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Sample records for meloidogyne incognita population

  1. Molecular Comparison of Iranian Populations of Meloidogyne javanica and Meloidogyne incognita with PCR-RFLP

    M. Mohammadi

    2007-01-01

    Full Text Available To carry out this study, total DNA was extracted from eggs and from second stage juveniles of several populations of Meloidogyne javanica and Meloidogyne incognita, using phenol / chloroform method. Following extraction, DNA was electrophoresed on 1% agarose gel to determine its quality and quantity. A specific primer pair (C2F3 / 1108; 23 and 20 nucleotides, respectively was used to discriminate M. javanica from M. incognita populations using polymerase chain reaction (PCR. Primer annealing sites were located in the 3? portion of mitochondrial gene encoding cytochrome oxidase subunit II (COII and in the 16S rRNA gene. Following PCR amplification, electrophoresis of amplified DNA showed 1.7 kb fragment in populations of both species. Digestion of 1.7 kb amplified product with HinfI restriction endonuclease resulted in the generation of two DNA fragments of 0.7 and 1.0 kb in M. javanica and three DNA fragments of 0.3, 0.4 and 1.0 kb in M. incognita. There were no differences in the digestion patterns among various populations of each species examined.

  2. Influence of Initial Population Densities of Meloidogyne incognita on Three Chile Cultivars

    Lindsey, D. L.; Clayshulte, Margaret Stefano

    1982-01-01

    The effects of Meloidogyne incognita on the Big Jim, Jalapeno, and New Mexico No. 6 chile (Capsicum annuum) cultivars were investigated in microplots for two growing seasons. All three cultivars were susceptible to M. incognita and reacted similarly to different initial populations of this nematode. Severe stunting and yield suppressions occurred at all initial M. incognita densities tested ranging from 385 to 4,230 eggs and larvae/500 cm³ soil. Regression analysis of the microplot data from ...

  3. Relationship Between Egg Viability and Population Densities of Meloidogyne incognita on Cotton

    Starr, J. L.

    1988-01-01

    Cotton seedlings were inoculated with a range of initial populations (Pi) of Meloidogyne incognita in greenhouse experiments to test the relationship between nematode population densities and egg viability. In two of three experiments, a significant (P < 0.05) negative linear relationship was detected between percentage of hatch of first generation eggs and log Pi. A similar relationship between hatch and root-gall index was observed. In two experiments numbers of eggs judged to be nonviable ...

  4. Effect of different initial population densities of Meloidogyne incognita on the growth of Cicer arietinum.

    Hesamedin, R

    2006-01-01

    Studies were undertaken to determine the effect of different initial population densities (Pi = 50, 100, 250, 500, 1000, 2500, 5000, 10,000 and 15,000 J2/Pot) of Meloidogyn incognita on chikpea cv. Bandal local in a pot experiment. Plant growth, flowering and pod bearing were influenced by all the initial population densities. Increase in Pi not only resulted in proportional decrease in plant lenght, fresh weight, dry weight and pod bearing but also delayed the flowering. The highest reduction was observed at the initial population of 15000 as compared to uninoculated control. It was noticed that reduction in root fresh weight was less than shoot especially at higher initial population. Reproduction of nematode was observed inversely proportional to intial population (on 50 J2/Pot, Rf = 196.64 and 15000 J2/Pot, Rf = 3.60). PMID:17390808

  5. Characterization of resistance breaking Meloidogyne incognita - like populations using lectins, monoclonal antibodies and spores of Pasteuria penetrans

    Fargette, Mireille; Davies, K G; Robinson, M.P.; Trudgill, D. L.

    1994-01-01

    Six clones de #Meloidogyne$, provenant de populations récoltées en Côte d'Ivoire et qui possèdent un phénotype estérasique particulier (codé pVI) ainsi que la faculté de briser la résistance conférée par le gène #Mi$, ont été comparés à #M. incognita$ à l'aide de différentes sondes. Le marquage à l'aide de lectines des exsudats amphidiaux de juvéniles de second stade ne permet pas de distinguer ces lignées de #M. incognita$. Des souches de #Pasteuria penetrans$ permettent de les distinguer et...

  6. Mitochondrial DNA length variation in Meloidogyne incognita isolates of established genetic relationships : utility for nematode population studies

    Whipple, L.E.; Lunt, D.H.; Hyman, B. C.

    1998-01-01

    Six isolats de #Meloidogyne incognita$, dont les relations génétiques ont été précédemment établies, sont utilisés pour tester l'utilité d'une "répétition de tandems en nombre variable" (VNTR) d'une valeur de 63 paires de bases mitochondriales comme marqueurs en vue d'étude de populations. La réaction en chaîne de polymérase (PCR) est utilisée pour amplifier ce locus et mesurer le nombre de copies et la fréquence des allèles des VNTR à 63 paires de bases. Les individus du nématode sont typiqu...

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

    Southern root-knot nematode (Meloidogyne incognita) is a serious pest of cultivated watermelon (Citrullus lanatus var. lanatus) in southern regions of the US and no resistance is known to exist in commercial watermelon cultivars. Wild watermelon relatives (C. lanatus var. citroides) have been shown...

  8. Competition of Meloidogyne incognita and Rotylenchulus reniformis on Cotton Following Separate and Concomitant Inoculations

    Diez, Asdrubal; Lawrence, G. W.; Lawrence, K. S.

    2003-01-01

    It has been hypothesized Rotylenchulus reniformis (Rr) has a competitive advantage over Meloidogyne incognita (Mi) in the southeastern cotton production region of the United States. This study examines the reproduction and development of Meloidogyne incognita (Mi) and Rotylenchulus reniformis (Rr) in separate and concomitant infections on cotton. Under greenhouse conditions, cotton seedlings were inoculated simultaneously with juveniles (J2) of M. incognita and vermiform adults of R. reniformis in the following ratios (Mi:Rr): 0:0, 100:0, 75:25, 50:50, 25:75, and 0:100. Soil populations of M. incognita and R. reniformis were recorded at 3, 6, 9, 14, 19, 25, 35, 45, and 60 days after inoculations. At each date, samples were taken to determine the life stage of development, number of egg masses, eggs per egg mass, galls, and giant cells or syncytia produced by the nematodes. Meloidogyne incognita and R. reniformis were capable of initially inhibiting each other when the inoculum ratio of one species was higher than the other. In concomitant infections, M. incognita was susceptible to the antagonistic effect of R. reniformis. Rotylenchulus reniformis affected hatching of M. incognita eggs, delayed secondary infection of M. incognita J2, reduced the number of egg masses produced by M. incognita, and reduced J2 of M. incognita 60 days after inoculations. In contrast, M. incognita reduced R. reniformis soil populations only when its proportion in the inoculum ratio was higher than that of R. reniformis. Meloidogyne incognita reduced egg masses produced by R. reniformis, but not production of eggs and secondary infection. PMID:19262774

  9. Meloidogyne incognita Surface Antigen Epitopes in Infected Arabidopsis Roots

    Gravato-Nobre, M. J.; McClure, M A; DOLAN, L; Calder, G.; Davies, K.G.; B. Mulligan; Evans, K; Von Mende, N.

    1999-01-01

    Surface-coat epitopes of Meloidogyne incognita were detected in root tissues of Arabidopsis thaliana during migration and feeding site formation. A whole-mount root technique was used for immunolocalization of surface coat epitopes in A. thaliana, with the aid of a monoclonal antibody raised specifically against the outer surface of infective juveniles of M. incognita. The antibody, which was Meloidogyne-specific, recognized a fucosyl-bearing glycoprotein in the surface coat. During migration...

  10. Adaptação hospedeira de variedades de abacaxi a meloidogyne incognita raça 1 Host suitability of pineapple varieties for meloidogyne incognita race 1

    Leila Lucí Dinardo-Miranda

    1996-01-01

    Full Text Available Avaliou-se, em campo naturalmente infestado, a adaptação hospedeira das variedades de abacaxi Smooth Cayenne, Abacaxi-de-gomo, Bico-de-rosa, Boituva, Guiana, Huitota, Manzana, Natal Queen, Pérola, Perolera, Rondon, Roxo-de-Tefé e Turi Verde a Meloidogyne incognita raça 1. Somente 'Huitota' apresentou populações do nematóide significativamente menores que aquelas encontradas na 'Smooth Cayenne', considerada boa hospedeira da espécie.The host suitability of thirteen pineapple varieties, namely Smooth Cayenne, Abacaxi-de-gomo, Bico-de-rosa. Boituva, Guiana, Huitota, Manzana, Natal Queen, Pérola, Perolera, Rondon, Roxo-de-Tefé, and Turi Verde, for Meloidogyne incognita race I was evaluated under infested field conditions. Only 'Huitota' was considered poor host, showing significantly lower nematode population than 'Smooth Cayenne', known as a good host to M. incognita.

  11. Effects of a wild type strain and a mutant strain of the fungus Verticillium lecanii on Meloidogyne incognita populations in greenhouse studies

    Meyer, S. L. F.

    1994-01-01

    La capacité d'une souche de #Verticillium lecanii$ et celle d'un mutant induit par les UV à réduire des populations de #Meloidogyne incognita$ sur des plants de tomates ont été testées. Les deux souches ont été incorporées à un mélange de son et d'alginate, et trois taux - 0,0009 %, 0,002 % et 0,02 % de poids sec de champignon par poids de sol - ont été placés à proximité des racines. La souche mutante a été également testée aux taux de 0,002 et 0,006 %. Le nombre d'oeufs et de juvéniles a ét...

  12. Nutsedge Counts Predict Meloidogyne incognita Juvenile Counts in an Integrated Management System.

    Ou, Zhining; Murray, Leigh; Thomas, Stephen H; Schroeder, Jill; Libbin, James

    2008-06-01

    The southern root-knot nematode (Meloidogyne incognita), yellow nutsedge (Cyperus esculentus) and purple nutsedge (Cyperus rotundus) are important pests in crops grown in the southern US. Management of the individual pests rather than the pest complex is often unsuccessful due to mutually beneficial pest interactions. In an integrated pest management scheme using alfalfa to suppress nutsedges and M. incognita, we evaluated quadratic polynomial regression models for prediction of the number of M. incognita J2 in soil samples as a function of yellow and purple nutsedge plant counts, squares of nutsedge counts and the cross-product between nutsedge counts . In May 2005, purple nutsedge plant count was a significant predictor of M. incognita count. In July and September 2005, counts of both nutsedges and the cross-product were significant predictors. In 2006, the second year of the alfalfa rotation, counts of all three species were reduced. As a likely consequence, the predictive relationship between nutsedges and M. incognita was not significant for May and July. In September 2006, purple nutsedge was a significant predictor of M. incognita. These results lead us to conclude that nutsedge plant counts in a field infested with the M. incognita-nutsedge pest complex can be used as a visual predictor of M. incognita J2 populations, unless the numbers of nutsedge plants and M. incognita are all very low. PMID:19259526

  13. Reao de gentipos de maracujazeiro a Meloidogyne incognita raa 3 e Meloidogyne javanica / Reaction of passion fruit genotypes to Meloidogyne incognita race 3 and Meloidogyne javanica

    Leandro Souza, Rocha; Regina Cssia Ferreira, Ribeiro; Adelica Aparecida, Xavier; Fabola de Jesus, Silva; Claudio Horst, Bruckner.

    2013-12-01

    Full Text Available O objetivo do trabalho foi avaliar a reao de gentipos de maracujazeiro a Meloidogyne spp.. O experimento foi conduzido em casa de vegetao em DBC, com seis repeties, em esquema fatorial 9x2 (Passiflora giberti, P. nitida, P. setacea, P. mucronata, P. cincinnata, P. ligularis, P.alata, hbrido [...] BRS Sol do Cerrado e seleo M19-UFV x Meloidogyne javanica e M. incognita raa 3). Segundo os critrios de Oostenbrink, e Moura e Rgis, o BRS Sol do Cerrado, a seleo M-19-UFV e P. alata comportaram-se como imunes a M. incognita. Alm 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 gentipos classificados como imunes pelos outros critrios foram classificados como resistentes aos nematoides. Todas as variveis nematolgicas 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 nmero de galhas, massas de ovos, ovos, J2 e FR, em relao aos outros gentipos. O peso de matria fresca de raiz de P. ligularis e P. mucronata foi menor na presena de M. incognita em relao a M. javanica. Abstract in english The aim of this study was to evaluate the reaction of genotypes of passion fruit to Meloidogyne spp.. The experiment was carried out in a greenhouse in RBD with six replications in 9 x 2 factorial designs (Passiflora giberti, P. nitida, P. setacea, P. mucronata, P. cincinnata, P. ligularis, P. alata [...] , BRS Sol do Cerrado cultivar and selection M19-UFV x Meloidogyne javanica and M. incognita race 3). According to Oostenbrink criteria, and Moura and Rgis, the BRS Sol do Cerrado, and selection M-19-UFV and P. alata behaved as immune to M. incognita. In addition to these, P. cincinnata and P. setacea were immune to M. javanica. Passiflora cincinnata and P.giberti behaved as resistant to M. incognita and M. javanica, respectively. According to Taylor and Sasser, the genotypes classified as immune by the other criteria were classified as resistant to nematodes. All the nematological variables evaluated in P. giberti, P. ligularis, P. mucronata and P. nitida were superior in plants infected by M. incognita. Regardless of the nematode, P mucronata presented larger number of root galls, egg masses, eggs, J2 and RF, as compared to the other genotypes. The root fresh matter weight of P. ligularis and P. mucronata was smaller in the presence of M. incognita as compared to M. javanica.

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

    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)

  15. GENOTYPIC DIVERSITY OF POTATO GERMPLASM AGAINST ROOT KNOT NEMATODE (MELOIDOGYNE INCOGNITA INFECTION IN PAKISTAN

    Sajid A. Khan

    2012-12-01

    Full Text Available Potato (Solanum tuberosum, an important vegetable crop of Pakistan endures significant yield losses due to root knot nematode (Meloidogyne incognita.. Research wok was designed to identify resistant potato germplasm against RKN (Meloidogyne incognita infection. A field trial was conducted in the research area of Department of Plant Pathology, University of Agriculture Faisalabad. Thirty six (36 potato verities/ cultivars relocated five times were sown in four years sick plot containing root knot nematode (Meloidogyne incognita in RCBD layout. Root knot nematode reproduction and host damage was accessed by recording nematode root galls and egg mass indices, root weight, shoot weight, , number of leaves, fruit weight, rate of reproduction and final population of nematodes. Experiment revealed a considerable variation in response against Meloidogyne incognita infection among the genotype tested but none of the single cultivar was immune. FD-8-1 was used as negative control. The cultivar FD-19-2 was highly susceptible followed by SH-692 and SH-5. All other cultivars had less galling index with low fecundity rate indicating their ability to suppress the adult female reproduction. The cultivar FD-1-3 scored least number of galls and egg mass indices followed by FD-49-62, SH-339 and SH-332.

  16. Meloidogyne incognita Surface Antigen Epitopes in Infected Arabidopsis Roots

    Gravato-Nobre, M. J.; McClure, M. A.; Dolan, L.; Calder, G.; Davies, K. G.; Mulligan, B.; Evans, K.; von Mende, N.

    1999-01-01

    Surface-coat epitopes of Meloidogyne incognita were detected in root tissues of Arabidopsis thaliana during migration and feeding site formation. A whole-mount root technique was used for immunolocalization of surface coat epitopes in A. thaliana, with the aid of a monoclonal antibody raised specifically against the outer surface of infective juveniles of M. incognita. The antibody, which was Meloidogyne-specific, recognized a fucosyl-bearing glycoprotein in the surface coat. During migration in host tissues the surface coat was shed, initially accumulating in the intercellular spaces next to the juvenile and later at cell junctions farther from the nematode. Upon induction of giant cell formation, the antibody bound to proximally located companion cells and sieve elements of the phloem. PMID:19270892

  17. Evaluation of Asteraceae Plants for Control of Meloidogyne incognita.

    Tsay, T T; Wu, S T; Lin, Y Y

    2004-03-01

    Of the 56 species and 43 genera of Asteraceae tested, 9 were highly resistant or immune to Meloidogyne incognita and did not form root galls. Twenty-six species and six cultivars had 25% or fewer roots galled and were considered moderately resistant to M. incognita. Pre-planting Cosmos bipinnatus (F190), Gaillardia pulchella, Tagetes erecta, Tithonia diversifolia, or Zinnia elegans (F645) reduced root galling and M. incognita J2 in and around Ipomoea reptans. Amendment of soils with roots, stems, or leaves of G. pulchella was effective in controlling M. incognita on I. reptans. Tissue extracts of G. pulchella were lethal to various plant-parasitic nematodes but were innocuous to free-living nematodes. Root exudates of G. pulchella were lethal to J2 of M. incognita and were inhibitory to the hatch of eggs at the concentration of 250 ppm or higher. Gaillardia pulchella could be used to manage M. incognita as a rotation crop, a co-planted crop, or a soil amendment for control of root-knot nematode. PMID:19262785

  18. Efectividad biolgica de extractos de Carya illinoensis, para el control de Meloidogyne incognita / Biological effectiveness of Carya illinoensis extracts for Meloidogyne incognita management

    Fabiola, Garrido Cruz; Melchor, Cepeda Siller; Francisco Daniel, Hernndez Castillo; Yisa Mara, Ochoa Fuentes; Ernesto, Cerna Chvez; Diana Margarita, Morales Adame.

    2014-11-01

    Full Text Available El trabajo se desarroll durante 2012 en el Laboratorio de Nematologa de la Universidad Autnoma Agraria Antonio Narro, con el objetivo de evaluar extractos vegetales derivados del nogal Carya illinoinensis (Wangenh) K. Koch, para el control del nematodo agallador Meloidogyne sp. Gldi 1889. Los ne [...] matodos fueron obtenidos a partir de tubrculos de papa (Solanum tuberosum L.) Var. "Alpha", que presentaban sintomatologa. Se realiz la identificacin de los nematodos y se determin que correspondan a Meloidogyne incognita. Para el estudio de evaluaci de efectividad biolgica de los extractos se colocaron los extractos a diferentes concentraciones, (1.0, 1.5 y 2%) utilizando una poblacin de 30 5 especmenes de Meloidogyne incognita activos, se estableci un experimento completamente al azar, con once tratamientos incluyendo al testigo y cinco repeticiones. Se observaron al microscopio estereoscpico a las 24, 48 y 72 h de exposicin con los extractos, para determinar el porcentaje de mortalidad. De los extractos evaluados, los que presentaron mayor actividad nematicida fueron el FIM8 (ruezno acuoso) con 89.16%, FIM6 (Ruezno etanoltico) con 69.22%, y el FIM7 (Cscara acuoso) con 60.77%, todos stos en la concentracin al 2% y en la observacin a las 72 h de exposicin con el extracto. Abstract in english The work was developed in 2012 at the Nematology Laboratory of the Universidad Autonoma Agraria Antonio Narro, with the aim of evaluating plant extracts derived hickory Carya illinoinensis (Wangenh) K. Koch, for the root-knot nematode Meloidogyne sp. Gldi (1889) management. Nematodes were obtained [...] from potato tubers (Solanum tuberosum L.) Var. "Alpha", presenting symptoms. Identification of nematodes was performed and it was determined that corresponded to Meloidogyne incognita. Assessment study for the biological effectiveness of the extracts extracts were placed at different concentrations (1.0, 1.5 and 2%) using a population of 30 5 Meloidogyne incognita specimens of assets, an experiment was completely randomized, with eleven treatments including control and five replications. Stereoscopic microscope at 24, 48 and 72 h of exposure to the extracts were observed to determine the percentage of mortality. Of the extracts tested, those with higher nematicidal activity were FIM8 (aqueous husk) with 89.16%, FIM6 (etanoltico husk) with 69.22%, and FIM7 (aqueous shell) with 60.77%, all these in the concentration of 2% and observation at 72 h of exposure to the extract.

  19. Patogenicidade de Meloidogyne exigua e M. incognita raça 1 a mudas de cafeeiros Pathogenicity of Meloidogyne exigua and M. incognita race 1 to coffee seedlings

    Wallace Gonçalves

    1996-01-01

    Full Text Available O presente trabalho teve por objetivo avaliar os danos causados por Meloidogyne exigua e M. incognita raça 1 a mudas de cafeeiros (Coffea spp. Coffea arabica cv. Mundo Novo (LCP 515-20 e de C. canephora cv. Robusta (C 2258. O ensaio foi desenvolvido em casa de vegetação, em vasos de um litro, contendo uma plântula cada um. Aos vinte dias após o transplante, as plântulas foram inoculadas separadamente com 0, 2.000, 4.000 e 8.000 ovos de cada nemat��ide. As populações dos parasitos nas raízes e alguns parâmetros de crescimento das plantas foram avaliados aos 150 dias da inoculação. Verificou-se que M. incognita raça 1 foi mais patogênica que M. exigua ao cultivar Mundo Novo. O cafeeiro C 2258 comportou-se como hospedeiro não eficiente (FR In order to evaluate the damage caused by Meloidogyne incognita race 1 and M. exigua to C. arabica cv. Mundo Novo and C. canephora cv. Robusta (C 2258 an experiment was established under greenhouse conditions, with 0, 2,000, 4,000, and 8,000 eggs as inicial inoculum, in a completely randomized design with one plant per plot. The plants were inoculated 20 days after transplanting and nematode population and some growth parameters were evaluated 150 days later. M. incognita race 1 showed to be more pathogenic to 'Mundo Novo' than M. exigua. The selection C 2258 was not an efficient host for M. incognita race 1, although reproduction occurred and significant reduction in the shoot dry weight of the inoculated plants was determined; M. exigua did not infect this cultivar.

  20. Effects of Soil Compaction and Meloidogyne incognita on Cotton Root Architecture and Plant Growth

    Ma, Jianbing; Kirkpatrick, Terrence L.; Rothrock, Craig S.; Brye, Kristofor

    2013-01-01

    The effects of a soil hardpan and Meloidogyne incognita on cotton root architecture and plant growth were evaluated in microplots in 2010 and 2011. Soil was infested with M. incognita at four different levels with or without a hardpan. The presence of a hardpan resulted in increased plant height, number of main stem nodes, and root fresh weight for cotton seedlings both years. Meloidogyne incognita decreased height and number of nodes for seedlings in 2010. Nematode infestation increased seed...

  1. Competition of Meloidogyne incognita and Rotylenchulus reniformis on Cotton Following Separate and Concomitant Inoculations

    Diez, Asdrubal; Lawrence, G. W.; Lawrence, K. S.

    2003-01-01

    It has been hypothesized Rotylenchulus reniformis (Rr) has a competitive advantage over Meloidogyne incognita (Mi) in the southeastern cotton production region of the United States. This study examines the reproduction and development of Meloidogyne incognita (Mi) and Rotylenchulus reniformis (Rr) in separate and concomitant infections on cotton. Under greenhouse conditions, cotton seedlings were inoculated simultaneously with juveniles (J2) of M. incognita and vermiform adults of R. reniform...

  2. Meloidogyne incognita nematode resistance QTL in carrot

    Root-knot nematodes (Meloidogyne spp.) are major pests attacking carrots (Daucus carota) worldwide, causing galling and forking of the storage roots, rendering them unacceptable for market. Genetic resistance could significantly reduce the need for broad-spectrum soil fumigants in carrot production....

  3. Reao de gentipos de maracujazeiro a Meloidogyne incognita raa 3 e Meloidogyne javanica

    Leandro Souza Rocha

    2013-12-01

    Full Text Available O objetivo do trabalho foi avaliar a reao de gentipos de maracujazeiro a Meloidogyne spp.. O experimento foi conduzido em casa de vegetao em DBC, com seis repeties, em esquema fatorial 9x2 (Passiflora giberti, P. nitida, P. setacea, P. mucronata, P. cincinnata, P. ligularis, P.alata, hbrido BRS Sol do Cerrado e seleo M19-UFV x Meloidogyne javanica e M. incognita raa 3. Segundo os critrios de Oostenbrink, e Moura e Rgis, o BRS Sol do Cerrado, a seleo M-19-UFV e P. alata comportaram-se como imunes a M. incognita. Alm 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 gentipos classificados como imunes pelos outros critrios foram classificados como resistentes aos nematoides. Todas as variveis nematolgicas 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 nmero de galhas, massas de ovos, ovos, J2 e FR, em relao aos outros gentipos. O peso de matria fresca de raiz de P. ligularis e P. mucronata foi menor na presena de M. incognita em relao a M. javanica.

  4. Pasteuria penetrans for Control of Meloidogyne incognita on Tomato and Cucumber, and M. arenaria on Snapdragon.

    Kokalis-Burelle, Nancy

    2015-09-01

    Meloidogyne incognita and Meloidogyne arenaria are important parasitic nematodes of vegetable and ornamental crops. Microplot and greenhouse experiments were conducted to test commercial formulations of the biocontrol agent Pasteuria penetrans for control of M. incognita on tomato and cucumber and M. arenaria on snapdragon. Three methods of application for P. penetrans were assessed including seed, transplant, and post-plant treatments. Efficacy in controlling galling and reproduction of the two root-knot nematode species was evaluated. Seed treatment application was assessed only for M. incognita on cucumber. Pasteuria treatment rates of a granular transplant formulation ranged from 1.5 × 10(5) endospores/cm(3) to 3 × 10(5) endospores/cm(3) of transplant mix applied at seeding. Additional applications of 1.5 × 10(5) endospores/cm(3) of soil were applied as a liquid formulation to soil post-transplant for both greenhouse and microplot trials. In greenhouse cucumber trials, all Pasteuria treatments were equivalent to steamed soil for reducing M. incognita populations in roots and soil, and reducing nematode reproduction and galling. In cucumber microplot trials there were no differences among treatments for M. incognita populations in roots or soil, eggs/g root, or root condition ratings. Nematode reproduction on cucumber was low with Telone II and with the seed treatment plus post-plant application of Pasteuria, which had the lowest nematode reproduction. However, galling for all Pasteuria treatments was higher than galling with Telone II. Root-knot nematode control with Pasteuria in greenhouse and microplot trials varied on tomato and snapdragon. Positive results were achieved for control of M. incognita with the seed treatment application on cucumber. PMID:26527842

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

    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. Response of Tomato Cultigens to Meloidogyne javanica and Races of Meloidogyne incognita

    Khan, Arbrar Ahmad; Khan, M. Wajid

    1991-01-01

    Thirty-six cultigens of tomato were evaluated for resistance against Meloidogyne javanica and four races of M. incognita with standards and parameters adopted by the International Meloidogyne Project. Most cultigens were susceptible to the nematodes, including some that were previously reported to be resistant to these nematodes. Ten accessions, namely Pusa-120, Calmart VFN, Panjab 6.NR-7, EC173898 (72T6), EC173897 (Cal-Mart), EC173896 (Kewalo), CLN363BC?F?-167-1-0, CLN363BC?F?-190-1-0, CLN36...

  7. Cyperus Tubers Protect Meloidogyne incognita from 1,3-Dichloropropene.

    Thomas, S H; Schroeder, J; Murray, L W

    2004-06-01

    Meloidogyne incognita-infected and noninfected tubers of yellow nutsedge (Cyperus esculentus) and purple nutsedge (Cyperus rotundus) were treated with 56 L/ha 1,3-dichloropropene (1,3-D) in microplots and subsequently examined for tuber and nematode viability in the greenhouse using a chile pepper (Capsicum annuum) bioassay system. The study was conducted three times. Nutsedge tuber viability and M. incognita harbored in both yellow and purple nutsedge tubers were unaffected by 1,3-D treatment. Nematode reproduction on nutsedges and associated chile pepper plants varied among years, possibly due to differing levels of tuber infection or soil temperature, but was not affected by fumigation. The presence of M. incognita resulted in greater yellow nutsedge tuber germination and reproduction. The efficacy of 1,3-D for management of M. incognita in chile pepper production is likely to be reduced when nutsedges are present in high numbers, reinforcing the importance of managing these weeds and nematodes simultaneously. PMID:19262797

  8. Alternate row placement is ineffective for cultural control of Meloidogyne incognita in cotton

    Davis, Richard F.

    2008-01-01

    The objective of this study was to determine if planting cotton into the space between the previous year's rows reduces crop loss due to Meloidogyne incognita compared to planting in the same row every year. Row placement had a significant (P ≤ 0.05) effect on nematode population levels only on 8 July 2005. Plots receiving 1,3-dichloropropene plus aldicarb had lower nematode population levels than non-fumigated plots on 24 May and 8 July in 2005, but not in 2004. The effect of nematicide trea...

  9. Influence of Environmental Factors on the Hatch and Survival of Meloidogyne incognita

    Goodell, P. B.; Ferris, H.

    1989-01-01

    The influence of soil temperature and moisture on Meloidogyne incognita (Kofoid and White) Chitwood was examined in relation to hatching and survival of second-stage juveniles (J2). Nematodes were cultured on cotton (Gossypium hirsutum L. cv. Acala SJ2) under field conditions to provide populations similar to those found in the field in late autumn. Egg masses were placed in a temperature range (9-12 C and 21 C), and hatch was measured over a period equivalent to 20 degree days > 10 C (DD10)....

  10. Reducing Meloidogyne incognita Injury to Cucumber in a Tomato-Cucumber Double-Cropping System

    Colyer, P. D.; Kirkpatrick, T. L.; Vernon, P. R.; Barham, J. D.; Bateman, R.J.

    1998-01-01

    The effects of a root-knot nematode-resistant tomato cultivar and application of the nematicide ethoprop on root-knot nematode injury to cucumber were compared in a tomato-cucumber double-cropping system. A root-knot nematode-resistant tomato cultivar, Celebrity, and a susceptible cultivar, Heatwave, were grown in rotation with cucumber in 1995 and 1996. Celebrity suppressed populations of Meloidogyne incognita in the soil and resulted in a low root-gall rating on the subsequent cucumber crop...

  11. Interactions of Meloidogyne incognita, Xanthomonas campestris, and Rhizobium sp. in the disease complex of chickpea

    SIDDIQUI, Zaki Anwar; FATIMA, Munavvar; ALAM, Subha

    2013-01-01

    The effects of Meloidogyne incognita, Xanthomonas campestris, and Rhizobium sp., alone or in combination, on the disease complex in chickpea were examined. Individual inoculation with M. incognita and X. campestris caused significant reductions in plant growth, while inoculation with Rhizobium sp. resulted in a significant increase in plant growth. Inoculation with M. incognita and X. campestris together caused a greater reduction in plant growth than the damage caused by each of them alone. ...

  12. Toxicidade de filtrados fúngicos a meloidogyne incognita

    COSTA MAURO J.N.

    2001-01-01

    Full Text Available Visando à obtenção de novas moléculas nematicidas, 18 filtrados de espécies fúngicas e extratos de sete micélios fúngicos foram estudados in vitro quanto aos efeitos sobre a eclosão, motilidade e mortalidade de juvenis do segundo estádio (J2 de Meloidogyne incognita. Filtrados fúngicos foram obtidos de culturas em meio Czapek. Metanol foi usado como solvente para obter extratos dos micélios fúngicos. Filtrados de Paecilomyces lilacinus, Fusarium moniliforme e Fusarium oxysporum reduziram a motilidade e eclosão, e aumentaram a mortalidade (P < 0,05 de J2 de M. incognita de forma semelhante à observada com Aldicarbe. Alguns filtrados fúngicos reduziram a motilidade, mas não causaram a morte de J2. Já os filtrados de Aspergillus flavus, Cylindrocarpon magnusianum, Fusarium solani e Mortierella sp. reduziram apenas a eclosão de J2. Não houve correlação entre a produção de metabólitos tóxicos e a quantidade de micélio fúngico produzido. No caso específico de P. lilacinus, observou-se que após o primeiro dia de cultivo o filtrado fúngico correspondente já apresentava toxidez contra M. incognita. Com o aumento do número de dias de cultivo foi elevado o efeito do filtrado sobre o nematóide, sendo que apenas após 13 dias a mortalidade de J2 alcançou o índice de 100%.

  13. Raphanus sativus, Sinapis alba, and Fagopyrum esculentum as Hosts to Meloidogyne incognita, Meloidogyne javanica, and Plasmodiophora brassicae

    Gardner, J.; Caswell-Chen, E.P.

    1994-01-01

    Cultivars of oilseed radish (Raphanus sativus var. oleifera cv. Adagio, Nemex, Pegletta, Renova, Siletina, Siletta Nova, and Ultimo), white mustard (Sinapis alba cv. Albatross, Emergo, Maxi, Martigena, Metex, and Serval), buckwheat (Fagopyrum esculentum cv. Prego, Tardo), and phacelia (Phacelia tanacetifolia cv. Angelia) were tested for susceptibility to Meloidogyne incognita race 3 and Meloidogyne javanica. Experiments were conducted in growth chambers at 25 C and 16 hours light for 42 days ...

  14. Effect of cowpea aphid-borne mosaic virus on penetration and reproduction of meloidogyne incognita in cowpea

    Adekunle O.K.; Owa T.E.

    2008-01-01

    greenhouse studies were conducted to investigate the effects of cowpea aphid-borne mosaic virus on penetration and reproduction of Meloidogyne incognita in cowpea and the influence of these pathogens on the yield of cowpea. The interaction of both pathogens resulted in higher population density of the nematode at harvest and correspondingly reduced grain yield in comparison to inoculation of either pathogen alone or un-inoculated control. An almost equal number of nematode juveniles penetrate...

  15. Evaluation of Pochonia chlamydosporia, Paecilomyces lilacinus and Arthrobotrys dactyloide as Biocontrol Agents for Meloidogyne incognita under Green House Condition

    Abd El-Raheem R. EL-Shanshoury

    2005-01-01

    Full Text Available In this study, evaluation of the nematophagous fungi Pochonia chlamydosporia, Paecilomyces lilacinus and Arthrobotrys dactyloide as biological control agents for Meloidogyne incognita was investigated under greenhouse conditions. Experiments confirmed the effectiveness of these predatory and parasitic fungi that actively reduced the number of infective larvae of M. incognita. The killing effect of these fungi is similar to the synthetic chemical nematicide Furadan and significantly better than the commercial preparation of bioagent Nameless?. The fungi under consideration have the potentiality to reduce population density of M. incognita along the growing season of faba bean plant to 95.4 to 98.9%. These nematophagous fungi enhanced shoot and root growth of Faba bean.

  16. Produtos naturais aplicados para manejo de Meloidogyne incognita em tomateiros

    Thiago Anchieta de Melo

    2012-09-01

    Full Text Available Este trabalho teve por objetivo avaliar o efeito de produtos naturais na expresso da resistncia a Meloidogyne incognita em plantas de tomate produzidos organicamente. Os indutores Rocksil, Quitosana, Neemseto e Biopirol foram aplicados 5, 10 e 15 dias, em tratamentos independentes, antes da inoculao do patgeno atravs da pulverizao foliar, utilizando-se duas dosagens para cada indutor. A inoculao do nematoide foi realizada 30 dias aps o plantio, usando-se 5000 ovos/ planta. Avaliando-se o nmero de ovos e o fator de reproduo, 30 dias aps a inoculao, observou-se que todos os tratamentos diferiram estatisticamente da testemunha, impedindo o aumento da populao inicial do patgeno. Dentre os indutores, o indutor silicatado Rocksil foi o que apresentou os melhores resultados para o controle da meloidoginose em todas as pocas de aplicao e em todas as dosagens. Contudo, plantas tratadas com o produto apresentaram baixos pesos de parte area sugerindo que houve um custo adaptativo de resistncia. Considerando-se o fator de reproduo no foram observadas diferenas estatsticas quando comparadas a dosagem e poca de aplicao entre os indutores, com exceo da Quitosana aplicada aos 5 dias antes da inoculao e do Neemseto aplicado aos 15 dias antes da inoculao do nematide.

  17. Comportamiento de Meloidogyne incognita sobre tomate y pimiento resistente en Uruguay

    Piedra Buena, A.; Dez-Rojo, M. A.; Bello Prez, Antonio; Robertson, Lee; Lpez-Prez, J. A.; Escuer, M.; Len, L.

    2005-01-01

    [ES] Para evaluar la influencia del sistema de cultivo en la seleccin de biotipos virulentos de Meloidogyne incognita en Uruguay, se estudi la virulencia de 33 poblaciones de este nematodo procedentes de invernaderos, tanto en monocultivo como en rotacin, mediante bioensayos con cultivares de tomate y pimiento resistentes a M. incognita. Se encontraron 36,4% de las poblaciones virulentas a tomate y pimiento resistentes; 33,3% virulentas a tomate resistente, pero ...

  18. Meloidogyne incognita Survival in Soil Infested with Paecilomyces lilacinus and Verticillium chlamydosporium

    Gaspard, J.T.; Jaffee, B.A.; Ferris, H.

    1990-01-01

    Meloidogyne incognita-infected tomato seedlings were transplanted into sterilized soil or unsterilized soil collected from 20 California tomato fields to measure suppression caused by Paecilomyces lilacinus, Verticillium chlamydosporium, and other naturally occurring antagonists. Unsterilized soils Q, A, and H contained 35, 39, and 55% fewer M. incognita second-stage juveniles (J2) than did sterilized soil 1 month after infected tomato seedlings were transplanted to these soils and placed in ...

  19. Response of Cowpea Breeding Lines and Cultivars to Meloidogyne incognita and M. arenaria

    Kirkpatrick, T L; Moreflock, T. E.

    1987-01-01

    Twenty-four cowpea breeding lines and four cultivars were tested for resistance to Meloidogyne incognita in the greenhouse. Gall and egg mass ratings indicated a range of responses from susceptible to highly resistant. Five breeding lines - VS84-2, VS84-8, VS84-12, VS84-14, and VS84-22 - and the cultivar Erectset had gall and egg mass ratings comparable to the M. incognita-resistant cultivar Mississippi Silver. All of these were also resistant to M. arenaria. Significantly fewer M. incognita ...

  20. Protease inhibition by Heterodera glycines cyst content: evidence for effects on the Meloidogyne incognita proteasome

    Proteases from Heterodera glycines and Meloidogyne incognita juveniles were inhibited by heat-stable content of H. glycines female cysts (HglCE), and by the plant polyphenol epigallocatechin gallate (EGCG). General protease activities detected using the nematode peptide KSAYMRFa were inhibited by EG...

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

    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.

  2. Susceptibility of Several Common Subtropical Weeds to Meloidogyne arenaria, M. incognita, and M. javanica.

    Kokalis-Burelle, Nancy; Rosskopf, Erin N

    2012-06-01

    Experiments were conducted in the greenhouse to assess root galling and egg production of three root-knot nematode species, Meloidogyne arenaria, M. incognita, and M. javanica, on several weeds common to Florida agricultural land. Weeds evaluated were Amaranthus retroflexus (redroot pigweed), Cyperus esculentus (yellow nutsedge), Eleusine indica (goosegrass), Portulaca oleracea (common purslane), and Solanum americanum (American black nightshade). Additionally, although it is recommended as a cover crop in southern regions of the U.S., Aeschynomene americana (American jointvetch) was evaluated as a weed following the detection of root galling in a heavy volunteer infestation of an experimental field in southeastern Florida. Weeds were propagated from seed and inoculated with 1000 nematode eggs when plants reached the two true-leaf stage. Tomato (Solanum lycopersicum 'Rutgers') was included as a positive control. Aeschynomene americana and P. oleracea roots supported the highest number of juveniles (J2) and had the highest number of eggs/g of root for all three species of Meloidogyne tested. However, though P. oleracea supported very high root levels of the three nematode species tested, its fleshy roots did not exhibit severe gall symptoms. Low levels of apparent galling, combined with high egg production, increase the potential for P. oleracea to support populations of these three species of root-knot nematodes to a degree that may not be appropriately recognized. This research quantifies the impact of P. oleracea as a host for M. arenaria, M. incognita, and M. javanica compared to several other important weeds commonly found in Florida agricultural production, and the potential for A. americana to serve as an important weed host of the three species of root-knot nematode tested in southern regions of Florida. PMID:23482324

  3. Seed treatment affects Meloidogyne incognita penetration, colonization and reproduction on cotton / Tratamento de sementes afeta a penetrao, colonizao e reproduo de Meloidogyne incognita em algodo

    Rosana, Bessi; Fernando Ribeiro, Sujimoto; Mrio Massayuki, Inomoto.

    2010-06-01

    Full Text Available O efeito de abamectina em tratamento de sementes na penetrao, colonizao e reproduo de Meloidogyne incognita, em algodo, foi avaliado em dois experimentos de casa de vegetao. A penetrao de juvenis de segundo estdio (J2) foi avaliada aos trs, nove e 15 dias aps a germinao (dag), enquan [...] to que a colonizao 27dag foi avaliada por meio da contagem do nmero total de galhas e massas de ovos por sistema radicular. Ovos e J2 de M. incognita foram extrados das razes para determinar a reproduo do nematoide aos 50 e 100dag. O tratamento de sementes diminuiu a penetrao dos J2 nas razes, resultando em menor colonizao e reproduo de M. incognita. Os resultados obtidos so discutidos tendo em vista os aspectos ambientais da presena de abamectina no solo e as prticas agrcolas em uso. Abstract in english The effect of abamectin, applied as seed treatment, on Meloidogyne incognita penetration, colonization, and reproduction on cotton was evaluated in two greenhouse experiments. Second stage juveniles (J2) penetration was evaluated 3, 9 and 15 days after germination (dag), whereas the nematode coloniz [...] ation was evaluated 27dag, by counting the total number of galls and egg masses per root system. Eggs and J2 were extracted from the roots to assess the nematode reproduction at 50 and 100dag. The seed treatment caused a decrease in J2 penetration in the roots, resulting in lower colonization and reproduction of M. incognita. These findings are discussed considering the environmental aspects of abamectin in the soil and the current practices for the crop management.

  4. Seed treatment affects Meloidogyne incognita penetration, colonization and reproduction on cotton Tratamento de sementes afeta a penetrao, colonizao e reproduo de Meloidogyne incognita em algodo

    Rosana Bessi

    2010-06-01

    Full Text Available The effect of abamectin, applied as seed treatment, on Meloidogyne incognita penetration, colonization, and reproduction on cotton was evaluated in two greenhouse experiments. Second stage juveniles (J2 penetration was evaluated 3, 9 and 15 days after germination (dag, whereas the nematode colonization was evaluated 27dag, by counting the total number of galls and egg masses per root system. Eggs and J2 were extracted from the roots to assess the nematode reproduction at 50 and 100dag. The seed treatment caused a decrease in J2 penetration in the roots, resulting in lower colonization and reproduction of M. incognita. These findings are discussed considering the environmental aspects of abamectin in the soil and the current practices for the crop management.O efeito de abamectina em tratamento de sementes na penetrao, colonizao e reproduo de Meloidogyne incognita, em algodo, foi avaliado em dois experimentos de casa de vegetao. A penetrao de juvenis de segundo estdio (J2 foi avaliada aos trs, nove e 15 dias aps a germinao (dag, enquanto que a colonizao 27dag foi avaliada por meio da contagem do nmero total de galhas e massas de ovos por sistema radicular. Ovos e J2 de M. incognita foram extrados das razes para determinar a reproduo do nematoide aos 50 e 100dag. O tratamento de sementes diminuiu a penetrao dos J2 nas razes, resultando em menor colonizao e reproduo de M. incognita. Os resultados obtidos so discutidos tendo em vista os aspectos ambientais da presena de abamectina no solo e as prticas agrcolas em uso.

  5. HISTOPATHOLOGICAL CHANGES AND ENZYMATIC ACTIVITIES INDUCED BY MELOIDOGYNE INCOGNITA ON RESISTANT AND SUSCEPTIBLE POTATO

    Moawad M. Mohamad

    2012-12-01

    Full Text Available All potato cultivars are susceptible to root-knot nematodes (Meloidogyne spp. which infest the roots and induce galls on the surface and necrotic spots in the flesh tuber of potato, Solanum tuberosum. Infested tubers are unacceptable for processing and fresh market. Tubers are also putative source of dissemination of the nematode. A French nematode- resistant tetraploid potato genotype gained from ex-S. sparsipilum material hybridized with S. tuberosum in F1 and in their back cross progenies and designated as 02T.155.6 was tested and compared in the present study in Egypt as a suitable different environment. Histopathological changes and chitinase activity induced by M. incognita population, of common occurrence in Egypt, in four French tetraploid materials and two common cultivars known as nematode- resistant and susceptible potato genotypes were investigated. Hypertrophied cells were initiated in both cortical and steler regions of the roots which were then developed to abnormal xylem elements expanding into the cortex in French susceptible genotypes designated as 02T.149.6, 02T.150.54, and 02T.157.16. Nematode within the vascular tissue (stele could induce giant cell development close to nematode heads. The largest number of such induced cells was shown by the cultivars Spunta and Diamant. The clone 02T.155.6 with putative nematode resistance demonstrated none or very little nematode development. Recently dead second stage juveniles could also indicate incompatible plant reaction to the invading nematodes in 02T.155.6. M. incognita, Giza population, resistance was generally more coherent to 02T.155.6 as demonstrated by our histological investigations but less coherent as shown by another Egyptian M. incognita population. Chitinase activity was enhanced in M. incognita (Giza-inoculated with respect to uninoculated roots in all plants. After inoculation, such an activity generally increased more in roots of a potato genotype previously known to have resistance or relatively low numbers of both nematode galls and eggmasses than in the other tested cultivars. Peroxidase and catalase activities of nematode- inoculated with respect to uninoculated potato roots were presented and discussed.

  6. Effects of Soil Compaction and Meloidogyne incognita on Cotton Root Architecture and Plant Growth.

    Ma, Jianbing; Kirkpatrick, Terrence L; Rothrock, Craig S; Brye, Kristofor

    2013-06-01

    The effects of a soil hardpan and Meloidogyne incognita on cotton root architecture and plant growth were evaluated in microplots in 2010 and 2011. Soil was infested with M. incognita at four different levels with or without a hardpan. The presence of a hardpan resulted in increased plant height, number of main stem nodes, and root fresh weight for cotton seedlings both years. Meloidogyne incognita decreased height and number of nodes for seedlings in 2010. Nematode infestation increased seedling root length and enhanced root magnitude, altitude, and exterior path length in 2010. This was also the case for root length and magnitude in 2011 at lower infestation levels suggesting compensatory growth. A hardpan had no consistent effect on these root parameters but increased root volume in both years. A hardpan hastened crop maturity and increased the number of fruiting branches that were produced, while M. incognita infection delayed crop development and reduced plant height and number of bolls. Both M. incognita infection and a hardpan reduced taproot length and root dry weight below the hardpan in both years. Root topological indices under all the treatments ranged from 1.71 to 1.83 both years indicating that root branching followed a herringbone pattern. The techniques for characterizing root architecture that were used in this study provide a greater understanding of changes that result from disease and soil abiotic parameters affecting root function and crop productivity. PMID:23833326

  7. Influence of low temperature on development of Meloidogyne incognita and M. hapla eggs in egg masses.

    Vrain, T C; Barker, K R

    1978-10-01

    Egg masses of Meloidogyne incognita and M. hapla were placed in soil at 10, 12, 16, and 20 C. At regular intervals, eggs from samples of egg masses were released from the gelatinous matrices and their developmental stages recorded. The number of days necessary to complete each stage from gastrulation to hatch is given for each temperature. The minimal temperature threshold for the development of eggs was computed by linear regression to be 8.26 C for M. incognita and 6.74 C for M. hapla. PMID:19305859

  8. Mustard seed meal mixtures: management of Meloidogyne incognita on pepper and potential phytotoxicity

    Meyer, Susan l. F.; ZASADA, INGA A; Orisajo, Samuel B.; Morra, Matthew J.

    2011-01-01

    Meals produced when oil is extracted from seeds in the Brassicaceae have been shown to suppress weeds and soilborne pathogens. These seed meals are commonly used individually as soil amendments; the goal of this research was to evaluate seed meal mixes of Brassica juncea (Bj) and Sinapis alba (Sa) against Meloidogyne incognita. Seed meals from Bj ‘Pacific Gold’ and Sa ‘IdaGold’ were tested alone and in combinations to determine rates and application times that would suppress M. incognita on p...

  9. Mustard seed meal mixtures: management of Meloidogyne incognita on pepper and potential phytotoxicity.

    Meyer, Susan L F; Zasada, Inga A; Orisajo, Samuel B; Morra, Matthew J

    2011-03-01

    Meals produced when oil is extracted from seeds in the Brassicaceae have been shown to suppress weeds and soilborne pathogens. These seed meals are commonly used individually as soil amendments; the goal of this research was to evaluate seed meal mixes of Brassica juncea (Bj) and Sinapis alba (Sa) against Meloidogyne incognita. Seed meals from Bj 'Pacific Gold' and Sa 'IdaGold' were tested alone and in combinations to determine rates and application times that would suppress M. incognita on pepper (Capsicum annuum) without phytotoxicity. Rates of soil application (% w/w) for the phytotoxicity study were: 0.5 Sa, 0.2 Bj, 0.25 Sa + 0.25 Bj, 0.375 Sa + 0.125 Bj, 0.125 Sa + 0.375 Bj, and 0, applied 0 - 5 weeks before transplant. Overall, 0.2% Bj was the least toxic meal to pepper seedlings. By comparison, 0.5% S. alba seed meal did not reduce lettuce (Lactuca sativa) seed germination at week 0, but all seed meal treatments containing B. juncea prevented or significantly reduced germination at week 0. The seed meals did not affect lettuce seed germination at weeks 1-5, but hypocotyl growth was reduced by all except 0.2% Bj at weeks 1, 4 and 5. Brassica juncea and Sa meals were tested for M. incognita suppression at 0.2, 0.15, 0.1 and 0.05%; mixtures were 0.1% Sa + 0.1% Bj, 0.15% Sa + 0.05% Bj, and 0.05% Sa + 0.15% Bj. All treatments were applied 2 weeks before transplant. The 0.2% Bj and 0.05% Sa + 0.15% Bj treatments overall had the longest shoots and highest fresh weights. Eggs per g root were lowest with 0.1 - 0.2% Bj amendments and the seed meal mixtures. The results indicate that Bj and some Bj + Sa mixtures can be applied close to transplant to suppress M. incognita populations on pepper; consequently, a seed meal mixture could be selected to provide activity against more than one pest or pathogen. For pepper, care should be taken in formulating mixtures so that Sa rates are low compared to Bj. PMID:22791910

  10. Adaptação hospedeira de variedades de abacaxi a meloidogyne incognita raça 1 Host suitability of pineapple varieties for meloidogyne incognita race 1

    Leila Lucí Dinardo-Miranda; Ademar Spironello; Antonio Lúcio de Mello Martins

    1996-01-01

    Avaliou-se, em campo naturalmente infestado, a adaptação hospedeira das variedades de abacaxi Smooth Cayenne, Abacaxi-de-gomo, Bico-de-rosa, Boituva, Guiana, Huitota, Manzana, Natal Queen, Pérola, Perolera, Rondon, Roxo-de-Tefé e Turi Verde a Meloidogyne incognita raça 1. Somente 'Huitota' apresentou populações do nematóide significativamente menores que aquelas encontradas na 'Smooth Cayenne', considerada boa hospedeira da espécie.The host suitability of thirteen pineapple varieties, namely ...

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

    Tedford, E. C.; Fortnum, B. A.

    1988-01-01

    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 < 0.05) among weed species. Chenopodium album, Euphorbia maculata, and Vicia villosa were good hosts of M. arenaria. Amaranthus palmeri, Rumex crispus, Amaranthus hybridus, Ambrosia artemisiifolia, lpomoea hederacea var. integriuscula, Setaria lutescens, Sida spinosa, Portulaca...

  12. Intensity and duration of water deficit on the pathosystem sugarcane x Meloidogyne incognita / Intensidade e durao do dficit hdrico no patossistema cana-de-acar x Meloidogyne incognita

    Matheus P., Quintela; Elvira M. R., Pedrosa; Lilia, Willadino; Mario M., Rolim; nio F. de F. e, Silva; Mariana F. de L., David.

    2015-06-01

    Full Text Available RESUMO Neste trabalho objetivou-se estudar a interao entre a intensidade e a durao do dficit hdrico (90, 56 e 22% capacidade de pote [CP] por 30, 60 e 90 dias de estresse contnuo) associado ao parasitismo do nematoide Meloidogyne incognita no crescimento inicial da cana-de-acar variedade RB [...] 92579 e atividade das enzimas catalase e ascorbato peroxidase. O delineamento adotado foi inteiramente casualizado em esquema fatorial 7 (tratamentos hdricos: controle [90% da CP], 56% CP com durao de 30, 60 e 90 dias, 22% CP com durao de 30, 60 e 90 dias) 2 (densidade de M. incognita: 0 e 20000 ovos por planta), com quatro repeties. O estresse hdrico correspondente a 56% da CP com durao de 30 e 60 dias no afetou o desenvolvimento da variedade RB92579. Os tratamentos hdricos testados aumentaram a atividade da enzima ascorbato peroxidase, porm no afetaram a atividade da enzima catalase. O nematoide no afetou as respostas da RB92579 nas condies estudadas; enfim, o dficit hdrico com maior severidade (22% CP por 90 dias) reduziu a reproduo do M. incognita. Abstract in english ABSTRACT This study aimed to evaluate the interaction between intensity and duration of water deficit (90, 56 and 22% of pot capacity [PC] for 30, 60 and 90 days under continuous stress) associated to the parasitism of the nematode Meloidogyne incognita on the growth of the sugarcane variety RB92579 [...] and the activity of the enzymes catalase and ascorbate peroxidase. The experiment was conducted in completely randomized design in a 7 x 2 factorial scheme (seven water deficit treatments: control [90% PC], 56% PC for 30, 60 and 90 days, 20% PC for 30, 60 and 90 days; and two densities of M. incognita: 0 and 20000 eggs plant-1), with four replicates. The water stress corresponding to 56% PC for 30 or 60 days did not affect RB92579 development. The evaluated water treatments increased ascorbate peroxidase activity, but it did not affect catalase activity. Nematode inoculation did not affect RB92579 responses to drought stress conditions. The higher severity of water deficit (22% PC for 90 days) reduced M. incognita reproduction.

  13. Histopathological Response of Lens culinaris Roots Towards Root-knot Nematode, Meloidogyne incognita

    Hisamuddin

    2013-01-01

    Full Text Available Lens culinaris (lentil is an important pulse crop. The yield of the crop is reduced if grown in root-knot nematode (Meloidogyne incognita infested field. Meloidogyne incognita caused infection in primary and the secondary roots leading to the anomalies in the affected part of the root. The study revealed that the second stage juveniles (J2 of Meloidogyne incognita entered the growing roots and their branches inter and intracellularly. The immediate response was hypertrophy and hyperplasia in the root tissue near the nematode head. In response to hypertrophy some cells became very large and contained dense and granular cytoplasm. Adjacent to the giant cells, the vascular tissue was found to be disturbed. Shape, size and orientation of the vascular elements was so much altered that it had become difficult to trace the normal course of vascular strands. In various sections vascular strands were found disrupted. The vessel elements had the shapes resembling the shapes of parenchyma cells. Similarly sieve tube elements of the phloem, near the giant cells were shorter and resembled with nearby parenchyma cells. Abnormalities in xylem and phloem favored transport water, minerals and metabolites towards the giant cells. From this study, it might be inferred that alteration in the cells of galled tissue was essential for the sustenance of giant cells and for the survival of the nematode.

  14. EFFECT OF ROOT EXUDATES OF TAGETES SP. ON EGG HATCHING BEHAVIOR OF MELOIDOGYNE INCOGNITA

    Iruthaya Kalaiselvam

    2011-10-01

    Full Text Available The effect root exudates of pre-planted marigold intercropped with tomato in regulating the hatching behavior of root-knot nematode - Meloidogyne incognita eggs were investigated. Marigold cultivars Tagetes patula, T. minuta, T. erecta, T. erecta (var. Orange, T. erecta (var. Yellow significantly reduced the numbers of second-stage juveniles (J2s in subsequent tomato compared to the tomato-tomato control. Four different concentrations (25, 50, 75 and 100 % of water soluble extract from the selected varieties of Marigold cultivars were filtered and added to the petri dish and infested with the eggs of M. incognita. Data indicate that egg hatching was significantly affected by root exudates of Tagetes sp. however, nematicidal activity was species dependent. Root exudates of T. erecta were lethal to J2 of M. incognita and were inhibitory to the hatch of eggs at the concentration of 75 % or higher.

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

    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 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. PMID:19290313

  16. The nematicidal effect of some bacterial biofertilizers on Meloidogyne incognita in sandy soil

    M.E El-Hadad

    2011-03-01

    Full Text Available In a greenhouse experiment, the nematicidal effect of some bacterial biofertilizers including the nitrogen fixing bacteria (NFB Paenibacillus polymyxa (four strains, the phosphate solubilizing bacteria (PSB Bacillus megaterium (three strains and the potassium solubilizing bacteria (KSB B. circulans (three strains were evaluated individually on tomato plants infested with the root-knot nematode Meloidogyne incognita in potted sandy soil. Comparing with the uninoculated nematode-infested control, the inoculation with P. polymyxa NFB7, B. megaterium PSB2 and B. circulans KSB2, increased the counts of total bacteria and total bacterial spores in plants potted soil from 1.2 to 2.6 folds estimated 60 days post-inoculation. Consequently, the inoculation with P. polymyxa NFB7 increased significantly the shoot length (cm, number of leaves / plant, shoot dry weight (g / plant and root dry weight (g / plant by 32.6 %, 30.8 %, 70.3 % and 14.2 %, respectively. Generally, the majority treatments significantly reduced the nematode multiplication which was more obvious after 60 days of inoculation. Among the applied strains, P. polymyxa NFB7, B. megaterium PSB2 and B. circulans KSB2 inoculations resulted in the highest reduction in nematode population comparing with the uninoculated nematode-infested control. They recorded the highest reduction in numbers of hatched juveniles/root by 95.8 %, females/root by 63.75 % and juveniles/1kg soil by 57.8 %. These results indicated that these bacterial biofertilizers are promising double purpose microorganisms for mobilizing of soil nutrients (nitrogen, phosphate and potassium and for the biological control of M. incognita.

  17. Interactions between arbuscular mycorrhizal fungi and Meloidogyne incognita in the ornamental plant Impatiens balsamina

    J, Banuelos; A, Alarcn; J, Larsen; S, Cruz-Snchez; D, Trejo.

    2014-03-01

    Full Text Available Biocontrol traits of arbuscular mycorrhizal fungi (AMF), in terms of single and mixed species inoculum, against the root knot nematode Meloidogyne incongita in Impatiens balsamina L., were examined with and without mineral fertilization in a greenhouse pot experiment. At harvest, 60 days after sowin [...] g, general plant growth parameters and plant defense response in terms of antioxidant activity and content of phenolic compounds in roots and leaves were measured. Also AMF root colonization and abundance ofnematode root-knots were determined. Mineral fertilization increased all plant growth parameters measured, which coincided with an increased disease development caused by M. incognita. Inoculation with AMF mitigated the observed plant growth reduction caused by M.incognita, though, higher abundance of M. incognita root knots was found in mycorrhizal plants. Plant defense responses in terms of antioxidant activity and content of phenolic compounds did not seem to be linked to the observed biocontrol traits of AMF against M. incognita. However, roots inoculated with a consortium of AMF, which presented less nematode root knots than roots with the single species inoculum, had the highest level of phenolic compounds. The results from the present study suggest that AMF induce tolerance in I. balsamina against the root knot nematode M. incognita.

  18. Meloidogyne incognita Inoculum Source Affects Host Suitability and Growth of Yellow Nutsedge and Chile Pepper.

    Thomas, S H; Schroeder, J; Kenney, M J; Murray, L W

    1997-09-01

    Meloidogyne incognita (Mi) reproduction and host plant responses in chile pepper (Capsicum annuum) and yellow nutsedge (Cyperus esculentus = YNS) to three sources of inoculum obtained by rearing a single Mi population on chile, YNS, and tomato were evaluated in two factorial greenhouse experiments. The interactive effects of Mi inoculum source and crop-weed competition were determined. In the absence of YNS competition, chile growth was reduced less by Mi inoculum from chile than by inoculum from YNS or tomato. When YNS was present, chile root weight was not affected and shoot weight increased with Mi initial inoculation, regardless of inoculum source. Chile plants inoculated with Mi from tomato exhibited double the nematode reproduction observed with inoculum from chile or YNS. With chile present, Mi reproduction on YNS was nearly three times greater with inoculum from tomato, but reproduction was similar among inoculum sources when chile was absent. Reductions in YNS root mass due to competition from chile failed to reduce the total number of Mi eggs produced on YNS plants. Differences in total Mi reproduction among inoculum sources were not attributable to differences in root growth or plant competition. This study illustrates the influence of Mi-YNS interactions and previous hosts on severity of Mi infection. PMID:19274174

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

    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.

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

    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.

  1. Efeitos do nível de inóculo de Meloidogyne incognita em algodoeiro Effects of low inoculum level of Meloidogyne incognita on cotton plants

    MARLUCI MUNDIN ABRÃO; PAULO MAZZAFERA

    2001-01-01

    Pesquisas acerca da fisiologia de plantas em resposta ao ataque de nematóides normalmente são feitas com doses altas de inóculo, quer sejam ovos ou juvenis de segundo estágio. Diferentemente, as avaliações da resistência de plantas a nematóides em programas de melhoramento são realizadas com doses bastante inferiores. Neste estudo acompanhou-se a variação de alguns parâmetros fisiológicos em algodão, em resposta à aplicação de baixas doses de inóculo de Meloidogyne incognita raça 3. Duas cult...

  2. Patogenicidade de Meloidogyne exigua e M. incognita raça 1 a mudas de cafeeiros Pathogenicity of Meloidogyne exigua and M. incognita race 1 to coffee seedlings

    Wallace Gonçalves; Luiz Carlos Camargo Barbosa Ferraz; Marinez Muraro Alues de Lima; Maria Bernadete Silvarolla

    1996-01-01

    O presente trabalho teve por objetivo avaliar os danos causados por Meloidogyne exigua e M. incognita raça 1 a mudas de cafeeiros (Coffea spp.) Coffea arabica cv. Mundo Novo (LCP 515-20) e de C. canephora cv. Robusta (C 2258). O ensaio foi desenvolvido em casa de vegetação, em vasos de um litro, contendo uma plântula cada um. Aos vinte dias após o transplante, as plântulas foram inoculadas separadamente com 0, 2.000, 4.000 e 8.000 ovos de cada nemat��ide. As populações dos parasitos nas raíze...

  3. In vitro toxicity and control of Meloidogyne incognita in soybean by rosemary extract

    Mônica Anghinoni Müller

    2016-02-01

    Full Text Available The control of nematodes in plants can be challenging, and there is a need for alternative, environmentally conscious methods for their management. The purpose of this study was to evaluate the effect of rosemary extract (Rosmarinus officinalis on the in vitro toxicity and control of Meloidogyne incognita in CD 206 and CD 215 soybean cultivars. Using an in vitro assay, 500 M. incognita eggs per plate were observed for 15 days after incubation with rosemary extract at concentrations of 1%, 5%, and 10%. Soybean plants were studied under greenhouse conditions, and starting at V3 stage, were sprayed weekly with the same concentration of rosemary extract for 64 days. Three days after the first treatment, each soybean plant was inoculated with 1800 eggs and 400 second-stage juveniles (J2. At the end of this essay, number of eggs and J2 in the roots and soil, number of galls, and the reproduction factor (RF were evaluated. Our results showed that in the in vitro assay, rosemary extract reduced the number of M. incognita eggs that hatched. Under greenhouse conditions, the CD 206 cultivar showed a 48% reduction in the number of galls, as well as fewer eggs in the soil and a lower RF. Similarly, in the CD 215 cultivar, the number of eggs was reduced and the RF was lower. These results indicate the potential for rosemary extract to control M. incognita in soybean crops.

  4. Pepper Rootstock Graft Compatibility and Response to Meloidogyne javanica and M. incognita.

    Oka, Yuji; Offenbach, Rivka; Pivonia, Shimon

    2004-06-01

    Resistance of pepper species (Capsicum annuum, C. baccatum, C. chinense, C. chacoense, and C. frutescens), cultivars and accessions to the root-knot nematodes Meloidogyne incognita race 2 and M. javanica, and their graft compatibility with commercial pepper varieties as rootstocks were evaluated in growth chamber and greenhouse experiments. Most of the plants tested were highly resistant to M. javanica but susceptible to M. incognita. Capsicum annuum AR-96023 and C. frutescens accessions as rootstocks showed moderate and relatively high resistance to M. incognita, respectively. In M. incognita-infested soil in a greenhouse, AR-96023 supported approximately 6-fold less nematode eggs per gram root and produced about 2-fold greater yield compared to a nongrafted commercial variety. The commercial variety grafted on AR-96023 produced a yield as great as the non-grafted variety in the root-knot nematode-free greenhouse. Some resistant varieties and accessions used as rootstocks produced lower yields (P < 0.01) than that of the non-grafted variety in the noninfested greenhouse. Use of rootstocks with nematode-resistance and graft compatibility may be effective for control of root-knot nematodes on susceptible pepper. PMID:19262798

  5. Influence of low temperature on rate of development of Meloidogyne incognita and M. hapla larvae.

    Vrain, T C; Barker, K R; Holtzman, G I

    1978-04-01

    Development of Meloidogyne incognita and M. hapla larvae in clover roots was studied at 20, 16, 12, and 8 C in growth chambers and in the field from fall through spring, in North Carolina. Larvae of both species invaded roots and developed at 20, 16, and 12 C, but not at 8 C. The time necessary to complete the larval stages at each temperature was determined. The minimal temperature for development of M. incognita larvae was 10.08 C and 8.8 C for M. hapla larvae. In the field, soil temperature at 10 cm deep was favorable for development of larvae until the end of November, and again from February on. All stages of the nematodes survived freezing temperatures in the roots. Reproduction of both species was evident in March or Apri1 after inoculation and accumulation of 8,500 to 11,250 degree-hours. PMID:19305832

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

    Jorge Augusto Assis Gomes; Valter Carvalho Andrade Júnior; Celso Mattes Oliveira; Alcinei Mistico Azevedo; Wilson Roberto Maluf; Luiz Antonio Augusto Gomes

    2015-01-01

    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. S...

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

    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...

  8. Effect of cowpea aphid-borne mosaic virus on penetration and reproduction of meloidogyne incognita in cowpea

    Adekunle O.K.

    2008-01-01

    Full Text Available greenhouse studies were conducted to investigate the effects of cowpea aphid-borne mosaic virus on penetration and reproduction of Meloidogyne incognita in cowpea and the influence of these pathogens on the yield of cowpea. The interaction of both pathogens resulted in higher population density of the nematode at harvest and correspondingly reduced grain yield in comparison to inoculation of either pathogen alone or un-inoculated control. An almost equal number of nematode juveniles penetrated roots of seedlings of nematode - susceptible Ife Brown and TVU 2657 and nematode - resistant IT81D - 975 cultivars of cowpea, but the nematode did not develop beyond second stage juvenile in the resistant cultivar. Concomitant inoculation of the nematode and the virus resulted in a shortened life cycle of the nematode in comparison to nematode alone inoculation. Interaction of both the nematode and the virus had a limited effect on the nematode resistant cultivar of cowpea.

  9. Direct Identification of the Meloidogyne incognita Secretome Reveals Proteins with Host Cell Reprogramming Potential

    Bellafiore, Stéphane; Shen, Zhouxin; Rosso, Marie-Noelle; Abad, Pierre; Shih, Patrick; Briggs, Steven P.

    2008-01-01

    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 conservation of function between metazoan parasites of plants and animals. PMID:18974830

  10. Efectividad de hongos nematfagos sobre Meloidogyne incognita (Kofoid y White) Chitwood en tomate en condiciones de campo, Loja, Ecuador / Effectiveness of nematophagous fungi on Meloidogyne incognita (Kofoid and White) Chitwood on tomato in field conditions in Loja, Ecuador

    Tulio F., Solano Castillo; Marcia L., Castillo vila; Jos V., Medina Medina; Elio M., del Pozo Nez.

    2014-12-01

    Full Text Available El objetivo del presente trabajo fue determinar el efecto de varios aislamientos autctonos de los hongos Pochonia chlamydosporia (Goddard) Zare y Gams (Hypocreales: Clavicipitaceae) y Purpureocillium lilacinum Luansa-ard et al. (Hypocreales: Ophiocordycipitaceae) en el control de Meloidogyne incogn [...] ita (Kofoid y White) Chitwood, en tomate, en condiciones de campo. Se utilizaron seis aislamientos fngicos y un control sin aplicacin, distribuidos segn un diseo de bloques al azar con cuatro rplicas. Las aplicaciones de los hongos lograron reducir el ndice de agallamiento por M. incognita, as como las poblaciones de juveniles infestivos (J2) en el suelo y en las races del cultivo, a la vez que se observ un estmulo en las variables agronmicas nmero de frutos, masa de los frutos y rendimiento agrcola. Estos resultados constituyen una contribucin a la solucin del problema de los nematodos formadores de agalla, en el cultivo del tomate en las condiciones de Loja, Ecuador, con recursos locales, no agresivos al medio ambiente. Abstract in english This work was aimed to evaluate the effect of isolates of the fungi Pochonia chlamydosporia (Goddard) Zare and Gams (Hypocreales: Clavicipitaceae) and Purpureocillium lilacinum Luansa-ard et al. (Hypocreales: Ophiocordycipitaceae) in the Meloidogyne incognita (Kofoid and White) Chitwood control in t [...] omato in field conditions. The assay comprised six fungic isolates and a control without fungi, in a ramdomized block design. In treated plants the gall index and the nematode population in roots and in the soil were reduced in comparison with the untreated plots. The number of fruits, the weight of fruits and yields were enhanced in the plots treated with the fungi. These results are a contribution to the solution of the root-knot nematode problem in the conditions of Loja, Ecuador, with local resources and no harmful to the environment.

  11. Repulsion of Meloidogyne incognita by Alginate Pellets Containing Hyphae of Monacrosporium cionopagum, M. ellipsosporum, or Hirsutella rhossiliensis

    Robinson, A.F.; Jaffee, B.A.

    1996-01-01

    The responses of second-stage juveniles (J2) of Meloidogyne incognita race 3 to calcium alginate pellets containing hyphae of the nematophagous fungi Monacrosporiura cionopagum, M. ellipsosporum, and Hirsutella rhossiliensis were examined using cylinders (38-mm-diam., 40 or 72 mm long) of sand (94%

  12. SSR markers for marker assisted selection of root-knot nematode (Meloidogyne incognita) resistant plants in cotton (Gossypium hirsutum L.)

    Cotton (Gossypium hirsutum L) cultivars highly resistant to the southern root-knot nematode (RKN) [Meloidogyne incognita (Kofoid & White) Chitwood] are not available. Recently, molecular markers on chromosomes 11 and 14 have been associated with RKN resistance, thus opening the way for marker assis...

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

    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.

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

    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. PMID:22769561

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

    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.

  16. Screening of cucurbitaceous rootstocks and cucumber scions for root knot nematode resistance (Meloidogyne incognita Kofoid and White

    Punithaveni, V, P. Jansirani and M. Sivakumar

    2015-06-01

    Full Text Available A study was carried out under glasshouse condition at the Department of Nematology, Tamil Nadu Agricultural University, Coimbatore during 2012-2013 to identify resistant rootstocks of cucurbitaceous species for grafting of cucumber against root knot nematode, Meloidogyne incognita. Seven wild and cultivated cucurbitaceous rootstocks and two cucumber scions (variety and hybrid were used for screening studies against the root knot nematode. Forty fifth day after inoculation, the plants were evaluated for shoot length, root length, shoot fresh and dry weight as well as root fresh and dry weight, number of galls per 10 gram of root, egg mass and females per gram of root, root knot index, soil nematode population per 200 cc of soil and reproduction factor. The lowest number of galls and egg masses were observed in Citrullus colocynthis followed by Cucumis metuliferus which exhibited resistant reaction with root knot index (RKI of 2. The other rootstocks viz., Cucurbita ficifolia, Cucurbita moschata, C. maxima and Luffa cylindrica were found to be moderately resistant to root knot nematode with root knot index of 3. The two cucumber scions (Green Long variety and NS 408 hybrid were observed to be highly susceptible to M. incognita with RKI of 5.

  17. Influence of infection of cotton by Rotylenchulus Reniformis and Meloidogyne Incognita on the production of enzymes involved in systemic acquired resistance.

    Systemic acquired resistance (SAR), which results in enhanced defense mechanisms in plants, can be elicited by virulent and avirulent strains of pathogens including nematodes. Recent studies of nematode reproduction strongly suggest that Meloidogyne incognita and Rotylenchulus reniformis induce SAR ...

  18. Histopathological Studies of Eggplant Roots as Affected by IAA, Agrobacterium tumefaciens and Meloidogyne incognita Alone and in Combinations

    Mohamed A. Elwakil

    2003-01-01

    Full Text Available The anatomy of eggplant roots as affected by the application of IAA, Agrobacterium tumefaciens and Meloidogyne incognita alone and in combination was studied. IAA and A. tumefaciens, alone and in combination increased the root diameter, cortex thickness, number of cortex layers, stele diameter, number of xylem vessels but decreased the vessel diameter. Inoculation with M. incognita led to the formation of multinucleated giant cells surrounded by deformed xylem elements, hypertrophy of the cortex and hyperplasia of the pericycle. More giant cells with higher dimensions were formed and more eggs/egg mass were produced in plants where IAA, A. tumefaciens alone or in combination was introduced with M. incognita. On the other hand, the presence of IAA, A. tumefaciens or their combination extended the life-span of giant cells, providing long-lasting feeding sites for the nematode. The auxin-mediated role of A. tumefaciens in development and reproduction of M. incognita was discussed.

  19. Behavior of Ilex paraguariensis St. Hilaire, 1822 to Meloidogyne incognita and M. paranaensis and their influence on development of plantlets

    Dbora Cristina Santiago

    2000-01-01

    Full Text Available The influence of Meloidogyne incognita and M. paranaensis on the development of mate (Ilex paraguariensis ST. Hill plantlets was assessed in greenhouse and laboratory. The experimental design was randomized. Every plot of each one of the 10 repetitions contained one mate plantlet , inoculated with 5,000 eggs of M. incognita (races 1, 2, 3 and 4 and M. paranaensis. After 120 days it was observed that mate was a reliable hostess to such nematodes and that they could finish their life cycle. Plant development was significantly modified by M. incognita, races 1 and 2. Dry and green matter weight of shoots changed according to treatment. No changes were observed in fresh root weight. The number of eggs per root was similar for M. incognita, races 1 and 2, and higher for the other treatments. The reproduction factor was above 1 for all treatments, indicating mate plants susceptibility to them.A influncia de Meloidogyne incognita e M paranaensis no desenvolvimento de mudas de erva-mate, foi avaliada em casa-de-vegetao e laboratrio. O delineamento experimental foi inteiramente casualizado, com 10 repeties, sendo cada parcela formada de 1 plntula de erva-mate/vaso, inoculada com 5000 ovos de M. incognita raas 1, 2, 3, 4 e M. paranaensis. Aos 120 dias, observou-se que a erva-mate, alm de boa hospedeira destes nematides, permitiu-lhes completar seu ciclo vital. O desenvolvimento das plantas foi significativamente afetado pelas raas 1 e 2 de M. incognita.; os pesos de matria seca e fresca da parte area sofreram alteraes conforme o tratamento. No houve alterao no peso fresco de razes e o nmero de ovos por razes foi semelhante para as raas 1 e 2 de M. incognita, sendo, porm, mais elevado nos demais tratamentos. O fator de reproduo foi superior a 1 em todos os tratamentos, indicando a susceptibilidade da erva-mate a estes agentes.

  20. Differential expression of antioxidant enzymes and PR-proteins in compatible and incompatible interactions of cowpea (Vigna unguiculata) and the root-knot nematode Meloidogyne incognita.

    Oliveira, J T A; Andrade, N C; Martins-Miranda, A S; Soares, A A; Gondim, D M F; Arajo-Filho, J H; Freire-Filho, F R; Vasconcelos, I M

    2012-02-01

    This study aimed to evaluated the resistance and susceptibility of 10 cowpea cultivars to Meloidogyne incognita in field studies and to analyze the kinetics of the enzymes superoxide dismutase, catalase, peroxidase, chitinase, ?-1,3-glucanases and cystein proteinase inhibitors in the root system of two contrasting cowpea cultivars after inoculation with M.incognita. The cultivars CE-31 and Frade Preto were highly resistant; CE-28, CE-01, CE-315, CE-237, were very resistant; CE-70 and CE-216 were moderately resistant, whereas Vita-3 and CE-109 were slightly resistant. In the roots of the highly resistant cultivar CE-31 the activity of the antioxidant enzyme superoxide dismutase increased and catalase decreased and those of the pathogenesis-related proteins chitinase, ?-1,3-glucanase, peroxidase and cystein proteinase inhibitor increased in comparison with the root system of the slightly resistant CE-109, during the course of M.incognita infestation. Thus the changes in the activities of these enzymes might be related to the smaller final population of M.incognita in CE-31 and may contribute to the high resistance of this cowpea cultivar against infection and colonization by this nematode species. PMID:22153251

  1. Extracellular protease of Pseudomonas fluorescens CHA0, a biocontrol factor with activity against the root-knot nematode Meloidogyne incognita.

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

    2005-09-01

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

    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 89.5 % and 94.7 % for galls and egg masses, respectively

  3. Presencia del marcador mi-23 de resistencia a Meloidogyne incognita como apoyo a la caracterizacin del germoplasma de tomate en Venezuela / Presence of marker Mi-23 for resistance to Meloidogyne incognita as support to tomato germplasm characterization in Venezuela

    Iris, Prez-Almeida; Ariadne, Vegas Garca; Delis, Prez; Julio, Muoz; Sergei, Malyshev.

    2015-04-01

    Full Text Available Especies del gnero Meloidogyne causan daos econmicamente significativos en cultivos como el tomate, induciendo agallas en las races y causando amarillamiento en las plantas infestadas. El empleo de cultivares resistentes garantiza una agricultura sostenible y productos de alta calidad. Se plante [...] el uso del marcador co-dominante Mi-23 ligado al gen de resistencia Mi-1.2, el cual confiere resistencia a Meloidogyne spp. como apoyo a la caracterizacin de 39 accesiones de germoplasma de tomate del INIA-CENIAP y Lara, incluyendo tomates silvestres Solanum pimpinellifolium y S. lycopersicum locales (tipo Cherry, Perita y Margariteo), poblaciones avanzadas y variedades e hbridos comerciales. El ADN se extrajo siguiendo la metodologa del CTAB y las amplificaciones de PCR se realizaron con los cebadores Mi23F/R. Los materiales genticos formaron tres grupos de acuerdo al patrn de amplificacin: 1) la poblacin 9, del INIA-Lara, con un fragmento de 400 pb, como el ADN testigo (proveniente de Belars); 2) Cherry-Lobatera, Perita Agrovitas, poblaciones 5 y 10, Cherry-189, hbridos Mariana y Salad-F1, con dos fragmentos de 450 y 400 pb; y 3) los restantes 31 materiales, entre ellos, tomates silvestres, cultivares locales, poblaciones avanzadas o promisorias, y variedades e hbridos comerciales, con un fragmento de 450 pb. Los dos primeros grupos se pueden correlacionar con genotipos resistentes homocigotos y heterocigotos, respectivamente, y el ltimo con genotipos susceptibles. La utilizacin del marcador SCAR Mi-23, ligado al gen Mi-1.2 permiti discriminar las accesiones de tomate del INIA, e identificar ocho de ellas con patrones asociados a genotipos resistentes al nematodo M. incognita, incluyendo tres poblaciones avanzadas del INIA-Lara y una local del INIA-CENIAP. Abstract in english Meloidogyne species cause economically significant damage to crops such as tomatoes, inducing galls on roots and causing yellowing of infested plants. The use of resistant cultivars ensures sustainable agriculture and high quality products. We proposed the use of co-dominant marker Mi-23, linked to [...] the resistance gene Mi-1.2, which confers resistance to Meloidogyne spp. to support the characterization of 39 accessions of tomato germplasm from INIA-CENIAP and Lara, including wild tomatoes Solanum pimpinellifolium, and S. lycopersicum local types (Cherry, Pera and Margariteo), advanced populations, and commercial hybrids and varieties. DNA was extracted following CTAB methodology, and PCR amplifications using Mi23F/R primers. Genetic materials formed three groups according to the amplification patterns: 1) population 9, from INIA-Lara, with a fragment of 400 bp, as the DNA control from Belarus; 2) Cherry-Lobatera, Perita Agrovitas, populations 5 and 10, Cherry-189, Mariana and Salad-F1 hybrids, with two fragments of 450 and 400 bp; and 3) the remaining 31 materials, among them, wild tomatoes, locals, advanced populations, and commercial varieties and hybrids, with amplification of a single 450 bp fragment. The first two groups can be correlated to homozygous and heterozygous resistance genotypes, respectively, and the last group to susceptible ones. By using the SCAR marker Mi-23, linked to gen Mi-1.2, we were able to discriminate the INIA tomatoes accessions, and identify eight of them associated with the resistance genotypes to nematode M. incognita, including three advanced populations from INIA-Lara and one local from INIA-CENIAP.

  4. Sterol Composition and Ecdysteroid Content of Eggs of the Root-knot Nematodes Meloidogyne incognita and M. arenaria

    Chitwood, David J.; McClure, Michael A.; Feldlaufer, Mark F.; Lusby, William R.; Oliver, Tames E.

    1987-01-01

    Free and esterified sterols of eggs of the root-knot nematodes Meloidogyne incognita races 2 and 3 and M. arenaria race 1 were isolated and identified by gas-liquid chromatography-mass spectrometry. The major sterols of eggs of each race were 24-ethylcholesterol (33.4-38.8% of total sterol), 24-ethylcholestanol (18.3-25.3%), 24-methylcholesterol (8.6-11.7%), 24-methylcholestanol (7.7-12.5%), and cholesterol (4.6-11.6%). Consequently, the major metabolic transformation performed by Meloidogyne...

  5. Influence of chilling and freezing temperatures on infectivity of Meloidogyne incognita and M. hapla.

    Vrain, T C

    1978-04-01

    Egg masses and second-stage larvae of Meloidogyne incognita and M. hapla in soil were exposed to temperatures ranging from 20 to -8 C. Temperature was lowered in 2-day intervals to 16, 12, 8, 4, 0, -4, and -8 C, and the nematodes remained at 4, 0, -4, or -8 C for 18, 14, 10, or 6 days, respectively. Unhatched larvae of both species were more resistant to low temperatures than were embryonic stages. Within the eggs of M. incognita, 7.5% of embryos and 48% of larval stages survived 14 days at 0 C, whereas 9% of embryos and 90% of larval stages in the eggs of M. hapla survived 10 days at -4 C. Second-stage larvae of both species remained infective in sol.1 at 4 or 0 C, but were injured at -4 and -8 C. Infectivily of these larvae was lower in saturated soil than in soil at 51 cm moisture tension at all temperatures. PMID:19305834

  6. In-vitro Assays of Meloidogyne incognita and Heterodera glycines for Detection of Nematode-antagonistic Fungal Compounds

    Nitao, James K.; Meyer, Susan l. F.; Chitwood, David J.

    1999-01-01

    In-vitro methods were developed to test fungi for production of metabolites affecting nematode egg hatch and mobility of second-stage juveniles. Separate assays were developed for two nematodes: root-knot nematode (Meloidogyne incognita) and soybean cyst nematode (Heterodera glycines). For egg hatch to be successfully assayed, eggs must first be surface-disinfested to avoid the confounding effects of incidental microbial growth facilitated by the fungal culture medium. Sodium hypochlorite was...

  7. Nematocidal Flavone-C-Glycosides against the Root-Knot Nematode (Meloidogyne incognita) from Arisaema erubescens Tubers

    Zhi Long Liu; Yong Yan Wang; Zhi Wei Deng; Qi Zhi Liu; Cheng Fang Wang; Chun Qi Bai; Hai Ming Zhang; Shu Shan Du

    2011-01-01

    A screening of several Chinese medicinal herbs for nematicidal properties showed that Arisaema erubescens (Wall.) Schott tubers possessed significant nematicidal activity against the root-knot nematode (Meloidogyne incognita). From the ethanol extract, two nematicidal flavone-C-glycosides were isolated by bioassay-guided fractionation. The compounds were identified as schaftoside and isoschaftoside on the basis of their phytochemical and spectral data. Schaftoside and isoschaftoside possessed...

  8. Effects of Soil Solarization and Organic Amendment Treatments for Controlling Meloidogyne incognita in Tomato Cultivars in Western Anatolia

    KA?KAVALCI, Galip

    2007-01-01

    The efficacy of soil solarization, Dazomet, chicken manure (CM), olive processing waste (OPW), and soil solarization in combination with CM or OPW or half doses of Dazomet against Meloidogyne incognita on tomato cultivars was investigated in greenhouses in western Anatolia, Turkey, between 2002 and 2004. The maximum soil temperature average was increased 47.1 C by soil solarization alone at the 15 cm soil depth of soil in the first year. Soil solarization alone and in combination with CM inc...

  9. Mycorrhiza–induced resistance against the root-knot nematode Meloidogyne incognita involves priming of defense gene responses in tomato

    Vos, C. de; De Waele, D.; van Tuinen, D.; Chatagnier, O.; Schouteden, N.

    2013-01-01

    Arbuscular mycorrhizal fungi (AMF) have great potential as biocontrol organisms against the rooteknot nematode Meloidogyne incognita which causes severe gall formation in plants, but knowledge about the underlying molecular mechanisms involved in the biocontrol of nematodes is scarce. In the present study, suppression subtractive hybridization (SSH) was used to investigate plant genes that are specifically up-regulated in tomato roots (Solanum lycopersicum cv. Marmande) pre-coloni...

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

    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 Fusarium solani f. sp. piperi Albuquerque was initiated to search for a biological cause of "yellow disease" of black pepper.This disease was described already in 1932 by Van der Vecht as "geelziektel" and its symptoms on the aerial parts of the pepper plants were yellowing of the leave...

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

    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.

  12. Efeito de extratos aquosos de espécies de Asteraceae sobre Meloidogyne incognita Effect of aqueous extracts of Asteraceae species on Meloidogyne incognita

    Isabel Cristina Madeira Ferreira

    2013-03-01

    Full Text Available Estudou-se, in vitro e in vivo a atividade nematicida dos extratos aquosos de vedélia (Sphagneticola trilobata, erva-de-touro (Tridax procumbens, cravo-de-defunto (Tagetes patula, girassol mexicano (Tithonia diversifolia, botão de ouro (Unxia suffruticosa e zínia (Zinnia peruviana, sobre Meloidogyne incognita. Os extratos foram preparados na proporção de 1,0g do material seco e triturado para 10mL de água destilada e armazenados por 24h, sendo seguidamente utilizados nos experimentos. Nos testes in vitro, foram depositados 4,0mL do extrato bruto e 2,0mL de uma suspensão aquosa contendo 200 ovos do nematóide em placas de Petri de 5cm de diâmetro e, quinze dias após, procedeu-se a contagem do número de juvenis eclodidos e dos ovos remanescentes para o cálculo das porcentagens de eclosão. Nos testes in vivo, os extratos foram aplicados, separadamente, via pulverização foliar, tratamento de raiz e vertido no solo, semanalmente durante 60 dias. Como testemunha utilizou-se apenas água nos dois experimentos. No ensaio in vitro observou-se que todos os extratos foram eficientes na redução da eclosão de juvenis de M. incognita quando comparados à testemunha, as porcentagens de redução foram 89,96%, 91,13%, 92,48%, 92,72%, 93,2% e 97,48% para erva-de-touro, cravo-de-defunto, girassol mexicano, vedélia, botão de ouro e zínia, respectivamente, e no ensaio in vivo, que os tratamentos não exerceram nenhum efeito sobre o peso do sistema radicular dos tomateiros, no entanto, observou-se que os resultados diferiram entre as espécies utilizadas e a forma de aplicação do extrato na avaliação do peso fresco da parte aérea das plantas. Quanto ao fator de reprodução, observou-se que nenhum dos extratos apresentou diferença estatística em relação à testemunha, no entanto, quando se compara as diferentes formas de aplicação dos mesmos, observa-se que houve diferença estatística quando os extratos de erva de touro e girassol mexicano foram aplicados via pulverização foliar e no tratamento de raiz, contudo, não houve diferença quando estes extratos foram aplicados em forma de rega no solo.The nematicide activity of aqueous extracts of Wedelia (Sphagneticola trilobata, tridax daisy (Tridax procumbens, marigold (Tagetes patula, Mexican sunflower (Tithonia diversifolia, "botão de ouro" (Unxia suffruticosa and Peruvian zinnia (Zinnia peruviana was studied in vitro and in vivo on Meloidogyne incognita. The extracts were prepared at a ratio of 1.0 g of dry and crushed material to 10 ml of distilled water, stored for 24 hours, and then used in the experiments. In in vitro tests, 4.0 mL of crude extract and 2.0 ml of an aqueous suspension containing 200 nematode eggs were deposited on Petri plates of 5cm diameter and, fifteen days later, the number of hatched juveniles and the remaining eggs were counted to calculate the percentages of hatching. In in vivo tests, the extracts were separately applied by leaf spraying, root treatment and pouring onto the soil, weekly for 60 days. As control, only water was used in both experiments. The in vitro test showed that all extracts were effective in reducing the hatching of juveniles of M. incognita when compared to the control; the reduction percentages were 89.96%, 91.13%, 92.48%, 92.72%, 93.2% and 97.48% for tridax daisy, marigold, Mexican sunflower, Wedelia, "botão de ouro" and Peruvian zinnia, respectively, while in the in vivo assay, treatments did not have any effect on the root system weight of tomato plants; however, results differed between the used species and the way of application of the extract in the evaluation of the fresh weight of shoots. As to the reproduction rate, none of the extracts showed a statistical difference, compared to control; however, comparing the different ways of application, there was statistical difference when the extracts of tridax daisy and Mexican sunflower were applied through leaf spraying and root treatment, but there was no difference when these extracts were applied as irrigation on the soil.

  13. Effects of Peanut-Tobacco Rotations on Population Dynamics of Meloidogyne arenaria in Mixed Race Populations

    Hirunsalee, Anan; Barker, K. R.; Beute, M.K.

    1995-01-01

    A 3-year microplot study was initiated to characterize the population dynamics, reproduction potential, and survivorship of single or mixed populations of Meloidogyne arenaria race 1 (Ma1) and race 2 (Ma2), as affected by crop rotations of peanut 'Florigiant' and M. incognita races 1 and 3-resistant 'McNair 373' and susceptible 'Coker 371-Gold' tobacco. Infection, reproduction, and root damage by Ma2 on peanut and by Ma1 on resistant tobacco were limited in the first year. Infection, reproduc...

  14. Histological mechanisms of the resistance conferred by the Ma gene against Meloidogyne incognita in Prunus spp.

    Khallouk, Samira; Voisin, Roger; Van Ghelder, Cyril; Engler, Gilbert; Amiri, Saïd; Esmenjaud, Daniel

    2011-08-01

    The Ma gene from Myrobalan plum is a TNL gene that confers a high-level resistance to all root-knot nematodes of major economic importance, including Meloidogyne incognita, M. javanica, M. arenaria, and M. enterolobii. The nematode behavior in the roots and the corresponding histological mechanisms of the Ma resistance to M. incognita in the resistant (R) accessions of the plum 'P.2175' and the interspecific hybrid P.2175×almond-peach '35', carrying the Ma1 allele (Ma1/ma), were characterized in comparison with the susceptible (S) accessions in the plum 'P.2032' and the interspecific hybrid P.2175×almond-peach '253' (ma/ma). Second-stage juveniles (J2s) were inoculated in micropropagated plantlets grown in soil substrate under controlled conditions at 25°C. Nematodes penetrated both R and S plants preferentially along the apical zone or close to the young lateral buds and moved via similar routes. Then they migrated into the cortex downward in the direction of the apex and turned up in the meristematic apical region to colonize the differentiating stele. In R accessions, motile J2s neither swelled nor developed into J3s, and initiation of feeding sites was never observed. This complete absence of gall symptoms is associated with cell necroses and corresponding hypersensitive-like reaction (HLR) phenotypes occurring either in the stele or in the meristematic apical region or in the cortex. Nematode attacks often disorganized the meristematic apical tissues of R accessions, which induced the development of subterminal lateral roots replacing primary terminal apices and, thus, provided an active resistance reaction to HLR damage. PMID:21446787

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

    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. PMID:24050256

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

    Wergin, W P; Yaklich, R W; Chitwood, D J; Erbe, E F

    1999-12-01

    Solid CO (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 degrees C to -59 degrees C. One day after treatment with the dry ice, the temperature of the soil was allowed to equilibrate with that of the greenhouse, and susceptible tomato seedlings were planted in pots containing infested soil treated or untreated (controls) with dry ice. After 5 weeks, roots were removed from the pots and nematode eggs were extracted and counted. Plants grown in soil infested with eggs and receiving dry ice treatment had less than 1% of the eggs found in the controls; plants from soil infested with root fragments and receiving dry ice treatment had less than 4% of the eggs found in controls. Dry ice used to lower soil temperature may have potential as a cryonematicide. PMID:19270918

  17. Efeitos do nível de inóculo de Meloidogyne incognita em algodoeiro Effects of low inoculum level of Meloidogyne incognita on cotton plants

    MARLUCI MUNDIN ABRÃO

    2001-01-01

    Full Text Available Pesquisas acerca da fisiologia de plantas em resposta ao ataque de nematóides normalmente são feitas com doses altas de inóculo, quer sejam ovos ou juvenis de segundo estágio. Diferentemente, as avaliações da resistência de plantas a nematóides em programas de melhoramento são realizadas com doses bastante inferiores. Neste estudo acompanhou-se a variação de alguns parâmetros fisiológicos em algodão, em resposta à aplicação de baixas doses de inóculo de Meloidogyne incognita raça 3. Duas cultivares foram utilizadas, Acala e IAC-20, respectivamente suscetível e moderadamente resistente. Plântulas com duas folhas receberam 500 ou 5.000 ovos e, 90 dias depois, foram comparadas a plantas que não receberam o inóculo, quanto à massa da parte aérea e raízes, fotossíntese, atividade da enzima redutase do nitrato e teores de clorofila e açúcares solúveis. Aos 90 dias algumas plantas também foram submetidas à deficiência hídrica e o potencial da água determinado nas folhas. O maior nível de inóculo levou à redução da parte aérea (massa de folhas em 'Acala'. Com 500 ovos parece ter ocorrido um estímulo em ambas as cultivares, uma vez que houve tendência de maior crescimento da parte aérea. Em 'Acala' houve maior crescimento de raiz com o aumento do inóculo, provavelmente devido à emissão de raízes secundárias nos pontos de penetração do nematóide e também pela formação de galhas. Houve aumento dos teores de clorofila e de açúcares solúveis, bem como da fotossíntese, com o aumento do inóculo. Discute-se se tal ocorrência deve-se à maior demanda de fotoassimilados para suportar o crescimento de raízes, em 'Acala'. Em IAC-20 esse fato estaria ligado aos mecanismos de defesa induzidos pelo ataque do nematóide. Após o estresse hídrico o potencial da água diminuiu em 'IAC-20' e aumentou na 'Acala', com o aumento do inóculo. A elevação do potencial da água, nesta última cultivar, poderia estar ligada ao crescimento das raízes e, principalmente, à emissão de novas raízes secundárias, ao passo que a resposta em 'IAC-20' seria a previsível, ou seja, de deficiência hídrica.Investigations on physiological responses of plants to nematode are usually carried out with plants inoculated with high number of eggs or second-stage juveniles. On the other hand, resistance against nematodes in plant breeding programs is evaluated with low number of inoculum. The aim of this research was to study some physiological responses of cotton plants inoculated with low inoculum levels of Meloidogyne incognita race 3. Two cultivars were used, Acala and IAC-20, susceptible and moderately resistant hosts respectively. Seedlings with 500 or 5,000 eggs were compared with control plants at 90 days post inoculation. The following aspects were assessed: shoot and root masses, photosynthesis, activity of the enzyme nitrate reductase, and chlorophyll and soluble sugar contents. At 90 days a water stress was imposed to some plants and the leaf water potentials determined. At 5,000 eggs, 'Acala' had a shoot reduction (leafmass. With 500 eggs, there was an estimulation of shoot growth in both cultivars, as revealed by a shootmass increase There was a clear increase on root growth of 'Acala' which was directly related to the inoculum levels. This response was probably caused by emission of new secondary roots and nematode galls formation. Chlorophyll and sugar content, and photosynthesis increased with the increase of inoculum levels, suggesting a response to support root growth in 'Acala'. In 'IAC-20' these higher values would be related with the energy demanded by defense mechanisms against the nematode. The imposed water stress caused a decrease on leaf water potential in 'IAC-20', but an increase in 'Acala' with increasing inoculum levels. The observed increase in the later cultivar might be related with the root growth, mainly due to emission of new secondary roots, while 'IAC 20' water stress response, would be considered as a pattern.

  18. 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

    Ariane C Salata; Erick Vinicius Bertolini; Felipe O Magro; Antonio II Cardoso; Silvia Renata S Wilcken

    2012-01-01

    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 h...

  19. Avaliação da resistência dê cafeeiros às raças dê Meloidogyne incognita Evaluation of coffea resistance to Meloidogyne incognita races

    Rubens Rodolfo Albuquerque Lordello; Ana Ines Lucena Lordello

    1987-01-01

    No Centro Experimental de Campinas do Instituto Agronômico, de abril de 1984 a agosto de 1985, realizaram-se dois experimentos, em vasos, para avaliar a resistência de mudas de sete linhagens de Coffea arabica ('Mundo Novo': CP388-17, CP379-19, CP501 e MP376-4; 'Catuaí Amarelo' H2077-2-5-62 e 'Catuaí Vermelho' H2077-2-5-81, e 'Caturra Amarelo') e dois de C. canephora (Robusta: 'Guarini' col. 10 e 'Kouillon' col. 67-14) às quatro raças de Meloidogyne incognita. No primeiro experimento, cada mu...

  20. Nematocidal Flavone-C-Glycosides against the Root-Knot Nematode (Meloidogyne incognita from Arisaema erubescens Tubers

    Zhi Long Liu

    2011-06-01

    Full Text Available A screening of several Chinese medicinal herbs for nematicidal properties showed that Arisaema erubescens (Wall. Schott tubers possessed significant nematicidal activity against the root-knot nematode (Meloidogyne incognita. From the ethanol extract, two nematicidal flavone-C-glycosides were isolated by bioassay-guided fractionation. The compounds were identified as schaftoside and isoschaftoside on the basis of their phytochemical and spectral data. Schaftoside and isoschaftoside possessed strong nematicidal activity against M. incognita (LC50 = 114.66 ?g/mL and 323.09 ?g/mL, respectively while the crude extract of A. erubescens exhibited nematicidal activity against the root-knot nematode with a LC50 value of 258.11 ?g/mL.

  1. EVALUATION OF MAIZE, SORGHUM AND MILLET GENOTYPES FOR RESISTANCE AGAINST Meloidogyne javanica AND M. incognita RACE 3

    FREDOLINO GIACOMINI DOS SANTOS

    2002-12-01

    Full Text Available The use of nematode resistant crops in rotations prevents losses in susceptiblecrops. The reproduction of Meloidogyne javanica and M. incognita race 3 in maize, sorghumand millet genotypes in greenhouse conditions where evaluated. The plants were grown ingreenhouse conditions, inoculated with 5.000 nematode eggs and evaluated after 60 days.Tomato plants were used as inoculums efficiency check. The egg production of M. incognitawas higher than M. javanica in all maize genotypes. M. javanica presented low reproduction(FR<1 in all genotypes. The maize genotypes CMS 100 02 2, HS 723x724, 97 HT 14 A,BRS 3123, BRS 2114, CMS 14 B, CMS 2000 17 A, CMS 99 14 C, 52 HT03-QPM, HS111764040, and all sorghum and millet genotypes were resistant to M. incognita, resulting in low egg production. The commercial resistant genotypes of corn were indicated to nematodeinfested areas.

  2. Management of Meloidogyne incognita race 3 and Macrophomina phaseolina by fungus culture filtrates and Bacillus subtilis on chickpea

    Siddiqui, Z.A.; Mahmood, I.

    1995-01-01

    #Bacillus subtilis$ et des filtrats de culture des champignons #Aspergillus niger, Curvularia tuberculata$ et #Penicillium coryophilum$ ont été utilisés, seuls ou en combinaison, comme traitement de semences pour protéger le pois chiche contre une maladie racinaire complexe associant le nématode "Meloidogyne incognita$ race 3 et le champignon #Macrophomina phaseolina$. D'une manière générale, les traitements à l'aide de ces quatre agents, seuls ou en combinaison, accroissent le poids sec et l...

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

    Seo, Yunhee; Park, Jiyeong; Kim, Yong Su; Park, Yong; KIM, Young Ho

    2014-01-01

    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 coefficien...

  4. Genome-wide survey and analysis of microsatellites in nematodes, with a focus on the plant-parasitic species Meloidogyne incognita

    Guillemaud Thomas

    2010-10-01

    Full Text Available Abstract Background Microsatellites are the most popular source of molecular markers for studying population genetic variation in eukaryotes. However, few data are currently available about their genomic distribution and abundance across the phylum Nematoda. The recent completion of the genomes of several nematode species, including Meloidogyne incognita, a major agricultural pest worldwide, now opens the way for a comparative survey and analysis of microsatellites in these organisms. Results Using MsatFinder, the total numbers of 1-6 bp perfect microsatellites detected in the complete genomes of five nematode species (Brugia malayi, Caenorhabditis elegans, M. hapla, M. incognita, Pristionchus pacificus ranged from 2,842 to 61,547, and covered from 0.09 to 1.20% of the nematode genomes. Under our search criteria, the most common repeat motifs for each length class varied according to the different nematode species considered, with no obvious relation to the AT-richness of their genomes. Overall, (ATn, (AGn and (CTn were the three most frequent dinucleotide microsatellite motifs found in the five genomes considered. Except for two motifs in P. pacificus, all the most frequent trinucleotide motifs were AT-rich, with (AATn and (ATTn being the only common to the five nematode species. A particular attention was paid to the microsatellite content of the plant-parasitic species M. incognita. In this species, a repertoire of 4,880 microsatellite loci was identified, from which 2,183 appeared suitable to design markers for population genetic studies. Interestingly, 1,094 microsatellites were identified in 801 predicted protein-coding regions, 99% of them being trinucleotides. When compared against the InterPro domain database, 497 of these CDS were successfully annotated, and further assigned to Gene Ontology terms. Conclusions Contrasted patterns of microsatellite abundance and diversity were characterized in five nematode genomes, even in the case of two closely related Meloidogyne species. 2,245 di- to hexanucleotide loci were identified in the genome of M. incognita, providing adequate material for the future development of a wide range of microsatellite markers in this major plant parasite.

  5. Efeito de extratos aquosos de espcies de Asteraceae sobre Meloidogyne incognita

    Isabel Cristina Madeira Ferreira

    2013-03-01

    Full Text Available Estudou-se, in vitro e in vivo a atividade nematicida dos extratos aquosos de vedlia (Sphagneticola trilobata, erva-de-touro (Tridax procumbens, cravo-de-defunto (Tagetes patula, girassol mexicano (Tithonia diversifolia, boto de ouro (Unxia suffruticosa e znia (Zinnia peruviana, sobre Meloidogyne incognita. Os extratos foram preparados na proporo de 1,0g do material seco e triturado para 10mL de gua destilada e armazenados por 24h, sendo seguidamente utilizados nos experimentos. Nos testes in vitro, foram depositados 4,0mL do extrato bruto e 2,0mL de uma suspenso aquosa contendo 200 ovos do nematide em placas de Petri de 5cm de dimetro e, quinze dias aps, procedeu-se a contagem do nmero de juvenis eclodidos e dos ovos remanescentes para o clculo das porcentagens de ecloso. Nos testes in vivo, os extratos foram aplicados, separadamente, via pulverizao foliar, tratamento de raiz e vertido no solo, semanalmente durante 60 dias. Como testemunha utilizou-se apenas gua nos dois experimentos. No ensaio in vitro observou-se que todos os extratos foram eficientes na reduo da ecloso de juvenis de M. incognita quando comparados testemunha, as porcentagens de reduo foram 89,96%, 91,13%, 92,48%, 92,72%, 93,2% e 97,48% para erva-de-touro, cravo-de-defunto, girassol mexicano, vedlia, boto de ouro e znia, respectivamente, e no ensaio in vivo, que os tratamentos no exerceram nenhum efeito sobre o peso do sistema radicular dos tomateiros, no entanto, observou-se que os resultados diferiram entre as espcies utilizadas e a forma de aplicao do extrato na avaliao do peso fresco da parte area das plantas. Quanto ao fator de reproduo, observou-se que nenhum dos extratos apresentou diferena estatstica em relao testemunha, no entanto, quando se compara as diferentes formas de aplicao dos mesmos, observa-se que houve diferena estatstica quando os extratos de erva de touro e girassol mexicano foram aplicados via pulverizao foliar e no tratamento de raiz, contudo, no houve diferena quando estes extratos foram aplicados em forma de rega no solo.

  6. The Feeding Behavior of Adult Root-knot Nematodes (Meloidogyne incognita) in Rose Balsam and Tomato.

    Miyashita, Nao; Yabu, Tetsuo; Kurihara, Takayuki; Koga, Hironori

    2014-09-01

    Meloidogyne incognita is a parasitic root-knot nematode that causes considerable yield loss in a wide range of plants. In this study we documented the movement of adult female nematodes for more than 2 hr in micro-slices of infected tomato (Solanum lycopersicum) and rose balsam (Impatiens balsamina) plants using light and video microscopy. Stylet thrusting was followed by short pumping actions of the esophagus, dorsal esophageal gland ampulla, and metacorpal bulb. Regular thrusting was normally accompanied by head turning and always preceded continuous stylet thrusting aimed at a single point (for 20 to 90 sec). Females often held the stylet in a protruded position, while pulsating the metacorpus bulb, for about 30 sec. Subsequently, the stylet was paused in a retracted position for 5 to 40 sec. This sequence of behavior took 290 to 380 sec to complete. The procedure developed in this study provides a useful cytological technique to investigate the interaction between root-knot nematodes and the giant cells formed by infected plants. Scanning electron microscopy revealed that the head of the adult nematode was located in the narrow intercellular spaces among several giant cells. The anterior part of the head of the adult was folded like a concertina, whereas that of the second-stage juvenile was not. The labial disc and medial lips of second-stage juveniles seemed expanded and sturdy, whereas those of the adult were star-shaped, appeared to be contracted, and softer. These morphological differences in the heads of adult and second-stage juveniles are discussed with respect to their movement. PMID:25276004

  7. Comparison between the N and Me3 gene conferring resistance to the root-knot nematode (Meloidogyne incognita) in genetically different pepper lines (Capsicum annuun).

    Genetic resistance to Meloidogyne incognita in pepper (Capsicum annuum L.) has been well characterized for the N and Me3 resistance genes. However, there are no studies comparing the effects of these two genes directly or are there studies investigating the combined effects when both genes are pres...

  8. Nematicidal activities of 4-quinolone alkaloids isolated from the aerial part of Triumfetta grandidens against Meloidogyne incognita.

    Jang, Ja Yeong; Dang, Quang Le; Choi, Yong Ho; Choi, Gyung Ja; Jang, Kyoung Soo; Cha, Byeongjin; Luu, Ngoc Hoang; Kim, Jin-Cheol

    2015-01-14

    The methanol extract of the aerial part of Triumfetta grandidens (Tiliaceae) was highly active against Meloidogyne incognita, with second-stage juveniles (J2s) mortality of 100% at 500 ?g/mL at 48 h post-exposure. Two 4-quinolone alkaloids, waltherione E (1), a new alkaloid, and waltherione A (2), were isolated and identified as nematicidal compounds through bioassay-guided fractionation and instrumental analysis. The nematicidal activities of the isolated compounds against M. incognita were evaluated on the basis of mortality and effect on egg hatching. Compounds 1 and 2 exhibited high mortalities against J2s of M. incognita, with EC50 values of 0.09 and 0.27 ?g/mL at 48 h, respectively. Compounds 1 and 2 also exhibited a considerable inhibitory effect on egg hatching, which inhibited 91.9 and 87.4% of egg hatching, respectively, after 7 days of exposure at a concentration of 1.25 ?g/mL. The biological activities of the two 4-quinolone alkaloids were comparable to those of abamectin. In addition, pot experiments using the crude extract of the aerial part of T. grandidens showed that it completely suppressed the formation of gall on roots of plants at a concentration of 1000 ?g/mL. These results suggest that T. grandidens and its bioactive 4-quinolone alkaloids can be used as a potent botanical nematicide in organic agriculture. PMID:25494674

  9. Inheritance and Identification of a Major Quantitative Trait Locus (QTL) that Confers Resistance to Meloidogyne incognita and a Novel QTL for Plant Height in Sweet Sorghum.

    Harris-Shultz, Karen R; Davis, Richard F; Knoll, Joseph E; Anderson, William; Wang, Hongliang

    2015-12-01

    Southern root-knot nematodes (Meloidogyne incognita) are a pest on many economically important row crop and vegetable species and management relies on chemicals, plant resistance, and cultural practices such as crop rotation. Little is known about the inheritance of resistance to M. incognita or the genomic regions associated with resistance in sorghum (Sorghum bicolor). In this study, an F2 population (n = 130) was developed between the resistant sweet sorghum cultivar 'Honey Drip' and the susceptible sweet cultivar 'Collier'. Each F2 plant was phenotyped for stalk weight, height, juice Brix, root weight, total eggs, and eggs per gram of root. Strong correlations were observed between eggs per gram of root and total eggs, height and stalk weight, and between two measurements of Brix. Genotyping-by-sequencing was used to generate single nucleotide polymorphism markers. The G-Model, single marker analysis, interval mapping, and composite interval mapping were used to identify a major quantitative trait locus (QTL) on chromosome 3 for total eggs and eggs per gram of root. Furthermore, a new QTL for plant height was also discovered on chromosome 3. Simple sequence repeat markers were developed in the total eggs and eggs per gram of root QTL region and the markers flanking the resistance gene are 4.7 and 2.4 cM away. These markers can be utilized to move the southern root-knot nematode resistance gene from Honey Drip to any sorghum line. PMID:26574655

  10. Multiplex PCR for the simultaneous identification and detection of Meloidogyne incognita, M. enterolobii, and M. javanica using DNA extracted directly from individual galls.

    Hu, M X; Zhuo, K; Liao, J L

    2011-11-01

    Meloidogyne incognita, M. enterolobii, and M. javanica are the most widespread species of root-knot nematodes in South China, affecting many economically important crops, ornamental plants, and fruit trees. In this study, one pair of Meloidogyne universal primers was designed and three pairs of species-specific primers were employed successfully to rapidly detect and identify M. incognita, M. enterolobii, and M. javanica by multiplex polymerase chain reaction (PCR) using DNA extracted from individual galls. Multiplex PCR from all M. incognita, M. enterolobii, and M. javanica isolates generated two fragments of ≈500 and 1,000, 500 and 200, and 500 and 700 bp, respectively. The 500-bp fragment is the internal positive control fragment of rDNA 28S D2/D3 resulting from the use of the universal primers. Other Meloidogyne spp. included in this study generated only one fragment of ≈500 bp in size. Using this approach, M. incognita, M. enterolobii, and M. javanica were identified and detected using DNA extracted directly from individual galls containing the Meloidogyne spp. at various stages of their life cycle. Moreover, the percentage of positive PCR amplification increased with nematode development and detection was usually easy after the late stage of the second-stage juvenile. The protocol was applied to galls from naturally infested roots and the results were found to be fast, sensitive, robust, and accurate. This present study is the first to provide a definitive diagnostic tool for M. incognita, M. enterolobii, and M. javanica using DNA extracted directly from individual galls using a one-step multiplex PCR technique. PMID:21770774

  11. Registro da ocorrncia de Meloidogyne incognita no porta-enxerto 'IAC 766-Campinas' no estado de Pernambuco e reao de porta-enxertos e de cultivares copa de videira a Meloidogyne spp.

    Lcia Somavilla

    2012-09-01

    Full Text Available Relata-se a ocorrncia de Meloidogyne incognita (Est. I2 em pomar de videira na cidade de Petrolina, Pernambuco. Plantas da cultivar Festival enxertadas sobre 'IAC 766-Campinas', atacadas por Meloidogyne incognita, apresentavam sintomas de menor vigor, folhas amarelecidas e folhagem mais esparsa, e razes com numerosas galhas em meio ao cultivo de feijo-de-porco (Canavalia ensiformis, tambm atacado pelo nematoide. Com o objetivo de avaliar a resistncia de quatro porta-enxertos tropicais, oito de clima temperado, e as cultivares Nigara Rosada e Chardonnay quanto reao a M. incognita e M. arenaria, em casa de vegetao, realizou-se este trabalho. Mudas das videiras, mantidas em vaso com solo esterilizado, foram inoculadas com 10.000 ovos + J2 de M. incognita ou M. arenaria por planta. Decorridos oito meses da inoculao, cada planta foi avaliada quanto ao nmero de galhas e nmero de ovos por planta, determinando-se, a seguir, o fator de reproduo de cada espcie do nematoide (FR=populao inicial/populao final nos diferentes materiais testados. Entre os porta-enxertos avaliados, 'Harmony', 'Salt Creek', '1103 Paulsen', 'IAC 572-Jales', 'IAC 313-Tropical', 'K5BB Kober' e 'SO4', foram resistentes (FR1,00 ao nematoide. No entanto, ambas as cultivares copa foram suscetveis s duas espcies de Meloidogyne testadas.

  12. Preliminary evaluation of meloidogyne incognita race 3 reproduction on garden pea cultivars in Brazil/ Avaliação preliminar da reprodução de Meloidogyne incognita raça 3 em cultivares de ervilha no Brasil

    Luiz Carlos Camargo Barbosa Ferraz

    2000-01-01

    Full Text Available Thirteen garden pea cultivars, were assessed for the reproductive rate of the root-knot nematode Meloidogyne incognita race 3 under greenhouse conditions. Two-week old plants growing were inoculated with 5.000 eggs. The nematode reproduction data was determined 55 days later according to the three adopted evaluation criteria (root-gall and egg-mass indexes, reproduction factor, percentage of reduction of the reproduction factor in relation to the susceptible standard cultivar. The tested cultivars were rated as highly susceptible ('Trolly'. 'Jurema', susceptible ('Luiza'. 'Mini'. 'Asterix', 'Verde Temprana' or moderately susceptible ('Marina', 'Telephone'., 'Dileta'. 'Bolero', 'Flávia'. 'Viçosa', and 'Maria' hosts for the nematode.Avaliaram-se as taxas reprodutivas e caracterizaram-se as reações de 13 cut tiveres de ervilha em relação ao nematóide de galhas Meloidogyne incognita raça 3, em casa-de-vegetação. Plantas com duas semanas de idade, foram inoculadas com 5000 ovos do nematóide. As avaliações foram realizadas após 55 dias com base nos critérios - índices de galhas/índices de massas de ovos, fator de reprodução e porcentagem de redução do fator de reprodução. Duas cultivares foram consideradas hospedeiras altamente suscetíveis (‘Trolly’, ‘Jurema’, cinco suscetíveis ('Luíza', 'Mini', 'Asterix', 'Verde Temprana', 'Telefone' e seis moderadamente suscetíveis ('Marina'. 'Dileta', 'Boiero'. 'Flávia'. 'Viçosa', 'Maria'.

  13. Identification of Meloidogyne incognita, M. javanica and M. arenaria using sequence characterised amplified region (SCAR) based PCR assays

    2000-01-01

    Trois marqueurs of d'ADN polymorphique amplifié au hasard (RAPD) OPA-12(sub420), OPB-O6(sub 1200) et OPA-OI(sub 700), respectivement spécifiques des espèces de nématodes #Meloidogyne arenaria$, #M. incognita$ et #M. javanica$, ont été identifiés. Après le séquençage de ces produits RAPD-PCR, les amorces les plus longues de 18 à 23 nucléotides ont été choisies pour compléter les séquences terminales d'ADN des fragments d'ADN. Cela a conduit à trois paires d'amorces spécifiques de l'espèce, uti...

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

    Seo, Yunhee; Park, Jiyeong; Kim, Yong Su; Park, Yong; Kim, Young Ho

    2014-03-01

    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. PMID:25288988

  15. EFECTO DEL VERMICOMPOST Y QUITINA SOBRE EL CONTROL DE Meloidogyne incognita EN TOMATE A NIVEL DE INVERNADERO

    Leida Castro

    2011-01-01

    Full Text Available Meloidogyne incognita es un nematodo endoparsito sedentario, de penetracin total y formador de ndulos radicales; tiene una amplia distribucin geogrfica y causa prdidas agrcolas importantes. Recientemente se han utilizado abonos orgnicos y compuestos como la quitina en la supresin de plagas y enfermedades de plantas. El objetivo de esta investigacin fue evaluar el efecto de la aplicacin de vermicompost de estircol bovino y su enriquecimiento con quitina, sobre la infeccin de M. incognita en plantas de tomate var. Hayslip bajo condiciones de invernadero. Para esto se inocularon las plantas con 5000 unidades de inculo (huevos+juveniles en segundo estado por maceta y se compararon con controles que fueron sembrados en suelo sin enmienda orgnica o quitina. La evaluacin se llev a cabo 60 das despus y se midi el peso fresco areo y radical, peso seco areo, poblacin total de nematodos en raz y suelo, ndice de ndulos radicales (INR, ndice de masas de huevos (IMH, el factor de reproduccin del nematodo (FR y recuento de grupos funcionales (hongos, bacterias y actinomicetes. La adicin al suelo de vermicompost provoc un incremento en las variables peso fresco y seco foliar y peso fresco radical: a mayor porcentaje de vermicompost, mayor incremento; as mismo, la aplicacin del vermicompost redujo la cantidad del nematodo en raz y en suelo. La aplicacin de quitina acentu estos resultados, obtenindose el menor factor de reproduccin 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 aplicacin de quitina como enmienda nica solo afect la poblacin de hongos en el suelo, mientras que la de actinomicetes aument en los tratamientos enmendados.

  16. Resistência do Abacaxizeiro 'Turiaçu' a Meloidogyne arenaria, M. enterolobii, M. incognita e M. javanica

    Gilson Soares da Silva

    2015-09-01

    Full Text Available Neste trabalho avaliou-se, em condições de casa de vegetação, a reação do abacaxizeiro 'Turiaçu' [Ananas comosus (L. Merril 'Turiaçu'] a Meloidogyne arenaria, M. enterolobii, M. incognita e M. javanica. Mudas tipo filhote foram plantadas em vasos com capacidade de 3L contendo solo autoclavado. Quando as mudas apresentaram raízes desenvolvidas, foram inoculadas com 5000 ovos de cada espécie do nematoide, separadamente. Foi adotado um delineamento inteiramente casualizado com dez repetições. Cento e cinquenta dias após a inoculação, as plantas foram avaliadas quanto ao fator de reprodução do nematoide (FR=população final/população inicial. O abacaxizeiro 'Turiaçu' mostrou-se altamente resistente às quatro espécies de Meloidogyne, com fatores de reprodução variando entre 0,00 a 0,03.

  17. Influence of High Dilutions of Cina for the Control of Meloidogyne incognita in Tomato Plants

    Rafael Augusto Swarowsky; José Renato Stangarlin; Odair José Kunh; Rogério Lopes Estevez; Thaísa Muriel Mioranza; Mônica Anghinoni Muller

    2014-01-01

    Considering the importance of the tomato crop and the high costs for controlling Meloidogyne incognita with resistant cultivar or nematicides, it is necessary for the search of new alternatives to manage the root-knot disease. The homeopathy may be an alternative way of control, by inducing plant resistance. This study aimed to evaluate the influence of the homeopathic product Cina at dynamizations 12, 24, 50, 100, 200, and 400 CH (centesimal hahnemanian dilutions) on the number of root ...

  18. Integrated application of some compatible biocontrol agents along with mustard oil seed cake and furadan on Meloidogyne incognita infecting tomato plants

    Goswami, Bijoy Kumar; Pandey, Rajesh Kumar; Rathour, Kabindra Singh; Bhattacharya, Chaitali; Singh, Lokendra

    2006-01-01

    Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents viz., Paecilomyces lilacinus and Trichoderma viride alone or in combination with mustard cake and furadan promoted plant growth, reduced number of galls/plant, egg masses/root system and eggs/egg mass. The fungal bioagents along with mustard cake and nematicide showed least nemat...

  19. Virtual screening and in vitro assay of potential drug like inhibitors from spices against Glutathione-S-Transferase of Meloidogyne incognita

    Babu, Rosana O; Moorkoth, Dinsha; Azeez, Shamina; Eapen, Santhosh J

    2012-01-01

    Glutathione S-transferases (GSTs) enzymes are critical antioxidant and detoxification system responsible for long-term existence of nematodes in host species. Hence, 16 phytochemicals predicted and reported to have potential nematicidal activity have been docked to GST enzyme of Meloidogyne incognita to assess their binding affinity and inhibitory activity. In vitro effects of these phytochemicals from in silico results have been done for validation of docking studies and efficacy in...

  20. BEHAVIOR OF GUAVA MATERIALS (Psidiumguajava LINNEO ON THE THE ROOT KNOT NEMATODE [Meloidogyne incognita (KOFOID & WHITE CHITWOOD AND Meloidogyne javanica (TREUB CHITWOOD] PARASITISM / COMPORTAMIENTO DE MATERIALES DE GUAYABO (Psidium guajava LINNEO AL PARASITISMO DEL NEMATODO FORMADOR DE AGALLAS [Meloidogyne incognita (KOFOID & WHITE CHITWOOD Y Meloidogyne javanica (TREUB CHITWOOD

    ALEJANDRA DUQUE ARISTIZÁBAL

    2013-12-01

    Full Text Available Guava roots are parasitized by the root knot nematode (Meloidogyne spp., which causes production losses between 30 and 60%. Due to this, the main goal of this research was to evaluate the reaction of four varieties of guava under nursery conditions to the attack of Meloidogyne incognita and M javanica complex. In the Jaibaná Frutales nursery, in the municipality of Pereira (Risaralda, seedlings of four varieties of guava: Guava pear and Common guava (Psidiumguajava, Cas guava (Psidiumfriedrichsthalianum, and Peruvian guava (Psidiumcattleianum, were planted in plastic bags containing soil and rice hull in a 3:1 proportion. Twenty days after planted, 15 seedlings of each variety were inoculated with a mixture of 1,000, 5,000 and 10,000 eggs and Meloidogyne spp juveniles, and their respective controls without inoculation. Seedlings were assigned under a completely randomized design. The Peruvian guava variety with 5.75g and 8.03g roots and aerial parts dry weight respectively, and Cas guava variety with 10.27g and 9.23g roots and aerial parts dry weight, respectively, had the lowest root gall index with 0.1 and 1.1, and Meloidogyne spp. reproduction with values between 75 and 4.575 eggs and juveniles/100g of roots. These varieties were statistically different from the guava Pear variety with 13,96g y 11,33g roots and aerial parts dry weight respectively, and Common guava with 11,35g y 13,9g roots and aerial parts dry weight respectively, which had the highest root gall index with 5 and reproduction with 149.775 eggs and 72.950 juveniles/100g of roots. In conclusion, the Cas and Peruvian varieties were resistant and immune respectively, to Meloidogyne incognita and M. javanica, allowing them to be used as rootstocks or patronages, while guava Pear and Common guava were highly susceptible to both species. RESUMEN: Las raíces del guayabo son parasitadas por el nematodo del nudo radical (Meloidogyne spp., ocasionando pérdidas de la producción entre 30 y 60%. Debido a esto, el principal objetivo de esta investigación fue evaluar en condiciones de almácigo la reacción de cuatro variedades de guayabo al ataque del complejo Meloidogyne incognita y M. javanica. En el vivero Jaibaná Frutales, del municipio de Pereira (Risaralda, plántulas de cuatro variedades: Pera y Común (Psidium guajava, Agrio (Psidium friedrichsthalianum y Peruano (Psidium cattleianum, fueron sembradas en bolsas de plástico que contenían suelo y cascarilla de arroz en proporción 3:1. Veinte días después de sembradas, a 15 plántulas de cada una de las variedades le fueron inoculadas una mezcla de 1.000, 5.000 y 10.000 huevos y juveniles de Meloidogyne, y los respectivos testigos sin inocular. Las plántulas fueron asignadas bajo un diseño experimental completamente aleatorio. Las variedades Peruano con 5,75g y 8,03g de peso seco de raíces y parte aérea, respectivamente, y Agrio con 10,27g y 9,23g de peso seco de raíces y parte aérea, respectivamente, presentaron el menor índice de nudosidad con 0,1 y 1,1, y reproducción de Meloidogyne spp. con valores entre 75 y 4.575 huevos y juveniles/100g de raíces. Estas variedades fueron estadísticamente diferentes a la variedad Pera con 13,96g y 11,33g de peso seco de raíces y parte aérea, respectivamente, y Común con 11,35g y 13,9g de peso seco de raíces y parte aérea, respectivamente, quienes presentaron mayor índice de nudosidad con 5 y reproducción con 149.775 huevos y 72.950 juveniles/100g de raíces. Las variedades Agrio y Peruano fueron resistentes e inmunes, respectivamente, al ataque de Meloidogyne incognita y M. javanica, permitiendo ser utilizadas como portainjertos o patrones; mientras que las variedades Pera y Común fueron altamente susceptibles.

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

    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 sweetpotato breeding program. The experimental setup was a an augmented block design, using three common treatments: the sweetpotato cultivars Brazlândia branca and Palmas, and the nematode-susceptible tomato cultivar Santa Clara. Nematode resistance levels were defined both by the nematode reproduction factor and by the nematode reproduction index relative to tomato cv. Santa Clara. The ratio between genetic and environmental coefficients of variation and the broad-sense heritability estimates were high, for both nematodes reproduction factor and reproduction index, indicating that the selection method deployed was efficient for the selection of resistant genotypes. Fifty-seven sweetpotato clones were identified as resistant to M. incognita race 1, and selected to continue in the sweetpotato breeding program.

  2. Grafted eggplant yield, quality and growth in infested soil with Verticillium dahliae and Meloidogyne incognita Produo, qualidade e crescimento de beringela enxertada, em solo infestado com Verticillium dahliae e Meloidogyne incognita

    Sebahattin rk

    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 produo 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 no infestado. A infestao do solo reduziu a produo, altura da planta, biomassa da parte area, massa mdia dos frutos, massa de matria seca da parte area, conforme a cultivar utilizada e a enxertia. A enxertia reduziu os contedos de cido oxlico e de slidos solveis e aumentou a massa mdia de frutos, conforme a cultivar ou a presena do patgeno no solo. A enxertia tambm reduziu o efeito negativo dos patgenos sobre o ndice de doena, a altura de planta e a massa de matria seca da parte area. A cultivar Pala foi mais vigorosa que a Faselis, e S. torvum foi um porta-enxerto vigoroso. A combinao de porta-enxerto vigoroso com a cultivar fraca (Faselis foi mais adequada que a de porta-enxerto vigoroso e a cultivar vigorosa (Pala. Ouso de S. torvum como porta-enxerto para a cultivar Faselis, em solo infestado, provavelmente promissora na horticultura convencional e na horticultura sustentvel de baixos insumos, pois a enxertia aumenta a proteo contra os patgenos, e reduz a perda de qualidade dos frutos e da produo.

  3. Efeito de exsudatos de cultura de células de plantas em juvenis de segundo estádio de Meloidogyne incognita Effect of exudates of plant cell culture on second-stage juveniles of Meloidogyne incognita

    Fernando S. Rocha

    2004-06-01

    Full Text Available Calus foram obtidos de tomateiro (Lycopersicon esculentum, cafeeiro (Coffea arabica, alfafa (Medicago sativa, orquídea (Dendrobium nobile, mostarda (Brassica rapa, batata doce (Ipomoea batatas, fumo (Nicotiana tabacum, cenoura (Daucus carota e Crotalaria juncea em meio sólido de Murashige & Skoog (MS seguido do cultivo em meio líquido MS em temperatura de 25-28 ºC. Após um mês, a suspensão foi passada em membrana Millipore 0,22 µm, obtendo-se, assim, o exsudato da cultura de células de cada planta testada. Ovos ou juvenis de segundo estádio (J2 de Meloidogyne incognita foram incubados nesses exsudatos e avaliadas as percentagens de eclosão, mobilidade e mortalidade dos J2. Com exceção dos ovos incubados em exsudato de orquídea, todos os demais inibiram a eclosão quando comparados com a incubação em água (testemunha. Entretanto, nos exsudatos de L. esculentum, cafeeiro e C. juncea a inibição foi mais drástica, semelhante ao aldicarb, mas significativamente diferente e menor do que em soluções contendo ingredientes do meio MS (1-5. Todos os exsudatos reduziram a mobilidade e aumentaram a mortalidade, com maior intensidade em 24 h de exposição. Porém, maior redução na mobilidade ocorreu nos exsudatos de tomateiro e alfafa, enquanto maior mortalidade no exsudato de tomateiro, seguido pelo de mostarda.Callus of Lycopersicon esculentum, Coffea arabica, Medicago sativa, Dendrobium nobile, Brassica rapa, Ipomoea batatas, Nicotiana tabacum, Daucus carota and Crotalaria juncea were obtained in Murashige & Skoog (MS solid medium followed by cell cultivation in MS liquid medium at temperature varying from 25-28 ºC. After one month, the cell suspension was passed through a 0,22 µm Millipore membrane, and the resulting liquid was the cell exudate from each of the tested plants. Eggs or second-stage juveniles (J2 of Meloidogyne incognita were then incubated in these exudates and hatching, mobility and mortality percentages of the J2 were evaluated. Except for the eggs incubated in the exudate of orchid, all the exudates inhibited J2 hatching when compared with incubation in water (control. However, in L. esculentum, C. arabica and C. juncea exudates the inhibition was greatest, similar to aldicar, but significantly less and different than that found in solution of culture medium ingredients MS (1-5. All exudates reduced mobility and increased mortality of M. incognita J2, although theses were enhanced when exposed for 24 h. The greatest reduction of mobility occurred with the exudates of tomato and M. sativa, while greatest mortality occurred with the exudate of L. esculentum, followed by B. rapa.

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

    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 (1.35x105 cfu/g soil) than Vc-2M (9.25x104 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

  5. Virtual screening and in vitro assay of potential drug like inhibitors from spices against Glutathione-S-Transferase of Meloidogyne incognita.

    Babu, Rosana O; Moorkoth, Dinsha; Azeez, Shamina; Eapen, Santhosh J

    2012-01-01

    Glutathione S-transferases (GSTs) enzymes are critical antioxidant and detoxification system responsible for long-term existence of nematodes in host species. Hence, 16 phytochemicals predicted and reported to have potential nematicidal activity have been docked to GST enzyme of Meloidogyne incognita to assess their binding affinity and inhibitory activity. In vitro effects of these phytochemicals from in silico results have been done for validation of docking studies and efficacy in GST inhibition of following compounds such as alpha- pinene, alpha- terpineol, beta- caryophyllene, capsaicin, cinnamic acid, citronellol, curcumin, eugenol, geraniol, isoeugenol, linalool, myristicin, neral, NVA (N-vanillylnonanamide), piperine, vanillin have been revealed. Nematode inhibition in vitro bioassay for selected compounds could conclude that maximum mortality was observed with highest concentrations of beta- caryophyllene (78%) followed by eugenol (61.6%), cinnamic acid (55%) and N-vanillylnonanamide (49%). These findings thus suggest that the above phytochemicals could be potentially developed as nematicidal molecules against M. incognita infections. PMID:22553389

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

    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.

  7. Integrated application of some compatible biocontrol agents along with mustard oil seed cake and furadan on Meloidogyne incognita infecting tomato plants.

    Goswami, Bijoy Kumar; Pandey, Rajesh Kumar; Rathour, Kabindra Singh; Bhattacharya, Chaitali; Singh, Lokendra

    2006-11-01

    Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents viz., Paecilomyces lilacinus and Trichoderma viride alone or in combination with mustard cake and furadan promoted plant growth, reduced number of galls/plant, egg masses/root system and eggs/egg mass. The fungal bioagents along with mustard cake and nematicide showed least nematodes reproduction factor as compared to untreated infested soil. PMID:17048300

  8. Assessment of DAPG-producing Pseudomonas fluorescens for Management of Meloidogyne incognita and Fusarium oxysporum on Watermelon

    Meyer, Susan L. F.; Everts, Kathryne L.; Gardener, Brian McSpadden; Masler, Edward P.; Abdelnabby, Hazem M. E.; Skantar, Andrea M.

    2016-01-01

    Pseudomonas fluorescens isolates Clinto 1R, Wayne 1R, and Wood 1R, which produce the antibiotic 2,4-diacetylphloroglucinol (DAPG), can suppress soilborne diseases and promote plant growth. Consequently, these beneficial bacterial isolates were tested on watermelon plants for suppression of Meloidogyne incognita (root-knot nematode: RKN) and Fusarium oxysporum f. sp. niveum (Fon). In a greenhouse trial, Wayne 1R root dip suppressed numbers of RKN eggs per gram root on ‘Charleston Gray’ watermelon by 28.9%. However, in studies focused on ‘Sugar Baby’ watermelon, which is commercially grown in Maryland, a Wayne 1R root dip did not inhibit RKN reproduction or plant death caused by Fon. When all three isolates were applied as seed coats, plant stand in the greenhouse was reduced up to 60% in treatments that included Fon ± P. fluorescens, and eggs per gram root did not differ among treatments. In a microplot trial with Clinto 1R and Wayne 1R root dips, inoculation with P. fluorescens and/or Fon resulted in shorter vine lengths than treatment with either P. fluorescens isolate plus RKN. Root weights, galling indices, eggs per gram root, and second-stage juvenile (J2) numbers in soil were similar among all RKN-inoculated treatments, and fruit production was not affected by treatment. Plant death was high in all treatments. These studies demonstrated that the tested P. fluorescens isolates resulted in some inhibition of vine growth in the field, and were not effective for enhancing plant vigor or suppressing RKN or Fon on watermelon. PMID:27168652

  9. Pathogenicity of Meloidogyne incognita Race 1 on Turmeric (Curcuma longa L. as Influenced by Inoculum Density and Poultry Manure Amendment

    Kevin I. Ugwuoke

    2010-01-01

    Full Text Available A glasshouse experiment was conducted to assess the pathogenicity of Meloidogyne incognita race 1 on turmeric (Curcuma longa L. at three inoculum densities (0, 2500, 5000 eggs plant-1 and soil amendment with different levels of Poultry Manure (PM (0, 10, 20, 30 and 40 t ha-1. The results obtained showed that root-galling and egg production decreased in a linear response to increasing PM level at both low and high inoculum densities (r = -0.88 and r = -0.85, respectively; p=0.01. The lowest gall index and egg mass index of 2.0 were recorded in plants amended with 40 and 30 t ha-1 PM, respectively. The high nematode density was more pathogenic (p=0.05 than the low density. Shoot length, fresh shoot and root weights responded in a curvilinear pattern with increasing levels of PM. In general, these growth variables increased with increase in PM level up to 20 t ha-1 and then declined with further increase. At high inoculum density, shoot growth was enhanced by 242 and 58% with 20 and 40 t ha-1 PM relative to unamended soil, respectively. Conversely, fresh root weight was increased by 120% and reduced by 12.8% with 20 and 40 t ha-1 PM, respectively. From this study, it could be inferred that higher levels of PM were highly nematicidal but phytotoxic to turmeric plants; the optimal rate of PM amendment is predicted to be 18-22 t ha-1. However, for this method to be incorporated into Integrated Nematode Management Programme of turmeric, field trials are needed for the optimization of the quantity, time and method of application.

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

    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.

  11. Evidence of differences between the communities of arbuscular mycorrhizal fungi colonizing galls and roots of Prunus persica infected by the root-knot nematode Meloidogyne incognita.

    Alguacil, Maria del Mar; Torrecillas, Emma; Lozano, Zenaida; Roldán, Antonio

    2011-12-01

    Arbuscular mycorrhizal fungi (AMF) play important roles as plant protection agents, reducing or suppressing nematode colonization. However, it has never been investigated whether the galls produced in roots by nematode infection are colonized by AMF. This study tested whether galls produced by Meloidogyne incognita infection in Prunus persica roots are colonized by AMF. We also determined the changes in AMF composition and biodiversity mediated by infection with this root-knot nematode. DNA from galls and roots of plants infected by M. incognita and from roots of noninfected plants was extracted, amplified, cloned, and sequenced using AMF-specific primers. Phylogenetic analysis using the small-subunit (SSU) ribosomal DNA (rDNA) data set revealed 22 different AMF sequence types (17 Glomus sequence types, 3 Paraglomus sequence types, 1 Scutellospora sequence type, and 1 Acaulospora sequence type). The highest AMF diversity was found in uninfected roots, followed by infected roots and galls. This study indicates that the galls produced in P. persica roots due to infection with M. incognita were colonized extensively by a community of AMF, belonging to the families Paraglomeraceae and Glomeraceae, that was different from the community detected in roots. Although the function of the AMF in the galls is still unknown, we hypothesize that they act as protection agents against opportunistic pathogens. PMID:21984233

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

    2016-01-01

    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. PMID:27144277

  13. Descripción morfológica de selecciones de Psidium guajava L. tolerantes y Psidium friedrichsthalianum (Berg.) Nied resistente a Meloidogyne incognita en el estado Zulia, Venezuela Morphological description of selections of Psidium guajava L. tolerants and Psidium friedrichsthalianum (Berg.) Nied resistant to Meloidogyne incognita in Zulia state, Venezuela

    Molero, T.; Molina, J.; A Casassa-Padrón

    2003-01-01

    Con el objetivo de realizar una descripción morfológica se escogieron siete selecciones de P. guajava tolerantes, una susceptible y una de P. friedrichsthalianum "Cas" resistente al nematodo Meloidogyne incognita, ubicadas en el Centro Frutícola del Zulia-CORPOZULIA, municipio Mara, estado Zulia, Venezuela. Se recolectaron hojas, flores y frutos y se evaluó forma, margen, color, longitud del pecíolo, ancho y longitud de las hojas, relación ancho por longitud, número de nervaduras, tamaño de l...

  14. The role of betaines in alkaline extracts of Ascophyllum nodosum in the reduction of Meloidogyne javanica and M. incognita infestations of tomato plants

    Wu, Y.; Jenkins, T.; Blunden, G.; Whapham, C.; Hankins, S.D.

    1997-01-01

    L'application sur les racines de plants de tomates d'un extrait alcalin de l'algue brune #Ascophyllum nodosum$, disponible dans le commerce, produit une réduction significative du nombre de juvéniles de deuxième stade de #Meloidogyne javanica$ et #M. incognita$ pénétrant dans les racines, en comparaison avec des plants de tomates traités uniquement avec de l'eau. Le nombre d'oeufs récupérés sur les plants traités par l'extrait d'algue est également significativement plus faible. Lorsque les t...

  15. Separate and Combined Effects of Fusarium oxysporum f. sp. tracheiphilum and Meloidogyne incognita on Growth and Yield of Cowpea (Vigna unguiculata L. Walp Var. Moussa-Local

    A.O. Ogaraku

    2008-01-01

    Full Text Available A study was undertaken to determine the separate and combined affects of Fusarium oxysporum f. sp. tracheiphilum and Meloidogyne incognita on growth and yield of cowpea variety Moussa-local. It was observed that growth and yield components of the cowpea were generally reduced in all treatments as compared to that of control. Single infection with only nematode caused more growth and yield reductions than infection with only fungus. Reduction in the growth and yield components were generally higher in simultaneous infection than infection with either of the pathogens. Growth and yield reduction in combined infection did not vary significantly from those caused by successive infection where either of the pathogens was made to precede the other. Infection with both pathogens caused significant increases in the root galls, number of eggs and juveniles when compared with infection with nematode only.

  16. Eclosão de Meloidogyne incognita, M. javanica e M. mayaguensis em lixiviados de caupi associado a Glomus etunicatum e Bradyrhizobium sp

    Siqueira Kércya M. S.

    2004-01-01

    Full Text Available O objetivo do presente estudo foi avaliar a influência de lixiviados de caupi (Vigna unguiculata cultivar Epace 10 inoculada com Glomus etunicatum e/ou Bradyrhizobium sp. sobre eclosão de Meloidogyne incognita, M. javanica e M. mayaguensis. O solo foi infestado com 200 esporos do fungo micorrízico e/ou 1 ml de suspensão contendo 10(8 UFC/ml das estirpes de Bradyrhizobium NFB 700 e NFB 652, e semeados com caupi, deixando-se plantas não inoculadas como testemunha. As plantas foram mantidas em condições de casa de vegetação, durante 57 dias após infestação, para coleta dos lixiviados. Procederam-se avaliações após 0, 24, 48 e 144 h de imersão de ovos dos nematóides em água ou lixiviados de plantas não inoculadas e inoculadas com fungo e bactéria em conjunto ou isoladamente. O delineamento adotado foi do tipo inteiramente casualizado em arranjo fatorial 3'5'4 (nematóide ' lixiviado ' período de exposição, com quatro repetições. Meloidogyne javanica apresentou maior (P< 0,01 percentual de juvenis eclodidos quando em lixiviados de plantas inoculadas simultaneamente com o fungo e a bactéria. Considerando o tempo de exposição aos lixiviados, M. javanica e M. mayaguensis apresentaram comportamento semelhante, em relação ao percentual de juvenis eclodidos, diferindo ambas de M. incognita, após 144 h. A eclosão de juvenis em função do tempo, em resposta a cada lixiviado, ajustou-se (P< 0,01 ao modelo quadrático.

  17. Knocking-Down Meloidogyne incognita Proteases by Plant-Delivered dsRNA Has Negative Pleiotropic Effect on Nematode Vigor

    Antonino de Souza Júnior, José Dijair; Ramos Coelho, Roberta; Tristan Lourenço, Isabela; da Rocha Fragoso, Rodrigo; Barbosa Viana, Antonio Américo; Lima Pepino de Macedo, Leonardo; Mattar da Silva, Maria Cristina; Gomes Carneiro, Regina Maria; Engler, Gilbert; de Almeida-Engler, Janice; Grossi-de-Sa, Maria Fatima

    2013-01-01

    The root-knot nematode Meloidogyne incognita causes serious damage and yield losses in numerous important crops worldwide. Analysis of the M. incognita genome revealed a vast number of proteases belonging to five different catalytic classes. Several reports indicate that M. incognita proteases could play important roles in nematode parasitism, besides their function in ordinary digestion of giant cell contents for feeding. The precise roles of these proteins during parasitism however are still unknown, making them interesting targets for gene silencing to address protein function. In this study we have knocked-down an aspartic (Mi-asp-1), a serine (Mi-ser-1) and a cysteine protease (Mi-cpl-1) by RNAi interference to get an insight into the function of these enzymes during a host/nematode interaction. Tobacco lines expressing dsRNA for Mi-ser-1 (dsSER), Mi-cpl-1 (dsCPL) and for the three genes together (dsFusion) were generated. Histological analysis of galls did not show clear differences in giant cell morphology. Interestingly, nematodes that infected plants expressing dsRNA for proteases produced a reduced number of eggs. In addition, nematode progeny matured in dsSER plants had reduced success in egg hatching, while progeny resulting from dsCPL and dsFusion plants were less successful to infect wild-type host plants. Quantitative PCR analysis confirmed a reduction in transcripts for Mi-cpl-1 and Mi-ser-1 proteases. Our results indicate that these proteases are possibly involved in different processes throughout nematode development, like nutrition, reproduction and embryogenesis. A better understanding of nematode proteases and their possible role during a plant-nematode interaction might help to develop new tools for phytonematode control. PMID:24392004

  18. Multiyear evaluation of the durability of the resistance conferred by Ma and RMia genes to Meloidogyne incognita in Prunus under controlled conditions.

    Khallouk, Samira; Voisin, Roger; Portier, Ulysse; Polidori, Joël; Van Ghelder, Cyril; Esmenjaud, Daniel

    2013-08-01

    Root-knot nematodes (RKNs) (Meloidogyne spp.) are highly polyphagous pests that parasitize Prunus crops in Mediterranean climates. Breeding for RKN-resistant Prunus cultivars, as an alternative to the now-banned use of nematicides, is a real challenge, because the perennial nature of these trees increases the risk of resistance breakdown. The Ma plum resistance (R) gene, with a complete spectrum, and the RMia peach R gene, with a more restricted spectrum, both provide total control of Meloidogyne incognita, the model parthenogenetic species of the genus and the most important RKN in terms of economic losses. We investigated the durability of the resistance to this nematode conferred by these genes, comparing the results obtained with those for the tomato Mi-1 reference gene. In multiyear experiments, we applied a high and continuous nematode inoculum pressure by cultivating nematode-infested susceptible tomato plants with either Prunus accessions carrying Ma or RMia R genes, or with resistant tomato plants carrying the Mi-1 gene. Suitable conditions for Prunus development were achieved by carrying out the studies in a glasshouse, in controlled conditions allowing a short winter leaf fall and dormancy. We first assessed the plum accession 'P.2175', which is heterozygous for the Ma gene, in two successive 2-year evaluations, for resistance to two M. incognita isolates. Whatever the isolate used, no nematodes reproducing on P.2175 were detected, whereas galls and nematodes reproducing on tomato plants carrying Mi-1 were observed. In a second experiment with the most aggressive isolate, interspecific full-sib material (P.2175 × ['Garfi' almond × 'Nemared' peach]), carrying either Ma or RMia (from Nemared) or both (in the heterozygous state) or neither of these genes, was evaluated for 4 years. No virulent nematodes developed on Prunus spp. carrying R genes, whereas galling and virulent individuals were observed on Mi-1-resistant tomato plants. Thus, the resistance to M. incognita conferred by Ma in Prunus material in both a pure-plum and an interspecific genetic background, or by RMia in an interspecific background, appears to be durable, highlighting the value of these two genes for the creation of Prunus rootstock material. PMID:23425239

  19. 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

    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 reprodução do nematóide. Dos 117 isolados avaliados, foram selecionados inicialmente os isolados endofíticos ENM7, ENM10 e ENM51, todos pertencentes ao gênero Bacillus, que reduziram significativamente a massa de ovos e/ou o índice de galhas. Contudo, quando testados novamente, separadamente ou em misturas, esses isolados não mantiveram a eficiência na redução dessas variáveis e, in vitro, não afetaram a eclosão dos juvenis. Os resultados obtidos evidenciam a inconstância da ação das bactérias endofíticas no controle de M. incognita raça 2 em meloeiro.

  20. 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

    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 pathogens. High temperature occurring during experimental period could have increased the genotype susceptibility to the pathogens.

  1. Efeito da incorporação de sementes trituradas defeijão de porco ao solo sobre o parasitismo de Meloidogyne incognita em tomateiro

    SILVA GILSON S.

    2002-01-01

    Full Text Available Avaliou-se, em condições de casa de vegetação, o efeito da suplementação do solo com sementes trituradas de feijão de porco (Canavalia ensiformis sobre os índices de galhas e de massas de ovos de Meloidogyne incognita raça 1 em tomateiro (Lycopersicon esculentum. O substrato utilizado foi solo autoclavado suplementado com 2,5; 5,0; 7,5 e 10,0 g de sementes trituradas/kg de solo. Solo sem a suplementação serviu como testemunha. Para efeito de comparação, o nematicida Carbofuran foi incluído como tratamento adicional. Controle do nematóide foi obtido a partir da incorporação de 5,0 g de sementes trituradas/kg de solo, sendo o efeito proporcional à dosagem. Os índices de galhas e massas de ovos foram reduzidos em 48% e 64%, respectivamente, com a aplicação de 10 g de sementes trituradas/kg de solo.

  2. Cloning of the gene Lecanicillium psalliotae chitinase Lpchi1 and identification of its potential role in the biocontrol of root-knot nematode Meloidogyne incognita.

    Gan, Zhongwei; Yang, Jinkui; Tao, Nan; Liang, Lianming; Mi, Qili; Li, Juan; Zhang, Ke-Qin

    2007-10-01

    The nematophagous fungus Lecanicillium psalliotae (syn. Verticillium psalliotae) is a well-known biocontrol agent. In this study, a chitinase gene Lpchi1 was isolated for the first time from L. psalliotae using degenerate primers and DNA-walking technique. The cloned gene Lpchi1 encoding 423 amino acid residues shares a high degree of homology with other pathogenicity-related chitinases from entomopathogenic and mycoparasitic fungi. The complementary DNA sequence of the mature chitinase was amplified via reverse transcription polymerase chain reaction and expressed well in Pichia pastoris GS115. Through gel filtration, the recombinant chitinase was purified as a protein of ca. 45 kDa with an optimal activity at pH 7.0 and 37.6 degrees C. The purified chitinase LPCHI1 was found degrading chitinous components of eggs of the root-knot nematode Meloidogyne incognita and significantly influence its development. Moreover, our results also demonstrate that the protease Ver112 and the chitinase LPCHI1 from the same fungus interacted on the egg infection. PMID:17665191

  3. Reaction of vegetables and aromatic plants to Meloidogyne javanica and M. incognita Reação de hortaliças e plantas aromáticas aos nematoides Meloidogyne javanica e M. incognita

    Cláudia Regina Dias-Arieira

    2012-06-01

    Full Text Available For this research we used 15 day-old seedlings which were transplanted to 2 L pots and inoculated with 4,000 nematode eggs plus juveniles (J2. After 60 days, the root systems were removed and the number of galls and eggs evaluated and used to calculate the nematode reproduction factor (RF. The tomato cv. Santa Cruz was used as a susceptible control. The experimental design was completely randomized, with six replications. Averages were compared using the Tukey or Scott-Knott test at 5%. For lettuce, Salad Bowl (Mimosa type, Elizabeth and Elisa (Lisa and Vera cultivars (crisphead, the number of galls and the RF for M. javanica were statistically higher than for the control, whereas, for the other vegetable crops, the highest number of galls and eggs were found in chicory and basil. The highest susceptibility to M. incognita was observed in Mimosa lettuce cv. Salad Bowl, chicory cultivars, parsley cv. Graúda Portuguesa and basil. Marjoram exhibited no M. incognita galls.Para avaliar a reação, mudas com 15 dias de idade foram transplantadas para vasos de 2 L de capacidade e inoculadas com 4.000 ovos e eventuais juvenis (J2 dos nematoides. Decorridos 60 dias, os sistemas radiculares foram retirados e avaliados quanto ao número de galhas e ovos, determinando-se o fator de reprodução (FR dos nematoides nas respectivas plantas. Tomateiro cv. Santa Cruz foi utilizado como testemunha. O experimento foi conduzido em delineamento inteiramente casualizado, com seis repetições, e as médias foram comparadas pelo teste Tukey ou Scott-Knott a 5% de probabilidade. Nas alfaces tipo Mimosa cv. Salad Bowl; nas cultivares do tipo Lisa, Elizabeth e Elisa; e na cultivar Vera (tipo crespa, o número de galhas e o FR de M. javanica foi superior ao observado para a testemunha; enquanto para as demais oleráceas, os maiores números de galhas e ovos foram para as cultivares de chicória e para o manjericão. Maior suscetibilidade a M. incognita foi observada para a alface tipo Mimosa cv. Salad Bowl, para as cultivares de chicória, salsa cv. Graúda Portuguesa e manjericão. Apenas manjerona apresentou número de galhas de M. incognita igual a zero.

  4. influence of some types of Algerian soil on the development of rot-knot nematodes Meloidogyne incognita, M. javanica and M. arenaria (Tylenchida,Meloidogynidae)

    Crops under greenhouses offer the possibility of vegetables production of high added value by focusing on earliness. They help to spread the availability timing of vegetables and fruits in the market throughout the year. However, these crops are subject to numerous attacks entailing heavy losses of yield quantity and quality. The plant parasitic nematodes especially rot-knot nematodes of the genus Meloidogyne are considered dangerous enemies of these cultures. The evolution study of these nematodes in different soil types allows one to compare the migration and movement of these nematodes in sandy soils considered as light soils, in clay soils heavy and intermediate silty clay soils. These soils have also rates of organic matter and a percentage of magnesium and calcium that might provide better conditions to the survival and migration of second stage larvae inoculated at a rate of 650 juveniles per pot of 24 cm in diameter where plants of melon Cucumis melo var. (Charentais) known to be susceptible to Meloidogyne was cultivated. The results for the population development of Meloidogyne, after a growing period of 3 months show an increase in the number of eggs, juvenile stages, inflated, swollen females and males in the 3 types of soil and that independently of clay fraction although clay soil may asphyxiate Meloidogyne. The development of the three species of Meloidogyne studied in these soils, the parameters taken into consideration (index of galls, which were 1.58, 1.75 and 1.5 for the sandy clay and the middle ground soils, vigour index and the evolution of populations of Meloidogyne and roots and soil as well as parameters related to production reveal the adaptation of these root-knot nematodes to the clay and sandy loam soils. At the end of culture, the final populations are important in the soils studied; 2680 for soil S. (sandy), 2272 for soil A (clay) and 2327 for soil I (intermediate) with a multiplication rate almost similar ( 4.12, 3.49 and 3.58 respectively). All these parameters can give one clues about the real possibility of developing root-knot nematodes on all types of soil. These findings may be real on the coastal areas of the southern regions characterized with sandy soils that are most infested, but the infestation potential of interior plains characterized by clay and clay loam are certain if necessary measures are not seriously taken to control them. (author)

  5. Presencia del marcador mi-23 de resistencia a Meloidogyne incognita como apoyo a la caracterización del germoplasma de tomate en Venezuela

    Iris Pérez-Almeida

    2015-04-01

    Full Text Available Especies del género Meloidogyne causan daños económicamente significativos en cultivos como el tomate, induciendo agallas en las raíces y causando amarillamiento en las plantas infestadas. El empleo de cultivares resistentes garantiza una agricultura sostenible y productos de alta calidad. Se planteó el uso del marcador co-dominante Mi-23 ligado al gen de resistencia Mi-1.2, el cual confiere resistencia a Meloidogyne spp. como apoyo a la caracterización de 39 accesiones de germoplasma de tomate del INIA-CENIAP y Lara, incluyendo tomates silvestres Solanum pimpinellifolium y S. lycopersicum locales (tipo Cherry, Perita y Margariteño, poblaciones avanzadas y variedades e híbridos comerciales. El ADN se extrajo siguiendo la metodología del CTAB y las amplificaciones de PCR se realizaron con los cebadores Mi23F/R. Los materiales genéticos formaron tres grupos de acuerdo al patrón de amplificación: 1 la población 9, del INIA-Lara, con un fragmento de 400 pb, como el ADN testigo (proveniente de Belarús; 2 Cherry-Lobatera, Perita Agrovitas, poblaciones 5 y 10, Cherry-189, híbridos Mariana y Salad-F1, con dos fragmentos de 450 y 400 pb; y 3 los restantes 31 materiales, entre ellos, tomates silvestres, cultivares locales, poblaciones avanzadas o promisorias, y variedades e híbridos comerciales, con un fragmento de 450 pb. Los dos primeros grupos se pueden correlacionar con genotipos resistentes homocigotos y heterocigotos, respectivamente, y el último con genotipos susceptibles. La utilización del marcador SCAR Mi-23, ligado al gen Mi-1.2 permitió discriminar las accesiones de tomate del INIA, e identificar ocho de ellas con patrones asociados a genotipos resistentes al nematodo M. incognita, incluyendo tres poblaciones avanzadas del INIA-Lara y una local del INIA-CENIAP.

  6. Reaction of coffee genotypes to different populations of Meloidogyne spp.: detection of a naturally virulent M. exigua population Reao de gentipos de cafeeiro a diferentes populaes de Meloidogyne spp.: deteco de uma populao de M. exigua naturalmente virulenta

    Maria de Ftima S. Muniz

    2009-12-01

    Full Text Available The reaction of seven genotypes of Coffea arabica to 10 Meloidogyne spp. populations collected mainly from coffee plantations in Brazil and Costa Rica was evaluated under greenhouse conditions. The inoculum consisted of 10,000 eggs per plant. Evaluations were done 8 months after inoculations considering the root fresh weight, gall and egg mass indices, number of eggs per gram of root and reproduction factor (RF. The cultivars Obat IAC 1669-20, Sarchimor IAC 4361 and Tupi Amarelo IAC 5111 exhibited susceptibility to the four Brazilian M. exigua populations tested. However, cv. Tupi Vermelho IAC 1669-33 revealed resistance (RF value of 0.7 to the M. exigua population from Lavras, Minas Gerais State, Brazil. A population of M. exigua from Bom Jesus de Itabapoana, Rio de Janeiro State, Brazil, was highly virulent on cv. IAPAR 59 (RF= 165.7, bearing resistance gene Mex-1, and was also virulent on genotype Paraso (H 419-5-4-5-2 (RF=396.2. A Meloidogyne sp. population on coffee from Gara, So Paulo State, Brazil, reproduced at low rates (RF ranging from 0.1 to 3.9 on all genotypes. All tested cultivars were susceptible to M. incognita and M. paranaensis. M. mayaguensis of guava from Paran State, Brazil, reproduced at low rates in all coffee genotypes; however, another population of coffee, from Costa Rica, was more aggressive and showed RF value that ranged from 0.8 to 12.4. Results of this study point for the first time to the ability of a naturally occurring M. exigua population to overcome the resistance conferred by the Mex-1 gene.A reao de sete gentipos de Coffea arabica a 10 populaes de Meloidogyne spp. coletadas principalmente em plantios de caf no Brasil e Costa Rica foi avaliada em casa de vegetao. O inculo consistiu de 10.000 ovos por planta. As avaliaes foram realizadas 8 meses aps as inoculaes considerando-se a massa da matria fresca das razes, ndices de galhas e massas de ovos, nmero de ovos por grama de raiz e fator de reproduo (FR. As cultivares Obat IAC 1669-20, Sarchimor IAC 4361 e Tupi Amarelo IAC 5111 exibiram suscetibilidade s quatro populaes brasileiras de M. exigua. Entretanto, cv. Tupi Vermelho IAC 1669-33 mostrou-se resistente (FR=0,7 a uma populao de M. exigua proveniente de Lavras, MG, Brasil. A populao de M. exigua oriunda de Bom Jesus de Itabapoana, RJ, Brasil foi altamente virulenta cv. IAPAR 59 (FR= 165,7, portadora do gene de resistncia Mex-1 e ao gentipo Paraso (H 419-5-4-5-2 (FR=396,2. A populao de Meloidogyne sp. do cafeeiro, Gara, SP, Brasil, reproduziu-se em baixos nveis (FR = 0,1 - 3,9 sobre todos os gentipos. Todas as cultivares testadas foram suscetveis a M. incognita e M. paranaensis. A reproduo de M. mayaguensis obtida de goiabeira, PR, Brasil, foi baixa (FR = 0,0-1,6, em todos os gentipos. Entretanto, outra populao obtida do cafeeiro na Costa Rica apresentou valores de FR que variaram de 0,8 a 12,4. Os resultados deste trabalho mostraram, pela primeira vez, a capacidade de uma populao de M. exigua obtida em campo de superar a resistncia conferida pelo gene Mex-1.

  7. Purification and identification of metabolites produced by Bacillus cereus and B. subtilis active against Meloidogyne exigua, and their in silico interaction with a putative phosphoribosyltransferase from M. incognita

    DENILSON F., OLIVEIRA; HELVCIO M. DOS, SANTOS JNIOR; ALEXANDRO S., NUNES; VICENTE P., CAMPOS; RENATA S.C. DE, PINHO; GIOVANNA C., GAJO.

    2014-06-01

    Full Text Available Com o objetivo de contribuir para o desenvolvimento de produtos para o controle de Meloidogyne exigua, as bactrias Bacillus cereus e B. subtilis foram cultivadas em meio lquido de cultura para produzirem metablitos ativos contra este nematoide parasita de plantas. Os fracionamentos dos extratos e [...] m diclorometano dos meios de cultura produziram uracila, 9H-purina e di-idrouracila. Todos os compostos foram ativos contra M. exigua, sendo o ltimo o mais eficiente. Ele apresentou CL50 de 204 g/mL contra o nematoide, enquanto uma CL50 de 260 g/mL foi observada para o nematicida comercial carbofuran. Uma busca por complexos protena-ligante nos quais o ligante fosse estruturalmente similar di-idrouracila resultou na seleo de fosforibosiltransferases, cujas sequncias foram utilizadas em uma busca in silico no genoma de M. incognita por sequncia de aminocidos semelhante. A sequncia resultante foi modelada e di-idrouracila e 9H-purina foram inseridos nos stios ativos desta provvel fosforibosiltransferase, resultando em complexos protena-ligante que foram submetidos a simulaes por dinmica molecular. Clculos das energias livres de ligao destes complexos revelaram que a constante de dissociao de di-idrouracila e 9H-purina da enzima da ordem de 8,3 x 10-7 e 1,6 x 10-6 M, respectivamente. Consequentemente, estas substncias e a provvel fosforibosiltransferase podem ser de grande utilidade para o desenvolvimento de novos produtos para o controle de M. exigua. Abstract in english To contribute to the development of products to control Meloidogyne exigua, the bacteria Bacillus cereus and B. subtilis were cultivated in liquid medium to produce metabolites active against this plant-parasitic nematode. Fractionation of the crude dichloromethane extracts obtained from the culture [...] s afforded uracil, 9H-purine and dihydrouracil. All compounds were active against M. exigua, the latter being the most efficient. This substance presented a LC50 of 204 g/mL against the nematode, while a LC50 of 260 g/mL was observed for the commercial nematicide carbofuran. A search for protein-ligand complexes in which the ligands were structurally similar to dihydrouracil resulted in the selection of phosphoribosyltransferases, the sequences of which were used in an in silico search in the genome of M. incognita for a similar sequence of amino acids. The resulting sequence was modelled and dihydrouracil and 9H-purine were inserted in the active site of this putative phosphoribosyltransferase resulting in protein-ligand complexes that underwent molecular dynamics simulations. Calculation of the binding free-energies of these complexes revealed that the dissociation constant of dihydrouracil and 9H-purine to this protein is around 8.3 x 10-7 and 1.6 x 10-6 M, respectively. Consequently, these substances and the putative phosphoribosyltransferase are promising for the development of new products to control M. exigua.

  8. Efeito do armazenamento na energia corporal de juvenis do segundo estádio de Meloidogyne incognita infestados por Pasteuria penetrans Effect of storage on body energy of second stage juveniles of Meloidogyne incognita infested by Pasteuria penetrans

    Fernando da Silva Rocha

    2009-02-01

    Full Text Available Neste trabalho, objetivou-se estudar o efeito do período de armazenamento no teor de lipídios de juvenis do segundo estádio (J2 de M. incognita com endósporos de P. penetrans na infectividade e reprodução em tomateiro. Suspensões de M. incognita contendo ou não endósporos de P. penetrans aderidos à cutícula foram armazenadas por 0, 3, 6, 9 e 12 dias, a 28ºC. Após cada período de estocagem, determinou-se a concentração de lipídios neutros corporais por meio da análise de imagem dos J2 coloridos com o corante "Oil Red O". Em seguida, 1.000 J2 foram inoculados em mudas de tomateiros. Após 28 dias, avaliou-se o número de fêmeas parasitadas, número de endósporos/fêmea, número de galhas, massas de ovos e de ovos/g de raiz. O teor de lipídio dos J2 reduziu-se com o aumento do período de estocagem. Porém, maiores perdas ocorreram nos J2 sem endósporos de P. penetrans. A proporção entre as perdas dos J2 com e sem P. penetrans foi pequena e decrescente com o período de estocagem. Entretanto, a desproporção foi grande entre 3 e 6 dias de armazenamento dos J2 com e sem P. penetrans com relação aos parâmetros reprodução e número de galhas, indicando consumo de fontes alternativas ao lipí dio neutro de energia p elo J2 parasitado. Mas o período de armazenamento sempre reduziu a reprodução e número de galhas formadas em tomateiros por J2 com e sem P. penetrans. A perda dessas fontes de energia, ao que tudo indica, leva muitos J2 a morrer antes de chegar ao estádio adulto, pois o número de fêmeas parasitadas reduz-se com o armazenamento, além de propiciar menor produção de endósporos por fêmea. O J2 parasitado por P. penetrans necessita encontrar rapidamente a raiz e não permanecer no solo por mais de 6 dias antes de parasitar a planta.This work aimed to study the effect of storage period on lipid content of second stage juveniles (J2 of M. incognita with endospores of P. penetrans on infectivity and reproduction in tomato. Suspensions of M. incognita containing or not endospores of P. penetrans adhered to cuticle were stored by 0, 3, 6, 9 and 12 days at 28ºC. After each storage period, the concentration of neutral lipids in the body of J2 was determined by image analysis of J2 stained with "Oil Red O". After that, 1.000 J2 were inoculated in tomato seedlings. After 28 days, the number of infected females, number of endospores per females, number of galls, number of egg masses and number of eggs per gram of root were evaluated. The lipid content of J2 reduced with the increase of storage period. However, greater lost occurred on J2 without endospores of P. penetrans. The ratio between J2 lipid losses with and without P. penetrans was small and decreased with storage period. However, the ratio between J2 with and without P. penetrans was greatest between 3 and 6 days of storage in relation to parameters reproduction and number of galls, indicating consumption of alternative energy sources others than neutral lipids by infected J2. But the storage period always reduced the reproduction and number of galls formed in tomatoes by J2 with and without P. penetrans. The loss of those energy sources indicate that many J2 dye before adult stage, because the number of parasitized females reduced with storage, besides of smaller endospores production per female. The J2 infested by P. penetrans needs to find the root quickly and should not stay in the soil for more than 6 days before parasitizing the plant.

  9. Microbiological evaluation and pathogenicity of a liquid bioformulation of the fungus Purpureocillium sp. (strain UdeA 0109) on Meloidogyne incognita-javanica stages / Microbiological evaluation and pathogenicity of a liquid bioformulation of the fungus Purpureocillium sp. (strain UdeA 0109) on Meloidogyne incognita-javanica stages

    Nadya, Lorena Cardona; David, Andrs Borrego; Erika, Pamela Fernndez; Jessika, Snchez; Valentina, Cardona; Gabriel, Montoya.

    2014-09-01

    Full Text Available El Grupo de Biocontrol y Microbiologa Ambiental (BIOMA) cuenta con una formulacin industrial lquida del hongo Purpureocillium sp. (cepa UdeA 0109), desarrollada de conjunto con la casa comercial Laverlam S.A. (Cali, Colombia). En la presente investigacin se evaluaron la viabilidad y la pureza de [...] l producto a diferentes temperaturas de almacenamiento, as como el potencial biocontrolador in vitro y en condiciones de invernadero. Los resultados de viabilidad mostraron cmo las estructuras infectivas no se afectaron por los tiempos de evaluacin ni por las temperaturas de almacenamiento. Los estudios tambin mostraron cmo la pureza del bioformulado bajo las mismas condiciones, se mantuvo por encima del 99 %, y adems se corrobor su patogenicidad in vitro con una CL50 de 104 conidias/mL. Las evaluaciones en invernadero demostraron la propiedad de afectacin de los huevos del complejo Meloidogyne incognita-javanica as como la disminucin de los estadios jvenes con una concentracin de 108 conidias/mL en tres pruebas, con distintas aplicaciones y tiempos de aplicacin. Abstract in english The BIOMA research group (Biocontrol and environmental microbiology) has an industrial liquid formulation based on Purpureocillium sp. (UdeA 0109 strain), developed with the collaboration of Laverlam S.A, a Colombian (Cali) commercial house. In the present study the researchers tested the viability [...] and the purity at different storage temperatures as well as its biological potential both in vitro and under greenhouse conditions. The results of viability showed how the infective structures were affected neither by the evaluation time nor by the storage temperatures. Studies also showed that the purity of the bioformulation in the same conditions was over 99 %, and its pathogenicity in vitro with an LC50 of 104 conidia/mL was corroborated. The greenhouse tests showed the ability to produce damages in eggs of the Meloidogyne incognita-javanica complex, and a decreasing of the J2 stages at a concentration of 108 conidia/mL in three tests performed with a different number of applications and at different times each.

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

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

    2010-01-01

    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 pru...

  11. Interaction of Concurrent Populations of Meloidogyne partityla and Mesocriconema xenoplax on Pecan

    Nyczepir, A.P.; Wood, B. W.

    2008-01-01

    The effect of the interaction between Meloidogyne partityla and Mesocriconema xenoplax on nematode reproduction and vegetative growth of Carya illinoinensis ‘Desirable’ pecan was studied in field microplots. Meloidogyne partityla suppressed reproduction of M. xenoplax, whereas the presence of M. xenoplax did not affect the population density of M. partityla second-stage juveniles in soil. Above-ground tree growth, as measured by trunk diameter 32 months following inoculation, was reduced in t...

  12. Efecto del filtrado crudo de Purpureocillium sp. (Cepa UdeA0106), sobre la eclosin de huevos y movilidad de juveniles de Meloidogyne incognita-javanica / Effect of the raw filtrate of Purpureocillium sp. (UdeA0106 strain) on the eclosion of eggs and the motility of Meloidogyne incognitajavanica juveniles

    Nadya Lorena, Cardona Bustos; Harold, Pavas; Erika Pamela, Fernndez.

    2014-12-01

    Full Text Available Meloidogyne incognita-javanica representa una limitacin de los cultivos agrcolas y es necesario buscar alternativas para su manejo. El presente trabajo tuvo como objetivo evaluar el efecto in vitro del filtrado crudo de Purpureocillium sp. (Cepa UdeA0106) sobre laeclosin de huevos y los estadios [...] juveniles de Meloidogyne spp. Adicionalmente, se evaluaron los medios: caldo extracto de malta (CEM), caldo extracto de levadura (CEL) y caldo papa glucosa (CPG), escogindose aquel que no ejerciera dao sobre la morfologa de los huevos y permitiera la eclosin de los estadios juveniles. El hongo se multiplic durante 7 das y fue filtrado. Para establecer su efecto sobre los huevos y estadios J2 de Meloidogyne spp., se probaron concentraciones del filtrado al 100 %, 90 %, 70 %, 50 %, 25 % y 10 %; comparndolas con un control compuesto de estadios J2 en agua destilada estril (ADE) y CPG. Las variables a evaluar fueron el porcentaje de eclosin e inmovilidad en los J2. La unidad experimental fue la caja de Petri, cada una con 200 huevos/J2, con 5 rplicas de cada tratamiento. Se utiliz un diseo experimental completamente aleatorizado con ANOVA (P = 0,05) y anlisis de comparacin mltiple de Tukey. Se encontraron diferencias significativas entre todos los tratamientos (P Abstract in english Meloidogyne incognita-javanica represents an important threat to the agricultural crops, and it is necessary to seek alternatives for its control. The aim of this research it was to evaluate a crude filtrate from the strain Purpureocillium sp. UdeA0106 in order to establish the in vitro effect on th [...] e egg hatching and the immobility of juvenile stages of Meloidogyne spp. The mediums evaluated were malt extract broth (MEB), yeast extract broth (YEB), and potato dextrose broth (PDB), after which it was chosen the one that didn't produce any damages on nematode eggs and allowed the emergence of the larval stages. The fungus was multiplied for 7 days, and then it was filtrated. To evaluate its effect on the eggs and the J2 of Meloidogyne spp., filtrate concentrations were made at 100 %, 90 %, 70 %, 50 %, 25 % and 10 %, contrasting them with a control composed of the J2 stages in sterile distilled water and PDB. The variables evaluated were the percentage of altered eggs and the immobility observed in J2 stages. The experimental unit was the Petri dish, each one containing 200 eggs /J2. Each treatment was replicated 5 times. It was used a completely randomized design, and an ANOVA was performed (P = 0,05) as well as a multiple comparison test (Tukey). Significant differences were found between all treatments (P

  13. Integrated Management of Meloidogyne incognita Infecting Soybean by Certain Organic Amendments, Bacillus thuringiensis, Trichoderma harzianum and Oxamyl with Reference to NPK and Total Chlorophyll Statuus

    A.G. El-Sherif

    2009-01-01

    Full Text Available The integrated control of M. incognita infecting soybean cv. Giza 21 using camel manure, dried leaf powder of marigold, Trichoderma harzianum 100% filtrate, Bacillus thringiensis singly or in combination with oxamyl under greenhouse condition (22±3°C indicated that the concomitant treatments obviously gave better results than single ones did. Moreover, B. thringiensis plus oxamyl at half dose each surpassed all other tested materials in percentage increase of total plant fresh and shoot dry weights (99 and 88 %, respectively, followed by T. harzianum filtrate plus oxamyl (95 and 61% in this respect. On the other hand, pots received T. harzianum filtrate plus oxamyl ranked first in suppressing final nematode population (90%, root galling (65% and eggmass numbers (62.79%, followed by B.t. plus oxamyl, marigold powder +oxamyl and then camel manure + oxamyl, where their reduction percentage values amounted to 88.7, 62.5 and 61%; 88.5, 59.87 and 58.9% and 67, 50.5 and 52.97%, respectively. Of the tested singly applications, T. harzianum filtrate showed the best results in improving plant growth and suppressing nematode development criteria, followed by B.t., whereas, marigold powder and camel manure achieved the lowest values in this respect comparing to nematode alone. Regarding the N, P and K concentrations in leaves of soybean plants inoculated with M. incognita treated with certain organic matters or fungal filtrate or bacterium alone or mixed with oxamyl, they were obviously enhanced by all tested materials whereas the opposite results was recorded for total chlorophyll content comparing to nematode alone.

  14. 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.

    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 7days 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 7days 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. PMID:26545953

  15. Efeito de exsudatos radiculares em endósporos de Pasteuria penetrans e em juvenis do segundo estádio de Meloidogyne incognita Effect of root exudates on endospores of Pasteuria penetrans and on second-stage juvenile of Meloidogyne incognita

    Fernando da Silva Rocha

    2004-12-01

    Full Text Available Juvenis do segundo estádio (J2 de Meloidogyne incognita foram incubados nos exsudatos radiculares de soja (Glycine max, tomateiro (Lycopersicon esculentum, cafeeiro (Coffea arabica, feijoeiro (Phaseolus vulgaris, mostarda (Brassica rapa, Crotalaria juncea e C. spectabilis e em água por 12 h. Em seguida, realizou-se o teste de adesão por centrifugação ou por borbulhamento. Em outro ensaio, endósporos de Pasteuria penetrans foram incubados por quatro dias a 26 ºC nos exsudatos e submetidos à adesão em J2 de M. incognita, sob borbulhamento constante por 24 h em tubos contendo água. Os J2 com endósporos aderidos pelo teste de borbulhamento foram inoculados em mudas de tomateiro. Verificou-se que a incubação dos J2 por 12 h nos exsudatos radiculares testados reduziu o número de endósporos de P. penetrans por J2 independentemente do método de adesão empregado. Os J2 incubados nos exsudatos radiculares testados proporcionaram menor número de fêmeas parasitadas em tomateiro em relação à testemunha (água, bem como menor número de galhas com exceção dos J2 incubados em exsudato do próprio tomateiro. A reprodução dos J2 incubados nos exsudatos radiculares não foi afetada quando comparada à testemunha. A incubação dos endósporos nos exsudatos das plantas testadas reduziu a adesão e a infetividade em J2, em relação à testemunha. Após 28 dias da inoculação, observou-se redução no número de fêmeas parasitadas resultantes da infecção desses J2 com endósporos incubados em exsudatos radiculares comparada com aqueles incubados em água. O parasitismo do J2 com endósporos tratados com exsudatos radiculares e a reprodutividade de fêmeas oriundas da infetividade desses J2 foram semelhantes aos incubados em água.In one assay, second stage juveniles (J2 of Meloidogyne incognita were incubated in root exudates of soybean (Glycine max, tomato (Lycopersicon esculentum, coffee (Coffea arabica, bean (Phaseolus vulgaris, mustard (Brassica rapa, Crotalaria juncea and C. spectabilis and in water for 12 h, followed by endospores adhesion by centrifugation or by air bubbling. In another assay, endospores of Pasterius penetrans were incubated for four days at 26 ºC in the exudates and submitted to adhesion on J2 of M. incognita by constant air bubbling for 24 h in tubes containing water. The J2 with endospore adhesion by air bubbling were inoculated in tomato seedlings. The incubation of J2 for 12 h in the root exudates reduced the number of P. penetrans endospore per J2, regardless of the adhesion test used, and resulted in fewer parasitized females when compared with the control, as well as a lower number of galls, except in the J2 incubated in exudate of tomato. The reproduction of incubated J2 in the root exudates was not affected when compared to the control. The endospore incubation in the exudates of the tested plants reduced the adhesion and the infectivity of these endospores to J2 in relation to the control. After 28 days from inoculation, reduction was observed in the number of parasitized females resulting from infection of those J2 with endospore incubated in exudates when compared with those incubated in water. The parasitism of J2 with endospore treated with exudates and the reproduction of infected J2 females were similar to those incubated in water.

  16. Efecto del filtrado crudo de Purpureocillium sp. (Cepa UdeA0106, sobre la eclosión de huevos y movilidad de juveniles de Meloidogyne incognita-javanica

    Nadya Lorena Cardona Bustos; M.Sc., Ph.D.

    2014-12-01

    Full Text Available Meloidogyne incognita-javanica represents an important threat to the agricultural crops, and it is necessary to seek alternatives for its control. The aim of this research it was to evaluate a crude filtrate from the strain Purpureocillium sp. UdeA0106 in order to establish the in vitro effect on the egg hatching and the immobility of juvenile stages of Meloidogyne spp. The mediums evaluated were malt extract broth (MEB, yeast extract broth (YEB, and potato dextrose broth (PDB, after which it was chosen the one that didn’t produce any damages on nematode eggs and allowed the emergence of the larval stages. The fungus was multiplied for 7 days, and then it was filtrated. To evaluate its effect on the eggs and the J2 of Meloidogyne spp., filtrate concentrations were made at 100 %, 90 %, 70 %, 50 %, 25 % and 10 %, contrasting them with a control composed of the J2 stages in sterile distilled water and PDB. The variables evaluated were the percentage of altered eggs and the immobility observed in J2 stages. The experimental unit was the Petri dish, each one containing 200 eggs /J2. Each treatment was replicated 5 times. It was used a completely randomized design, and an ANOVA was performed (P = 0,05 as well as a multiple comparison test (Tukey. Significant differences were found between all treatments (P < 0,05, although the most effective in inhibiting both egg hatching and J2 mobility (96,8 % were the full strength filtering (100 %. The dilutions at 90 % and 70 %, were able to produce effects with high percentages in the immobility.

  17. Isolamento e avaliação da atividade nematicida de constituintes químicos de Mucuna cinerea contra Meloidogyne incognita e Heterodera glycines

    Demuner Antonio Jacinto

    2003-01-01

    Full Text Available Phytochemical investigation of the aerial parts and roots of Mucuna cinerea led to the isolation of a mixture of fatty acids, triacylglicerols, beta-sitosterol, stigmasterol, stigmasterol glucoside, daucosterol, asperglaucide (4 and the isoflavonoids prunetin (1, genistein (2, medicarpin (3, daidzein (5, 7-O-alpha-glycopiranosyl daidzein (6. An in vitro bioassay was carried out with compounds 1-4, at the concentration of 50 and 5 mug mL-1 against the phytonematodes M. incognita and H. glycines. Although the four compounds showed some nematocidal property, the most active was (1, causing 70% mortality of M. incognita at the concentration of 50 mug mL-1.

  18. Development of Four Populations of Meloidogyne hapla on Two Cultivars, of Cucumber at Different Temperatures

    Stephan, Z.A.; Trudgill, D. L.

    1982-01-01

    The infectivity and development of four populations of Meloidogyne hapla were compared, at three temperatures, on tomato and two varieties of cucumber. A population from Canada produced few root-galls on cucumber and, except at 24 C, no larvae developed into adult females and produced egg masses. In contrast, a population with 45 chromosomes from America produced many galls on cucumber and small proportions of larvae became females and produced egg masses at 20 and 24 C. At 18 C this populati...

  19. Isolamento e avaliação da atividade nematicida de constituintes químicos de Mucuna cinerea contra Meloidogyne incognita e Heterodera glycines

    Demuner Antonio Jacinto; Barbosa Luiz Cláudio de Almeida; Nascimento Jeferson Chagas do; Vieira Jessy James; Santos Maria Amelia dos

    2003-01-01

    Phytochemical investigation of the aerial parts and roots of Mucuna cinerea led to the isolation of a mixture of fatty acids, triacylglicerols, beta-sitosterol, stigmasterol, stigmasterol glucoside, daucosterol, asperglaucide (4) and the isoflavonoids prunetin (1), genistein (2), medicarpin (3), daidzein (5), 7-O-alpha-glycopiranosyl daidzein (6). An in vitro bioassay was carried out with compounds 1-4, at the concentration of 50 and 5 mug mL-1 against the phytonematodes M. incognita and H. g...

  20. Pathological Reaction of Crested Wheatgrass Cultivars to Four Meloidogyne chitwoodi Populations

    Griffin, G. D.; Asay, K. H.

    1989-01-01

    Meloidogyne chitwoodi populations from Tulelake, California; Ft. Hall, Idaho; Beryl, Utah; and Prosser, Washington, significantly (P < 0.05) reduced dry shoot weights of crested wheatgrass (Agropyron cristatum L., Gaertn. and A. desertorum, Fisch. ex Link, Schult.) cultivars Hycrest, Fairway, and Nordan in experiments conducted in a greenhouse and growth chamber. Shoot growth depression, root galling, and nematode reproduction indices were greatest (P < 0.05) on plants inoculated with 5,000 e...

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

    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-knot nematodes or interfere with hatching and affect their capacity to invade and develop within their roots. M. pruriens, C. spectabilis and C. retusa could be used with effect to decrease a mixed field populations of root-knot nematodes. PMID:22736854

  2. Beneficial effects of Enterobacter cloacae and Pseudomonas mendocina for biocontrol of Meloidogyne incognita with the endospore-forming bacterium Pasteuria penetrans

    Duponnois, Robin; Bâ, A.M.; Mateille, Thierry

    1999-01-01

    Deux bactéries rhizosphériques, #Enterobacter cloacae$ et #Pseudomonas mendocina$, ont été isolées à partir de la rhizosphère de plants de tomate prélevés dans un sol très infesté par des nématodes à galles et l'antinomycète #Pasteuria penetrans$. Les deux souches bactériennes ont stimulé la croissance de la plante, inhibé le développement du nématode #Meloidogyne incongita$ et augmenté in vitro l'attachement des spores de #P. penetrans sur la cuticule des nématodes. #E. cloacae$ a significat...

  3. Isolamento e avaliação da atividade nematicida de constituintes químicos de Mucuna cinerea contra Meloidogyne incognita e Heterodera glycines Isolation and nematocidal activity evaluation of chemical constituents from Mucuna cinerea against Meloidogyne incognita and Heterodera glycines

    Antonio Jacinto Demuner; Luiz Cláudio Almeida Barbosa; Jeferson Chagas do Nascimento; Jessy James Vieira; Maria Amelia dos Santos

    2003-01-01

    Phytochemical investigation of the aerial parts and roots of Mucuna cinerea led to the isolation of a mixture of fatty acids, triacylglicerols, beta-sitosterol, stigmasterol, stigmasterol glucoside, daucosterol, asperglaucide (4) and the isoflavonoids prunetin (1), genistein (2), medicarpin (3), daidzein (5), 7-O-alpha-glycopiranosyl daidzein (6). An in vitro bioassay was carried out with compounds 1-4, at the concentration of 50 and 5 mug mL-1 against the phytonematodes M. incognita and H. g...

  4. Effects of furfural on nematode populations and galling on tomato and pepper

    A commercial formulation of furfural (Multiguard® Protect) was evaluated in greenhouse trials over three seasons for effects on parasitic and beneficial nematode populations in roots and soil, plant growth, and galling on tomato and bell pepper caused by Meloidogyne incognita. ‘Tiny Tim’ tomato (So...

  5. Diversity of Meloidogyne spp. on Musa in Martinique, Guadeloupe, and French Guiana

    Cofcewicz, E. T.; Carneiro, R.M.D.G.; Randig, O.; Chabrier, C.; Qunherv, P.

    2005-01-01

    Ninety-six isolates of Meloidogyne species collected from banana fields from Martinique, Guadeloupe, and French Guiana, were examined using esterase (Est) and malate dehydrogenase (Mdh) phenotypes. Adult females identified as M. arenaria, M. incognita, M. javanica, M. cruciani, M. hispanica, and Meloidogyne sp. showed species-specific phenotypes only for the esterase enzymes. Intraspecific variability among isolates of M. arenaria, M. incognita, and M. javanica was detected using Est and Mdh....

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

    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 Tetsukabuto' and 'Excite Ikki' and four cucumber (Cucumis sativus Japanese type hybrids of ('Yoshinari', 'Kouki', 'Taisho' and 'Tsuyataro'. Two experiments were carried out in greenhouse, each one with a nematode specie. Each plot consisted of one plant per pot containing 2 liters of autoclaved soil. Nine days after the seedlings transplantation, each plant was inoculated with 5,000 eggs and second-stage juveniles (initial population - Pi of M. javanica or M. incognita race 2. 'Rutgers' tomatoes were used as a standard for inoculum viability in both experiments. The experimental design was completely randomized with five replicates per treatment. Sixty days after inoculated, each plant was evaluated, when root fresh weight, total number of nematodes in the soil and in the roots (final population - Pf, nematodes number per gram of root and the reproduction factor of both Meloidogyne species (FR=Pf/Pi were determined. All rootstocks and cucumber hybrids allowed the M. javanica and M. incognita race 2 multiplication, but, generally, reproduction factor values were greater in cucumbers than in rootstocks.

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

    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

  8. DNA characterization and relationship of the genomes of some Meloidogyne species

    Cesium trifluoroacetate (CsTFA) ultracentrifugation method of DNA isolation proved more satisfactory than phenol extraction. The base composition (%GC) of the DNAs of M. incognita, M. javanica, M. arenaria, and M. hapla, as determined by thermal denaturation tests ranged from 31.0 to 32.6% for all the four species. Similarly, the thermal stability covered a narrow range from 82.97 to 83.630C. The relationship of the genomes of twelve populations representing the four Meloidogyne species was measured by binding hybridized DNA by hydroxyapatite. M. incognita, M. javanica, and M. arenaria were found to be closely related to each other, with 80 to 100% DNA homology to labeled 32P-DNA probes prepared from M. incognita and M. arenaria. M. hapla showed wide divergence with 24.5 to 33.5% DNA homology to the probes. One half of the populations showed a slightly higher percent DNA homology with the non-repetitive sequences of the probes, whereas, the other half with the repetitive fraction. The thermal stabilities of the reassociated DNAs indicated differences of 0 to 2.5% in nucleotide base pairs between the populations and the probes

  9. Yield Relationships and Population Dynamics of Meloidogyne spp. on Flue-cured Tobacco

    Barker, K.R.

    1989-01-01

    The complex nature of nematode-induced diseases of tobacco, the relationships between nematode levels and damage, the methods of determining these relationships, and the evolving nematode communities on tobacco in eastern North Carolina are described. Crop damage associated with these pathogens varies with nematode race and species, crop cultivar, microflora, and environmental conditions. Root-gall indices as well as initial and mid-season numbers of Meloidogyne spp, in soil are useful for es...

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

    Vanessa A. Antes; Anna P. Comerlato; Adílson Ricken Schuelter; Regina M.D.G. Carneiro; Cleber Furlanetto

    2012-01-01

    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...

  11. Greenhouse Studies on the Effect of Marigolds (Tagetes spp.) on Four Meloidogyne Species

    Ploeg, Antoon T.

    1999-01-01

    The effects of preplanted marigold on tomato root galling and multiplication of Meloidogyne incognita, M. javanica, M. arenaria, and M. hapla were studied. Marigold cultivars of Tagetes patula, T. erecta, T. signata, and a Tagetes hybrid all reduced galling and numbers of second-stage juveniles in subsequent tomato compared to the tomato-tomato control. All four Meloidogyne spp. reproduced on T. signata 'Tangerine Gem'. Several cultivars of T. patula and T. erecta suppressed galling and repro...

  12. Evaluation of Cover Crops with Potential for Use in Anaerobic Soil Disinfestation (ASD) for Susceptibility to Three Species of Meloidogyne.

    Kokalis-Burelle, Nancy; Butler, David M; Rosskopf, Erin N

    2013-12-01

    Several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on potential use as organic amendments in anaerobic soil disinfestation (ASD) applications. Nematode juvenile (J2) numbers in soil and roots, egg production, and host plant root galling were evaluated on arugula (Eruca sativa, cv. Nemat), cowpea (Vigna unguiculata, cv. Iron & Clay), jack bean (Canavalia ensiformis, cv. Comum), two commercial mixtures of Indian mustard and white mustard (Brassica juncea & Sinapis alba, mixtures Caliente 61 and Caliente 99), pearl millet (Pennisetum glaucum, cv. Tifleaf III), sorghum-sudangrass hybrid (Sorghum bicolor S. bicolor var. sudanense, cv. Sugar Grazer II), and three cultivars of sunflower (Helianthus annuus, cvs. 545A, Nusun 660CL, and Nusun 5672). Tomato (Solanum lycopersicum, cv. Rutgers) was included in all trials as a susceptible host to all three nematode species. The majority of cover crops tested were less susceptible than tomato to M. arenaria, with the exception of jack bean. Sunflower cv. Nusun 5672 had fewer M. arenaria J2 isolated from roots than the other sunflower cultivars, less galling than tomato, and fewer eggs than tomato and sunflower cv. 545A. Several cover crops did not support high populations of M. incognita in roots or exhibit significant galling, although high numbers of M. incognita J2 were isolated from the soil. Arugula, cowpea, and mustard mixture Caliente 99 did not support M. incognita in soil or roots. Jack bean and all three cultivars of sunflower were highly susceptible to M. javanica, and all sunflower cultivars had high numbers of eggs isolated from roots. Sunflower, jack bean, and both mustard mixtures exhibited significant galling in response to M. javanica. Arugula, cowpea, and sorghum-sudangrass consistently had low numbers of all three Meloidogyne species associated with roots and are good selections for use in ASD for root-knot nematode control. The remainder of crops tested had significant levels of galling, J2, and eggs associated with roots, which varied among the Meloidogyne species tested. PMID:24379486

  13. Soil suppressiveness towards Meloidogyne Verticillium or Pythium in greenhouse horticulture

    Wurff, A.W.G., van der; Slooten, M.A., van; Hamelink, R; Bohne, S; Wensveen, W., van

    2011-01-01

    Soils originating from fourteen greenhouse horticultural companies were assessed for the level of suppressiveness of three major pathogens of vegetables and flowers, namely the root knot nematode Meloidogyne incognita, Pythium aphanidermatum and Verticillium dahlia. As controls, three well-documented soils in terms of disease suppressiveness and coarse sand were included for each pathogen. Soils were distributed over three treatments with forty replicates each in a random block design under s...

  14. Diversity and evolution of root-knot nematodes, genus Meloidogyne: new insights from the genomic era.

    Castagnone-Sereno, Philippe; Danchin, Etienne G J; Perfus-Barbeoch, Laetitia; Abad, Pierre

    2013-01-01

    Root-knot nematodes (RKNs) (Meloidogyne spp.) are obligate endoparasites of major worldwide economic importance. They exhibit a wide continuum of variation in their reproductive strategies, ranging from amphimixis to obligatory mitotic parthenogenesis. Molecular phylogenetic studies have highlighted divergence between mitotic and meiotic parthenogenetic RKN species and probable interspecific hybridization as critical steps in their speciation and diversification process. The recent completion of the genomes of two RKNs, Meloidogyne hapla and Meloidogyne incognita, that exhibit striking differences in their mode of reproduction (with and without sex, respectively), their geographic distribution, and their host range has opened the way for deciphering the evolutionary significance of (a)sexual reproduction in these parasites. Accumulating evidence suggests that whole-genome duplication (in M. incognita) and horizontal gene transfers (HGTs) represent major forces that have shaped the genome of current RKN species and may account for the extreme adaptive capacities and parasitic success of these nematodes. PMID:23682915

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

    Silvia Renata S Wilcken; Juliana MO Rosa; Andréa RO Higuti; Maria José de M Garcia; Antonio Ismael Inácio Cardoso

    2010-01-01

    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', '...

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

    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 spearmi...

  17. 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

    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 control with the fungus Paecilomyces lilacinus (Thom., 1910 Samson, 1974 stands out as an advantageous alternative of control, from the ecological or economy points of view. Thus, the objective of this work was to evaluate ten isolates of Paecilomyces lilacinus in the control of Meloidogyne paranaensis in coffee trees (Coffea arabica L. cv. Icatú, in greenhouse conditions. In the first experiment, the coffee seedlings were transplanted to substrate where tomato plants were previously cultivated, for M. paranaensis multiplication. The soil was mixed with 50 g rice colonized with ten isolates of P. lilacinus. In the second experiment, coffee seedlings were transplanted to substrate (1 sand: 1 dirt with 50 g rice colonized with the isolates of P. lilacinus. Then, the seedlings were inoculated with suspension of ±5000 eggs of M. paranaensis. In the two experiments, a new application was made with 50 g of the isolates after fifteen days. The design was completely randomized with twelve treatments and ten replicates. After 90 they days were evaluated. The isolated of P. lilacinus did not affect the diameter of the coffee stalk. In the first experiment, the isolates Pae 22, 24, and 28 promoted the growth of the seedlings, all of the isolates reduced the population of eggs in the root system, and the isolates Pae 3 and 12 reduced the population of J2 of M. paranaensis in the soil. In the second experiment, the isolates Pae 3, 10, 12, and 13 favored the growth of the plants but reduced the weight of the fresh roots, all of the isolates reduced the population of J2 in the soil, and the isolates Pae 3, 10, 13, 18, 22, and 24 reduced the malformations caused by M. paranaensis roots.

  18. First Report of Root-Knot Nematode Meloidogyne enterolobii on Tomato and Cucumber in Switzerland

    Kiewnick, S.; Karssen, G.; Brito, J. A.; Oggenfuss, M.; Frey, J E

    2008-01-01

    Severe stunting and extensive root galling were observed on tomato rootstock (Solanum lycopersicum L. cv. Maxifort) resistant to Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949, M. javanica (Treub, 1885), and M. arenaria (Neal, 1889) Chitwood, 1949 and cucumber (Cucumis sativus L. cv. Loustik) from two commercial greenhouses in the cantons Aargau and Lucerne in northern Switzerland. Examination of the roots of infected plants revealed the presence of root-knot nematodes in large n...

  19. Meloidogyne species in cucurbit crops : characterization and quantification of the host-parasite relationship

    López Gómez, Manuel Francisco

    2015-01-01

    The infection process of Meloidogyne arenaria, M. incognita and M. javanica was compared on zucchini squash, cucumber, melon, pumpkin and watermelon in a growth chamber. All cucurbits were susceptible to the three isolates although M. javanica showed higher invasion rates, faster development and egg production than M. arenaria. Differences among cucurbits were primarily due to root invasion rates and formation of egg masses. Cucumber and melon were better hosts for nematode invasion and repro...

  20. Infection, Reproduction Potential, and Root Galling by Root-knot Nematode Species and Concomitant Populations on Peanut and Tobacco

    Hirunsalee, Anan; Barker, K. R.; Beute, M.K.

    1995-01-01

    Single populations of Meloidogyne arenaria races 1 (MA1) and 2 (MA2) and M. hapla (MH), and mixed populations of MA1 + MA2 and MA1 + MH with four inoculum levels of eggs were tested on peanut cv. 'Florigiant' and M. incognita-resistant tobacco cv. 'McNair 373' in a greenhouse experiment. Root infection, female development, and reproduction of MA2 on peanut and MA1 on resistant tobacco were limited at 2 and 6 weeks. MA1, MH, and MA1 + MH on peanut had similar root infection (total parasitic fo...

  1. Crop Yields and Nematode Population Densities in Triticale-Cotton and Triticale-Soybean Rotations

    Johnson, A.W.; Dowler, C.C.; Baker, S H; Handoo, Z.A.

    1998-01-01

    Triticale cv. Beagle 82, cotton cv. McNair 235, and soybean cv. Twiggs were arranged in three cropping sequences to determine the effects of fenamiphos and cropping sequence on nematode population densities and crop yields under conservation tillage for 4 years. The cropping sequences were triticale (T)-cotton (C)-T-C, T-soybean (S)-T-S, and T-C-T-S. Numbers of Meloidogyne incognita second-stage juveniles declined on trificale but increased on cotton and soybean each year. Root-gall indices o...

  2. Descriptions of Meloidogyne camelliae n.sp. and M. querciana n.sp (Nematoda:Meloidogynidae), with SEM and Host-Range Observations.

    Golden, A M

    1979-04-01

    Meloidogyne camelliae n.sp. on camellia (Camellia japonica) from Japan and M. querciana n.sp. on pin oak (Quercus palustris) from Virginia, USA, are described and illustrated. M. camelliae n.sp. is distingnishable from other species of the genus especially by its striking perineal pattern having heavy ropelike striae forming a squarish to rectangular outline with shoulders or projections, appearing sometimes ahnost starlike. M. querciana differs from other species by its characteristic perineal pattern round to oval in outline, sometimes with a low arch, and sunken vulva surrounded by a prominent obovate area devoid of striae. M. querciana shows some relationship to M. ovalis, but differs further fxom the latter by longer larvae, absence of annules on head of larvae, and rarity of males. Examination of specimens of M. camelliae n.sp. and M. querciana n.sp. with the scanning electron microscope confirmed observations made by optical microscopy and revealed diagnostic and other structures in greater detail. In greenhouse host tests, M. camelliae infected camellia heavily, showed moderate infection on oxalis, only a trace infection on tomato, and no infection on five other plants tested; and M. querciana attacked pin oak, red oak, and American chestnut heavily, but did not infect nine other test plants. In another test, pin oak seedlings did not become infected when heavily inoculated with and grown in the presence of two populations of M. incognita incognita and one of M. incognita acrita. The common names "camellia root-knot nematode" and "oak root-knot nematode" are respectively proposed for M. camelliae and M. querciana. PMID:19305554

  3. Evaluation of 15 Trifolium spp. and of Medicago sativa as Hosts of Four Meloidogyne spp. Found in New Zealand

    Mercer, C. F.; Miller, K. J.

    1997-01-01

    The predominant root-knot nematode in New Zealand pastures is Meloidogyne trifoliophila, identified until recently as M. hapla. Clarification was needed on the host range of these two species on legumes found in New Zealand pastures and on clover species closely related to Trifolium repens. In a greenhouse test, 15 Trifolium spp. and Medicago sativa were inoculated with eggs of M. trifoliophila, M. hapla, M. incognita, or M. javanica. All legumes tested were hosts to some degree to each of th...

  4. Pathogenic Variability Among Isolates of Meloidogyne javanica on Capsicum annum

    B. KHAN; A. A. Khan; Khan, M.R.

    2003-01-01

    Meloidogyne javanica isolates were collected from nine districts of Uttar Pradesh. These isolates showed pathogenic variability when inoculated on the pepper cultivars California Wonder and Suryamukhi Green. Meloidogyne javanica that infected Suryamukhi Green but not California Wonder were designated as pepper race 1 and the populations that infected both the cultivars were designated pepper race 2. Race 1 was more frequent than race 2 in Almora, Pauri Garhwal, Basti, Gorakhpur, and Deoria, w...

  5. Effect of winter cover crops on nematode population levels in north Florida.

    Wang, K-H; McSorley, R; Gallaher, R N

    2004-12-01

    Two experiments were conducted in north-central Florida to examine the effects of various winter cover crops on plant-parasitic nematode populations through time. In the first experiment, six winter cover crops were rotated with summer corn (Zea mays), arranged in a randomized complete block design. The cover crops evaluated were wheat (Triticum aestivum), rye (Secale cereale), oat (Avena sativa), lupine (Lupinus angustifolius), hairy vetch (Vicia villosa), and crimson clover (Trifolium incarnatum). At the end of the corn crop in year 1, population densities of Meloidogyne incognita were lowest on corn following rye or oat (P sunn hemp (Crotalaria juncea), and corn. Population densities of M. incognita and Helicotylenchus dihystera were affected by previous tropical cover crops (P sunn hemp in the fall maintained the lowest M. incognita and H. dihystera numbers. Results suggest that winter cover crops tested did not suppress plant-parasitic nematodes effectively. Planting tropical cover crops such as sunn hemp after corn in a triple-cropping system with winter cover crops may provide more versatile nematode management strategies in northern Florida. PMID:19262833

  6. Enhanced Synthesis of Antioxidant Enzymes, Defense Proteins and Leghemoglobin in Rhizobium-Free Cowpea Roots after Challenging with Meloydogine incognita

    Jose T. A. Oliveira

    2014-11-01

    Full Text Available The root knot nematodes (RKN, Meloydogine spp., particularly Meloidogyne incognita and Meloidogyne javanica species, parasitize several plant species and are responsible for large annual yield losses all over the world. Only a few available chemical nematicides are still authorized for RKN control owing to environmental and health reasons. Thus, plant resistance is currently considered the method of choice for controlling RKN, and research performed on the molecular interactions between plants and nematodes to identify genes of interest is of paramount importance. The present work aimed to identify the differential accumulation of root proteins of a resistant cowpea genotype (CE-31 inoculated with M. incognita (Race 3 in comparison with mock-inoculated control, using 2D electrophoresis assay, mass spectrometry identification and gene expression analyses by RT-PCR. The results showed that at least 22 proteins were differentially represented in response to RKN challenge of cowpea roots mainly within 4–6 days after inoculation. Amongst the up-represented proteins were SOD, APX, PR-1, β-1,3-glucanase, chitinases, cysteine protease, secondary metabolism enzymes, key enzymes involved in ethylene biosynthesis, proteins involved in MAPK pathway signaling and, surprisingly, leghemoglobin in non-rhizobium-bacterized cowpea. These findings show that an important rearrangement in the resistant cowpea root proteome occurred following challenge with M. incognita.

  7. Reproduction of Meloidogyne chitwoodi on Popcorn Cultivars

    Cardwell, D. M.; Ingham, R. E.

    1997-01-01

    Popcorn cultivars were evaluated in field and greenhouse tests for resistance to the Columbia root-knot nematode, Meloidogyne chitwoodi, as potential resistant crops in potato rotations. A nematode reproductive factor (Rf) was calculated for each cultivar. Reproductive factor values also were compared on a relative basis as percentages of the Rf on a susceptible field corn standard, Pioneer 3578. Popcorn cultivars W206 and Robust 33-77 consistently supported low population densities of M. chi...

  8. Response of Meloidogyne spp., Heterodera glycines, and Radopholus similis to Tannic Acid

    Hewlett, T. E.; Hewlett, E. M.; Dickson, D. W.

    1997-01-01

    Tannins, which are water-soluble polyphenols, are toxic to numerous fungi, bacteria, and yeasts. Our objectives were to study the efficacy of tannic acid in control of Meloidogyne arenaria on tomato and its effects on the behavior of M. arenaria, M. incognita, Heterodera glycines, and Radopholus similis. Three concentrations of tannic acid, 0.1, 1.0, and 10 g/500 cm³ of soil, were applied preplant (powder) and at-plant (powder and drench) into soil infested with M. arenaria. Tannic acid at th...

  9. Molecular Characterisation and Diagnosis of Root-Knot Nematodes (Meloidogyne spp.) from Turfgrasses in North Carolina, USA

    Ye, Weimin; Zeng, Yongsan; Kerns, James

    2015-01-01

    Root-knot nematodes (Meloidogyne spp.) are the most common and destructive plant-parasitic nematode group worldwide and adversely influence both crop quality and yield. In this study, a total of 51 root-knot nematode populations from turfgrasses were tested, of which 44 were from North Carolina, 6 from South Carolina and 1 from Virginia. Molecular characterisation was performed on these samples by DNA sequencing on the ribosomal DNA 18S, ITS and 28S D2/D3. Species-specific primers were developed to identify turfgrass root-knot nematode through simplex or duplex PCR. Four species were identified, including M. marylandi Jepson & Golden in Jepson, 1987, M. graminis (Sledge & Golden, 1964) Whitehead, 1968, M. incognita (Kofoid & White, 1919) Chitwood, 1949 and M. naasi Franklin, 1965 through a combined analysis of DNA sequencing and PCR by species-specific primers. M. marylandi has been reported from North Carolina and South Carolina for the first time. Molecular diagnosis using PCR by species-specific primers provides a rapid and cheap species identification approach for turfgrass root-knot nematodes. PMID:26599462

  10. Evidence of Differences between the Communities of Arbuscular Mycorrhizal Fungi Colonizing Galls and Roots of Prunus persica Infected by the Root-Knot Nematode Meloidogyne incognita▿

    Alguacil, Maria del Mar; Torrecillas, Emma; Lozano, Zenaida; Roldán, Antonio

    2011-01-01

    Arbuscular mycorrhizal fungi (AMF) play important roles as plant protection agents, reducing or suppressing nematode colonization. However, it has never been investigated whether the galls produced in roots by nematode infection are colonized by AMF. This study tested whether galls produced by Meloidogyne incognita infection in Prunus persica roots are colonized by AMF. We also determined the changes in AMF composition and biodiversity mediated by infection with this root-knot nematode. DNA f...

  11. Host Range of Meloidogyne Arenaria (NEAL, 1889) Chitwood, 1949 (Nematoda: Meloidogynidae) in Spain

    Lpez Prez, J. A.; Escuer, M.; Dez Rojo, M. A.; Robertson, Lee; Piedra Buena, A.; Lpez Cepero, J.; Bello Prez, Antonio

    2011-01-01

    The distribution of Meloidogyne arenaria in Spain was revised and new samples collected from representative areas. Species and races of the populations were determined by morphometrics, differential host tests and SCAR-PCR. Meloidogyne arenaria was found most often in warm areas, but it can occur in Northern Spain in greenhouses. A total of 125 citations were found, corresponding to 45 different host plants, of which 41 new reports (32.8%) are from this study. The populations stud...

  12. Survey of Meloidogyne spp. in Tomato Production Fields of Baix Llobregat County, Spain

    Sorribas, F.J.; Verdejo-Lucas, S.

    1994-01-01

    A survey was conducted to determine the frequency and abundance of Meloidogyne spp. in tomato production sites located in Baix Llobregat County, Barcelona, Spain. Forty-five sites were sampled before planting and at harvest from February to October, 1991. Meloidogyne spp. occurred in 49% of the sites sampled. Preplant population densities ranged from 10 to 220 (x? = 110)juveniles/ 250 cm soil, and final population densities ranged from 20 to 1,530 (x? = 410)juveniles/250 cm soil. Final popu...

  13. Tourism Incognita: Experiencing the Liminal Edge of Destination Places

    Lew, Alan A.

    2013-01-01

    In the age of European exploration, terra incognita referred to lands that were largely unknown to Europeans.  In the world of contemporary tourism, tourism incognita refers to the lands and experiences that are largely unknown to the global mass tourism industry (tourism cognita). Tourism incognita includes specialty niche tourisms that operate on the edge and beyond of mass tourism, as well as the entire world of non-tourism places.  Examples of tourism cognita and tourism incognita that ar...

  14. Effects of management practices on nematode and fungus populations and cucumber yield.

    Johnson, A W; Sumner, D R; Jaworski, C A

    1979-01-01

    Three crops of cucumber were grown in succession in beds by use of trickle irrigation, plastic film mulch, and soil chemical treatments over a 17-month period, including a fallow winter season. Total yield for the three crops was highest (1208 quintals/ha) in film-mulched plots treated with MBR-CP, and next-highest in film-mulched plots treated with DD-MENCS (1094 quintals/ha); total yield was only 456 quintals/ha in film-mulched control (untreated) plots. Yield in untreated film-mulched plots was 256% of that in untreated unmulched plots (178 quintals/ha). Plant growth and yields were greatest when populations of nematodes and soil-borne fungi were suppressed to very low levels. The residual control by soil treatments lasted longest on Meloidogyne incognita and Fusarium solani. PMID:19305534

  15. Efeito da Incorporao de Folhas de Nim ao Solo sobre o Complexo Fusarium x Meloidogyne em Quiabeiro Effect of amendment of soil with neem leaf on Fusarium x Meloidogyne on okra

    Gilson Soares da Silva

    2008-12-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da incorporao de folhas frescas de nim (Azadirachta indica ao solo, sobre o complexo Fusarium x Meloidogyne em quiabeiro (Abelmoschus esculentum em um experimento realizado em condies de casa de vegetao. Os tratamentos constaram da adio de 25g ou 50g de folhas trituradas/kg de solo previamente autoclavado e inoculado com M. incognita, Fusarium oxysporum f. sp. vasinfectum, juntos e isoladamente, contidos em vasos com capacidade de 2 L. Solo sem folhas de nim serviu como testemunha. O experimento foi realizado seguindo um delineamento inteiramente casualizado com seis repeties, sendo cada repetio representada por um vaso com 5 plantas. As folhas foram incorporadas 30 dias antes do plantio e a avaliao deu-se 90 dias aps o plantio, adotando-se a percentagem de plantas mortas como parmetro para avaliar o efeito dos tratamentos. A incorporao de 50g de folhas frescas de nim foi eficiente para o controle de Meloidogyne e Fusarium isoladamente, bem como na interao desses patgenos. A incorporao de 25g de folhas de nim mostrou-se eficiente apenas para o controle de Meloidogyne isoladamente.The objective of this study was to investigate the effect of soil ammendment with neem (Azadirachta indica leaf on the complex Fusarium x Meloidogyne in okra (Abelmoschus esculentum in greenhouse conditions. The treatments consisted of the addition of 25g or 50g of leaves per kg of soil and infested with M. incognita and Fusarium oxysporum f. sp. vasinfectum, together and separately, contained in pots with capacity of 2 L. Soil without supplement it served as the control. The experimental design was completely randomized with six replications and five plants per pot. The leaves were incorporate 30 days before planting and the evaluation 90 days later. The percentagem of dead plants was used to evaluate the efficiency of neem. The incorporation of 50g of fresh neem leaves was efficient in the control of both Meloidogyne and Fusarium separately as well as in their interaction. The incorporation of 25g of neem leaves was shown efficient just for the control of Meloidogyne separately.

  16. Host Status of 32 Plant Species to Meloidogyne konaensis

    Zhang, Fengru; Schmitt, D.P.

    1994-01-01

    A host suitability study of 32 plant species to Meloidogyne konaensis included 54 vegetable cultivars, 12 field crop cultivars, one Gardenia sp., and two weed species. Host suitability was classified according to a M. konaensis reproductive factor: final population density (Pf) (eggs + J2) / initial population density (Pi) (eggs). The number of eggs per gram dry root, and a galling index was also included. Reproductive factor ranges and percentages of plants in the ranges were as follows: Pf/...

  17. Additive Effects of Meloidogyne arenaria and Sclerotinin rolfsii on Peanut

    Starr, J. L.; Shim, M.-Y.; Lee, T. A.; Simpson, C E

    1996-01-01

    Field observations have suggested that infection of peanut by Meloidogyne arenaria increases the incidence of southern blight caused by Sclerotium rolfsii. Three factorial experiments in microplots were conducted to determine if interactions between M. arenaria and S. rolfsii influenced final nematode population densities, incidence of southern blight, or pod yield. Treatments included four or five initial population densities of M. arenaria and three inoculum rates of S. rolfsii. Final nemat...

  18. Plant Nutrient Partitioning in Coffee Infected with Meloidogyne konaensis

    Hurchanik, Denise; Schmitt, D.P.; Hue, N. V.; Sipes, B.S.

    2004-01-01

    Two experiments were conducted to assess nutrient partitioning in coffee (Coffea arabica cv. Typica land race Guatemala) infected with Meloidogyne konaensis. Nutrient levels were quantified from soil, roots, and leaves. In the first experiment, 500-cm3 aliquants of a Kealakekua Andisol were infested with four initial population densities of M. konaensis ranging from 0 to 1,500 freshly hatched second-stage juveniles. Coffee plants (~3 months old) were transplanted into the soil and grown for 2...

  19. Effects of management practices on nematode and fungi populations and okra yield.

    Johnson, A W; Sumner, D R; Jaworski, C A; Chalfant, R B

    1977-04-01

    Okra was grown in field plots of Tifton loamy sand naturally infested with the nematodes Meloidogyne incognita and Criconemoides ornalus and the pathogenic fungi Fusarium oxysporum, F. solani, F. roseum, and Pythium spp. Plots were treated with various soil pesticides and left exposed or covered with biodegradable paper film mulch under trickle irrigation. Soil was assayed for nematodes and fungi, and plant roots were examined for root-rot and insect damage. Fewer nematodes and fungi generally were recovered from soil treated with DD-MENCS (with and without film mulch) or methyl bromide-chloropicrin (2:1) (MBC) and film mulch than from nontreated soil. Funfigation with DD-MENCS or MBC suppressed populations of M. incognita, C. ornatus, F. oxysporum, F. solani, F. roseum, and Pythium spp. Ethoprop (alone or combined with other pesticides), sodium azide, and chloroneb were less effective than DD-MENCS and MBC. Plant growth anti yield were greatest when nematodes and pathogenic fungi were controlled. Yield was increased 3-fold by DD-MENCS + film mulch or MBC + film mulch in comparison with the average yield of okra produced in Georgia. The root-knot nematode-Fusarium wilt complex was most severe in nonfuntigated soil. PMID:19305580

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

    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 (P4+ -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 NH4+ -N ha-1) in 2007 and 2008 and multiple applications (25, 50, 25 kg NH4+-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.

  1. Mustard seed meal mixtures: management of Meloidogyne incognita on pepper and potential phytotoxicity

    Meals produced when oil is extracted from brassicaceous seeds have been shown to suppress weeds and soilborne pathogens. These seed meals are commonly used individually as soil amendments; the goal of this research was to evaluate seed meal mixes of Brassica juncea Bj and Sinapis alba (Sa) against ...

  2. Effects of metabolites of Gliocladium Roseum on egg hatch and juvenile mortality of Meloidogyne incognita

    Root-knot disease caused by root-knot nematode is a serious yield limiting factor for several economically important crops including soybean, vegetables, fruit trees, tea, tobacco, and medicinal plants. Control of nematode is currently mostly limited to application of soil nematicides, which are cos...

  3. Utility of Grafting for Managing Southern Root-knot Nematode, Meloidogyne Incognita, in Watermelon

    Four bottlegourd (Lagenaria siceraria) cultivars, one squash (Cucurbita moschata x C. maxima) hybrid, four wild watermelon (Citrullus lanatus var. citroides) germplasm lines, and one commercial wild watermelon (C. lanatus var. citroides) cultivar were evaluated as rootstocks for cultivated watermelo...

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

    Atsushi Takada; Erika Sato; Koki Toyota; Yu Yu Min

    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 ( < . 0 5 ) lower and the growth better in pots applied with ADS (100 and 200 mg N H + 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 N H + 4 -N ha...

  5. Greenhouse evaluation of capsicum rootstocks for management of meloidogyne incognita on grafted bell pepper

    The growth, development, and nematode susceptibility of various rootstock genotypes grafted to a commercial bell pepper variety scion were evaluated in a series of greenhouse experiments. Nine rootstocks including Caribbean Red Habanero, PA-136 , Keystone Resistant Giant, Yolo Wonder, Car...

  6. Comparison of two sympatric Pasteuria populations isolated from a tropical vertisol soil.

    Sharma, S B; Davies, K G

    1996-07-01

    An isolate of Pasteuria (designated PPMJ) recovered from the root-knot nematode Meloidogyne javanica, was characterized using host preference, spore morphometrics, and serology, and compared with another sympatric Pasteuria isolate (designated PPHC) collected from the cyst nematode, Heterodera cajani. PPMJ spores were larger (x 1.5) than the PPHC spores and had a mean diameter of 3.4 μm after fixation for electron microscopy. The central body of PPMJ spores was about twice as big as the central body of PPHC spores. The host preference tests, based on spore attachment to the nematode cuticle, revealed that Meloidogyne incognita, M. javanica, M. hapla, Pratylenchus coffeae, and Pratylenchus sp. were hosts of PPMJ but not of PPHC. It was found that males of Radopholus similis were hosts of PPHC. Western blot analysis of spore extracts probed with a polyclonal antiserum raised against PPHC spores showed an antigenic ladder which had similarities to lipopolysaccharide; another antiserum revealed differences in the molecular weight of antigens of the different spore isolates. Population diversity can therefore be vastly altered by the maintenance and culture of the bacterium on a particular host. The implications of these results are discussed in relation to the use of Pasteuria as a biological control agent. PMID:24415311

  7. 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.

    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 level of resistance of each cultivar. The results showed that cultivar Okinawa did not present any root galls and also had a superior growth than the other cultivars. The cultivars R-15-2 and Aldrighi presented small numbers of galls in the roots, they were considered resistant to nematodes. On the other hand, the cultivar GF677 presented the largest number of galls in the roots, achieving 126 galls/g of root.

  8. Management of Root-Nematode (Meloidogyne SPP)

    Greenhouse and field experiments were undertaken to determine the possibility of using soil amendments with different C:N levels or applied at different rates and times in the control of root-knot nematodes (Meloidogyne spp.)in tomato c.v Cal J.A naturally infested field was used while artificial inoculation was done in the greenhouse. Root galling was rated on a scale of 0-10, nematode population was estimated by counting second stage juveniles extracted from 200 cm3 soil and fruit yields were recorded at the end of the season. Nematode population densities and galling indices were significantly (P< or=0.05) lower in amended soils compared to the control. Application of the amendments also resulted in significant (P< or=0.05) increase in yields. Chicken manure, compost manure, neem products and pig manure were were the most effective amendments. Fresh chicken manure had a more suppressive effect on nematode than when the manure was decomposed within or outside a nematode infested field. A general decrease in juvenile populations and galling was observed with increase of organic amendments applied

  9. Genetic variation among parthenogenetic Meloidogyne species revealed by AFLPs and 2D-protein electrophoresis contrasted to morphology

    Van der Beek, J. G.; Folkertsma, R.; Zijlstra, C.; Koert, P.H.G., van; Poleij, L.M.; Bakker, J.

    1998-01-01

    Des isolats appartenant aux espèces parthénogénétiques améiotiques #Meloidogyne arenaria$, #M. hapla$ race B, #M. incognita$, #M. javanica$ et parthénogénéiques méiotiques #M. chitwoodi$, #M. fallax$, #M. hapla$ race A, #M. naasi$ ont été comparés quant à leurs protéines totales solubles - par électrophorèse sur gel en deux dimensions (2-DGE) -, leur ADN génomique total - par AFLP - et leurs caractères morphologiques - par mensurations directes et données provenant de la littérature. Ces donn...

  10. Identificación de genes candidatos de patogenicidad en la interacción de la cepa cenicafe 9501 con el nemátodo del nudo radical meloidogyne spp.

    Cardona Bustos, Nadya Lorena; Betancur Pérez, Jhon Fredy; Rivera Serna, Luis Fernando; Gaitán Bustamante, Alvaro

    2012-01-01

    Resumen. 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 ide...

  11. 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

    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 groups was less than those in the control group with statistical significant difference (p 0.05. It is concluded that the foliage of T. minutaadded as organic amendment at 20, 35 and 50% to the culture soil for C. annuumplants limits the M. incognitaroot galling. That suggests its potential use in the control of this nematode.

  12. Response of Meloidogyne spp., Heterodera glycines, and Radopholus similis to Tannic Acid.

    Hewlett, T E; Hewlett, E M; Dickson, D W

    1997-12-01

    Tannins, which are water-soluble polyphenols, are toxic to numerous fungi, bacteria, and yeasts. Our objectives were to study the efficacy of tannic acid in control of Meloidogyne arenaria on tomato and its effects on the behavior of M. arenaria, M. incognita, Heterodera glycines, and Radopholus similis. Three concentrations of tannic acid, 0.1, 1.0, and 10 g/500 cm(3) of soil, were applied preplant (powder) and at-plant (powder and drench) into soil infested with M. arenaria. Tannic acid at the 1.0-g rate reduced galling compared with the untreated control, regardless of methods of application. The 0.1-g rate resulted in no reduction in galling when applied preplant but reduced galling when applied as a drench and in one of two experiments when applied at-plant. The 10-g rate was phytotoxic to tomato seedlings except when applied 7 days preplant. In the latter case, root galling was suppressed to very low numbers. In behavior studies on water agar, Meloidogyne second-stage juveniles were attracted to areas with an increasing tannic acid gradient. Radopholus similis was repelled from the tannic acid gradient in one of two experiments. There was no effect on H. glycines. The response of M. arenaria second-stage juveniles to different concentrations of tannic acid dissolved in alginate was tested. Movement behavior of the second-stage juveniles were observed at 1,000 and 10,000 mug/ml of tannic acid, but not at 10 and 100 mug/ml. PMID:19274278

  13. Resistance and Host-response of Selected Plants to Meloidogyne megadora

    de Almeida, A. M. S. F.; de A. Santos, M. S. N.

    2002-01-01

    Fourteen plant species, including 30 genotypes, were assessed for host suitability to Meloidogyne megadora in a growth room at 20 to 28°C. Host suitability was based on the gall index (GI) and the reproduction factor (Rf):final population density (Pf)/initial population density (Pi). The presence of distinct galling was observed on roots of six plant species, and reproduction occurred on five of the 14 species tested. Three cultivars of cantaloupe (cvs. Branco do Ribatejo, Concerto, and Galia...

  14. Effets de l'iboga (Tabernanthe iboga Baillon sur les nmatodes galles (Meloidogyne sp. parasites de tomate

    Bayonne, L.

    2005-01-01

    Full Text Available Effects of Iboga (Tabernanthe iboga Baillon on the Root-Knot Nematodes (Meloidogyne sp. in Tomato. The tomato crop in tropical areas arises phytosanitary problems because of many disastrous parasites among which the Meloidogyne genus are in the origin of important damages and the origin of the tomato production decrease in Gabon. How can people manage to control these parasites by using local plants? Out of the chemical control, the works we have done, focused on the usage of Tabernanthe iboga as a biological control agent of crop protection. The results of these experiences show that the iboga decoction seems to be able to reduce considerably the Meloidogyne population, and to protect the crop.

  15. Meloidogyne partityla on Pecan Isozyme Phenotypes and Other Host

    Starr, J. L.; Tomaszewski, E. K.; Mundo-Ocampo, M.; Baldwin, J.G.

    1996-01-01

    Meloidogyne sp. from five pecan (Carya illinoensis) orchards in Texas were distinctive in host range and iszoyme profiles from common species of Meloidogyne but were morphologically congruent with Meloidogyne partityla Kleynhans, a species previously known only in South Africa. In addition to pecan, species of walnut (Juglans hindsii and J. regia) and hickory (C. ovata) also were hosts. No reproduction was observed on 15 other plant species from nine families, including several common hosts o...

  16. Interaction between Meloidogyne enterolobii and Helicotylenchus dihysteroides in guava seedlings

    Vicente Martins Gomes

    2014-07-01

    Full Text Available In order to evaluate the effect of joint infection by Meloidogyne enterolobii and Helicotylenchus dihysteroides on vegetative growth of guava seedlings (Psidium guajava L., as well as to observe symptoms caused by pathogens in host plants, an experiment was conducted in microplots. In these experimental units, suspensions were used containing H. dihysteroides and M. enterolobii. The plants were separately inoculated with H. dihysteroides and jointly inoculated with H. dihysteroides and M. enterolobii, and the blank controls were represented by noninoculated plants. No significant differences were observed between treatments related to morpho-physiological variables of guava seedlings, but joint inoculation resulted in a reduced final population of H. dihysteroides. It was also concluded that neither infection by H. dihysteroides alone nor a joint infection by the two pathogens caused any damage to guava seedlings.

  17. Reaction of vegetables and aromatic plants to Meloidogyne javanica and M. incognita Reação de hortaliças e plantas aromáticas aos nematoides Meloidogyne javanica e M. incognita

    Cláudia Regina Dias-Arieira; Tatiana PL da Cunha; Fernando Marcelo Chiamolera; Heriksen H Puerari; Fabio Biela; Simone de M Santana

    2012-01-01

    For this research we used 15 day-old seedlings which were transplanted to 2 L pots and inoculated with 4,000 nematode eggs plus juveniles (J2). After 60 days, the root systems were removed and the number of galls and eggs evaluated and used to calculate the nematode reproduction factor (RF). The tomato cv. Santa Cruz was used as a susceptible control. The experimental design was completely randomized, with six replications. Averages were compared using the Tukey or Scott-Knott test at 5%. For...

  18. Evaluation of the effect powder and aqueous extracts of some plant species on tomato yield and reproduction of Meloidogyne incognita

    Hoseinpoor et al.

    2012-01-01

    In a pot experiment, shoot extracts from dried powder mixtures combining four extracts from the following five plant species (Euphorbia helioscopia[F], Descurainia Sophia [K], Gypsophila pilosa[G], Eruca sativa [M] and P. lanceolata [B]) were mixed with soil. Effects of powdered and aqueous extracts of different combinations of plant species were tested on the activity of root-knot nematode and vegetative growth indices of the host plant. Results showed that root galling was significantly sup...

  19. Transgenic tobacco plants constitutively expressing Arabidopsis NPR1 show enhanced resistance to root-knot nematode, Meloidogyne incognita

    Prasad JS; Somasekhar N; Priya D Bhanu; Kirti PB

    2011-01-01

    Abstract In Arabidopsis, non-expressor of pathogenesis related genes-1, NPR1 has been shown to be a positive regulator of the salicylic acid controlled systemic acquired resistance pathway and modulates the cross talk between SA and JA signaling. Transgenic plants expressing AtNPR1 constitutively exhibited resistance against pathogens as well as herbivory. In the present study, tobacco transgenic plants expressing AtNPR1 were studied further for their response to infection by the sedentary en...

  20. Relationship Between Heterodera schachtii, Meloidogyne hapla, and Nacobbus aberrans on Sugarbeet

    Inserra, R. N.; Griffin, G D; Vovlas, N.; J.L. Anderson; Kerr, E D

    1984-01-01

    Heterodera schachtii, Meloidogyne hapla, and Nacobbus aberrans either alone, or in various combinations with each other, can, when inoculated at a concentration of 12 second-stage juveniles/ cm³ of soil, cause a significant (P = 0.01) suppression of growth of sugarbeet (cv. Tasco AH14) seedlings. M. hapla and H. schachtii decreased growth of sugarbeet more than N. aberrans over a 60-day period. The adverse effect of N. aberrans on the final population/initial population (Pf/Pi) ratio for eith...

  1. Host Status of Crotalaria juncea, Sesamum indicum, Dolichos lablab, and Elymus glaucus to Meloidogyne javanica

    Araya, M.; Caswell-Chen, E.P.

    1994-01-01

    Reproduction of Meloidogyne javanica on Crotalaria juncea PI 207657 and cv. Tropic Sun, Sesamum indicum, Dolichos lablab, and Elymus glaucus was assessed using a root-gall index, a reproductive index obtained by dividing the final population of juveniles (J2) in soil by the initial J2 population (Pf/Pi), and the number of J2 per gram of root recovered from roots by mist chamber extraction. Lycopersicon esculentum (cv. UC 204 C) was included as a susceptible host. The root-gall index and soil ...

  2. Meloidogyne paranaensis n. sp. (Nemata: Meloidogynidae), a Root-Knot Nematode Parasitizing Coffee in Brazil.

    Carneiro, R M; Carneiro, R G; Abrantes, I M; Santos, M S; Almeida, M R

    1996-06-01

    A root-knot nematode parasitizing coffee in Paran State, Brazil, is described as Meloidogyne paranaensis n. sp. The suggested common name is Paran coffee root-knot nematode. The perineal pattern is similar to that of M. incognita; the labial disc and medial lips of the female are fused and asymmetric and rectangular; the lateral lips are small, triangular, and fused laterally with the head region. The female stylet is 15.0-17.5 mum long, with broad, distinctly set-off knobs; the distance from the dorsal esophageal gland orifice (DGO) to the stylet base is 4.2-5.5 mum. Males have a high, round head cap continuous with the body contour. The labial disc is fused with the medial lips to form an elongate lip structure. The head region is frequently marked by an incomplete annulation. The stylet is robust, 20-27 mum long, usually with round to transversely elongate knobs, sometimes with one or two projections protruding from the shaft. The stylet length of second-stage juveniles is 13-14 mum, the distance of the DGO to the stylet base is 4.0-4.5 mum, and the tail length is 48-51 mum. Biochemically, the esterase (F) and malate dehydrogenase (N) phenotypes are the most useful characters to differentiate M. paranaensis from other species. However, the esterase phenotype appears similar to that of M. konaensis. Reproduction is by mitotic parthenogenesis, 3n = 50-52. In differential host tests, tobacco, watermelon, and tomato were good hosts, whereas cotton, pepper, and peanut were nonhosts. PMID:19277133

  3. Effect of Aldicarb, Ethoprop, and Carbofuran on Control of Coffee Root-knot Nematode, Meloidogyne exigua.

    Huang, S P; Resende, I C; de Souza, D E; Campos, V P

    1983-10-01

    Egg hatch of Meloidogyne exigua was significantly inhibited in 14 days pretreatment with aldicarb, ethoprop, or carbofnran at concentrations higher than 0.1 mug/ml; these eggs were found to delay hatch in 19 days posttreatment in ethoprop. Aldicarb and carbofuran solutions at concentrations greater than 0.1 mug/ml significantly decreased the motility and the life span of the second-stage juveniles; aldicarb was more toxic than carbofuran to the nematode. In a field test, aldicarb (Temik 10G), ethoprop (Mocap 10G), and carbofuran (Furadan 5G and Furadan Liquid 350F) significantly decreased M. exigua populations. PMID:19295839

  4. 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.

    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 genera, this isolate has been labeled in the mean time as CENICAFE 9501. Given its potential as biological control agent, the identification of canditate genes involved in pathogenicity processes on Meloidogyne eggs was proposed. With this purpose, differential libraries were constructed using the subtractive hybridization method. Sequencing of 188 clones allowed the identification of 80 unigenes, with the highest percentage corresponding to sequences without homology (32%, followed by candidate genes for pathogenesis (22%, cellular transport (17%, protein synthesis (11% and in lesser degree those involved with transcription and primary metabolism (18%. Among those genes with reading frames showing homology to proteins involved in pathogenicity can be found a peptidase, a ubiquitination receptor, a deubiquitinase, a ubiquinone oxydoreductase, a protein related to the degradation of the cell wall, a glycosyl hydrolase and fatty acid hydrolase, as well as a serine protease. A validation of the putative function of these genes is neccesary in order to increase the basic knowledge of the physiology of this fungus with bioregulation potential.

  5. REDUO DA TAXA DE EXPANSO FOLIAR DE TOMATEIROS PARASITADOS POR Meloidogyne javanica

    BELAN, Lenidas Leoni

    2011-11-01

    Full Text Available Among the problems affecting tomato production phytopatogens are the most important.Among these, nematodes of the genus Meloidogyne cause large annual economic yield losses in tomatocultivation around the world. The knowledge of the physiological indices of growth is extremely important in theinterpretation of pathogen-host-environment relationships. This way, the effect of growing populations of M.javanica (Treub on the leaf area expansion rate (LAX during the early development of cherry tomato accesswas evaluated. The negative effects of nematodes were expressed in early development of tomato plants. Therewas linear increase in population (FP of M. javanica in all cherry tomato access as it was increased the initiallevel of nematode, resulting in reduction of linear TEAF. Thus any management practice that reduces thenematode population of soil during the growing season of tomatoes, will may favor the growth and developmentof plants and subsequently the production.Entre os problemas que mais afetam a produo do tomateiro esto os fitopatgenos. Dentreesses, os nematoides do gnero Meloidogyne causam considerveis perdas econmicas anuais no cultivo detomate em todo o mundo. O conhecimento dos ndices fisiolgicos de crescimento extremamente importantena interpretao das relaes patgeno-hospedeiro-ambiente. Neste contexto, quantificou-se a influncia doparasitismo de populaes crescentes de M. javanica (Treub sobre a taxa expanso da rea foliar (TEAF nafase de desenvolvimento inicial de acessos de tomateiro tipo cereja. Os efeitos negativos do parasitismo dosnematoides se manifestaram na fase inicial de desenvolvimento das plantas. Verificou-se crescimento linear dapopulao final (PF de M. javanica em todos os acessos de tomateiro cereja avaliados medida que seaumentou o nvel do inculo inicial do nematoide, ocasionando reduo linear da TEAF. Dessa forma, prticasde manejo que reduzam a populao de nematoides do solo durante a fase vegetativa dos tomateiros, poderofavorecer o crescimento e desenvolvimento das plantas e a consequente produo de frutos.

  6. Molecular Characterisation and Diagnosis of Root-Knot Nematodes (Meloidogyne spp.) from Turfgrasses in North Carolina, USA

    Ye, Weimin; Zeng, Yongsan; Kerns, James

    2015-01-01

    Root-knot nematodes (Meloidogyne spp.) are the most common and destructive plant-parasitic nematode group worldwide and adversely influence both crop quality and yield. In this study, a total of 51 root-knot nematode populations from turfgrasses were tested, of which 44 were from North Carolina, 6 from South Carolina and 1 from Virginia. Molecular characterisation was performed on these samples by DNA sequencing on the ribosomal DNA 18S, ITS and 28S D2/D3. Species-specific primers were develo...

  7. The Convective Boundary Layer and the Terra Incognita

    Zhou, B.; Simon, J. S.; Chow, F. K.

    2013-12-01

    Numerical simulations of the convective boundary layer (CBL) are performed to investigate model behavior in the gray zone, also known as the 'terra incognita' (Wyngaard 2004). The gray zone of the CBL refers to a range of model grid spacing that is comparable to the size of the most energetic convective eddies, which are on the order of the boundary layer depth. Using Rayleigh-Benard thermal instability theory as a reference, it is shown that the gray zone modeling is not just a numerical challenge, but also poses dynamical difficulties. When the grid spacing falls within the CBL gray zone, grid dependent convection can occur. The size of the initial instability structures is set by the grid spacing rather than the natural state of the flow. The resulting artificial convective structures change the higher order flow statistics and pose fundamental difficulties for gray zone modeling applications. If convection in the gray zone is different from its natural state, we are then faced with the question: should we, or should we not allow convection to happen in the gray zone? This work attempts to shed some light on this issue.

  8. Interaction between Meloidogyne enterolobii and Helicotylenchus dihysteroides in guava seedlings

    Vicente Martins Gomes; Ricardo Moreira de Souza; Thiago de Freitas Ferreira; Guilherme B. Miranda; Alexandre Macedo Almeida; Renata Rodrigues Robaina

    2014-01-01

    In order to evaluate the effect of joint infection by Meloidogyne enterolobii and Helicotylenchus dihysteroides on vegetative growth of guava seedlings (Psidium guajava L.), as well as to observe symptoms caused by pathogens in host plants, an experiment was conducted in microplots. In these experimental units, suspensions were used containing H. dihysteroides and M. enterolobii. The plants were separately inoculated with H. dihysteroides and jointly inoculated with H. dihysteroid...

  9. Grafting guava on cattley guava resistant to Meloidogyne enterolobii

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

    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...

  10. Ethylene Production by Meloidogyne spp.-Infected Plants

    Glazer, I.; Orion, D; Apelbaum, A.

    1985-01-01

    Gall size and rates of ethylene production by various hosts infected with Meloidogyne javanica and by excised tomato root cultures infected with M. javanica or M. hapla were measured. Infection with M. javanica increased the rate of ethylene production in dicotyledonous plants (cabbage, pea, carrot, cucumber, carnation, and tomato), but not in infected monocotyledonous plants (corn, wheat, and onion). Nematode infection induced large galls on roots of dicotyledonous, but not monocotyledonous,...

  11. Dicty_cDB: SSB550 [Dicty_cDB

    Full Text Available SS (Link to library) SSB550 (Link to dictyBase) - - - Contig-U02317-1 SSB550Z (Link to Original ... 74742.1 ra97b02.y1 Meloidogyne incognita egg pAMP1 Bird ... Meloidogyne incognita cDNA 5', mRNA sequence. 44 1 ... .4 1 AW571255 |AW571255.1 ra16b04.y2 Bird -Rao Meloidogyne incognita J2 Meloidogyne incognita ...

  12. Dicty_cDB: VSC358 [Dicty_cDB

    Full Text Available VS (Link to library) VSC358 (Link to dictyBase) - - - Contig-U06283-1 VSC358Z (Link to Original ... quence. 44 0.075 6 AW828708 |AW828708.1 ra73a06.y1 Bird -Rao Meloidogyne incognita J2 Meloidogyne incognita ... equence. 46 0.43 1 AW571037 |AW571037.1 ra15d12.y1 Bird -Rao Meloidogyne incognita J2 Meloidogyne incognita ...

  13. Dicty_cDB: SSM635 [Dicty_cDB

    Full Text Available SS (Link to library) SSM635 (Link to dictyBase) - - - Contig-U02317-1 SSM635Z (Link to Original ... some 11. 46 0.45 1 AW570934 |AW570934.1 ra13a02.y1 Bird -Rao Meloidogyne incognita J2 Meloidogyne incognita ... d pieces. 44 1.8 1 AW571311 |AW571311.1 ra16g10.y2 Bird -Rao Meloidogyne incognita J2 Meloidogyne incognita ...

  14. Control of the Root-Knot Nematode (Meloidogyne spp. on Cucumber by a Liquid Bio-Formulation Containing Chitinolytic Bacteria, Chitin and Their Products

    Woo Jong Ha

    2014-06-01

    Full Text Available A liquid bio-formulation containing chitinolytic bacteria, chitin and their products was assessed for its potential biological control against root-knot nematodes on cucumber. The bio-formulation was prepared by cultures of three chitinolytic bacteria, Chromobacterium sp. strain C-61, Lysobacter engymogenes and Serratia plymuthica in minimal medium supplemented with chitin. Under pot conditions, the bio-formulation showed better growth of cucumber plants, and less root galls and population density of Meloidogyne spp. than control media without the bio-formulation. In a greenhouse, 75-fold diluted bio-formulations were treated instead of water around cucumber plants through hoses for drip irrigation six times at 5-day intervals from the transplanting date. After 30 and 60 days, the treatment provided about 7% and 10% enhancement in the plant height and about 78% and 69% reduction in population density of Meloidogyne spp. in the rhizosphere, respectively. In addition, the experiments showed that the control effects occurred only in the soils contacted with the bio-formulation. Undiluted bio-formulations were drenched three times at 10-day intervals around cucumber plants severely infested with Meloidogyne spp. The treatment showed about 37% plant enhancement without dead plants compared with 37% death in the untreated control, and about 82% nematode reduction. These results suggest that the bio-formulation can be practically used to control the root-knot nematode on cucumber.

  15. Variation in Virulence Within Meloidogyne chitwoodi, M. fallax, and M. hapla on Solanum spp.

    van der Beek, J G; Poleij, L M; Zijlstra, C; Janssen, R; Janssen, G J

    1998-07-01

    ABSTRACT The virulence of Meloidogyne hapla, M. chitwoodi, and M. fallax was studied on genotypes of Solanum spp. in a greenhouse. Juveniles of 11 M. hapla race A isolates, 3 M. hapla race B isolates, and 5 mono-female lines of a M. hapla race A isolate were inoculated on S. chacoense, S. hougasii, and S. sparsipilum. Juveniles of eight M. chitwoodi isolates, five M. fallax isolates, and six mono-female lines of a M. chitwoodi isolate were inoculated on S. bulbocastanum, S. chacoense, S. hougasii, S. stoloniferum, and S. tuberosum. Virulence was expressed as nematode reproduction 8 weeks after inoculation. Nematode reproduction was estimated by the number of egg masses and, in one experiment, by the number of hatched second-stage juveniles per inoculated juvenile. Considerable variation in virulence and resistance was observed among M. hapla isolates and plant genotypes, respectively. The M. hapla isolate-plant species interaction was highly significant. The response to M. chitwoodi ranged from susceptible (S. tuberosum and S. chacoense) to highly resistant (S. bulbocastanum and S. hougasii). S. tuberosum was susceptible to M. fallax, whereas all four wild species were resistant. In contrast to M. hapla, no significant isolate-plant genotype interaction was obtained for M. chitwoodi or M. fallax, indicating no or little intraspecific variation in virulence. M. chitwoodi juveniles in species mixtures with M. fallax isolates appeared to be able to break the resistance of S. bulbocastanum and S. hougasii. Significant differences among mono-female lines of M. hapla and M. chitwoodi were observed, indicating heterogeneity of pathogenicity within meiotic parthenogenic Meloidogyne populations. PMID:18944937

  16. Heterodera glycines cysts contain an extensive array of endoproteases as well as inhibitors of proteases in H. glycines and Meloidogyne incognita infective juvenile stages

    Heterodera glycines cysts contain proteases, and inhibitors of protease activities in various nematode species. In this investigation, proteases in H. glycines cysts were identified using a commercially available FRET-peptide library comprising 512 peptide pools qualified to detect up to 4 endoprot...

  17. Efecto de enmiendas orgánicas y Trichoderma spp. en El manejo de Meloidogyne spp.

    Baños, Yoerlandy Santana; Concepción, Armando del Busto; Lazo, Ricardo Cruz; González, Irisley Aguiar; Morejón, Liudmila Palomino

    2010-01-01

    Los nematodos formadores de agallas (Meloidogyne spp.) constituyen una de las plagas más importantes que afectan el cultivo de hortalizas debido a las pérdidas que provocan anualmente. Con El objetivo de reducir los niveles de infestación de Meloidogyne spp. en el cultivo de tomate, se evaluó El efecto de gallinaza (2,4 kg/ha), melaza (10 l/ha) y Trichoderma spp. (9 kg/ha), comparado con un testigo sin tratar. Como resultados, se redujo significativamente el grado de infestación de Meloidogyn...

  18. Effects of some rhizosphere bacteria for the biocontrol of nematodes of the genus Meloidogyne with Arthrobotrys oligospora

    Duponnois, Robin; Ba, A.M.; Mateille, Thierry

    1998-01-01

    A été étudiée l'action d'isolats bactériens au champignon nématophage #Arthrobotrys oligospora$ ORS 18692 S7 isolé au Sénégal sur le développement du champignon (croissance saprophytique et activité prédatrice), la multiplication d'une population de #Meloidogyne mayaguensis$ sur des plants de tomate, et la croissance de la plante hôte. Trois isolats bactériens ont été capables de stimuler in vitro l'activité prédatrice du champignon et de réduire le développement d'une population de #M. mayag...

  19. Efeito do Meloidogyne javanica no crescimento da ervilha

    Sharma Ravi Datt

    2000-01-01

    Full Text Available O nematóide-das-galhas radiculares, Meloidogyne javanica, comumente causa redução em produtividade de ervilha, Pisum sativum L., no Distrito Federal. O efeito de Meloidogyne javanica no crescimento da ervilha cv. Triofin foi avaliado em cinco níveis de inóculos: 0, 10, 100, 1.000 e 10.000 ovos/kg de solo, em casa de vegetação. Houve redução progressiva no crescimento da planta com o aumento do inóculos. O fator de multiplicação foi negativamente proporcional ao inóculo inicial. A nodulação bacteriana também foi seriamente afetada em todos os níveis de inóculo, exceto no de 10 ovos/kg do solo, que apresentou 61,63% de aumento no de número de nódulos/planta.

  20. Relationship Between Heterodera schachtii, Meloidogyne hapla, and Nacobbus aberrans on Sugarbeet.

    Inserra, R N; Griffin, G D; Vovlas, N; Anderson, J L; Kerr, E D

    1984-04-01

    Heterodera schachtii, Meloidogyne hapla, and Nacobbus aberrans either alone, or in various combinations with each other, can, when inoculated at a concentration of 12 second-stage juveniles/ cm(3) of soil, cause a significant (P = 0.01) suppression of growth of sugarbeet (cv. Tasco AH14) seedlings. M. hapla and H. schachtii decreased growth of sugarbeet more than N. aberrans over a 60-day period. The adverse effect of N. aberrans on the final population/initial population (Pf/Pi) ratio for either M. hapla or H. schachtii was dependent on time, and was more accentuated on that of M. hapla than on that of H. schachtii. Neither M. hapla nor H. schachtii had an adverse effect on the Pf/ Pi ratio of N. aberrans. N. aberrans is considered to be less aggressive on sugarbeet than either H. schachtii or M. hapla. Sections of sugarbeet roots infected simultaneously with H. schachtii and N. aberrans showed scattered vascular elements between the N. aberrans syncytium located in the central part of the root and that of H. schachtii in the peripheral position. PMID:19295890

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

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

    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.

  3. INFLUENCE OF COVER CROPS IN ROTATION ON IMPROVING OKRA (ABELMOSCHUS ESCULENTUS L.) YIELD AND SUPPRESSING PARASITIC NEMATODES

    The influence of growing and incorporating summer cover crops on subsequent vegetable crop production and on population densities of the root-knot nematode (Meloidogyne incognita) was investigated in field and pot experiments at Homestead, Florida. The cover crops utilized in the field and pot exper...

  4. Mustard seed meal for management of root-knot nematode and weeds in tomato production

    Mustard seed meals of indian mustard [InM (Brassica juncea)] and yellow mustard [YeM (Sinapis alba)], alone and combined, were tested for effects on tomato (Solanum lycopersicum) plants and for suppression of southern root-knot nematode [RKN (Meloidogyne incognita)] and weed populations. In the gree...

  5. Development and Validation of LNA-Based Quantitative Real-Time PCR Assays for Detection and Identification of the Root-Knot Nematode Meloidogyne enterolobii in Complex DNA Backgrounds.

    Kiewnick, Sebastian; Frey, Jürg E; Braun-Kiewnick, Andrea

    2015-09-01

    Meloidogyne enterolobii is a quarantine root-knot nematode posing a major threat to agricultural production systems worldwide. It attacks many host plants, including important agricultural crops, ornamentals, and trees. M. enterolobii is a highly virulent and pathogenic root-knot nematode species, able to reproduce on plants resistant to other Meloidogyne spp. Significant crop damage has been reported in Asia, South America, Africa, the United States, France, and greenhouses in Switzerland. To identify potential introduction pathways and ensure appropriate phytosanitary measures and management strategies, accurate detection and identification tools are needed. Therefore, two real-time quantitative polymerase chain reaction (PCR) assays based on the second intergenic spacer region of the ribosomal DNA cistron and the cytochrome oxidase c subunit I (COI) gene using locked nucleic acid probes were developed and validated for fast and reliable detection and identification of M. enterolobii. Analytical specificity was confirmed with 16 M. enterolobii populations, 16 populations of eight closely related Meloidogyne spp., and four species from other nematode genera. Optimizing and testing the assays on two real-time PCR platforms revealed an analytical sensitivity of one juvenile in a background of 1,000 nematodes and the intended limit of detection of one juvenile per 100 ml of soil. Both assays performed equally well, with the COI-based assay showing a slightly better performance concerning detection of M. enterolobii target DNA in complex DNA backgrounds. PMID:25775103

  6. Sisal leaf decortication liquid residue for controlling Meloidogyne javanica in tomato plants / Resduo lquido do desfibramento de folhas de sisal no controle de Meloidogyne javanica em tomateiro

    Josilda CA, Damasceno; Ana CF, Soares; Fbio N, Jesus; Rosane S, Sant' Ana.

    2015-06-01

    Full Text Available Este trabalho teve o objetivo de avaliar o efeito do resduo lquido (fresco e fermentado) de sisal no controle de Meloidogyne javanica em tomateiro. Foram conduzidos bioensaios in vitro com 100 L de suspenso aquosa contendo 300 juvenis (J2) de M. javanica e 1000 L de resduo lquido. Os tratamen [...] tos consistiram do resduo lquido fresco e fermentado, nas concentraes de 2,5, 5, 7,5, 10, 12,5, 15, 17,5 e 20%, o controle sem resduo e o nematicida Carbofuran a 350 mg/L do i.a., com a imerso dos J2 nestes tratamentos, por 24 e 48 horas. Em casa de vegetao, 4000 juvenis de M. javanica foram inoculados em tomateiro e, aps uma semana, foram vertidos na base da planta 100 mL do resduo lquido de sisal nas concentraes de 0, 4, 8, 12, 16 e 20%, alm da gua destilada e o nematicida Carbofuran a 0,50 g por vaso, como testemunhas. Foram analisados o crescimento vegetativo e os danos nas razes. Avaliou-se a seletividade do resduo do sisal sobre micro-organismos benficos do solo. Todas as concentraes do resduo apresentaram efeito nematicida nos testes in vitro, aps 48 horas de exposio dos nematoides, ocorrendo at 100% de mortalidade dos juvenis de M. javanica na concentrao de 20%. O aumento das concentraes do resduo fresco ou fermentado reduziu o nmero de galhas e massas de ovos por planta e por grama de razes e tambm a populao final de M. javanica no solo. Houve crescimento dos micro-organismos benficos nos tratamentos com resduo fresco de sisal, para todas as concentraes avaliadas. O resduo fermentado inibiu o crescimento de micro-organismos benficos do solo. Estudos futuros sero conduzidos visando comprovar a ao nematicida deste resduo no controle de M. javanica em tomateiro a campo. Abstract in english The effect of sisal liquid residue (fresh and fermented) was evaluated in controlling the root-knot nematode (Meloidogyne javanica) in tomato plants. Bioassays were conducted in vitro with 100 L of an aqueous suspension containing 300 juveniles (J2) of M. javanica and 1000 L of sisal liquid residu [...] e. The treatments consisted of nematode immersion for 24 and 48 hours in sisal liquid residue, fresh or fermented, diluted in water to the final concentrations of 0, 2.5, 5, 7.5, 10, 12.5, 15, 17.5 and 20%, and nematicide Carbofuran at 350 mg of the active ingredient per liter. Under greenhouse conditions, 4000 juveniles of M. javanica were inoculated on tomato plants grown in pots, and after one week, 100 mL of sisal liquid residue at concentrations of 0, 4, 8, 12, 16 and 20%, were added to soil around the tomato plants. Control treatments received either 100 mL of distilled water or 0.5 g of Carbofuran per pot. Forty days after inoculation, plants were harvested and evaluated for plant growth and root damage. In addition, the selective effect of sisal liquid residue on growth of beneficial soil microorganisms was evaluated. All concentrations of sisal liquid residue presented nematicidal effect, after 48 h of nematode exposure. A mortality rate of 100% was obtained for M. javanica juveniles exposed to liquid residue at a concentration of 20%. Application of increasing concentrations of both sisal liquid residues reduced the number of galls and egg masses per plant and per gram of roots, as well as the final population of M. javanica in soil. Growth of beneficial soil microorganisms was observed in soil amended with sisal fresh liquid residue, for all concentrations tested. The fermented residue caused inhibition of soil beneficial microorganisms. Future studies should be conducted to test the nematicidal effect on tomato plants under field conditions.

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

    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 designing quarantine implementation, resistance breeding programmes or molecular diagnostic. PMID:19393769

  8. Nematicide Effect of Various Organic Soil Amendments on Meloidogyne ethiopica Whitehead, 1968, on Potted Vine Plants Efecto Nematicida de Varias Enmiendas Orgnicas Sobre Meloidogyne ethiopica Whitehead, 1968, en Plantas de Vid en Macetas

    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 realiz un experimento en macetas con plantas enraizadas de Vitis vinfera L. var. Chardonnay para evaluar el efecto nematicida de diferentes enmiendas orgnicas sobre el nematodo agallador Meloidogyne ethiopica Whitehead, 1968. Se usaron dos composts inmaduros: Compost A, elaborado con residuos de t (Camellia sinensis (L. Kuntze, guano de pollo seco y orujo de uva; Compost B, elaborado con residuos de t, escobajo y orujo de uva; y separadamente residuos slidos de t; orujo de uva y guano de pollo seco. Estas enmiendas fueron aplicadas a principio de primavera, tanto en cobertera como incorporadas al suelo, considerando adems un testigo qumico fenamiphos y un testigo absoluto. Se determin la poblacin de nematodos de segundo estado juvenil (estado infestivo de Meloidogyne spp., la cantidad de ndulos, huevos por gramo de raz y el ndice reproductivo, determinando de esta manera la tasa de reproduccin de los nematodos. Adems se evalu el peso fresco de la parte area y de la masa radical. El testigo qumico fue el tratamiento que obtuvo menor poblacin final de Meloidogyne spp., y al evaluar la actividad nematicida de las enmiendas orgnicas, el Compost A incorporado al suelo, orujo de uva en cobertera y residuos slidos de t en cobertera obtuvieron ndices reproductivos bajos, que no fueron estadsticamente diferentes del testigo qumico. En el peso fresco de la parte area no hubo diferencias significativas. El peso fresco de la masa radical del testigo qumico present el valor ms bajo comparado con los tratamientos de Compost B en cobertera y residuos slidos de t en cobertera.

  9. Host Status of Crotalaria juncea, Sesamum indicum, Dolichos lablab, and Elymus glaucus to Meloidogyne javanica.

    Araya, M; Caswell-Chen, E P

    1994-12-01

    Reproduction of Meloidogyne javanica on Crotalaria juncea PI 207657 and cv. Tropic Sun, Sesamum indicum, Dolichos lablab, and Elymus glaucus was assessed using a root-gall index, a reproductive index obtained by dividing the final population of juveniles (J2) in soil by the initial J2 population (Pf/Pi), and the number of J2 per gram of root recovered from roots by mist chamber extraction. Lycopersicon esculentum (cv. UC 204 C) was included as a susceptible host. The root-gall index and soil reproductive index were poor indicators of the host status of our test plants as compared with mist chamber extraction of J2 from roots. Lycopersicon esculentum had a mean root-gall index of 7.8. Some plants of S. indicum and E. glaucus had a few galls and other plants had none, with mean root-gall indices of 1.6 and 0.8, respectively. No galls were observed in C. juncea and D. lablab. Lycopersicon esculentum had the highest mean soil Pf/Pi value (mean = 1.93), while in C. juncea and some replicates of S. indicum no soil J2 were found. Even though some replicates had no galls, all replicates supported nematode reproduction. The mean numbers of J2 per gram root after 5 days of mist extraction were 447.7, 223.3, 165.5, 96.9, 42.3, and 41.9 for D. lablab, L. esculentum, E. glaucus, S. indicum, and C. juncea PI 207657 and cv. Tropic Sun, respectively. Accurate assessment of nematode resistance was influenced by sampling time and the nematode extraction technique used. Individual plants of both C. juncea and S. indicum supported nematode reproduction to some extent; however, both C. juncea and S. indicum have potential as cover crops to reduce M. javanica numbers. PMID:19279920

  10. Grafting guava on cattley guava resistant to Meloidogyne enterolobii / Enxertia da goiabeira sobre araazeiros resistentes a Meloidogyne enterolobii

    Renata Rodrigues, Robaina; Graziella Siqueira, Campos; Cludia Sales, Marinho; Ricardo Moreira, Souza; Cntia Aparecida, Bremenkamp.

    Full Text Available O uso de porta-enxertos resistentes poder ser um mtodo promissor para o controle do nematoide Meloidogyne enterolobii em plantios comerciais de goiaba, em caso de compatibilidade de enxertia. O presente trabalho teve como objetivo avaliar o pegamento via enxertia por garfagem de topo em fenda chei [...] a, entre a goiabeira e acessos de araazeiros resistentes a M. enterolobii. Os tratamentos foram constitudos pelos porta-enxertos utilizados, araazeiros (trs acessos de Psidium cattleyanum) e a goiabeira. O delineamento estatstico adotado foi em blocos casualizados (DBC), com quatro tratamentos, cinco repeties, e oito plantas por parcela. Aps a enxertia, foi avaliada a percentagem de pegamento dos enxertos. As mudas produzidas foram plantadas no campo e avaliadas quanto ao crescimento inicial das diferentes combinaes. Constatou-se pegamento de enxertia entre a goiabeira 'Paluma' e os porta-enxertos de goiabeira e araazeiros dos acessos 115 e 117, ocorrendo uma taxa de pegamento de 63, 32 e 29%, respectivamente. No campo, os araazeiros utilizados como porta-enxertos induziram menor desenvolvimento de copa e resultaram em morte de plantas. A incompatibilidade entre a goiabeira 'Paluma' e o porta-enxerto P. cattleyanum foi confirmada um ano aps plantio no campo. Abstract in english The use of resistant rootstocks could be a promising method to control nematode Meloidogyne enterolobii in 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 treat [...] ments 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. cattleyanum as rootstocks for P. guajava Paluma was confirmed one year after cultivation in field.

  11. Grafting guava on cattley guava resistant to Meloidogyne enterolobii

    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.

  12. Parasitism of Trichoderma on Meloidogyne javanica and role of the gelatinous matrix

    Trichoderma (T. asperellum-203, 44 and GH11; T. atroviride-IMI 206040 and T. harzianum-248) parasitism on Meloidogyne javanica life stages was examined in vitro. Conidium attachment and parasitism differed among the various fungi. Egg masses, their derived eggs and second-stage juveniles (J2) were p...

  13. HOST STATUS OF MELOIDOGYNE FLORIDENSIS ON SELECTED WEEDS AND COVER CROPS COMMON TO FLORIDA

    Meloidogyne floridensis was recently described as a new species of root-knot nematode infecting peach (Prunus persica) in Florida USA. This nematode is of particular importance because it reproduces on root-knot nematode resistant peach rootstocks, namely ‘Guardian’, ‘Nemaguard’, ‘Nemared’, and ‘Ok...

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

    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 defense in plants represents a potentially useful alternative for the management of M. exigua in coffee plantations. In a first assay, the present work aimed at evaluating hatching and mortality of second stage juveniles (J2 of M. exigua in solutions of acibenzolar-S-metil (ASM, Bion® and salicylic acid (SA at the dosages of 0.2, 0.35 and 0.5 g. of a. i./L and Supa-potássio® (potassium silicate, Hortifós® PK (potassium phosphite at the dosages 5.0; 7.5 and 10.0 mL/L, using water and aldicarb as control. The effect of ASM (0.2 g of a.i./L was also evaluated by foliar and drench applications at 7 days before inoculation and at 2 and 7 days after inoculation of 7000 eggs of M. exigua/plant. The hatching of M. exigua J2 was inhibited in potassium silicate and in salicylic acid solutions independent of the used dosage, while J2 hatching in ASM and water was equal and significantly lower than J2 hatching verified in potassium phosphite. The mortality of J2 in SA was next to 100% and equal to the observed in aldicarb (500 ppm. The remaining products caused the same mortality of J2, however lesser than the observed in water. At ninety days of the inoculation of M. exigua on seedlings, the final population (number of eggs + J2, number of galls, reproduction factor (final population/initial population and fresh weight of roots of plants treated with ASM did not differed significantly from control (inoculated plants.

  15. Dicty_cDB: VFD505 [Dicty_cDB

    Full Text Available VF (Link to library) VFD505 (Link to dictyBase) - - - Contig-U01356-1 VFD505P (Link to Original ... 74794.1 ra97g03.y1 Meloidogyne incognita egg pAMP1 Bird ... Meloidogyne incognita cDNA 5' similar to TR:Q9XV04 ... 73715.1 ra85b05.y1 Meloidogyne incognita egg pAMP1 Bird ... Meloidogyne incognita cDNA 5' similar to TR:Q9XV04 ...

  16. Dicty_cDB: VFH250 [Dicty_cDB

    Full Text Available VF (Link to library) VFH250 (Link to dictyBase) - - - Contig-U15170-1 VFH250P (Link to Original ... 82482.1 rb02b12.y1 Meloidogyne incognita egg pAMP1 Bird ... Meloidogyne incognita cDNA 5' similar to SW:YR44_C ... 74872.1 ra98f07.y1 Meloidogyne incognita egg pAMP1 Bird ... Meloidogyne incognita cDNA 5' similar to SW:YR44_C ...

  17. Dicty_cDB: VFD705 [Dicty_cDB

    Full Text Available VF (Link to library) VFD705 (Link to dictyBase) - - - Contig-U01356-1 VFD705P (Link to Original ... 74794.1 ra97g03.y1 Meloidogyne incognita egg pAMP1 Bird ... Meloidogyne incognita cDNA 5' similar to TR:Q9XV04 ... 73715.1 ra85b05.y1 Meloidogyne incognita egg pAMP1 Bird ... Meloidogyne incognita cDNA 5' similar to TR:Q9XV04 ...

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

    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.

  19. Reproduction of Meloidogyne enterolobii in lettuce cultivars of the American group / Multiplicao de Meloidogyne enterolobii em cultivares de alface do grupo americano

    rika CSS, Correia; Norberto, Silva; Marylia GS, Costa; Silvia RS, Wilcken.

    2015-06-01

    Full Text Available A alface a principal hortalia folhosa cultivada no Brasil, tanto em volume como em valor comercializado. Em reas de cultivo, a alface tem a sua produtividade comprometida por diversas enfermidades, incluindo as causadas pelos nematoides-das-galhas (Meloidogyne spp). Este trabalho teve como objet [...] ivo avaliar o potencial reprodutivo de Meloidogyne enterolobii em vinte e duas cultivares de alface do tipo americana. As plantas foram inoculadas com 5.000 ovos e eventuais juvenis de segundo estdio de M. enterolobii por vaso, dois dias aps o transplante das cultivares. O tomateiro 'Rutgers' foi utilizado como padro de viabilidade do inculo de M. enterolobii. Foram avaliados o ndice de galhas (IG), ndice de massas de ovos (IMO) e fator de reproduo (FR) do nematoide, aos 60 dias aps a inoculao. As cultivares Ithaca, Raider Plus, RS-1397, L-104, Challenge, IP-11, Classic, Salinas 88, Vanguard 75, Calona e Desert Queen apresentaram resistncia a M. enterolobii, com FR variando de 0,22 a 0,9, e as cultivares Lady, Winterset, Robinson, Sonoma, Raider, Lucy Brown, Bnondaga, Summer Time, Tain, Sundevil e L-109 foram suscetveis a esse nematoide, com FR variando de 1,06 a 5,73. Abstract in english Lettuce is the main vegetable cultivated in Brazil, in volume and in marketed value. There are ranges of diseases which may affect lettuce crops, including those caused by root-knot nematodes (Meloidogyne spp.). We evaluated the reproductive potential of Meloidogyne enterolobii in 22 lettuce cultiva [...] rs. The plants were inoculated with 5,000 eggs and eventuals second stage juveniles of nematode per pot, two days after the transplanting. 'Rutgers' tomato was used as standard for inoculum viability of M. enterolobii. We evaluated, 60 days after inoculation, the gall index, egg mass index and reproduction factor (RF). The 'Ithaca', 'Raider Plus', 'RS-1397', 'L-104', 'Challenge', 'IP-11', 'Classic', 'Salinas 88', 'Vanguard 75', 'Calona' and 'Desert Queen' were resistant to M. enterolobii with RF varying from 0.22 to 0.9, and the cultivars Lady Winterset, Robinson, Sonoma, Raider, Lucy Brown, Bnondaga, Summer Time, Taina, Sundevil and L-109 were susceptible to this nematode, with RF ranging from 1.06 to 5.73.

  20. Description and SEM Observations of Meloidogyne sasseri n. sp. (Nematoda: Meloidogynidae), Parasitizing Beachgrasses

    Handoo, Zafar A.; Huettel, Robin N.; Golden, A. Morgan

    1993-01-01

    Meloidogyne sasseri n. sp. is described and illustrated from American beachgrass (Ammophila breviliffulata) originally collected from Henlopen State Park and Fenwick Island near the Maryland state line in Delaware, United States (6). Its relationship to M. graminis, M. spartinae, and M. californiensis is discussed. Primary distinctive characters of the female perineal pattern were a high to rounded arch with shoulders, widely spaced lateral lines interrupting transverse striations, a sunken v...

  1. Meloidogyne enterolobii n. sp. (Meloidogynidae), a Root-knot Nematode Parasitizing Pacara Earpod Tree in China

    Yang, Baojun; Eisenback, J.D.

    1983-01-01

    Meloidogyne enterolobii n. sp. is described and illustrated from roots of pacara earpod tree, Enterolobium contortisiliquum (Vell.) Morong, on Hainan Island in China. The perineal pattern of the female is usually oval shaped, the striae are fine to coarse, the dorsal arch is moderately high to high and usually rounded, and the phasmids are large. The stylet knobs in females are divided longitudinally by a groove so that each knob appears as two. The mean distance of the excretory pore to the ...

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

    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 et...

  3. Host Range and Distribution of the Clover Root-knot Nematode, Meloidogyne trifoliophila

    Bernard, E. C.; Jennings, P. L.

    1997-01-01

    The ability of Meloidogyne trifoliophila to gall 230 species and cultivars of plants was determined in a greenhouse. All clovers (Trifolium spp.) were severely galled regardless of species or cultivar. Most soybean cultivars were moderately to severely galled. Among other legumes, broad bean, garden pea, Korean lespedeza, sweetclover, and common vetch were good hosts, but alfalfa, bird's-foot trefoil, peanut, and pole bean were poor or nonhosts. Among other plant families, most Apiaceae (Umbe...

  4. Management of Root Knot Disease in Rice Caused by Meloidogyne graminicola through Nematophagous Fungi

    Sobita Simon; Anamika Anamika

    2011-01-01

    A glass house experiment was conducted for the effectiveness of nematophagous fungi against Meloidogynegraminicola in which Arthrobotrys oligospora and Dactylaria eudermata were used for the management of rootknot disease of rice. Root knot nematodes, Meloidogyne graminicola had proved itself as an important limitingfactor for successful cultivation and productivity of rice. By amending the soil with application of mass cultureof two nematophagous fungi (Arthrobotrys oligospora and Dactylaria...

  5. Rotations of Bahiagrass and Castorbean with Peanut for the Management of Meloidogyne arenaria

    Rodríguez-Kábana, R.; Robertson, D. G.; Weaver, C. F.; Wells, L.

    1991-01-01

    The relative value of 'Hale' castorbean (Ricinus communis) and 'Pensacola' bahiagrass (Paspalum notatum) as rotational crops for the management of Meloidogyne arenaria and southern blight (Sclerotium rolfsii) in 'Florunner' peanut (Arachis hypogaea) production was studied for 3 years in a field experiment in southeast Alabama. Peanut following 2 years of castorbean (C-C-P) yielded 43% higher than monocultured peanut without nematicide. At-plant application of aldicarb (30.5 g a.i./100 m row i...

  6. Relationship Between Levels of Cyanide in Sudangrass Hybrids Incorporated into Soil and Suppression of Meloidogyne hapla

    Widmer, T. L.; Abawi, G. S.

    2002-01-01

    Sudangrass cv. Trudan 8 has been demonstrated to suppress infection of vegetables by Meloidogyne hapla (Mh). Hydrogen cyanide, released from the degradation of the cyanogenic glucoside (dhurrin) during decomposition of Trudan 8, was the primary factor involved in suppression of Mh on vegetables. The cyanide ion level in leaf tissue of 14 hybrids of sudangrass varied between 0.04 (cv. SX-8) to 1.84 parts per million (cv. 840F). The suppressive activity of the sudangrass hybrids against Mh was ...

  7. Control of Meloidogyne chitwoodi in Potato with Fumigant and Nonfumigant Nematicides

    Ingham, R. E.; Hamm, P. B.; Williams, R.E.; Swanson, W. H.

    2000-01-01

    During 1993-94, several fumigant and nonfumigant nematicides were tested alone and in combination at various rates for control of Columbia root-knot nematode (Meloidogyne chitwoodi) in potato. Ethoprop, oxamyl, or metam sodium alone did not adequately reduce tuber infection. Metam sodium plus ethoprop reduced culled tubers to 3%, and metam sodium plus 2 or 3 foliar applications of oxamyl reduced culls to ≤10% in all but one instance. Fosthiazate provided excellent control of tuber infection w...

  8. Suitable rootstocks for organically grown tomato and cucumber in relation to Meloidogyne SPP.

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

    2011-01-01

    In organic greenhouse vegetable production, significant yield loss occurs due to root-knot nematodes (Meloidogyne spp.). Soil steaming is effective; however, it is not preferred, since beneficial soil micro organisms are eliminated. An inclusion of resistant hosts within the crop rotation is complicated by the broad host range of the nematode and the high level of specialization of companies towards production of fruit vegetables. Nearly all species of fruit vegetables are susceptible to a va...

  9. Penetration of Crotalaria juncea, Dolichos lablab, and Sesamum indicum Roots by Meloidogyne javanica

    Araya, M.; Caswell-Chen, E.P.

    1994-01-01

    Penetration of Crotalaria juncea (PI 207657 and cv. Tropic Sun) Dolichos lablab cv. Highworth, and Sesamum indicum by juveniles (J2) of Meloidogyne javanica was assessed to investigate the mechanism by which these plants may reduce nematode numbers in the field. Growth chamber experiments were conducted at 25 C, with vials containing 90 g sand infested with 450 J2; tomato (UC 204 C) was included as a susceptible host. Fifteen days after inoculation, roots were stained and the nematodes within...

  10. Histopathogenesis of susceptibe and resistant responses of wheat, barley and wild grasses to Meloidogyne naasi

    Balhadre, P.; Evans, A.A.F.

    1995-01-01

    Les ractions des gramines sauvages #Aegilops variabilis$ et #Hordeum chilense$, plantes totalement rsistantes au nmatode galles #Meloidogyne naasi$, sont compares en microscopie optique aux ractions de deux varits sensibles de crales, #Triticum aestivum$ cv. Chinese Spring et #Hordeum vulgare$ cv. Doublet, ainsi qu' la raction du cv. d'orge partiellement rsistant, Morocco. Dans ces deux premiers cas, la rsistance totale fait intervenir de faon trs prcoce des ractions de ty...

  11. Effects of Solarization and Ammonium Amendments on Plant-Parasitic Nematodes

    McSorley, R.; McGovern, R. J.

    2000-01-01

    The effects of soil solarization and ammonium bicarbonate or ammonium sulfate against plant-parasitic nematodes on yellow squash (Cucurbita pepo) and on vinca (Catharanthus roseus) were evaluated at two sites. Solarization for 3 weeks in the spring suppressed population levels of Belonolaimus longicaudatus, Criconemella spp., and Dolichodorus heterocephalus throughout the growing season on both crops at both sites. Levels of Meloidogyne incognita were suppressed initially, but population dens...

  12. [Evaluation of the resistance to two nematodes: Radopholus similis and Meloidogyne spp. in four banana genotypes in Morocco].

    Guedira, Abdelkarim; Rammah, Abdellah; Triqui, Zine-el-abidine; Chlyah, Hassan; Chlyah, Bouchra; Haïcour, Robert

    2004-08-01

    Radopholus similis and Meloidogyne spp. are the main nematode parasites of banana plants grown under plastic shelters in Morocco. A test was made in pots to evaluate the resistance of four genotypes of banana to these nematodes. Infection by Meloidogyne spp. brought about an increase in root weight in all banana plants tested because of gall formation. The inoculation of R. similis produced a reduction in length and diameter of the pseudo-trunk as well as in root and aerial mass in all genotypes. Pisang jari buaya showed the significantly lowest number of Meloidogyne nematodes per 10 g of roots, whereas for R. similis, the significantly smallest numbers were obtained in Pisang berlin and Pisang jari buaya. Therefore, Pisang jari buaya was the only banana genotype studied to show some degree of resistance to both nematodes. PMID:15506523

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

    Alexandre Macedo Almeida; Ricardo Moreira de Souza; Vicente Martins Gomes; Guilherme Bessa Miranda

    2012-01-01

    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 la...

  14. Effect of Cutting Age on the Resistance of Prunus cerasifera (Myrobalan Plum) to Meloidogyne arenaria

    Esmenjaud, D.; Minot, J. C.; Voisin, R; Salesses, G.; Bonnet, A

    1995-01-01

    The response of softwood cuttings of Myrobalan plum infested after 50 and 105 days with 3,000 second-stage juveniles (J2) of Meloidogyne arenaria was compared to 15-month-old hardwood cuttings in 13 genotypes ranging from highly resistant to susceptible. Gall index and number of galls were recorded 30 days after infestation. Fifty-day-old cuttings rooted in perlite developed many rootlets, but had only incipient galls after infestation. In sand, rooting of 50-day-old cuttings not treated with...

  15. Meloidogyne haplanaria n. sp. (Nematoda: Meloidogynidae), a Root-knot Nematode Parasitizing Peanut in Texas

    Eisenback, J. D.; Bernard, E. C.; Starr, J. L.; Lee, T. A.; Tomaszewski, E. K.

    2003-01-01

    Meloidogyne haplanaria n. sp. is described and illustrated from specimens parasitizing peanut in Texas. The perineal pattern of the female is rounded to oval with a dorsal arch that is high and rounded except for striae near the vulva, which are low with rounded shoulders. The striae are distinctly forked in the lateral field, and punctations often occur as a small group near the tail tip and singly within the whole perineal pattern. The female stylet is 13-16 µm long and has broad, distinctl...

  16. Efecto de diferentes densidades poblacionales de meloidogyne hapla sobre uchuva (physalis peruviana l.) en invernadero

    Niño, Nancy Eunice; Arbeláez, Germán; Navarro, Rafael

    2010-01-01

    Este estudio se realizó en el Centro de Investigaciones y Asesorías Agroindustriales de la Universidad de Bogotá Jorge Tadeo Lozano, Chía (Cundinamarca), bajo condiciones de invernadero, durante diez meses de cultivo. Se evaluó el efecto de diferentes densidades poblacionales de Meloidogyne hapla (0, 50, 100, 200, 500 y 1.000 larvas J2/100 cc de suelo), sobre parámetros productivos de la uchuva: altura de las plantas, diámetro de tallo, peso fresco, peso seco y biomasa de follaje, pes...

  17. Effect of the Mi Gene in Tomato on Reproductive Factors of Meloidogyne chitwoodi and M. hapla

    Brown, C. R.; Mojtahedi, H.; Santo, G. S.; Williamson, V.M.

    1997-01-01

    The effect of the Mi gene on the reproductive factor of Meloidogyne chitwoodi and M. hapla, major nematode pests of potato, was measured on nearly isogenic tomato lines differing in presence or absence of the Mi gene. The Mi allele controlled resistance to reproduction of race 1 of M. chitwoodi and to one of two isolates of race 2. No resistance to race 3 of M. chitwoodi or to M. hapla was found. Variability in response to isolates of race 2 may reflect diversity of virulence genotypes hereto...

  18. An investigation into the potential of crude and partially separated material of selected non-crop plant species as control agents of root-knot nematodes (Meloidogyne incognita) in tomato / Mbokota Candy Khosa

    Khosa, Mbokota Candy

    2012-01-01

    Plant-parasitic nematodes (PPN) are a serious problem in vegetable production and can cause severe damage to several crops. In rural, low-input farming nematode damage is much higher and yields can be completely destroyed. Some Commercial nematicides have been withdrawn from the market due to health and environment concerns. These need to be replaced by alternative nematode control strategies of which soil amendments is one alternative. Nine non-crop plant species used in vario...

  19. Survey of Nematodes on Coffee in Hawaii

    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 ...

  20. Resistance to Root-knot, Reniform, and Soybean Cyst Nematodes in Selected Soybean Breeding Lines

    Davis, E.L.; Meyers, D. M.; Burton, J W; Barker, K.R.

    1998-01-01

    Soybean breeding lines and reported sources of nematode resistance were evaluated in repeated greenhouse tests for resistance to North Carolina populations of the soybean cyst nematode Heterodera glycines, reniform nematode Rotylenchulus reniformis, and the root-knot nematode species Meloidogyne incognita, M. arenaria, and M. arenaria. Lines from the soybean breeding program in Missouri that had 'Hartwig' soybean as a parent were the most resistant to races 1-4 of the soybean cyst nematode an...

  1. Differential Response to Root-Knot Nematodes in Prunus Species and Correlative Genetic Implications

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

    1997-01-01

    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 ...

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

    Seddigheh Fatemy

    2016-03-01

    Full Text Available 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.

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

    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 mencionada no trabalho anterior, bem como metabólitos na forma bruta de Fusarium moniliforme Shelden e Cylindrocarpon magnusianum (Sacc. Woll., produzidos em meio de cultura líquido, foram submetidos a testes in vitro com juvenis do segundo estádio (J2 de M. exigua. Todas as plantas e fungos produziram substâncias ativas contra J2. Portanto, seus metabólitos foram aplicados em mudas de café de seis meses de idade, inoculadas com M. exigua. Após 90 dias em casa de vegetação, verificou-se que os materiais oriundos de A. cepa, L. leucocephala, R. graveolens e F. moniliforme inibiram a produção de ovos e de galhas por M. exigua, demonstrando potencial para o controle de tal parasita.

  4. Reação de aceroleira (Malpighia emarginata D.C. à Meloidogyne enterolobii

    José Carlos Cavichioli

    2014-03-01

    Full Text Available O Brasil é o maior produtor, consumidor e exportador de acerola (Malpighia emarginata D.C. do mundo. Por conter altos teores de vitamina C, tornou-se uma fruta altamente requisitada no mercado mundial para o preparo de sucos e no consumo in natura. Nos últimos anos, as lavouras desta fruta vêm apresentando um decréscimo nas produções em razäo da ocorrência de nematoides de galhas (Meloidogyne spp., um dos principais problemas que afetam a cultura. O objetivo deste trabalho foi avaliar a resistência de genótipos de aceroleira frente à Meloidogyne enterolobii. O experimento foi conduzido em casa de vegetação do Departamento de Proteção Vegetal, da Faculdade de Ciências Agronômicas/UNESP - Câmpus de Botucatu (SP. Foram utilizados cinco clones: Cereja-Brs-236; Fruta Cor- Brs-238; Roxinha-Brs-237; Mirandópolis; Japi, e três variedades: Okinawa; Olivier e Waldy-CATI. Cada planta foi inoculada com 2.500 ovos e eventuais juvenis de segundo estádio (Pi de M. enterolobii. Após 60 dias, a parte área de cada planta foi descartada, e o sistema radicular lavado, submetido à coloração com floxina-B e examinado para a obtenção dos índices de galhas (IG e massa de ovos (IMO, e processados pelo método de trituração em liquidificador, peneiramento e centrifugação com sacarose para a obtenção do número total de ovos (Pf, que foi utilizado para o cálculo do fator de reprodução (Pf/Pi. Todos os clones e as variedades foram considerados suscetíveis à Meloidogyne enterolobii apresentando os fatores de reprodução variando de 4,1 a 18,3.

  5. The role of seaweed extracts, Ascophyllum nodosum, in the reduction in fecundity of Meloidogyne javanica

    Whapham, C.A.; Jenkins, T.; Blunden, G.; Hankins, S.D.

    1994-01-01

    Les effets d'extraits commerciaux de l'algue marine #Ascophyllum nodosum$ sur la fécondité du nématode #Meloidogyne javanica$, élevé sur tomate (#Lycopersicon esculentum$ cv. Ailsa Craig) sont évalués. Après une génération, le nombre d'oeufs du nématode récupérés sur les plantes traitées diminue considérablement en comparaison avec les plantes témoins, traitées avec de l'eau pure. Un plus faible nombre d'oeufs sont récupérés sur les plantes infestées par des juvéniles ayant incubé dans des e...

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

    Vanessa dos Santos Paes-Takahashi; Pedro Luiz Martins Soares; Franciele Alves Carneiro; Rivanildo Junior Ferreira; Eduardo José de Almeida; Jaime Maia dos Santos

    2015-01-01

    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 macho...

  7. HERANÇA DA RESISTÊNCIA DE MILHO A MELOIDOGYNE JAVANICA

    SAWAZAKI EDUARDO; LORDELLO ANA INES LUCENA; LORDELLO RUBENS RODOLFO ALBUQUERQUE

    1998-01-01

    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,...

  8. Nematicidal effect of volatile organic compounds (VOCs on the plant-parasitic nematode Meloidogyne javanica

    Mauricio Batista Fialho

    2012-06-01

    Full Text Available Previous studies have demonstrated that volatile organic compounds (VOCs, produced by the yeast Saccharomyces cerevisiae, were able to inhibit the development of phytopathogenic fungi. In this context, the nematicidal potential of the synthetic mixture of VOCs, constituted of alcohols and esters, was evaluated for the control of the root-knot nematode Meloidogyne javanica, which causes losses to crops of high economic value. The fumigation of substrate containing second-stage juveniles with VOCs exhibited nematicidal effect higher than 30% for the lowest concentration tested (33.3 L g-1 substrate, whereas at 66.6 and 133.3 L g-1 substrate, the nematode mortality was 100%. The present results stimulate other studies on VOCs for nematode management.

  9. Effects of different inoculum densities of Trichoderma harzianum and Trichoderma viride against Meloidogyne javanica on tomato.

    Al-Hazmi, Ahmad Saad; TariqJaveed, Muhammad

    2016-03-01

    A greenhouse experiment was conducted to evaluate the effects of different inoculum densities of two Saudi isolates of Trichoderma harzianum and Trichoderma viride against Meloidogyne javanica on tomato. Four densities (10(4), 10(6), 10(8) and 10(10) spores/g of soil) of each fungus were used. The results indicate that all four inoculum densities of the two Trichoderma species suppressed the nematode reproduction and root galling; and increased the growth of tomato plants, compared to controls. Efficacy of both fungi increased as their inoculum densities increased. Generally, efficacy of T. harzianum was better than that of T. viride, especially at the highest used density (10(10) spore/g soil) which resulted in the best control. PMID:26981012

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

    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)

  11. 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

    Lucia Rivera; Erwin Aballay

    2008-01-01

    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 app...

  12. Mitochondrial coding genome analysis of tropical root-knot nematodes (Meloidogyne) supports haplotype based diagnostics and reveals evidence of recent reticulate evolution.

    Janssen, Toon; Karssen, Gerrit; Verhaeven, Myrtle; Coyne, Danny; Bert, Wim

    2016-01-01

    The polyphagous parthenogenetic root-knot nematodes of the genus Meloidogyne are considered to be the most significant nematode pest in sub-tropical and tropical agriculture. Despite the crucial need for correct diagnosis, identification of these pathogens remains problematic. The traditionally used diagnostic strategies, including morphometrics, host-range tests, biochemical and molecular techniques, now appear to be unreliable due to the recently-suggested hybrid origin of root-knot nematodes. In order to determine a suitable barcode region for these pathogens nine quickly-evolving mitochondrial coding genes were screened. Resulting haplotype networks revealed closely related lineages indicating a recent speciation, an anthropogenic-aided distribution through agricultural practices, and evidence for reticulate evolution within M. arenaria. Nonetheless, nucleotide polymorphisms harbor enough variation to distinguish these closely-related lineages. Furthermore, completeness of lineage sorting was verified by screening 80 populations from widespread geographical origins and variable hosts. Importantly, our results indicate that mitochondrial haplotypes are strongly linked and consistent with traditional esterase isozyme patterns, suggesting that different parthenogenetic lineages can be reliably identified using mitochondrial haplotypes. The study indicates that the barcode region Nad5 can reliably identify the major lineages of tropical root-knot nematodes. PMID:26940543

  13. Entomopathogenic Nematodes and Bacteria Applications for Control of the Pecan Root-Knot Nematode, Meloidogyne partityla, in the Greenhouse

    Shapiro-Ilan, David I.; Nyczepir, Andrew P.; Lewis, Edwin E.

    2006-01-01

    Meloidogyne partityla is a parasite of pecan and walnut. Our objective was to determine interactions between the entomopathogenic nematode-bacterium complex and M. partityla. Specifically, we investigated suppressive effects of Steinernema feltiae (strain SN) and S. riobrave (strain 7–12) applied as infective juveniles and in infected host insects, as well as application of S. feltiae's bacterial symbiont Xenorhabdus bovienii on M. partityla. In two separate greenhouse trials, the treatments ...

  14. Plant Sources of Chinese Herbal Remedies: Laboratory Efficacy, Suppression of Meloidogyne javanica in Soil, and Phytotoxicity Assays

    Zasada, I. A.; Ferris, H.; Zheng, L.

    2002-01-01

    Extracts of Chinese herbal medicines from plants representing 13 families were tested for their ability to suppress plant-parasitic nematodes. Effective concentration (EC50 and EC90) levels for 18 of the extracts were determined in laboratory assays with Meloidogyne javanica juveniles and all stages of Pratylenchus vulnus. Efficacy of 17 extracts was tested against M. javanica in soil. Generally, EC50 and EC90 values determined in the laboratory were useful indicators for application rates in...

  15. Effect of Inhibitors and Stimulators of Ethylene Production on Gall Development in Meloidogyne javanica-Infected Tomato Roots

    Glazer, Itamar; Apelbaum, Akiva; Orion, Daniel

    1985-01-01

    Excised tomato roots infected with Meloidogyne javanica produced ethylene at 3-6 times the rate of noninfected roots. This increase in ethylene production started 5 days after inoculation. Gall growth and ethylene production in infected roots were accelerated by 1-aminocyclopropane-1-carboxylic acid (ACC), indole acetic acid (IAA), and ethrel known as ethylene production stimulators. When inhibitors of ethylene production, like aminoethoxyvinylglycine (AVG) or aminoxyacetic acid (AOA), or inh...

  16. Interrelationships between Ethylene Production, Gall Formation, and Root-knot Nematode Development in Tomato Plants Infected with Meloidogyne javanica

    Giazer, I.; Orion, D; Apelbaum, A.

    1983-01-01

    Ethylene production was determined in excised tomato (Lycopersicon esculentum) root cultures of Meloidogyne javanica susceptible and resistant cultivars infected with M. javanica. Uninfected cultivars produced very low amounts of ethylene. Relatively high amounts of ethylene were produced by the infected susceptible cultivars. Peak production of 1.6 n moles * g root? * h? occurred between 9 and 16 days after inoculation (DAI). The period of high ethylene production coincided with that of ra...

  17. Effect of Culture Filtrate of Fungi in the Control of Meloidogyne javacnica, Root Knot Nematodes on Okra and Broad Bean

    Amer-Zareen

    1999-01-01

    Full Text Available Fungal cell free filtrates were used in two different doses, enhanced plant growth and root knot nematodes infection was reduced where high doses of filtrate (100% concentration were applied, in all test fungal filtrates. Culture filtrates of Paecilomyces lilacinus and Verticillium chlamydosporium at 100 percent concentration showed significant reduction in Meloidogyne javanica root knot infection on okra and broad bean as compared to Trichoderma harzianum, T. koningii, T. viride, Aspergillus restrictus and Aspergillus sp., which found less effective.

  18. INVESTIGATION OF ENDOPHYTIC FUNGI Trichoderma sp. IN FORM OF POWDER AND DIFFERENT DOSES AGAINST ROOT-KNOT NEMATODE Meloidogyne spp.

    25.Nur, Amin

    2015-01-01

    The term ???endophytes??? includes a suite of microorganisms that grow intra-and/or intercelullarly in the tissues of higher plants without causing over symptoms on the plants in which they live, and have proven to be rich sources of bioactive natural products. Root-knot nematodes Meloidogyne spp are serious pests of many cultivated crops around the word and is estimated economic losses around US $ 100 billion annually. A Greenhouse experiment was conducted in five treatment (Doses) of endoph...

  19. A metabolomic approach to study the rhizodeposition in the tritrophic interaction: tomato, Pochonia chlamydosporia and Meloidogyne javanica

    Escudero Benito, Nuria; Marhuenda Egea, Frutos Carlos; Ibanco-Caete, Ricardo; Zavala Gonzlez, E.A.; Lpez Llorca, Luis Vicente

    2014-01-01

    A combined chemometrics-metabolomics approach [excitationemission matrix (EEM) fluorescence spectroscopy, nuclear magnetic resonance (NMR) and high performance liquid chromatographymass spectrometry (HPLCMS)] was used to analyse the rhizodeposition of the tritrophic system: tomato, the plant-parasitic nematode Meloidogyne javanica and the nematode-egg parasitic fungus Pochonia chlamydosporia. Exudates from M. javanica roots were sampled at root penetration (early) and gall development (lat...

  20. Comparison of saline tolerance among genetically similar species of Fusarium and Meloidogyne recovered from marine and terrestrial habitats

    Elmer, W. H.; LaMondia, J. A.

    2014-08-01

    Successful plant pathogens co-evolve and adapt to the environmental constraints placed on host plants. We compared the salt tolerance of two salt marsh pathogens, Fusarium palustre and Meloidogyne spartinae, to genetically related terrestrial species, F. sporotrichioides and Meloidogyne hapla, to assess whether the salt marsh species had acquired selective traits for persisting in saline environments or if salt tolerance was comparable among Fusarium and Meloidogyne species. Comparisons of both species were made in vitro in vessels containing increasing concentration of NaCl. We observed that F. palustre was more tolerant to NaCl than F. sporotrichioides. The radial expansion of F. palustre on NaCl-amended agar plates was unaffected by increasing concentrations up to 0.3 M. F. sporotrichioides showed large reductions in growth at the same concentrations. Survival of M. hapla was greatest at 0 M, and reduced by half in a 0.3 M solution for 4 days. No juveniles survived exposure to 0.3 M NaCl for 12 days. M. spartinae survived at all NaCl concentrations tested, including 1.0 M for at least 12 days. These findings are consistent with the hypothesis that marine organisms in the upper tidal zone must osmoregulate to withstand a wide range of salinity and provide evidence that these pathogens evolved in saline conditions and are not recent introductions from terrestrial niches.

  1. First Report of Northern Root-Knot Nematode, Meloidogyne hapla, Parasitic on Oaks, Quercus brantii and Q. infectoria in Iran.

    Sohrabi, Effat; Maafi, Zahra Tanha; Panahi, Parisa; Barooti, Shapour

    2015-03-01

    Root-knot nematodes (RKN) are the most serious plant parasitic nematodes having a broad host range exceeding 2,000 plant species. Quercus brantii Lindl. and Q. infectoria Oliv are the most important woody species of Zagros forests in west of Iran where favors sub-Mediterranean climate. National Botanical Garden of Iran (NBGI) is scheduled to be the basic center for research and education of botany in Iran. This garden, located in west of Tehran, was established in 1968 with an area of about 150 ha at altitude of 1,320 m. The Zagros collection has about 3-ha area and it has been designed for showing a small pattern of natural Zagros forests in west of Iran. Brant's oak (Q. brantii) and oak manna tree (Q. infectoria) are the main woody species in Zagros collection, which have been planted in 1989. A nematological survey on Zagros forest collection in NBGI revealed heavily infection of 24-yr-old Q. brantii and Q. infectoria to RKN, Meloidogyne hapla. The roots contained prominent galls along with egg sac on the surface of each gall. The galls were relatively small and in some parts of root several galls were conjugated, and all galls contained large transparent egg masses. The identification of M. hapla was confirmed by morphological and morphometric characters and amplification of D2-D3 expansion segments of 28S rRNA gene. The obtained sequences of large-subunit rRNA gene from M. hapla was submitted to the GenBank database under the accession number KP319025. The sequence was compared with those of M. hapla deposited in GenBank using the BLAST homology search program and showed 99% similarity with those KJ755183, GQ130139, DQ328685, and KJ645428. The second stage juveniles of M. hapla isolated from Brant's oak (Q. Brantii) showed the following morphometric characters: (n = 12), L = 394 39.3 (348 to 450) m; a = 30.9 4 (24.4 to 37.6); b = 4.6 0.44 (4 to 5.1); b? = 3.3 0.3 (2.7 to 3.7), c = 8.0 1 (6.2 to 10.3), ? = 5.3 0.8 (3.5 to 6.3); Stylet = 12.1 0.8 (11 to 13) m; Tail = 50 5.6 (42 to 57) m; Hyaline 15 1.8 (12 to 18) m. Oak manna, Q. infectoria population of second stage juveniles clearly possessed short body length and consequently other morphometric features were less than those determined for Q. brantii population, and these features were: (n = 12), L = 359.0 17.3 (319 to 372) m; a = 28.6 3 (22.8 to 31); b = 5.0 0.3 (4.8 to 5.2); b? = 3.3 0.2 (3 to 3.6), c = 8.1 0.5 (7.4 to 8.8), ? = 4.7 0.5 (3.9 to 5.2); Stylet = 11.4 0.7 (10 to 12) m; Tail = 44 1.8 (42 to 47) m; Hyaline 12 1.7 (10 to 15) m. To date two species of Meloidogyne, M. quercianaGolden, 1979 and M. christieiGolden and Kaplan, 1986 have been reported to parasitize oaks (Quercus spp.) from the United States of America. M. querciana was found on pin oak Quercus palustris in Virginia. The oak RKN infected pine oak, red oak, and American chestnut heavily in greenhouse tests (Golden, 1979). The other species M. christiei was described from turkey oak and Q. laevis in Florida, which has monospecific host range (Golden and Kaplan, 1986). Both of these RKN species seem to be restricted to the United States of America and have not been reported from other place. According to our knowledge this is the first report of occurrence of M. hapla on Q. brantii and Q. infectoria in the world. This study includes these two oak species to the host range of RKN, M. hapla for the world and expands the information of RKN, M. hapla host ranges on oaks. PMID:25861121

  2. Alterações anatômicas induzidas por Meloidogyne enterolobii (=M. mayaguensis e Meloidogyne javanica em tomateiros resistentes a meloidoginose

    Juliana Nogueira Westerich

    2012-09-01

    Full Text Available A resistência de tomateiros (Solanum lycopersicum L. a M. incognita, M. javanica e M. arenaria, conferida pela presença do gene Mi, não contempla a espécie M. enterolobii (=M. mayaguensis. O objetivo da pesquisa foi verificar as alterações anatômicas causadas por M. enterolobii no sistema radicular de porta-enxertos de tomateiro com o gene de resistência Mi ('Magnet' e Helper M' e compará-las com as causadas por M. javanica. As observações anatômicas das raízes foram feitas com auxílio de microscópio de luz e os aspectos mais relevantes foram fotografados. Com base em contagens e mensurações do tamanho dos sítios de alimentação e das células gigantes, foram efetuadas analises utilizando o método estatístico de Análise de Agrupamento. O aparecimento de células nutridoras incitadas por M. enterolobii foi verificado em ambos os porta-enxertos de tomateiro, entre 10 e 17 dias após a inoculação (DAI. O número e a área de sítios de alimentação e de células gigantes foram menores aos 17 DAI do que aos 24 DAI. Nesta época (24 DAI, foram observados sítios de alimentação constituídos pela presença de várias células nutridoras multinucleadas, com parede celular espessa, citoplasma denso e granuloso. Os tecidos vasculares apresentaram-se comprimidos e desorganizados, foi observada, também, hipertrofia de células do parênquima cortical. As raízes inoculadas com M. javanica não apresentaram alterações anatômicas.

  3. Molecular dissection of the rDNA array and of the 5S rDNA gene in Meloidogyne artiellia: phylogenetic and diagnostic implications.

    Veronico, Pasqua; De Luca, Francesca; De Giorgi, Carla

    2004-06-01

    The sequence of a 13.423 nucleotide genomic fragment has been determined for the plant parasitic nematode Meloidogyne artiellia. It contains an entire rDNA cluster, the bordering intergenic regions and portions of the flanking coding regions. The sequence analysis of the rDNA repeats suggests homogeneity in M. artiellia, thus providing a further indication of the usefulness of these genes for the diagnostic identification of this species. The comparison of the secondary structures of the internal transcribed spacer 2 region in several Meloidogyne species indicates that RNA folding predictions can be used as a tool of potential diagnostic relevance. The other ribosomal gene, 5S rDNA, has been demonstrated to be functional and located near the trans-spliced leader sequences, in the same arrangement found in the distantly related nematode Caenorhabditis elegans but never in other Meloidogyne thus providing species-specific markers for the identification of several Thylenchida parasitic nematodes. PMID:15135452

  4. Relationship Between Meloidogyne hapla Density and Damage to Carrots in Organic Soils.

    Vrain, T C

    1982-01-01

    Field and growth chamber experiments were conducted to determine the effect of five initial densities (Pi - 20 - 240/100 cm(3) soil) of Meloidogyne hapla on carrot development and yield of storage roots at maturity. Carrots growing in infested and noninfested organic soil were harvested after 15, 29, 44, 59, and 106 days of growth in controlled environment chambers and after l l 0 days in field plots. Nematodes affected weight of roots and foliage, weight and length of the storage portion of tap roots, and induced malformations (forking), galling, and hairiness of tap roots. In most cases the data could not be represented satisfactorily by the exponential model of Seinhorst: y = m + (l-m) Z(P-t). In growth chambers the weight of mature storage roots was not correlated to initial nematode density, but there was a significant negative correlation between weight of storage roots and initial nematode density in field plots. Tolerance levels were calculated as points where the regression lines reached the growth level on noninoculated plants. The tolerance levels of foliage were higher than those of roots, and increased with age of plants. The tolerance level of marketable weight in field plots, average crop value, and a hypothetical control cost function are used to discuss the possibility of optimizing chemical control of root-knot nematode in organic soils. PMID:19295674

  5. Meloidogyne enterolobii n. sp. (Meloidogynidae), a Root-knot Nematode Parasitizing Pacara Earpod Tree in China.

    Yang, B; Eisenback, J D

    1983-07-01

    Meloidogyne enterolobii n. sp. is described and illustrated from roots of pacara earpod tree, Enterolobium contortisiliquum (Vell.) Morong, on Hainan Island in China. The perineal pattern of the female is usually oval shaped, the striae are fine to coarse, the dorsal arch is moderately high to high and usually rounded, and the phasmids are large. The stylet knobs in females are divided longitudinally by a groove so that each knob appears as two. The mean distance of the excretory pore to the anterior end in the female is 62.9 mum. Males have a large, rounded labial disc that fuses with the medial lips to form a dorso-ventrally elongate head cap. The labial disc is slightly elevated, and the medial lips are crescent shaped. The second-stage juvenile mean body length is 436.6 mum. The lateral lips are large and triangular in face view. The tail is 56.4 mum long and narrow with a broad, bluntly rounded tip. M. enterolobii n. sp reproduces well on E. contortisiliquum and causes severe damage. Other good hosts include cotton, resistant tobacco 'NC 95,' pepper, watermelon, and tomato. PMID:19295822

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

    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

    2013-09-01

    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

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

    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.

  8. The nematicidal effect of camellia seed cake on root-knot nematode Meloidogyne javanica of banana.

    Yang, Xiujuan; Wang, Xuan; Wang, Kang; Su, Lanxi; Li, Hongmei; Li, Rong; Shen, Qirong

    2015-01-01

    Suppression of root-knot nematodes is crucially important for maintaining the worldwide development of the banana industry. Growing concerns about human and environmental safety have led to the withdrawal of commonly used nematicides and soil fumigants, thus motivating the development of alternative nematode management strategies. In this study, Meloidogyne javanica was isolated, and the nematicidal effect of Camellia seed cake on this pest was investigated. The results showed that in dish experiments, Camellia seed cake extracts under low concentration (2 g/L) showed a strong nematicidal effect. After treatment for 72 h, the eggs of M. javanica were gradually dissolved, and the intestine of the juveniles gradually became indistinct. Nematicidal compounds, including saponins identified by HPLC-ESI-MS and 8 types of volatile compounds identified by GC-MS, exhibited effective nematicidal activities, especially 4-methylphenol. The pot experiments demonstrated that the application of Camellia seed cake suppressed M. javanica, and promoted the banana plant growth. This study explored an effective nematicidal agent for application in soil and revealed its potential mechanism of nematode suppression. PMID:25849382

  9. Description of the Kona Coffee Root-knot Nematode, Meloidogyne konaensis n. sp.

    Eisenback, J D; Bernard, E C; Schmitt, D P

    1994-12-01

    Meloidogyne konaensis n. sp. is described from coffee from Kona on the island of Hawaii. The perineal pattern of the female is variable in morphology, the medial lips of the female are divided into distinct lip pairs, and the excretory pore is 2-3 stylet lengths from the base of the stylet. Mean stylet length is 16.0 mum, and the knobs gradually merge with the shaft. The knobs are indented anteriorly and rounded posteriorly and the dorsal esophageal gland orifice (DEGO) is long, 3.5-7 mum. The morphology of the stylet of the male is the most useful diagnostic character, with 6-12 large projections protruding from the shaft. One medial lip may be divided into distinct lip pairs. A large intestinal caecum often extends nearly to the level of the DEGO. Mean juvenile length is 502 mum, mean stylet length is 13.4 mum, and mean tail length is 58 mum. The tail may be distinctly curved ventrally and the phasmids are located in the ventral incisure about one anal body width posterior to the anus. PMID:19279905

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

    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.

  11. Fungi and actinomycetes associated with Meloidogyne spp. eggs and females in China and their biocontrol potential.

    Sun, Man-Hong; Gao, Li; Shi, Yan-Xia; Li, Bao-J; Liu, Xing-Zhong

    2006-09-01

    A survey was conducted to determine the microflora on eggs and females of Meloidogyne spp. collected from plant roots and infested soil in China. A total of 455 fungal isolates belonging to 24 genera and 52 isolates of actinomycetes were obtained from 28 samples from greenhouses and fields in Hainan, Yunnan, Fujian, Hebei, Shandong, and Beijing. The predominant fungal species were Paecilomyces lilacinus (49.3% of the isolates), Fusarium spp. (7.9%), Pochonia chlamydosporia (6.9%), Penicillium spp. (5.7%), Aspergillus spp. (3.2%), and Acremonium spp. (2.8%). Actinomycetes were frequently encountered (10.3%) as well. A total of 350 isolates of nematophagous fungi and actinomycetes were evaluated for their parasitism of eggs and effects on egg hatch and juvenile mortality in vitro. Pathogenicity varied among isolates, and 29.1% of isolates parasitized over 90% eggs 4 days after inoculation. Results also show that seven isolates of fungi and actinomycetes reduced egg hatch rates to less than 10% contrasted to the control of 65.8%, and three isolates killed all hatched juveniles after 7 days. Seventeen fungal isolates and four actinomycete isolates with high pathogenicity in vitro were selected to test biocontrol efficacy in the greenhouse. They reduced tomato root gall index by 13.4-58.9% compared to the no treatment control. PMID:16737708

  12. Penetration of Crotalaria juncea, Dolichos lablab, and Sesamum indicum Roots by Meloidogyne javanica.

    Araya, M; Caswell-Chen, E P

    1994-06-01

    Penetration of Crotalaria juncea (PI 207657 and cv. Tropic Sun) Dolichos lablab cv. Highworth, and Sesamum indicum by juveniles (J2) of Meloidogyne javanica was assessed to investigate the mechanism by which these plants may reduce nematode numbers in the field. Growth chamber experiments were conducted at 25 C, with vials containing 90 g sand infested with 450 J2; tomato (UC 204 C) was included as a susceptible host. Fifteen days after inoculation, roots were stained and the nematodes within stained roots were counted. Both C. juncea lines were highly resistant to penetration, as they contained significantly fewer nematodes per cm of root and per root system than the other plants. Although containing more nematodes per cm of root than C. juncea, S. indicum and D. lablab had significantly fewer nematodes per root system and per cm of root than tomato. Roots were significantly longer in the plants with the lowest nematode penetration. Although C. juncea, D. lablab, and S. indicum may have potential utility as cover or rotation crops in soil infested with M. javanica, further quantitative information on the reproduction of M. javanica and other nematodes in these plants is needed. PMID:19279887

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

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

    2016-01-01

    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, 105, 106, 107, and 108 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 108 conidia/ml suspension, respectively. PMID:27168653

  14. Chitosan enhances parasitism of Meloidogyne javanica eggs by the nematophagous fungus Pochonia chlamydosporia.

    Escudero, Nuria; Ferreira, Sebastião R; Lopez-Moya, Federico; Naranjo-Ortiz, Miguel A; Marin-Ortiz, Ana I; Thornton, Christopher R; Lopez-Llorca, Luis V

    2016-04-01

    Pochonia chlamydosporia (Pc), a nematophagous fungus and root endophyte, uses appressoria and extracellular enzymes, principally proteases, to infect the eggs of plant parasitic nematodes (PPN). Unlike other fungi, Pc is resistant to chitosan, a deacetylated form of chitin, used in agriculture as a biopesticide to control plant pathogens. In the present work, we show that chitosan increases Meloidogyne javanica egg parasitism by P. chlamydosporia. Using antibodies specific to the Pc enzymes VCP1 (a subtilisin), and SCP1 (a serine carboxypeptidase), we demonstrate chitosan elicitation of the fungal proteases during the parasitic process. Chitosan increases VCP1 immuno-labelling in the cell wall of Pc conidia, hyphal tips of germinating spores, and in appressoria on infected M. javanica eggs. These results support the role of proteases in egg parasitism by the fungus and their activation by chitosan. Phylogenetic analysis of the Pc genome reveals a large diversity of subtilisins (S8) and serine carboxypeptidases (S10). The VCP1 group in the S8 tree shows evidence of gene duplication indicating recent adaptations to nutrient sources. Our results demonstrate that chitosan enhances Pc infectivity of nematode eggs through increased proteolytic activities and appressoria formation and might be used to improve the efficacy of M. javanica biocontrol. PMID:27020158

  15. Effect of Soil Water Potential on Survival of Meloidogyne javanica in Fallow Soil.

    Towson, A J; Apt, W J

    1983-01-01

    A natural infestation of Meloidogyne javanica in an aggregated Oxisol declined at an exponential rate when aliquots of the soil were stored for 72 days in polyethylene bags at various soil water potentials (Psi). Time periods required for reduction in soil infestations by 50% were 2.7, 4.9, 110, 10, and 2.6 days at Psi of -0.16, -0.30, -1.1, -15, and -92 bars, respectively. In the wetter soils, at Psi of -0.16, -0.30, and -1.1 bars, the predominant stage recovered was the second-stage larva. In the drier soils, at Psi of -15 and -92 bars, both eggs and larvae were recovered with neither stage predominating. Incidence of coiled larvae was inversely related to the Psi value of the soil, a greater incidence occurring in the drier soils. After 15-32 days, percentages of coiled larvae were 13, 27, 55, 65, and 88% in soil at Psi of -0.17, -0.60, -1.9, -15, and -82 bars, respectively. PMID:19295774

  16. Seleção de isolados de Paecilomyces lilacinus (Thom.) Samson para controle de Meloidogyne paranaensis em tomateiro Selection of isolates of Paecilomyces lilacinus (Thom.) Samson to control Meloidogyne paranaensis in tomato

    Débora Cristina Santiago; Martin Homechin; João Flávio Veloso Silva; Emerson Rodrigo Ribeiro; Bruno Caetano Gomes; Patrícia Helena Santoro

    2006-01-01

    Paecilomyces lilacinus é uma espécie fúngica utilizada no controle biológico de nematóides, sendo uma das mais estudadas a campo. O trabalho teve como objetivo selecionar isolados de Paecilomyces lilacinus quanto à capacidade de controlar Meloidogyne paranaensis em tomateiro cv. "Santa Clara", em de casa-de-vegetação. Plantas cultivadas em vasos foram inoculadas com M. paranaensis. Após 45 dias da inoculação, efetuou-se a substituição dos tomateiros e foram aplicados 50 gramas de arroz autocl...

  17. Variabilidade gentica de acessos de araazeiro e goiabeira suscetveis e resistentes a Meloidogyne enterolobii / Genetic variability of araa and guava accessions susceptible and resistant Meloidogyne enterolobii

    Aline das Graas, Souza; Luciane Vilela, Resende; Isabela Pereira de, Lima; Rosimar Musser dos, Santos; Nilton Nagib Jorge, Chalfun.

    2014-05-01

    Full Text Available A goiabeira representa uma importante atividade frutcola no Brasil, com mercado cada vez maior. Porm, desde 1989 vm sendo relatados severos danos cultura, causados pelo nematide Meloidogyne enterolobii. Uma das alternativas para solucionar esse problema a utilizao de porta-enxertos com res [...] istncia a este patgeno. Este trabalho teve por objetivo a caracterizao molecular, com marcadores RAPD, de acessos de Psidium testados quanto resistncia a M. enterolobii e quanto compatibilidade como porta-enxertos para as goiabeiras comerciais. Foram testados 30 primers, dos quais 19 forneceram resultados ntidos para a amplificao. Foram gerados 163 fragmentos, dos quais 86 polimrficos (63,0%). Em mdia, cada iniciador produziu 8,6 fragmentos, dos quais 5,4 apresentaram polimorfismo. A anlise de agrupamento foi realizada por espcie, os acessos de Psidium sp apresentaram a formao de dois grupos, um formado pelo acesso A-UFLA e o segundo subdividido em quatro subgrupos, sendo os acessos com maiores distncias genticas A-Ufla, resistente a M. enterolobii, A-Ufla4 e A-Ufla5, ambos suscetveis ao nematoide em questo, todos coletados em Lavras-MG, com similaridade aproximada de 66%. Na anlise de agrupamento, dos treze acessos de P.cattleyanum, foi possvel constatar a formao de dois grandes grupos. Um formado por trs acessos suscetveis a M. enterolobii (A-20.2, A-10.1 e A-9.2) e outro grupo formado por dez acessos. Os acessos se agruparam, conforme a regio de origem, em seis grupos, sendo que o mais divergente originrio da regio de Lavras - MG, com 0,65 de similaridade, onde as distncias genticas variaram de 0,88 a 0,65. Dos treze acessos de P. guineense, todos suscetveis a M. enterolobii, sendo 12 oriundos de Recife e um de Pelotas (A-14.1) e agruparam-se em dois grupos com similaridades variando de 0,59 a 0,83. Quanto ao estudo de diversidade entre os acessos de goiabeiras, a maior distncia gentica foi detectada entre o acesso G-Ufla com 0,71 Lavras-MG. Abstract in english Guava culture stands for an important fruit-growing business in Brazil, with a greater and greater market. But, since 1989 severe damages to the culture caused by the nematode Meloidogyne enterolobii, have been reported. One the alternatives to solve this problem is the use of rootstocks with resist [...] ance to this nematode. This research aimed at the molecular characterization, with RAPD markers, of Psidium accessions susceptible to be utilized as rootstocks for the commercial guava trees. 30 primers were tested, from which 19 supplied distinct results for the amplification. The primers generated 163 polymorphic marks, resulting into a mean of 8,6 polymorphic bands per primer. The cluster analysis was performed per species, the accessions of Psidium sp presented the formation of two groups, one formed by A-UFLA accession and the other subdivided into four subgroups, that is, the accession with increased genetic distances, A-Ufla, resistant to M. enterolobii, A-Ufla4 and A-Ufla5, both susceptible to the nematode in issue, all collected in Lavras-MG with a similarity of about 66%. In the cluster analysis of the thirteen accessions of P.cattleyanum, it was possible to found the formation of two great groups. One made up by three accessions susceptible to M. enterolobii (A-20.2, A-10.1 and A-9.2) and the other group formed by ten accessions. The accessions grouped together according to the region of origin in six groups, the most divergent being that native to region of Lavras - MG, with 0.65 of similarity, where the genetic distances ranged from 0.88 to 0.65. The thirteen accessions of P. guineense, all susceptible to M. enterolobii, namely, 12 coming from Recife and one proceeding from Pelotas (A-14.1), grouped themselves together and two groups with similarity ranging from 0.59 to 0.83. As to the diversity study among the guava tree accessions, the greatest genetic distances were detected between the accessions G.P.S and G-Ufla with 0,71 Lavras-MG.

  18. Reação de genótipos e híbridos de tomateiro à Meloidogyne enterolobii

    Juliana Magrinelli Osório Rosa; Juliana Nogueira Westerich; Silvia Renata Siciliano Wilcken

    2014-01-01

    A meloidoginose tem sido considerada uma das mais importantes doenças da cultura do tomate. O uso de tomateiros resistentes ao nematoide das galhas é medida bastante utilizada no controle de diferentes espécies, entretanto, a reação de tomateiros à Meloidogyne enterolobii ainda é pouco conhecida. Portanto, objetivou-se a determinação da reprodução de M. enterolobii em dez híbridos de tomate (Absoluto, Cascade, Cordillera, Donatto, Ellen, Fascínio, Laura, Marguerita, Nícolas e Sanni) e dois ge...

  19. Fast assembly of the mitochondrial genome of a plant parasitic nematode (Meloidogyne graminicola) using next generation sequencing

    Besnard, G.; Juhling, F.; Chapuis, Elodie; Zedane, L.; Lhuillier, E.; Mateille, Thierry; Bellafiore, Stéphane

    2014-01-01

    Little is known about the variations of nematode mitogenomes (mtDNA). Sequencing a complete mtDNA using a PCR approach remains a challenge due to frequent genome reorganizations and low sequence similarities between divergent nematode lineages. Here, a genome skimming approach based on HiSeq sequencing (shotgun) was used to assemble de novo the first complete mtDNA sequence of a root-knot nematode (Meloidogyne graminicola). An AT-rich genome (84.3%) of 20,030 bp was obtained with a mean seque...

  20. Levantamento de Meloidogyne exigua na cultura da seringueira em São José do Rio Claro, MT, Brasil

    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.

  1. Seleção de isolados de Paecilomyces lilacinus (Thom.) Samson para controle de Meloidogyne paranaensis em tomateiro

    Santiago Débora Cristina; Homechin Martin; Silva João Flávio Veloso; Ribeiro Emerson Rodrigo; Gomes Bruno Caetano; Santoro Patrícia Helena

    2006-01-01

    Paecilomyces lilacinus é uma espécie fúngica utilizada no controle biológico de nematóides, sendo uma das mais estudadas a campo. O trabalho teve como objetivo selecionar isolados de Paecilomyces lilacinus quanto à capacidade de controlar Meloidogyne paranaensis em tomateiro cv. "Santa Clara", em de casa-de-vegetação. Plantas cultivadas em vasos foram inoculadas com M. paranaensis. Após 45 dias da inoculação, efetuou-se a substituição dos tomateiros e foram aplicados 50 gramas de arroz autocl...

  2. Ocorrência de Meloidogyne enterolobii (sin. M. mayaguensis em pomares de goiabeira no município de Ivinhema, Estado de Mato Grosso do Sul

    Héber Ferreira dos Reis

    2011-06-01

    Full Text Available Este trabalho relata uma ocorrência de Meloidogyne enterolobii (sin. M. mayaguensis no Estado do Mato Grosso do Sul, parasitando goiabeira (Psidium guajava, cv. Novo Milênio. O nematoide foi caracterizado e identificado pelo fenótipo da isoenzima esterase (Est (Est M2, Rm: 0,7 e 0,9.

  3. Effects of the Mi-1, N and Tabasco Genes on Infection and Reproduction of Meloidogyne Mayaguensis on Tomato and Pepper Genotypes

    Meloidogyne mayaguensis is a damaging root-knot nematode that is able to reproduce on root-knot nematode-resistant tomato and other economically important crops. In a growth chamber experiment conducted at 22 and 33 C, isolate 1 of M. mayaguensis reproduced at both temperatures on the Mi-1-carrying...

  4. Respuesta de Zamia incognita L. al cultivo in vitro, una alternativa para su conservación

    Aura I. Urrea

    2012-08-01

    Full Text Available Título en ingles: In vitro culture response on Zamia incognita,  an alternative for preservation Resumen: Las Zamiaceas son plantas relictuales consideradas fósiles vivientes. En Colombia, el 65% de esta familia se encuentra en alguna categoría de amenaza, por la destrucción del hábitat e intensa recolección. Teniendo en cuenta que entre las ventajas de la propagación in vitro está la conservación ex situ de germoplasma, el presente trabajo tuvo como objetivo evaluar el potencial de regeneración de plantas de Z. incognita a partir de explantes foliares y embriones cigoticos. Se evaluó el efecto de diferentes combinaciones de Auxinas (2,4-D y ANA y citoquininas (KIN, BAP y TDZ sobre la formación de callo  y la regeneración de brotes (directa o indirecta, utilizando como medio basal MS (MB1 y medio basal B5 modificado (MB2. La formación de callo se presentó sobre un amplio rango de concentraciones de 2,4-D con KIN y 2,4-D con BAP, independientemente del medio basal, pero no en los explantes tratados con ANA más KIN o TDZ.  Para los explantes foliares no hubo respuesta  a la formación de embriones somáticos y/o brotes con las combinaciones y concentraciones hormonales evaluadas, no obstante los callos inducidos en MB2 con 2,4-D (0,22 mg/l y BAP (0, 1, 2, 3 mg/l fueron diferentes, su aspecto nodular, color crema y  apariencia proembriogénica coincidió con una gran cantidad de células meristemáticas potenciales para el proceso de regeneración. A partir de embriones cigoticos inmaduros se logró la formación de embriones somáticos en el medio MB2 exento de reguladores o conteniendo 2,4-D solo (0,22 mg/l y en combinación con BAP (1 mg/l, sin lograr el proceso de conversión a plántulas. Palabras clave: micropropagación; hojas jóvenes; reguladores de crecimiento; embriones cigóticos; medio basal. Abstract: Zamiaceas are relict plants considered living fossils. In Colombia, 65% of this family is under some threat category due to their habitat destruction and their intense collection. Given that the advantages of in vitro propagation is ex situ conservation of germoplasm, this study aimed to evaluate the regeneration potential of  Z incognita plants  from leaf explants and zygotic embryos. The effect of different combinations of auxin (2.4-D and NAA and cytokinins (KIN, BAP and TDZ was evaluated on the formation of callus and shoot regeneration (direct or indirect, using MS (MB1 basal medium and B5 (MB2 basal modified medium.  The callus formation was presented over a wide concentration range of 2.4-D with KIN and 2.4-D with BAP, regardless of the basal medium, but not in explants treated with ANA more TDZ or KIN. For leaf explants there was no response to the formation of somatic embryos or shoots with hormonal combinations and concentrations evaluated; however, MB2 calluses induced with 2.4-D (0.22 mg / l and BAP (0. 1 , 2. 3 mg / l were different, their nodular aspect, cream color and pro-embryogenic appearance coincided with a lot of potential meristematic cells for the regeneration process. From immature zygotic embryos, somatic embryo formation in the MB2 medium was achieved without growth regulators or containing 2.4-D alone (0.22 mg /l or 2.4-D in combination with BAP (1 mg/l without achieving the conversion process to seedlings. Key words: microprogation; young leaves; plant growth regulators; zygotic embryos; basal medium.

  5. Controle de Meloidogyne javanica em mudas de bananeira 'prata-an' por compostos orgnicos

    Bruna Hanielle Carneiro dos Santos

    2013-06-01

    Full Text Available O trabalho teve como objetivo avaliar o efeito de compostos orgnicos no controle de Meloidogyne javanica, e no desenvolvimento de mudas de bananeiras 'Prata-An. O experimento foi conduzido em DIC, com dez repeties, e os tratamentos consistiram em quatro compostos constitudos de diferentes matrias-primas (restos da cultura da banana, cana-de-acar, esterco bovino, cascas de banana, plantas daninhas, capim andropogon, o esterco bovino, a torta de mamona e testemunhas (adubao mineral, carbofuran e testemunha absoluta (sem adio de composto orgnico. Em cada vaso, foram colocados 3 kg de solo autoclavado, incorporado com cada um dos tratamentos avaliados e inoculado com suspenso contendo 4.000 ovos de M. javanica. Aps quatro dias, transplantou-se uma muda de bananeira 'Prata-An' micropropagada, e aos 60 dias, avaliaram-se: altura das plantas, dimetro, nmero de folhas e peso de matria seca da parte area, e nmero de galhas, massas de ovos, nmero de ovos e o nmero de juvenis de segundo estdio (J2, por 100 cm de solo. Testou-se in vitro o efeito das fraes hmicas dos quatro compostos (que no causaram fitotoxidez e esterco bovino sobre a mortalidade e motilidade de J2 de M. javanica. O ensaio foi montado em placas de ELISA em DIC, com cinco repeties. Os compostos orgnicos e o esterco bovino aumentaram o desenvolvimento das mudas. A torta de mamona provocou efeito fitotxico s mudas. Menor nmero de variveis nematolgicas foi proporcionado pela torta de mamona e pelo carbofuran. O nmero de J2 tambm foi menor nas parcelas tratadas com carbofuran e tambm pelo Composto 3, constitudo por plantas daninhas+restos de cana-de-acar+ esterco bovino e pelo adubo mineral. Para o teste in vitro, as substncias hmicas conferiram efeito nematicida e nematosttico. Dentre os compostos, o C3 mostrou-se promissor por reduzir o desenvolvimento do nematoides e no apresentar efeito fitotxico.

  6. Hawksbill turtle terra incognita: conservation genetics of eastern Pacific rookeries.

    Gaos, Alexander R; Lewison, Rebecca L; Liles, Michael J; Gadea, Velkiss; Altamirano, Eduardo; Henríquez, Ana V; Torres, Perla; Urteaga, José; Vallejo, Felipe; Baquero, Andres; LeMarie, Carolina; Muñoz, Juan Pablo; Chaves, Jaime A; Hart, Catherine E; Peña de Niz, Alejandro; Chácon, Didiher; Fonseca, Luis; Otterstrom, Sarah; Yañez, Ingrid L; LaCasella, Erin L; Frey, Amy; Jensen, Michael P; Dutton, Peter H

    2016-02-01

    Prior to 2008 and the discovery of several important hawksbill turtle (Eretmochelys imbricata) nesting colonies in the EP (Eastern Pacific), the species was considered virtually absent from the region. Research since that time has yielded new insights into EP hawksbills, salient among them being the use of mangrove estuaries for nesting. These recent revelations have raised interest in the genetic characterization of hawksbills in the EP, studies of which have remained lacking to date. Between 2008 and 2014, we collected tissue samples from 269 nesting hawksbills at nine rookeries across the EP and used mitochondrial DNA sequences (766 bp) to generate the first genetic characterization of rookeries in the region. Our results inform genetic diversity, population differentiation, and phylogeography of the species. Hawksbills in the EP demonstrate low genetic diversity: We identified a total of only seven haplotypes across the region, including five new and two previously identified nesting haplotypes (pooled frequencies of 58.4% and 41.6%, respectively), the former only evident in Central American rookeries. Despite low genetic diversity, we found strong stock structure between the four principal rookeries, suggesting the existence of multiple populations and warranting their recognition as distinct management units. Furthermore, haplotypes EiIP106 and EiIP108 are unique to hawksbills that nest in mangrove estuaries, a behavior found only in hawksbills along Pacific Central America. The detected genetic differentiation supports the existence of a novel mangrove estuary "reproductive ecotype" that may warrant additional conservation attention. From a phylogeographic perspective, our research indicates hawksbills colonized the EP via the Indo-Pacific, and do not represent relict populations isolated from the Atlantic by the rising of the Panama Isthmus. Low overall genetic diversity in the EP is likely the combined result of few rookeries, extremely small reproductive populations and evolutionarily recent colonization events. Additional research with larger sample sizes and variable markers will help further genetic understanding of hawksbill turtles in the EP. PMID:26941950

  7. Detection of plant-parasitic nematode DNA in the gut of predatory and omnivorous nematodes

    A protocol for molecular gut analysis of nematodes was developed to determine if predatory and omnivorous nematodes from five different guilds prey on Rotylenchulus reniformis, Meloidogyne incognita, and Radopholus similis. Mononchoides, Mononchus, Neoactinolaimus, Mesodorylaimus, and Aporcelaimell...

  8. Subenxertia da goiabeira 'Paluma' com araçazeiros resistentes a Meloidogyne enterolobii (sin. M. mayaguensis

    Renata Rodrigues Robaina

    2012-09-01

    Full Text Available Estudos anteriores demonstraram resistência ou imunidade ao nematoide Meloidogyne enterolobii em araçazeiros (Psidium cattleyanum Sabine, mas não foi encontrada essa resistência em goiabeiras. O objetivo deste trabalho foi avaliar a subenxertia entre a goiabeira 'Paluma' e araçazeiros, como um meio de obter goiabeiras resistentes ao nematoide. Oitenta plântulas da goiabeira 'Paluma', produzidas por estaquia, foram conduzidas em vasos de 5 litros (uma por vaso até que atingissem 8 mm à altura de 10 cm do colo para serem subenxertadas. Os subenxertos (acessos dos araçazeiros 115; 116; 117 e goiabeira foram produzidos por mudas seminíferas. Ao lado de cada muda de goiabeira 'Paluma' (copa, foram transplantadas duas mudas seminíferas de araçazeiros ou de goiabeiras. A subenxertia foi feita por um corte em bisel e introdução do subenxerto de uma das plantas laterais sob a casca da goiabeira 'Paluma'. A outra planta lateral foi despontada na mesma época e utilizada como uma testemunha. Foram efetuadas avaliações a cada 20 dias quanto ao crescimento em diâmetro do caule (da copa, do subenxerto e da testemunha. O pegamento na subenxertia da goiabeira 'Paluma' com os araçazeiros foi inferior ao pegamento observado quando o subenxerto utilizado foi a própria goiabeira. Após o pegamento, em muitos casos, a conexão vascular não foi estabelecida com sucesso e não houve estabelecimento de conexões vasculares funcionais entre alguns subenxertos produzidos com araçazeiros ou com a própria goiabeira, o que foi comprovado pela baixa sobrevivência da copa após o corte de seu sistema radicular. A subenxertia deve ser mais bem investigada para a introdução de um porta-enxerto à goiabeira.

  9. High and low throughput screens with root-knot nematodes Meloidogyne spp.

    Atamian, Hagop S; Roberts, Philip A; Kaloshian, Isgouhi

    2012-01-01

    Root-knot nematodes (genus Meloidogyne) are obligate plant parasites. They are extremely polyphagous and considered one of the most economically important plant parasitic nematodes. The microscopic second-stage juvenile (J2), molted once in the egg, is the infective stage. The J2s hatch from the eggs, move freely in the soil within a film of water, and locate root tips of suitable plant species. After penetrating the plant root, they migrate towards the vascular cylinder where they establish a feeding site and initiate feeding using their stylets. The multicellular feeding site is comprised of several enlarged multinuclear cells called 'giant cells' which are formed from cells that underwent karyokinesis (repeated mitosis) without cytokinesis. Neighboring pericycle cells divide and enlarge in size giving rise to a typical gall or root knot, the characteristic symptom of root-knot nematode infection. Once feeding is initiated, J2s become sedentary and undergo three additional molts to become adults. The adult female lays 150-250 eggs in a gelatinous matrix on or below the surface of the root. From the eggs new infective J2s hatch and start a new cycle. The root-knot nematode life cycle is completed in 4-6 weeks at 26-28°C. Here we present the traditional protocol to infect plants, grown in pots, with root-knot nematodes and two methods for high-throughput assays. The first high-throughput method is used for plants with small seeds such as tomato while the second is for plants with large seeds such as cowpea and common bean. Large seeds support extended seedling growth with minimal nutrient supplement. The first high throughput assay utilizes seedlings grown in sand in trays while in the second assay plants are grown in pouches in the absence of soil. The seedling growth pouch is made of a 15.5 x 12.5cm paper wick, folded at the top to form a 2-cm-deep trough in which the seed or seedling is placed. The paper wick is contained inside a transparent plastic pouch. These growth pouches allow direct observation of nematode infection symptoms, galling of roots and egg mass production, under the surface of a transparent pouch. Both methods allow the use of the screened plants, after phenotyping, for crossing or seed production. An additional advantage of the use of growth pouches is the small space requirement because pouches are stored in plastic hanging folders arranged in racks. PMID:22434014

  10. Strip-tilled cover cropping for managing nematodes, soil mesoarthropods, and weeds in a bitter melon agroecosystem.

    Marahatta, Sharadchandra P; Wang, Koon-Hui; Sipes, Brent S; Hooks, Cerruti R R

    2010-06-01

    A field trial was conducted to examine whether strip-tilled cover cropping followed by living mulch practice could suppress root-knot nematode (Meloidogyne incognita) and enhance beneficial nematodes and other soil mesofauna, while suppressing weeds throughout two vegetable cropping seasons. Sunn hemp (SH), Crotalaria juncea, and French marigold (MG), Tagetes patula, were grown for three months, strip-tilled, and bitter melon (Momordica charantia) seedlings were transplanted into the tilled strips; the experiment was conducted twice (Season I and II). Strip-tilled cover cropping with SH prolonged M. incognita suppression in Season I but not in Season II where suppression was counteracted with enhanced crop growth. Sunn hemp also consistently enhanced bacterivorous and fungivorous nematode population densities prior to cash crop planting, prolonged enhancement of the Enrichment Index towards the end of both cash crop cycles, and increased numbers of soil mesoarthropods. Strip-tilled cover cropping of SH followed by clipping of the living mulch as surface mulch also reduced broadleaf weed populations up to 3 to 4 weeks after cash crop planting. However, SH failed to reduce soil disturbance as indicated by the Structure Index. Marigold suppressed M. incognita efficiently when planted immediately following a M. incognita-susceptible crop, but did not enhance beneficial soil mesofauna including free-living nematodes and soil mesoarthropods. Strip-tilled cover cropping of MG reduced broadleaf weed populations prior to cash crop planting in Season II, but this weed suppression did not last beyond the initial cash crop cycle. PMID:22736847

  11. EFEITOS DE PRODUTOS QUÍMICOS NO CONTROLE DE Meloidogyne sp SOBRE QUIABEIRO (Hibiscus sculentum L. EFFECTS OF CHEMICAL CONTROL OF Meloidogyne sp. IN Hibiscus sculentum L. IN OKRA

    Lincoln Fonseca Zica

    2007-09-01

    Full Text Available

    Testou-se o poder nematicida de Shell-DD, Vapan, Nemagon granulado, brometo de metila e Neantina solúvel em solos com infestacão natural de Meloidogyne sp., usando-se o quiabeiro (Hibiscus escullentum L. como referência para medir a intensidade de infestação após o tratamento. O Shell-DD (40 ml/m² exerceu notável efeito nematicida, mas o Vapan (60 ml/m², o Nemagon granulado (40 g/m² e a Neantina solúvel (solução a 0,3% - 10 l/m² deram resultados estatisticamente iguais à testemunha. As parcelas tratadas com Brometo de metila (40 ml/m² foram perdidas em consequência do efeito fitotóxico do produto sobre as sementes e plântulas do quiabeiro.

    The nematicide power of Shell-DD, vapan, granulated nemagon, methyl bromide and soluble neantina, were tested by applying them to soil affected by Meloidogyne sp. The okra plant (Hibiscus esculentum L. was used as the hosting agent, to measure the amount of worms af-ter treatment. The results showed that Shell-DD (40 ml/m² controlled the worms well, but that vapan, granulated nemagon and the soluble neantina were statistically equal to the control plot. The plots treated with methyl bromide were not included in the results because of the toxic effect of the product on the plants.

  12. Antagonistic Effect of Some Species of Pleurotus on the Root-knot Nematode, Meloidogyne javanica in vitro

    R. Heydari

    2006-01-01

    Full Text Available Antagonistic effect of five species of Pleurotus, including P. ostreatus, P. sajor-caju, P. cornucopiae, P. florida and P. eryngii on second stage juveniles (J2 of Meloidogyne javanica were studied, in vitro. On water agar, all of the species tested produced tiny droplets of toxin. Nematodes touching such droplets showed a sudden response and became colonized by the fungi after 24-48 h. Filtrates of the tested fungi grown in malt extract broth were toxic on the nematodes but this toxicity varied between species. Culture filtrates of P. ostreatus showed the highest nematicidal activity toward M. javanica J2 and the lowest toxic effect was observed in filtrates of P. eryngii. A linear relationship was proved between increasing toxin concentration and the percentage of dead nematodes.

  13. Triagem de genótipos de hortaliças para resistência a Meloidogyne enterolobii

    Osvânder David de Melo

    2011-08-01

    Full Text Available O objetivo deste trabalho foi identificar genótipos de alface, batata-doce, feijão, tomate e Capsicum resistentes ao nematoide Meloidogyne enterolobii (Syn. M. mayaguensis e classificá-los quanto ao grau de resistência. Foram avaliados: 10 genótipos de alface, 8 de batata-doce, 10 de feijão e feijão-vagem, 25 de Capsicum e 6 de tomate. Foram calculados o fator de reprodução e o índice de reprodução, e os genótipos foram classificados quanto ao grau de resistência ao nematoide. Foram observados níveis moderados de resistência na cultivar de feijão Aporé e nos acessos de pimenta, BGH-433 e BGH-4285, e de pimentão, PIM-031, PIX-022I-31-07-02 e PIX-022I-31-13-01. Todos os genótipos de tomate são suscetíveis a M. enterolobii. As cultivares de alface Julia, Hortência, Verônica, Grand Rapids e Babá de Verão, e os clones de batata-doce UFLA07-49 e UFLA07-53 são muito resistentes ao nematoide. A resistência a M. enterolobii aparentemente é mediada por genes diferentes dos que conferem resistência a outras espécies e raças de Meloidogyne.

  14. Ectomycorrhization of Acacia holosericea A. Cunn. ex G. Don by Pisolithus spp. in Senegal: Effect on plant growth and on the root-knot nematode Meloidogyne javanica

    Duponnois, R; Founoune, H.; Bâ, A.; Plenchette, C.; El Jaafari, S.; Neyra, M.; Ducousso, M.

    2000-01-01

    Ectomycorhization de Acacia holosericea A. Cunn. ex G. Don par Pisolithus spp. au Sénégal : effet sur le développement de la plante et sur la multiplication du nématode à galles Meloidogyne javanica. L'effet de symbiotes fongiques ectomycorhiziens, appartenant au genre Pisolithus et isolés au Sénégal, a été étudié sur la croissance de plants d'Acacia holosericea et sur le développement d'un peuplement de nématodes phytoparasites Meloidogyne javanica. Une enquête a été réalisée sur 100 arbres ...

  15. Effects of the Mi-1 and the N root-knot nematode-resistance gene on infection and reproduction of Meloidogyne enterolobii on tomato and pepper cultivars

    Kiewnick, Sebastian; Dessimoz, Mireille; Franck, Lucie

    2009-01-01

    Meloidogyne enterolobii is widely considered to be an aggressive root-knot nematode species that is able to reproduce on root-knot nematode-resistant tomato and pepper cultivars. In greenhouse experiments, M. enterolobii isolates 1 and 2 from Switzerland were able to reproduce on tomato cultivars carrying the Mi-1 resistance gene as well as an N-carrying pepper cultivar. Reproduction factors (Rf) ranged between 12 and 109 depending on the plant cultivar, with M. enterolobii isolate 2 being mo...

  16. Crescimento micelial e parasitismo de Paecilomyces lilacinus sobre ovos de Meloidogyne paranaensis em diferentes temperaturas"in vitro" / "In vitro" mycelial growth and parasitism of Paecilomyces lilacinus on Meloidogyne paranaensis eggs at different temperatures

    Marina Capparelli, Cadioli; Dbora Cristina, Santiago; Adriano Thibes, Hoshino; Martin, Homechin.

    2007-04-01

    Full Text Available Paecilomyces lilacinus um fungo de solo, parasita facultativo de ovos de nematides, que pode crescer rapidamente "in vitro". Este trabalho teve como objetivo avaliar o crescimento micelial de P. lilacinus em diferentes temperaturas e selecionar os melhores isolados quanto capacidade de parasita [...] r ovos de Meloidogyne paranaensis. Foram avaliados isolados de P. lilacinus, obtidos de solos coletados na regio de Londrina, PR. Para o isolamento empregou-se a tcnica de diluio seriada dos solos e plaqueamento em meio de cultura semi-seletivo. A determinao do crescimento micelial e do parasitismo "in vitro" dos isolados sobre M. paranaensis foi realizada em placas de Petri contendo meio BDA. Os isolados foram incubados em B.O.D. a temperaturas de 20C, 22,5C, 25C, 27,5C e 30C. A avaliao do crescimento foi interrompida quando em um dos tratamentos a colnia do fungo atingiu a borda da placa de Petri e a determinao do parasitismo foi realizada depois de oito dias de incubao, calculando-se a porcentagem de ovos parasitados. O crescimento micelial dos isolados de P. lilacinus teve grande dependncia da temperatura de incubao a que foram submetidos, sendo mais rpido temperatura de 22,5C. Os isolados de P. lilacinus revelaram habilidade para infectar os ovos de M. paranaensis em meio BDA, principalmente na temperatura de 25C. Abstract in english Paecilomyces lilacinus is a soil fungus, facultative parasite of nematode eggs, which develops quickly "in vitro". The mycelial growth of P. lilacinus isolates was evaluated at different temperatures and the best isolates, regarding the capacity to parasite Meloidogyne paranaensis eggs, were chosen. [...] P. lilacinus soil isolates from Londrina, Parana state, were evaluated. Isolation was done using serial dilution of the soils and plating it in semi-selective agar medium. The determination of mycelial growth and "in vitro" parasitism of these isolates was done using Petri plates containing potato-dextrose-agar (PDA), placed in chamber at 20C, 22.5C, 25C, 27.5C or 30C. The evaluation started when in one of the treatments of the fungus colonies reached the edge of the Petri plate. Parasitism was determined after 8 days of incubation, calculating the percentage of parasited eggs. The mycelial growth of P. lilacinus isolates was greatly dependent on the temperature. The fastest growth occurred at 22.5C. The isolates of P. lilacinus were able to infect M. paranaensis eggs in PDA medium, mostly at 25C.

  17. Anlise da variabilidade gentica de acessos de Psidium spp. (Myrtaceae) avaliados quanto reao a Meloidogyne enterolobii / Analysis of genetic variability of Psidium spp. (Myrtaceae) access evaluated for resistant to Meloidogyne enterolobii

    Eduardo Jos, Almeida; Ester, Wickert; Jaime Maia, Santos; Antonio Baldo Geraldo, Martins.

    2012-06-01

    Full Text Available Este trabalho teve por objetivo a caracterizao molecular de 13 acessos de Psidium spp. (Myrtaceae) identificados previamente quanto reao ao nematoide da goiabeira. A extrao do DNA das amostras foi executada conforme o protocolo de Shillito e Saul (1988). Os marcadores moleculares do tipo fAF [...] LP, foram obtidos utilizando-se do 'fAFLP Regular Plant Genomes Fingerprinting Kit' (Applied Biosystems do Brasil Ltda.) onde foram testadas 24 combinaes seletivas de primers, das quais 18 apresentaram amplificao que gerou 272 marcadores polimrficos. Para a anlise dos marcadores, foram utilizados os softwares GeneScan (ABI Prism verso 1.0) e Genotyper (ABI Prism verso 1.03), e os dados coletados foram transformados em matriz binria que foi analisada no software PAUP (Phylogenetic Analysis Using Parcimony - verso 3.01). Foram tambm calculados ndices de distncia gentica intra e interespecfica entre os materiais. Verificou-se que os marcadores AFLP foram eficientes na discriminao dos acessos entre si, bem como apontou similaridade gentica entre os acessos identificados como resistentes ao nematoide Meloidogyne enterolobii, caracterstica esta passvel de explorao no futuro. Abstract in english This study aimed to characterize molecular of 13 accessions of Psidium spp. (Myrtaceae) that was been identified for the reaction to rootknot guava nematode. The DNA extraction of the samples was carried according to the protocol of Shillito & Saul (1988). The molecular markers type fAFLP, were obta [...] ined from 'fAFLP Regular Plant Genomes Fingerprinting Kit' (Applied Biosystems from Brasil Ltda.) and were tested 24 selectives combinations of primers, of which 18 showed amplification that produced 272 polymorphic markers. To the analysis of the markers were employed the softwares GeneScan (ABI Prism verso 1.0) and Genotyper (ABI Prism version 1.03), and the data collected were transformed into a binary matrix that was analyzed in the software PAUP (Phylogenetic Analysis Using Parcimony - version 3.01). Were calculated genetic distance ndex intra and interespecific between the genotipes. It was found that the AFLP markers were efficient in the discrimination between accessions, as well as in showing genetic similarity among accessions identified as resistant to the nematode Meloidogyne enterolobii, which could be discussed in the future.

  18. The Role of Different Inoculum Levels of Meloidogyne javanica Juveniles on Nematode Reproduction and Host Response of Peanut Plant

    A.G. El-Sherif

    2009-01-01

    Full Text Available A pot experiment was conducted to determine the influence of three of inoculum levels (1000, 2000 and 3000 J2 pot-1 of Meloidogyne javanica on nematode reproduction and host response of peanut plant cv. Giza 4 under greenhouse conditions at at 30±5°C. In general, nematode reproduction and host damage were both affected by the initial inoculum levels. The greater reduction percentage of plant fresh (57.7%, shoot dry (38.82 and pods weights (52.59% and nodules numbers (73.33% were recorded at inoclum level 2000 J2/peanut plant, when rate of nematode build-up reached the maximum value of 1.64. Regression analysis of Pi vs. rate of nematode build-up on peanut plants gave value of R2 amounted to 0.3193. On the other hand, when the initial inoculum level added increased up to 3000 J2/peanut plant, the percentage reduction of whole plant fresh weight (47.07% and other growth parameters as well as nematode build-up (0.8 also obviously decreased.

  19. Root-Lesion Nematodes Suppress Cabbage Aphid Population Development by Reducing Aphid Daily Reproduction

    Hol, W. H. G.; Raaijmakers, Ciska E.; Mons, Ilse; Meyer, Katrin M.; van Dam, Nicole M.

    2016-01-01

    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 modeling approach to analyze 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 female–1 day–1) in comparison to both uninfested plants and plants with Meloidogyne spp. (3.50 offspring female–1 day–1). 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. PMID:26904074

  20. Reação de clones de umezeiro (Prunus mume sieb. et zucc. e cultivares de pessegueiro a Meloidogyne javanica (treub, 1885 Chitwood, 1949

    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.

  1. Avaliação de acessos de Psidium spp. quanto à resistência a Meloidogyne enterolobii Assessment of Psidium spp. accessions for resistance to Meloidogyne enterolobii

    Guilherme Bessa Miranda

    2012-01-01

    Full Text Available Quarenta e sete acessos de Psidium spp. foram avaliados em casa de vegetação quanto à resistência a M. enterolobii, visando ao desenvolvimento de porta-enxertos e cultivares resistentes. Cinco a sete mudas de cada acesso foram produzidas por propagação vegetativa ou a partir de sementes e, no estádio de quatro pares de folhas, foram submetidas à inoculação com 500 ovos desse nematoide. Cento e trinta e cinco dias após, extraiu-se metade do sistema radicular das plantas (cortado ao longo de seu eixo longitudinal para extração de ovos. As mudas foram replantadas com as raízes restantes e mantidas vivas em casa de vegetação. As contagens de ovos foram feitas em três alíquotas de 1 mL/planta, e multiplicadas por dois para obtenção da população final (Pf. As Pf's de todas as alíquotas foram submetidas a ANOVA, a qual indicou diferenças significativas (pForty-seven accessions of Psidium spp. were evaluated under greenhouse conditions for resistance to M. enterolobii, as part of an effort to develop resistant rootstocks and cultivars. For each accession, five to seven plants were produced from stem cuttings or from true seeds and, at the stage of four pairs of leaves, they were inoculated with 500 nematode eggs. One hundred and thirty-five days later, the plants were removed from the pots and half of root system was processed for extraction of eggs. The plants were replanted with the remaining roots. The egg counts, obtained from three 1 mL aliquots per plant, were multiplied by two to obtain the final nematode population (Pf. The Pf values of all aliquots were submitted to ANOVA, which revealed significant differences among accessions and among plants of the same accession. The plants were classified as resistant or susceptible based on the reproduction factor (RF = Pf/500. All plants of cattley guava (P. cattleyanum (accessions 115 and 116 were resistant (RF <1 to M. enterolobii, while other Psidium spp. presented some plants with RF below or just above 1. These plants will be propagated and reassessed for resistance to M. enterolobii.

  2. Evaluacin de la actividad biocontroladora de arthrobotrys sp. y paecilomyces sp. sobre meloidogyne javanica in vitro y bajo condiciones de invernadero en crisantemo (drendranthema grandiflora andernson)

    Dvila Lida; Clmaco Ho Juan

    2010-01-01

    Para evaluar la accin biocontroladora de Arthrobotrys sp. y Paecilomyces sp. sobre huevos y larvas de Meloidogyne javanica en crisantemo, se realizaron pruebas in vitro y en invernadero. Se tomaron 500 larvas y 500 huevos del nematodo ...

  3. Variabilidade genética de acessos de araçazeiro e goiabeira suscetíveis e resistentes a Meloidogyne enterolobii

    Aline das Graças Souza; Luciane Vilela Resende; Isabela Pereira de Lima; Rosimar Musser dos Santos; Nilton Nagib Jorge Chalfun

    2014-01-01

    A goiabeira representa uma importante atividade frutícola no Brasil, com mercado cada vez maior. Porém, desde 1989 vêm sendo relatados severos danos à cultura, causados pelo nematóide Meloidogyne enterolobii. Uma das alternativas para solucionar esse problema é a utilização de porta-enxertos com resistência a este patógeno. Este trabalho teve por objetivo a caracterização molecular, com marcadores RAPD, de acessos de Psidium testados quanto à resistência a M. enterolobii e quanto à compatibil...

  4. Characterization and efficacy of bacterial strains for biological control of soil-borne diseases caused by Phytophthora cactorum and Meloidogyne javanica on Rosaceous plants

    Agustí Alcals, Lourdes

    2008-01-01

    S'avaluaren 58 soques de Pseudomonas fluorescens i Pantoea agglomerans per la seva eficàcia en el biocontrol de la malaltia causada per l'oomicet Phytophthora cactorum en maduixera i pel nematode formador de gal·les Meloidogyne javanica en el portaempelt GF-677.Es desenvolupà un mètode ex vivo d'inoculació de fulla amb l'objectiu de seleccionar soques bacterianes com a agents de control biològic de P. cactorum en maduixera. Tres soques de P. fluorescens es seleccionaren com a soques eficaces ...

  5. Effect of Temperature, Soil pH, Agitation Intervals and Soil Types on the Spore Attachment of Pasteuria penetrans to Root Knot Nematodes, Meloidogyne javanica

    Nazir Javed

    2002-01-01

    Full Text Available Studies were conducted to see the effect of various factors viz; temperature, soil pH, agitation intervals and soil types on the spore attachment of Pasteuria penetrans to Meloidogyne javanica. All the experiments were conducted in growth room where temperature was maintained at 28oC. Results revealed that the spore attachment increased with the increase in temperature, soil pH (from neutral to alkaline and agitation intervals. It was observed that there was no effect of soil types on the spore attachment.

  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

    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 intensity of root-knotting of carrot. No significant differences were detected in the biological yield of carrot plants, but commercial average production obtained from plots.treated with R. graveolens and T. officinale were the highest (3070 g.m·2 and 2270 g.m·2 and significantly different from the control plots (1090 g.m·2. Final average population densities of infective secondstage
    juveniles [J2] of M. hapla were significantly lower in the plots treated with R. communis, T. officinale, B. campes tris and T. erecta (65-130 Jj100 g of soil than in the control plots (435 J2/100 g of soil. Significant differences were detected between rootknotting intensity of control plots (5.0 knots per root tip and the averages of other treaments (1.9-2.6 knots per root tip.

  7. Incorporao ao solo de substrato contendo miclio e condios de Pochonia chlamydosporia para o manejo de Meloidogyne javanica / Soil amendment with substrate containing mycelium and conidia of Pochonia chlamydosporia for the management of Meloidogyne javanica

    Rosangela, Dallemole-Giaretta; Leandro Grassi de, Freitas; Deborah Magalhes, Xavier; Ronaldo Joo Falco, Zooca; Silamar, Ferraz; Everaldo Antnio, Lopes.

    2014-04-01

    Full Text Available Os clamidsporos so os principais propgulos utilizados como fonte de inculo de Pochonia chlamydosporia em experimentos envolvendo o biocontrole do nematoide das galhas. O presente trabalho teve por objetivo avaliar o controle de Meloidogyne javanica em tomateiro por meio da aplicao ao solo de g [...] ros de arroz colonizados pelo fungo contendo apenas miclio e condio, sem a presena de clamidsporos. O isolado de P. chlamydosporia Pc-10 foi cultivado por 15 dias a 26C em arroz previamente esterilizado em forno microondas. Dois experimentos foram conduzidos simultaneamente em casa de vegetao. No experimento 1, vasos de 2L de capacidade foram preenchidos com mistura solo:areia (1:1, v:v), contendo 3g kg-1 de solo de gros de arroz colonizados pelo antagonista. No experimento 2, o fungo foi adicionado ao solo de vasos de 0,5L nas doses de 1, 5, 10, 15, 20, 25 ou 30g kg-1 de solo. Em seguida, o substrato de cada vaso foi infestado com 4.000 ovos de M. javanica e, aps 15 dias, uma plntula de tomate foi transplantada. No experimento 1, a aplicao do fungo ao solo reduziu o nmero de galhas e de ovos do nematoide em 40% e 72,83%, respectivamente. No experimento 2, houve reduo do nmero de ovos a partir de doses de 5g kg 1 de solo e no nmero de galhas, principalmente, nas doses de 25 e 30g kg-1 de solo. Conclui-se que P. chlamydosporia Pc-10 controlou M. javanica em tomateiro, mesmo quando aplicado ao solo na forma de gros de arroz colonizados e sem a presena de clamidsporos. Abstract in english Chlamydospores are the main propagules used as source of inoculum of Pochonia chlamydosporia in biocontrol experiments of root-knot nematodes. The objective of this study was to evaluate the control of Meloidogyne javanica on tomato plants by the soil application of rice grains colonized by Pochonia [...] chlamydosporia containing just mycelium and conidia, without chlamydospores. The fungus (isolate Pc-10) was grown for 15 days at 26C on grains of rice, previously sterilized in microwave oven. Two experiments were simultaneously carried out under greenhouse conditions. In the experiment 1, 2-L pots were filled with a soil:sand mixture (1:1, v:v) containing 3g kg-1 of soil of rice grains colonized by the antagonist. In the experiment 2, the fungus was added into the soil of 0.5L pots at the doses of 5, 10, 15, 20, 25 or 30g kg-1 of soil. The soil of each pot was infested with 4,000 eggs of M. javanica and one tomato seedling was transplanted in each pot after fifteen days. In the experiment 1, the application of the fungus into the soil reduced the number of galls and eggs of the nematode by 40% and 72.83%, respectively. In the experiment 2, it was observed the reduction of the number of eggs from the dose of 5 g kg-1 of soil and of the number of galls, particularly at the doses of 25 and 30g kg-1 of soil. As a conclusion, P. chlamydosporia controlled M. javanica on tomato plants even when applied into the soil as colonized-rice grains and without chlamydospores.

  8. Control of Meloidogyne enterolobii in guava seedlings with mycorrhizal fungi isolated from Bahia Savanna = Controle de Meloidogyne enterolobii em mudas de goiabeira com fungos micorrízicos isolados do Cerrado baiano.

    Aracy Camilla Tardin Pinheiro

    2014-12-01

    Full Text Available The nematode Meloidogyne enterolobii causes severe damage to guava tree, being a limiting factor to production. Arbuscular mycorrhizal fungi (AMF can impair the development of some species of plant parasitic nematodes by reducing oviposition and the number of galls in the roots of infected plants. The present research aimed to evaluate the potential of AMF, isolated from soils of native savanna, in reducing the infectivity of M. enterolobii in guava tree seedlings. For this purpose, an experiment was conducted in a greenhouse in randomized block design with eight replications, in which we evaluated the percentage of mycorrhizal colonization, the number of galls and eggs of the mentioned nematode per gram of root, in the presence of eight different fungal isolates, and the control without the presence of the fungus, in the guava tree. All AMF isolates from the savanna were effective on root colonization, reduced the number of nematode’s galls and affected their reproduction; however, the degree of root colonization by mycorrhizal fungi, alone, is not indicative of infectivity control of this pathogen, since some isolates showing increased colonization were less effective in reducing it, so that the evaluated AMF isolates differed regarding the efficiency in reducing the reproduction of M. enterolobii in guava tree seedlings. = O nematoide Meloidogyne enterolobii causa severos danos à goiabeira, sendo um fator limitante à produção. Os fungos micorrízicos arbusculares (FMA podem prejudicar o desenvolvimento de algumas espécies de nematoides fitoparasitos, reduzindo a ovoposição e o número de galhas no sistema radicular de plantas infectadas. Com o presente trabalho, objetivouse avaliar o potencial de FMA, isolados de solos de cerrado nativo, em reduzir a infectividade de M. enterolobii em mudas de goiabeira. Para tanto, foi conduzido um experimento em casa de vegetação, em blocos casualizados com oito repetições, no qual se avaliou a porcentagem de colonização micorrízica, o número de galhas e de ovos do nematoide citado por grama de raiz, na presença de oito diferentes isolados fúngicos, e a testemunha, sem presença de fungo, em goiabeira. Todos os isolados de FMA oriundos do bioma cerrado foram eficientes na colonização das raízes, reduziram o número de galhas do nematoide e afetaram a reprodução; no entanto, o grau de colonização radicular pelos fungos micorrízicos, isoladamente, não é um indicativo de controle da infectividade desse patógeno, já que alguns isolados que apresentaram maior colonização foram menos eficazes na sua redução, de forma que os isolados de FMA avaliados diferiram quanto à eficiência em reduzir a reprodução de M. enterolobii em mudas de goiabeira. Key words - . . .

  9. SELEÇÃO DE GENÓTIPOS DE ABACAXI PARA RESISTÊNCIA A Meloidogyne javanica E Pratylenchus brachyurus RESISTANCE OF PINEAPPLE GENOTYPES TO Meloidogyne javanica AND Pratylenchus brachyurus

    Carlos Humberto Calfa

    2007-09-01

    Full Text Available

    Dez genótipos de abacaxi foram avaliados para resistência às espécies de nematóides, Meloidogyne javanica e Pratylenchus brachyurus, em dois experimentos conduzidos em casa de vegetação, seguindo o delineamento inteiramente casualizado com seis repetições, empregando o cv. Smooth Cayenne como padrão de suscetibilidade. Cada parcela foi constituída de uma planta/vaso, contendo solo esterilizado com brometo de metila. Após dois meses do plantio das mudas, as plantas foram inoculadas com 1.000 juvenis (J2 de M. javanica no primeiro experimento e 1.000 indivíduos de P. brachyurus no segundo experimento. Após 90 dias da inoculação foram avaliados os seguintes parâmetros: peso do sistema radicular, número de ovos e de nematóides por planta e fatores de reprodução. A seleção para resistência foi baseada na percentagem de redução do fator de reprodução. Em relação a M. javanica, os genótipos FRF-632 e H-3607 foram pouco resistentes (PR e os de LBB-1385, Primavera, FRF-609 e LBB-1396 comportaram-se como moderadamente resistentes (MR. Para P. brachyurus foram selecionados como pouco resistentes (PR os genótipos de H-3607, LBB-396, Perolera, FRF-609 e Primavera.

    PALAVRAS-CHAVES: Ananas comosus; resistência; nematóide das galhas; nematóide das lesões radiculares.

    The resistance of ten genotypes of pineapple to two nematodes species, Meloidogyne javanica and Pratylenchus brachyurus, was evaluated in two experiments at greenhouse. Each one of them was completely randomized with six replications. The cultivar Smooth Cayenne was used as a susceptible control. Each plot was represented by one plant/pot. Each pot held 4 l of soil previouly sterilized with metil bromide. Pineapple seedlings were inoculated, two months after planting, with 1,000 juveniles (J2 of M. javanica at the first experiment and 1,000 individuals of P. brachyurus at the second experiment. Taproot weight, eggs masses, nematodes per plant and reproduction rate were recorded 90 days after inoculation. The resistance selection was based on the percentage of the reproduction rate. The genotypes FRF- 632 and H- 3607 had minor resistance to M. javanica (PR and LBB- 1385, Primavera, FRF- 609 and LBB- 1396 presented moderated resistance (MR. The genotypes H- 3607, LBB-1396, Perolera, FRF- 609 and Primavera had minor resistance to P. brachyurus (PR.

    KEY-WORDS: Ananas comosus; resistance; root knot nematode; root lesion nematode.

  10. Selection of coffee progenies for resistance to nematode Meloidogyne paranaensis in infested area

    Sonia Maria Lima Salgado

    2014-07-01

    Full Text Available The purpose of this study was to select Coffea arabica progenies for resistance to M. paranaensis in an infested coffee growing area using Hendersons mixed model methodology. Forty-one genotypes were selected at the Coffee Active Germplasm Bank of Minas Gerais, and evaluated in regard to stem diameter, number of plagiotropic branches, reaction to the nematode, and yield per plant. There was genetic variability among the genotypes studied for all the traits evaluated, and among the populations studied for yield and reaction to the nematode, indicating possibilities for obtaining genetic gains through selection in this population. There was high rate of genotypic association between all the traits studied. Coffee plants of Timor Hybrid UFV408-01 population, and F3 progenies derived from crossing Catua Vermelho and Amphillo MR 2161 were the most promising in the area infested by M. paranaensis.

  11. Efeito antagônico de feijão-de-porco sobre Meloidogyne enterolobii em tomateiro

    Servio Robinson Cabezas Morillo

    2015-12-01

    Full Text Available RESUMOO presente trabalho teve como objetivo avaliar o efeito antagônico do feijão-de-porco (Canavalia ensiformis sobre Meloidogyne enterolobii em tomateiro (Solanum lycopersicum. Foram estudados os efeitos do extrato aquoso de sementes de feijão-de-porco, nas concentrações 0, 1, 2, 4 e 8 g de sementes /100 mL de água sobre a eclosão e a mortalidade de juvenis (J2 in vitro. Em condições de casa-de-vegetação, avaliou-se o efeito da rega do solo, a pulverização das plantas com extrato aquoso e a incorporação de farinha de sementes ao solo, sobre os índices de galhas (IG e de massas de ovos (MO em raízes de tomateiro. Os resultados mostraram que todas as concentrações do extrato foram eficientes tanto na redução de eclosão como na mortalidade de juvenis de M. enterolobii, quando comparados à testemunha, também encontrou-se correlação positiva entre as concentrações. Houve redução no número de galhas e de massas de ovos tanto na rega do solo como na pulverização do extrato, sendo o efeito proporcional à concentração do extrato. Com a incorporação de farinha de sementes ao solo, houve efeito fitotóxico em todos os tratamentos, não se mostrando um método adequado.

  12. Reação de genótipos e híbridos de tomateiro à Meloidogyne enterolobii

    Juliana Magrinelli Osório Rosa

    2014-07-01

    Full Text Available A meloidoginose tem sido considerada uma das mais importantes doenças da cultura do tomate. O uso de tomateiros resistentes ao nematoide das galhas é medida bastante utilizada no controle de diferentes espécies, entretanto, a reação de tomateiros à Meloidogyne enterolobii ainda é pouco conhecida. Portanto, objetivou-se a determinação da reprodução de M. enterolobii em dez híbridos de tomate (Absoluto, Cascade, Cordillera, Donatto, Ellen, Fascínio, Laura, Marguerita, Nícolas e Sanni e dois genótipos experimentais (05 tom0041 e 08 tom00345. Os ensaios foram conduzidos em casa de vegetação e em BOD (25°C, com cinco e três repetições por tratamento, respectivamente. A infestação do substrato foi realizada com 5.000 ovos e eventuais juvenis de segundo estádio de M. enterolobii/vaso, dois dias após o transplante das plântulas. A avaliação do índice de galhas, índice de massa de ovos, população final e fator de reprodução foi realizada 60 dias após a inoculação. Em ambos os ensaios, verificou-se a suscetibilidade de todos os genótipos e híbridos avaliados.

  13. An Extension of the Mellor-Yamada Model to the Terra Incognita Zone for Dry Convective Mixed Layers in the Free Convection Regime

    Ito, Junshi; Niino, Hiroshi; Nakanishi, Mikio; Moeng, Chin-Hoh

    2015-10-01

    The terra incognita (TI) or grey zone arises in conventional planetary boundary-layer parametrizations when the grid resolution of a numerical model is comparable to the size of the energy-containing turbulent eddies 1 km or less. Here, we investigate a simple, plausible extension of the Mellor-Yamada (MY) level-3 scheme for TI-scale grid size using a large-eddy simulation (LES) as a benchmark. Horizontal filtering of the benchmark simulation data for the dry convective mixed layer in the free convection regime yields subfilter-scale components whose statistics are then retrieved for various filter sizes. This leads to a modified MY level-3 scheme for TI-scale grid sizes. The proposed TI scheme incorporates: (1) modification of various length scales in the conventional MY scheme by an empirical function that depends on the horizontal grid size normalized by the convective boundary-layer height; (2) a new length scale for horizontal turbulent fluxes; and (3) a linear relationship between the local dissipation length and subfilter-scale turbulent kinetic energy. A posteriori tests of the proposed TI scheme show a much improved performance compared with the conventional MY level-3 scheme. The ratio of the grid-scale to the subgrid-scale turbulent intensity is comparable to that obtained from the filtered LES solutions. Sensitivity tests show that the modification of the dissipation length scales has the largest impact, while the new length scale for horizontal fluxes also proves important. A simulation that includes all of the above modifications results in the optimum performance.

  14. Influence of Azolla pinnata in Combination with Mustard Oil Cake on the Galling of Meloidogyne javanica and the Growth of Eggplant

    Tahmid

    2002-01-01

    Full Text Available Effect of Azolla (Azolla pinnata in combination with mustard oil cake (MOC was studied on the galling in roots and growth of eggplants (Solanum melongena inoculated with Meloidogyne javanica. Fresh weight and length of both shoot and root were vigorous when dry Azolla (5g or fresh Azolla extract (10ml in mixing with the half standard dose (1.25g of MOC was applied. Similarly, the galling incidence was lower in the same treatment that was identified for the vigorous growth of the plant. A. pinnata was found as a very effective agent for the normal growth of root and shoot with half-standard dose of MOC. Both of these agents in together created resistance to the plants and its toxic materials might suppress the nematode activity, which ultimately confirm the lower presence of galling by M. javanica.

  15. The potential of increased nitrogen supply to mitigate growth and yield reductions of upland rice cultivar UPL Ri-5 caused by Meloidogyne graminicola

    Prot, Jean-Claude; Villanueva, L.M.; Gergon, E.B.

    1994-01-01

    Les effets de #Meloidogyne graminicola$ et d'applications d'azote sur la croissance et le rendement du riz pluvial cv. UPL Ri 5 ont été étudiés au cours de deux expériences en serre. La hauteur des plants, le poids des parties aériennes et des racines, la surface foliaire, la profondeur d'enracinement et le nombre de panicules et de grains sont diminués par le nématode. Le rendement est réduit de 30-70 % lorsque le nombre de juvéniles de second stade présents à la transplantation autour des j...

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

    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 32P 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 CO2 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 14C in various photosynthetic products were recognized, and main 14C 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)

  17. The Effect of Animal Manures on Susceptibility of Cowpea VAR. Moussa Local to Infection by Root-knot Nematode; Meloidogyne javanica Treub

    A.O. Ogaraku

    2007-01-01

    Full Text Available The effect of three different types of animal manures namely; poultry, goat and cow dung on the susceptibility of cowpea (Vigna unguiculata (L. Walp Var moussa local to root-knot nematode infection caused by Meloidogyne javanica was tested in a replicated pot experiment. Manured plants were inoculated with 2000 eggs of M. javanica while uninoculated manured plants served as control for each manure type and unmanured but inoculated plants as general control. The result showed that unmanured and inoculated plants were susceptible to M. javanica to varying degrees. Plants applied with poultry manure were more resistant to root-knot nematode infection followed by those applied with cow dung and goat dropping in that order. The most susceptible plants were those inoculated but not applied with manure. Gall index and resistance rating showed that plants fertilized with poultry manure, cow dung and goat droppings were resistant, moderately resistant and susceptible, respectively.

  18. Toxicity of 2,4-diacetylphloroglucinol (DAPG) to plant-parasitic and bacterial-feeding nematodes.

    Meyer, Susan L F; Halbrendt, John M; Carta, Lynn K; Skantar, Andrea M; Liu, Ting; Abdelnabby, Hazem M E; Vinyard, Bryan T

    2009-12-01

    The antibiotic 2,4-diacetylphloroglucinol (DAPG) is produced by some isolates of the beneficial bacterium Pseudomonas fluorescens. DAPG is toxic to many organisms, and crop yield increases have been reported after application of DAPG-producing P. fluorescens. This study was conducted to determine whether DAPG is toxic to selected nematodes. The plant-parasitic nematodes Heterodera glycines, Meloidogyne incognita, Pratylenchus scribneri and Xiphinema americanum, and the bacterial-feeding nematodes Caenorhabditis elegans, Pristionchus pacificus, and Rhabditis rainai, were immersed in concentrations ranging from 0 to 100 ?g/ml DAPG. Egg hatch and viability of juveniles and adults were determined. DAPG was toxic to X. americanum adults, with an LD?? of 8.3 ?g/ml DAPG. DAPG decreased M. incognita egg hatch, but stimulated C. elegans hatch during the first hours of incubation. Viability of M. incognita J2 and of C. elegans J1 and adults was not affected. There were no observed effects on the other nematodes. The study indicated that DAPG is not toxic to all nematodes, and did not affect the tested species of beneficial bacterial-feeding nematodes. Augmentation of DAPG-producing P. fluorescens populations for nematode biocontrol could be targeted to specific nematode species known to be affected by this compound and by other antibiotics produced by the bacteria, or these bacteria could be used for other possible effects, such as induced plant resistance. PMID:22736826

  19. The effect of temperature on hatch and activity of second-stage juveniles of the root-knot nematode, Meloidogyne minor, an emerging pest in north-west Europe

    Morris, Karen S.; Horgan, Finbarr G.; Downes, Martin J.; Griffin, Christine T.

    2011-01-01

    Meloidogyne minor is a serious threat to turfgrass in north-west Europe, and has a broad host range that includes other economically important plants. The species was described only recently and little is known about its biology. This study examines the effect of temperature on hatch and motility of second-stage juveniles (J2), and records hatching from egg masses collected from golf greens in different seasons. Eggs were present throughout the year and a high percentage hatch (46-88...

  20. Long-Term In Vitro System for Maintenance and Amplification of Root-Knot Nematodes in Cucumis sativus Roots

    Daz-Manzano, Fernando E.; Olmo, Roco; Cabrera, Javier; Barcala, Marta; Escobar, Carolina; Fenoll, Carmen

    2016-01-01

    Root-knot nematodes (RKN) are polyphagous plant-parasitic roundworms that produce large crop losses, representing a relevant agricultural pest worldwide. After infection, they induce swollen root structures called galls containing giant cells (GCs) indispensable for nematode development. Among efficient control methods are biotechnology-based strategies that require a deep knowledge of underlying molecular processes during the plant-nematode interaction. Methods of achieving this knowledge include the application of molecular biology techniques such as transcriptomics (as massive sequencing or microarray hybridization), proteomics or metabolomics. These require aseptic experimental conditions, as undetected contamination with other microorganisms could compromise the interpretation of the results. Herein, we present a simple, efficient and long-term method for nematode amplification on cucumber roots grown in vitro. Amplification of juveniles (J2) from the starting inoculum is around 40-fold. The method was validated for three Meloidogyne species (Meloidogyne javanica, M. incognita, and M. arenaria), producing viable and robust freshly hatched J2s. These J2s can be used for further in vitro infection of different plant species such as Arabidopsis, tobacco and tomato, as well as to maintain and amplify the population. The method allowed maintenance of around 90 Meloidogyne sp. generations (one every 2 months) from a single initial female over 15 years. PMID:26941745

  1. A farmer friendly and economic IPM strategy to combat root-knot nematodes infesting lentil

    Rose Rizvi; Rizwan Ali Ansari; Gulshan Zehra; Irshad Mahmood

    2015-01-01

    An experiment was conducted to assess the effect of Rhizobium sp., waste tea leaves, eggshell powder, and composted cow dung manure on the root-knot nematode, Meloidogyne incognita, on lentil in Botany department AMU, Aligarh, India. When used alone, composted cow dung was better in reducing galling and nematode multiplication and improving lentil growth followed by eggshell powder, Rhizobium sp., and waste tea leaves. Significant result in the integrated management of M. incognita was obtain...

  2. 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

    Wânia dos Santos Neves

    2009-12-01

    Full Text Available Neves, W.S; Freitas, L.G.; Coutinho, M.M.; Giaretta-Dallemole, R.; Fabry, C.F.S.; Dhingra, O.D. & Ferraz, S. Atividade nematicida de extratos botânicos de pimenta malagueta (Capsicum frutescens, mostarda (Brassica campestris e alho (Allium sativum sobre o nematóide das galhas, Meloidogyne javanica, em casa de vegetação. Summa Phytopathologica, v.35, n.4, p.255-261, 2009 O experimento teve como objetivo avaliar a atividade nematicida de extratos botânicos dos frutos de pimenta malagueta (Capsicum frutescens, plantas de mostarda (Brassica campestris, de bulbos de alho (Allium sativum e óleo de mostarda sobre o nematóide das galhas, Meloidogyne javanica, em tomateiro em casa de vegetação e posteriormente comparar os extratos que apresentassem maior redução de número de galhas e de ovos com dois produtos à base de capsaicina, capsainóides e alil isotiocianato. Uma mistura peneirada de solo e areia na proporção 1:1 (v:v foi colocada em vasos de plástico e infestada com 4000 ovos de M. javanica. Quatro dias após 20 mL de cada extrato, na concentração de 1000 ppm, foram espalhados sobre o solo. Apenas água foi derramada sobre o solo infestado no tratamento testemunha. Mudas de tomate com 20 dias de idade foram transplantadas quatro dias após a colocação dos extratos ao solo. Após quarenta e cinco dias avaliou-se o número de ovos e o número de galhas do sistema radicular de cada planta. Os extratos clorofórmico e cetônico de pimenta malagueta e o óleo de mostarda apresentaram melhor controle do nematóide, diferindo estatisticamente da testemunha quanto ao número de galhas. Porém, somente o óleo de mostarda reduziu significativamente o número de ovos quando comparado com a testemunha. Os extratos cetônico e clorofórmico de pimenta e o óleo de mostarda reduziram em 34,5%, 40,4% e 99,9% o número de galhas, respectivamente e o óleo de mostarda reduziu em 99,9% o número de ovos. No experimento seguinte foram avaliados 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 number of galls, but only the mustard oil differed from the control in the number of eggs per plant. The chloroformic and cetonic extracts of chili pepper and the mustard oil reduced in 34,5%, 40,4% and 99,9% the number of galls, respectively, and the mustard oil reduced the number of eggs in 99,9%. In the following experiment, the chloroformic extract of chili pepper, the mustard oil, a commercial product (Champon® and a product in development at the UFV called DS, both containing capsaicin, capsainoids and allyl isothiocyanate, were compared at different concentrations. The Champon®, the DS and the mustard oil reduced the egg and gall numbers in comparison with the control treatment in all the tested concentrations. The pepper extract show the best result at 400 ppm, reducing the number of galls and eggs per root system in relation to the control treatment, however, these numbers were much higher than the observed in the Champon® and the DS treatments.

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

    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...

  4. Effects of the Mi-1 and the N root-knot nematode-resistance gene on infection and reproduction of Meloidogyne enterolobii on tomato and pepper cultivars.

    Kiewnick, Sebastian; Dessimoz, Mireille; Franck, Lucie

    2009-06-01

    Meloidogyne enterolobii is widely considered to be an aggressive root-knot nematode species that is able to reproduce on root-knot nematode-resistant tomato and pepper cultivars. In greenhouse experiments, M. enterolobii isolates 1 and 2 from Switzerland were able to reproduce on tomato cultivars carrying the Mi-1 resistance gene as well as an N-carrying pepper cultivar. Reproduction factors (Rf) ranged between 12 and 109 depending on the plant cultivar, with M. enterolobii isolate 2 being more virulent when compared to isolate 1. In contrast, M. arenaria completely failed to reproduce on these resistant tomato and pepper cultivars. Although some variability in virulence and effectiveness of root-knot nematode-resistance genes was detected, none of the plant cultivars showed Rf values less than 1 or less than 10% of the reproduction observed on the susceptible cv. 'Moneymaker' (Rf = 23-44) used to characterize resistance. The ability of M. enterolobii to overcome the resistance of tomato and pepper carrying the Mi-1 and the N gene makes it difficult to manage this root-knot nematode species, particularly in organic farming systems where chemical control is not an option. PMID:22661786

  5. A species-specific satellite DNA family in the genome of the coffee root-knot nematode Meloidogyne exigua: application to molecular diagnostics of the parasite.

    Randig, Onivaldo; Bongiovanni, Michel; Carneiro, Regina M D G; Sarah, Jean-Louis; Castagnone-Sereno, Philippe

    2002-11-01

    SUMMARY A new BglII satellite DNA has been isolated, cloned and sequenced from the coffee root-knot nematode, Meloidogyne exigua (Nematoda: Tylenchida). It is represented as tandemly repeated sequences with a monomeric unit of 277 bp. The monomers are present at approximately 17 900 copies per haploid genome, and represent about 9.7% of the total genomic DNA. Twenty randomly chosen monomers have been sequenced. The deduced unambiguous consensus sequence is 277 bp long, and displays an A + T content of 54.2%. The monomers are very homogenous in sequence, showing on average 2.4% divergence from their consensus. Therefore, it is hypothesized that this repeated family may have recently appeared in the genome of the nematode, through some extensive amplification burst. Using a cloned monomer as a probe, dot-blot experiments demonstrated the species-specific distribution of the BglII satellite DNA. Moreover, squash-blot assays allowed us to detect single M. exigua individuals, at any developmental stage, and even within root tissues, without the need for preliminary DNA purification. From these results, it is concluded that the procedure described, using the satellite DNA as a sensitive species-specific probe, should constitute an improved and accurate diagnosis method for the detection and identification of the nematode, which would contribute to the implementation of targeted pest management strategies in all coffee growing countries of South and Central America. PMID:20569350

  6. Population dynamics

    Cooch, E. G.; Dhondt, A A

    2004-01-01

    Increases or decreases in the size of populations over space and time are, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change over time in the abundance of some population is the simple difference between the number of additions (individuals entering the population) minus the number of subtractions (individuals leaving the population). Of course, the precise nature of the patter...

  7. Influence of Azolla pinnata in Combination with Mustard Oil Cake on the Galling of Meloidogyne javanica and the Growth of Eggplant

    Tahmid; Ansari, H; Malek, M. A; M. U. Ahmed; Sota Tanaka; Tetsushi Yoshida

    2002-01-01

    Effect of Azolla (Azolla pinnata) in combination with mustard oil cake (MOC) was studied on the galling in roots and growth of eggplants (Solanum melongena) inoculated with Meloidogyne javanica. Fresh weight and length of both shoot and root were vigorous when dry Azolla (5g) or fresh Azolla extract (10ml) in mixing with the half standard dose (1.25g) of MOC was applied. Similarly, the galling incidence was lower in the same treatment that was identified for the vigorous growth of the plant. ...

  8. 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

    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 of these nematodes attacking okra have already been reported in Brazil, and some of them can cause plant death. The correct identification of Meloidogyne species and, or races infecting okra roots is mandatory for choosing appropriate control measures. To determine the occurrence and distribution of Meloidogyne spp. and other nematodes in the area of the East of MG, 70 soil and root samples coming from 14 municipalities were appraised for morphological and isoenzymatic characteristics. Among the populations of Meloidogyne spp., M. incognita (Esterase phenotypes I1 and I2 prevailed and were followed by M. javanica (phenotypes J2 and J3 and M. arenaria (phenotypes A2. The species M. mayaguensis was confirmed by the phenotypes: esterase (M2, malate dehydrogenase (N3, superoxide dismutase (N2 and glutamate oxaloacetate transaminase (N3. This is the first report of the M. mayaguensis occurrence in MG. Other nematodes associated with the okra plants were Aphelenchus sp., Criconemella sp., Helicotylenchus spp., Pratylenchus brachyurus and P. coffeae, Rotylenchulus reniformis, Rotylenchus sp., Tylenchus sp. and Tylenchorhynchus sp.

  9. Efeito de extratos proteicos de amendoim sobre o desenvolvimento, a capacidade infectiva e atividade de enzimas proteolíticas de Meloidogyne enterolobii

    Juliana Martins Ribeiro

    2014-06-01

    Full Text Available No Brasil, Meloidogyne enterolobii vem causando perdas significativas na produção de goiabeiras e, no submédio do Vale do São Francisco, por exemplo, o impacto negativo decorrente da infecção e morte de goiabeiras tem refletido diretamente na qualidade de vida dos agricultores. Até o momento, não existem métodos de controle efetivos: os nematicidas avaliados experimentalmente não têm sido eficientes e não há produtos registrados no Ministério da Agricultura, Pecuária e Abastecimento para aplicação em goiabeiras. Assim, há necessidade de realizar pesquisa básica nesta área. A prospecção de proteínas relacionadas com a resistência em espécies resistentes pode ser uma alternativa para o desenvolvimento de medidas para seu controle. Para isso, foram realizados ensaios biológicos de toxicidade para a análise do efeito de extratos proteicos de amendoim sobre o desenvolvimento, a capacidade infectiva e atividade de enzimas proteolíticas de M. enterolobii visando à identificação de proteínas com potencial para controle desse nematoide. Os resultados obtidos indicaram que o extrato proteico total de amostras de raízes de plantas de amendoim inoculadas não tem efeito sobre as três características supracitadas. Sendo assim, são necessários estudos dessa natureza com outras espécies resistentes ao patógeno visando à identificação de proteínas que apresentem potencial para o seu controle.

  10. Imaginary populations

    Martínez–Abraín, A.

    2010-01-01

    A few years ago, Camus & Lima (2002) wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002), that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologis...

  11. Impact of New Natural Biostimulants on Increasing Synthesis in Plant Cells of Small Regulatory si/miRNA With High Anti-Nematodic Activity

    Victoria Anatolyivna Tsygankova; Galyna Alexandrovna Iutynska; Anatoliy Pavlovych Galkin; Yaroslav Borisovych Blume

    2013-01-01

    Plant endoparasitic cyst nematode Heterodera schachtii Schmidt, gallic nematode Meloidogyne incognita and stem nematode Ditylenchus destructor damage various agricultural crops. The application of ecologically safe natural biostimulants with bioprotective properties is a newer approach for increasing plant resistance to parasitic nematodes. The molecular-genetic analysis of biostimulants action on plant genome is necessary for creation of new effective bioregulators for plant protection again...

  12. Doenças da vinagreira no Estado do Maranhão

    Gilson Soares da Silva

    2014-12-01

    Full Text Available Neste trabalho, são descritas as principais doenças da vinagreira (Hibiscus sabdariffa que ocorrem no Estado do Maranhão. Os patógenos identificados foram Cercospora malayensis, Corynespora cassiicola, Lasiodiplodia theobromae, Meloidogyne incognita, Phytophthora nicotianae e Sclerotium rolfsii.

  13. Clove oil and fungus compounds: Can nematode suppression be achieved without phytotoxicity?

    Natural products from a plant (Syzygium aromaticum) and a fungus (Aspergillus sp.) were examined for the presence of compounds with potential for application as novel nematicides. The plant-derived material, clove oil, was tested in the greenhouse against the nematode Meloidogyne incognita on cucum...

  14. Phytotoxicity of Clove Oil to Vegetable Crop Seedlings and Nematotoxicity to Root-knot Nematodes

    Clove oil derived from the plant Syzygium aromaticum is active against various soilborne plant pathogens, and therefore has potential for use as a biobased pesticide. A clove oil formulation previously found to be toxic to the root-knot nematode Meloidogyne incognita in laboratory assays was invest...

  15. ACTIVITY OF FUNGAL CULTURE FILTRATES AGAINST SOYBEAN CYST NEMATODE AND ROOT-KNOT NEMATODE EGG HATCH AND JUVENILE MOTILITY

    Fungi were isolated from soybean cyst nematode (Heterodera glycines) eggs collected in China, and 253 isolates were assayed for production of compounds active against H. glycines and root-knot nematode (Meloidogyne incognita). Fungal isolates were grown for 3 and 7 days in potato dextrose broth (PD...

  16. Screening edible ginger and turmeric cultivars for resistance to root-knot nematodes

    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 ...

  17. Effect of Soils from Six Management Systems on Root-knot Nematodes and Plant Growth in Greenhouse Assays

    Kokalis-Burelle, N.; Chellemi, D. O.; Pris, X.

    2005-01-01

    The effects of soil management systems on root-knot nematode (Meloidogyne incognita) eggs and gall incidence on tomato (Lycopersicon esculentum) and cucumber (Cucumis sativus) following tomato were evaluated. Soil was collected from a replicated field experiment in which six management systems were being assessed for vegetable production. Soil management systems were conventional production, organic production, bahiagrass (Paspalum notatum) pasture, bahiagrass: Stylosanthes (Stylosanthes guia...

  18. Population Blocks.

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining

  19. Population Blocks.

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  20. Population crises and population cycles.

    Russell, C; Russell, W M

    2000-01-01

    To prevent a population irretrievably depleting its resources, mammals have evolved a behavioural and physiological response to population crisis. When a mammalian population becomes dangerously dense, there is a reversal of behaviour. Co-operation and parental behaviour are replaced by competition, dominance and aggressive violence, leading to high mortality, especially of females and young, and a reduced population. The stress of overpopulation and the resulting violence impairs both the immune and the reproductive systems. Hence epidemics complete the crash of the population, and reproduction is slowed for three or four generations, giving the resources ample time to recover. In some mammal species, crisis and crisis response recur regularly, leading to cycles of population growth and relapse, oscillating about a fixed mean. Population crisis response and population cycles have been equally prominent in the history of human societies. But in man successive advances in food production have made possible growing populations, though with every such advance population soon outgrew resources again. Hence human cycles have been superimposed on a rising curve, producing a saw-tooth graph. Because advances in food production amounted to sudden disturbances in the relations between human populations and their environments, the crisis response in man has failed to avert famine and resource damage. In the large human societies evolved since the coming of settled agriculture and cities, the basic effects of violence, epidemics, famine and resource damage have been mediated by such specifically human disasters as inflation, unemployment, and political tyranny. An account of past crises, periods of relative relief from population pressure, and resulting cycles, is given for a number of regions: China, North Africa and Western Asia, the northern Mediterranean, and north-western Europe. The paper ends with an account of the present world-wide population crisis, and the solution made possible by Malthus's discovery that, unlike animals, we can choose to check population growth by reducing the birth-rate, instead of raising the death-rate, as in other mammals, by the population crisis response. PMID:11130632

  1. Imaginary populations

    A. Martínez–Abraín

    2010-01-01

    Full Text Available A few years ago, Camus & Lima (2002 wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002, that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologists often forget "to acknowledge that many study units are neither natural nor even units in terms of constituting a population system", and hence claimed that we "require much more accuracy than in past decades in order to be more effective to characterize populations and predict their behaviour". They stated that this is especially necessary "in disciplines such as conservation biology or resource pest management, to avoid reaching wrong conclusions or making inappropriate decisions". As a population ecologist and conservation biologist I totally agree with these authors and, like them, I be¬lieve that greater precision and care is needed in the use and definition of ecological terms. The point I wish to stress here is that we ecologists tend to forget that when we use statistical tools to infer results from our sample to a population we work with what statisticians term "imaginary", "hypothetical" or "potential" popula¬tions. As Zar (1999 states, if our sample data consist of 40 measurements of growth rate in guinea pigs "the population about which conclusions might be drawn is the growth rates of all the guinea pigs that conceivably might have been administered the same food supplement under identical conditions". Such a population does not really exist, and hence it is considered a hypothetical or imaginary population. Compare that definition with the population concept that would be in our minds when performing such measurements. We would probably assume that our study population consisted of pigs (not the growth rates of pigs! and probably all the pigs at the farm we were sampling, rather than the all the growth rates of the pigs that might conceivably have been administered the same food. We overlook the fact that we are using the statistical tools to try to estimate ecological population para¬meters (and test specific hypotheses on the values of these population parameters but that the ecological population which is in our minds and the statistical (imaginary population of our tests need not necessarily be the same (and most often are not. So, to avoid wrong inferences (with wide–ranging consequences if we are dealing with decision–making processes we should do all we possibly can to ensure that our natural populations are as similar as possible to the imaginary populations of statisticians, or at least we should discuss our results within the framework in which our inference was developed. Statistics is not an ad hoc tool invented for us, but rather a tool that we have borrowed from statisticians for our purposes. We should always keep this in mind.

  2. Population policy.

    1987-03-01

    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to decrease fertility, control international migration, and modify the spatial distribution of the population. To reduce its population growth rate, Pakistan has adopted a multi-sectoral, multidimensional approach to family planning. The policy of the government of the Philippines is to bring the population growth rate in line with the availability of natural resources and employment opportunities. In its 5-year plan covering 1982-86, the government of the Republic of Korea emphasized social development, attempting to more fully integrate population and development policies and programs within relevant sectors. To reduce its population growth rate to 1.3% by 1992, the government of Thailand is expanding the reach of its family planning program. PMID:12341036

  3. Evaluacin de la actividad biocontroladora de Arthrobotrys sp. y Paecilomyces sp. sobre Meloidogyne javanica in vitro y bajo condiciones de invernadero en crisantemo (Drendranthema grandiflora Andernson

    Dvila Lida

    2005-06-01

    Full Text Available

    Para evaluar la accin biocontroladora de Arthrobotrys sp. y Paecilomyces sp. sobre huevos y larvas de Meloidogyne javanica en crisantemo, se realizaron pruebas in vitro y en invernadero. Se tomaron 500 larvas y 500 huevos del nematodo contenidos en suspensiones de agua estril y se trataron con concentraciones de 1,3 106; 1,4 107 y 6,4 106; 1,14 107 conidias/mL de Arthrobotrys sp. y Paecilomyces sp. Se observ bajo estereoscopio cada 24 horas, mientras la accin de los hongos sobre M. javanica se cuantific a las 72 horas de incubacin, con un ndice de control mayor de 50% sobre larvas y huevos. En invernadero se sembraron esquejes en suelo con compost estril bajo un diseo estadstico de bloques completos al azar. Los tratamientos fueron: hongos de forma individual y combinada; compost slo y combinado con cada hongo; carbofurn (Furadan; testigo patgeno y testigo absoluto. A los 45 das despus de la inoculacin se evalu el peso fresco de la raz, la longitud de la raz, el nmero de ndulos y el de individuos de M. javanica ambulatorios en 100 g de suelo. Mediante la prueba de Duncan (5% se determin que el tratamiento de hongos en forma combinada control a M. javanica, con un promedio de 18 ndulos en raz, y fue menos eficiente comparado con el control individual, con un promedio de 7 y 8 ndulos en raz respectivamente a los 45 das de transcurrida la infeccin. El compost no ejerci control sobre M. javanica pues present un promedio de 50 ndulos en raz; el tratamiento (Furadn exhibi un promedio de 25 ndulos en raz, mostrando diferencias significativas respecto a los tratamientos con los hongos nematfagos.

  4. Efecto de diferentes densidades poblacionales de Meloidogyne hapla sobre uchuva (Physalis peruviana L. en invernadero

    Niño Nancy Eunice

    2008-04-01

    Full Text Available

    Este estudio se realizó en el Centro de Investigaciones y Asesorías Agroindustriales de la Universidad de Bogotá Jorge Tadeo Lozano, Chía (Cundinamarca, bajo condiciones de invernadero, durante diez meses de cultivo. Se evaluó el efecto de diferentes densidades poblacionales de Meloidogyne hapla (0, 50, 100, 200, 500 y 1.000 larvas J2/100 cc de suelo, sobre parámetros productivos de la uchuva: altura de las plantas, diámetro de tallo, peso fresco, peso seco y biomasa de follaje, peso fresco de raíces, índice de nodulación radicular y peso fresco de frutos. Se hizo análisis de varianza, pruebas de contrastes y prueba de Tukey (α=0,05, en un diseño completamente aleatorio, con seis tratamientos y cinco repeticiones, mediante el programa SAS v.8.0. El tratamiento de 500 larvas J2/100 cc suelo fue el que más afectó la altura de las plantas, el diámetro del tallo, la biomasa de follaje, el peso fresco de raíces y presentó el índice de nodulación radical más alto. No se encontraron diferencias significativas entre los tratamientos inoculados con M. hapla , para peso fresco, peso seco de follaje y peso fresco de frutos, ni para el número de larvas J2 en suelo y masas de huevos. Mediante la ecuación: Y = m + (1–mZP-T propuesta por Seinhorst (1965, se estableció un límite de tolerancia de 50 larvas J2 de M. hapla /100 cc suelo, para peso fresco de raíces y un límite de tolerancia de 450 larvas J2 de M. hapla /100 cc suelo, para biomasa de follaje.

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

    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. PMID:26248710

  6. Pathogenicity Study and Nematoxic Properties of Some Plant Extracts on the Root-Knot Nematode Pest of Tomato, Lycopersicon esculentum (L. Mill

    T.I. Olabiyi

    2008-01-01

    Full Text Available In the screen house, tomato seedlings, cv. DT 69/257, grown in steam-sterilized soil were inoculated with graded inocula of 5,000; 10,000; 15,000; 20,000 and 25,000 eggs of root-knot nematode, Meloidogyne incognita. At inocula levels of 15,000; 20,000 and 25,000 eggs of M. incognita, number of leaf per plant, plant height, fruit yield and root galls were significantly reduced. In the field planted with tomato seedlings, aqueous extracts from the roots of marigold, nitta and basil plant were applied to root-knot nematode inoculated soil at four levels of 25,000; 500,000; 750,000 and 1,000,000 ppm concentrations, 10 mL per tomato stand. All the aqueous plant root extracts applied in the trials reduced root-knot nematode populations in the soil with corresponding increases in plant height, plant leaf and fruit yield over the control treatment. Significant reduction of root galls from the treated plots indicated effective root-knot nematode control by the aqueous root extracts.

  7. Evaluation of 31 potential biofumigant brassicaceous plants as hosts for three meloiodogyne species.

    Edwards, Scott; Ploeg, Antoon

    2014-09-01

    Brassicaceous cover crops can be used for biofumigation after soil incorporation of the mowed crop. This strategy can be used to manage root-knot nematodes (Meloidogyne spp.), but the fact that many of these crops are host to root-knot nematodes can result in an undesired nematode population increase during the cultivation of the cover crop. To avoid this, cover crop cultivars that are poor or nonhosts should be selected. In this study, the host status of 31 plants in the family Brassicaceae for the three root-knot nematode species M. incognita, M. javanica, and M. hapla were evaluated, and compared with a susceptible tomato host in repeated greenhouse pot trials. The results showed that M. incognita and M. javanica responded in a similar fashion to the different cover cultivars. Indian mustard (Brassica juncea) and turnip (B. rapa) were generally good hosts, whereas most oil radish cultivars (Raphanus. sativus ssp. oleiferus) were poor hosts. However, some oil radish cultivars were among the best hosts for M. hapla. The arugula (Eruca sativa) cultivar Nemat was a poor host for all three nematode species tested. This study provides important information for chosing a cover crop with the purpose of managing root-knot nematodes. PMID:25276003

  8. 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.

    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.

  9. Effects of water regime on the distribution of Meloidogyne graminicola and other root parasitic nematodes in a rice field toposequence and pathogenicity of M. graminicola on rice cultivar UPL R15

    Prot, Jean-Claude; Matias, D.M.

    1995-01-01

    Dans une toposéquence incluant des champs de riz pluvial, de riz de nappe et de riz irrigué, #Meloidogyne graminicola$ était présent dans les trois systèmes de production rizicole alors que #Pratylenchus zeae$ n'était présent que dans les champs de riz pluvial et #Hirschmanniella oryzae$ que dans les champs inondés. La prévalence et l'intensité moyenne de #M. graminicola$ étaient plus grandes dans les champs inondés que dans les champs exondés en permanence. Au cours d'une étude réalisée en s...

  10. Soil amendment with chopped or ground dry leaves of six species of plants for the control of Meloidogyne javanica in tomato under greenhouse conditions Incorporação ao solo de folhas secas picadas ou moídas de seis espécies de plantas para o controle de Meloidogyne javanica em tomateiro em casa de vegetação

    Everaldo Antônio Lopes

    2011-06-01

    Full Text Available Greenhouse experiments were conducted to evaluate the effect of soil amendment with chopped (1cm² or ground (1mm sieve dry leaves of assa-peixe (Vernonia polyanthes, lemon-grass (Cymbopogon citratus, eucalyptus (Eucalyptus citriodora, castor (Ricinus communis, mango (Mangifera indica or neem (Azadirachta indica for the control Meloidogyne javanica. Into the soil (Yellow red oxisol of each pot were added leaves (5g kg-1 of soil and 5,000 eggs of the nematode. After seven days, one tomato seedling "Santa Cruz Kada" was transplanted to each pot. The tomato root weight, galls and eggs/root system were determined 60 days after transplant. None of the soil amendments reduced gall or eggs, when applied as leaf pieces. However, all tested plant species reduced the gall number, when they were incorporated into the soil as powder, and maximum nematode suppression occurred in soil amended with neem leaves (61%. The amendment with ground leaves of castor, neem, eucalyptus and lemon-grass reduced the number of eggs, with maximum reduction occurring in soil amended with ground castor leaves (69%, evidencing that these organic amendments can be an alternative for M. javanica control in tomato. Further studies are required under field conditions to confirm the potential of these organic amendments on the control of M. javanica.Experimentos em casa de vegetação foram conduzidos com o objetivo de avaliar o efeito da adição ao solo de folhas secas picadas (1cm² ou trituradas (peneira de 1mm de assa-peixe (Vernonia polyanthes, capim-limão (Cymbopogon citratus, eucalipto (Eucalyptus citriodora, mamona (Ricinus communis, manga (Mangifera indica ou nim (Azadirachta indica para o controle de Meloidogyne javanica. Ao solo de cada vaso (latossolo vermelho-amarelo, foram adicionadas folhas (5g kg-1 de solo e 5.000 ovos do nematoide. Após sete dias, uma muda de tomateiro "Santa Cruz Kada" foi transplantada em cada vaso. O peso das raízes e os números de galhas e de ovos foram avaliados 60 dias após o transplantio. As folhas picadas de nenhuma planta reduziram o número de galhas e de ovos. Entretanto, as folhas de todas as plantas estudadas reduziram o número de galhas quando foram incorporadas ao solo na forma de pó e a máxima supressão foi obtida com as folhas de nim (61%. A adição ao solo de folhas trituradas de mamona, nim, eucalipto e capim-cidreira reduziu o número de ovos, com redução máxima após aplicação de folhas de mamona (69%, indicando que esses materiais orgânicos podem ser uma alternativa de controle de M. javanica em tomateiro. Novos estudos devem ser realizados em condições de campo para confirmar o potencial desses materiais orgânicos no controle de M. javanica.

  11. 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

    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, capim cidreira (Cymbopogon citratus, carqueja (Bacharis trimera, cavalinha (Equisetum sp., cinamomo (Melia azedarach, hortelã (Mentha sp., mamona (Ricinus communis, manjericão (Ocimum basilicum, melão-de-São-Caetano (Momordica charantia, arruda (Ruta graveolens, falso-boldo (Coleus barbatus, confrei (Symphitum officinalis, erva-de-bicho (Polygonum acre, feijão-de-porco (Canavalia ensiformis, funcho (Foeniculum vulgare, guiné (Petiveria alliacea, mentrasto (Ageratum conyzoides, mucuna-cinza (Mucuna pruriens e nim (Azadirachta indica. Água destilada foi adicionada ao solo como tratamento testemunha. Após 60 dias, avaliou-se a altura das plantas, o peso fresco da parte aérea e da raiz e os números de galhas e de ovos por sistema radicular. Os extratos de hortelã, bardana e mamona reduziram o número de galhas em 75,6%, 65,7% e 54,4%, e o número de ovos em 81,7%, 75,9% e 56,6%, respectivamente.

  12. Population neuroscience

    Paus, Tomas

    2013-01-01

    Is Newton's brain different from Rembrandt's? Does a mother's diet during pregnancy impact brain growth? Do adolescent peers leave a signature in the social brain? Does the way we live in our middle years affect how our brains age? To answer these and many other questions, we can now turn to population neuroscience. Population neuroscience endeavors to identify environmental and genetic factors that shape the function and structure of the human brain; it uses the tools and knowledge of genetics (and the ""omics"" sciences), epidemiology and neuroscience. This text attempts to provide a bridge

  13. Population dynamics

    Cooch, E. G.

    2004-06-01

    Full Text Available Increases or decreases in the size of populations over space and time are, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change over time in the abundance of some population is the simple difference between the number of additions (individuals entering the population minus the number of subtractions (individuals leaving the population. Of course, the precise nature of the pattern and process of these additions and subtractions is often complex, and population biology is often replete with fairly dense mathematical representations of both processes. While there is no doubt that analysis of such abstract descriptions of populations has been of considerable value in advancing our, there has often existed a palpable discomfort when the ‘beautiful math’ is faced with the often ‘ugly realities’ of empirical data. In some cases, this attempted merger is abandoned altogether, because of the paucity of ‘good empirical data’ with which the theoretician can modify and evaluate more conceptually–based models. In some cases, the lack of ‘data’ is more accurately represented as a lack of robust estimates of one or more parameters. It is in this arena that methods developed to analyze multiple encounter data from individually marked organisms has seen perhaps the greatest advances. These methods have rapidly evolved to facilitate not only estimation of one or more vital rates, critical to population modeling and analysis, but also to allow for direct estimation of both the dynamics of populations (e.g., Pradel, 1996, and factors influencing those dynamics (e.g., Nichols et al., 2000. The interconnections between the various vital rates, their estimation, and incorporation into models, was the general subject of our plenary presentation by Hal Caswell (Caswell & Fujiwara, 2004. Caswell notes that although interest has traditionally focused on estimation of survival rate (arguably, use of data from marked individuals has been used for estimation of survival more than any other parameter, save perhaps abundance, it is only one of many transitions in the life cycle. Others discussed include transitions between age or size classes, breeding states, and physical locations. The demographic consequences of these transitions can be captured by matrix population models, and such models provide a natural link connecting multi–stage mark–recapture methods and population dynamics. The utility of the matrix approach for both prospective, and retrospective, analysis of variation in the dynamics of populations is well–known; such comparisons of results of prospective and retrospective analysis is fundamental to considerations of conservation management (sensu Caswell, 2000. What is intriguing is the degree to which these methods can be combined, or contrasted, with more direct estimation of one or more measures of the trajectory of a population (e.g., Sandercock & Beissinger, 2002. The five additional papers presented in the population dynamics session clearly reflected these considerations. In particular, the three papers submitted for this volume indicate the various ways in which complex empirical data can be analyzed, and often combined with more classical modeling approaches, to provide more robust insights to the dynamics of the study population. The paper by Francis & Saurola (2004 is an example of rigorous analysis and modeling applied to a large, carefully collected dataset from a long–term study of the biology of the Tawny Owl. Using a combination of live encounters and dead recoveries, the authors were able to separate the relative contributions of various processes (emigration, mortality on variation in survival rates. These analyses were combined with periodic matrix models to explore comparisons of direct estimation of changes in population size (based on both census and mark–recapture analysis with model estimates. The utility of combining sources of information into analysis of populations was the explicit subject of the other two papers. Gauthier & Lebreton (2004 draw on a long–term study of an Arctic–breeding Goose population, where both extensive mark–recapture, ring recovery, and census data are available. The primary goal is to use these various sources of information to to evaluate the effect of increased harvests on dynamics of the population. A number of methods are compared; most notably they describe an approach based on the Kalman filter which allows for different sources of information to be used in the same model, that is demographic data (i.e. transition matrix and census data (i.e. annual survey. They note that one advantage of this approach is that it attempts to minimize both uncertainties associated with the survey and demographic parameters based on the variance of each estimate. The final paper, by Brooks, King and Morgan (Brooks et al., 2004 extends the notion of the combining information in a common model further. They present a Bayesian analysis of joint ring–recovery and census data using a state–space model allowing for the fact that not all members of the population are directly observable. They then impose a Leslie–matrix–based model on the true population counts describing the natural birth–death and age transition processes. Using a Markov Chain Monte Carlo (MCMC approach (which eliminates the need for some of the standard assumption often invoked in use of a Kalman filter, Brooks and colleagues describe methods to combine information, including potentially relevant covariates that might explain some of the variation, within a larger framework that allows for discrimination (selection amongst alternative models. We submit that all of the papers presented in this session indicate clearly significant interest in approaches for combining data and modeling approaches. The Bayesian framework appears a natural framework for this effort, since it is able to not only provide a rigorous way to evaluate and integrate multiple sources of information, but provides an explicit mechanism to accommodate various sources of uncertainty about the system. With the advent of numerical approaches to addressing some of the traditionally ‘tricky’ parts of Bayesian inference (e.g., MCMC, and relatively user–friendly software, we suspect that there will be a marked increase in the application of Bayesian inference to the analysis of population dynamics. We believe that the papers presented in this, and other sessions, are harbingers of this trend.

  14. Stellar Populations

    Peletier, Reynier

    2012-01-01

    This is a summary of my lectures during the 2011 IAC Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School was {\\it Secular Evolution of Galaxies} I mostly concentrate on nearby galaxies, which are best suited to study this theme. Of course, the understanding of stellar populations is intimately connected to understanding the formation and evolution of galaxies, one of the great outstanding problems of astronomy. We are currently in a situation where very large observational advances have been made in recent years. Galaxies have been detected up to a redshift of 10. A huge effort has to be made so that stellar population theory can catch up with observations. Since most galaxies are far away, information about them has to come from stellar population synthesis of integrated light. Here I will discuss how stellar evolution theory, together with observations in our Milky Way and Local Group...

  15. Populations games

    Křivan, Vlastimil

    2015-01-01

    Roč. 2, č. 1 (2015), s. 14-19. ISSN 2367-5233. [Featuring International Conferences Biomath 2015. Blagoevgrad, 14.06.2015-19.06.2015] R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : populations dynamics

  16. Variabilidade genética de acessos de araçazeiro e goiabeira suscetíveis e resistentes a Meloidogyne enterolobii

    Aline das Graças Souza

    2014-05-01

    Full Text Available A goiabeira representa uma importante atividade frutícola no Brasil, com mercado cada vez maior. Porém, desde 1989 vêm sendo relatados severos danos à cultura, causados pelo nematóide Meloidogyne enterolobii. Uma das alternativas para solucionar esse problema é a utilização de porta-enxertos com resistência a este patógeno. Este trabalho teve por objetivo a caracterização molecular, com marcadores RAPD, de acessos de Psidium testados quanto à resistência a M. enterolobii e quanto à compatibilidade como porta-enxertos para as goiabeiras comerciais. Foram testados 30 primers, dos quais 19 forneceram resultados nítidos para a amplificação. Foram gerados 163 fragmentos, dos quais 86 polimórficos (63,0%. Em média, cada iniciador produziu 8,6 fragmentos, dos quais 5,4 apresentaram polimorfismo. A análise de agrupamento foi realizada por espécie, os acessos de Psidium sp apresentaram a formação de dois grupos, um formado pelo acesso A-UFLA e o segundo subdividido em quatro subgrupos, sendo os acessos com maiores distâncias genéticas A-Ufla, resistente a M. enterolobii, A-Ufla4 e A-Ufla5, ambos suscetíveis ao nematoide em questão, todos coletados em Lavras-MG, com similaridade aproximada de 66%. Na análise de agrupamento, dos treze acessos de P.cattleyanum, foi possível constatar a formação de dois grandes grupos. Um formado por três acessos suscetíveis a M. enterolobii (A-20.2, A-10.1 e A-9.2 e outro grupo formado por dez acessos. Os acessos se agruparam, conforme a região de origem, em seis grupos, sendo que o mais divergente é originário da região de Lavras - MG, com 0,65 de similaridade, onde as distâncias genéticas variaram de 0,88 a 0,65. Dos treze acessos de P. guineense, todos suscetíveis a M. enterolobii, sendo 12 oriundos de Recife e um de Pelotas (A-14.1 e agruparam-se em dois grupos com similaridades variando de 0,59 a 0,83. Quanto ao estudo de diversidade entre os acessos de goiabeiras, a maior distância genética foi detectada entre o acesso G-Ufla com 0,71 Lavras-MG.

  17. Bacteriophage populations

    Bacteriophages are ubiquitous to the rumen ecosystem; they have a role in nitrogen metabolism through bacterial lysis in the rumen, they may help to regulate bacterial population densities, be an agent for genetic exchange and be of use in biocontrol of bacterial populations through phage therapy. In Chapter 2.1, classical methodologies to enable the isolation, enumeration, storage and morphological characterization of phages were presented. In addition to these classic procedures, molecular biological techniques have resulted in a range of methodologies to investigate the type, topology and size of phage nucleic acids, to fingerprint individual phage strains and to create a profile of ruminal phage populations. Different phage families possess all the currently identified combinations of double-stranded or single-stranded RNA or DNA and may also possess unusual bases such as 5-hydroxymethylcytosine (found in T-even phage) or 5- hydroxymethyluracil and uracil in place of thymidine. In all morphological groups of phage except the filamentous phages, the nucleic acid is contained within a head or polyhedral structure, predominantly composed of protein. Filamentous phages have their nucleic acid contained inside the helical filament, occupying much of its length. Many of the procedures used with phage nucleic acids and double-stranded (ds) DNA, in particular, are not specific to ruminal phages but are the same as in other areas where nucleic acids are investigated and are covered elsewhere in the literature and this chapter. Most applications with rumen phages are similar to those reported for phages of non-ruminal bacteria and are covered in general texts such as Maniatis et al. In this chapter, we will concentrate on aspects of methodology as they relate to ruminal phages

  18. Indian populations

    Spahni,J

    1974-01-01

    Le Prof. J.C. Spahni qui a parcouru les Andes, Vénezuela etc. parle de ses expériences et connaissances qu'il a vécu au cours des 14 ans parmi les populations indiennes de la Cordillière des Andes. Il a ramené des objets artisanals indiens lesquels l'auditoire peut acquérir. L'introduction-conférence est suivi d'un film, commenté par lui-même; après l'entracte il y un débat-dialogue avec le public.

  19. Obteno de bactrias para a o biocontrole de Meloidogyne javanica por meio de aquecimento de solo e tratamento com filtrado de razes de plantas antagonistas a fitonematides Obtaining bacteria for the biocontrol of Meloidogyne javanica by heating soil and treating it with root filtrates from plants antagonistic to nematodes

    Cleia F.S. Fabry

    2007-02-01

    Full Text Available Cinco amostras de solo com alto teor de matria orgnica (10,14 dag/kg de 1 kg cada foram autoclavadas (120 C/1h, cinco foram aquecidas em forno de microondas a 660 watts e 2450 Hz por 4 min e cinco no foram aquecidas. Razes de Mucuna aterrima, Crotalaria juncea, Tagetes erecta e Lycopersicon esculentum foram maceradas separadamente em liquidificador baixa velocidade durante 30 s em 1000 mL de gua e peneiradas. As suspenses resultantes foram adicionadas s amostras de solos as quais foram acondicionadas em saco plstico e submetidas aos trs tratamentos trmicos e posteriormente mantidas a 28 C por 24 h. Setenta e oito isolados bacterianos foram obtidos das amostras de solo por diluio em srie e submetidos seleo para o biocontrole de M. javanica. Sementes de tomate foram microbiolizadas por imerso em suspenso de propgulos de cada uma das culturas e semeadas em substrato dentro de tubetes em casa de vegetao. As mudas resultantes foram inoculadas com 400 ovos do nematide, cada. O isolado UFV-6 de Escherichia coli reduziu o nmero de galhas em maior magnitude (80% ao passo que o isolado UFV-8 de Citrobacter freundii foi o mais eficiente na reduo do nmero de ovos (83%. A identificao dos isolados foi feita por anlise de cidos graxos esteres de metil e testes bioqumicos.Five samples of 1 kg each of organic soil (10.14 dag/kg were autoclaved at 120 C for 1 hour, five were heated in a 660 watt and 2450 Hz microwave oven at full power for 4 min, and five were not heat-treated. Roots of Mucuna aterrima, Crotalaria juncea, Tagetes erecta and Lycopersicon esculentum were macerated, separately, in 1000 ml of tap water in a blender at low speed for 30 s, then sieved. Each of the resulting suspensions or just tap water (control treatment was poured on one of the different soil samples inside a plastic bag and stored at 28 C for 24 h. Seventy-eight bacterial isolates were obtained from the soil samples by serial dilution and selected for a subsequent assay for the biocontrol of Meloidogyne javanica. Tomato seeds were soaked in suspension of each bacterial isolate, then sowed in substrate inside plastic tubes in the greenhouse. The seedlings were each inoculated with 400 eggs of the nematode. The isolate UFV-6 of Escherichia coli reduced the number of galls to the highest extent (80%, and UFV-8 of Citrobacter freundii was the most effective in reducing number of eggs (83%. The identification of the isolates was done by fatty acid analyses and biochemical tests.

  20. Effect of Emamectin Benzoate on Root-Knot Nematodes and Tomato Yield

    Cheng, Xingkai; Liu, Xiumei; Wang, Hongyan; Ji, Xiaoxue; Wang, Kaiyun; Wei, Min; Qiao, Kang

    2015-01-01

    Southern root-knot nematode (Meloidogyne incognita) is an obligate, sedentary endoparasite of more than 3000 plant species, that causes heavy economic losses and limit the development of protected agriculture of China. As a biological pesticide, emamectin benzoate has effectively prevented lepidopteran pests; however, its efficacy to control M. incognita remains unknown. The purpose of the present study was to test soil application of emamectin benzoate for management of M. incognita in laboratory, greenhouse and field trials. Laboratory results showed that emamectin benzoate exhibited high toxicity to M. incognita, with LC50 and LC90 values 3.59 and 18.20 mg L-1, respectively. In greenhouse tests, emamectin benzoate soil application offered good efficacy against M. incognita while maintaining excellent plant growth. In field trials, emamectin benzoate provided control efficacy against M. incognita and resulted in increased tomato yields. Compared with the untreated control, there was a 36.5% to 81.3% yield increase obtained from all treatments and the highest yield was received from the highest rate of emamectin benzoate. The results confirmed that emamectin benzoate has enormous potential for the control of M. incognita in tomato production in China. PMID:26509680

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

    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 fitoparásitos en plantas de Vitis vinifera L. var ‘Chardonnay’ sobre dos portainjertos (K5BB, SO4 y ‘Chardonnay’ sin injertar como testigo, en tres diferentes suelos aluviales de la zona central de Chile. Los suelos fueron dos Inceptisoles del Valle de Casablanca (Región de Valparaíso, uno sin estructura, con una zona de densificación en profundidad (S1, y otro de textura predominante arenosa (S3; un tercer suelo correspondió a un Mollisol mejor estructurado (S2, en la Comuna de Melipilla (Región Metropolitana. Los suelos fueron caracterizados física y morfológicamente y los géneros de nematodos fueron identificados y contabilizados bajo lupa estereoscópica. ‘Chardonnay’ tuvo las mayores poblaciones de Meloidogyne spp. aunque sólo significativas en el suelo S2. Las poblaciones de Xiphinema spp. y Mesocriconema xenoplax no fueron suficientemente representativas como para asociarlas a diferencias de suelo o uso de portainjerto. Meloidogyne spp. se relacionó inversamente con el contenido de arena, sin embargo, positivamente con la mayor estructuración del suelo. Las regresiones Stepwise fueron útiles al relacionar las poblaciones de nematodos con múltiples factores edáficos.

  2. Population, Population Density, and Technological Change

    Klasen, Stephan; Nestmann, Thorsten

    2004-01-01

    In a model on population and endogenous technological change, Kremer combines a short-run Malthusian scenario where income determines the population that can be sustained, with the Boserupian insight that greater population spurs technological change and can therefore lift a country out of its Malthusian trap. We show that a more realistic version of the model, which combines population and population density, allows deeper insights into these processes. The incorporation of population densit...

  3. Pathogenicity Study and Nematoxic Properties of Some Plant Extracts on the Root-Knot Nematode Pest of Tomato, Lycopersicon esculentum (L.) Mill

    Olabiyi, T. I.

    2008-01-01

    In the screen house, tomato seedlings, cv. DT 69/257, grown in steam-sterilized soil were inoculated with graded inocula of 5,000; 10,000; 15,000; 20,000 and 25,000 eggs of root-knot nematode, Meloidogyne incognita. At inocula levels of 15,000; 20,000 and 25,000 eggs of M. incognita, number of leaf per plant, plant height, fruit yield and root galls were significantly reduced. In the field planted with tomato seedlings, aqueous extracts from the roots of marigold, nitta and basil plant were a...

  4. Análise da variabilidade genética de acessos de Psidium spp. (Myrtaceae avaliados quanto à reação a Meloidogyne enterolobii¹

    Eduardo José Almeida

    2012-06-01

    Full Text Available Este trabalho teve por objetivo a caracterização molecular de 13 acessos de Psidium spp. (Myrtaceae identificados previamente quanto à reação ao nematoide da goiabeira. A extração do DNA das amostras foi executada conforme o protocolo de Shillito e Saul (1988. Os marcadores moleculares do tipo fAFLP, foram obtidos utilizando-se do 'fAFLP Regular Plant Genomes Fingerprinting Kit' (Applied Biosystems do Brasil Ltda. onde foram testadas 24 combinações seletivas de primers, das quais 18 apresentaram amplificação que gerou 272 marcadores polimórficos. Para a análise dos marcadores, foram utilizados os softwares GeneScan (ABI Prism versão 1.0 e Genotyper (ABI Prism versão 1.03, e os dados coletados foram transformados em matriz binária que foi analisada no software PAUP (Phylogenetic Analysis Using Parcimony - versão 3.01. Foram também calculados índices de distância genética intra e interespecífica entre os materiais. Verificou-se que os marcadores AFLP foram eficientes na discriminação dos acessos entre si, bem como apontou similaridade genética entre os acessos identificados como resistentes ao nematoide Meloidogyne enterolobii, característica esta passível de exploração no futuro.

  5. Efficacy of Soil Amendment with Leaf Powder of Hyptis suaveolens (L. Poit in the Control of Meloidogyne javanica (Treub Chitwood on the African Yam Bean, Sphenostylis stenocarpa (Hochst Ex A. Rich Harms

    Christopher C. Onyeke

    2014-01-01

    Full Text Available Studies were carried out in screen house to determine the effects of different inoculum densities (2,000 and 4,000 eggs of Meloidogyne javanica and different levels (15, 30, 45, 60 and 75 t ha-1 of leaf powder of Hyptis suaveolens soil amendment on the pathogenicity of M. javanica on African yam bean. Results showed that organic soil amendment with H. suaveolens improved on the growth of plants infected with eggs of M. javanica as against the infected plants but unamended. It was also observed in this study that higher soil amendment levels (>30 t ha-1 led to sharp progressive decline in the fresh shoot and root weights of amended plants, which indicates possible phytotoxicity of H. suaveolens leaf powder at amendment levels above 30 t ha-1. H. suaveolens leaf powder amendment reduced significantly (p?0.05 the number of galls, egg masses, gall index and egg mass index as the amendment levels increased at both low and high inoculum densities. M. javanica reduced significantly (p?0.05 the number of nodules in infected test plants compared to the uninfected controls. This study also revealed that the pathogenicity of M. javanica was more at high inoculum density generally. Conclusively, this study has shown that application of H. suaveolens as soil amendment reduced the pathogenicity of M. javanica and improved on the growth parameters of the test plant but at higher levels (above 30 t ha-1 it became phytotoxic and highly nematicidal.

  6. Wittgensteins ‘Lebensform’: een terra incognita?

    Eijzenga, H.

    2008-01-01

    In dit artikel heb ik gesteld dat de dilemma’s ten aanzien van culturele incommensurabiliteit waarmee zowel universalisten als relativisten te maken krijgen vermeden kunnen worden door uitwerking van Wittgensteins ‘übersichtliche Darstellung’ (overzichtelijke weergave) waarmee Wittgenstein in de samenhang van zijn totale werk de notie ‘Lebensform’ (levensvorm) heeft verhelderd. Ik betoog dat menselijke uitingen begrepen moeten worden als de locale uitdrukking van aan alle menselijke levensvor...

  7. Control of Nematode Disease of Eggplant (Solanum aethiopicum L. Using Manure

    Stephen Adekunle Abolusoro

    2014-01-01

    Full Text Available Pot experiment was conducted in the year 2010 and repeated in 2011 to examine the effects of organic manure (poultry, cow dung, domestic waste and inorganic manure (NPK 15:15:15 on the yield, soil and root population of Meloidogyne incognita that infected Ethiopian eggplant Solanum aethiopicum in a greenhouse at Kabba College of Agriculture, Ahmadu Bello University, Kabba, Nigeria. Each of the organic manure was applied as soil amendment at the rate of 5 t/ha and the inorganic fertilizer (NPK was applied at the rate of 200 kg/ha while there was an untreated control that acted as standard check. The experimental design was a completely randomized design comprising of five treatments including control and each of the treatments was replicated four times. The results of the experiment showed that all the organic manures considered and NPK fertilizer were effective in suppressing nematode negative effects on the plant as manifested in improved yield, reduced soil and root population as well as in reduced gall index of the organic and inorganic manure treated plants compared with the control. The mean fruit yield of the manure treated plant was 18+1, of NPK fertilizer treated ones was 17, while the average fruit number in untreated control was 6.5. The organic and inorganic manures treated plants had bigger fruit size compared with control and were significantly different from the control. The soil and root population as well as root gall index were reduced in all the manure treatments compared with the control and they were significantly different from the control. The results of this experiment confirmed that organic manure can be utilized to manage root-knot nematode (M. incognita in soil.

  8. Dicty_cDB: Contig-U05758-1 [Dicty_cDB

    Full Text Available 905 sequences; 5,674,871 total letters Score E Sequences producing significant alignments: (bits) Val... BAC end sequ... 58 2e-04 1 ( CN577956 ) re48f02.y1 Meloidogyne incognita femal...Zea mays genomic clone ZM... 44 3.2 1 ( ES349891 ) PPMGS85 P. papatasi adult femal..., chromosome 6, clone:... 42 6.3 2 ( CN578243 ) re52a10.y1 Meloidogyne incognita female SMART pGE... 38 8.1 2 ( AC222067 ) Bos ta...othetica... 57 3e-07 AY086451_1( AY086451 |pid:none) Arabidopsis thaliana clone 2518 mR... 56 4e-07 EF085697

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

    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 bauruensis only var. Abura. Invasions by meadow-nematodes were equally observed in the two varieties concerned. In this paper, the study of M. javanica bauruensis n. subsp. is made with all the details possible. It differs from the typical subspecies (M. javanica javanica (Treub, 1885 Chitwood, 1949, in having : a eggs usually wider (37.0-52.5 : 31.0-40.0 micra; 6 stylet of larvae somewhat longer (11.0-11.6 :10.0 micra; c neck of larvae longer (b1 = 6.1-6.5 :b = 6.3-8.0; d head of male with a single post-labial annule instead of the two or three present in the typical subspecies; e lateral lines in the perineal pattern less evident and not extending to cervical region, with some striae extending unbroken from dorsal to ventral sectors; and, f higher arch in the perineal pattern, composed of marked wavy to zig-zag striae. In the population studied, several males were found for which the term intersex is applied. The less evident alteration that was seen affects only the shape of the male body, which is considerably thicker in its posterior portion and visibly shorter in its total length. The lateral fields are wider at the latitude of the thick portion, where additional incisures can be counted. In the most advanced case of intersexuality observed besides the same alteration in the shape of the body, there is a vulva and traces of a vagina very well defined. Some data about the M. incognita population obtained in association with M. javanica bauruensis are also presented. - Such a population only differed from that studied by Chitw r ood (1 in having shorter and more slender larvae and males with shorter spicules. Very short males were also observed their total length lying between 690 and 900 micra.

  10. Predicting Population Curves.

    Bunton, Matt

    2003-01-01

    Uses graphs to involve students in inquiry-based population investigations on the Wisconsin gray wolf. Requires students to predict future changes in the wolf population, carrying capacity, and deer population. (YDS)

  11. Interação dos fungos micorrízicos arbusculares Glomus etunicatum e Gigaspora margarita e o nematóide das galhas Meloidogyne javanica em tomateiro

    COFCEWICZ ELIS T.

    2001-01-01

    Full Text Available A produtividade do tomateiro pode ser severamente reduzida pelo parasitismo dos nematóides das galhas, amplamente distribuídos nas áreas de produção hortícola. Em condições de casa de vegetação, avaliou-se o efeito da interação entre duas espécies de fungos micorrízicos arbusculares (MA, Glomus etunicatum e Gigaspora margarita e o nematóide das galhas, Meloidogyne javanica, sobre o crescimento e nutrição do tomateiro (Lycopersicon esculentum cv. Floradade. A infecção por M. javanica reduziu a massa de matéria seca da parte aérea das plantas inoculadas. A redução foi menos acentuada em plantas colonizadas com G. etunicatum (12%, comparadas às plantas colonizadas com G. margarita (32% e testemunha (24%. Plantas colonizadas com G. etunicatum apresentaram maior massa de matéria seca e número de frutos comparadas aos demais tratamentos. A produção de frutos foi menos afetada pelo nematóide nas plantas inoculadas com G. etunicatum. A concentração e o conteúdo de P na parte aérea não foram alterados pelo nematóide nas plantas colonizadas por G. etunicatum, mas foram reduzidos nas plantas colonizadas com G. margarita e testemunhas. O número de ovos e juvenis de segundo estádio de M. javanica foi maior nas plantas colonizadas por fungos MA, comparadas às não micorrizadas. A maior tolerância observada nas plantas colonizadas com G. etunicatum ao nematóide das galhas, possivelmente está associada à maior estabilidade na absorção de P.

  12. Characterization of Root-Knot Nematode Resistance in Cowpea and Utilization of Cross-Species Platforms in Legume Genomics

    Das, Sayan

    2008-01-01

    Cowpea (Vigna unguiculata L. Walp) is an important food and fodder legume worldwide. Cowpea is grown extensively in sub-Saharan Africa where it is an important staple. Root-knot nematode (RKN, Meloidogyne spp.) is a significant pest in cowpea. Several sources of resistance to RKN have been identified in cowpea, including the widely used Rk gene. As part of a study to elucidate the mechanism of Rk -mediated resistance, the histological response to avirulent M. incognita feeding of a resistant ...

  13. Drip Irrigation as a Delivery System for Infestation of Field Plots with Nematodes

    Becker, J. O.; Monson, M.; Van Gundy, S. D.; Schroth, M N

    1989-01-01

    A drip irrigation delivery system was used to infest field sites with the plant-parasitic root-knot nematodes, Meloidogyne incognita. Juvenile or egg inocula passed through the system without blockage of emitters or harm to the nematodes. Field sites so infested were available for experimentation. Delivery of approximately 5 x 10? to 10? juveniles or 10? to 3 x 10? eggs per emitter through the drip system resulted in heavy root galling of tomatoes planted next to the drip emitters. Nematodes ...

  14. Effectiveness and safety of botanical pesticides applied in black pepper (Piper nigrum) plantations

    Wiratno

    2008-01-01

    Black pepper (Piper nigrum L) is an important commodity of Indonesia, which has been cultivated since the 6th century. The plant plays an important role in local economies since 95% of the plantations are cultivated by smallholder farmers. Because of this important economic value, proper plant production is highly valued. One of the central factors to maintain plant production is how to control key pests of the plant such as the root-knot nematode, Meloidogyne incognita, the stem borer, Lopho...

  15. Involvement of nitric oxide in the jasmonate-dependent basal defense against root-knot nematode in tomato plants

    Zhou, Jie; Jia, Feifei; Shao, Shujun; Zhang, Huan; Guiping LI; Xia, Xiaojian; Zhou, Yanhong; Yu, Jingquan; Shi, Kai

    2015-01-01

    Jasmonic acid (JA) and nitric oxide (NO) are well-characterized signaling molecules in plant defense responses. However, their roles in plant defense against root-knot nematode (RKN, Meloidogyne incognita) infection are largely unknown. In this study, we found that the transcript levels of the JA- and NO-related biosynthetic and signaling component genes were induced after RKN infection. Application of exogenous JA and sodium nitroprusside (SNP; a NO donor) significantly decreased the number ...

  16. Elevated CO2 Influences Nematode-Induced Defense Responses of Tomato Genotypes Differing in the JA Pathway

    Sun, Yucheng; Yin, Jin; Cao, Haifeng; Li, Chuanyou; Kang, Le; Feng GE

    2011-01-01

    Rising atmospheric CO2 concentrations can affect the induced defense of plants against chewing herbivores but little is known about whether elevated CO2 can change the induced defense of plants against parasitic nematodes. This study examined the interactions between the root-knot nematode Meloidogyne incognita and three isogenic tomato (Lycopersicon esculentum) genotypes grown under ambient (390 ppm) and elevated (750 ppm) CO2 in growth chambers. In a previous study with open-top chambers in...

  17. Potential of Foliar, Dip, and Injection Applications of Avermectins for Control of Plant-Parasitic Nematodes

    Jansson, Richard K.; Rabatin, Susan

    1998-01-01

    Studies were conducted to determine the potential of two avermectin compounds, abamectin and emamectin benzoate, for controlling plant-parasitic nematodes when applied by three methods: foliar spray, root dip, and pseudostem injection. Experiments were conducted against Meloidogyne incognita on tomato, M. javanica on banana, and Radopholus similis on banana. Foliar applications of both avermectins to banana and tomato were not effective for controlling any of the nematodes evaluated. Root dip...

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

    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 ...

  19. Red Food Coloring Stain: New, Safer Procedures for Staining Nematodes in Roots and Egg Masses on Root Surfaces

    Thies, Judy A.; Merrill, Sharon B.; Corley, E. Luther

    2002-01-01

    Acid fuchsin and phloxine B are commonly used to stain plant-parasitic nematodes in roots and egg masses on root surfaces, respectively. Both stains can be harmful to both the user and the environment and require costly waste disposal procedures. We developed safer methods to replace both stains using McCormick Schilling red food color. Eggs, juveniles, and adults of Meloidogyne incognita stained in roots with red food color were equally as visible as those stained with acid fuchsin. Egg mass...

  20. Root-knot Nematode Problem of Some Winter Ornamental Plants and Its Biomanagement

    Khan, Mujeebur Rahman; Khan, Shahana M.; Mohide, Faya

    2005-01-01

    A microplot study under field conditions was carried out during 2 consecutive years to assess the effect of root-knot nematode infection (2,000 Meloidogyne incognita eggs/kg soil) on three winter ornamental plants: hollyhock (Althea rosea), petunia (Petunia hybrida), and poppy (Papaver rhoeas). Effects of root-dip treatment with the biocontrol agents Pochonia chlamydosporia, Bacillus subtilis, and Pseudomonas fluorescens and the nematicide fenamiphos were tested. The three ornamental species ...

  1. Strip-tilled Cover Cropping for Managing Nematodes, Soil Mesoarthropods, and Weeds in a Bitter Melon Agroecosystem

    Marahatta, Sharadchandra P.; Wang, Koon-Hui; Sipes, Brent S.; Hooks, Cerruti R. R.

    2010-01-01

    A field trial was conducted to examine whether strip-tilled cover cropping followed by living mulch practice could suppress root-knot nematode (Meloidogyne incognita) and enhance beneficial nematodes and other soil mesofauna, while suppressing weeds throughout two vegetable cropping seasons. Sunn hemp (SH), Crotalaria juncea, and French marigold (MG), Tagetes patula, were grown for three months, strip-tilled, and bitter melon (Momordica charantia) seedlings were transplanted into the tilled s...

  2. Efeitos de diferentes níveis de matéria orgânica no solo e de inóculo sobre a interação planta-Meloidogyne spp. e a produção massal de Pasteuria penetrans Effects of cow manure levels in the soil and inoculum concentration on the plant-Meloidogyne spp. interaction and on the mass production of Pasteuria penetrans

    Fábio Ramos Alves

    2007-12-01

    Full Text Available Foram estudados os efeitos de quatro proporções de esterco de curral no solo, 0, 20, 33 e 50% (V:V, e três níveis de inóculo de Meloidogyne spp. (3.000, 6.000 e 9.000 J2 por planta na concentração de fenóis em raízes de tomateiro, no desenvolvimento das fêmeas, nas células gigantes induzidas por esses patógenos e na infecção e reprodução de Pasteuria penetrans. O experimento foi conduzido em casa-de-vegetação, em delineamento inteiramente ao acaso com doze repetições, sendo avaliado 50 dias após a inoculação das plantas. O tamanho médio das fêmeas do nematóide foi maior quando as plantas foram inoculadas com 3.000 J2. Maior percentual de fêmeas infectadas por P. penetrans foi observado quando não se utilizou esterco no substrato ou quando as plantas foram inoculadas com 3.000 J2. As plantas inoculadas com 9.000 J2 e cultivadas no substrato com 20% de esterco foram as que produziram mais endósporos. A concentração de fenóis nas raízes aumentou à medida que se acrescentou esterco de curral ao substrato. As células gigantes de plantas cultivadas no substrato com 33 e 50% de esterco apresentaram menores número, tamanho e quantidade de núcleos. O aumento da proporção de esterco de curral ao substrato causou aumento nas concentrações de fenóis nas raízes, fato que foi deletério às células gigantes, prejudicial ao desenvolvimento do nematóide e à reprodução de P. penetrans.The effects of four different proportions of cow manure, 0, 20, 33 and 50% (V:V and three Meloidogyne spp. inoculum levels (3,000; 6,000 and 9,000 J2 per plant on the phenol concentration in the tomato roots, in the nematode female development, the giant cells induced by the nematode and on the reproduction of Pasteuria penetrans were investigated. The experiment was carried out in greenhouse, in a completely randomized design with twelve replicates, and evaluated 50 days after inoculation. The size of nematode females was higher when the plants were inoculated with 3,000 J2. Higher proportion of females infected by P. penetrans was observed when the plants were cultivated in the substrate without cow manure or when plants were inoculated with 3,000 J2. Plants inoculated with 9,000 J2 and cultivated on substrate with 20% of cow manure yielded more endospores. The phenolic content in the roots increased as higher proportions of cow manure were used in the substrate or when the plants were inoculated with the highest number of nematodes. The giant cells of plants cultivated on substrate with 33 and 50% of cow manure were less numerous, smaller and had less nuclei number, demonstrating the deleterious effect of organic amendments on the giant cells, on the nematodes and on the P. penetrans reproduction.

  3. Populous: A tool for populating ontology templates

    Jupp, Simon; Iannone, Luigi; Klein, Julie; Owen, Stuart; Schanstra, Joost; Stevens, Robert; Wolstencroft, Katy

    2010-01-01

    We present Populous, a tool for gathering content with which to populate an ontology. Domain experts need to add content, that is often repetitive in its form, but without having to tackle the underlying ontological representation. Populous presents users with a table based form in which columns are constrained to take values from particular ontologies; the user can select a concept from an ontology via its meaningful label to give a value for a given entity attribute. Populated tables are mapped to patterns that can then be used to automatically generate the ontology's content. Populous's contribution is in the knowledge gathering stage of ontology development. It separates knowledge gathering from the conceptualisation and also separates the user from the standard ontology authoring environments. As a result, Populous can allow knowledge to be gathered in a straight-forward manner that can then be used to do mass production of ontology content.

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

    Juan Carlos lvarez-Hernndez

    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 Sangra 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.

  5. Alvaro uribe populism and neo-populism

    Fierro C., Marta I.

    2014-01-01

    The paper develops two concepts, populism and neo-populism, to examine the government and the figure of president Alvaro Uribe Velez.The text presents the management of the media, economic policy, dealing with the Supreme Court, the relationship with the NGOs and, finally, elements of illegality and illegitimacy in their government.

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

    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.

    2015-01-01

    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 25C/21C, 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 35C 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. PMID:26170475

  7. Solarização do solo e biofumigação no cultivo protegido de tomate The effect of solarization and biofumigation on tomatoes under protected cultivation

    Mírian Josefina Baptista

    2006-03-01

    Full Text Available Foi avaliado o efeito da fumigação com brometo de metila, biofumigação e da solarização sobre a população do fitonematóide Meloidogyne sp., a incidência de plantas daninhas e características químicas do solo em ambiente protegido para o plantio de tomate. Foram testados os tratamentos: resíduos de couve-flor e de brócolos (2% v/v, cama de aves (2% v/v, fumigação com brometo de metila e solo não tratado, todos com e sem solarização. O período de solarização foi de dois meses e, em seguida, foi feito o plantio dos híbridos de tomate Alambra, resistente a Meloidogyne incognita (gene Mi, e Duradoro (suscetível. O banco de sementes de plantas daninhas no solo foi avaliado em amostras retiradas do perfil de 0 a 20 cm de profundidade, com amostragem das plantas daninhas emergidas aos 30 dias após o transplante do tomate. Para as análises químicas foram retiradas amostras de solo após a solarização e biofumigação. A solarização do solo, uso de cama de aves e fumigação com brometo de metila reduziram a população de nematóides no solo e o número de massas de ovos nas raízes dos dois híbridos avaliados. O híbrido Alambra, no entanto, apresentou massa seca e fresca da parte aérea, altura e peso de frutos, na primeira colheita, maiores nos solos solarizados, respondendo melhor à solarização que o 'Duradoro'. A fumigação com brometo de metila e a solarização reduziram a viabilidade das sementes e a sobrevivência de plantas daninhas. A solarização aumentou os teores de fósforo e de cobre e reduziu os teores de zinco no solo.A greenhouse experiment was carried out to test the effects of solarization and biofumigation on the population of the plant parasitic nematode Meloidogyne sp., on the incidence of weeds and on soil chemical properties in protected areas for the cultivation of tomatoes. Brassica residues (broccoli and cauliflower and chicken litter amendments (2% v/v, methyl bromide and no amendment were evaluated with or without solarization. The tomato hybrids 'Alambra', Meloidogyne incognita resistant (gene Mi, and 'Duradoro' (susceptible, were planted after two months soil solarization. Weed seed bank and weed survival were evaluated by soil sampling and germination of viable seeds and by sampling the emerged plants 30 days after transplanting of the tomato seedlings. Soil samples were analyzed for their chemical properties after solarization and biofumigation. Soil solarization, chicken litter amendment and methyl bromide treatments reduced nematode populations and the number of egg masses on both tomato hybrids. However, 'Alambra' presented significantly higher total fresh and dry weight, plant height and fruit weight in comparison to 'Duradoro'. 'Alambra' was more responsive to treatments than 'Duradoro'. Methyl bromide fumigation and solarization reduced the number and survival of weed seeds in the soil. Solarization increased levels of P and Cu, and reduced levels of Zn in the soil.

  8. Glaucoma in Asian Populations

    ... Involved News About Us Donate In This Section Glaucoma In Asian Populations email Send this article to ... lower than in their Asian counterparts. Normal Tension Glaucoma affects Japanese Japanese populations, however, have a substantially ...

  9. Modeling Exponential Population Growth

    McCormick, Bonnie

    2009-01-01

    The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

  10. Controlling Population with Pollution

    Browne, Joseph

    2010-01-01

    Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.

  11. Soil organisms associated to the weed suppressant Crotalaria juncea (fabaceae) and its importance as a refuge for natural enemies / Organismos de solo associados supressora de plantas daninhas Crotalaria juncea (fabaceae) e sua importncia como refgio para inimigos naturais

    W.S, Tavares; I, Cruz; R.B, Silva; M.L.C, Figueiredo; F.S, Ramalho; J.E, Serro; J. C, Zanuncio.

    2011-09-01

    Full Text Available Organismos de solo desempenham um importante papel em cultivos orgnicos de Crotalaria juncea (Fabaceae) e esto associados com a conservao natural do ambiente. O presente estudo teve como objetivo investigar a populao de organismos de solo no cultivo orgnico de C. juncea, bem como sua importn [...] cia como um refgio para inimigos naturais. Dalbulus maidis (Hemiptera: Cicadellidae), Diabrotica sp. (Coleoptera: Chrysomelidae), Doru luteipes (Dermaptera: Forficulidae), Gryllus assimilis (Orthoptera: Gryllidae), Lagria villosa (Coleoptera: Lagriidae), Melanotus sp. (Coleoptera: Elateridae), Meloidogyne incognita (Tylenchida: Heteroderidae), Nephila clavipes (Araneae: Nephilidae), Orius insidiosus (Hemiptera: Anthocoridae), Pheidole sp. (Hymenoptera: Myrmicidae), Phyllophaga sp. (Coleoptera: Scarabeidae), Procornitermes sp. (Isoptera: Termitidae), Solenopsis sp. (Hymenoptera: Formicidae) e Utetheisa ornatrix (Lepidoptera: Arctiidae) foram identificados em C. juncea. Os organismos que foram encontrados durante um perodo de trs meses em 144 trincheiras em C. juncea foram as espcies de pragas (84,47%) e inimigos naturais (15,53%). Inimigos naturais tiveram uma mdia de 11,89 indivduos por 1,08 m de solo cultivado com C. juncea. A abundncia de organismos na fase de vagem (5,49%) de C. juncea foi menor do que nas fases vegetativa (83,50%) e florao (11,01%). Plantas de C. juncea podem ser usadas como parte de um sistema de cultivo para o Manejo Integrado de Pragas. Abstract in english Soil organisms play an important role in organic crops of Crotalaria juncea (Fabaceae) and are associated with the natural conservation of the environment. The present study was aimed to investigate the population of soil organisms in the organic culture of C. juncea, as well as its importance as a [...] refuge for natural enemies. Dalbulus maidis (Hemiptera: Cicadellidae), Diabrotica sp. (Coleoptera: Chrysomelidae), Doru luteipes (Dermaptera: Forficulidae), Gryllus assimilis (Orthoptera: Gryllidae), Lagria villosa (Coleoptera: Lagriidae), Melanotus sp. (Coleoptera: Elateridae), Meloidogyne incognita (Tylenchida: Heteroderidae), Nephila clavipes (Araneae: Nephilidae), Orius insidiosus (Hemiptera: Anthocoridae), Pheidole sp. (Hymenoptera: Myrmicidae), Phyllophaga sp. (Coleoptera: Scarabeidae), Procornitermes sp. (Isoptera: Termitidae), Solenopsis sp. (Hymenoptera: Formicidae), and Utetheisa ornatrix (Lepidoptera: Arctiidae) were identified in C. juncea. The organisms that were found during a 3-month period in 144 trenches in C. juncea were pest species (84.47%) and natural enemies (15.53%) as well. Natural enemies had an average of 11.89 individuals per 1.08 m of soil cultivated with C. juncea. The abundance of organisms in the pod stage (5.49%) of C. juncea was lower than that in the vegetative (83.50%) and flowering (11.01%) stages. Crotalaria juncea plants can be used as part of a crop system for Integrated Pest Management.

  12. Establishment of orchards with black polyethylene film mulching: effect on nematode and fungal pathogens, water conservation, and tree growth.

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

    1992-12-01

    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

  13. EL INJERTO HERBCEO: ALTERNATIVA PARA EL MANEJO DE PLAGAS DEL SUELO / VEGETABLE GRAFTING: ALTERNATIVE FOR THE MANAGMENT OF SOIL PEST

    Farah Mara, Gonzlez; A, Hernndez; A, Casanova; T, Depestre; Lucila, Gmez; Mayra G, Rodrguez.

    2008-08-01

    Full Text Available Las hortalizas mantenidas en invernaderos son muy afectadas por los nematodos formadores de agallas Meloidogyne spp. Estos organismos causan considerables prdidas en los rendimientos en este tipo de instalaciones. Numerosas alternativas de manejo han sido empleadas con xito en el mundo, entre ella [...] s, el injerto es una prctica cultural, que constituye un importante componente de los sistemas de Manejo Integrado de Plagas en el cultivo protegido de solanceas (tomate, pimiento y berenjena) y cucurbitceas (meln, pepino y sanda). Se utilizan con xito en diversos pases portainjertos hbridos de origen silvestre o especies cultivadas resistentes a Meloidogyne spp. (M. incognita, M. arenaria y M. javanica).En Cuba el Instituto de Investigaciones Hortcolas Liliana Dimitrova" (La Habana), evalu el comportamiento de portainjertos forneos, nacionales (hbridos, variedades y especies silvestres), frente a Meloidogyne incognita raza 2. Se obtuvo que los genotipos de tomate LAO'7002' y LAO'7003' fueron resistentes al igual que el pimiento `LINEM' y la especie silvestre Solanum torvum. En este artculo los autores realizan un anlisis de la informacin existente en esta temtica para la posibilidad de emplear esta prctica, investigar su efectividad en los cultivos protegidos de Cuba y preparar a los tcnicos vinculados al trabajo en estas instalaciones. Abstract in english Vegetables grown under greenhouses are very affected the root-knot nematodes Meloidogyne spp. This pest causes considerable yield losses in that kind of facilities. Several management alternatives have been successfully used in the world; among them grafting is a cultural practice that constitutes a [...] n important component of the IPM systems on sheltered cultivation of Solanaceae (tomato, pepper and eggplant) and Cucurbitaceae (melon, cucumber and watermelon). Using resistant rootstocks (hybrids, cultivated species and other wild species of the same gene resistant to Meloidogyne spp. (M. incognita, M. arenaria and M. javanica) have been successfully used in many countries. In Cuba, researchers from the "Liliana Dimitrova" Horticulture Research Institute evaluated the behaviour of commercial and national rootstocks (hybrids, varieties and other wild species) against Meloidogyne incognita race 2. Resistant rootstocks of tomato `LAO-7002', `LAO-7003'; of pepper `LINEM' and wild species Solanum torvum were identified. In this paper, an analysis of the existent information about this topic was carried out in order to study the possibility of employing this practice; researching its effectiveness on sheltered crops and training technicians working in these facilities.

  14. Population Empirical Bayes

    Kucukelbir, Alp; Blei, David M.

    2014-01-01

    Bayesian predictive inference analyzes a dataset to make predictions about new observations. When a model does not match the data, predictive accuracy suffers. We develop population empirical Bayes (POP-EB), a hierarchical framework that explicitly models the empirical population distribution as part of Bayesian analysis. We introduce a new concept, the latent dataset, as a hierarchical variable and set the empirical population as its prior. This leads to a new predictive density that mitigat...

  15. Measurably evolving populations

    Drummond, Alexei James; Pybus, Oliver George; Rambaut, Andrew; Forsberg, Rene; Rodrigo, Allen Gerard

    2003-01-01

    processes through time. Populations for which such studies are possible � measurably evolving populations (MEPs) � are characterized by sufficiently long or numerous sampled sequences and a fast mutation rate relative to the available range of sequence sampling times. The impact of sequences sampled through...... time has been most apparent in the disciplines of RNA viral evolution and ancient DNA, where they enable us to estimate divergence times without paleontological calibrations, and to analyze temporal changes in population size, population structure and substitution rates. Thus, MEPs could increase our...

  16. Befolkningsudviklingen (Population Development)

    Nørgaard, Jørgen

    The article takes the 1972 report, The Limits to Growth as its starting point, briefly explaining the Systam Dynamics model used for the report's analyses. Focus is on the important role of population. The simple model of I = PxAxT, where I is the environmental Impact, P population, A is the...

  17. Negative Drift in Populations

    Lehre, Per Kristian

    An important step in gaining a better understanding of the stochastic dynamics of evolving populations, is the development of appropriate analytical tools. We present a new drift theorem for populations that allows properties of their long-term behaviour, e.g. the runtime of evolutionary algorithms...

  18. World Population Crisis.

    Ehrlich, Paul R.; Ehrlich, Anne H.

    1986-01-01

    Rapid population growth, rising competition for resources, and increasing environmental deterioration are intertwined factors in the human predicament that feed political tensions and conflicts of the late twentieth century. Outlines dimensions of this predicament (including data on population, growth, military spending, quality of life, and…

  19. Population and population policy: French model

    Parant Alain

    2008-01-01

    Full Text Available Generations born today, or at least are trying to be, are scarcer than before all over the world. This decrease in the number of children is affecting modern societies in many spheres. If it was to be supported by efficient policies, it could be the source of a general improvement of life conditions. However, if this phenomenon continues or becomes drastic, it could ultimately lead to slower or faster demographic ageing, which could endanger many social heritages. Public intervention must, in that case, impinge much deeper, but without guarantees for a complete, if not permanent, success. The introductory part of the article is dedicated to the concept "demographic revolution" which was developed in 1934 by the French politician and demographer Adolphe Landry, in order to mark the development of a demographic regime which is characterized by a universally accepted practice of birth control, which represents a response for the essential concern for life standard improvement, not only for the parents but their children as well. But then, birth control is the primary cause of population ageing. The article further presents some of the most striking traits of the current French demographic situation, as its future development. France has a positive balance of population exchange with the remaining part of the world, as most of the Western European countries, but still the greatest part of its demographic increase is obtained from a larger number of births than deaths. Because of this, France is often seen as a real demographic paradise in Europe, whose population is decreasing and ageing. This image is certainly flattering, but it is becoming very contradictory after an analysis of long-term trends of fertility indicators and population ageing. The third part of the article, with the situation in France in focus, investigates the modalities and limitations of activities which a society, faced with demographic ageing and decreasing number of children, can apply: policies or simple "adjusting along the way" to demographic processes measures; policies and measures which are more intervening - even in the completely private sphere of birth-giving, and directed towards the limitation of some very unfavorable effects and not towards the change of strongly expressed tendencies of population ageing.

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

    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.

  1. [African population in history].

    Yang, S

    1984-11-29

    The growth rate of the African population has been fluctuating throughout history, affected by political, social, and economic events. 6000 years ago, the majority of the population was based in North Africa, because farming had been developed there. However, between the 11th and the 16th centuries, there was a constant decline in the population of that region, due to invasions from Europe and the black plague. During the same period, the population in the area south of the Sahara grew rapidly, as people there had gone into the iron tool period and farming had been developed. From the 16th to the mid-17th Century, population growth was considerable in Africa; more people had learned the technology of irrigation, corn and potatoes had been introduced from South America, and colonialism was not yet an issue. From the mid-17th to the mid-19th Century, there was no growth, due to the slave trade and wars between tribes. One estimate sets the direct and indirect loss during this period, as a result of the slave trade, at 100 million people. From the 1850s to the end of World War I, population growth started up again, chiefly influenced by the fact that the slave trade had essentially come to a half and modern medical care had become available on the continent. However, in central Africa, the region which suffered the worst blow from the slave trade, growth was very slow, while in East Africa the population was declining because of wars between colonists and natives, as well as natural disasters. Increases in population during this period were a result of immigration from Europe and India. From the end of World War I to the present, growth has been rapid, given improvements in medical services and standards of living, while most of the former colonies became independent after the 1950s. Consequently, almost all African countries are under great pressure now with regard to their populations. PMID:12159345

  2. Predation and caribou populations

    Dale R. Seip

    1991-10-01

    Full Text Available Predation, especially wolf (Canis lupus predation, limits many North American caribou (Rangifer tarandus populations below the density that food resources could sustain. The impact of predation depends on the parameters for the functional and numerical response of the wolves, relative to the potential annual increment of the caribou population. Differences in predator-avoidance strategies largely explain the major differences in caribou densities that occur naturally in North America. Caribou migrations that spatially separate caribou from wolves allow relatively high densities of caribou to survive. Non-migratory caribou that live in areas where wolf populations are sustained by alternate prey can be eliminated by wolf predation.

  3. Stellar population synthesis revisited

    The isochrone synthesis method is introduced as a population synthesis method for galaxies. The method permits accurate distributions of stars in the theoretical color-magnitude diagram to be computed for any stellar population and thereby circumvent the problems faced by earlier techniques. A set of evolutionary tracks extending from the ZAMS up to the beginning of the white-dwarf cooling sequence is compiled to optimize the models. Comparison of model predictions with observational data leads to the conclusion that the isochrone synthesis can reproduce the observed colors of stellar populations of ages from a few tens of millions of yr to a Hubble time. 78 refs

  4. Population dynamics of the Taimyr reindeer population

    B.M. Pavlov; L.A. Kolpashchikov; V.A. Zyryanov

    1996-01-01

    The Taimyr herd of wild reindeer (Rangifer tarandus tarandus L.) is one of the three largest herds of wild Rangifer in the world, and numbered about 600 000 in 1993. The herd grew continuously from 1959 to 1990, and is now stable due primarily to intensive commercial harvesting along the Khatanga River. Meat from the commercial harvest is processed and sold in population centers in the northern Krasnoyarsk region, particularly Norilsk. The herd has expanded its range to about 1.5 million km2,...

  5. Populated Places of Iowa

    Iowa State University GIS Support and Research Facility — This coverage contains points that represent populated places, ie. cities, towns, villages or any other named place where people live. The coverage was developed...

  6. Modeling Honey Bee Populations.

    Torres, David J; Ricoy, Ulises M; Roybal, Shanae

    2015-01-01

    Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population. PMID:26148010

  7. Hispanic or Latino Populations

    ... 75 years reported being up-to-date with colorectal cancer screening in 2010 than their non-Hispanic adult ... Health Promotion (NCCDPHP) Division of Population Health (DPH) Preventive Health & Health Services Block Grant Promoting Health Equity ...

  8. Bridged Race Population Estimates

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

  9. Parallel grid population

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  10. Market Squid Population Dynamics

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains population dynamics data on paralarvae, juvenile and adult market squid collected off California and the US Pacific Northwest. These data were...

  11. Hanford Area 2000 Population

    This report was prepared for the U.S. Department of Energy (DOE) Richland Operations Office, Surface Environmental Surveillance Project, to provide demographic data required for ongoing environmental assessments and safety analyses at the DOE Hanford Site near Richland, Washington. This document includes 2000 Census estimates for the resident population within an 80-kilometer (50-mile) radius of the Hanford Site. Population distributions are reported relative to five reference points centered on meteorological stations within major operating areas of the Hanford Site - the 100 F, 100 K, 200, 300, and 400 Areas. These data are presented in both graphical and tabular format, and are provided for total populations residing within 80 km (50 mi) of the reference points, as well as for Native American, Hispanic and Latino, total minority, and low-income populations

  12. AMPHIBIAN POPULATION DYNAMICS

    Agriculture has contributed to loss of vertebrate biodiversity in many regions, including the U.S. Corn Belt. Amphibian populations, in particular, have experienced widespread and often inexplicable declines, range reductions, and extinctions. However, few attempts have been made...

  13. Population III Hypernovae

    Smidt, Joseph; Whalen, Daniel J.; Even, Wesley; Wiggins, Brandon K.; Johnson, Jarrett L.; Fryer, Chris L.

    2014-01-01

    Population III supernovae have been of growing interest of late for their potential to directly probe the properties of the first stars, particularly the most energetic events that are visible near the edge of the observable universe. But until now, hypernovae, the unusually energetic Type Ib/c supernovae that are sometimes associated with gamma-ray bursts, have been overlooked as cosmic beacons at the highest redshifts. In this, the latest of a series of studies on Population III supernovae,...

  14. The politics of population.

    Wolfson, M

    1986-03-01

    This article suggests some of the principal factors behind the decisions by an increasing number of countries deciding that the achievement of their national objectives required a policy for population, and the way that they are likely to work out. By 1983, 35 developing countries had an official policy to reduce their population growth rate, and in 34 others, the government supported family planning activities--usually for reasons of health or as a human right. The number is remarkable given the many compelling reasons that governments have for not attempting anything so difficult as to modify demographic trends. The future results of population programs, in social and economic terms, are very difficult to quantify, thus defying cost-benefit analysis of the desirability of investing resources in this area, rather than in something else. There are also powerful political reasons why a government might well hesitate before embarking on a policy to reduce the nation's fertility. At the very least, it implies government interference in the most private and personal of human relations, an invasion of human rights, and a disturbance of the traditional patterns of society and behavior. For many countries that are pursuing a policy to limit population growth, the decision has been taken only after the grievous consequences of not having such a policy have already become manifest. The critical question is how soon a government will make the connection among political disobedience, economic and social distress, and the population explosion, and adopt a population policy. Although the number of developing countries that have officially proclaimed a strongly pro-natalist population policy is relatively small, many have Marxist governments. Overall, governments have several strategies at their disposal: 1) improving the accessability and the quality of the service; 2) promoting population education and family planning motivation (with the assistance of the media, folk art, and personal persuasion); and 3) applying a judicious mixture of incentives and disincentives. PMID:12340889

  15. Modeling Honey Bee Populations

    Torres, David J.; Ricoy, Ulises M.; Roybal, Shanae

    2015-01-01

    Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we st...

  16. Extinction of oscillating populations

    Smith, Naftali R.; Meerson, Baruch

    2016-03-01

    Established populations often exhibit oscillations in their sizes that, in the deterministic theory, correspond to a limit cycle in the space of population sizes. If a population is isolated, the intrinsic stochasticity of elemental processes can ultimately bring it to extinction. Here we study extinction of oscillating populations in a stochastic version of the Rosenzweig-MacArthur predator-prey model. To this end we develop a WKB (Wentzel, Kramers and Brillouin) approximation to the master equation, employing the characteristic population size as the large parameter. Similar WKB theories have been developed previously in the context of population extinction from an attracting multipopulation fixed point. We evaluate the extinction rates and find the most probable paths to extinction from the limit cycle by applying Floquet theory to the dynamics of an effective four-dimensional WKB Hamiltonian. We show that the entropic barriers to extinction change in a nonanalytic way as the system passes through the Hopf bifurcation. We also study the subleading pre-exponential factors of the WKB approximation.

  17. Vietnam's population: current notes.

    Fraser, S E

    1984-06-01

    In an effort to curb the population growth rate, currently estimated at 2.5%/year, the government of Vietnam has stepped up its campaign to implement a national family planning program. 1979 census figures indicate a population of 52.76 million. There is increasing government awareness of the interaction between population growth, employment, and manpower utilization. The demographic realities of Vietnam necessitate a drastic decrease in fertility rates and family size, a redistribution of the population either through internal migration to new economic zones or transborder migration, and a more efficient use of land and exploitation of natural and human resources to support the growing population. Assuming a natural increase rate of less than 2% by 1984-85, the government estimates a total population of nearly 60 million by the end of 1985. It is hoped that a natural growth rate of 1% can be attained in the early 1990s, to achieve a population size below 75 million by the year 2000. However, if the 3-child family remains the norm, the population will approach 80-85 million by 2000. Changes in shortterm fertility patterns seem unlikely without a carefully thought out and sensitively implemented policy involving a deliberate scheme of incentives and disincentives. The Vietnam Fatherland Front (VFF) has recognized the need for a more regorous fertility control campaign and has requested that the Council of Ministers set up a coordinated population and family planning structure with direct linkages from Hanoi to provincial governments and communal administrations. Also recommended were regulations on birth control, population targets and norms, and a system of incentives and disincentives. Data from family planning services in Ho Chi Minh City for 1976-82 suggest a recent decline in IUD, condom, and pill users, largely as a result of procurement difficulties. The number of abortions has also declined because of successful family planning education. The ideal family size is 2 children, but 3 are permitted. User resistance, inadequate education, and a lack of teaching materials have made this ideal difficult to attain among rural families in the southern provinces. PMID:12339701

  18. Population dynamics of the Taimyr reindeer population

    B.M. Pavlov

    1996-01-01

    Full Text Available The Taimyr herd of wild reindeer (Rangifer tarandus tarandus L. is one of the three largest herds of wild Rangifer in the world, and numbered about 600 000 in 1993. The herd grew continuously from 1959 to 1990, and is now stable due primarily to intensive commercial harvesting along the Khatanga River. Meat from the commercial harvest is processed and sold in population centers in the northern Krasnoyarsk region, particularly Norilsk. The herd has expanded its range to about 1.5 million km2, but movements to the southwestern portion of the winter range may have been impeded by pipeline, road and railroad construction, and winter shipping of ore on the lower Yenisey River.

  19. Population explosion, social change.

    Pethe, V P

    1983-01-26

    The issue of whether overpopulation is the cause of poverty or vice versa is a sham controversy. Both population explosion and poverty are symptoms of a deeper problem, i.e., the incapacity of the socioeconomic system and the international economic order to put into service modern science and technology for an optimal utilization of this planet's vast resources for economic development. There is no question that population growth cannot be allowed to go unabated for an indefinite period, yet there is no reason for alarm. History shows that human adjustments in social behavior have always restored equilibria in every crisis in the progress of humankind. Neo-Malthusians fail to see this point. Instead, they try to create a scare by making unrealistic projections. There is no need for the incorrect and dangerous neo-Malthusian theory as a way to plead for checking population growth. There are 3 simple reasons why population growth should slow down: populations in most less developed countries have a size sufficiently large to make them militarily and economically viable and will not face serious problems in economic and social management if their populations get stabilized at the current levels; there are several advantages in changing attitudes and behavior patterns in respect to matters such as marriage age, family limitation, and spacing of children, and these are desirable in their own right besides their effect on reducing fertility and population growth; and a need exists to intervene on the side of fertility in order to maintain the longrun equilibrium of population size. In the past, equilibrium between mortality and fertility was achieved through the operation of natural factors. Now, with the reduction in mortality as a result of human intervention, it has become necessary to bring about a decline in fertility through human intervention. Human intervention in the control of fertility is a difficult and complex process. The solution to the population explosion is family planning, rapid economic development, and appropriate social transformation. The sooner this transformation occurs the closer humankind will be to the solution of the problems of poverty and overpopulation. PMID:12311997

  20. Frequency Population Growth Rate

    Nouralah Salehi Asfiji

    2012-10-01

    Full Text Available The Solow growth model assumes that labor force grows exponentially. That is not a realistic assumption. In generalized logistic equations that describes more accurately population growth. Economic growth is not a smooth process. Real GDP has fluctuations in the growth rate. We call these fluctuations business cycles. Business cycle theory came about from the failures of classical economics in being able to illuminate on the causes of the Great Depression. The logistic growth model to explain changes in population growth rates are not. In this paper a new analysis of the population growth rate in the frequency space is described with mathematical logic and economic reasoning, so that, firstly, to a higher level of capital per capita, or at least equal to the Solow growth model reaches Second, the limits of saturation (Carrying-Capacity is not, and ultimately, population growth rates have an impact on long-term per capita amounts. The initial classic assumption is changed in this article based on the available frequencies in the population growth equation.

  1. Intrinsically dynamic population models

    Robert Schoen

    2005-03-01

    Full Text Available Intrinsically dynamic models (IDMs depict populations whose cumulative growth rate over a number of intervals equals the product of the long term growth rates (that is the dominant roots or dominant eigenvalues associated with each of those intervals. Here the focus is on the birth trajectory produced by a sequence of population projection (Leslie matrices. The elements of a Leslie matrix are represented as straightforward functions of the roots of the matrix, and new relationships are presented linking the roots of a matrix to its Net Reproduction Rate and stable mean age of childbearing. Incorporating mortality changes in the rates of reproduction yields an IDM when the subordinate roots are held constant over time. In IDMs, the birth trajectory generated by any specified sequence of Leslie matrices can be found analytically. In the Leslie model with 15 year age groups, the constant subordinate root assumption leads to reasonable changes in the age pattern of fertility, and equations (27 and (30 provide the population size and structure that result from changing levels of net reproduction. IDMs generalize the fixed rate stable population model. They can characterize any observed population, and can provide new insights into dynamic demographic behavior, including the momentum associated with gradual or irregular paths to zero growth.

  2. Asymetric Pavlovian Populations

    Bournez, Olivier; Cohen, Johanne; Koegler, Xavier; Rabie, Mikael

    2011-01-01

    Population protocols have been introduced by Angluin et al. as a model of networks consisting of very limited mobile agents that interact in pairs but with no control over their own movement. A collection of anonymous agents, modeled by finite automata, interact pairwise according to some rules that update their states. Predicates on the initial configurations that can be computed by such protocols have been characterized as semi-linear predicates. In an orthogonal way, several distributed systems have been termed in literature as being realizations of games in the sense of game theory. We investigate under which conditions population protocols, or more generally pairwise interaction rules, correspond to games. We show that restricting to asymetric games is not really a restric- tion: all predicates computable by protocols can actually be computed by protocols corresponding to games, i.e. any semi-linear predicate can be computed by a Pavlovian population multi-protocol.

  3. Symbiotic Nitrogen Fixation of Two Soybean Genotypes as Affected by Root-Knot Nematode and Microsymbionts

    D.L. Coyne

    2007-01-01

    Full Text Available The ability of soybean to symbiotically fix Nitrogen (N was found to be substantially reduced (p≤0.05, after inoculation with root-knot nematode (Meloidogyne incognita. Galling, which is a commonly used indicator of root-knot crop damage, may provide less accurate information about reductions in the symbiotic N fixation of soybean. The experiments were undertaken in Nigeria in pots, using two soybean genotypes (TGx 1448-2E and TGx 1485-1D with differential susceptibility to nematode. The microsymbionts Glomus mosseae (200 spores, Bradyrhizobium japonicum (106 cells mL1 and Trichoderma pseudokoningii (6.8x107 spores were applied plant1. Treatments involving nematode inoculation had 1000 second-stage juveniles plant1. Ureide N (fixed N in stems and petioles, nodulation score and activity, nematode infection and arbuscular mycorrhizal colonization were assessed at harvest using standard methods. Regression and correlation analyses demonstrated that root nematode densities assessed at harvest were highly correlated negatively (p≤0.001 with Symbiotic N Fixation (SNF as measured from the ureide N. Results confirmed that inoculation of M. incognita reduced SNF, nodulation score, nodule activity and plant growth parameters. However, fixed N was not necessarily related to galling damage. Results indicated that nodulation score and galling may not be the most suitable parameters, by which levels of productivity or damage could be determined in the presence of Meloidogyne sp., but rather ureide N is a more accurate assessment of the effect of M. incognita on soybean.

  4. [Population problem, comprehension problem].

    Tallon, F

    1993-08-01

    Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur rapidly because the problems are urgent. PMID:12287360

  5. National population policy.

    1983-01-26

    India evolved a comprehensive national population policy in April 1967. The primary assumption behind this policy was that the population explosion was an offshoot of poverty and must be dealt with as a part of an overall design for a better life. Clear demographic goals were defined, and several programs were initiated as part of the policy in an effort to integrate family planning with the overall strategy of socioeconomic development. The following are among the more important features of the 1976 national population policy: 1) increase the marriage age from 15-18 years for girls and from 18 to 21 years for boys; 2) freeze the population figures at the 1971 level until the year 2001 for purposes of representation in the national parliament as well as for allocation of central assistance, devolution of taxes, and so forth to the States; 3) more attention to the education of girls; 4) a proper place for population education in the total system of education; 5) involvement of all ministries/departments of government in the family planning program; 6) increase in monetary compensation for sterilization; 7) institution of group awards as incentives for various organizations and bodies representing the people at local levels; 8) the intimate association of voluntary organizations with the implementation of the program; 9) more attention to research; and 10) greater use of motivational media, particularly in rural areas, for increasing acceptance of family planning. According to Indira Gandhi, the objective is not simply to curb population growth but to have happier and healthier families, which, in India's circumstances, means smaller families. In the 1st 5-year plan (1951-56) India's outlay on family planning (Rs. in crores) was 0.65. It had increased to 1010.00 by the 6th 5-year plan (1980-85). PMID:12312003

  6. Population and development.

    Pavlik, Z

    1995-01-01

    During the Paleolithic period, 10,000-100,000 people lived on the earth; their number exceeded 1 million at the beginning of the Neolithic period, reached 10 million during the Bronze Age, 100 million at the beginning of the Iron Age, 1 billion at the beginning of the 19th century, and 5.7 billion in 1995. The estimated global population will be 10 billion by the middle of the 21st century and is expected to stabilize at around 10-12 billion subsequently. Increased agricultural production helped bring about greater numbers of humanity and the advancement of society with a developing social hierarchy, although life expectancy was low at 22-28 years. In Europe, the Renaissance gradually evolved into the Industrial Revolution, and a demographic revolution accompanied this process. In some countries, population size increased more than five times. Eventually, mortality and fertility levels decreased and life expectancy increased. In Western civilization, increased individualism, secularization, compulsory school attendance, decreased agricultural population, emancipation of women, increased costs of raising children, and social and economic progress ensued. All this was preceded by 18th century conditions, when, in England, capital accumulation led to wealth on the one side and destitution on the other, giving rise to Malthus's famous theory. However, during the 19th century these social inequalities gradually evened out. After World War II, the question arose of whether the populations of other civilizations (Confucian, Japanese, Islamic, Hindu, Slavic-Orthodox, Latin American, and African) would also undergo a demographic transition and how soon. At any rate, developed country population size, as a percentage of global population, will drop from 22% to 13%, and that of Africa will increase from 12% to 26%, during the 21st century. PMID:12292830

  7. Having quality population.

    Ramos, F V

    1993-06-01

    This speech was delivered during Population and Development Week in the Philippines. Attention was drawn to population statistics: an annual growth rate of 2.3%, density of 202 persons/sq km, and an expected population of 75 million by the year 2000. Coupled with rapid population growth is the uneven distribution of wealth: the top 20% have over 50% of the total income and the lowest 20% have only 5% of the income. In such a social situation, it is women and children who are the most vulnerable. In cities, unemployment is high due to population growth and the migration of the rural poor. The rural poor living in areas of declining resources also move onto marginal uplands, which adds pressure to the already fragile ecology. Everyone must accept that the nation's problems are due to overpopulation. The government's development plans aim for sustainable growth, poverty alleviation, reduction in equality, generation of job opportunities, and achievement of social justice. People in government are determined to lead the Philippines toward a higher standard comparable with other dynamic Asian neighbors. The strategy is empowerment of the people. THe value is in the welfare of individuals and their families and the welfare of the nation. Couples have the right to manage their family size voluntarily and responsibly. The government's role is to provide adequate information on family planning in accordance with individual's religious convictions. Policies will also be directed to improved access to quality education, child survival, and maternal health, employment opportunities, and access and control over resources for people. There must be fuller participation of women in development. Support for the government's population program is sought from government officials, the private sector, and nongovernmental organizations. All provincial governors, city and municipal mayors, and all local executives will be directed to formulate population plans and to provide family planning information and services. Public funds will be sought for population management and family planning. A National Plan of Action will be strictly followed over the next 6 years. The people are urged to follow the example of the national leader, the late Rafael Montinola Sales, who was awarded, posthumously, the Sikatuna Degree of Datu. PMID:12286475

  8. [Population of Comoros].

    Tallon, F

    1985-01-01

    The 3 islands administered by the Federal Islamic Republic of Comoros had a total population of 335,150 in the 1980 census. The population grew at an annual rate of 3.3% after the 1966 census, but growth rates were slower on Grand Comoros than on the other 2 islands. 54.5% of the population lived in villages of less than 2000 inhabitants. There is not much rural-urban migration because of the lack of employment opportunities in urban areas. The age structure of Comoros is poorly known, and ages ending in 5 and especially in 0 are greatly overrepresented in the census. The proportion under age 15 has increased from 44.0% in 1966 to 47.2% in 1980. 96% of men and 98% of women marry. The average age at 1st marriage is 20.0 for women and 26.8 for men. The proportion of polygamous men has decreased from 24.9% in 1966 to 19.1% in 1980. Polygamy is more common among older men. Marriage is unstable because of the ease of divorce. 48.8% of persons aged 12 and over are illiterate. The active population numbered 99,463 in 1980, or 29.7% of the total. 73.6% of the active population was male, but female activity rates were probably underestimated. 13.3% of the population was unemployed. 65.3% of the active population was engaged in agriculture, 5.7% in fishing, and 4.1% in construction. The economic development of the 3 islands is uneven; Anjouan seems to be the poorest and least developed. Because of the poor quality of age and other data in the census, the method of Brass was used to estimate fertility levels. The resulting fertility rates per 1000 women were 134.5 for ages 15-19, 327.4 for those 20-24, 337.9 for those 25-29, 276.6 for those 30-34, 178.8 for those 35-39, 80.6 for those 40-44, and 74.7 for those 45-49. The general fertility rate was 219/1000, the crude birth rate was 46.0/1000, the total fertility rate was 7.05, and the crude reproduction rate was 3.41. Indirect methods yielded estimates for males, females, and the total population respectively of 16.4, 15.1, and 15.7 for general mortality, 132.4, 110.4, and 127.1 for infant mortality, and 54.2, 53.9, and 54.0 for life expectancy. Migration from 1 island to another is increasing, but is still relatively unimportant. Short-term population projections indicate total populations of 395,410 in 1985 and 466,277 in 1990. Long-term demographic prospects are bleak because of the young age structure and lack of employment opportunities. A population policy with a family planning component should be put in place if future economic and demographic disaster is to be averted. PMID:12341246

  9. [Population census, 1980].

    Suharto, S

    1980-12-01

    The author describes the types of data collected in the 1980 population census of Indonesia, considers the differences between the 1971 and 1980 censuses, and discusses which data and tables are scheduled to be published. A copy of the census questionnaire and an explanation of the concepts and definitions used are also included. PMID:12338729

  10. Ideology and population theory.

    Harvey, D

    1974-01-01

    The ideological and ethical foundations of population theory are examined in the light of the supposed eithical neutrality of scientific enquiry. The works of Malthus, Ricardo, and Marx are contrasted and it is shown that their theories of population resulted in each case from the adoption of a particular kind of method--empiricism in Malthus, normative analytic "model building" in Ricardo, and dialectical materialism in Marx. It is shown that a Malthusian or neo-Malthusian view of the population problem is inevitable if enquiry is founded in empiricism or in normative analytics. The well-known disagreement between Malthusian and Marxian viewpoints therefore has its foundation in method. Most modern enquiry into the population-resources problem is dominated by empirical and analytic (including systems theory) approaches and consequently arrives at neo-Malthusian conclusions. The final section analyses the consequences of adopting a neo-Malthusian view, and it is shown that in a world dominated by an elite, this can frequently bring about the political, social, and economic repression of a non-elite. It is concluded that the choice of scientific method does not produce unbiased results and that the dominance of a certain conception of scientific method leads to the scientific support of a viewpoint used to justify repression of the underprivileged in society. PMID:4448574

  11. Population II variables

    Statistics are reviewed for Population II pulsating variables in globular clusters and in the field, and current research programs are summarized. Included are Cepheids (including Anomalous Cepheids and Dwarf Cepheids), RV Tauri stars, and red variables (Mira, semiregular, and irregular variables), but not RR Lyraes

  12. Population and women's health.

    Abernethy, V

    1994-01-01

    Explanations of cultural patterns can be found in the economic context (carrying capacity) in which they develop. Population pressure explains the abuse of women throughout history and in modern times because overpopulation leads to devaluation of women's reproductive capacity. A cultural response to overpopulation includes practices that limit the numbers of women of reproductive age. Such practices foster son preference, which results in selective abortion, female infanticide, neglect and overwork of girls, dowry deaths, and discrimination against widows. The results of these practices are manifest in sex ratios that are culturally rather than naturally controlled and in demographic facts such as the calculation that 60 million females are missing in Asia alone (and perhaps more than 100 million worldwide). Women are also removed from a reproductive setting by being kidnapped or sold into prostitution or by being forced to adopt prostitution for economic survival. In cases where survival is threatened by environmental degradation and population growth, the most harsh cultural practices will emerge to adapt the population to the resources at hand. This situation creates an ethical dilemma posed by the problem of imposing Western values on a culture that is undertaking adaptive practices to insure its very survival. Ways to help women in these situation include limiting population growth humanely through family planning, provision of paid work to women, and creation of an environment that supports a small family ideal. Prosperity itself, through modernization, sometimes causes family sizes to increase. The most important intervention appears to be the provision of paid employment outside the home for women. On the other hand, large-scale wealth transfers and liberal immigration policies simply send signals that population pressure is a regional problem that can be alleviated by the international community. Increasing immigration to developed countries will place pressure on the women of those countries by increasing population. The fact that population size in the US is expected to double in 64 years already poses a threat to the status of US women who are not immune from cultural processes. PMID:10131273

  13. Liaoning: population success story.

    Jing, W; Ma, X

    1992-02-01

    The 1990 national census revealed that the population growth of Liaoning Province in China had been under control since the 1970s with a birth rate of 16.30/1000, a mortality rate of 6.59/1000, and a low rate of natural increase: 9.71/1000 in 1990. The total fertility rate (TFR) of women in 1989 was 1.50, much lower than the national average of 2.25. TFR has remained under the replacement level of 2.1 since 1980, greatly reducing the effect of the birth peaks in the 1950s and 1960s. Liaoning Province is situated in northeast China with a population of 39 million, 3.5% of the national total. Population density is 270 persons/sq km, which is 2.3 times the national average of 118 persons/sq km. The urban population comprises 51% of the total. A health survey conducted a Shenhe District of Shenyang City, the capital of the province, on children born between 1980 and 1989 showed that among 42,598 babies born in the 1st 5 years the disabled or those with birth defects made up 5.47/1000, however, among 36,993 babies born in the next 5 years these disorders accounted for only 1.70/1000. A course in population science has been offered in more than 80% of middle schools in Liaoning with the hope of influencing the reproductive behavior of the next generation. The Family Planning Association of Liaoning Province was established in 1983. More than 1600 branch family planning associations have been organized in the province with a membership of over 2 million. In core households in villages women in reproductive age are organized for self-education and self-management for a better implementation of family planning. PMID:12285648

  14. [The Marxist outlook on population].

    Qin, R

    1984-09-29

    Marxist population theory and world population are discussed. From his study of capitalist population theory Marx concluded, "In capitalist reproduction, poverty produces population," thus rejecting Malthusian population determinism theory and developing economic determinism. According to UN statistics, world population has stabilized since the middle of this century after having doubled every hundred years for the last 300; population in the developed countries showed a positive decrease and average net population growth of the developing countries also decreased. The premise of this paper is that population grows according to social economy development. During the last several hundred years, world wealth increased much faster than population; in the last 200 years alone, the population has increased fivefold, but wealth fortyfold. In addition, world population analysis reveals an inverse relationship between wealth and population in the developed and developing countries: the poorer the country, the greater the population. From this perspective, the study of population must begin with surplus labor. Accumulation of surplus production is the foundation of continuous social development and the basis for population growth. The major difference in methods between capitalist countries and China is that the capitalist-planned fertility affects the individual family while Chinese-planned fertility has the whole nation in mind. Human fertility is determined by the economic system. Private ownership determines the private nature of fertility and public ownership determines the public nature of fertility. Thus population development is determined by the accumulation of social wealth. PMID:12159280

  15. [Vietnam and its population].

    Veron, J

    1993-01-01

    Viet Nam's 1993 population of 72 million makes it the second largest country of Southeast Asia after Indonesia. Viet Nam's demographic transition is underway, but growth is still a rapid 2% annually, a sufficiently high rate to hinder socioeconomic development. The 1979 and 1989 censuses and the 1988 Demographic and Health Survey are the major recent sources of data on Viet Nam's population. Marriage is universal in Viet Nam. Men marry at 24.5 and women at 23.2 years on average. Fertility estimates based on nonadjusted census data indicate a total fertility rate for 1988-89 of 3.8 overall, 2.2 in urban areas, and 4.3 in rural areas. Regional differences resulting from contraceptive usage, educational differentials, and tabus regarding spacing are strong. The average household size is 5. Viet Nam's first fertility reduction policy was announced in 1963 and sought to improve the welfare of women to increase their productivity for the war effort. More recent family planning policies are based on the view that rapid demographic growth is one of the great obstacles to development. The objectives of the current policy are to reduce the growth rate to 1% by the end of the century, increase contraceptive prevalence, delay arrival of the first child, limit family size to 2 children or 3 for ethnic minorities, and increase birth intervals from 3 to 5 years. The program is voluntarist in nature but includes incentives and disincentives. Life expectancy at birth in 1989 was 67.5 years for women and 63 for men. Infant mortality was 37/1000, with regional differentials. The principal causes of hospital deaths are tuberculosis, malaria, and diarrhea. Objectives of the current health policy are to prevent infectious diseases, reinforce primary health care services, promote traditional medicine, achieve self-sufficiency in basic medicines, and improve environmental health and access to clean water. Viet Nam is one of the most densely populated Southeast Asian countries and is still 80% rural. The population is concentrated in the Red River delta, the Mekong delta, and the southeastern region including Ho Chi Minh City. The 4 main cities are Ho Chi Minh City with 3.2 million inhabitants,. Hanoi with 1.1 million, Hai Phong with 456,000, and Da Nang with 371,000. Although internal migration has not yet assumed great weight, there has been some rural exodus and movement from poor to richer regions. The policy of population redistribution to reduce density in the Red River delta and central coastal plain and to control city growth has led to some movement. 88% of the population over 10 was literate in 1989. Almost 75% of the population over age 13 is economically active. 71% of the economically active population is employed in agriculture, 12% in industry, and 7% in commerce. If current growth trends continue, Viet Nam is projected to have a population of 80 million in 2000 and 96 million in 2014. PMID:12178203

  16. Population and economics.

    Wright, W

    1995-06-01

    The first world consists of the developed industrial countries, the second consists of rapidly developing countries, and the third of less developed, largely pre-industrial countries. The economies of most developed countries in recent years have been relatively stagnant. Most people in the developed world therefore assume that the bottom of the business cycle has arrived and that an upturn will soon be forthcoming. With the exception of the USA and Chile, which have been moderately prosperous in the last few years, the bottom has persisted for a very long time. Indeed, the developed world is not caught in a conventional business cycle, but in something quite new and different. The first world is struggling to stay at the top of countries worldwide both economically and politically, but the second world is rapidly catching up. Populations in these latter countries are both better educated and willing to work harder per unit of capital compared to people in the first world. Marketplace forces and the communication highway are increasingly bring about a scenario in which the first and second worlds will be economic peers. Faced with increased competition from the second world and a larger number of countries capable of providing foreign aid to the third world, it should be clear that the first world will turn inward and reduce its annual aid contributions to less developed countries. It is, however, in the first world's interest to promote family planning toward the goal of reduced population growth. Developed countries should insist that a substantial fraction of whatever foreign aid is provided goes toward reducing the rate of population growth. The first priority should be to make contraceptives available and promote their use worldwide. Efforts should then be taken to empower women through educational and other programs. This approach will slow population growth and improve the economic productivity of both men and women. The Third World should also seriously address its own population problems, and stop looking to the day when their enormous populations will overwhelm the first world. PMID:12319518

  17. Opinions on population.

    1994-01-01

    Great friction currently exists between family planning advocates and institutions opposed to contraception or abortion on religious grounds as the time draws near to convene the 1994 UN International Conference on Population and Development. A rift is also open between those who understand rapid population growth as a symptom of deep social inequities and those who see it only as a disease unto itself. The Human Development Report 1994 notes that human development like women's education is often the most powerful contraceptive, while the Vatican complains that the conference is about cultural imperialism. Planned Parenthood, however, counters that the Vatican has its head in the sand with regard to modern life and lifestyles. Other short comments are listed by the Executive Coordinator of the conference, the founder of Scientific American, and the Schiller Institute. PMID:12318900

  18. On optimal population paths

    Lane, John S

    1977-01-01

    The overall purpose of this monograph is to integrate and critically evaluate the existing literature in the area of optimal joint savings population programs. The existing diverse presentations are all seen to be discussions within a unified framework. The central problem is to compare the desirability of alternative inter-temporal sequences of total savings and population sizes. Of critical importance is whether one regards persons as the fundamental moral entities or whether one takes Sidgwick's viewpoint that something good being the result of one's action is the baSic reason for dOing anything. The latter viewpoint is consistent with defining a complete social preference ordering over these alternative sequences. Since part of one's interest is to evaluate the consequences of various ethical beliefs a com­ parative study of several such orderings is presented; in particular the Mill-Wolfe average utilitarian, and Sidgwick-Meade classical utilitarian) formulations. A possible problem with the social pref...

  19. Populations at risk - Paediatrics

    Disasters affect all segments of the population. Many subsets of the general adult population have specific needs and vulnerabilities. One group with specific needs and which is always at high risk in disasters is children. The physiological, anatomical, developmental and psychological requirements in children differ from those of adults. Disaster planning must recognise and adapt to this. For the past 3 years, the Centre of Excellence in Emergency Preparedness (CEEP) has been developing a document that will outline specific paediatric issues in disasters and provide general (and, where possible, specific) guidelines for Canadian health-care providers and disaster planners. This paper discusses special issues of emergency preparedness for children and reviews the content of the document being developed at CEEP. (authors)

  20. Population, environment and development.

    Karkal, M

    1994-06-01

    Western development models label subsistence economies, which do not participate in the market economy on a grand scale and do not consume commodities produced for and distributed through the market, to be poor. Yet, subsistence does not always indicate a low quality of life. The Western development process has destroyed wholesome and sustainable lifestyles. In India, the Green Revolution caused many small farmers to lose their land. In comparison to traditional economies, industrial economies have longer technological chains dependent on higher energy and resource inputs and exclude large numbers of people without power to buy goods. Further, they generate new and artificial needs, necessitating increased production of industrial goods and services. They erode resource bases for survival. This erosion is marginalizing people who were traditionally in nature's economy. Developed countries did not deliver 0.15% of their GNP to development projects in developing countries as promised. The US made population growth in these countries its cause. The UN and other multinational agencies during 1962-1972, at the US's request, began to support population and family planning programs in developing countries. These countries opposed the 1st draft at the 1974 Bucharest Population Conference, but by the conference in Mexico City, most supported the need for family planning. Yet, the US politicized this conference and had a greater say in the recommendations than did developing countries. Structural adjustments and external debt repayments required of developing countries in the 1980s set them back. In fact, the number of developing countries increased from 31 to 42. The UN recognizes the right to development, but social inequalities are barriers to this right. If environmental degradation continues, poverty will only increase. Women's groups are playing a great role in preparations for the International Conference on Population and Development in Cairo in September 1994. PMID:12345781

  1. Population dynamics and interactions

    Pimentel, Carla Sofia Madeira Gomes

    2004-01-01

    In the present work, we studied a common outbreaking Lepidoptera species in Portuguese pine stands – Thaumetopoea pityocampa (Den. & Schiff.) - and one of its potential predators – Parus major (L.). The population dynamics of the immature stages of the Lepidoptera was studied in several types of Pinus pinaster (Aiton) plantations in three different areas: Setúbal Peninsula, Abrantes and National Pine Forest of Leiria. Location and plantation structure was the most important factors determinin...

  2. Population, desertification, and migration.

    Westing, A H

    1994-01-01

    When an imbalance develops between population numbers and the carrying capacity of the land, the persons thereby displaced are referred to as environmental refugees. The utilization of the land beyond sustainability leads to land degradation and ultimately, desertification. The social and political impacts of long-term environmental migration can be distinguished: a) at the site of origin of the displaced persons by the residual population; b) at rural sites of destination within the nation between the new arrivals and preestablished populations; c) in the cities within the nation; d) in the nonindustrialized foreign countries; and e) in the industrialized foreign countries. In the event that an area which had previously been devoted to pastoralism is converted to agriculture, the displaced pastoralists might respond through armed rebellion. In some instances, the disenchanted urban squatters become a politically restive and even a destabilizing force, as occurred in Sudan in the 1980s, especially in Khartoum and Port Sudan. The foreign countries to which many of the displaced persons are migrating are subjected to increasing levels of migrant-induced economic, cultural, and political strains. The growing problems associated with south-to-north migration across the Mediterranean Sea have recently led France, Italy, Portugal, and Spain to enter into a consultative arrangement with Algeria, Libya, Mauritania, Morocco, and Tunisia. All foreign aid to the nonindustrialized countries that attempts to ameliorate the problem of desertification must adopt integrated approaches that: a) address population issues; b) support environmental education; c) provide for the protection of biodiversity; d) encourage participatory forms of local and national government; e) provide opportunities for income generation outside the livestock sector; and f) foster political security and facilitate ecogeographical (subregional) cooperation. PMID:12289925

  3. Target population growth: zero.

    2000-02-01

    The Fifth Session of the Fourth National Council of the China Family Planning Association held in Beijing on December 13, 1999, focused on how to control the number of people in China and improve their quality of life. Family planners also explored ways to decrease the number of babies with birth defects and maternal mortality rate. During the meeting, Zhang Weiqing, minister of the State Family Planning Commission, expressed that they are optimistic about keeping the Chinese population under 1.3 billion before the 21st century. He added that top attention should be paid to providing family planning service (sexual and reproductive counseling) for unmarried young people, laid-off workers, and the transient population in urban areas. In Shenzhen, a special economic zone, 854 family planning offices have been established among 2.8 million temporary residents, these agencies, many of which are led by temporary residents themselves. Lastly, Zhang announced that a draft national law on population and family planning has been finished and the law is expected to be enacted in 3 years. PMID:12295907

  4. Genetic changeover in Drosophila populations

    Three populations of Drosophila melanogaster that were daughter populations of two others with histories of high, continuous radiation exposure [population 5 (irradiated, small population size) gave rise to populations 17 (small) and 18 (large); population 6 (irradiated, large population size) gave rise to population 19 (large)] were maintained for 1 year with no radiation exposure. The frequency with which random combinations of second chromosomes taken from population 19 proved to be lethal changed abruptly after about 8 months, thus revealing the origin of a selectively favored element in that population. (This element may or may not have been the cause of the lethality.) A comparison of the loss of lethals in populations 17 and 18 with a loss that occurred concurrently in the still-irradiated population 5 suggests that a second, selectively favored element had arisen in that population just before populations 17 and 18 were split off. This element was on a nonlethal chromosome. The result in population 5 was the elimination of many lethals from that population, followed by a subsequent increase as mutations occurred in the favored nonlethal chromosome. Populations 17 and 18, with no radiation exposure, underwent a loss of lethals with no subsequent increase. The events described here, as well as others to be described elsewhere, suggest that populations may be subject to episodic periods of rapid gene frequency changes that occur under intense selection pressure. In the instances in which the changeover was revealed by the elimination of preexisting lethals, earlier lethal frequencies were reduced by approximately one-half; the selectively favored elements appear, then, to be favored in the heterozygous--not homozygous--condition

  5. Population policies and development.

    Stamper, B M

    1984-01-01

    This article critically examines 4 conceptual frameworks for Third World population policies: the family planning approach, beyond family planning measures, the development hypothesis and transition theory, and the distributive hypothesis and fertility. Although family planning is a basic human right and can lead to lower levels of population and improved maternal-child health, this approach alone does not always have a meaningful demographic impact. If high fertility is economically rational from the family viewpoint, the demand for family planning services will remain marginal. Other policies seek to go beyond the family planning approach and to directly influence the demand for reproductive control through provision of old age support, monetary incentives for reduced fertility or stringent and coercive measures. However, such policies can have adverse distributional effects and directly penalize the children of large families. The demographic transition theory lacks a measurable and specifiable causation mechanism, giving it little predictive value. It may be that economic growth increases fertility in the short run and reduces fertility only over the long run through indirect effects. The key issue is how the rate of growth is distributed across the population. The development and demographic transition hypothesis focuses mainly on aggregate economic and social measures rather than on their underlying distributions. The distributive hypothesis implies policies that promote a greater level of investment in human capital, with a wide distributional emphasis. Diffused investment in human capital is believed to indirectly influence the desire to control fertility. It is concluded that all 4 conceptual frameworks for analyzing fertility-related policies for the Third World are inadequate or seriously flawed. They are not pragmatic, do not identify or assign weights to the crucial causal variables, fail to specify thresholds or critical minimum levels, discount cultural settings, and ignore the manipulability of key variables. PMID:12266706

  6. The aging population in Brazil

    Fabio Nasri

    2008-03-01

    Full Text Available Brazil is currently in an advanced stage of both the mortality andfertility transitions, which allows one to confi dently forecast the agedistribution and population size over the next four decades. Whereasthe elderly population with more than 65 years will increase at highrates (2 to 4% per year the young population will decline. Accordingto United Nations projections, the elderly population will increasefrom 3.1% of the population in 1970 to 19% in 2050. The changingage distribution of the Brazilian population brings opportunities andchallenges that could lead to serious social and economic issues ifnot dealt with properly in coming decades.

  7. Diabetes in Population Isolates

    Grarup, Niels; Moltke, Ida; Albrechtsen, Anders; Hansen, Torben

    Type 2 diabetes (T2D) is an increasing health problem worldwide with particularly high occurrence in specific subpopulations and ancestry groups. The high prevalence of T2D is caused both by changes in lifestyle and genetic predisposition. A large number of studies have sought to identify the...... glucose-stimulated plasma glucose, serum insulin levels, and T2D. The variant defines a specific subtype of non-autoimmune diabetes characterized by decreased post-prandial glucose uptake and muscular insulin resistance. These and other recent findings in population isolates illustrate the value of...

  8. Surgery and refugee populations.

    Kushner, A L; Groen, R S; Kingham, T P

    2009-01-01

    Although infectious diseases, malnutrition and diarrhea account for the vast majority of deaths in many crisis situations, many individuals also suffer from traumatic injuries and other surgically treatable conditions. Understanding the determinants involved in surgical interventions is facilitated by defining baseline, emergent and chronic phases for refugees and internally displaced populations. International aid organizations often expend vast resources on surgical interventions. More detailed assessments and further study may help provide insight into optimizing the success and minimizing the cost of such interventions. This article is a review of the surgical and disaster literature and defines issues for further study. PMID:19447737

  9. Neoplasms in irradiated populations

    The paper describes the results of three prospective studies which have been ongoing for 25 years. The study populations include: (1) persons treated with x rays in infancy for alleged enlargement of the thymus gland; (2) persons treated in childhood with x rays and/or radium for lymphoid hyperplasia of the nasopharynx; and (3) women treated with x rays for acute postpartum mastitis. The studies have resulted in the quantification of risk for radiogenic thyroid and breast cancer for periods up to 40 years post irradiation

  10. Playing With Population Protocols

    Xavier Koegler

    2009-06-01

    Full Text Available Population protocols have been introduced as a model of sensor networks consisting of very limited mobile agents with no control over their own movement: A collection of anonymous agents, modeled by finite automata, interact in pairs according to some rules. Predicates on the initial configurations that can be computed by such protocols have been characterized under several hypotheses. We discuss here whether and when the rules of interactions between agents can be seen as a game from game theory. We do so by discussing several basic protocols.

  11. India's population in transition.

    Visaria, L; Visaria, P

    1995-10-01

    This demographic profile of India addresses fertility, family planning, and economic issues. India is described as a country shifting from economic policies of self-reliance to active involvement in international trade. Wealth has increased, particularly at higher educational levels, yet 25% still live below the official poverty line and almost 66% of Indian women are illiterate. The government program in family planning, which was instituted during the early 1950s, did not change the rate of natural increase, which remained stable at 2.2% over the past 30 years. 1993 marked the first time the growth rate decline to under 2%. The growth rate in 1995 was 1.9%. The total population is expected double in 36 years. Only Nigeria, Pakistan, and Bangladesh had a higher growth rate and higher fertility in 1995. India is geographically diverse (with the northern Himalayan mountain zone, the central alluvial plains, the western desert region, and the southern peninsula with forest, mountains, and plains). There are regional differences in the fertility rates, which range from replacement level in Kerala and Goa to 5.5 children in Uttar Pradesh. Fertility is expected to decline throughout India due to the slower pace of childbearing among women over the age of 35 years, the increase in contraceptive use, and increases in marriage age. Increased educational levels in India and its state variations are related to lower fertility. Literacy campaigns are considered to be effective means of increasing the educational levels of women. Urbanization is not expected to markedly affect fertility levels. Urban population, which is concentrated in a few large cities, remains a small proportion of total population. Greater shifts are evident in the transition from agriculture to other wage labor. Fertility is expected to decline as women's share of labor force activity increases. The major determinant of fertility decline in India is use of family planning, which has improved in access and use during the 1980s. If India is to keep a stable population under 1.6 billion in the future, Indians may have to accept only one child per family. PMID:12290691

  12. Density Estimation in Several Populations With Uncertain Population Membership

    Ma, Yanyuan

    2011-09-01

    We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.

  13. Population Trends and the Status of Population Policy in Africa.

    Rogge, John R.

    1982-01-01

    The major trend towards worldwide easing of the birthrate does not include the current population patterns in Africa. The population policies of African nations range along a continuum from totally pronatal to strongly antinatal. However, even antinatal policies have had little effect on the overall spiralling upward population trend. (JA)

  14. Population dose estimation

    Critical organs in the individual or group injury due to radiation exposure are gonad and bone marrow. Estimation of the injury is performed with gonad dose and bone marrow dose, respectively. It is performed with genetically significant dose and leukaemia significant dose for groups. Estimation of the dose absorbed into the critical organs and population dose (significant) is described, but in limited case of photons. Tissue equivalent phantom must be utilized to determine the absorbed dose of critical organs. Absorbed dose distribution in human body is more complex because environmental radiation is not parallel beam, but impinges from 4? directions, and its flux is directional. Simple explanation on both gonad dose and bone marrow dose is conducted. In estimating population dose, it is necessary to multiply the weight based on individual condition. The dose determined in accordance with the above concept is significant dose. Genetically significant and leukaemia significant doses are defined. Though the United Nations Scientific Committee employs average bone marrow dose per year per man instead of the leukaemia significant dose, the Committee will transfer to use the significant dose corrected with weighting factor in future. (Wakatsuki, Y.)

  15. POPULATION III HYPERNOVAE

    Population III supernovae have been of growing interest of late for their potential to directly probe the properties of the first stars, particularly the most energetic events that are visible near the edge of the observable universe. Until now, hypernovae, the unusually energetic Type Ib/c supernovae that are sometimes associated with gamma-ray bursts, have been overlooked as cosmic beacons at the highest redshifts. In this, the latest of a series of studies on Population III supernovae, we present numerical simulations of 25-50 M ? hypernovae and their light curves done with the Los Alamos RAGE and SPECTRUM codes. We find that they will be visible at z = 10-15 to the James Webb Space Telescope and z = 4-5 to the Wide-Field Infrared Survey Telescope, tracing star formation rates in the first galaxies and at the end of cosmological reionization. If, however, the hypernova crashes into a dense shell ejected by its progenitor, it is expected that a superluminous event will occur that may be seen at z ? 20 in the first generation of stars

  16. POPULATION III HYPERNOVAE

    Smidt, Joseph; Whalen, Daniel J. [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Wiggins, Brandon K. [Department of Physics and Astronomy, Brigham Young University, Provo, UT 84602 (United States); Even, Wesley; Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Johnson, Jarrett L., E-mail: dwhalen1999@gmail.com [XTD-PRI, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-12-20

    Population III supernovae have been of growing interest of late for their potential to directly probe the properties of the first stars, particularly the most energetic events that are visible near the edge of the observable universe. Until now, hypernovae, the unusually energetic Type Ib/c supernovae that are sometimes associated with gamma-ray bursts, have been overlooked as cosmic beacons at the highest redshifts. In this, the latest of a series of studies on Population III supernovae, we present numerical simulations of 25-50 M {sub ☉} hypernovae and their light curves done with the Los Alamos RAGE and SPECTRUM codes. We find that they will be visible at z = 10-15 to the James Webb Space Telescope and z = 4-5 to the Wide-Field Infrared Survey Telescope, tracing star formation rates in the first galaxies and at the end of cosmological reionization. If, however, the hypernova crashes into a dense shell ejected by its progenitor, it is expected that a superluminous event will occur that may be seen at z ∼ 20 in the first generation of stars.

  17. In vitro Survival and Nematicidal Activity of Rhizobium, Bradyrhizobium and Sinorhizobium. I. The Influence of Various NaCl Concentrations

    S. Shahid Shaukat

    2002-01-01

    Full Text Available During the survey of the cultivated fields in Karachi and neighborhood (Southern Sindh, 3 strains of Rhizobium phaseoli, 1 strain of R. leguminosarum and R. trifolii each, 5 strains of Sinorhizobium meliloti, 2 strains of Bradyrhizobium japonicum and 3 strains of Bradyrhizobium sp. were isolated and identified. The 15 strains of rhizobia tested for their growth under saline media exhibited varying degree of effects to salt concentrations. Most resistant strain was that of S. meliloti MAT1(R9 while least resistant was that of Bradyrhizobium sp. VRM1(R13. All the rhizobial strains caused significant mortality of Meloidogyne incognita, the root-knot nematode juveniles in vitro, though the strains differed markedly in their toxic activity. The rhizobial strains showed significant interaction with NaCl salinity towards M. incognita

  18. Potential of foliar, dip, and injection applications of avermectins for control of plant-parasitic nematodes.

    Jansson, R K; Rabatin, S

    1998-03-01

    Studies were conducted to determine the potential of two avermectin compounds, abamectin and emamectin benzoate, for controlling plant-parasitic nematodes when applied by three methods: foliar spray, root dip, and pseudostem injection. Experiments were conducted against Meloidogyne incognita on tomato, M. javanica on banana, and Radopholus similis on banana. Foliar applications of both avermectins to banana and tomato were not effective for controlling any of the nematodes evaluated. Root dips of banana and tomato were moderately effective for controlling M. incognita on tomato and R. similis on banana. Injections (1 ml) of avermectins into banana pseudostems were effective for controlling M. javanica and R similis, and were comparable to control achieved with a conventional chemical nematicide, fenamiphos. Injections of 125 to 2,000 mug/plant effectively controlled one or both nematodes on banana; abamectin was more effective than emamectin benzoate for controlling nematodes. PMID:19274200

  19. Millennium Ecosystem Assessment: MA Population

    National Aeronautics and Space Administration The Millennium Ecosystem Assessment: MA Population data sets provide baseline population information as one of the drivers of ecosystem change. The data helped in...

  20. Millennium Ecosystem Assessment: MA Population

    National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Population data sets provide baseline population information as one of the drivers of ecosystem change. The data helped in...