Samples that contained nematode eggs were processed for larval development and eleven nematode genera were i...

  7. Partitioning Yield Loss on Yellow Squash into Nematode and Insect Components

    OpenAIRE

    McSorley, R.; Waddill, V. H.

    1982-01-01

    The effect of a contplex of several insect and nematode pests on yield of yellow squash (Cucurbita pepo L.) was examined in two field tests in southern Florida. Applications of permethrin for insect control and oxamyl primarily for nematode control plus some insect control were made alone and in combination to achieve differential reduction of various insect and nematode components contributing to yield loss. The effect of these components on yield was further analyzed by multiple regression....

  8. A nematode that can manipulate the behaviour of slugs.

    Science.gov (United States)

    Morris, Alex; Green, Michael; Martin, Hayley; Crossland, Katie; Swaney, William T; Williamson, Sally M; Rae, Robbie

    2018-02-27

    The ability of parasites to manipulate the behaviour of their hosts has evolved multiple times, and has a clear fitness benefit to the parasite in terms of facilitating growth, reproduction and transfer to suitable hosts. The mechanisms by which these behavioural changes are induced are poorly understood, but in many cases parasite manipulation of serotonergic signalling in the host brain is implicated. Here we report that Phasmarhabditis hermaphrodita, a parasite of terrestrial gastropod molluscs, can alter the behaviour of slugs. Uninfected slugs (Deroceras panormitanum, Arion subfuscus and Arion hortensis) avoid areas where P. hermaphrodita is present, but slugs infected with P. hermaphrodita are more likely to be found where the nematodes are present. This ability is specific to P. hermaphrodita and other nematodes (Steinernema carpocapsae and Heterorhabditis bacteriophora) do not induce this behavioural change. To investigate how P. hermaphrodita changes slug behaviour we exposed slugs to fluoxetine (a selective serotonin reuptake inhibitor) and cyproheptadine (a serotonin receptor antagonist). Uninfected slugs fed fluoxetine no longer avoided areas where P. hermaphrodita was present; and conversely, infected slugs fed cyproheptadine showed no increased attraction to areas with nematodes. These findings suggest that a possible mechanism by whichP. hermaphrodita is able to manipulate parasite avoidance behaviour in host slugs is by manipulating serotonergic signalling in the brain, and that increased serotonin levels are potentially associated with a reduction in parasite avoidance. Copyright © 2018. Published by Elsevier B.V.

  9. Origanum vulgare (Lamiaceae OVICIDAL POTENTIAL ON GASTROINTESTINAL NEMATODES OF CATTLE

    Directory of Open Access Journals (Sweden)

    Luciana Laitano Dias de Castro

    2013-12-01

    Full Text Available Due to anthelmintic resistance in nematodes, several research studies have been developed seeking control alternatives to these parasites. This study evaluated the in vitro action of Origanum vulgare on gastrointestinal nematode eggs of cattle. In order to evaluate the ability to inhibit egg hatch, different dried leaves extracts of this plant were tested, such as dye, hydroalcoholic and aqueous extracts at concentrations varying from 0.62 to 80 mg/mL. Each assay was accompanied by control containing levamisole hydrochloride (0.2 mg/mL, distilled water and 70 ºGL grain alcohol at the same concentration of the extracts. Test results showed that the different O. vulgare extracts inhibited egg hatch of cattle gastrointestinal nematodes at a percentage that varied from 8.8 to 100%; dye and hydroalcoholic extract were the most promising inhibitors. In view of this ovicidal property, O. vulgare may be an important source of viable antiparasitic compounds for nematodiosis control in ruminants.

  10. Scaleable downstream recovery of nematodes used as biopesticides.

    Science.gov (United States)

    Wilson, J A; Pearce, J D; Ayazi Shamlou, P

    2001-12-20

    This study assesses the suitability of sieving as a scaleable technique for the separation of adult nematodes from infective juveniles, the latter is an effective bioinsecticide whereas the former is waste material resulting from the fermentation process. Batch and semibatch experiments using conventional flow-assisted wet sieving and a novel cross-flow sieving technique were used to study the separation of juveniles from adult nematodes. The experiments were carried out using small-scale devices and the data were analyzed in terms of the screen effectiveness factor. The results were used to identify the sieve size and operating conditions for optimum juvenile recovery. It was found that, for a given species of nematode, optimum recovery was achieved when sieving was carried out in the cross-flow mode, the maximum recovery being a function of the size of the screen. Industrial-scale self-cleaning equipment capable of large-scale continuous screening was used to confirm the capacity of the small-scale operation for scale-up. Experimental results with this unit showed that in continuous operation sieving time is an additional parameter that influences separation performance. Copyright 2001 John Wiley & Sons, Inc.

  11. Influência da adubação e da fumigação do solo, na incidência de nematôides em tubérculos de batatinha Influence of fertilizers and soil fumigation on the nematode incidence of potato tubers

    Directory of Open Access Journals (Sweden)

    O. J. Boock

    1959-01-01

    Full Text Available Dentre as causas que podem levar ao fracasso a cultura da batatinha (Solanum tuberosum L. no Brasil, sobressaem as devidas aos nematóides causadores de galhas ou pipoca Meloidogyne incognita (Kofoide & White, 1919 Chitwood, 1949. Os tubérculos, quando atacados, tornam-se impróprios ao plantio e ao consumo apodrecendo rapidamente. Em vista dêsse fato vêm sendo realizadas, no Instituto Agronômico de Campinas, experiências visando ao combate àquela praga. Os resultados obtidos ultimamente, quando se procurou constatar a influência sôbre a redução da infestação exercida pelas adubações e pelas fumigações do solo com dibrometo de etileno, forneceram os seguintes esclarecimentos: a adubação não exerceu nenhuma influência sôbre o aumento ou diminuição das infestações dos tubérculos pelos nematóides; o dibrometo de etileno mostrou-se eficiente na redução da infestação, na dose de 276 litros por hectare, não devendo, todavia, ser aplicado no terreno no ato do plantio da batatinha mas sim com antecedência de oito ou mais dias; o melhor espaçamento entre aplicações foi o de 20x20 cm; a produção de tubérculos aumentou satisfatoriamente com a fumigação, principalmente quando o nematocida foi aplicado duas vezes no mesmo terreno, isto é, antes de cada uma das culturas ("da sêca" e "das águas".The most important losses caused by root nematodes to the potato crop in the State of Silo Paulo and other parts of Brazil are due to the species Meloidogyne incognita (Kofoide & White, 1919 Chitwood, 1949 and Pralylenchus steineri Lordello, Zamith & Boock, 1954. The former is quite widespread and measures aiming at its control were studied under field conditions. The present paper reports the results on the influence of fertilizer and soil fumigation with ethilene dibromide at 10%, cither separately or combined, on the nematode infestation of the potato yield. The results of the tests showed that the fertilizer application

  12. Gene Silencing and Sex Determination by Programmed DNA Elimination in Parasitic Nematodes

    Science.gov (United States)

    Streit, Adrian; Wang, Jianbin; Kang, Yuanyuan; Davis, Richard E.

    2016-01-01

    Maintenance of genome integrity is essential. However, programmed DNA elimination removes specific DNA sequences from the genome during early development. DNA elimination occurs in unicellular ciliates and diverse metazoa ranging from nematodes to vertebrates. Two distinct groups of nematodes use DNA elimination to silence germline-expressed genes in the soma (ascarids) or for sex determination (Strongyloides spp.). Data suggest that DNA elimination likely evolved independently in these nematodes. Recent studies indicate that differential CENP-A deposition within chromosomes determines which sequences are retained and lost during Ascaris DNA elimination. Additional studies are needed to determine the distribution, functions, and mechanisms of DNA elimination in nematodes. PMID:27315434

  13. The importance, biology and management of cereal cyst nematodes (Heterodera spp.

    Directory of Open Access Journals (Sweden)

    F. Mokrini

    2018-01-01

    Full Text Available Cereals are exposed to biotic and abiotic stresses. Among the biotic stresses, plant-parasitic nematodes play an important role in decreasing crop yield. Cereal cyst nematodes (CCNs are known to be a major constraint to wheat production in several parts of the world. Significant economic losses due to CCNs have been reported. Recognition and identification of CCNs are the first steps in nematode management. This paper reviews the current distribution of CCNs in different parts of the world and the recent advances in nematode identification. The different approaches for managing CCNs are also discussed.

  14. Nematodes as a source of total coliforms in a distribution system.

    Science.gov (United States)

    Locas, Annie; Barbeau, Benoit; Gauthier, Vincent

    2007-05-01

    In a distribution system of a large North American city, recurring total coliforms and atypical coliforms were detected at the exit (distribution pumps) of a storage reservoir. The presence of total coliforms and atypical coliforms was noted when the pumps were in operation and the water temperature was higher than 18 degrees C. The total coliform and atypical coliform concentrations at the volute pump casings ranged from 0 to 93.5 colony forming units (cfu)/100 mL. Significant concentrations of nematodes were also detected at this sampling location, averaging 12.0 nematodes/L in 2001 and 17.4 nematodes/L in 2002. The hypothesis that coliforms were released from the nematodes during their transit through the high-pressure pump was tested by recovering nematodes by filtering large volumes of water and grinding the nematodes in the laboratory, using various techniques. Total coliform and heterotrophic bacteria concentrations ranged from 0 to 27 cfu/nematode and 0 to 643 cfu/nematode, respectively. The origin of the nematodes was traced back to the sand filters located at the two water treatment plants. The importance of invertebrates in the distribution system should not be dismissed and the associated health risks, if any, should be assessed.

  15. EFECTO DEL VERMICOMPOST Y QUITINA SOBRE EL CONTROL DE Meloidogyne incognita EN TOMATE A NIVEL DE INVERNADERO

    Directory of Open Access Journals (Sweden)

    Leida Castro

    2011-01-01

    Full Text Available Meloidogyne incognita es un nematodo endoparásito sedentario, de penetración total y formador de nódulos radicales; tiene una amplia distribución geográfica y causa pérdidas agrícolas importantes. Recientemente se han utilizado abonos orgánicos y compuestos como la quitina en la supresión de plagas y enfermedades de plantas. El objetivo de esta investigación fue evaluar el efecto de la aplicación de vermicompost de estiércol bovino y su enriquecimiento con quitina, sobre la infección de M. incognita en plantas de tomate var. Hayslip bajo condiciones de invernadero. Para esto se inocularon las plantas con 5000 unidades de inóculo (huevos+juveniles en segundo estado por maceta y se compararon con controles que fueron sembrados en suelo sin enmienda orgánica o quitina. La evaluación se llevó a cabo 60 días después y se midió el peso fresco aéreo y radical, peso seco aéreo, población total de nematodos en raíz y suelo, índice de nódulos radicales (INR, índice de masas de huevos (IMH, el factor de reproducción del nematodo (FR y recuento de grupos funcionales (hongos, bacterias y actinomicetes. La adición al suelo de vermicompost provocó un incremento en las variables peso fresco y seco foliar y peso fresco radical: a mayor porcentaje de vermicompost, mayor incremento; así mismo, la aplicación del vermicompost redujo la cantidad del nematodo en raíz y en suelo. La aplicación de quitina acentuó estos resultados, obteniéndose el menor factor de reproducción de M. Incognita, con un valor de 3,76 para la dosis de 50% vermicompost+quitina, mientras que en el testigo este factor fue de 93,20. La aplicación de quitina como enmienda única solo afectó la población de hongos en el suelo, mientras que la de actinomicetes aumentó en los tratamientos enmendados.

  16. DENSIDAD CRÍTICA DE Meloidogyne exigua EN PLANTAS DE ALMÁCIGO DE CAFÉ VARIEDAD CATURRA

    Directory of Open Access Journals (Sweden)

    Mainor Rojas

    2013-01-01

    Full Text Available El objetivo del estudio fue evaluar el efecto de densidad creciente de Meloidogyne exigua sobre el desarrollo de plantas de almácigo. Se trasplantaron plántulas de café variedad caturra a bolsas de polietileno con 1335 cm3 de sustrato desinfectado, para establecer un ensayo con diseño de bloques completos al azar, con 8 repeticiones. Los tratamientos aplicados consistieron de poblaciones iniciales (Pi de 0; 0,125; 0,25; 0,5; 1; 2; 4; 8; 16; 32 y 64 huevos+J2/ cm3 de sustrato, aplicadas un mes después del trasplante. El modelo y=m+(1-m ZP-T aplicado 234 días después del trasplante para la altura, diámetro, número de nudos y peso fresco aéreo, indicó que el límite de tolerancia (T fue de 0,66; 0,06; 0,13 y 0,88 huevos+J2/cm3, respectivamente; la producción mínima relativa (m fue de 0,79; 0,79; 0,33 y 0,54 respectivamente, a Pi iguales o mayores a 64 huevos+J2/cm3. El índice de agallas alcanzó el máximo a partir de una Pi de 2; el pico máximo de nematodos en el suelo y las raíces se alcanzó con Pi entre 2 y 4; mientras la tasa máxima de reproducción fue de 114 con Pi de 0,125. Se concluyó que la densidad crítica fue cercana a cero huevos/cm3 de sustrato como población inicial, y que el almácigo se debe desarrollar libre de nematodos, ya que aún con Pi bajas se puede alcanzar la máxima población en corto tiempo.

  17. Controle alternativo de nematoide das galhas (Meloidogyne incognita raça 2, com óleos essenciais em solo

    Directory of Open Access Journals (Sweden)

    Francisco José Carvalho Moreira

    2015-09-01

    Full Text Available A ação de produtos naturais sobre fitopatógenos tem sido investigada visando-se avaliar sua eficácia no controle alternativo de doenças, principalmente na agricultura orgânica. O objetivo desse trabalho foi avaliar o efeito dos óleos essenciais de alecrim pimenta (Lippia sidoides e capim citronela (Cymbopogonwinterianus no controle de Meloidogyne incognita raça 2, em tomate (Solanumlycopersicum e celósia (Celosia plicata. Para tanto, conduziu-se ensaio em esquema fatorial 6 x 2, com cinco repetições. O ensaio foi realizado em casa de vegetação do Setor de Fitossanidade do Departamento de Fitotecnia/CCA/UFC, no período de abril a junho de 2007. As mudas utilizadas neste ensaio foram transplantadas para vasos plástico contendo 2 kg de solo estéril, nos quais, 24 horas após o transplantio, foram inoculados com 4.000 ovos/J2 de M. incognita, raça 2, exceto as testemunhas negativas. Em 50% do número de vasos, aplicou-se, logo em seguida, 100 ml das soluções de cada óleo essencial em cada vaso na concentração de 2,5 ml L-1. Esperaram-se mais 48 horas para aplicação da mesma quantidade nos vasos restantes. Este volume corresponde a 60% da capacidade de campo desse substrato, que foi previamente calculada. A avaliação final do ensaio deu-se aos 45 dias após a inoculação. Analisou-se em relação ao nematoide: número de galhas (NG, número de ovos (NO, índice de massas de ovos (IMO, fator de reprodução (FR, redução no fator de reprodução (RFR. Quanto ao desenvolvimento das plantas mensurou-se: altura da planta, massa fresca e seca da parte aérea e massa fresca do sistema radicular. Verificou-se que a reprodução do nematoide, mostrou-se menos eficiente em tomate. Os óleos essenciais empregados reduziram a taxa reprodutiva do nematoide em 83 e 29%, em tomate e celósia, respectivamente. As épocas de aplicação dos óleos essenciais diferiram quanto à reprodução do nematoide, para número de galhas e fator de

  18. CHARACTERIZATION OF PHYTOPATHOGENIC FUNGI, BACTERIA, NEMATODES AND VIRUSES IN FOUR COMMERCIAL VARIETIES OF HELICONIA (Heliconia sp. CARACTERIZACIÓN DE HONGOS, BACTERIAS, NEMÁTODOS Y VIRUS FITOPATÓGENOS EN CUATRO VARIEDADES COMERCIALES DE HELICONIA (Heliconia sp.

    Directory of Open Access Journals (Sweden)

    Nathali López Cardona

    2012-06-01

    Full Text Available Abstract. Analysis of 914 samples of roots, rhizomes, pseudostems, inflorescences and leaves of four commercial varieties of heliconia, cultivated at the municipality of Chinchiná-Caldas (Colombia, allowed to identify five genera of plant pathogenic fungi (Rhizoctonia, Fusarium, Colletotrichum, Helminthosporium and Curvularia, three genera of plant pathogenic bacteria (Ralstonia, Pseudomonas and Erwinia, two species of viruses (Banana streak virus (BSV, Badnavirus, and Cucumber mosaic virus (CMV, Cucumovirus,, and seven genera of plant parasitic nematodes (Helicotylenchus, Tylenchus, Meloidogyne, Ditylenchus, Aphelenchoides, Pratylenchus, and Radopholus. Of these, Fusarium sp., affecting pseudostems, Pseudomonas sp., affecting leaves and inflorescences, and the plant parasitic nematodes Ditylenchus sp., Aphelenchoides sp., Pratylenchus sp. and Radopholus sp., are new records in the heliconia production in Colombia . The most limiting diseases corresponded to leaf blight, caused by Helminthosporium sp.; the bacterioses, caused by Pseudomonas sp.; the spotted stems, caused by Fusarium sp.; and soft rot of the pseudostems, caused by Erwinia sp. The pathogenicity tests demonstrated that Colletotrichum sp. and Phoma sp. are not pathogenic in leaves; while Fusarium sp., inoculated in pseudostems, Helminthosporium sp. and Pseudomonas sp., inoculated in leaves, and Colletotrichum sp. and Pseudomonas sp., inoculated in inflorescences, had incidence values of 83.3, 86.6, 93.3, 100.0 and 100.0%, respectively.Resumen. El análisis de 914 muestras de raíces, rizomas, pseudotallos, inflorescencias y hojas de cuatro variedades comerciales de heliconia, cultivadas en el municipio de Chinchiná-Caldas (Colombia, permitieron identificar cinco géneros de hongos fitopatógenos (Rhizoctonia, Fusarium, Colletotrichum, Helminthosporium y Curvularia, tres géneros de bacterias fitopatógenas (Ralstonia, Pseudomonas y Erwinia, dos especies de virus (Banana streak

  19. Soil nematode assemblages as bioindicators of radiation impact in the Chernobyl Exclusion Zone

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte-Pradines, C., E-mail: catherine.lecomte-pradines@irsn.fr [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Bonzom, J.-M. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Della-Vedova, C. [Magelis, 6, rue Frederic Mistral, 84160 Cadenet (France); Beaugelin-Seiller, K. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LM2E, Building 159, Cadarache 13115 Saint Paul lez Durance cedex (France); Villenave, C. [ELISOL Environment, Building 12, Campus de la Gaillarde, 2 place Viala, 34060 Montpellier cedex 2 (France); Gaschak, S. [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Coppin, F. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, L2BT, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Dubourg, N. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, GARM Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Maksimenko, A. [Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, 07100 Slavutych (Ukraine); Adam-Guillermin, C. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, LECO, Building 186, Cadarache 13115 Saint Paul lez Durance cedex (France); Garnier-Laplace, J. [Institute for Radioprotection and Nuclear Safety, IRSN/PRP-ENV/SERIS, Building 159, Cadarache 13115 Saint Paul lez Durance cedex (France)

    2014-08-15

    In radioecology, the need to understand the long-term ecological effects of radioactive contamination has been emphasised. This requires that the health of field populations is evaluated and linked to an accurate estimate of received radiological dose. The aim of the present study was to assess the effects of current radioactive contamination on nematode assemblages at sites affected by the fallout from the Chernobyl accident. First, we estimated the total dose rates (TDRs) absorbed by nematodes, from measured current soil activity concentrations, Dose Conversion Coefficients (DCCs, calculated using EDEN software) and soil-to-biota concentration ratios (from the ERICA tool database). The impact of current TDRs on nematode assemblages was then evaluated. Nematodes were collected in spring 2011 from 18 forest sites in the Chernobyl Exclusion Zone (CEZ) with external gamma dose rates, measured using radiophotoluminescent dosimeters, varying from 0.2 to 22 μGy h{sup −1}. These values were one order of magnitude below the TDRs. A majority of bacterial-, plant-, and fungal-feeding nematodes and very few of the disturbance sensitive families were identified. No statistically significant association was observed between TDR values and nematode total abundance or the Shannon diversity index (H′). The Nematode Channel Ratio (which defines the relative abundance of bacterial- versus fungal-feeding nematodes) decreased significantly with increasing TDR, suggesting that radioactive contamination may influence nematode assemblages either directly or indirectly by modifying their food resources. A greater Maturity Index (MI), usually characterising better soil quality, was associated with higher pH and TDR values. These results suggest that in the CEZ, nematode assemblages from the forest sites were slightly impacted by chronic exposure at a predicted TDR of 200 μGy h{sup −1}. This may be imputable to a dominant proportion of pollutant resistant nematodes in all sites

  20. Sensory interaction between attractant diacetyl and repellent 2-nonanone in the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Matsuura, Tetsuya; Izumi, Junichi; Hioki, Mamoru; Nagaya, Hiroki; Kobayashi, Yasuaki

    2013-06-01

    In the nematode Caenorhabditis elegans, the odorant diacetyl is sensed by AWA sensory neurons in the amphid sensory organ and elicits an attractive response, whereas 2-nonanone is sensed by AWB amphid sensory neurons and elicits an avoidance response. In the present study, we report that nematodes exhibit a sensory interaction between the attractant diacetyl and repellent 2-nonanone. In the presence of food, the chemotactic response to 0.01% diacetyl in nematodes preexposed to 0.1% diacetyl was greater than that in nonexposed naive nematodes (P < 0.05). The response to diacetyl was also greater in nematodes preexposed to 3% 2-nonanone in the presence of food than that in naive nematodes (P < 0.01). In the absence of food, the response to diacetyl in nematodes preexposed to diacetyl or 2-nonanone was significantly lower than that in nonexposed control nematodes (P < 0.01). The avoidance response to 10% 2-nonanone in nematodes preexposed to each odorant in the presence or absence of food was lower than that in nonexposed nematodes (P < 0.05). To confirm the validity of our results, the chemotactic responses to diacetyl and 2-nonanone were observed using che-3, odr-4, and odr-10 mutants, which exhibited defective sensitivity to diacetyl or 2-nonanone. From the results of our experiments, we conclude that nematodes exhibit a sensory interaction between diacetyl and 2-nonanone and speculate that this interaction is driven by higher-level neuronal circuits that underlie sensory integration. Copyright © 2013 Wiley Periodicals, Inc.