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

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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.

E. Mahdikhani Moghadam; A. kheiri; M. Mohammadi

2007-01-01

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Relationship Between Morphology and Parasitism in Two Populations of Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

The reliability of morphological characters and host differential plants for distinguishing between two populations of Meloidogyne incognita was studied. Population A (originally from North Carolina) had incognita-type perineal patterns. A single egg mass subpopulation of population A had a mixture of incognita and acrita perineal patterns with 33% of the patterns atypical for either species. Population B (from Georgia) had predominantly acrita-type patterns with only about 5% atypical patterns. The head shapes of males from both populations were mainly M. incognita. On the basis of stylet length, both populations conformed to M. incognita acrita. Both populations were identified as M. incognita race 1 by reaction on the North Carolina differential hosts. Reactions on azalea and pepper gave no clear identification of the populations. We concluded that there is no relation between perineal pattern, male head shape, and parasitism of host differentials with the two populations studied.

Canto-Saénz M; Brodie BB

1987-01-01

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Effects of cultivars, subsoiling, and fumigation on soybean yields and Meloidogyne incognita populations.  

UK PubMed Central (United Kingdom)

Application of 1,2-dibromo-3-chloropropane (DBCP) and subsoiling under the row in Tifton sandy loam heavily infested with Meloidogyne incognita increased yields of four soybean cultivars. These cultivars have levels of resistance to M. incognita as follows: 'Hutton', high; 'Essex', intermediate; and 'Davis' and 'Ransom', low. After growing these four cultivars, sub-soiling, and applying DBCP for 2 years in the same plots, the residual effects of these practices on yield of Davis cultivar and populations of M. incognita were studied. Greatest yields of Davis were obtained on plots previously planted to Hunon and Essex and on plots previously treated with DBCP for 2 years. Residual effects of subsoiling on yield were not significant. Data on nematode populations indicated that some residual effects occurred because of cultivars and nematicides. However, root-knot was suppressed only where DBCP was applied the 2 previous years. Although beneficial residual effects occurred, they were not sufficient for maximum soybean production.

Minton NA; Parker MB; Mullinix BG

1978-01-01

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INTERACCIÓN ENTRE EL ECOMIC® Y UNA POBLACIÓN CUBANA DE Meloidogyne incognita EN TOMATE/ INTERACTION BETWEEN ECOMIC® AND A CUBAN POPULATION OF Meloidogyne incognita IN TOMATO  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El estudio de tácticas para el manejo de los nematodos agalleros en la producción protegida de hortalizas en Cuba, se ha incrementado en los últimos años. El objetivo del trabajo fue determinar la interacción entre el ECOMICâ, producto a base de hongos formadores de micorrizas arbusculares, y una población cubana de Meloidogyne incognita en el tomate (Lycopersicon esculentum. Mill var. Vyta). El experimento se desarrolló en los aisladores biológicos del CENSA emp (more) leando un diseño completamente aleatorio. Se emplearon dos formas de inoculación del ECOMICâ: peletización de la semilla e incorporación al sustrato para semilleros (1.5 g del producto/alveolo de cepellón). La dosis de nematodos fue de 1.5 huevos-J2. g suelo-1. Se evaluó el índice de agallamiento (IA), el número de juveniles infectivos (J2) en suelo y peso del sistema radical. La evaluación de la simbiosis micorrícica comprendió el porcentaje de colonización, densidad visual y peso del endófito. Se demostró que la aplicación de ECOMICâen la rizosfera del tomate favoreció el desarrollo de la raíz aparejado con un alto número de agallas (IA=4). En el control el desarrollo de la raíz fue menor con un IA=5. Se observó una disminución de los J2 en el suelo de las plantas micorrizadas. El establecimiento de la simbiosis micorrícica no se afectó por el desarrollo del nematodo. Abstract in english The study of tactics for the root-knot nematode management in vegetable production under crop protected systems has been increased in Cuba in the last decade. The main goal of this work was to assess the relationship of ECOMIC®, a commercial product containing several mycorrhizal fungi, and a Cuban population of Meloidogyne incognita in tomato (Lycopersicon esculentum Mill var. Vyta). The experiment was carried out in a green house at CENSA using a completely randomized (more) design. ECOMICâ was inoculated by seed pelleting or mixed with the seedbed substrate. The nematode dose used was 1.5 egg-J2. g soil-1. Gall index, infective juveniles in soil and root weight were evaluated. The percentage of colonization, the visual density and the mycellial weight were also estimated. ECOMICâ was shown to benefit root development despite the high value of the gall index (GI=4) in the inoculated plants. Root development was lower in the untreated plants with a GI=5. A decreased number of infective juveniles was observed in the soil with mycorrhized plants. The micorrhizal colonization was not affected by nematode establishment.

Gómez, Lucila; Rodríguez, MayraG; de la Noval, Blanca; Ileana, Miranda; Hernández, M.A

2008-08-01

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Surface Coat of Meloidogyne incognita.  

Science.gov (United States)

The nematode surface coat is defined as an extracuticular component on the outermost layer of the nematode body wall, visualized only by electron microscopy. Surface coat proteins of Meloidogyne incognita race 3 infective juveniles were characterized by electrophoresis and Western blotting of extracts from radioiodine and biotin-labeled nematodes. Extraction of labeled nematodes with cetyltrimethylammonium bromide yielded a principal protein band larger than 250 kDa and, with water soluble biotin, several faint bands ranging from 31 kDa to 179 kDa. The pattern of labeling was similar for both labeling methods. Western blots of unlabeled proteins were probed with a panel of biotin-lectin conjugates, but only Concanavalin A bound to the principal band. Nematodes labeled with radioiodine and biotin released (1)(2)I and biotin-labeled molecules into water after 20 hours incubation, indicating that surface coat proteins may be loosely attached to the nematode. Antiserum to the partially purified principal protein bound to the surface of live nematodes and to several proteins on Western blots. Differential patterns of antibody labeling were obtained on immuno-blots of extracts from M. incognita race 1, 2, and 3; Meloidogyne hapla race 2; and Meloidogyne arenaria cytological race B. PMID:19277137

Lin, H J; McClure, M A

1996-06-01

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

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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 ...

Meyer, S.L.F.

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Characterization of Meloidogyne incognita populations from São Paulo and Minas Gerais state and their pathogenicity on coffee plants Caracterização de populações de Meloidogyne incognita de São Paulo e Minas Gerais e sua patogenicidade em cafeeiro  

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Full Text Available Meloidogyne incognita is one of the most aggressive and harmful plant-parasitic nematodes attacking coffee plantations in Brazil. However, populations from Minas Gerais state (MG) do not incite disease on coffee plants as strongly as populations from São Paulo state (SP). This study aimed to compare the capacity to incite disease on coffee plants from SP and MG-populations based on penetration and post-infective development of second-stage juveniles (J2) stage. Both populations were confirmed as M. incognita by using esterase phenotype I1 and species-specific PCR. Physiologically they were classified as race 2 by differential host test. Susceptible (C. arabica 'Catuaí Vermelho IAC 44') and resistant coffee seedlings (C. canephora 'Apoatã IAC 2258') were inoculated with J2 and assessed for penetration and development from 2nd to 40th day after inoculation. Although the penetration rate of the J2 from both populations was higher in susceptible than in resistant seedlings, the SP-population showed a higher penetration than the MG-population for both variables. Post-infective development proceeded only in individuals of the SP-population in susceptible seedlings. The incompatibility between the MG-population and coffee seedlings was evident at the penetration phase, which was also followed by post-penetration resistance factors leading to significant J2 emigration, impeding nematode establishment.No Brasil, Meloidogyne incognita é considerado um dos fitonematóides mais agressivos e prejudiciais ao cafeeiro. Entretanto, populações desse nematóide, presentes em Minas Gerais, são incapazes de infectar esse hospedeiro. O objetivo deste trabalho foi caracterizar e avaliar a penetração e o desenvolvimento pós-infectivo de populações de M. incognita que diferem quanto à capacidade de infectar o cafeeiro. As duas populações foram confirmadas como M. incognita pelo fenótipo isoenzimático de esterase, I1, e PCR específico. Foram classificadas como raça 2 pela reação dos hospedeiros diferenciadores. Mudas de cafeeiro suscetível e resistente foram inoculadas com juvenis de segundo estádio (J2) de cada população e avaliadas quanto à penetração e desenvolvimento do nematóide a partir do segundo até o quadragésimo dia após a inoculação. A penetração de J2 da população de M. incognita de São Paulo foi maior do que a da população de Minas Gerais, tanto em cafeeiro suscetível (C. arabica 'Catuaí Vermelho IAC 44') quanto resistente (C. canephora 'Apoatã IAC 2258'). Como esperado, ocorreu maior penetração de J2 das duas populações de M. incognita no cafeeiro suscetível. Nas avaliações posteriores, somente foi observado desenvolvimento pós-infectivo nos indivíduos pertencentes à população de M. incognita de São Paulo em cafeeiro suscetível. Os mecanismos que conferiram incompatibilidade entre as populações de M. incognita de Minas Gerais e o cafeeiro atuaram principalmente na fase de penetração, mas também foi acompanhada pela ação de fatores de resistência pós-penetração que ocasionaram uma significativa emigração de J2 e impediram o estabelecimento do nematóide.

Dagoberto S. Oliveira; Rosângela D'Arc Lima Oliveira; Débora G. Silva; Rodrigo V. Silva

2011-01-01

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Characterization of Meloidogyne incognita populations from São Paulo and Minas Gerais state and their pathogenicity on coffee plants/ Caracterização de populações de Meloidogyne incognita de São Paulo e Minas Gerais e sua patogenicidade em cafeeiro  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese No Brasil, Meloidogyne incognita é considerado um dos fitonematóides mais agressivos e prejudiciais ao cafeeiro. Entretanto, populações desse nematóide, presentes em Minas Gerais, são incapazes de infectar esse hospedeiro. O objetivo deste trabalho foi caracterizar e avaliar a penetração e o desenvolvimento pós-infectivo de populações de M. incognita que diferem quanto à capacidade de infectar o cafeeiro. As duas populações foram confirmadas como M. incognit (more) a pelo fenótipo isoenzimático de esterase, I1, e PCR específico. Foram classificadas como raça 2 pela reação dos hospedeiros diferenciadores. Mudas de cafeeiro suscetível e resistente foram inoculadas com juvenis de segundo estádio (J2) de cada população e avaliadas quanto à penetração e desenvolvimento do nematóide a partir do segundo até o quadragésimo dia após a inoculação. A penetração de J2 da população de M. incognita de São Paulo foi maior do que a da população de Minas Gerais, tanto em cafeeiro suscetível (C. arabica 'Catuaí Vermelho IAC 44') quanto resistente (C. canephora 'Apoatã IAC 2258'). Como esperado, ocorreu maior penetração de J2 das duas populações de M. incognita no cafeeiro suscetível. Nas avaliações posteriores, somente foi observado desenvolvimento pós-infectivo nos indivíduos pertencentes à população de M. incognita de São Paulo em cafeeiro suscetível. Os mecanismos que conferiram incompatibilidade entre as populações de M. incognita de Minas Gerais e o cafeeiro atuaram principalmente na fase de penetração, mas também foi acompanhada pela ação de fatores de resistência pós-penetração que ocasionaram uma significativa emigração de J2 e impediram o estabelecimento do nematóide. Abstract in english Meloidogyne incognita is one of the most aggressive and harmful plant-parasitic nematodes attacking coffee plantations in Brazil. However, populations from Minas Gerais state (MG) do not incite disease on coffee plants as strongly as populations from São Paulo state (SP). This study aimed to compare the capacity to incite disease on coffee plants from SP and MG-populations based on penetration and post-infective development of second-stage juveniles (J2) stage. Both popu (more) lations were confirmed as M. incognita by using esterase phenotype I1 and species-specific PCR. Physiologically they were classified as race 2 by differential host test. Susceptible (C. arabica 'Catuaí Vermelho IAC 44') and resistant coffee seedlings (C. canephora 'Apoatã IAC 2258') were inoculated with J2 and assessed for penetration and development from 2nd to 40th day after inoculation. Although the penetration rate of the J2 from both populations was higher in susceptible than in resistant seedlings, the SP-population showed a higher penetration than the MG-population for both variables. Post-infective development proceeded only in individuals of the SP-population in susceptible seedlings. The incompatibility between the MG-population and coffee seedlings was evident at the penetration phase, which was also followed by post-penetration resistance factors leading to significant J2 emigration, impeding nematode establishment.

Oliveira, Dagoberto S.; Oliveira, Rosângela D'Arc Lima; Silva, Débora G.; Silva, Rodrigo V.

2011-06-01

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

Science.gov (United States)

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...

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REPRODUCTION OF MELOIDOGYNE INCOGNITA ON WINTER COVER CROPS USED IN COTTON PRODUCTION  

Science.gov (United States)

Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter will depend on soil temperature and how good of a host the cover crop is for M. incognita. ...

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Detection and Investigation of Soil Biological Activity against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

Greenhouse experiments with two susceptible hosts of Meloidogyne incognita, a dwarf tomato and wheat, led to the identification of a soil in which the root-knot nematode population was reduced 5- to 16-fold compared to identical but pasteurized soil two months after infestation with 280 M. incognita J2/100 cm(3) soil. This suppressive soil was subjected to various temperature, fumigation and dilution treatments, planted with tomato, and infested with 1,000 eggs of M. incognita/100 cm(3) soil. Eight weeks after nematode infestation, distinct differences in nematode population densities were observed among the soil treatments, suggesting the suppressiveness had a biological nature. A fungal rRNA gene analysis (OFRG) performed on M. incognita egg masses collected at the end of the greenhouse experiments identified 11 fungal phylotypes, several of which exhibited associations with one or more of the nematode population density measurements (egg masses, eggs or J2). The phylotype containing rRNA genes with high sequence identity to Pochonia chlamydosporia exhibited the strongest negative associations. The negative correlation between the densities of the P. chlamydosporia genes and the nematodes was corroborated by an analysis using a P. chlamydosporia-selective qPCR assay.

Bent E; Loffredo A; McKenry MV; Becker JO; Borneman J

2008-06-01

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Detection and Investigation of Soil Biological Activity against Meloidogyne incognita.  

Science.gov (United States)

Greenhouse experiments with two susceptible hosts of Meloidogyne incognita, a dwarf tomato and wheat, led to the identification of a soil in which the root-knot nematode population was reduced 5- to 16-fold compared to identical but pasteurized soil two months after infestation with 280 M. incognita J2/100 cm(3) soil. This suppressive soil was subjected to various temperature, fumigation and dilution treatments, planted with tomato, and infested with 1,000 eggs of M. incognita/100 cm(3) soil. Eight weeks after nematode infestation, distinct differences in nematode population densities were observed among the soil treatments, suggesting the suppressiveness had a biological nature. A fungal rRNA gene analysis (OFRG) performed on M. incognita egg masses collected at the end of the greenhouse experiments identified 11 fungal phylotypes, several of which exhibited associations with one or more of the nematode population density measurements (egg masses, eggs or J2). The phylotype containing rRNA genes with high sequence identity to Pochonia chlamydosporia exhibited the strongest negative associations. The negative correlation between the densities of the P. chlamydosporia genes and the nematodes was corroborated by an analysis using a P. chlamydosporia-selective qPCR assay. PMID:19259527

Bent, E; Loffredo, A; McKenry, M V; Becker, J O; Borneman, J

2008-06-01

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Meloidogyne incognita Resistance Characteristics in Tomato Genotypes Developed for Processing.  

UK PubMed Central (United Kingdom)

Nine resistant processing tomato (Lycopersicon esculentum) cultivars and advanced lines were compared with four susceptible cultivars in 1,3-dichloropropene-fumigated and nontreated plots on Meloidogyne incognita-infested sites over 3 years. Yield of all resistant genotypes grown in nontreated and nematicide-treated plots did not differ and was greater than yield of susceptible genotypes. M. incognita initial soil population densities caused 39.3-56.5% significant (P = 0.05) yield suppressions of susceptible genotypes. Nematode injury to susceptible plants usually caused both fruit soluble solids content and pH to increase significantly (P = 0.05). Only trace nematode reproduction occurred on resistant genotypes in nontreated plots, whereas large population density increases occurred on susceptible genotypes. Slightly greater nematode reproduction occurred on resistant genotypes at the southern desert location, where soil temperature exceeded 30 C, than at other locations. At two locations resistant MOX 3076 supported greater reproduction than other resistant genotypes.

Roberts PA; May D

1986-07-01

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Meloidogyne incognita Resistance Characteristics in Tomato Genotypes Developed for Processing.  

Science.gov (United States)

Nine resistant processing tomato (Lycopersicon esculentum) cultivars and advanced lines were compared with four susceptible cultivars in 1,3-dichloropropene-fumigated and nontreated plots on Meloidogyne incognita-infested sites over 3 years. Yield of all resistant genotypes grown in nontreated and nematicide-treated plots did not differ and was greater than yield of susceptible genotypes. M. incognita initial soil population densities caused 39.3-56.5% significant (P = 0.05) yield suppressions of susceptible genotypes. Nematode injury to susceptible plants usually caused both fruit soluble solids content and pH to increase significantly (P = 0.05). Only trace nematode reproduction occurred on resistant genotypes in nontreated plots, whereas large population density increases occurred on susceptible genotypes. Slightly greater nematode reproduction occurred on resistant genotypes at the southern desert location, where soil temperature exceeded 30 C, than at other locations. At two locations resistant MOX 3076 supported greater reproduction than other resistant genotypes. PMID:19294190

Roberts, P A; May, D

1986-07-01

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Influence of 1,3-Dichloropropene, Fenamiphos, and Carbofuran on Meloidogyne incognita Populations and Yield of Chile Peppers  

Science.gov (United States)

Field trials were conducted during 1986, 1988, 1989, and 1991 to compare the effects of 1,3-dichloropropene, fenamiphos, and carbofuran on yield and quality of chile peppers (Capsicum annuum) in soil infested with Meloidogyne incognita. When compared with untreated plots, numbers of M. incognita juveniles recovered from soil 60 and(or) 90 days after chile pepper emergence were reduced (P = 0.05) following 1,3-D treatment every year except 1986. Nematode numbers were also reduced (P = 0.05) by fenamiphos in 1989. Chile pepper yields were significantly higher than those in untreated control plots (P = 0.05) all 4 years in plots treated with 1,3-D and in 1989 in plots treated with fenamiphos. Use of carbofuran did not significantly reduce nematode numbers or enhance yields in these experiments. Green chile pepper fruit quality was enhanced (P = 0.05) following 1,3-D treatments in 1988 and 1989 but was unaffected by fenamiphos or carbofuran application. Increasing placement depth of 1,3-D from 28 to 48 cm increased (P = 0.05) red chile pepper yield compared with that obtained with conventional placement in 1988 only, and did not affect green chile pepper yield.

Thomas, S. H.

1994-01-01

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Influence of 1,3-Dichloropropene, Fenamiphos, and Carbofuran on Meloidogyne incognita Populations and Yield of Chile Peppers.  

UK PubMed Central (United Kingdom)

Field trials were conducted during 1986, 1988, 1989, and 1991 to compare the effects of 1,3-dichloropropene, fenamiphos, and carbofuran on yield and quality of chile peppers (Capsicum annuum) in soil infested with Meloidogyne incognita. When compared with untreated plots, numbers of M. incognita juveniles recovered from soil 60 and(or) 90 days after chile pepper emergence were reduced (P = 0.05) following 1,3-D treatment every year except 1986. Nematode numbers were also reduced (P = 0.05) by fenamiphos in 1989. Chile pepper yields were significantly higher than those in untreated control plots (P = 0.05) all 4 years in plots treated with 1,3-D and in 1989 in plots treated with fenamiphos. Use of carbofuran did not significantly reduce nematode numbers or enhance yields in these experiments. Green chile pepper fruit quality was enhanced (P = 0.05) following 1,3-D treatments in 1988 and 1989 but was unaffected by fenamiphos or carbofuran application. Increasing placement depth of 1,3-D from 28 to 48 cm increased (P = 0.05) red chile pepper yield compared with that obtained with conventional placement in 1988 only, and did not affect green chile pepper yield.

Thomas SH

1994-12-01

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

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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.

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

1996-01-01

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Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production  

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Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to qua...

Timper, Patricia; Davis, Richard F.; Tillman, P. Glynn

19

Damage Potential and Reproduction of Meloidogyne incognita Race 3 and M. arenaria Race 1 on Kenaf  

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The effects of Meloidogyne incognita race 3 and M. arenaria race 1 on growth of kenaf cv. Everglades 41 was determined under greenhouse conditions. Seedlings of kenaf were inoculated with initial population densities (Pi) of 0, 625, 1,250, 2,500, 5,000, and 10,000 eggs/plant and placed on greenhouse...

Zhang, F.; Noe, J. P.

20

PLANT-DERIVED COMPOUNDS ACTIVE AGAINST MELOIDOGYNE INCOGNITA  

Science.gov (United States)

Products from two plant genera, Plantago and Eugenia, were tested for effects on the root-knot nematode Meloidogyne incognita. Extracts from P. lanceolata and P. rugelii were also evaluated for toxicity to the plant-pathogenic fungi Fusarium oxysporum f. sp. gladioli, Phytophthora capsici, Pythium ...

 
 
 
 
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Population Dynamics of Meloidogyne incognita, M. arenaria,and Other Nematodes and Crop Yields in Rotations of Cotton, Peanut, and Wheat Under Minimum Tillage.  

UK PubMed Central (United Kingdom)

Wheat, cotton, and peanut were arranged in three cropping sequences to determine the effects of fenamiphos (6.7 kg a.i./ha) and cropping sequence on nematode population densities and crop yields under conservation tillage and irrigation for 6 years. The cropping sequences included a wheat winter cover crop each year and summer crops of cotton every year, peanut every year, or cotton rotated every other year with peanut. The population densities of Meloidogyne spp. and Helicotylenchus dihystera were determined monthly during the experiment. Numbers of M. incognita increased on cotton and decreased on peanut, whereas M. arenaria increased on peanut, and decreased on cotton; both nematode species remained in moderate to high numbers in plots of wheat. Root damage was more severe on cotton than peanut and was not affected by fenamiphos treatment. The H. dihystera population densities were highest in plots with cotton every summer, intermediate in the cotton-peanut rotation, and lowest in plots with peanut every summer. Over all years and cropping sequences, yield increases in fenamiphos treatment over untreated control were 9% for wheat, 8% for cotton, and 0% for peanut. Peanut yields following cotton were generally higher than yields following peanut. These results show that nematode problems may be manageable in cotton and peanut production under conservation tillage and irrigation in the southeastern United States.

Johnson AW; Dowler CC; Handoo ZA

2000-03-01

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Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production.  

Science.gov (United States)

Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover crops and to determine if these cover crops increase population densities of M. incognita and subsequent damage to cotton. The cover crops tested were 'Bigbee' berseem clover (Trifolium alexandrinum), 'Paradana' balansa clover (T. balansae), 'AU Sunrise' and 'Dixie' crimson clover (T. incarnatum), 'Cherokee' red clover (T. pratense), common and 'AU Early Cover' hairy vetch (Vicia villosa), 'Cahaba White' vetch (V. sativa), and 'Wrens Abruzzi' rye. In the greenhouse tests, egg production was greatest on berseem clover, Dixie crimson clover, AU Early Cover hairy vetch, and common hairy vetch; intermediate on Balansa clover and AU Sunrise crimson clover; and least on rye, Cahaba White vetch, and Cherokee red clover. In both 2002 and 2003 field tests, enough heat units were accumulated between 1 January and 20 May for the nematode to complete two generations. Both AU Early Cover and common hairy vetch led to greater root galling than fallow in the subsequent cotton crop; they also supported high reproduction of M. incognita in the greenhouse. Rye and Cahaba White vetch did not increase root galling on cotton and were relatively poor hosts for M. incognita. Only those legumes that increased populations of M. incognita reduced cotton yield. In the southern US, M. incognita can complete one to two generations on a susceptible winter cover crop, so cover crops that support high nematode reproduction may lead to damage and yield losses in the following cotton crop. Planting rye or Meloidogyne-resistant legumes as winter cover crops will lower the risk of increased nematode populations compared to most vetches and clovers. PMID:19259434

Timper, Patricia; Davis, Richard F; Tillman, P Glynn

2006-03-01

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Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production.  

UK PubMed Central (United Kingdom)

Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover crops and to determine if these cover crops increase population densities of M. incognita and subsequent damage to cotton. The cover crops tested were 'Bigbee' berseem clover (Trifolium alexandrinum), 'Paradana' balansa clover (T. balansae), 'AU Sunrise' and 'Dixie' crimson clover (T. incarnatum), 'Cherokee' red clover (T. pratense), common and 'AU Early Cover' hairy vetch (Vicia villosa), 'Cahaba White' vetch (V. sativa), and 'Wrens Abruzzi' rye. In the greenhouse tests, egg production was greatest on berseem clover, Dixie crimson clover, AU Early Cover hairy vetch, and common hairy vetch; intermediate on Balansa clover and AU Sunrise crimson clover; and least on rye, Cahaba White vetch, and Cherokee red clover. In both 2002 and 2003 field tests, enough heat units were accumulated between 1 January and 20 May for the nematode to complete two generations. Both AU Early Cover and common hairy vetch led to greater root galling than fallow in the subsequent cotton crop; they also supported high reproduction of M. incognita in the greenhouse. Rye and Cahaba White vetch did not increase root galling on cotton and were relatively poor hosts for M. incognita. Only those legumes that increased populations of M. incognita reduced cotton yield. In the southern US, M. incognita can complete one to two generations on a susceptible winter cover crop, so cover crops that support high nematode reproduction may lead to damage and yield losses in the following cotton crop. Planting rye or Meloidogyne-resistant legumes as winter cover crops will lower the risk of increased nematode populations compared to most vetches and clovers.

Timper P; Davis RF; Tillman PG

2006-03-01

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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  

Directory of Open Access Journals (Sweden)

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 nematóide. 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.

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

1996-01-01

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Virulence of Meloidogyne incognita to expression of N gene in pepper.  

UK PubMed Central (United Kingdom)

Four pepper genotypes classified as resistant and four pepper genotypes classified as susceptible to several avirulent populations of M. incognita were compared for their reactions against a population of Meloidogyne incognita (Chitwood) Kofoid and White which had been shown to be virulent to resistant bell pepper (Capsicum annuum) in preliminary tests. The virulent population of M. incognita originated from a commercial bell pepper field in California. The resistant pepper genotypes used in all experiments were the Capsicum annuum cultivars Charleston Belle, Carolina Wonder, and Carolina Cayenne, and the C. chinense cultigen PA-426. The susceptible pepper genotypes used in the experiments were the C. annuum cultivars Keystone Resistant Giant, Yolo Wonder B, California Wonder, and the C. chinense cultigen PA-350. Root gall indices (GI) were ? 3.0 for all genotypes in both tests except for PA-426 (GI=2.57) in test 1 and 'Carolina Cayenne' (GI=2.83) in test 2. Numbers of eggs per gram fresh root weight ranged from 20,635 to 141,319 and reproductive indices ranged from 1.20 to 27.2 for the pepper genotypes in both tests, indicating that all eight pepper genotypes tested were susceptible to the M. incognita population used in these tests. The M. incognita population used in these studies overcame resistance conferred by the N gene in all resistant genotypes of both C. annuum and C. chinense.

Thies JA

2011-06-01

26

Reaction of common bean genotypes to Meloidogyne incognita Race 1 Reação do plantas de feijoeiro a Meloidogyne incognita Raça 1  

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Full Text Available ABSTRACT The objective was to determine the reaction of 33 Phaseolus vulgaris L. genotypes to parasitism by Meloidogyne incognita race 1. The genotypes used in this study six included commercially exploited ("IAPAR­- 81", "EL- 22", "Carioca", "Serrano", "BATT- 477" and "Uirapuru") varieties, one susceptible ("Rico- 23") and two resistant ("Aporé" and "Pérola") varieties; the others were provided by farmers of the South of Espírito Santo State. The experiment was carried out in a greenhouse in a completely randomized design with 7 replicates. The plants were inoculated with 4,000 eggs + second-stage juveniles (J2) of nematodes. After 50 days, the final population of nematodes (FP), reproduction factor (RF) and percentage reproduction rate (%RR) were evaluated. The resistance selection was based on the %RR, i.e., 0-25% = highly susceptible (HS); 26-50% = susceptible (SU); 51-75% = little resistant (LR); 76-95% = moderately resistant (MR); 96-99% = resistant (RE); 100% = highly resistant (HR) or immune (IM). Only the genotype "Preto Meia Lua" was highly resistant. The genotypes "Terrinha- 2" and "Mulatinho" were classified as resistant, "EL- 22", "BATT- 477", "Vermelho", "Bate Estrada" and "Paina" as (susceptible) and genotypes "Rico 23" and "Morgado" as highly susceptible.RESUMO Objetivou-se com esse trabalho estudar a reação de 33 genótipos de Phaseolus vulgaris L. ao parasitismo de Meloidogyne incognita raça 1 em casa de vegetação. Desses genótipos seis são cultivados comercialmente ("IAPAR­- 81" , "EL- 22" , "Carioca", "Serrano", "BATT- 477" e "Uirapuru"), um é suscetível ("Rico- 23" ), dois são resistentes ("Aporé" e "Pérola") e os demais foram resgatados em propriedades localizadas no Sul do Espírito Santo. O experimento foi conduzido em casa de vegetação em delineamento inteiramente casualisado com 7 repetições. As plantas foram inoculadas com 4.000 ovos + juvenis de segundo estádio (J2) do nematóide. Após 50 dias da inoculação, foram avaliados a população final de nematóides (PF), fator de reprodução (FR) e o percentual de redução do fator de reprodução (% RFR). Os genótipos foram classificados como altamente susceptível (AS), susceptível (SU), pouco resistente (PR), moderadamente resistente (MR), resistente (RE), altamente resistente (AR) ou imune (IM). Apenas o genótipo "Preto Meia Lua" comportou-se como AR. Os genótipos "Terrinha- 2" e "Mulatinho" foram classificados como RE, os genótipos "EL- 22", "BATT- 477", "Vermelho", "Bate Estrada" e "Paina" como SU e os genótipos "Rico- 23" e "Morgado" como AS.

Fábio R Alves; Leonardo N. S dos Santos; Willian B Moraes; Fernando C Cosmi; Pablo D. S Cabral; Sebastião Martins Filho; Frederico De Pina Matta; Waldir C. Jesus Júnior

2011-01-01

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

Directory of Open Access Journals (Sweden)

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.

S.L. MACIEL; L.C.C.B. FERRAZ

1996-01-01

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Reação de porta-enxertos de pessegueiro à Meloidogyne incognita/ Reaction of peach rootstocks to Meloidogyne incognita  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo foi avaliar a reação de cinco porta-enxertos de pessegueiro ao Meloidogyne incognita (Kofoid e White) Chitwood, em condições de casa de vegetação. Foram utilizados os porta-enxertos: 'Seleção UFPel 0402', 'Okinawa', 'Nagano Wild', 'Flordaguard' e 'Seleção NR-0080407'. As plantas foram inoculadas com 10.000 ovos+J2 de Meloidogyne incognita. Cinco plantas de tomateiro cv. Santa Cruz foram inoculadas para comprovação da eficiência do inóculo. O delin (more) eamento experimental foi o inteiramente casualizado, com cinco repetições e uma planta por parcela. Seis meses após a inoculação, as raízes foram avaliadas quanto ao índice de galhas e ao Fator de Reprodução (FR). No tomateiro, as avaliações foram feitas aos três meses após a inoculação. Não se verificou a ocorrência de galhas ou multiplicação dos nematoides nos genótipos avaliados, com exceção do porta-enxerto 'Nagano Wild', onde se registraram 36 galhas, porém sem evidência de multiplicação do nematoide. Os genótipos testados foram considerados imunes a esta espécie de nematoide das galhas, uma vez que foram eficazes em suprimir a reprodução de M. incognita, podendo ser usados como porta-enxertos alternativos em áreas de plantio com ocorrência desta praga de solo ou como fonte de resistência ao melhoramento genético de porta-enxertos de pessegueiro. Abstract in english In order to evaluate the reaction of the peach rootstocks 'Okinawa', 'Flordaguard', 'Nagano Wild', and the selection 'UFPel 0402' and 'NR-0080407' to Meloidogyne incognita, the plants were inoculated with 10.000 eggs+J2 of M. incognita. Seedlings of tomato 'Santa Cruz' inoculated in the same way were used as control and to determine the inoculum viability. The experiment was carried out under greenhouse conditions in a completely randomized experimental design with five r (more) eplications, each one performe by a plant. Six months after inoculation, the plants were pulled out on the roots and evaluated for the number of galls and reproduction factor (RF). Neither gall no nematode reproduction was registered in all rootstock systems, except for 'Nagano Wild' that shown 36 galls, but without evidences of nematode reproduction. All the tested genotypes were considered immune to this root-knot nematode specie, because they were effective in suppressing the M. incognita reproduction, and may be used as alternative rootstocks in new orchards or as resistance source to genetic improvement of peach rootstock.

Paula, Luciane Arantes de; Bianchi, Valmor João; Gomes, César Bauer; Fachinello, José Carlos

2011-06-01

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Reação de porta-enxertos de pessegueiro à Meloidogyne incognita Reaction of peach rootstocks to Meloidogyne incognita  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo foi avaliar a reação de cinco porta-enxertos de pessegueiro ao Meloidogyne incognita (Kofoid e White) Chitwood, em condições de casa de vegetação. Foram utilizados os porta-enxertos: 'Seleção UFPel 0402', 'Okinawa', 'Nagano Wild', 'Flordaguard' e 'Seleção NR-0080407'. As plantas foram inoculadas com 10.000 ovos+J2 de Meloidogyne incognita. Cinco plantas de tomateiro cv. Santa Cruz foram inoculadas para comprovação da eficiência do inóculo. O delineamento experimental foi o inteiramente casualizado, com cinco repetições e uma planta por parcela. Seis meses após a inoculação, as raízes foram avaliadas quanto ao índice de galhas e ao Fator de Reprodução (FR). No tomateiro, as avaliações foram feitas aos três meses após a inoculação. Não se verificou a ocorrência de galhas ou multiplicação dos nematoides nos genótipos avaliados, com exceção do porta-enxerto 'Nagano Wild', onde se registraram 36 galhas, porém sem evidência de multiplicação do nematoide. Os genótipos testados foram considerados imunes a esta espécie de nematoide das galhas, uma vez que foram eficazes em suprimir a reprodução de M. incognita, podendo ser usados como porta-enxertos alternativos em áreas de plantio com ocorrência desta praga de solo ou como fonte de resistência ao melhoramento genético de porta-enxertos de pessegueiro.In order to evaluate the reaction of the peach rootstocks 'Okinawa', 'Flordaguard', 'Nagano Wild', and the selection 'UFPel 0402' and 'NR-0080407' to Meloidogyne incognita, the plants were inoculated with 10.000 eggs+J2 of M. incognita. Seedlings of tomato 'Santa Cruz' inoculated in the same way were used as control and to determine the inoculum viability. The experiment was carried out under greenhouse conditions in a completely randomized experimental design with five replications, each one performe by a plant. Six months after inoculation, the plants were pulled out on the roots and evaluated for the number of galls and reproduction factor (RF). Neither gall no nematode reproduction was registered in all rootstock systems, except for 'Nagano Wild' that shown 36 galls, but without evidences of nematode reproduction. All the tested genotypes were considered immune to this root-knot nematode specie, because they were effective in suppressing the M. incognita reproduction, and may be used as alternative rootstocks in new orchards or as resistance source to genetic improvement of peach rootstock.

Luciane Arantes de Paula; Valmor João Bianchi; César Bauer Gomes; José Carlos Fachinello

2011-01-01

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Resistência de cultivares de batata-doce a Meloidogyne incognita Resistance of sweet potato cultivars to Meloidogyne incognita  

Directory of Open Access Journals (Sweden)

Full Text Available O presente trabalho teve o objetivo de estudar a resistência em 35 cultivares de batata-doce (Ipomoea batatas) a Meloidogyne incognita, bem como documentar alterações anatômicas em tecidos de raízes de cultivares infetadas. As plantas foram inoculadas em vasos com 3.000 ovos e juvenis de segundo estádio do nematóide e avaliadas aos 90 dias após com base no fator de reprodução (FR). Entre as 35 cultivares 15 foram consideradas resistentes. Alterações anatômicas nas raízes de cultivares suscetíveis são ilustradas, observando-se bloqueio de vasos do xilema e supressão de tecidos vasculares.The objectives of this study were to evaluate the resistance of 35 sweet potato (Ipomoea batatas) cultivars to Meloidogyne incognita and illustrating anatomical changes in tissue of infected plants. The plants were inoculated with 3,000 eggs and juveniles of M. incognita and evaluated at 90 days after inoculation based on the reproduction factor of the nematode (RF). Among the 35 cultivars tested, 15 of them were considered resistant. Anatomical changes in sweet potato roots are illustrated, showing interruption of xylem vessels and progressive suppression of vascular tissues.

Maria J. A. Wanderley; Jaime M. Santos

2004-01-01

31

Meloidogyne incognita on society garlic and its control.  

UK PubMed Central (United Kingdom)

Society garlic (Tulbaghia violacea) was heavily parasitized by the root-knot nematode Meloidogyne incognita. Few galls were apparent on infested plants, but numerous mature egg masses were evident throughout the root system. Immersion of rhizomes and roots in a hot water bath at 25, 47.5, 50, 52.5, 55, or 57.5 C for 2.5, 5, 7.5, 10, or 15 min was investigated as a control measure. All treatments at 50 C or higher and intervals of 5, 7.5, and 15 min at 47.5 C eliminated recovery of M. incognita. Excellent recovery was obtained from the controls at 25 C. Severe plant damage occurred at 52.5 C or higher or with 15-min exposures at 50 C. Optimum nematode control with minimum plant damage was achieved with exposure at 50 C for 2.5 min or at 47.5 C for 15 min.

McSorley R; McMillan RTJr; Parrado JL

1984-02-01

32

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

Directory of Open Access Journals (Sweden)

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.

MACIEL S.L.; FERRAZ L.C.C.B.

1996-01-01

33

RESPUESTA DE GENOTIPOS DE SOLANÁCEAS FRENTE A Meloidogyne incognita (KOFOID Y WHITE) CHITWOOD RAZA 2 Y M. arenaria (NEAL) CHITWOOD/ RESPONSE OF DIFFERENT GENOTYPES OF SOLANACEAE TO Meloidogyne incognita (KOFOID AND WHITE) CHITWOOD RACE 2 AND M. arenaria (NEAL) CHITWOOD  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Con el objetivo de conocer el grado de resistencia/susceptibilidad de seis genotipos de solanáceas, frente a Meloidogyne incognita raza 2 y de M. arenara, en macetas, se inocularon las plantas con tres niveles de nematodo (0,5, 1,5 y 2,5 huevos - J2.g de suelo-1). Se utilizó como control susceptible la variedad de tomate Campbell-28. Para la categorización de los genotipos se determinó el Índice de Agallamiento (IA), el Factor de Reproducción (FR) y el Índice de Re (more) producción (IR) de los nematodos, siguiendo la metodología establecida. Los genotipos S. torvum y S. erianthum tuvieron un comportamiento inmune frente M. incognita y altamente resistentes a M. arenaria. S. mammosum fue altamente resistente a ambas especies pero su eficiencia disminuyó cuando se enfrentó al nivel más alto de M. incognita. Los cultivares de tomate Motelle y Rossol fueron altamente resistentes a M. incognita. D. stramoniun no mostró síntomas de agallamiento ni grado de reproducción de los nematodos por lo que se clasificó como inmune para ambas especies. La población de M. arenaria se mostró más virulenta que la de M. incognita raza 2. Se discute la respuesta mostrada por los genotipos y las poblaciones de Meloidogyne, así como los posibles usos de los genotipos como patrones porta injertos. Abstract in english The resistance/susceptibility of six solanaceous genotypes to Meloidogyne incognita race 2 and M. arenaria were assessed, under a range of population densities (0,5, 1,5 and 2,5 eggs - J2.g of soil-1) of both nematodes. The plants were grown in pots in a greenhouse. The tomato variety Campbell-28 was used as a susceptible control. The gall index, reproductive index and reproductive factor were the parameter evaluated to assign a resistance/susceptible category of the geno (more) types according to the established methodology. S. torvum and S. erianthum were immune to M. incognita whereas they were highly resistant to M. arenaria with no significant differences at any inoculum level. S. mammosum responded as highly resistant to both populations but the efficiency was negatively affected by the highest level of M. incognita. The tomato cultivars Motelle and Rossol were also highly resistant to M. incognita. D. stramoniun was classified as immune to both M incognita and M. arenaria populations as no symptoms or reproduction of the nematode were observed on its roots. M. arenaria population appeared to be more virulent than the population of M. incognita race 2. The reaction of the genotypes and nematodes, as well as the possible use of the genotypes as stocks for grafting are discussed.

González, Farah María; Gómez, Lucila; Rodríguez, Mayra G; Piñón, Maité; Casanova, A; Gómez, Olimpia; Rodríguez, Yaritza

2010-04-01

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Varietal screening of Cicer arietinum against root knot nematode, Meloidogyne incognita  

Directory of Open Access Journals (Sweden)

Full Text Available Forty seven chickpea accessions were evaluated for their reaction to Meloidogyne incognita in pot experiments. Three-week-old seedlings were inoculated with 1000 freshly hatched juveniles of M. incognita. Sixty days after inoculation the plants wereuprooted and examined for galls, number of eggs/egg mass, root/shoot lengths and weights, and final nematode population. Variety RSG 564 was the most susceptible, developing the highest number of galls, eggs/egg mass and final nematode population, and variety RSG 617 was the least susceptible showing the lowest number of galls, eggs/egg mass and final nematode population and the highest root/shoot lengths and weights. All the other varieties exhibited degrees of susceptibility between RSG 564 and RSG 617.

CHARU JAIN* and P.C. TRIVEDI

2012-01-01

35

Pathogenicity of Pythium aphanidermatum to Chrysanthemum in Combined Inoculations with Belonolaimus longicaudatus or Meloidogyne incognita  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rooted cuttings of 'Iceberg' chrysanthemum in steamed soil were inoculated with the nematodes Belonolaimus longicaudatus, and Meloidogyne incognita, alone and combined with Pythium aphanidermatum, a fungus pathogen of chrysanthemum. B. longicaudatus alone severely restricted the root system; with P....

Johnson, A. W.; Littrell, R. H.

36

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 millefo (more) lium (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. Abstract in english 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, Bry (more) ophyllum 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.

MACIEL, S.L.; FERRAZ, L.C.C.B.

1996-05-01

37

Reproduction and Development of Meloidogyne incognita and M. javanica on Guardian Peach Rootstock  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Guardian peach rootstock was evaluated for susceptibility to Meloidogyne incognita race 3 (Georgia-peach isolate) and M. javanica in the greenhouse. Both commercial Guardian seed sources produced plants that were poor hosts of M. incognita and M. javanica. Reproduction as measured by number of egg m...

Nyczepir, A. P.; Beckman, T. G.; Reighard, G. L.

38

RNA interference-mediated growth control of the southern root-knot nematode Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

The Southern root-knot nematode Meloidogyne incognita causes huge crop losses. We investigated the effects of RNA interference directed against the M. incognita posterior segregation-1 gene. The RNAi resulted in a drastic reduction in the relative amount of pos-1 transcript. Also, it reduced reproductive potential in terms of hatching rate from eggs, probably due to embryonic lethality.

Matsunaga Y; Kawano K; Iwasaki T; Kawano T

2012-01-01

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Application of Alkaline-stabilized Biosolids for Meloidogyne incognita Suppression in Microplots  

Science.gov (United States)

N-Viro Soil (NVS) is an alkaline-stabilized biosolid that has been shown to suppress Meloidogyne incognita. In separate studies NVS was applied in microplots either at different rates (0, 25, 50, 75 and 100 dry t/ha), or applied in combination with M. incognita resistant and susceptible varieties a...

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Effect of Tropical Rotation Crops on Meloidogyne incognita and Other Plant-Parasitic Nematodes.  

UK PubMed Central (United Kingdom)

In a field experiment conducted on sandy soil in Florida during the 1993 season, rotation crops of castor (Ricinus communis), velvetbean (Mucuna deeringina), 'Mississippi Silver' cowpea (Vigna unguiculata), American jointvetch (Aeschynomene americana), 'Dehapine 51' cotton (Gossypium hirsutum), and 'SX-17' sorghum-sudangrass (Sorghum bicolor x S. sudanense) were effective in maintaining low population densities (<12/100 cm(3) soil) of Meloidogyne incognita race 1, whereas high population densities (>450/100 cm(3) soil) resulted after 'Clemson Spineless' okra (Hibiscus esculentus) and 'Kirby' soybean (Glycine max). Following a winter cover crop of rye (Secale cereale), densities of M. incognita following the six most effective rotation crops (1993 season) remained relatively low (incognita. A separate microplot experiment conducted in 1994 revealed that final densities (Pf) of M. incognita race 1 following 13 different crop cultivars were lower (P Meloidogyne spp. be evaluated for their response to other nematode pests as well.

McSorley R; Dickson DW

1995-12-01

 
 
 
 
41

Nematotoxic phenolic compounds from Melia azedarach against Meloidogyne incognita.  

Science.gov (United States)

In the present study, evaluated was the paralysis activity of whole Italian and Algerian Melia azedarach, commonly known as chinaberry, fruits and parts (seeds, wood, and kernels) against Meloidogyne incognita second stage juveniles (J(2)). The paralysis activity was evaluated in vitro after 1 h and 1 day immersion periods of nematodes in test solutions. Phenolic constituent components of the extracts were identified and quantified by high-performance liquid chromatography-mass spectrometry, while confirmation was performed by high-performance liquid chromatography-diode array. The water extract of the Italian M. azedarach fruit pulp (IPWE) showed significant nematicidal activity (EC(50/48h) = 955 ?g/mL) and among its active ingredient components were p-coumaric acid and p-hydroxybenzoic acid (EC(50/48h) = 840 and 871 ?g/mL, respectively). This is the first report of the nematicidal activity of M. azedarach pulp water extract and phenolic acids against the root knot nematode M. incognita. PMID:23136941

Aoudia, Hassiba; Ntalli, Nikoletta; Aissani, Nadhem; Yahiaoui-Zaidi, R; Caboni, Pierluigi

2012-11-19

42

Nematotoxic phenolic compounds from Melia azedarach against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

In the present study, evaluated was the paralysis activity of whole Italian and Algerian Melia azedarach, commonly known as chinaberry, fruits and parts (seeds, wood, and kernels) against Meloidogyne incognita second stage juveniles (J(2)). The paralysis activity was evaluated in vitro after 1 h and 1 day immersion periods of nematodes in test solutions. Phenolic constituent components of the extracts were identified and quantified by high-performance liquid chromatography-mass spectrometry, while confirmation was performed by high-performance liquid chromatography-diode array. The water extract of the Italian M. azedarach fruit pulp (IPWE) showed significant nematicidal activity (EC(50/48h) = 955 ?g/mL) and among its active ingredient components were p-coumaric acid and p-hydroxybenzoic acid (EC(50/48h) = 840 and 871 ?g/mL, respectively). This is the first report of the nematicidal activity of M. azedarach pulp water extract and phenolic acids against the root knot nematode M. incognita.

Aoudia H; Ntalli N; Aissani N; Yahiaoui-Zaidi R; Caboni P

2012-11-01

43

Behavioural response of Meloidogyne incognita to benzyl isothiocyanate  

UK PubMed Central (United Kingdom)

The breakdown of brassicaceous plant material produces nematotoxic isothiocyanates (ITCs). However, after the incorporation of brassicaceous plant material into soil, many nematodes are likely to be exposed only to sublethal concentrations of these compounds. Although unknown, the effect of these low ITC concentrations on the behaviour of plant-parasitic nematodes could play a role in nematode suppression. To address this question, the behaviour of infective second-stage juveniles (J2) of Meloidogyne incognita was evaluated following in vitro exposure to sublethal concentrations of benzyl isothiocyanate (BITC). Behaviour was qualitatively and quantitatively affected. Overall nematode activity in treatment groups scored visually, and individual nematode movement frequencies, quantified by video assay, were each significantly reduced within 2 h of exposure to 0.01 mM BITC. All responses were dose dependent. Infectivity of BITC-treated J2 of M. incognita on soybean (Glycine max) was measured directly by root staining and gall rating, and indirectly by egg production. All experiments showed significantly reduced infectivity after treatment of J2 with 0.01 mM BITC. In addition, egg production was almost completely eliminated (<5% of control) by 0.03 mM BITC. The correlation between the effect of BITC concentrations on J2 activity and infectivity was positive, with decreased J2 activity and infectivity resulting in decreased egg production. BITC concentrations that do not cause mortality significantly affect the behaviour of M. incognita J2, indicating that sublethal concentrations contribute to the overall nematode suppression by brassicaceous green manures.

Zasada IngaA; Masler EdwardP; Rogers StephenT; Halbrendt JohnM

2009-01-01

44

Variability in reproduction of isolates of Meloidogyne incognita and Meloidogyne javanica on resistant tomato genotypes.  

UK PubMed Central (United Kingdom)

Variability in reproduction and root galling of eight isolates of Meloidogyne incognita and seven isolates of M. javanica on Mi gene-based resistant tomato (Lycopersicon esculentum) was studied in greenhouse experiments. Fresh-market cultivars Castlemart (susceptible); Valerie, Royal Flush, Jackpot, Super Fantastic, Better Boy, Cavalier, President, Carmen, and Duchess (all resistant); and processing tomato cultivars and advanced lines UC82 (susceptible) and VFN8, GS27, Hy9889, XPH671, CX8202, MOX3076, and MOX3078 (all resistant) were tested. The M. incognita isolates did not vary in pathogenicity. The resistant tomatoes, except Valerie, were highly resistant to M. incognita, supporting egg production in most combinations at less than 2% of that on susceptible controls. Valerie was a mixture of fully susceptible and highly resistant individual plants, indicating segregation for resistance in this cultivar. Five M. javanica isolates also reproduced on resistant tomatoes, except Valerie, at less than 2% of their reproduction on susceptible controls; some of these isolates reproduced more on CX8202 and MOX3078 than on other resistant tomatoes. However, two additional M. javanica isolates reproduced more than the other isolates on resistant cultivars and lines; their egg production varied significantly (P ?0.05) with cultivar from low (highly resistant) to intermediate (moderately resistant) compared with that on susceptible controls for each isolate. No resistant tomato cultivar or line was immune to any nematode isolate.

Roberts PA; Thomason IJ

1986-06-01

45

Susceptibilidad de genotipos de Solanum lycopersicum L. frente a Meloidogyne incognita Kofoid y White (Chitwood)/ Susceptibility of Solanum lycopersicum L. genotypes against Meloidogyne incognita Kofoid & White (Chitwood)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se evaluó la resistencia/susceptibilidad de los genotipos Aro 8484, HA 3063, Caramba y HA 8476 de Solanum lycopersicum L. frente a Meloidogyne incognita Kofoid y White (Chitwood) raza 2 y se determinó la influencia de este nematodo sobre su crecimiento. Se establecieron dos experimentos en condiciones semi-controladas, en macetas de 1,5L de capacidad. En el primero, cada genotipo, incluyendo el control susceptible tomate cv. Campbell-28, se inoculó con 1,5 J2. g de sue (more) lo-1. Para la categorización de los genotipos en resistentes/susceptibles se determinó el índice de agallamiento, el factor de reproducción y el índice de reproducción del nematodo. En el segundo experimento los genotipos se inocularon con 0; 0,5; 1,5 y 2,5 J2. g de suelo-1. Los cuatro genotipos con niveles 0 de nematodos constituyeron los controles. Cada experimento contó con 10 réplicas por tratamiento con una distribución aleatoria en casas de vegetación. Se realizó un análisis de regresión lineal para establecer la relación entre los niveles de nematodos y la altura de las plantas. Todos los genotipos fueron susceptibles a M. incognita. Se demostró que entre el 60 y el 94% de la disminución del tamaño de las plantas está relacionado con el aumento de las poblaciones del nematodo. No se recomienda el uso de estos genotipos en instalaciones de producción protegida de hortalizas con suelos infestados por M. incognita, sin antes establecer medidas de manejo que disminuyan las poblaciones por debajo de 0,5 J2.g de suelo-1. Abstract in english The resistance/susceptibility of Solanum lycopersicum L genotypes Aro 8484, HA 3063, Caramba and HA 8476 against Meloidogyne incognita Kofoid and White (Chitwood) race 2 and the influence of the nematode on the genotype growths were evaluated in two experiments under semi-controlled conditions. In the first experiment, the genotypes, including a susceptible control tomato Campbell-28, were inoculated with a level of 1,5 J2. g of soil-1. Root gall index, was reproduction f (more) actor and reproduction index of the nematode were determined for categorizing resistant/susceptible genotypes. In the second experiment, three levels of nematodes (0,5; 1,5 and 2,5 J2. g of soil-1) were used. Not inoculated genotypes were established as a control. Both experiments had 10 repetitions and were placed in a green house using a randomized distribution design. A lineal regression analysis was used to establish the relation of nematode levels and the plant growths. All genotypes were susceptible to M. incognita. It was demonstrated that the 60 to 94% of plant growth decrease related to the nematode population increase. The use of genotypes is not recommended in soils infected with M. incognita unless management measures are established for keeping nematode population below 0,5 J2.g of soil-1.

Gómez, Lucila; Enrique, R; Hernández-Ochandía, Dainé; Miranda, Ileana; González, E; Peteira, Belkis; Rodríguez, Mayra G

2012-08-01

46

Melia azedarach controls Meloidogyne incognita and triggers plant defense mechanisms on cucumber  

UK PubMed Central (United Kingdom)

Melia azedarach fruit extracts have recently raised a substantial interest for their use in crop protection against phytoparasitic nematodes. The effect of M. azedarach on the root-knot nematode Meloidogyne incognita on cucumber, as well as the effect on the plant deference mechanism, is reported herein. Crushed fruits of M. azedarach, tested in the soil at the rates of 30 and 60 g kg?1, exhibited nematicidal activity similar to the one of fenamiphos (0.02 g a.i. kg?1) in terms of nematode population in roots and soil as well as reproduction rate. M. azedarach water extracts, rich in aldehydes, alcohols and carboxylic acids, showed nematicidal activity against M. incognita. Moreover, all M. azedarach treatments decreased the activities of catalase (CAT) and peroxidase (POX) involved in host H2O2 detoxification. Soil application of M. azedarach fruits could be favourably considered in the control of M. incognita on cucumber in a sustainable agriculture, since they act directly as nematicidals. Furthermore, M. azedarach elicits plant defence and helps the host to fight the nematodes infestation in an indirect way.

Cavoski I; Chami ZA; Bouzebboudja F; Sasanelli N; Simeone V; Mondelli D; Miano T; Sarais G; Ntalli NG; Caboni P

2012-05-01

47

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 muda foi infestada com 8.000 ovos, passados cinco meses do transplante, e a avaliação, efetuada seis meses depois. No segundo experimento, as mudas foram infestadas cerca de um ano do transplante com 7.000 ovos cada uma e a avaliação realizada decorridos dez meses. Todas as plantas foram infestadas pelas raças 1 e 2; entretanto, a reprodução do nematóide foi menor nas plantas mais velhas. As raças 3 e 4 apresentaram baixas infestações e algumas reações de imunidade, principalmente a 4, que tem pouca importância prática pela sua pequena ocorrência. Os cultivares de Catuaí revelaram médias de notas de ootecas menores que as das linhagens de 'Mundo Novo', indicando menor suscetibilidade. Contudo, é importante ressaltar que a menor infestação não significa que as raças 3 e 4 sejam menos danosas ao cafeeiro quando o parasitam em campo.Two experiments were carried out in Campinas, State of São Paulo, Brazil, to evaluate the resistance of young trees of seven lines of Coffea arabica ('Mundo Novo': CP388-17, CP379-19, CP501 and MP376-4; 'Catuaí Yellow' H2077-2-5-62 and 'Catuaí Red' H2077-2-5-81; and 'Caturra Yellow' and two of C. canephora (Robusta: 'Guarini' col, 10 and 'Kouillon' col. 67-14) to the four races of Meloidogyne incognita in pots. In the first experiment, each plant was infested five months after transplanting with 8000 eggs, and evaluated six months later. In the second experiment, the plants were infested near one year after transplanting with 7000 eggs each one, and evaluated ten months later. Races 1 and 2 infested all cultivars, however, nematode reproduction was lower in the older plants. Races 3 and 4 presented low infestation and some imunity reactions (race 4, mainly) what does not have any practical importance since they have a low frequence of occurrence. Catuaí cultivars presented lower egg-mass notes than Mundo Novo cultivars indicating some degree of resistance. However, the low levels of infestation observed do not necessarily indicate that these races will not damage coffee plants under field conditions.

Rubens Rodolfo Albuquerque Lordello; Ana Ines Lucena Lordello

1987-01-01

48

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

Scientific Electronic Library Online (English)

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

Mayer, Newton Alex; Pereira, Fernando Mendes; Santos, Jaime Maia dos

2005-08-01

49

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

Directory of Open Access Journals (Sweden)

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

Newton Alex Mayer; Fernando Mendes Pereira; Jaime Maia dos Santos

2005-01-01

50

Sensitivity of Bedding Plants to Southern Root-knot Nematode, Meloidogyne incognita Race 3.  

Science.gov (United States)

Thirty-two cultivars of 10 commonly-grown bedding plants, representing eight families, were evaluated for their response to infection by the root-knot nematode, Meloidogyne incognita race 3, under greenhouse conditions. Four ageratum cultivars, two marigold, and two salvia cultivars were rated resistant after exposure for 8 weeks. Four begonia, four celosia, one dianthus, one verbena, one vinca, and three pansy cultivars were susceptible. Three salvia, one begonia, one gerber, one verbena, and three vinca cultivars were slightly susceptible with an average of population densities, affected the dry weights of only a few cultivars. The diversity of annual bedding plant germplasm available may provide adequate sources of resistance to this race of root-knot nematode. PMID:19279964

Walker, J T; Melin, J B; Davis, J

1994-12-01

51

Sensitivity of Bedding Plants to Southern Root-knot Nematode, Meloidogyne incognita Race 3.  

UK PubMed Central (United Kingdom)

Thirty-two cultivars of 10 commonly-grown bedding plants, representing eight families, were evaluated for their response to infection by the root-knot nematode, Meloidogyne incognita race 3, under greenhouse conditions. Four ageratum cultivars, two marigold, and two salvia cultivars were rated resistant after exposure for 8 weeks. Four begonia, four celosia, one dianthus, one verbena, one vinca, and three pansy cultivars were susceptible. Three salvia, one begonia, one gerber, one verbena, and three vinca cultivars were slightly susceptible with an average of population densities, affected the dry weights of only a few cultivars. The diversity of annual bedding plant germplasm available may provide adequate sources of resistance to this race of root-knot nematode.

Walker JT; Melin JB; Davis J

1994-12-01

52

Fusarium oxysporum f. sp. phaseoli and Meloidogyne incognita interaction in common bean/ Interação entre Fusarium oxysporium f. sp. e Meloidogyne incognita em feijoeiro-comum  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Com objetivo de verificar se há associação entre a resistência ao nematóide e ao Fusarium oxysporum (Fop), dezoito linhagens de feijão, sendo oito resistentes e oito suscetíveis ao Fop mais duas testemunhas foram avaliadas com relação à reação ao nematóide Meloidogyne incognita. Essa avaliação foi realizada em casa de vegetação no delineamento de blocos casualizados com cinco repetições. A parcela foi constituída por um vaso com duas plantas de feijão (more) , e uma de tomate suscetível ao nematóide. Aos 15 dias após a semeadura, foi realizada a infestação, na região da rizosfera, com 5000 ovos de Meloidogyne incognita, raça 3. Foi avaliado o número de massas de ovos, aproximadamente 45 dias após a inoculação. Somente as linhagens ESAL 522, ESAL 519 e 'Aporé' foram resistentes ao nematóide. Apenas a 'Aporé' foi resistente aos dois patógenos. A correlação entre as notas de severidade do Fop e o número médio de massa de ovos obtida foi praticamente nula (r = 0,0252; Abstract in english To verify a possible relationship between resistance to nematodes and to Fusarium oxysporum (Fop) in common bean, 18 lines (eight resistant and eight susceptible to Fop plus two controls) were evaluated for resistance to the nematode Meloidogyne incognita. This evaluation was conducted in a greenhouse in a randomized block design with five replications. The plot consisted of one pot with two bean plants and a nematode-susceptible tomato plant. Two weeks after sowing, plan (more) ts were infested in the rhizosphere with 5000 eggs of Meloidogyne incognita, race 3. The number of egg masses was assessed, about 45 days after inoculation. Only lines ESAL 522, ESAL 519 and 'Aporé' were resistant to the nematode. Only 'Aporé' was resistant to both pathogens. The correlation between grades of Fop severity and mean egg mass was practically zero (r = 0.0252, P

Carneiro, Flávia Fernandes; Ramalho, Magno Antonio Patto; Pereira, Mônica Juliani Zavaglia

2010-09-01

53

Meloidogyne incognita Resistance Characteristics in Tomato GenotypesDeveloped for Processing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nine resistant processing tomato (Lycopersicon esculentum) cultivars and advanced lines were compared with four susceptible cultivars in 1,3-dichloropropene-fumigated and nontreated plots on Meloidogyne incognita-infested sites over 3 years. Yield of all resistant genotypes grown in nontreated and n...

Roberts, P. A.; May, D.

54

Effect of Meloidogyne incognita on Plant Nutrient Concentration and Its Influenceon the Physiology of Beans  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Phaseolus vulgaris plants, 3, 8, 11, and 13 days old, were inoculated with 0, 2,000, 4,000, or 8,000 second-stage Meloidogyne incognita larvae and maintained under controlled conditions. The photosynthetic rate and the shoot and root concentration of K, Ca, Mn, Fe, Cu, and Zn were determined by dest...

Melakeberhan, H.; Webster, J. M.; Brooke, R. C.; D'Auria, J. M.; Cackette, M.

55

Fosthiazate Controls Meloidogyne arenaria and M. incognita in Flue-Cured Tobacco  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The nematicide fosthiazate was evaluated over a 3-year period for management of Meloidogyne incognita race 3 (site 1) and M. arenaria race 2 (site 2) in flue-cured tobacco. Fosthiazate was applied broadcast and incorporated at rates ranging from 22 to 88 g a.i./100 m², and compared with the nematici...

Pullen, M. P.; Fortnum, B. A.

56

The Relationship of Meloidogyne incognita acrita to the Incidence of Cabbage Yellows.  

Science.gov (United States)

Three inoculum level combinations of Meloidogyne incognita acrita and Fusariurn oxysporurn f. conglutinans did not affect the incidence of cabbage yellows in the moderately-resistant 'Greenback' or the highly-resistant 'Marion Market' varieties. The susceptible 'Early Round Dutch' variety was more susceptible to low levels of fungus inoculum in the presence of the nematode. PMID:19325680

Fassuliotis, G; Rau, G J

1969-07-01

57

The Relationship of Meloidogyne incognita acrita to the Incidence of Cabbage Yellows.  

UK PubMed Central (United Kingdom)

Three inoculum level combinations of Meloidogyne incognita acrita and Fusariurn oxysporurn f. conglutinans did not affect the incidence of cabbage yellows in the moderately-resistant 'Greenback' or the highly-resistant 'Marion Market' varieties. The susceptible 'Early Round Dutch' variety was more susceptible to low levels of fungus inoculum in the presence of the nematode.

Fassuliotis G; Rau GJ

1969-07-01

58

Influence of Maize Rotations on the Yield of Soybean Grown in Meloidogyne incognita Infested Soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A replicated field study was conducted from 1972 to 1980 involving soybeans grown in 2-, 3-, and 4-year rotations with maize in soil infested with Meloidogyne incognita. Monocultured soybeans were maintained as controls. Cropping regimes involved root-knot nematode susceptible and resistant soybean ...

Kinloch, Robert A.

59

Modification of Resistance Expression of Phaseolus vulgaris to Meloidogyne incognita by Elevated Soil Temperatures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The effect of temperature on the reaction of susceptible (Canario Divex) and resistant (A 211) bean pure lines to Meloidogyne incognita was studied with soil temperature tanks housed in a growth chamber at 22 or 24 C. Soil temperature remained constant at 16, 22, 24, 26, 30, or 32 C in several trial...

Mullin, B. A.; Abawi, G. S.; Pastor-Corrales, M. A.

60

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

 
 
 
 
61

Effects of Management Practices on Meloidogyne incognita and Snap Bean Yield  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Phenamiphos applied at 6.7 kg ai/ha through a solid set or a center pivot irrigation system with 28 mm of water effectively controlled root-knot nematodes, Meloidogyne incognita, and resulted in greater snap bean growth and yields irrespective of growing season, tillage method, or cover crop system....

Smittle, D. A.; Johnson, A. W.

62

Autoradiography of Developing Syncytia in Cotton Roots Infected withMeloidogyne incognita  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cotton (Gossypium hirsutum) seedlings, uniformly infected with Meloidogyne incognita, were exposed for periods of 1-15 days to a nutrient solution containing tritium-labelled thymidine. Syncytium formation began with the amalgamation of cells near the nematode head, and was followed by synchronized ...

Rohde, R. A.; McClure, M. A.

63

PLANTAGO LANCEOLATA AND PLANTAGO RUGELII EXTRACTS ARE TOXIC TO MELOIDOGYNE INCOGNITA BUT NOT TO CERTAIN MICROBES  

Science.gov (United States)

Extracts from the plants Plantago lanceolata and P. rugelii were evaluated for toxicity to the root-knot nematode Meloidogyne incognita, the beneficial microbes Enterobacter cloacae, Pseudomonas fluorescens and Trichoderma virens, and the plant-pathogenic fungi Fusarium oxysporum f. sp. gladioli, Ph...

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Efficacy of MIDAS™ for Control of Meloidogyne incognita on Celosia in Florida  

Science.gov (United States)

The efficacy of iodomethane:chloropicrin (50:50 Midas™, Arysta LifeScience Corp., Cary, NC) was evaluated for control of root-knot nematodes (Meloidogyne incognita) on Celosia argentea var. cristata. A field trial was conducted on a commercial farm in southeastern Florida in 2006. Midas applied at ...

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Nematicidal effects of Leucaena leucocephala and Gliricidia sepium extracts on Meloidogyne incognita infecting okra  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two separate but identical greenhouse trials were conducted to investigate the effects of extracts of leaves and roots of Leucaena leucocephala and Gliricidia sepium each at 80,000 mg / kg and 40,000 mg / kg on Meloidogyne incognita on okra. Each potted nine-day old okra seedling was inoculated with...

Adekunle O.K.; Akinlua A.

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-06-01

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Amendment of soil with African marigold and sunn hemp for management of Meloidogyne incognita in selected legumes  

UK PubMed Central (United Kingdom)

Field experiments were conducted in 2008 and 2009 in the tropical rainforest zone of Nigeria to investigate the effects of amendment of soil with seedlings of African marigold (Tagetes erecta) and sunn hemp (Crotalaria juncea) incorporated singly in plots on Meloidogyne incognita and yield of cowpea and soybean. The experimental field, which was naturally free of plant-parasitic nematodes, was inoculated with chopped roots of M. incognita race 2-infected Celosia argentea roots and planted to tomato to increase M. incognita population at the site. Eight week-old marigold seedlings were incorporated in cowpea or soybean field and eight week-old sunn hemp seedlings were also incorporated in cowpea or soybean field. At the ends of the experiments, M. incognita population densities were significantly higher in control plots than those of the plots amended with marigold or sunn hemp with correspondingly higher grain yield in the amended plots in both cowpea and soybean fields in both years. A significantly higher population of the nematode and consequently, lower yield was associated with cultivar Ife Brown than cultivar Ife Bimpe of cowpea for each treatment whereas in soybean cultivars, the pattern was not definite. Also twelve seedlings of marigold or sunn hemp per plot incorporated into the soil produced significantly higher grain yield in cultivar Ife Brown of cowpea and cultivar TGX 1440 of soybean compared to six seedlings per plot. The results of this study suggest that incorporating marigold or sunn hemp in M. incognita-infected cowpea or soybean field has potentials to suppress M. incognita population and reduce nematode damage on yield of the associated leguminous crops.

Adekunle OK

2011-11-01

68

Produtos naturais aplicados para manejo de Meloidogyne incognita em tomateiros Natural products applied to the management of Meloidogyne incognita in tomato plants  

Directory of Open Access Journals (Sweden)

Full Text Available Este trabalho teve por objetivo avaliar o efeito de produtos naturais na expressão da resistência 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 inoculação do patógeno através da pulverização foliar, utilizando-se duas dosagens para cada indutor. A inoculação do nematoide foi realizada 30 dias após o plantio, usando-se 5000 ovos/ planta. Avaliando-se o número de ovos e o fator de reprodução, 30 dias após a inoculação, observou-se que todos os tratamentos diferiram estatisticamente da testemunha, impedindo o aumento da população inicial do patógeno. Dentre os indutores, o indutor silicatado Rocksil foi o que apresentou os melhores resultados para o controle da meloidoginose em todas as épocas de aplicação e em todas as dosagens. Contudo, plantas tratadas com o produto apresentaram baixos pesos de parte aérea sugerindo que houve um custo adaptativo de resistência. Considerando-se o fator de reprodução não foram observadas diferenças estatísticas quando comparadas a dosagem e época de aplicação entre os indutores, com exceção da Quitosana aplicada aos 5 dias antes da inoculação e do Neemseto aplicado aos 15 dias antes da inoculação do nematóide.This study aimed to evaluate the effect of natural products on the expression of resistance to Meloidogyne incognita in organically produced tomato plants. The inducers Rocksil, Chitosan, Neemseto and Biopirol were applied at 5, 10 and 15 days as independent treatments before the pathogen inoculation by means of leaf spraying, using two levels for each inducer. The nematode inoculation was performed at 30 days after planting, using 5000 eggs/plant. Evaluating the number of eggs and the reproduction factor, at 30 days after inoculation, all treatments statistically differed from the control, preventing an increase in the initial population of the pathogen. Of the natural inducers, Rocksil showed the best results for controlling the root-knot nematode in all application times and at all levels. However, plants treated with the product had low shoot weights, suggesting that there was a fitness cost of resistance. Considering the reproduction factor, there were not statistical differences when the level and the application time were compared among natural inducers, except for Chitosan applied at 5 days before the nematode inoculation and Neemseto applied at 15 days before the nematode inoculation.

Thiago Anchieta de Melo; Ilka Márcia Ribeiro de Sousa Serra; Gilson Soares da Silva; Rosa Maria Souto de Sousa

2012-01-01

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Nematicidal effects of Leucaena leucocephala and Gliricidia sepium extracts on Meloidogyne incognita infecting okra  

Directory of Open Access Journals (Sweden)

Full Text Available Two separate but identical greenhouse trials were conducted to investigate the effects of extracts of leaves and roots of Leucaena leucocephala and Gliricidia sepium each at 80,000 mg / kg and 40,000 mg / kg on Meloidogyne incognita on okra. Each potted nine-day old okra seedling was inoculated with 3,000 fresh eggs of M. incognita and 5ml of each of the extracts was added simultaneously around the roots of the seedling. Treatment of okra plant with L. leucocephala and G. sepium extracts resulted in reduced nematode population, reduced galling, reduced nematode reproduction rate and enhanced fruit weight. Chemical analysis revealed that G. sepium leaves contained phenolic compound and carboxylic acid, while the roots showed the presence of aromatic amide, phenolic compound and carboxylic acid. L. leucocephala leaves showed the presence of phenolic compound, aromatic amide and carboxylic acid, while the roots showed the presence of phenolic compound and carboxylic acid. The results of this study suggest that leaf and root extracts of L. leucocephala and G. sepium at the rate of 40,000 mg / kg could be useful in root knot nematode management in vegetable beds.

Adekunle O.K.; Akinlua A.

2007-01-01

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Effect of Tropical Rotation Crops on Meloidogyne incognita and Other Plant-Parasitic Nematodes.  

Science.gov (United States)

In a field experiment conducted on sandy soil in Florida during the 1993 season, rotation crops of castor (Ricinus communis), velvetbean (Mucuna deeringina), 'Mississippi Silver' cowpea (Vigna unguiculata), American jointvetch (Aeschynomene americana), 'Dehapine 51' cotton (Gossypium hirsutum), and 'SX-17' sorghum-sudangrass (Sorghum bicolor x S. sudanense) were effective in maintaining low population densities (450/100 cm(3) soil) resulted after 'Clemson Spineless' okra (Hibiscus esculentus) and 'Kirby' soybean (Glycine max). Following a winter cover crop of rye (Secale cereale), densities of M. incognita following the six most effective rotation crops (1993 season) remained relatively low (incognita. A separate microplot experiment conducted in 1994 revealed that final densities (Pf) of M. incognita race 1 following 13 different crop cultivars were lower (P Meloidogyne spp. be evaluated for their response to other nematode pests as well. PMID:19277319

McSorley, R; Dickson, D W

1995-12-01

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Seed treatment affects Meloidogyne incognita penetration, colonization and reproduction on cotton/ Tratamento de sementes afeta a penetração, colonização e reprodução de Meloidogyne incognita em algodão  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O efeito de abamectina em tratamento de sementes na penetração, colonização e reprodução de Meloidogyne incognita, em algodão, foi avaliado em dois experimentos de casa de vegetação. A penetração de juvenis de segundo estádio (J2) foi avaliada aos três, nove e 15 dias após a germinação (dag), enquanto que a colonização 27dag foi avaliada por meio da contagem do número total de galhas e massas de ovos por sistema radicular. Ovos e J2 de M. incognita fora (more) m extraídos das raízes para determinar a reprodução do nematoide aos 50 e 100dag. O tratamento de sementes diminuiu a penetração dos J2 nas raízes, resultando em menor colonização e reprodução de M. incognita. Os resultados obtidos são discutidos tendo em vista os aspectos ambientais da presença de abamectina no solo e as práticas agrícolas 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 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 a (more) t 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.

Bessi, Rosana; Sujimoto, Fernando Ribeiro; Inomoto, Mário Massayuki

2010-06-01

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

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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.

Mahfouz M. M. Abd-Elgawad; Marie-Claire Kerlan; Sergio Molinari; Farid Abd-El-Kareem; Sanaa S. A. Kabeil; Moawad M. Mohamad; Wafaa A. El-Nagdi

2012-01-01

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Host suitability of Ixora spp. for the Root-knot Nematodes Meloidogyne incognita Race 1 and M. javanica  

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Eight commonly cultivated Ixora species or cultivars were tested for their suitability as hosts and their level of tolerance to Meloidogyne incognita race 1 and M. javanica in a greenhouse study. Twenty weeks postinoculation with 5,000 eggs per pot, M. incognita race 1 and M. javanica produced galls...

Giblin-Davis, Robin M.; Meerow, Alan W.; Bilz, Frank G.

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Efeitos do nível de inóculo de Meloidogyne incognita em algodoeiro  

Directory of Open Access Journals (Sweden)

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.

ABRÃO MARLUCI MUNDIN; MAZZAFERA PAULO

2001-01-01

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Nematicidal fluorescent pseudomonads for the in vitro and in vivo suppression of root knot (Meloidogyne incognita) of Capsicum annuum L.  

UK PubMed Central (United Kingdom)

BACKGROUND: Considerable attention has been paid to plant-growth-promoting rhizobacteria (PGPR), especially the fluorescent group of Pseudomonas species, as the best alternatives to chemicals for facilitating ecofriendly biological control of soil- and seedborne microorganisms. On the basis of their novel plant-growth-promoting attributes, two rhizobacteria Pseudomonas aeruginosa VP1 and VP2 selected out of over 63 isolates from the rhizosphere of chilli (Capsicum annuum) were identified as potential candidates for biocontrol of the root-knot nematode Meloidogyne incognita on chilli. RESULTS: The nematicidal activity of both strains was evaluated in vitro and in vivo for their efficacy against M. incognita. P. aeruginosa VP2 exhibited strong nematicidal activity in comparison with VP1, based on the in vitro killing of the second-stage juveniles (J2) of M. incognita. Seed bacterisation with both strains VP1 and VP2 was able to manage root-knot M. incognita on chilli (C. annuum) in a pot trial study. Increase in root and shoot length and in fresh and dry weight of root and shoot and reduction in the root-knot index over the control were attained. In overall performance, VP2 was 29.5% more effective than VP1, and about 30% more effective than the control (non-bacterised). CONCLUSION: The application of P. aeruginosa VP1 and P. aeruginosa VP2 controls the development of M. incognita in C. annuum, and hence they are recommended as efficient plant growth promotors and biocontrolling agents for raising healthy crop of C. annuum that can promote the growth of plants and reduce the nematode (M. incognita) population.

Wahla V; Maheshwari DK; Bajpai VK

2012-08-01

76

Nematicidal activities of natural lignans and derivatives from milky thistle against Meloidogyne incognita  

Directory of Open Access Journals (Sweden)

Full Text Available The nematicidal activity of varying concentrations of lignans and the various derivatives obtained from Silybum marianum was evaluated against root knot nematode Meloidogyne incognita (Kofoid and White) Chitwood. The percentage mortality and inhibition of hatching of M. incognita were found to be directly proportional to the concentration of compounds and derivatives on prolonged exposure. Overall, silybin pentabenzoate exhibited the highest nematicidal activity causing 99% mortality at 500 µg/ ml after 24 hours of exposure. The results obtained are the first experimental confirmation of nematicidal activity of these compounds, thereby might prove a boon for further development and understanding of plant derived nematicides.

Rakesh Pandey

2011-01-01

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Studies on the interactive effect of Meloidogyne incognita and Fusarium solani on Lycopersicon esculentum, Mill  

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Full Text Available A disease complex involving Meloidogyne incognita and Fusarium solani was studied on tomato (Lycopersicon esculentum, Mill.) under glasshouse conditions. Pot experiments were conducted to determine the pathogenesis of both the pathogens individually, simultaneously and sequentially. Isolates of M. incognita and F. solani singly caused a significant reduction in plant height, fresh weight, dry weight, number of fruits and fruit weight over the un-inoculated one but the reduction was more by M. incognita as compared to F. solani. A significant reduction in different plant growth parameters was observed on simultaneous and sequential inoculation of M. incognita and F. solani. However, the reduction was more prominent on simultaneous inoculation of both the pathogens. Among the sequential inoculations more damages were assessed during inoculation of M. incognita followed by F. solani (N+f10). Nematode multiplication, number of galls and number of females were adversely affected on simultaneous and sequential inoculation of both the pathogens in all the treatments. In the present study it was concluded that both the pathogens viz M. incognita and F. solani are virulent against the tomato c.v pusa ruby and therefore measures to prevent the spread of disease become important.

Mucksood Ahmad Ganaie; T.A. Khan

2011-01-01

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Proteomic profiles of soluble proteins from the esophageal gland in female Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

Meloidogyne incognita can infect multiple plant species. Proteins synthesized in the esophageal glands and secreted through the stylet of plant parasitic nematodes play critical roles in the plant-nematode interactions. Female M. incognita live for approximately 15days, embedded in a host plant, but their esophageal gland proteins have not yet been comprehensively analyzed. In this study, a new bacterium-contamination-resistant method for collecting soluble proteins from esophageal gland cells (SPEGC) of female M. incognita was established. Approximately 5?g of freeze-dried proteins could be extracted from 150 female M. incognita. Bands of a one-dimensional SDS-polyacrylamide gel were excised after electrophoresis of 20?g of protein and were analyzed. Two hundred and forty-six proteins from SPEGC of female M. incognita were identified by LC-MS/MS. Gene Ontology analysis suggests that many of the secreted proteins are involved in protein or carbohydrate metabolism and proteolysis. Some of the SPEGC (46.3%) were predicted to be secreted through classical or non-classical secretory pathways. The described method presents a new approach for the identification of proteins stored in SPEGC of an important plant parasitic nematode. This global proteomic profile of SPEGC provides a basis for future studies to elucidate the functions of proteins secreted from female M. incognita on plant responses.

Wang XR; Moreno YA; Wu HR; Ma C; Li YF; Zhang JA; Yang C; Sun S; Ma WJ; Geary TG

2012-12-01

79

Proteomic profiles of soluble proteins from the esophageal gland in female Meloidogyne incognita.  

Science.gov (United States)

Meloidogyne incognita can infect multiple plant species. Proteins synthesized in the esophageal glands and secreted through the stylet of plant parasitic nematodes play critical roles in the plant-nematode interactions. Female M. incognita live for approximately 15days, embedded in a host plant, but their esophageal gland proteins have not yet been comprehensively analyzed. In this study, a new bacterium-contamination-resistant method for collecting soluble proteins from esophageal gland cells (SPEGC) of female M. incognita was established. Approximately 5?g of freeze-dried proteins could be extracted from 150 female M. incognita. Bands of a one-dimensional SDS-polyacrylamide gel were excised after electrophoresis of 20?g of protein and were analyzed. Two hundred and forty-six proteins from SPEGC of female M. incognita were identified by LC-MS/MS. Gene Ontology analysis suggests that many of the secreted proteins are involved in protein or carbohydrate metabolism and proteolysis. Some of the SPEGC (46.3%) were predicted to be secreted through classical or non-classical secretory pathways. The described method presents a new approach for the identification of proteins stored in SPEGC of an important plant parasitic nematode. This global proteomic profile of SPEGC provides a basis for future studies to elucidate the functions of proteins secreted from female M. incognita on plant responses. PMID:23142006

Wang, Xin-Rong; Moreno, Yovany A; Wu, Han-Rong; Ma, Chao; Li, Yun-Feng; Zhang, Jin-Ai; Yang, Chong; Sun, Si; Ma, Wei-Jie; Geary, Timothy G

2012-11-08

80

Genome sequence of the metazoan plant-parasitic nematode Meloidogyne incognita.  

Science.gov (United States)

Plant-parasitic nematodes are major agricultural pests worldwide and novel approaches to control them are sorely needed. We report the draft genome sequence of the root-knot nematode Meloidogyne incognita, a biotrophic parasite of many crops, including tomato, cotton and coffee. Most of the assembled sequence of this asexually reproducing nematode, totaling 86 Mb, exists in pairs of homologous but divergent segments. This suggests that ancient allelic regions in M. incognita are evolving toward effective haploidy, permitting new mechanisms of adaptation. The number and diversity of plant cell wall-degrading enzymes in M. incognita is unprecedented in any animal for which a genome sequence is available, and may derive from multiple horizontal gene transfers from bacterial sources. Our results provide insights into the adaptations required by metazoans to successfully parasitize immunocompetent plants, and open the way for discovering new antiparasitic strategies. PMID:18660804

Abad, Pierre; Gouzy, Jérôme; Aury, Jean-Marc; Castagnone-Sereno, Philippe; Danchin, Etienne G J; Deleury, Emeline; Perfus-Barbeoch, Laetitia; Anthouard, Véronique; Artiguenave, François; Blok, Vivian C; Caillaud, Marie-Cécile; Coutinho, Pedro M; Dasilva, Corinne; De Luca, Francesca; Deau, Florence; Esquibet, Magali; Flutre, Timothé; Goldstone, Jared V; Hamamouch, Noureddine; Hewezi, Tarek; Jaillon, Olivier; Jubin, Claire; Leonetti, Paola; Magliano, Marc; Maier, Tom R; Markov, Gabriel V; McVeigh, Paul; Pesole, Graziano; Poulain, Julie; Robinson-Rechavi, Marc; Sallet, Erika; Ségurens, Béatrice; Steinbach, Delphine; Tytgat, Tom; Ugarte, Edgardo; van Ghelder, Cyril; Veronico, Pasqua; Baum, Thomas J; Blaxter, Mark; Bleve-Zacheo, Teresa; Davis, Eric L; Ewbank, Jonathan J; Favery, Bruno; Grenier, Eric; Henrissat, Bernard; Jones, John T; Laudet, Vincent; Maule, Aaron G; Quesneville, Hadi; Rosso, Marie-Noëlle; Schiex, Thomas; Smant, Geert; Weissenbach, Jean; Wincker, Patrick

2008-07-27

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

Science.gov (United States)

Thirty-two weed species common in South Carolina and one cultivar of tobacco were evaluated as hosts of Meloidogyne arenaria race 2 and M. incognita race 3 in the greenhouse. Egg mass production and galling differed (P Rumex crispus, Amaranthus hybridus, Ambrosia artemisiifolia, lpomoea hederacea var. integriuscula, Setaria lutescens, Sida spinosa, Portulaca oleracea, and Rumex acetosella were moderate hosts. Taraxacum officinale, Ipomoea hederacea, Cyperus esculentus, Cynodon dactyIon, Echinochloa crus-galli, Eleusine indica, Sorghum halepense, Setaria viridis, Digitaria sanguinalis, and Datura stramonium were poor hosts for M. arenaria. Amaranthus palmeri, Amaranthus hybridus, Chenopodium album, Euphorbia maculata, Setaria lutescens, Vicia villosa, Sida spinosa, Rumex crispus, and Portulaca oleracea were moderate hosts and Ipomoea hederacea var. integriuscula, Xanthium strumarium, Cyperus esculentus, Cynodon dactylon, Paspalum notatum, Eleusine indica, Setaria viridis, and Rumex acetosella were poor hosts for M. incognita. None of the above were good hosts for M. incognita. Tobacco 'PD4' supported large numbers of both nematode species. PMID:19290313

Tedford, E C; Fortnum, B A

1988-10-01

82

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

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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.

Iruthaya Kalaiselvam; Aruna Devaraj

2011-01-01

83

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

Directory of Open Access Journals (Sweden)

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.

M.E El-Hadad; M.I Mustafa; Sh.M Selim; T.S El-Tayeb; A.E.A Mahgoob; Norhan H. Abdel Aziz

2011-01-01

84

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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 uninoculat (more) ed 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.

El-Hadad, M.E; Mustafa, M.I; Selim, Sh.M; El-Tayeb, T.S; Mahgoob, A.E.A; Aziz, Norhan H. Abdel

2011-03-01

85

Rootstocks resistant to Meloidogyne incognita and compatibility of grafting in net melon/ Porta-enxertos resistentes a Meloidogyne incognita e compatibilidade de enxertia de melão rendilhado  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Devido aos poucos estudos realizados com enxertias em melão rendilhado, visando um maior controle de patógenos do solo, este trabalho teve por objetivo avaliar 16 genótipos de cucurbitáceas quanto à resistência a Meloidogyne incognita e a compatibilidade da enxertia do melão rendilhado. Foram avaliados 16 acessos de cucurbitáceas: Benincasa hispida, Bucha, Abóbora 'Jacarezinho', Abóbora 'Menina Brasileira', Moranga 'Exposição', Moranga 'Coroa', Abóbora 'Canh? (more) ?o Seca', Abóbora 'Squash', Mogango 'Enrrugado Verde', Abóbora 'Mini Paulista', Abóbora 'Goianinha', Melancia 'Charleston Gray', Melão 'Rendondo Gaúcho', Melão 'Redondo Amarelo', Pepino 'Caipira HS' e Pepino 'Caipira Rubi', quanto à resistência ao nematóide M. incognita, com base no fator de reprodução (FR), segundo Oostenbrink (1966). Para avaliação da resistência, as mudas foram transplantadas para vasos de cerâmica e foram aplicados 300 ovos ou juvenis de segundo estádio/mL de M. incognita, num total de 10 mL por vaso. Aos 50 dias após o transplantio, as plantas foram removidas dos vasos e realizou-se a avaliação da resistência. Para a compatibilidade entre os porta-enxertos resistentes e enxerto de melão rendilhado, foram realizadas enxertias do tipo garfagem fenda simples, em híbrido comercial de melão rendilhado de grande aceitação comercial e suscetíveil a M. incognita (Bônus N° 2). Os genótipos Bucha, Abóbora 'Goianinha', Abóbora 'Mini-Paulista', Melão 'Redondo Amarelo', Melancia 'Charleston Gray', foram resistentes ao nematóide M. incognita. As melhores compatibilidades ocorreram com os porta-enxertos Melão 'Amarelo', o qual teve 100% de pegamento, seguido da Abóbora 'Mini-Paulista' com 94%. Já Bucha, Melancia 'Charleston Gray' e Abóbora 'Goianinha', tiveram baixas porcentagens de pegamento: 66%, 62% e 50% respectivamente. Abstract in english Due to the few studies about grafting in net melon, in order to obtain better control of soil pathogens, the aim of the present study was to evaluate 16 genotypes of Cucurbitaceae: Benincasa hispida, Luffa cylindrica, pumpkin 'Jacarezinho', pumpkin 'Menina Brasileira', squash 'Exposição', squash 'Coroa', pumpkin 'Canhão Seca', pumpkin 'Squash', pumpkin 'Enrrugado Verde', pumpkin 'Mini Paulista', pumpkin 'Goianinha', watermelon 'Charleston Gray', melon 'Rendondo Gaucho' (more) , melon 'Redondo Amarelo', cucumber 'Caipira HS' and cucumber 'Caipira Rubi', regarding to compatibility of grafting in net melon and resistance to Meloidogyne incognita, based on the reproduction factor (RF), according to Oostenbrink (1966). To assess resistance, the seedlings were transplanted to ceramic pots and inoculated with 300/mL eggs and/or second stage juveniles of M. incognita. At 50 days after transplanting, the plants were removed from the pots and the resistance was evaluated. The compatibility between resistant rootstock and grafts of net melon was determined by performing simple cleft grafting, in a commercial net melon hybrid of great market acceptance and susceptible to M. incognita (Bonus no. 2). The genotypes Luffa cylindrica, pumpkin 'Goianinha', pumpkin 'Mini-Paulista', melon 'Redondo Amarelo', watermelon 'Charleston Gray' are resistant to the nematode M. incognita. The better compatibilities occurred with the rootstocks melon 'Amarelo', which presented 100% of success, followed by pumpkin 'Mini-Paulista' with 94%. On the other hand, Sponge gourd, watermelon 'Charleston Gray' and pumpkin 'Goianinha' showed low graft take percentages of 66%, 62% and 50%, respectively.

Galatti, Francine de Souza; Franco, Alexandre Junqueira; Ito, Letícia Akemi; Charlo, Hamilton de Oliveira; Gaion, Lucas Aparecido; Braz, Leila Trevisan

2013-06-01

86

Screening plants resistant against Meloidogyne incognita and integrated management of plant resources for nematode control  

UK PubMed Central (United Kingdom)

Root-knot nematodes are major diseases of vegetable crops in the greenhouse environment in China. Safe and effective measures are urgently needed to control the diseases. The objectives of this study were to screen appropriate resistant plants intercropping with cucumber or tomato plants and to offer a potential nematode control strategy fitting to the greenhouse environment. The results showed that the castor-oil plant, hot pepper or crown daisy intercropped with cucumber reduced infection by Meloidogyne incognita by 71.54%, 25.90% and 40.42%, respectively. However, intercropping with castor-oil plant or hot pepper inhibited the root growth of cucumber. In addition, tobacco residues management decreased the nematode populations in the soil by 29.38%, but increased the nematode infection load of tomato. Integrated control management of tobacco residues (15 g) with crown daisy reduced tomato root-knot index and densities of nematode populations in the soil by 56.00% and 57.35%, respectively. We conclude that crown daisy is the best selection as an intercropping crop and the management of tobacco residues (15 g) with crown daisy is a better potential nematode control strategy fitting to the greenhouse environment.

Dong Linlin; Huang Chengdong; Huang Li; Li Xiaolin; Zuo Yuanmei

2012-03-01

87

Potential antagonistic effects of nine natural fatty acids against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

Fatty acids, the essential components of life, were widely present in various seed cakes, gutter oil, and other resources. The objective of this study was to evaluate the potential antagonistic effects of nine fatty acids (FAs) against Meloidogyne incognita (root-knot nematodes). The results showed that butyric, caprylic, capric, lauric, myristic, palmitic, and oleic acids significantly reduced M. incognita reproduction, whereas cucumber (Cucumus sativus) biomass was not adversely affected by the tested FAs and was even significantly increased in several fatty acids treatments. All nine tested fatty acids showed apparent inhibitory effects on egg hatching on day 21, especially capric acid with which the hatching rate was reduced to 15.8% as compared to that using sterile distilled water. Caproic, caprylic, capric, lauric, myristic, and palmitic acids caused significantly higher mortality of the second-stage juvenile of M. incognita than the other three FAs, and both caprylic and capric acids resulted in approximately 50% mortality (2000 ?mol/L) after a 24 h exposure. In conclusion, fatty acids showed the nematicidal effect differently, among which capric acid showed a strong nematicidal effect and might be a powerful active substance for integrated M. incognita management. Given the general nematicidal properties of FAs, farmers might utilize waste resources, such as oil seed cake, gutter oil, etc., containing various FAs or use pure FAs for effective M. incognita management.

Zhang WP; Ruan WB; Deng YY; Gao YB

2012-11-01

88

Potential antagonistic effects of nine natural fatty acids against Meloidogyne incognita.  

Science.gov (United States)

Fatty acids, the essential components of life, were widely present in various seed cakes, gutter oil, and other resources. The objective of this study was to evaluate the potential antagonistic effects of nine fatty acids (FAs) against Meloidogyne incognita (root-knot nematodes). The results showed that butyric, caprylic, capric, lauric, myristic, palmitic, and oleic acids significantly reduced M. incognita reproduction, whereas cucumber (Cucumus sativus) biomass was not adversely affected by the tested FAs and was even significantly increased in several fatty acids treatments. All nine tested fatty acids showed apparent inhibitory effects on egg hatching on day 21, especially capric acid with which the hatching rate was reduced to 15.8% as compared to that using sterile distilled water. Caproic, caprylic, capric, lauric, myristic, and palmitic acids caused significantly higher mortality of the second-stage juvenile of M. incognita than the other three FAs, and both caprylic and capric acids resulted in approximately 50% mortality (2000 ?mol/L) after a 24 h exposure. In conclusion, fatty acids showed the nematicidal effect differently, among which capric acid showed a strong nematicidal effect and might be a powerful active substance for integrated M. incognita management. Given the general nematicidal properties of FAs, farmers might utilize waste resources, such as oil seed cake, gutter oil, etc., containing various FAs or use pure FAs for effective M. incognita management. PMID:23121218

Zhang, Wei-pu; Ruan, Wei-bin; Deng, Yun-ying; Gao, Yu-bao

2012-11-09

89

Nematotoxicity of drupacine and a Cephalotaxus alkaloid preparation against the plant-parasitic nematodes Meloidogyne incognita and Bursaphelenchus xylophilus.  

UK PubMed Central (United Kingdom)

BACKGROUND: Species of Cephalotaxus (the plum yews) produce nematotoxic compounds of unknown identity. Consequently, bioassay-guided fractionation was employed to identify the compound(s) in Cephalotaxus fortunei twigs and leaves with activity against plant-parasitic nematodes. RESULTS: A crude alkaloid extract, particularly drupacine, was responsible for much of the nematotoxicity. The ED50 of drupacine for Bursaphelenchus xylophilus was 27.1?µg mL?¹, and for Meloidogyne incognita it was 76.3 µg mL?¹. Immersion of M. incognita eggs in 1.0?mg mL?¹ crude alkaloid extract (the highest tested concentration) reduced hatch by 36%; immersion of second-stage juveniles (J2) resulted in 72-98% immobility. Crude alkaloid extract and drupacine suppressed protease activity in extracts of the microbivorous nematode Panagrellus redivivus by 50% and 80%, respectively. Application of 0.02-0.5?mg mL?¹ crude alkaloid extract to soil with M. incognita inoculum did not significantly reduce pepper plant shoot length or weight, compared with nematode-inoculated, water-treated controls, but the number of eggs and J2 per root system respectively decreased by 69% and 73% at 0.5?mg mL?¹. CONCLUSION: Drupacine and a crude alkaloid extract suppress nematode hatch, activity of mixed life stages, and population numbers on plant roots. This is the first demonstration of nematotoxicity of crude Cephalotaxus alkaloids and drupacine.

Wen Y; Meyer SL; Masler EP; Zhang F; Liao J; Wei X; Chitwood DJ

2013-09-01

90

Virulence development and genetic polymorphism in Meloidogyne incognita (Kofoid & White) Chitwood after prolonged exposure to sublethal concentrations of nematicides and continuous growing of resistant tomato cultivars.  

UK PubMed Central (United Kingdom)

BACKGROUND: The root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood, is an important plant pathogen damaging to tomato. Continuous use of resistant tomato cultivars and nematicides for its effective management might lead to resistance break-up or nematicide failure. Genetic variability and virulence in M. incognita on susceptible Pusa Ruby tomato were analysed by bioassay, esterase and DNA polymorphism after a 5 year weekly exposure to carbofuran, carbosulfan, cadusafos and triazophos at 0.0125, 0.0250 and 0.0500 microg g(-1). Virulence in M. incognita after a 5 year multiplication on resistant tomatoes was assessed. RESULTS: The nematicidal treatments resulted in the development of virulent M. incognita populations. Their invasion potential increased significantly after continuous exposure to low concentrations of the nematicides. Also, growing resistant tomato cultivars for ten successive seasons resulted in a 6.6% increase in the invasion potential. These virulent populations exhibited 1-3 additional esterase and DNA bands compared with untreated populations. CONCLUSION: A 5 year exposure of M. incognita to sublethal concentrations of nematicides or resistant tomato cultivars exerted enough selection pressure to cause genomic alterations for virulence development. Isozyme markers can be used for rapid and precise diagnostics of field populations by advisory services, enabling judicious remedial management decisions.

Meher HC; Gajbhiye VT; Chawla G; Singh G

2009-11-01

91

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 pr (more) eviamente 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. Abstract in english 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 clo (more) nes 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.

Marchese, Aline; Maluf, Wilson Roberto; Gonçalves Neto, Álvaro Carlos; Gonçalves, Ranoel José de Sousa; Gomes, Luiz Antonio Augusto

2010-09-01

92

Uso de agentes microbianos e químico para o controle de Meloidogyne incognita em soja/ Use of microbial and chemical agents to control Meloidogyne incognita in soybean  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Nematoides de galhas constituem importante grupo de patógenos da cultura da soja e o manejo integrado é uma das principais medidas de controle que visam à redução de perdas econômicas. Neste trabalho foi avaliada a eficácia dos fungos Paecilomyces lilacinus (Thom.) Samsom e Pochonia chlamydosporia (Goddard) Zare & Gams (sinonímia Verticillium chlamydosporium), de um produto comercial à base de Bacillus sp. (Nemix) e do nematicida químico Aldicarb no controle de (more) Meloidogyne incognita em soja, variedade M-SOY 6101. O experimento foi realizado em casa-de-vegetação no delineamento experimental de blocos casualizados com nove tratamentos (três produtos biológicos usados no tratamento de sementes com ou sem a aplicação em pós-emergência, Aldicarb aplicado apenas em pós-emergência e duas testemunhas) e quatro repetições. Aldicarb reduziu o número de ovos e de juvenis do nematoide. P. lilacinus foi o mais atuante dos agentes biológicos, favorecendo a manutenção da quantidade de matéria seca da raiz de soja e reduzindo o número de ovos. O produto Nemix e P. chlamydosporia somente tiveram ação efetiva na redução do número de ovos do nematoide. Com base nos resultados, foi possível concluir que o agente químico e os agentes biológicos avaliados neste trabalho tiveram moderada atividade no controle de M. incognita em soja. Abstract in english Root-knot nematodes are considered significant pathogens of soybean crops. The objective of this work was to evaluate the efficacy of two fungi (Paecilomyces lilacinus (Thom.) Samsom and Pochonia chlamydosporia (Goddard) Zare & Gams (syn. Verticillium chlamydosporium), a commercial product based on Bacillus sp. and Aldicarb on the control of Meloidogyne incognita on soybean, cultivar M-SOY 6101. The experimental design was set as randomized blocks with four replications. (more) Nine treatments were evaluated: three biological agents used for seed treatment with and without post-emergence application, Aldicarb on post-emergence only, and two controls. All treatments were inoculated with the nematode, except for a blank control where only water was applied. One control-only treated with the nematode was also included. Aldicarb could reduce the number of eggs and juveniles in the roots. P. lilacinus showed the best performance among the biological control agents, reducing the number of eggs and increasing dry root weight. Nemix, a Bacillus sp. based commercial product and P. chlamydosporia could only reduce significantly the number of eggs of the nematode. In this work, it was possible to conclude that the chemical and biological agents showed a moderate activity in the control of M. incognita in soybean.

Nunes, Henrique Teixeira; Monteiro, Antonio Carlos; Pomela, Alan William Vilela

2010-09-01

93

Inhibitory effects of Teucrium polium L., Artemisia sieberi Besser. and Achillea wilhelmsii C. Koch on Meloidogyne incognita (Kofoid and White) Chitwood (in vitro and under greenhouse conditions)  

Directory of Open Access Journals (Sweden)

Full Text Available During a survey of cultivated fields as well as the greenhouses growing tomatoes (Solanum lycopersicum L.), two species of root-knot nematodes, Meloidogyne javanica and Meloidogyne incognita, were found widely distributed in different agro-ecological zones of Kohgilouyeh and Boyer-Ahmad province, Iran. Nematicidal effects of the water extracts as well as powder of different parts of three plants namely, felty germander (Teucrium polium L.), wormwood (Artemisia sieberi Besser) and yarrow (Achillea wilhelmsii C. Koch), on the M. incognita, were determined under in vitro and greenhouse conditions. Concentrations of extract from plant parts (seed, leave, stem, flower and whole plant except root) tested were at 1, 2 and 4% (w/v) for in vitro experiment and 0.1% and 0.2% (w/w) of leave, stem and whole plant except root for greenhouse experiment. Two second stage juveniles (J2) of M. incognita per gram soil and 200 J2 per milliliter of plants extract were mentioned as inoculums level in in vivo and in vitro conditions respectively. All plant parts and concentrations, significantly (P<0.01) suppressed M. incognita in both in vitro and in vivo conditions in comparison with respective controls (distilled water). Maximum J2 mortality and reduction of gall formation on roots of tomato, number of egg masses, number of eggs and total population of M. incognita were seen in whole plant (mixed) treatment. Results of greenhouse experiments were similar to in vitro ones, in which maximum mortality was recorded with A. wilhelmsii followed by A. sieberi and T. polium. Our recommendation is use of whole plant (except root) extract (2%) and or powder (0.2%) of A. wilhelmsii firstly and A. sieberi secondly in aim to control M. incognita.

Abbas Salahi ARDAKANI; Saadat PARHIZKAR

2012-01-01

94

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

UK PubMed Central (United Kingdom)

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

Faske TR

2013-03-01

95

Efficacy of Fenamiphos Formulations Applied through Irrigation for Control of Meloidogyne incognita on Squash.  

UK PubMed Central (United Kingdom)

Management ofMeloidogyne incognita by chemigation with fenamiphos was studied in an infested field planted to M. incognita-suscepfible yellow summer squash cv. Dixie Hybrid. Fenamiphos (VL 73.1% a.i. manufacturing concentrate in propylene glycol) was mixed with Unitol DSR-90 or used as fenamiphos 3 SC (spray concentrate). Both formulations, applied with 63.5 kl irrigation water per hectare, decreased numbers of M. incognita second-stage juveniles in the soil and root-gall indices, and increased yield of squash compared with the untreated control. There was no benefit achieved by mixing the fenamiphos concentrate with Unitol DSR-90 over the use of fenamiphos 3 SC formulation. Fenamiphos application rates between 3.36 and 6.72 kg a.i./ha could provide control of M. incognita comparable to that obtained with 6.72 kg a.i./ha. Reduced rates of fenamiphos applied with irrigation water used to control plant-parasitic nematodes could reduce the potential for groundwater pollution as well as cost to the grower.

Johnson AW; Young JR

1994-12-01

96

Efficacy of Fenamiphos Formulations Applied through Irrigation for Control of Meloidogyne incognita on Squash  

Science.gov (United States)

Management ofMeloidogyne incognita by chemigation with fenamiphos was studied in an infested field planted to M. incognita-suscepfible yellow summer squash cv. Dixie Hybrid. Fenamiphos (VL 73.1% a.i. manufacturing concentrate in propylene glycol) was mixed with Unitol DSR-90 or used as fenamiphos 3 SC (spray concentrate). Both formulations, applied with 63.5 kl irrigation water per hectare, decreased numbers of M. incognita second-stage juveniles in the soil and root-gall indices, and increased yield of squash compared with the untreated control. There was no benefit achieved by mixing the fenamiphos concentrate with Unitol DSR-90 over the use of fenamiphos 3 SC formulation. Fenamiphos application rates between 3.36 and 6.72 kg a.i./ha could provide control of M. incognita comparable to that obtained with 6.72 kg a.i./ha. Reduced rates of fenamiphos applied with irrigation water used to control plant-parasitic nematodes could reduce the potential for groundwater pollution as well as cost to the grower.

Johnson, A. W.; Young, J. R.

1994-01-01

97

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

Science.gov (United States)

Cucumis melo var. texanus, a wild melon commonly found in the southern United States and two accessions, Burleson Co. and MX 1230, expressed resistance to Meloidogyne incognita in preliminary experiments. To characterize the mechanism of resistance, we evaluated root penetration, post-penetration development, reproduction, and emigration of M. incognita on these two accessions of C. melo var. texanus. Additionally, we evaluated 22 accessions of C. melo var. texanus for their reaction against M. incognita in a greenhouse experiment. Fewer (P ? 0.05) J2 penetrated the root system of C. melo var. texanus accessions (Burleson Co. and MX 1230) and C. metuliferus (PI 482452) (resistant control), 7 days after inoculation (DAI) than in C. melo 'Hales Best Jumbo' (susceptible control). A delayed (P ? 0.05) rate of nematode development was observed at 7, 14, and 21 DAI that contributed to lower (P ? 0.05) egg production on both accessions and C. metuliferus compared with C. melo. Though J2 emigration was observed on all Cucumis genotypes a higher (P ? 0.05) rate of J2 emigration was observed from 3 to 6 DAI on accession Burleson Co. and C. metuliferus than on C. melo. The 22 accessions of C. melo var. texanus varied relative to their reaction to M. incognita with eight supporting similar levels of nematode reproduction to that of C. metuliferus. Cucumis melo var. texanus may be a useful source of resistance against root-knot nematode in melon. PMID:23589661

Faske, T R

2013-03-01

98

Microplot Evaluation of Rootstocks for Control of Meloidogyne incognita on Grafted Tomato, Muskmelon, and Watermelon  

Science.gov (United States)

Microplot experiments were conducted over two years (four growing seasons) to evaluate Meloidogyne incognita resistance in rootstocks used for grafted tomato (Solanum lycopersicum), muskmelon (Cucumis melo), and watermelon (Citrullus lanatus). Three tomato rootstocks; ‘TX301’, ‘Multifort’, and ‘Aloha’, were tested in addition to the nongrafted scion, ‘Florida-47’. Two muskmelon rootstocks; Cucumis metuliferus and ‘Tetsukabuto’ (Cucurbita maxima × Cucurbita moschata) were evaluated with the nongrafted scion ‘Athena’. Two watermelon rootstocks included ‘Emphasis’, a lagenaria-type, and an interspecific squash hybrid ‘StrongTosa’, which were grafted to the scion ‘TriX Palomar’ and planted only in the second year. Microplots were infested with M. incognita eggs in September each year. Tomatoes were planted in September followed by melons in March. In both years of the study, M. incognita juveniles (J2) in soil were similar among all tomato rootstocks, but numbers in roots were higher in the nongrafted Florida 47 than in all grafted rootstocks. In muskmelon only C. metuliferus rootstock reduced galling in nematode infested soil. Tetsukabuto did not reduce numbers of M. incognita J2 in either soil or roots either year. There were no differences in nematode numbers, galling, or plant growth parameters among the watermelon rootstocks tested. The use of resistant rootstocks has great potential for improving nematode control in the absence of soil fumigants.

Kokalis-Burelle, Nancy; Rosskopf, Erin N.

2011-01-01

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COMPORTAMIENTO DE GENOTIPOS DE LA FAMILIA SOLANACEAE FRENTE A Meloidogyne incognita (KOFOID Y WHITE) CHITWOOD1/ BEHAVIOUR OF GENOTYPES FROM SOLANACEA FAMILY IN FRONT TO Meloidogyne incognita (KOFOID Y WHITE) CHITWOOD1  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Los nematodos formadores de agallas (Meloidogyne spp.) constituyen factores limitantes de los rendimientos en la producción de hortalizas en campo abierto y casas de cultivo, donde el tomate (Solanum lycopersicum L. (ex Lycopersicon esculentum Mill)) representa un buen hospedante de estos nematodos. Para manejar las poblaciones de estos organismos, entre otras tácticas se hace uso de genotipos resistentes o se acude al injerto herbáceo para obtener resultados productiv (more) os favorables, resultando necesaria la evaluación de los genotipos a emplear frente a poblaciones nativas, pues se sabe que la resistencia puede ser quebrada por factores tales como la virulencia de la población de Meloidogyne. El objetivo de este estudio fue determinar el comportamiento de líneas, híbridos y variedades de tomate ante una población nativa de M. incognita raza 2, como elemento básico del programa de injerto herbáceo que se desarrolla en Cuba para contar con alternativas al bromuro de metilo. Se inocularon 10 plantas por genotipo, con 1,5 huevos/juveniles.g de suelo-1 y se evaluaron a los 60 días, determinándose el Índice de Agallamiento (IA), Factor de Reproducción (FR) e índice de reproducción (IR). Los cultivares evaluados fueron Lycopersicon peruvianum acc. B6-140; Physalis ixocarpa acc. B6236; Lycopersicon pimpinelifolium acc. Mex 121-A; las variedades/híbridos de S. lycopersicum var. cerasiforme, Vyta, Mariela, Amalia, HC 3880 y HA 3019; el híbrido inter-específico Lycopersicon hirsutum x L. esculentum, Solanum torvum y los híbridos de tomate T-1x14, T-1x15, T-2x16 y LTM. Resultó inmune L. hirsutum x L. esculentum y muy resistentes S. torvum y L. peruvianum. Por su parte, P. ixocarpa se comportó como moderadamente resistente y el resto de los materiales evaluados fueron susceptibles a la población cubana de M. incognita raza 2. Abstract in english The root knot nematodes (Meloidogyne spp.) are limiting factors for yields of vegetables in open areas and crops under shelter conditions, where tomato Solanum lycopersicon L. (ex Lycopersicon esculentum Mill.) represents a very good host for these nematodes. For population management of this pest, resistance and graffing are used, among other tactics, to obtain good productive results, but it is necessary to evaluated the resistance of genotypes to native populations, si (more) nce as it is know resistancemay be broken by factors like virulence of Meloidogyne population. The objective of this study was to determine the behaviour of tomato lines hybrids and varieties to native population of M. incognita race 2, as a basic element for the graffting program being develop in Cuba as an alternative to methyl bromide. Ten plants per genotype were inoculated with 1,5 eggs/juvenils.g of soil-1 and evaluated after 60 days to determined the Root Galling Index (IA), the Reproduction Factor (FR) and the Reproduction Index (IR). The cultivars evaluated were Lycopersicon peruvianum acc. B6-140; Physalis ixocarpa acc. B6236; Lycopersicon pimpinellifolium acc. Mex 121-A; the following varieties/hybrids of Solanum lycopersicum var. ceraciforme, Vyta, Mariela, Amalia, HC 3880 and HA 3019; the interespecific hybrid Lycopersicon hirsutum x L. esculentum, Solanum torvum and the tomato hybrids T-1x14, T-1x15, T-2x16 and LTM. The interespecific hybrid L. hirsutum x L. esculentum was immune, whereas S. torvum and L. peruvianum were very resistant. In other hand, P. ixocarpa behaved as moderately resistant and the rest of genotypes were susceptibles to the Cuban population of M. incognita race 2.

Rodríguez, Mayra G; Gómez, Lucila; González, Farah M; Carrillo, Yudines; Piñón, Maite; Gómez, Olimpia; Casanova, A.S; Álvarez, Martha; Peteira, Belkis

2009-12-01

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Ocorrência de Pratylenchus brachyurus e Meloidogyne incognita na cultura do algodoeiro no Estado do Mato Grosso  

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Full Text Available In a survey carried out in the state of Mato Grosso, Brazil, the lesion nematode, Pratylenchus brachyurus, and the root-knot nematode, Meloidogyne incognita, were found, respectively, in 94% and 3.7% of a total of 623 root and soil samples representing 21,793 ha. No visible aboveground symptoms in cotton (Gossypium hirsutum) plants infected by P. brachyurus were observed, except for typical root lesions. In contrast, plants with M. incognita usually exhibited pronounced symptoms of damage. The high frequency (94%) of P. brachyurus was unexpected and is of concern considering the fact that soybean (Glycine max) and corn (Zea mays), are both susceptible to this nematode and are used in crop rotation programs.

Silva Rosangela A. da; Serrano Mirian A. S.; Gomes Antônio C.; Borges Dárcio C.; Souza Anderson A. de; Asmus Guilherme L.; Inomoto Mário M.

2004-01-01

 
 
 
 
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Host Status of Herbaceous Perennials to Meloidogyne incognita and M. arenaria.  

UK PubMed Central (United Kingdom)

Twenty-two different herbaceous perennials were studied for their reaction to separate inoculations of Meloidogyne arenaria and M. incognita under greenhouse conditions. Perennial taxa that did not develop root-galls following inoculation, and therefore are considered as nonhosts of both nematode species, included species and cultivars of Aethionema, Fragaria, Phlox, and Polygonum. Echinacea, Monarda, and Patrinia developed only a few galls. Root-galls developed on species and cultivars of Achillea, Geranium, Heuchera, Heucherella, Linaria, Nepeta, Nierembergia, Penstemon, and Salvia. There was no difference in the number of root-galls caused by M. arenaria or M. incognita on most plants except for Penstemon cultivars. Plant heights and dry weights varied between species and nematode density.

Walker JT; Melin JB

1998-12-01

102

Evaluation of nematicidal potential in ten indigenous plant species against Meloidogyne incognita  

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Full Text Available In vitro studies on hatching and mortality of second-stage juveniles of Meloidogyne incognita indicated a reduction in hatching and an increase in nematode mortality in treatments with aqueous leaf extracts of seven plant species; Murraya koenigii (curry leaf), Jasminum sambac (Jasmine), Citrus aurantiifolia (sour orange), Rauvolfia serpentina (patal garuda), Zizyphus jujuba (ber), Hibiscus rosa-sinensis (china rose) and Justicia gandurosa [J. gendarussa]. Organic amendment with powdered leaves ofthe plants at 3% w/w in soil infested with M. incognita 3 weeks before transplanting tomato (cv. Pusa Ruby) seedlings reduced nematode infection and increased plant growth in comparison with the control. Although the plant species Gmelina arborea (gambhar), Madhuca latifolia [Madhuca longifolia] (mahula) and Callistemon lanceolatus [Callistemon citrinus] (bottle brush) also possessed nematicidal properties, they adversely affected the growth of tomato plants.

N.N. PADHI and GUNANIDHI BEHERA

2012-01-01

103

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

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

Donggeun Kim; Younghyun Ryu; Hyunro Park; Changseok Huh; Changhwan Bae

2013-01-01

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Resistance induction for Meloidogyne incognita in sugarcane through mineral organic fertilizers  

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Full Text Available The effects of Coda Radimax (CR), Coda Humus-PK (CH) and Coda Vit (CV) on the induction of resistance for Meloidogyne incognita in sugarcane (Saccharum sp.) varieties (RB92579, RB863129, RB867515) through nematode reproduction, plant development and root anatomy analysis, emphasizing the differences of the lignin deposition, and cortex-vascular cylinder proportions were investigated. In 90 days after inoculation with eggs of M. incognita, CR reduced the number of eggs per root system in all the sugarcane varieties; CH and CV reduced eggs density in RB867515; CR increased stalk number in RB92579 and fresh weight of shoots in RB863129 and RB92579; CH increased plant height in RB92579 and fresh weight of shoots in RB92579 and RB867515, CV affected fresh weigh of shoots and roots of RB863129. All the tested compounds did not affect stalk diameter, number and dry weight of shoots. Cross-sections of roots showed no anatomical changes in the M. incognita inoculated tissues.Este estudo investigou, em condições de casa de vegetação, os efeitos de três complexos organo-minerais (Coda Radimax, Coda Humus-PK e Coda Vit) na indução de resistência a Meloidogyne incognita em três variedades: RB92579, RB863129, RB867515 de cana-de-açúcar (Saccharum sp.), considerando-se a reprodução do nematóide, desenvolvimento das plantas e anatomia das raízes, com ênfase a diferenças na deposição de lignina e proporções do córtex e cilindro vascular. As avaliações foram efetuadas 90 dias após a inoculação com 5000 ovos de M. incognita por planta. Em relação à testemunha, Coda Radimax reduziu significativamente o número final de ovos por sistema radicular em todas as variedades. Coda Humus-PK e Coda Vit se mostraram eficientes em diminuir a densidade de ovos em RB867515, mas não em RB863129. Todos os compostos testados não afetaram o diâmetro do colmo, peso da biomassa seca da parte aérea e número de perfilho. Coda Radimax aumentou significativamente o número de colmos em RB92579 e a biomassa fresca da parte aérea em RB863129 e RB92579. Coda Humus-PK aumentou significativamente a altura da planta em RB92579 e a biomassa fresca da parte aérea em RB92579 e RB867515, enquanto Coda Vit afetou, significativamente, a biomassa fresca da parte aérea e raízes de RB863129. Fundamentando-se nas sessões transversais obtidas das raízes de cada variedade de cana observada sob microscópio ótico, não ocorreram modificações anatômicas significativas nos tecidos inoculados com M. incognita em relação aos tecidos sadios.

Andréa Chaves; Elvira Maria Régis Pedrosa; Rejane Magalhães de Mendonça Pimentel; Rildo Sartori Barbosa Coelho; Lílian Margarete Paes Guimarães; Sandra Roberta Vaz Lira Maranhão

2009-01-01

105

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

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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.

Adekunle O.K.; Owa T.E.

2008-01-01

106

Efecto del Vermicompost y Quitina sobre el control de meloidogyne incognita en tomate a nivel de invernadero/ Effect of vermicompost and chitin on the control of Meloidogyne incognita in greenhouse tomato  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Meloidogyne incognita es un nematodo endoparásito sedentario, de penetración total y formador de nódulos radicales; tiene una amplia distribución geográfica y causa pérdidas agrícolas importantes. Recientemente se han utilizado abonos orgánicos y compuestos como la quitina en la supresión de plagas y enfermedades de plantas. El objetivo de esta investigación fue evaluar el efecto de la aplicación de vermicompost de estiércol bovino y su enriquecimiento con qui (more) tina, sobre la infección de M. incognita en plantas de tomate var. Hayslip bajo condiciones de invernadero. Para esto se inocularon las plantas con 5000 unidades de inóculo (huevos+juveniles en segundo estado) por maceta y se compararon con controles que fueron sembrados en suelo sin enmienda orgánica o quitina. La evaluación se llevó a cabo 60 días después y se midió el peso fresco aéreo y radical, peso seco aéreo, población total de nematodos en raíz y suelo, índice de nódulos radicales (INR), índice de masas de huevos (IMH), el factor de reproducción del nematodo (FR) y recuento de grupos funcionales (hongos, bacterias y actinomicetes). La adición al suelo de vermicompost provocó un incremento en las variables peso fresco y seco foliar y peso fresco radical: a mayor porcentaje de vermicompost, mayor incremento; así mismo, la aplicación del vermicompost redujo la cantidad del nematodo en raíz y en suelo. La aplicación de quitina acentuó estos resultados, obteniéndose el menor factor de reproducción de M. Incognita, con un valor de 3,76 para la dosis de 50% vermicompost+quitina, mientras que en el testigo este factor fue de 93,20. La aplicación de quitina como enmienda única solo afectó la población de hongos en el suelo, mientras que la de actinomicetes aumentó en los tratamientos enmendados Abstract in english Meloidogyne incognita is a sedentary endoparasitic nematode, with total penetration and gall-forming; it has a wide geographical distribution and causes significant agricultural losses. Recently, organic fertilizers and compounds such as chitin have been used in the suppression of plant pests and diseases. The aim of this study was to evaluate the effect of applying cattle manure vermicompost, and its enrichment with chitin, on the infection of M. incognita in tomato plan (more) ts var. Hayslip under greenhouse conditions. For this purpose, plants were inoculated with 5000 units of eggs+second stage juveniles per pot and were compared with controls grown in soil without organic amendment or chitin. The evaluation was carried out 60 days afterwards: the shoot and root fresh weight, shoot dry weight, total population in root and soil nematodes, root knot index (INR), rate of egg masses (IMH), the nematode reproduction factor (FR) and functional-groups numbers (fungi, bacteria and actinomycetes) were measured. The addition of vermicompost to soil caused an increase in the variables of shoot fresh and dry weight and fresh root weight: the higher the percentage of vermicompost, the higher the increase; likewise, the application of vermicompost reduced the number of nematodes both in root and soil. The application of chitin accentuated these results by bringing about the lowest reproduction factor of M. incognita, with a value of 3.76 for the dose of vermicompost+50% chitin, whereas in the control this factor had a value of 93.20. The application of chitin as sole amendment affected only the soil fungi population, while the actinomycetes population nincreased in the amended treatments

Castro, Leida; Flores, Lorena; Uribe, Lidieth

2011-12-01

107

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

UK PubMed Central (United Kingdom)

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.

Bellafiore S; Shen Z; Rosso MN; Abad P; Shih P; Briggs SP

2008-10-01

108

Population Dynamics of Meloidogyne incognita, M. arenaria,and Other Nematodes and Crop Yields in Rotations of Cotton, Peanut, and Wheat Under Minimum Tillage  

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Wheat, cotton, and peanut were arranged in three cropping sequences to determine the effects of fenamiphos (6.7 kg a.i./ha) and cropping sequence on nematode population densities and crop yields under conservation tillage and irrigation for 6 years. The cropping sequences included a wheat winter cov...

Johnson, A. W.; Dowler, C. C.; Handoo, Z. A.

109

Meloidogyne incognita and Tomato Response to Thiamine, Ascorbic Acid,L-arginine, and L-glutamic Acid  

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The influence of solutions of ascorbic acid, thiamine, L-arginine, and L-gtutamic acid on egg hatch, juvenile survival, and development and reproduction of Meloidogyne incognita in susceptible and resistant tomatoes was studied. Maximum inhibition of egg hatch occurred at 2,000, 4,000, and 2,000 ppm...

Al-Sayed, A. A.; Thomason, I. J.

110

Molecular cloning and characterisation of a venom allergen AG5-like cDNA from Meloidogyne incognita.  

Science.gov (United States)

RNA fingerprinting was used to identify RNAs that were expressed in parasitic second-stage juveniles of Meloidogyne incognita, but absent from or reduced in preparasitic second-stage juveniles. A cDNA encoding a putative secretory protein was cloned from a M. incognita second-stage juvenile cDNA library by probing with a 0.5kb fragment derived from fingerprinting that was more strongly expressed in parasitic second-stage juveniles. The cDNA, named Mi-msp-1, contained an open reading frame encoding 231 amino acids, with the first 21 amino acids being a putative secretory signal. In Southern blot analysis the Mi-msp-1 hybridised with genomic DNA from M. incognita, Meloidogyne arenaria, Meloidogyne javanica, but not Meloidogyne hapla, Heterodera glycines or Caenorhabditis elegans. In Northern blot analysis a 1kb transcript was detected in both preparasitic and parasitic second-stage juveniles, but not in adult females of M. incognita. Comparing the predicted amino acid sequence with protein databases revealed significant similarity to the venom allergen antigen 5 family of proteins in hymenoptera insects and homologues found in several other nematode species. PMID:10675748

Ding, X; Shields, J; Allen, R; Hussey, R S

2000-01-01

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

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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 h...

Idorenyin A. Udo; Kevin I. Ugwuoke

112

The Histochemical Localization of Several Enzymes of Soybeans Infected with the Root-knot Nematode Meloidogyne incognita acrita  

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The sites of activity of alkaline phosphatase, acid phosphatase, esterase, peroxidase, adenosine triphosphatase, and cytochrome oxidase were demonstrated histochemically in fresh sections of 'Lee' soybeans infected by the root-knot nematode Meloidogyne incognita acrita. Each of the six enzymes was m...

Veech, J. A.; Endo, B. Y.

113

Nematicidal activity of fervenulin isolated from a nematicidal actinomycete, Streptomyces sp. CMU-MH021, on Meloidogyne incognita  

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An isolate of the actinomycete, Streptomyces sp. CMU-MH021 produced secondary metabolites that inhibited egg hatch and increased juvenile mortality of the root-knot nematode Meloidogyne incognita in vitro. 16S rDNA gene sequencing showed that the isolate sequence was 99% identical to Streptomyces ro...

Ruanpanun, Pornthip; Laatsch, Hartmut; Tangchitsomkid, Nuchanart; Lumyong, Saisamorn

114

Effect of Meloidogyne incognita, M. hapla, and M. javanica on the Severity of Fusarium Wilt of Chrysanthemum  

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Rooted cuttings of Chrysanthemum morifolium 'Yellow Delaware' (Fusarium-susceptible) and 'White Iceberg' (Fusarium-resistant) were greenhouse-grown in: (i) non-infested soil; (ii) soil infested with Fusarium oxysporum alone; (iii) soil infested with Meloidogyne incognita, M. javanica or M. hapla; an...

Johnson, A. W.; Littrell, R. H.

115

Effects of Soil Temperatures and Inoculum Levels of Meloidogyne incognita andRhizoctonia solani on Seedling Disease of Cotton  

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Soreshin of cotton was more severe from combined infections of Rhizoctonia solani and Meloidogyne incognita than from either organism alone, when both critical soil temperature and inoculum concentrations were present. Optimum soil temperatures for disease development from combined infections were 1...

Carter, W. W.

116

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

Science.gov (United States)

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...

117

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

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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...

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

118

Potential of sucrose and Pennisetum purpureum cv. Cameroon mulch on the management of Meloidogyne javanica and M. incognita  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Os efeitos da sacarose sobre a motilidade e a infectividade de juvenis de Meloidogyne javanica foram avaliados em condições de laboratório e casa-de-vegetação, usando açúcar mascavo e açúcar cristal. Os resultados indicaram que as soluções de açúcar mascavo e cristal reduziram a motilidade e promoveram alterações morfológicas em juvenis dos nematóides in vitro. A eficiência da sacarose em grânulos e da sacarose em solução, com e sem a cobertura com ma (more) téria vegetal de capim elefante, na redução da reprodução e da população final de M. incognita raça 2 também foi avaliada. A sacarose em grânulos diminuiu os números de galhas e massas de ovos por sistema radicular e também de juvenis no solo. Para o ensaio com sacarose em solução, os melhores resultados para a redução da reprodução foram obtidos com a dose de 300 g de sacarose por litro de solo, aplicada a intervalos de sete dias, juntamente com a cobertura do solo com cobertura de matéria verde de capim-elefante. Abstract in english The effects of sucrose on motility and infectiveness of juveniles of Meloidogyne javanica were evaluated under laboratory and greenhouse conditions, using brown sugar and crystal sugar. Results showed that crystal and brown sugar solutions reduced motility and promoted morphological alterations of juvenile nematodes in vitro. The increasing dosages of sucrose reduced the number of galls and egg masses in tomato root by reducing the number of infective juveniles. The effic (more) iency of granular sucrose, sucrose solution, with and without elephant-grass mulch, in the reduction of reproduction and final population of M. incognita race 2, were also evaluated. Granular sucrose induced decrease on the numbers of galls and eggs masses per root system as well as on juveniles in the soil. For sucrose solution assay, the best results for reproductive reduction were obtained with 300g of granular sucrose per liter of soil, applied at seven days intervals, associated with elephant-grass mulch.

Santiago, Débora Cristina; Homechin, Martin; Montalvan, Ricardo; Krzyzanowski, Alaide Aparecida

2005-11-01

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Potential of sucrose and Pennisetum purpureum cv. Cameroon mulch on the management of Meloidogyne javanica and M. incognita  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of sucrose on motility and infectiveness of juveniles of Meloidogyne javanica were evaluated under laboratory and greenhouse conditions, using brown sugar and crystal sugar. Results showed that crystal and brown sugar solutions reduced motility and promoted morphological alterations of juvenile nematodes in vitro. The increasing dosages of sucrose reduced the number of galls and egg masses in tomato root by reducing the number of infective juveniles. The efficiency of granular sucrose, sucrose solution, with and without elephant-grass mulch, in the reduction of reproduction and final population of M. incognita race 2, were also evaluated. Granular sucrose induced decrease on the numbers of galls and eggs masses per root system as well as on juveniles in the soil. For sucrose solution assay, the best results for reproductive reduction were obtained with 300g of granular sucrose per liter of soil, applied at seven days intervals, associated with elephant-grass mulch.Os efeitos da sacarose sobre a motilidade e a infectividade de juvenis de Meloidogyne javanica foram avaliados em condições de laboratório e casa-de-vegetação, usando açúcar mascavo e açúcar cristal. Os resultados indicaram que as soluções de açúcar mascavo e cristal reduziram a motilidade e promoveram alterações morfológicas em juvenis dos nematóides in vitro. A eficiência da sacarose em grânulos e da sacarose em solução, com e sem a cobertura com matéria vegetal de capim elefante, na redução da reprodução e da população final de M. incognita raça 2 também foi avaliada. A sacarose em grânulos diminuiu os números de galhas e massas de ovos por sistema radicular e também de juvenis no solo. Para o ensaio com sacarose em solução, os melhores resultados para a redução da reprodução foram obtidos com a dose de 300 g de sacarose por litro de solo, aplicada a intervalos de sete dias, juntamente com a cobertura do solo com cobertura de matéria verde de capim-elefante.

Débora Cristina Santiago; Martin Homechin; Ricardo Montalvan; Alaide Aparecida Krzyzanowski

2005-01-01

120

Fosthiazate Controls Meloidogyne arenaria and M. incognita in Flue-Cured Tobacco.  

Science.gov (United States)

The nematicide fosthiazate was evaluated over a 3-year period for management of Meloidogyne incognita race 3 (site 1) and M. arenaria race 2 (site 2) in flue-cured tobacco. Fosthiazate was applied broadcast and incorporated at rates ranging from 22 to 88 g a.i./100 m(2), and compared with the nematicides fenamiphos (67 g a.i./100 m(2)), 1,3-D (56.1 L/ha, 670 ml/100-m row), and an untreated control. Root-gall indices and leaf yields were averaged over the 3-year period. Root galling was negatively correlated in a linear relationship with fosthiazate application rate at sites 1 and 2. Leaf yields were positively correlated with fosthiazate application rate at site 1 and could be described by a quadratic equation. Leaf yields were greater at 33 and 88 g a.i./100 m(2) application rates (site 2) than the untreated control. Leaf yields in fosthiazate (88 g a.i./100 m(2))-treated plots infested with M. incognita or M. arenaria were not different from plots fumigated with 1,3-D. Plants in plots with fosthiazate applied in a row band (1993) had a lower root-gall index than those in plots with the same rate of fosthiazate applied broadcast. Fosthiazate may provide an alternative to fumigation for control of M. incognita and M. arenaria. PMID:19270938

Pullen, M P; Fortnum, B A

1999-12-01

 
 
 
 
121

Fosthiazate Controls Meloidogyne arenaria and M. incognita in Flue-Cured Tobacco.  

UK PubMed Central (United Kingdom)

The nematicide fosthiazate was evaluated over a 3-year period for management of Meloidogyne incognita race 3 (site 1) and M. arenaria race 2 (site 2) in flue-cured tobacco. Fosthiazate was applied broadcast and incorporated at rates ranging from 22 to 88 g a.i./100 m(2), and compared with the nematicides fenamiphos (67 g a.i./100 m(2)), 1,3-D (56.1 L/ha, 670 ml/100-m row), and an untreated control. Root-gall indices and leaf yields were averaged over the 3-year period. Root galling was negatively correlated in a linear relationship with fosthiazate application rate at sites 1 and 2. Leaf yields were positively correlated with fosthiazate application rate at site 1 and could be described by a quadratic equation. Leaf yields were greater at 33 and 88 g a.i./100 m(2) application rates (site 2) than the untreated control. Leaf yields in fosthiazate (88 g a.i./100 m(2))-treated plots infested with M. incognita or M. arenaria were not different from plots fumigated with 1,3-D. Plants in plots with fosthiazate applied in a row band (1993) had a lower root-gall index than those in plots with the same rate of fosthiazate applied broadcast. Fosthiazate may provide an alternative to fumigation for control of M. incognita and M. arenaria.

Pullen MP; Fortnum BA

1999-12-01

122

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

UK PubMed Central (United Kingdom)

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

Tedford EC; Fortnum BA

1988-10-01

123

In vitro studies of antagonistic fungi against the root-knot nematode, Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

The present study was carried out in vitro to determine the efficacy of indigenous fungi isolated from egg masses of root-knot nematode, Meloidogyne incognita on egg parasitism, egg hatching, mobility and mortality against root-knot nematode, M. incognita. The tested fungi were Acremonium strictum, Aspergillus terreus, A. nidulans, A. niger, Chetomium aubense, Chladosporium oxysporum, Fusarium chlamydosporium, F. dimarum, F. oxysporum, F. solani, Paecilomyces lilacinus, Pochonia chlamydosporia, Trichoderma viride and T. harzianum. All tested fungi showed varied effects against the nematodes. Culture filtrates of A. strictum was very effective against the nematode in regards to egg parasitism (53%), egg hatching inhibition (86%) and mortality (68%) compared to controls. A. strictum was found to have an advantage over P. lilacinus, P. chlamydosporia, T. viride and T. harzianum in that it caused greater mortality of the second stage juveniles (J2). A. terreus did not show egg parasitism but was found to be highly toxic against second stage juveniles (J2) causing high mortality (around 68%). Thus, A. strictum and A. terreus showed good biocontrol potential against root-knot nematode, M. incognita under in vitro conditions.

Singh Satyandra; Mathur Nita

2010-01-01

124

Chemical composition and nematicidal activity of essential oil of Agastache rugosa against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

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 ?g/mL. The components eugenol (LC50 = 66.6 ?g/mL) and methyleugenol (LC50 = 89.4 ?g/mL) exhibited stronger nematicidal activity against M. incognita (LC50 = 185.9 ?g/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.

Li HQ; Liu QZ; Liu ZL; Du SS; Deng ZW

2013-01-01

125

Nematicidal Activity of 2-Thiophenecarboxaldehyde and Methylisothiocyanate from Caper (Capparis spinosa) against Meloidogyne incognita.  

Science.gov (United States)

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 EC(50) 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 (EC(50) = 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

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

2012-07-20

126

Nematicidal Activity of 2-Thiophenecarboxaldehyde and Methylisothiocyanate from Caper (Capparis spinosa) against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

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 EC(50) 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 (EC(50) = 7.9 ± 1.6, and 14.1 ± 1.9 mg/L respectively) for M. incognita. Moreover, 2-thiophenecarboxaldehyde showed a strong fumigant activity.

Caboni P; Sarais G; Aissani N; Tocco G; Sasanelli N; Liori B; Carta A; Angioni A

2012-07-01

127

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

Directory of Open Access Journals (Sweden)

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 ?g/mL. The components eugenol (LC50 = 66.6 ?g/mL) and methyleugenol (LC50 = 89.4 ?g/mL) exhibited stronger nematicidal activity against M. incognita (LC50 = 185.9 ?g/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.

He Qin Li; Qi Zhi Liu; Zhi Long Liu; Shu Shan Du; Zhi Wei Deng

2013-01-01

128

Nematicidal activity of chaetoglobosin A poduced by Chaetomium globosum NK102 against Meloidogyne incognita.  

Science.gov (United States)

The nematicidal activity of Chaetomium globosum NK102, culture filtrates, and chaetoglobosin A (ChA) purified by HPLC was evaluated on Meloidogyne incognita . The results showed that C. globosum NK102 significantly repelled second-stage juveniles (J2s). Both filtrates and ChA demonstrated strong adverse effects on J2 mortality with 99.8% at 300 ?g ChA/mL (LC(50) = 77.0 ?g/mL) at 72 h. ChA and filtrates did not affect egg hatch until 72 h of exposure. All filtrate treatments inhibited the J2 penetration even in 12.5% dilution treatment. Similarly, ChA (300 and 30 ?g/mL) showed a significant inhibitory effect on J2 penetration. The number of eggs per plant was significantly reduced in the treatment of 30 mg ChA/kg soil by 63% relative to control plants, indicating the apparent negative effect on reproduction of M. incognita. The study demonstrated the nematicidal activity of ChA and suggested that it could be a potential biocontrol agent for integrated management of M. incognita. PMID:23214998

Hu, Yang; Zhang, Weipu; Zhang, Ping; Ruan, Weibin; Zhu, Xudong

2012-12-24

129

Nematicidal activity of chaetoglobosin A poduced by Chaetomium globosum NK102 against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

The nematicidal activity of Chaetomium globosum NK102, culture filtrates, and chaetoglobosin A (ChA) purified by HPLC was evaluated on Meloidogyne incognita . The results showed that C. globosum NK102 significantly repelled second-stage juveniles (J2s). Both filtrates and ChA demonstrated strong adverse effects on J2 mortality with 99.8% at 300 ?g ChA/mL (LC(50) = 77.0 ?g/mL) at 72 h. ChA and filtrates did not affect egg hatch until 72 h of exposure. All filtrate treatments inhibited the J2 penetration even in 12.5% dilution treatment. Similarly, ChA (300 and 30 ?g/mL) showed a significant inhibitory effect on J2 penetration. The number of eggs per plant was significantly reduced in the treatment of 30 mg ChA/kg soil by 63% relative to control plants, indicating the apparent negative effect on reproduction of M. incognita. The study demonstrated the nematicidal activity of ChA and suggested that it could be a potential biocontrol agent for integrated management of M. incognita.

Hu Y; Zhang W; Zhang P; Ruan W; Zhu X

2013-01-01

130

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

Science.gov (United States)

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 ...

131

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

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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.

Mohamed A. Elwakil; Z.A. Mohamed; A.G.El-Sherif

2003-01-01

132

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A influência de Meloidogyne incognita e M paranaensis no desenvolvimento de mudas de erva-mate, foi avaliada em casa-de-vegetação e laboratório. O delineamento experimental foi inteiramente casualizado, com 10 repetições, sendo cada parcela formada de 1 plântula de erva-mate/vaso, inoculada com 5000 ovos de M. incognita raças 1, 2, 3, 4 e M. paranaensis. Aos 120 dias, observou-se que a erva-mate, além de boa hospedeira destes nematóides, permitiu-lhes completar (more) seu ciclo vital. O desenvolvimento das plantas foi significativamente afetado pelas raças 1 e 2 de M. incognita.; os pesos de matéria seca e fresca da parte aérea sofreram alterações conforme o tratamento. Não houve alteração no peso fresco de raízes e o número de ovos por raízes foi semelhante para as raças 1 e 2 de M. incognita, sendo, porém, mais elevado nos demais tratamentos. O fator de reprodução foi superior a 1 em todos os tratamentos, indicando a susceptibilidade da erva-mate a estes agentes. Abstract in english 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 finis (more) h 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.

Santiago, Débora Cristina; Krzyzanowski, Alaíde Aparecida; Homechin, Martin

2000-01-01

133

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

Directory of Open Access Journals (Sweden)

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 influência de Meloidogyne incognita e M paranaensis no desenvolvimento de mudas de erva-mate, foi avaliada em casa-de-vegetação e laboratório. O delineamento experimental foi inteiramente casualizado, com 10 repetições, sendo cada parcela formada de 1 plântula de erva-mate/vaso, inoculada com 5000 ovos de M. incognita raças 1, 2, 3, 4 e M. paranaensis. Aos 120 dias, observou-se que a erva-mate, além de boa hospedeira destes nematóides, permitiu-lhes completar seu ciclo vital. O desenvolvimento das plantas foi significativamente afetado pelas raças 1 e 2 de M. incognita.; os pesos de matéria seca e fresca da parte aérea sofreram alterações conforme o tratamento. Não houve alteração no peso fresco de raízes e o número de ovos por raízes foi semelhante para as raças 1 e 2 de M. incognita, sendo, porém, mais elevado nos demais tratamentos. O fator de reprodução foi superior a 1 em todos os tratamentos, indicando a susceptibilidade da erva-mate a estes agentes.

Débora Cristina Santiago; Alaíde Aparecida Krzyzanowski; Martin Homechin

2000-01-01

134

Efeitos da temperatura sobre a atividade de fungos no controle biológico de Meloidogyne javanica E M. incognita raça 3 Effect of soil warming on the biological control of Meloidogyne javanica and M. incognita race 3  

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Full Text Available O efeito de Arthrobotrys conoides, Duddingtonia flagrans, Paecilomyces lilacinus, Paecilomyces variotii, Monacrosporium doedycoides e um isolado de rizobactéria na reprodução e crescimento populacional de Meloidogyne javanica e M. incognita raça 3 em tomateiro Santa Clara, suscetível à Meloidogyne spp., foi estudado em três ambientes distintos: 1) casa-de-vegetação sem controle de temperatura; 2) sala climatizada com temperatura do ar constante a 24ºC; 3) em banho-maria com temperatura do solo mantida em 29-30ºC, colocado na mesma sala climatizada caracterizada anteriormente. Maior crescimento populacional de M. javanica e de M. incognita raça 3 ocorreu em solo aquecido, comparado com aquela em casa-de-vegetação e sala climatizada, e o número de galhas causado por M. javanica e M. incognita raça 3 foi maior em solo aquecido e em sala climatizada do que em casa-de-vegetação. Em solo aquecido e em sala climatizada, A. conoides e a rizobactéria reduziram (PThe effects of Arthrobotrys conoides, Duddingtonia flagrans, Paecilomyces lilacinus, Paecilomyces variotii, Monacrosporium doedycoides and an isolate of rhizobacterium on reproductivity of Meloidogyne javanica and M. incognita race 3 on Santa Clara tomato plants, susceptible to Meloidogyne spp., were studied in three different environments: 1) greenhouse without temperature control; 2) room with air temperature controlled at 24ºC; 3) watherbath with soil temperature controlled at 29-30ºC, placed in the room with the temperature controlled at 24ºC. Greatest M. javanica and M. incognita race 3 reproductivity occurred in waterbath warmed soil than in greenhouse and temperature controlled room. Galls number caused by M. javanica and M. incognita race 3 was greater in waterbath warmed soil and temperature controlled room than in greenhouse. In waterbath warmed soil and in temperature controlled room, A. conoides and rhizobacterium reduced (P< 0,05) the galls number of M. incognita race 3 compared to control. A. conoides also reduced the eggs number of M. incognita race 3 compared to control in waterbath warmed soil. In greenhouse, all antagonistics used reduced the eggs number compared to control.

Fábio R. Alves; Vicente Paulo Campos

2003-01-01

135

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

UK PubMed Central (United Kingdom)

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.

Oliveira JT; Andrade NC; Martins-Miranda AS; Soares AA; Gondim DM; Araújo-Filho JH; Freire-Filho FR; Vasconcelos IM

2012-02-01

136

Reação de genótipos de milho ao parasitismo de Meloidogyne incognita raça 1 e a M. paranaensis = Reaction of corn genotypes to parasitism from Meloidogyne incognita breed 1 and M. paranaensis  

Directory of Open Access Journals (Sweden)

Full Text Available O uso de híbridos e genótipos de milho resistentes aos nematóides formadores de galhas em sistemas de rotação de culturas mantém sua população em níveis baixos, diminuindo as perdas e possibilitando, posteriormente, o uso de genótipos mais suscetíveis. No presentetrabalho, foi avaliada a resistência de 18 genótipos de milho ao parasitismo de M. paranaensis e a M. incognita raça 1 em casa-de-vegetação. As plantas foram inoculadas com 5.000 ovos e eventuaisjuvenis dos respectivos nematóides. O delineamento utilizado foi inteiramente ao acaso, com dez repetições para cada tratamento com os nematóides e cinco repetições para a testemunha sem inoculação. Também foi realizada a técnica de coloração das raízes com fucsina ácida, pelo método de Byrd et al. (1972). Sessenta dias após a inoculação, os sistemas radiculares foram coletados, lavados e avaliados quanto à penetração, produção de ovos e estimativa do Fator de Reprodução (FR). Os resultados mostraram que, para M. paranaensis, o FR variou de 0,01 a 0,08;para M. incognita, a variação foi de 0,01 a 0,03, mostrando que todos os genótipos se comportaram como resistentes, apresentando FR The use of corn hybrids and genotypes resistant to root-knot nematodes in crop rotation systems reduce the population of nematodes, preventing losses and allowing for the use of more susceptible genotypes. In this study, the resistance of eighteen hybrids of corn to parasitism of Meloidogyne paranaensis and M. incognita breed 1 were evaluated in a greenhouse. The plants were inoculated with 5,000 eggs and possible juveniles of each nematode in a completely randomized design, using ten replicates for eachtreatment with nematodes, and five replicates for the treatment without inoculation (control). The root staining technique using acid fuchsin was also applied, according to Byrd et al. (1972). Sixty days after the inoculation, the roots systems were collected, washedand evaluated for penetration, egg production and estimated reproduction factor (RF). The results showed that, for M.paranaensis, the RF varied from 0.01 to 0.08, while for M. incognita the variation was from 0.01 to 0.03, showing that all corn genotypes were resistant,presenting a RF < 1.

Ricardo Michael Levy; Martin Homechin; Débora Cristina Santiago; Marina Capparelli Cadioli; Fernando César Baida

2009-01-01

137

Reação de genótipos de milho ao parasitismo de Meloidogyne incognita raça 1 e a M. paranaensis/ Reaction of corn genotypes to parasitism from Meloidogyne incognita breed 1and M. paranaensis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O uso de híbridos e genótipos de milho resistentes aos nematóides formadores de galhas em sistemas de rotação de culturas mantém sua população em níveis baixos, diminuindo as perdas e possibilitando, posteriormente, o uso de genótipos mais suscetíveis. No presente trabalho, foi avaliada a resistência de 18 genótipos de milho ao parasitismo de M. paranaensis e a M. incognita raça 1 em casa-de-vegetação. As plantas foram inoculadas com 5.000 ovos e eventuais (more) juvenis dos respectivos nematóides. O delineamento utilizado foi inteiramente ao acaso, com dez repetições para cada tratamento com os nematóides e cinco repetições para a testemunha sem inoculação. Também foi realizada a técnica de coloração das raízes com fucsina ácida, pelo método de Byrd et al. (1972). Sessenta dias após a inoculação, os sistemas radiculares foram coletados, lavados e avaliados quanto à penetração, produção de ovos e estimativa do Fator de Reprodução (FR). Os resultados mostraram que, para M. paranaensis, o FR variou de 0,01 a 0,08; para M. incognita, a variação foi de 0,01 a 0,03, mostrando que todos os genótipos se comportaram como resistentes, apresentando FR Abstract in english The use of corn hybrids and genotypes resistant to root-knot nematodes in crop rotation systems reduce the population of nematodes, preventing losses and allowing for the use of more susceptible genotypes. In this study, the resistance of eighteen hybrids of corn to parasitism of Meloidogyne paranaensis and M. incognita breed 1 were evaluated in a greenhouse. The plants were inoculated with 5,000 eggs and possible juveniles of each nematode in a completely randomized desi (more) gn, using ten replicates for each treatment with nematodes, and five replicates for the treatment without inoculation (control). The root staining technique using acid fuchsin was also applied, according to Byrd et al. (1972). Sixty days after the inoculation, the roots systems were collected, washed and evaluated for penetration, egg production and estimated reproduction factor (RF). The results showed that, for M. paranaensis, the RF varied from 0.01 to 0.08, while for M. incognita the variation was from 0.01 to 0.03, showing that all corn genotypes were resistant, presenting a RF

Levy, Ricardo Michael; Homechin, Martin; Santiago, Débora Cristina; Cadioli, Marina Capparelli; Baida, Fernando César

2009-12-01

138

Registro da ocorrência de Meloidogyne incognita no porta-enxerto 'IAC 766-Campinas' no estado de Pernambuco e reação de porta-enxertos e de cultivares copa de videira a Meloidogyne spp. Meloidogyne incognita report on 'IAC 766-Campinas' rootstock in the state of Pernambuco and reaction of grape rootstocks and cultivars to Meloidogyne spp.  

Directory of Open Access Journals (Sweden)

Full Text Available Relata-se a ocorrência 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 raízes com numerosas galhas em meio ao cultivo de feijão-de-porco (Canavalia ensiformis), também atacado pelo nematoide. Com o objetivo de avaliar a resistência de quatro porta-enxertos tropicais, oito de clima temperado, e as cultivares Niágara Rosada e Chardonnay quanto à reação a M. incognita e M. arenaria, em casa de vegetação, 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 inoculação, cada planta foi avaliada quanto ao número de galhas e número de ovos por planta, determinando-se, a seguir, o fator de reprodução de cada espécie do nematoide (FR=população inicial/população 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 suscetíveis às duas espécies de Meloidogyne testadas.The occurrence of root-knot nematode Meloidogyne incognita (Est. I2) is reported in grapevine in Petrolina municipality, State of Pernambuco. Grape plants of Festival cultivar grafted on the 'IAC 766 - Campinas' rootstock attacked by M. incognita exhibited symptoms of less vigorous growth, yellowing and sparse leaves and multiple galls in the root system in an area cultivated with jack-bean (Canavalia ensiformis) also infected by the same nematode. In order to evaluate resistance of four tropical rootstocks, eight temperate and two cultivars Chardonnay and Niagara Rosada in reaction to M. incognita and M. arenaria, this study was carried out. Seedlings of the investigated grapevine genotypes were maintained in pots with sterilized soil and subsequently inoculated with 10,000 eggs + J2 of M. incognita or M. arenaria per plant in a six replicate design. Eight months after nematode inoculation, each plant was evaluated by counting gall and eggs. The final number of eggs (FP) of each Meloidogyne specie was calculated and the reproductive factor (RF = FP/IP), determined. Among the tested rootstocks, 'Harmony', 'Salt Creek', '1103 Paulsen', 'IAC 572-Jales', 'IAC 313-Tropical', 'K5BB Kober', 'SO4' , were resistant (RF1.00) to M. arenaria. In contrast, both tested grapevine scion cultivars were susceptible to the investigated Meloidogyne species.

Lúcia Somavilla; Cesar Bauer Gomes; Vera Maria Quecini

2012-01-01

139

Histopathology of Root-knot Nematode (Meloidogyne incognita) Infection on White Yam (Dioscorea rotundata) Tubers.  

UK PubMed Central (United Kingdom)

White yam tissues naturally and artificially infected with root-knot nematodes were fixed, sectioned, and examined with a microscope. Infective second-stage juveniles of Meloidogyne incognita penetrated and moved intercellularly within the tuber. Feeding sites were always in the ground tissue layer where the vascular tissues are distributed in the tubers. Giant cells were always associated with xylem tissue. They were thin walled with dense cytoplasm and multinucleated. The nuclei of the giant cells were only half the size of those found in roots of infected tomato plants. Normal nematode growth and development followed giant cell formation. Females deposited eggs into a gelatinous egg mass within the tuber, and a necrotic ring formed around the female after eggs had been produced. Second-stage juveniles hatched, migrated, and re-infected other areas of the tuber. No males were observed from the tuber.

Fawole B

1988-01-01

140

Isolation of nematicidal triterpenoid saponins from Pulsatilla koreana root and their activities against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

Pulsatilla koreana, a species endemic to Korea, is an important herb used in traditional medicine to treat amoebic dysentery and malaria. In the present study, 23 oleanane-type triterpenoid saponins 1-23 and eight lupane-type triterpenoid saponins 24-31 were isolated from the roots of P. koreana. Their structures were elucidated on the basis of spectroscopic data. The methanol extract and isolated compounds were next assessed for nematicidal activity against the root-knot nematode (Meloidogyne incognita). The methanol extract showed strong nematicidal activity after 48 h, with a LC?? value of 92.8 ?g/mL. Compounds 2, 5, 9, 20, and 21 showed significant effects, with LC?? values ranging from 70.1 to 94.7 ?g/mL after 48 h. These results suggest that triterpenoid saponins from P. koreana should be explored as potential natural nematicides for developing new agents to control root-knot nematode disease.

Li W; Sun YN; Yan XT; Yang SY; Lee SJ; Byun HJ; Moon CS; Han BS; Kim YH

2013-01-01

 
 
 
 
141

Isolation of nematicidal triterpenoid saponins from Pulsatilla koreana root and their activities against Meloidogyne incognita.  

Science.gov (United States)

Pulsatilla koreana, a species endemic to Korea, is an important herb used in traditional medicine to treat amoebic dysentery and malaria. In the present study, 23 oleanane-type triterpenoid saponins 1-23 and eight lupane-type triterpenoid saponins 24-31 were isolated from the roots of P. koreana. Their structures were elucidated on the basis of spectroscopic data. The methanol extract and isolated compounds were next assessed for nematicidal activity against the root-knot nematode (Meloidogyne incognita). The methanol extract showed strong nematicidal activity after 48 h, with a LC?? value of 92.8 ?g/mL. Compounds 2, 5, 9, 20, and 21 showed significant effects, with LC?? values ranging from 70.1 to 94.7 ?g/mL after 48 h. These results suggest that triterpenoid saponins from P. koreana should be explored as potential natural nematicides for developing new agents to control root-knot nematode disease. PMID:23698044

Li, Wei; Sun, Ya Nan; Yan, Xi Tao; Yang, Seo Young; Lee, Suk Jun; Byun, Hyo Jeung; Moon, Chang Sup; Han, Byung Soo; Kim, Young Ho

2013-05-08

142

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

International Nuclear Information System (INIS)

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.

2008-01-01

143

Use of Cucumis metuliferus as a Rootstock for Melon to Manage Meloidogyne incognita.  

Science.gov (United States)

Root-knot nematode-susceptible melons (Cantaloupe) were grown in pots with varying levels of Meloidogyne incognita and were compared to susceptible melons that were grafted onto Cucumis metuliferus or Cucurbita moschata rootstocks. In addition, the effect of using melons as transplants in nematode-infested soil was compared to direct seeding of melons in nematode-infested soil. There were no differences in shoot or root weight, or severity of root galling between transplanted and direct-seeded non-grafted susceptible melon in nematode-infested soil. Susceptible melon grafted on C. moschata rootstocks had lower root gall ratings and, at high nematode densities, higher shoot weights than non-grafted susceptible melons. However, final nematode levels were not lower on the grafted than on the non-grafted plants, and it was therefore concluded that grafting susceptible melon on to C. moschata rootstock made the plants tolerant, but not resistant, to the nematodes. Grafting susceptible melons on C. metuliferus rootstocks also reduced levels of root galling, prevented shoot weight losses, and resulted in significantly lower nematode levels at harvest. Thus, C. metuliferus may be used as a rootstock for melon to prevent both growth reduction and a strong nematode buildup in M. incognita-infested soil. PMID:19262873

Sigüenza, Concepcion; Schochow, Martin; Turini, Tom; Ploeg, Antoon

2005-09-01

144

RNA interference of dual oxidase in the plant nematode Meloidogyne incognita.  

Science.gov (United States)

RNA interference (RNAi) is a powerful tool for the analysis of gene function in model organisms such as the nematode Caenorhabditis elegans. Recent demonstrations of RNAi in plant parasitic nematodes provide a stimulus to explore the potential of using RNAi to investigate disruption of gene function in Meloidogyne incognita, one of the most important nematode pests of global agriculture. We have used RNAi to examine the importance of dual oxidases (peroxidase and NADPH oxidase), a class of enzyme associated with extracellular matrix cross-linking in C. elegans. RNAi uptake by M. incognita juveniles is highly efficient. In planta infection data show that a single 4-h preinfection treatment with double-stranded RNA derived from the peroxidase region of a dual oxidase gene has effects on gene expression that are phenotypically observable 35 days postinfection. This RNAi effect results in a reduction in egg numbers at 35 days of up to 70%. The in vitro feeding strategy provides a powerful tool for identifying functionally important genes, including those that are potential targets for the development of new agrochemicals or transgenic resistance strategies. PMID:16255249

Bakhetia, Manjula; Charlton, Wayne; Atkinson, Howard J; McPherson, Michael J

2005-10-01

145

RNA interference of dual oxidase in the plant nematode Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

RNA interference (RNAi) is a powerful tool for the analysis of gene function in model organisms such as the nematode Caenorhabditis elegans. Recent demonstrations of RNAi in plant parasitic nematodes provide a stimulus to explore the potential of using RNAi to investigate disruption of gene function in Meloidogyne incognita, one of the most important nematode pests of global agriculture. We have used RNAi to examine the importance of dual oxidases (peroxidase and NADPH oxidase), a class of enzyme associated with extracellular matrix cross-linking in C. elegans. RNAi uptake by M. incognita juveniles is highly efficient. In planta infection data show that a single 4-h preinfection treatment with double-stranded RNA derived from the peroxidase region of a dual oxidase gene has effects on gene expression that are phenotypically observable 35 days postinfection. This RNAi effect results in a reduction in egg numbers at 35 days of up to 70%. The in vitro feeding strategy provides a powerful tool for identifying functionally important genes, including those that are potential targets for the development of new agrochemicals or transgenic resistance strategies.

Bakhetia M; Charlton W; Atkinson HJ; McPherson MJ

2005-10-01

146

Potent nematicidal activity of phthalaldehyde, salicylaldehyde, and cinnamic aldehyde against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

The nematicidal activity of selected aromatic aldehydes was tested against the root knot nematode Meloidogyne incognita. The most active aldehyde was phthalaldehyde (1) with an EC(50) value of 11 ± 6 mg/L followed by salicylaldehyde (2) and cinnamic aldehyde (3) with EC(50) values of 11 ± 1 and 12 ± 5 mg/L, respectively. On the other hand, structurally related aldehydes such as 2-methoxybenzaldehyde (21), 3,4-dimethoxybenzaldehyde, and vanillin (23) were not active at the concentration of 1000 mg/L. By liquid chromatography-mass spectrometry the reactivity of tested aldehydes against a synthetic peptide resembling the nematode cuticle was characterized. At the test concentration of 1 mM, the main adduct formation was observed for 3,4-dihydroxybenzaldehyde (22), 2-methoxybenzaldehyde (21), and 3,4-dimethoxybenzaldehyde. Considering that 2-methoxybenzaldehyde (21) and 3,4-dimethoxybenzaldehyde were not active against M. incognita in in vitro experiments led us to hypothesize a different mechanism of action rather than an effect on the external cuticle modification of nematodes. When the toxicity of the V-ATPase inhibitor pyocyanin (10) was tested against M. incognita J2 nematodes, an EC(50) at 24 h of 72 ± 25 mg/L was found. The redox-active compounds such as phthalaldehyde (1) and salicylaldehyde (2) may share a common mode of action inhibiting nematode V-ATPase enzyme. The results of this investigation reveal that aromatic redox-active aldehydes can be considered as potent nematicides, and further investigation is needed to completely clarify their mode of action.

Caboni P; Aissani N; Cabras T; Falqui A; Marotta R; Liori B; Ntalli N; Sarais G; Sasanelli N; Tocco G

2013-02-01

147

Potent nematicidal activity of phthalaldehyde, salicylaldehyde, and cinnamic aldehyde against Meloidogyne incognita.  

Science.gov (United States)

The nematicidal activity of selected aromatic aldehydes was tested against the root knot nematode Meloidogyne incognita. The most active aldehyde was phthalaldehyde (1) with an EC(50) value of 11 ± 6 mg/L followed by salicylaldehyde (2) and cinnamic aldehyde (3) with EC(50) values of 11 ± 1 and 12 ± 5 mg/L, respectively. On the other hand, structurally related aldehydes such as 2-methoxybenzaldehyde (21), 3,4-dimethoxybenzaldehyde, and vanillin (23) were not active at the concentration of 1000 mg/L. By liquid chromatography-mass spectrometry the reactivity of tested aldehydes against a synthetic peptide resembling the nematode cuticle was characterized. At the test concentration of 1 mM, the main adduct formation was observed for 3,4-dihydroxybenzaldehyde (22), 2-methoxybenzaldehyde (21), and 3,4-dimethoxybenzaldehyde. Considering that 2-methoxybenzaldehyde (21) and 3,4-dimethoxybenzaldehyde were not active against M. incognita in in vitro experiments led us to hypothesize a different mechanism of action rather than an effect on the external cuticle modification of nematodes. When the toxicity of the V-ATPase inhibitor pyocyanin (10) was tested against M. incognita J2 nematodes, an EC(50) at 24 h of 72 ± 25 mg/L was found. The redox-active compounds such as phthalaldehyde (1) and salicylaldehyde (2) may share a common mode of action inhibiting nematode V-ATPase enzyme. The results of this investigation reveal that aromatic redox-active aldehydes can be considered as potent nematicides, and further investigation is needed to completely clarify their mode of action. PMID:23379671

Caboni, Pierluigi; Aissani, Nadhem; Cabras, Tiziana; Falqui, Andrea; Marotta, Roberto; Liori, Barbara; Ntalli, Nikoletta; Sarais, Giorgia; Sasanelli, Nicola; Tocco, Graziella

2013-02-15

148

Effects of insect cadavers infected by Heterorhabditis bacteriophora and Steinernema diaprepesi on Meloidogyne incognita parasitism in pepper and summer squash plants/ Efecto de insectos cadáveres infectados por Heterorhabditis bacteriophora y Steinernema diaprepesi sobre el parasitismo de Meloidogyne incognita en plantas de pimiento y zapallito redondo de tronco  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish E.E. Del Valle, P. Lax, J. Rondán Dueñas y M.E. Doucet. 2013. Efecto de insectos cadáveres infectados por Heterorhabditis bacteriophora y Steinernema diaprepesi sobre el parasitismo de Meloidogyne incognita en plantas de pimiento y zapallito redondo de tronco. Cien. Inv. Agr. 40(1):109-118. El efecto de cadáveres de insectos infectados con tres aislados de Heterorhabditis bacteriophora y un aislado de Steinernema diaprepesi sobre una población de Meloidogyne incognit (more) a en plantas de pimiento (Capsicum annuum) y zapallito redondo de tronco (Cucurbita maxima) fue evaluado en experiencias de invernadero conducidas en Santa Fe (Argentina). Los cadáveres de insectos necesarios para la experiencia se obtuvieron infectando larvas de último estadio de Galleria mellonella y Tenebrio monitor con nematodos entomopatógenos. Dos cadáveres de seis días de infección se colocaron debajo de la superficie del suelo de macetas que fueron inoculadas con 100 juveniles de segundo estadio de M. incognita. A los sesenta días se registraron los siguientes parámetros en cada planta: número de hojas, peso seco de la parte aérea, número de agallas, masas de huevos y huevos, y número de agallas, masas de huevos y huevos g-1 de materia fresca radical. En pimiento, la única variable afectada por los cadáveres en relación al testigo fue el número de huevos de M. incognita en el tratamiento de cadáveres de T. molitor infectados con H. bacteriophora aislado Rama Caída. En zapallito redondo de tronco, varios tratamientos provocaron una disminución en el número de agallas y masas de huevos. Sólo la aplicación de cadáveres de G. mellonella infectados con H. bacteriophora aislado Rama Caída demostró ser eficiente en reducir el número de huevos de M. incognita. Nuestros resultados indicaron que la aplicación de cadáveres de insectos infectados con los nematodos entomopatógenos estudiados podría reducir los daños causados por M. incognita en plantas de pimiento y zapallito redondo de tronco. Abstract in english E. E. Del Valle, P. Lax, J. Rondán Dueñas, and M. E. Doucet. 2013. Effects of insect cadavers infected by Heterorhabditis bacteriophora and Steinernema diaprepesi on Meloidogyne incognita parasitism in pepper and summer squash plants. Cien. Inv. Agr. 40(1):109-118. The effects of insect cadavers infected with three isolates of Heterorhabditis bacteriophora and one isolate of Steinernema diaprepesi on a population of Meloidogyne incognita in pepper (Capsicum annuum) and (more) summer squash (Cucurbita maxima) were evaluated in greenhouse experiments carried out in Santa Fe (Argentina). Insect cadavers were obtained for the experiments from last instar larvae of Galleria mellonella and Tenebrio molitor that had been infected with entomopathogenic nematodes. Two six-day-old insect cadavers per pot were placed below the soil surface, and the soil was inoculated with 100 second-stage juveniles ofM incognita. Sixty days after inoculation, the following parameters were recorded for each plant: number of leaves; dry weight of aerial parts; numbers of galls, egg masses and eggs; and numbers of galls, egg masses and eggs g-1 of root fresh matter. In pepper, the only variable affected by the infected cadavers with respect to control was the number of eggs in the treatment involving T. molitor cadavers infected with the H. bacteriophora isolate Rama Caída. In summer squash, several treatments using infected cadavers resulted in a decrease in the numbers of galls and egg masses. Only the treatment involving G. mellonella cadavers infected with the H. bacteriophora isolate Rama Caída proved to be efficient in reducing the number of M. incognita eggs. Our results indicated that the application of insect cadavers infected with the entomopathogenic nematodes studied might reduce M. incognita damage in pepper and summer squash plants.

Del Valle, Eleodoro E; Lax, Paola; Rondán Dueñas, Juan; Doucet, Marcelo E

2013-04-01

149

Progênies de Coffea arabica cv. IPR 100 com resistência ao nematóide Meloidogyne incognita raça 1/ Progenies of Coffea arabica cv. IPR 100 with resistance to nematode Meloidogyne incognita race 1  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Objetivou-se, neste trabalho, identificar progênies de Coffea arabica cv. IPR 100 com resistência ao nematóide Meloidogyne incognita raça 1. O experimento foi conduzido em casa de vegetação (Londrina, PR, Brasil) no delineamento em blocos ao acaso com 3 repetições e parcelas com 15 plantas. Foram avaliadas seis progênies da cultivar IPR 100 e a cultivar Mundo Novo IAC 376-4 foi utilizada como padrão suscetível. Foram inoculados 500 ovos por planta, totalizando (more) 7500 ovos por parcela de 150 cm². Foi avaliado o número de galhas e massas de ovos presentes nas raízes. As seis progênies da cultivar IPR 100 foram mais resistentes ao M.incognita raça 1 do que o padrão suscetível. Abstract in english The objective of this study was to identify progenies of Coffea arabica cv. IPR 100 with resistance to nematode Meloidogyne incognita race 1. The experiment was performed in greenhouse (Londrina, PR, Brazil) with an experimental design of randomized blocks with 3 replications and 15 plants per plot. Six progenies of cultivar IPR 100 were evaluated, and Mundo Novo IAC 376-4 cultivar was used as susceptible control. Five hundred eggs per plant were inoculated, totalizing 75 (more) 00 eggs per plot of 150 cm². The number of galls and egg masses in the roots were evaluated. All progenies of cultivar IPR 100 presented more resistance to M.incognita race 1 than the susceptible control.

Kanayama, Fabio Seidi; Sera, Gustavo Hiroshi; Sera, Tumoru; Mata, João Siqueira da; Ruas, Paulo Maurício; Ito, Dhalton Shiguer

2009-10-01

150

Estreptomicetos no controle da meloidoginose em mudas de tomateiro Streptomycetes in the control of Meloidogyne incognita in tomato plants  

Directory of Open Access Journals (Sweden)

Full Text Available Este trabalho teve como objetivo avaliar o efeito de seis isolados de estreptomicetos na mortalidade e eclosão de juvenis de segundo estádio (J2) de Meloidogyne incognita e no controle da meloidoginose em mudas de tomateiro. Foi montado um bioensaio em placas tipo Elisa, sendo adicionados em cada célula, 200 µL de metabólitos dos isolados, com 20 µL de uma suspensão com 25 juvenis de segundo estádio (J2) de M. incognita. Os metabólitos produzidos por Streptomyces griseus subsp. griseus causaram 98,2% de mortalidade dos J2 de M. incognita. Em outro bioensaio, foram adicionados 3 mL dos metabólitos em frascos de vidro, com 100 µL da suspensão contendo 25 ovos de M.incognita. O isolado N0035 de Streptomyces proporcionou 98,8% de inibição na eclosão de J2 de M. incognita. Num terceiro bioensaio, o substrato de produção de mudas foi infestado com suspensão de estreptomicetos e incubado por 30 dias. Quinze dias depois da germinação das sementes do tomateiro, foi realizada a inoculação com 2.000 J2 por planta. Verificou-se a redução de 68% no número de galhas por grama de raiz e de 76,8% na massa de ovos por grama de raiz, nas mudas produzidas no substrato infestado e incubado com Streptomyces griseus subsp. griseus, quando comparado com a testemunha.This work aimed to evaluate the effect of six streptomycete isolates on mortality, hatching, and control of Meloidogyne incognita on tomato seedlings. An assay was conducted in Elisa plates, with the addition of 200 µL of the streptomycete metabolites, along with 20 µL of suspension containing 25 second stage juveniles (J2) of M. incognita. The metabolites produced by Streptomyces griseus subsp. griseus caused mortality of 98.2% on M. incognita. A second assay was conducted with 3 mL of streptomycete metabolites and 25 eggs of M. incognita. The isolate N0035 of Streptomyces caused inhibition of 98.8% on hatching. In a third assay, potting mix was infested with suspension of the streptomycetes isolates and incubated for 30 days. Fifteen days after germination, tomato seedlings were inoculated with a suspension containing 2,000 J2 of M. incognita. Reductions of 68% in the number of galls per gram of roots and of 76.8% in the egg mass per gram of roots were observed on tomato seedlings grown in the potting mix inoculated with Streptomyces griseus subsp. griseus, compared to the control.

Carla da Silva Sousa; Ana Cristina Fermino Soares; Marlon da Silva Garrido; Gabriela Maria Carneiro de Oliveira Almeida

2006-01-01

151

Bacterial mixture from greenhouse soil as a biocontrol agent against root-knot nematode, Meloidogyne incognita, on oriental melon.  

UK PubMed Central (United Kingdom)

The biological control efficacy of a greenhouse soil bacterial mixture of Lactobacillus farraginis, Bacillus cereus, and Bacillus thuringiensis strains with antinematode activity was evaluated against the root-knot nematode Meloidogyne incognita. Two control groups planted in soil drenched with sterile distilled water or treated with the broadspectrum carbamate pesticide carbofuran were used for comparison. The results suggest that the bacterial mixture is effective as a biocontrol agent against the root-knot nematode.

Seo BJ; Kumar VJ; Ahmad RI; Kim BC; Park W; Park SD; Kim SE; Kim SD; Lim J; Park YH

2012-01-01

152

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 endoparasitic root knot nematode, Meloidogyne incognita. Transgenic plants showed enhanced resistance against the root-knot nematode infection. Prominent differences in the shoot and root weights of wild type and transgenic plants were observed post-inoculation with M. incognita. This was associated with a decrease in the number of root galls and egg masses in transgenic plants compared to WT. The transgenic plants also showed constitutive and induced expression of some PR protein genes, when challenged with M. incognita.

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

2011-01-01

153

INFLUENCIA DE LA PLANTA HOSPEDANTE Y SU INTERACCIÓN CON Meloidogyne incognita SOBRE LA EFECTIVIDAD DE Pochonia chlamydosporia var. catenulata/ INFLUENCE OF THE HOST PLANT AND ITS INTERACTION WITH Meloidogyne incognita ON THE EFFECTIVENESS OF Pochonia chlamydosporia var. catenulata  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El efecto de las plantas hospedantes y su interacción con Meloidogyne incognita (Kofoid y White) Chitwood sobre la efectividad de Pochonia chlamydosporia var. catenulata (Kamyscho ex Barron y Onions) Zare y Gams como agente de control biológico de nematodos formadores de agallas se estudió en condiciones de aisladores biológicos. Para el desarrollo de la experiencia se utilizaron diferentes especies de plantas que se cultivan en los sistemas intensivos de producción (more) de hortalizas en Cuba y se evaluó la colonización de la rizosfera, a partir del conteo de UFC del hongo, en plantas sanas e infestadas por M. incognita. Los resultados demostraron que el crecimiento del hongo en la rizosfera varió en dependencia de la especie de planta. Entre los mejores hospedantes de P. chlamydosporia var. catenulata estuvieron la col, coliflor y acelga china, cultivos resistentes a M. incognita. Las plantas infestadas por M. incognita mostraron mayores niveles de colonización del hongo que las plantas sanas y el cultivo de la habichuela resultó ser un buen hospedante, en presencia del nematodo. Se recomienda la utilización de estos cultivos dentro de esquemas de rotación que incluyan la aplicación de P. chlamydosporia var. catenulata como agente de control biológico para el manejo de M. incognita en sistemas intensivos de producción de hortalizas. Abstract in english The effect of the host plants and their interaction with Meloidogyne incognita (Kofoid and White) Chitwood on the effectiveness of Pochonia chlamydosporia var. catenulata (Kamyscho ex Barron and Onions) Zare and Gams as a biological control agent of root-knot nematodes was studied in glasshouse conditions. Different plant species from the Cuban Intensive Vegetable Production Systems were used to perform the experience. The growth of the fungus in the rhizosphere differed (more) with the host plant. Among the best host plants of P. chlamydosporia var. catenulata were cabbage, salt-wort and cauliflower, resistant crops to M. incognita. The plants infested by M. incognita showed higher levels of fungus colonization than those healthy, and the kidney bean crop was a good host in the presence of the nematode. The use of these crops into rotation systems, with the application of Pochonia chlamydosporia var. catenulata as biological control agent for the management of M. incognita on Intensive Vegetable Production Systems, was recommended.

Puertas, Ana; Hidalgo-Díaz, L

2007-08-01

154

Comparative study of Fusarium oxysporum f sp. lycopersici and Meloidogyne incognita race-2 on plant growth parameters of tomato  

Directory of Open Access Journals (Sweden)

Full Text Available Many species of soil-inhabiting fungus Fusarium, cause severe yield loss in many crops. Experiments were conducted in net house condition with complete randomized block design to determine the individual effect of different in-oculum levels of root-knot nematode, Meloidogyne incognita, Race-2 and Fusarium oxysporum f sp. lycopersici on plant growth parameters viz., Plant length, fresh and dry weight and number of fruits of tomato var. P21. The experimental results showed that both the pathogens cause significant reduction in plant growth parameters. However, the fungus was not much effective on plant growth parameters in comparison to root-knot nematode. Greatest reduction in plant growth parameters was recorded in plants inoculated with 8000 J2/Kg soil of Meloidogyne in-cognita race 2. The threshold level of root-knot nematode was 1000 J2/kg soil while threshold level of Fusarium was @ 1 g/Kg soil. Inoculum level of Fusarium oxysporum f sp. lycopersici and Meloidogyne in-cognita race-2 was pathogenic and caused significant reduction at and above 1 g/kg soil and 1000 J2/Kg soil respectively.

Safiuddin   Sheila Shahab; Mohd. Mazid; Dania Ahmed

2012-01-01

155

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

Directory of Open Access Journals (Sweden)

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.

MARLUCI MUNDIN ABRÃO; PAULO MAZZAFERA

2001-01-01

156

Biological control potential of the obligate parasite Pasteuria penetransagainst the root-knot nematode, Meloidogyne incognita infestation in Brinjal.  

Science.gov (United States)

The efficacy of the obligate bacterial parasite, Pasteuria penetrans against the rootknot nematode, Meloidogyne incognita infestation was assessed in brinjal. The seedling pans with sterilized soil were inoculated with nematodes and root powder of P. penetrans were applied at different dosages viz., 0 x 10(6), 0.5 x 10(6) spores and 1 x 10(6) spores/pan. Seeds of brinjal cv Co2 were sown in the pans and seedlings were allowed to grow. The seedlings were transplanted to microplots containing sterilized soil. Observations on nematode infestation and plant growth were recorded at seedling, flowering, and fruiting stages. Nematode infestation was significantly reduced by P. penetrans treatment. There was 22, 75 and 86% reduction in nematode population of soil over control at seedling, flowering and fruiting stages, respectively, at higher spore density (1 x 10(6)). Egg mass production was decreased by 63, 78 and 89% over control at 35 (seedling), 100 (flowering) and 160 (fruiting) days after sowing respectively, at 1 x 10(6) spores treated soil. The parasitizing ability of P. penetrans increased with the age of the crop. At higher spore density the percentage of parasitization was increased from 52.0 (35 days after sowing) to 90.0 (160 days after sowing) %. At these stages of the crop, the spore load per juvenile also increased at the higher dose. The P. penetrans application enhanced the plant growth. The weight of the shoot was increased by 17.6% whereas root weight by 41.0% over the control at fruiting stage. The experimental results revealed the potential use of P. penetrans as biological control agent of M. incognita. Application of P. penetrans spores in the nursery is a good strategy since the mass multiplication is quite difficult. PMID:16628937

Kumari, N Swarna; Sivakumar, C V

2005-01-01

157

Biological control potential of the obligate parasite Pasteuria penetransagainst the root-knot nematode, Meloidogyne incognita infestation in Brinjal.  

UK PubMed Central (United Kingdom)

The efficacy of the obligate bacterial parasite, Pasteuria penetrans against the rootknot nematode, Meloidogyne incognita infestation was assessed in brinjal. The seedling pans with sterilized soil were inoculated with nematodes and root powder of P. penetrans were applied at different dosages viz., 0 x 10(6), 0.5 x 10(6) spores and 1 x 10(6) spores/pan. Seeds of brinjal cv Co2 were sown in the pans and seedlings were allowed to grow. The seedlings were transplanted to microplots containing sterilized soil. Observations on nematode infestation and plant growth were recorded at seedling, flowering, and fruiting stages. Nematode infestation was significantly reduced by P. penetrans treatment. There was 22, 75 and 86% reduction in nematode population of soil over control at seedling, flowering and fruiting stages, respectively, at higher spore density (1 x 10(6)). Egg mass production was decreased by 63, 78 and 89% over control at 35 (seedling), 100 (flowering) and 160 (fruiting) days after sowing respectively, at 1 x 10(6) spores treated soil. The parasitizing ability of P. penetrans increased with the age of the crop. At higher spore density the percentage of parasitization was increased from 52.0 (35 days after sowing) to 90.0 (160 days after sowing) %. At these stages of the crop, the spore load per juvenile also increased at the higher dose. The P. penetrans application enhanced the plant growth. The weight of the shoot was increased by 17.6% whereas root weight by 41.0% over the control at fruiting stage. The experimental results revealed the potential use of P. penetrans as biological control agent of M. incognita. Application of P. penetrans spores in the nursery is a good strategy since the mass multiplication is quite difficult.

Kumari NS; Sivakumar CV

2005-01-01

158

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

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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 s

Isabel Cristina Madeira Ferreira; Gilson Soares da Silva; Fagner Sousa Nascimento

2013-01-01

159

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 uti (more) lizados 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. Abstract in english 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 experime (more) nts. 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 differ

Ferreira, Isabel Cristina Madeira; Silva, Gilson Soares da; Nascimento, Fagner Sousa

2013-03-01

160

Resistance in Lycopersicon peruvianum to Isolates of Mi Gene-Compatible Meloidogyne Populations.  

Science.gov (United States)

Root-knot nematode resistance of F progeny of an intraspecific hybrid (Lycopersicon peruvianum var. glandulosum Acc. No. 126443 x L. peruvianum Acc. No. 270435), L. esculentum cv. Piersol (possessing resistance gene Mi), and L. esculentum cv. St. Pierre (susceptible) was compared. Resistance to 1) isolates of two Meloidogyne incognita populations artificially selected for parasitism on tomato plants possessing the Mi gene, 2) the wild type parent populations, 3) four naturally occurring resistance (Mi gene)-breaking populations of M. incognita, M. arenaria, and two undesignated Meloidogyne spp., and 4) a population of M. hapla was indexed by numbers of egg masses produced on root systems in a greenhouse experiment. Artificially selected M. incognita isolates reproduced abundantly on Piersol, but not (P = 0.01) on resistant F hybrids. Thus, the gene(s) for resistance in the F hybrid differs from the Mi gene in Piersol. Four naturally occurring resistance-breaking populations reproduced extensively on Piersol and on the F hybrid, demonstrating ability to circumvent both types of resistance. Meloidogyne hapla reproduced on F hybrid plants, but at significantly (P = 0.01) lower levels than on Piersol. PMID:19287762

Roberts, P A; Dalmasso, A; Cap, G B; Castagnone-Sereno, P

1990-10-01

 
 
 
 
161

Registro da ocorrência de Meloidogyne incognita no porta-enxerto 'IAC 766-Campinas' no estado de Pernambuco e reação de porta-enxertos e de cultivares copa de videira a Meloidogyne spp./ Meloidogyne incognita report on 'IAC 766-Campinas' rootstock in the state of Pernambuco and reaction of grape rootstocks and cultivars to Meloidogyne spp.  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Relata-se a ocorrência 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 raízes com numerosas galhas em meio ao cultivo de feijão-de-porco (Canavalia ensiformis), também atacado pelo nematoide. Com o objetivo de avaliar a resistência de quatro (more) porta-enxertos tropicais, oito de clima temperado, e as cultivares Niágara Rosada e Chardonnay quanto à reação a M. incognita e M. arenaria, em casa de vegetação, 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 inoculação, cada planta foi avaliada quanto ao número de galhas e número de ovos por planta, determinando-se, a seguir, o fator de reprodução de cada espécie do nematoide (FR=população inicial/população 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 (FR Abstract in english The occurrence of root-knot nematode Meloidogyne incognita (Est. I2) is reported in grapevine in Petrolina municipality, State of Pernambuco. Grape plants of Festival cultivar grafted on the 'IAC 766 - Campinas' rootstock attacked by M. incognita exhibited symptoms of less vigorous growth, yellowing and sparse leaves and multiple galls in the root system in an area cultivated with jack-bean (Canavalia ensiformis) also infected by the same nematode. In order to evaluate re (more) sistance of four tropical rootstocks, eight temperate and two cultivars Chardonnay and Niagara Rosada in reaction to M. incognita and M. arenaria, this study was carried out. Seedlings of the investigated grapevine genotypes were maintained in pots with sterilized soil and subsequently inoculated with 10,000 eggs + J2 of M. incognita or M. arenaria per plant in a six replicate design. Eight months after nematode inoculation, each plant was evaluated by counting gall and eggs. The final number of eggs (FP) of each Meloidogyne specie was calculated and the reproductive factor (RF = FP/IP), determined. Among the tested rootstocks, 'Harmony', 'Salt Creek', '1103 Paulsen', 'IAC 572-Jales', 'IAC 313-Tropical', 'K5BB Kober', 'SO4' , were resistant (RF

Somavilla, Lúcia; Gomes, Cesar Bauer; Quecini, Vera Maria

2012-09-01

162

Activity of Hydroxamic Acids from Secale cereale Against the Plant-Parasitic Nematodes Meloidogyne incognita and Xiphinema americanum.  

UK PubMed Central (United Kingdom)

ABSTRACT Cyclic hydroxamic acids are secondary metabolites found in the family Poaceae and have been implicated in the allelopathy of rye (Secale cereale). The toxicity of these compounds against plant-parasitic nematodes is unknown. DIBOA (2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one), DIMBOA (2,4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one), and their degradation products BOA (benzoxazolin-2(3H)-one) and MBOA (6-methoxy-benzoxazolin-2(3H)-one) were screened in vitro against Meloidogyne incognita second-stage juveniles (J2) and eggs and mixed-stages of Xiphinema americanum. Xiphinema americanum was more sensitive to DIBOA and DIMBOA than M. incognita J2, with a maximum apparent mortality of 96 and 92% compared to 73 and 72% at 90 mug/ml. Eggs of M. incognita were less sensitive to the hydroxamic acids than J2; only DIBOA resulted in a 50% reduction in egg hatch, with a lethal concentration (LC(50)) of 74 mug/ml compared to 21 mug/ml for J2. When M. incognita J2 were exposed to DIBOA for 48 h and the compound was removed and replaced with water, the LC(50) value increased from 21.0 to 40.7 mug/ml. MBOA was not toxic to X. americanum or M. incognita eggs, but was toxic to M. incognita J2, with LC(50) values of 44 and 20 mug/ml before and after the compound was removed and replaced with water. BOA was the least toxic hydroxamic acid tested; it did not reduce M. incognita egg hatch after 1 week of exposure or increase X. americanum mortality after 24 h of exposure. While in vitro studies provide a valuable starting point in determining the toxicity of the chemical component of rye, the relevance of the data to soil remains to be determined.

Zasada IA; Meyer SL; Halbrendt JM; Rice C

2005-10-01

163

Effects of benzyl isothiocyanate on the reproduction of Meloidogyne incognita on Glycine max and Capsicum annuum  

UK PubMed Central (United Kingdom)

Reproduction of Meloidogyne incognita on either Capsicum annuum or Glycine max was suppressed when infective second-stage juveniles (J2) were exposed to 0.03 mM benzyl isothiocyanate (BITC) for 2 h prior to inoculation of the host. Infectivity as rated by a gall index was significantly reduced on both G. max and C. annuum. In C. annuum, nematode egg masses were recovered from 48% of the plants inoculated with BITC-treated J2 compared with 98% for the controls, and egg mass scores were reduced. Egg mass production was reduced in C. annuum by 69% and mean total eggs/plant was reduced by 97% in G. max. When plants were inoculated with treated J2, two measures of plant health, root weight and shoot weight, were reduced in C. annuum but not in G. max. However, root and shoot weights were not correlated with egg production for either host plant, irrespective of treatment. There were strong interactions between egg production, as measured by mean total eggs/plant (G. max) or mean total eggs/egg mass (C. annuum), and hatching of J2 from eggs obtained from all combinations of plant host and J2 treatment. Hatch of J2 from eggs obtained from G. max was significantly lower when plants had been inoculated with BITC-treated J2 than when plants had been inoculated with control J2. Such effects were not observed with C. annuum. BITC may have important residual consequences on the progeny of M. incognita not directly exposed to the chemical.

Masler EdwardP; Zasada IngaA; Sardanelli Sandra; Rogers StephenT; Halbrendt JohnM

2010-01-01

164

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  

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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.

Jeane E de Medeiros; Rosa de LR Mariano; Elvira MR Pedrosa; Elineide B da Silveira

2009-01-01

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COMPORTAMIENTO DE MATERIALES DE LOS GÉNEROS Carica Y Vasconcellea FRENTE A Erwinia papayae, Meloidogyne incognita Y Rotylenchulus reniformis/ REACTION OF THE GENERA Carica AND Vasconcellea MATERIALS TO Erwinia papayae, Meloidogyne incognita AND Rotylenchulus reniformis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish La bacteriosis del cancro y el ataque de los nematodos constituyen graves obstáculos en la extensión del cultivo de la papaya (Carica papaya L.). El objetivo principal de este trabajo fue la selección de genotipos tanto comerciales como silvestres resistentes a los patógenos mencionados. Para la evaluación del comportamiento ante la bacteria del cancro causada por Erwinia papayae, se seleccionaron once accesiones de C. papaya, Vasconcellea goudotiana y V. cauliflora (more) y se inocularon 10 plantas de cada genotipo con una suspensión bacteriana de concentración de 10(8) UFC.mL-1. La inoculación se realizó produciendo heridas en los tallos de las plantas sanas. Los testigos se trataron de igual forma con agua destilada estéril. Para la evaluación de la resistencia a nematodos se realizaron dos experimentos; en el primero se utilizaron materiales de C. papaya y V. goudotiana, los cuales se inocularon con una población mixta de Meloidogyne incognita raza 1 y Rotylenchulus reniformis con 2000 huevos+juveniles.1000 cm-3 en suelo-arena estéril. Para el segundo experimento se usaron, además de los materiales mencionados, V. cauliflora, V. cundinamarcensis, V. microcarpa var. microcarpa, V. microcarpa var. pilifera, inoculados sólo con M. incognita raza 1 con 2500 huevos+juveniles.1000 cm-3. A las 12 semanas se calculó la población final y se midieron las siguientes variables: peso aéreo y radical fresco y seco. Los resultados del comportamiento de los genotipos frente a la bacteria determinó que V. goudotiana y V. cauliflora no se enfermaron, no así el género Carica, donde todas las plantas resultaron susceptibles, coincidiendo con la evaluación de nematodos, donde todas las accesiones de C. papaya y V. goudotiana fueron susceptibles y no tolerante al ataque de la población mixta de M. incognita raza 1 y R. reniformis, por afectarse las variables agronómicas evaluadas; mientras que la mayoría de los materiales de V. cundinamarcencis y V. microcarpa resultaron resistentes al ataque de M. incognita raza 1. Estos resultados permiten la obtención de genes de resistencias en los materiales silvestres, los cuales podrían ser incorporados a los genotipos mejorados o comerciales, y permitiría un mejor manejo de los patógenos mencionados, que resultan limitantes severos en el cultivo de papaya en Venezuela. Abstract in english The bacterial canker and the attack of nematodes are serious obstacles to the extension of Carica papaya L. crop. The main objective of this work was the selection of both commercial and wild genotypes resistant to the above mentioned pathogens. To assess the response to the bacterial canker caused by Erwinia papayae, eleven accesions of C. papaya, Vasconcellea goudotiana y V. cauliflora were selected and ten plants of each genotype were inoculated with a bacterial suspen (more) sion with a concentration of 10(8) CFU.mL-1 . The plants were inoculated by wounds on the stems of the healthy plants. The controls were similarly treated but with sterile distilled water. Two trials were carried out to evaluate the resistance to nematodes. In the first trial, materials of C. papaya and V. goudotiana were inoculated with a mixed population of Meloidogyne incognita race 1 and Rotylenchulus reniformis, with 2000 eggs+juveniles. 1000 cm-3 in sterile soil-sand. In the second trial, V. cauliflora, V. cundinamarcensis, V. microcarpa var. microcarpa and V. microcarpa var. pilifera, in addition to the genotypes previously used, were inoculated only with M. incognita race 1, with 2500 eggs+juvenils.1000 cm-3. After 12 weeks, the final population was calculated and the fresh and dried weights of the aerial parts and roots were determined. The results of the reaction of the genotypes towards the bacterium determined that V. goudotiana and V. cauliflora did not get the disease, what differed from the Carica genus, where all the plants resulted susceptible, a result that was similar to the evaluation to nematodes, where all the genotypes of C. papaya and V. goudotian

Maselli, Anna; Rosales, Ligia Carolina; Guevara, Yolanda; Suárez H, Zoraida

2010-12-01

166

Isolation of Nematicidal Triterpenoid Saponins from Pulsatilla koreana Root and Their Activities against Meloidogyne incognita  

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Full Text Available Pulsatilla koreana, a species endemic to Korea, is an important herb used in traditional medicine to treat amoebic dysentery and malaria. In the present study, 23 oleanane-type triterpenoid saponins 1–23 and eight lupane-type triterpenoid saponins 24–31 were isolated from the roots of P. koreana. Their structures were elucidated on the basis of spectroscopic data. The methanol extract and isolated compounds were next assessed for nematicidal activity against the root-knot nematode (Meloidogyne incognita). The methanol extract showed strong nematicidal activity after 48 h, with a LC50 value of 92.8 ?g/mL. Compounds 2, 5, 9, 20, and 21 showed significant effects, with LC50 values ranging from 70.1 to 94.7 ?g/mL after 48 h. These results suggest that triterpenoid saponins from P. koreana should be explored as potential natural nematicides for developing new agents to control root-knot nematode disease

Wei Li; Ya Nan Sun; Xi Tao Yan; Seo Young Yang; Suk Jun Lee; Hyo Jeung Byun; Chang Sup Moon; Byung Soo Han; Young Ho Kim

2013-01-01

167

Nematicidal Activity of Mint Aqueous Extracts against the Root-Knot Nematode Meloidogyne incognita.  

Science.gov (United States)

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

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

2013-10-03

168

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

UK PubMed Central (United Kingdom)

The nematicidal activity along with the chemical characterisation of aqueous extracts and essential oils of three mint species, namely Mentha x piperita, Mentha spicata and Mentha pulegium were investigated. The phytochemical analysis of the essential oils was performed by means of GC/MS, while the aqueous extracts were analysed by LC/MS. The most abundant terpenes were isomenthone, menthone, menthol, pulegone and carvone, while 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. x 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 the EC50/48h values of 127 and 730 mg/L respectively. On the other hand, salicylic acid, isolated in the aqueous extracts, exhibited values for EC50 at 24 and 48 hours of 298 ± 92 and 288 ± 79 mg/L respectively.

Caboni P; Saba M; Tocco G; Casu L; Murgia A; Maxia A; Menkissoglu-Spiroudi U; Ntalli N

2013-09-01

169

Nematicidal activity of allylisothiocyanate from horseradish (Armoracia rusticana) roots against Meloidogyne incognita.  

Science.gov (United States)

In recent years, there has been a great development in the search for new natural pesticides for crop protection aiming a partial or total replacement of currently used chemical nematicides. Glucosinolate breakdown products are volatile and are therefore good candidates for nematodes fumigants. In this article, the methanol-aqueous extract (1:1, w/v) of horseradish (Armoracia rusticana) fresh roots (MAH) was in vitro tested for nematicidal activity against second stage (J2) Meloidogyne incognita. The EC50 of MAH after 3 days of J2 immersion in test solutions was 251 ± 46 mg/L. The chemical composition analysis of the extract carried out by the GC-MS technique showed that allylisothicyanate was the most abundant compound. This pure compound induced J2 paralysis with an EC50 of 52.6 ± 45.6 and 6.6 ± 3.4 mg/L after 1 h and 3 days of incubation. The use of LC-MS/MS showed for the first time that horseradish root is rich in polyphenols. The study of isothiocyanate degradation in soil showed that allylisothiocyanate was the most quickly degradable compound (half-life <10 min), whereas no significant differences in half-life time were noted between degradation in regular and autoclaved soil. PMID:23627288

Aissani, Nadhem; Tedeschi, Paola; Maietti, Annalisa; Brandolini, Vincenzo; Garau, Vincenzo Luigi; Caboni, Pierluigi

2013-05-09

170

Nematicidal activity of allylisothiocyanate from horseradish (Armoracia rusticana) roots against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

In recent years, there has been a great development in the search for new natural pesticides for crop protection aiming a partial or total replacement of currently used chemical nematicides. Glucosinolate breakdown products are volatile and are therefore good candidates for nematodes fumigants. In this article, the methanol-aqueous extract (1:1, w/v) of horseradish (Armoracia rusticana) fresh roots (MAH) was in vitro tested for nematicidal activity against second stage (J2) Meloidogyne incognita. The EC50 of MAH after 3 days of J2 immersion in test solutions was 251 ± 46 mg/L. The chemical composition analysis of the extract carried out by the GC-MS technique showed that allylisothicyanate was the most abundant compound. This pure compound induced J2 paralysis with an EC50 of 52.6 ± 45.6 and 6.6 ± 3.4 mg/L after 1 h and 3 days of incubation. The use of LC-MS/MS showed for the first time that horseradish root is rich in polyphenols. The study of isothiocyanate degradation in soil showed that allylisothiocyanate was the most quickly degradable compound (half-life <10 min), whereas no significant differences in half-life time were noted between degradation in regular and autoclaved soil.

Aissani N; Tedeschi P; Maietti A; Brandolini V; Garau VL; Caboni P

2013-05-01

171

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

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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.

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

2011-01-01

172

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

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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 inoculum’s 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.

NEUCIMARA RODRIGUES RIBEIRO; JOÃO FLÁVIO VELOSO SILVA; WALTER FERNANDES MEIRELLES; ALINE GODOY CRAVEIRO; SIDNEY NETTO PARENTONI; FREDOLINO GIACOMINI DOS SANTOS

2002-01-01

173

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

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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, (AT)n, (AG)n and (CT)n 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 (AAT)n and (ATT)n 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.

Castagnone-Sereno Philippe; Danchin Etienne GJ; Deleury Emeline; Guillemaud Thomas; Malausa Thibaut; Abad Pierre

2010-01-01

174

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

UK PubMed Central (United Kingdom)

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, (AT)n, (AG)n and (CT)n 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 (AAT)n and (ATT)n 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.

Castagnone-Sereno P; Danchin EG; Deleury E; Guillemaud T; Malausa T; Abad P

2010-01-01

175

Reação de clones de batata-doce à Meloidogyne incognita raças 1 e 4 e estimativa de parâmetros genéticos/ Reaction of sweet potato clones to Meloidogyne incognita races 1 and 4, and estimation of genetic parameters  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo deste trabalho foi selecionar clones de batata-doce resistentes às raças 1 e 4 de Meloidogyne incognita, além de avaliar a eficiência do método de seleção empregado, pela estimativa de parâmetros genéticos. Foram avaliados 21 acessos do jardim clonal da Universidade de Brasília e três cultivares de batata-doce (Brazlândia Branca, Brazlândia Roxa e Amarela). O experimento foi conduzido em casa de vegetação, com delineamento de blocos casualizados (more) em arranjo simples, com 24 tratamentos, quatro repetições e três plantas por parcela. A inoculação do patógeno foi feita trinta dias após o plantio das ramas e, após noventa dias, foi feita a contagem do número médio de massas de ovos encontradas nas raízes das plantas inoculadas. Foram considerados resistentes os clones que apresentaram em média 0 a 1,9 massas de ovos por sistema radicular, moderadamente resistentes aqueles que apresentaram de 2,0 a 2,9 massas de ovos, moderadamente suscetíveis os que obtiveram número médio de massas de ovos variando entre 3,0 e 3,9, e suscetíveis aqueles com 4,0 a 5,0 massas de ovos por sistema radicular. Dos 24 materiais analisados, nove (37,5%) foram classificados como resistentes à raça 1 de M. incognita e 16 (66,67%) foram classificados como resistentes à M. incognita raça 4. Os clones 1200, 1210, 1199, 1229, 1230, 1202, 1231, 1216 e 1209 apresentaram resistência tanto à raça 1 quanto à raça 4 de M. incognita. A resistência das plantas a essas duas populações de nematoides testadas apresentou alta herdabilidade, e a relação entre os coeficientes de variação genético e ambiental do experimento para resistência à raça 4 de M. incognita apresentou-se mais baixa que aquela encontrada no outro experimento para resistência à raça 1. Abstract in english The objective of this work was to select sweet potato resistant clones to the races 1 and 4 of Meloidogyne incognita, and measure the efficiency of the selection method used, by means of the estimation of genetic and environmental coefficients of variation, and broad-sense heritabilities. We evaluated 21 accessions of the clonal garden of the Universidade de Brasilia, and three cultivars of sweet potato (Brazlândia Branca, Brazlândia Roxa and Amarela). The experiment wa (more) s carried out in a greenhouse with a randomized block design in simple arrangement, with 24 treatments, four replications and three plants per plot. The inoculation of the pathogen was made thirty days after planting the slips and, after ninety days, the counting of the average number of egg masses of the infected plants was completed. Clones were considered resistant when presented a number of egg masses per root system from 0 to 1.9, moderately resistant 2.0 to 2.9, moderately susceptible 3.0 to 3.9, and, susceptible 4.0 to 5.0. From 24 clones analyzed, nine (37.5%) were classified as resistant to the race 1 of M. incognita, and 16 (66.67%) were classified as resistant to the race 4 of M. incognita. The clones 1200, 1210, 1199, 1229, 1230, 1202, 1231, 1216 and 1209 were resistant to the two races tested of M. incognita. The resistance of the plants to these two races of root-knot nematodes presented high heritability, and the relationship between the coefficients of genetic and environmental variation of the experiment to resistance to race 4 of M. incognita was shorter than that one found in the another experiment, that aimed resistance to the race 1.

Kalkmann, Danielle C; Peixoto, José R; Nóbrega, Daiane da S

2013-06-01

176

Effects of vesicular-arbuscular mycorrhizal fungi on infection of tamarillo (Cyphomandra betacea) by Meloidogyne incognita in fumigated soil.  

UK PubMed Central (United Kingdom)

The effects of vesicular-arbuscular mycorrhizal (VAM) fungi on infection of tamarillo (Cyphomandra betacea) plants by root-knot nematodes (Meloidogyne incognita) were studied in fumigated soils with and without supplementary phosphate fertilizer. Nematodes severely reduced plant growth. In dually-inoculated plants, mycorrhizal infection improved plant growth and suppressed nematode reproduction and development in roots. Nematode infection and development were less in plants preinfected with mycorrhizal fungi than in plants inoculated simultaneously with both organisms. The benefit achieved by mycorrhizal inoculation could not be duplicated by adding phosphate fertilizer and was not therefore due merely to improved phosphorus nutrition of the host.

Cooper KM; Grandison GS

1987-12-01

177

Solanum torvum responses to the root-knot nematode Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

BACKGROUND: Solanum torvum Sw is worldwide employed as rootstock for eggplant cultivation because of its vigour and resistance/tolerance to the most serious soil-borne diseases as bacterial, fungal wilts and root-knot nematodes. The little information on Solanum torvum (hereafter Torvum) resistance mechanisms, is mostly attributable to the lack of genomic tools (e.g. dedicated microarray) as well as to the paucity of database information limiting high-throughput expression studies in Torvum. RESULTS: As a first step towards transcriptome profiling of Torvum inoculated with the nematode M. incognita, we built a Torvum 3' transcript catalogue. One-quarter of a 454 full run resulted in 205,591 quality-filtered reads. De novo assembly yielded 24,922 contigs and 11,875 singletons. Similarity searches of the S. torvum transcript tags catalogue produced 12,344 annotations. A 30,0000 features custom combimatrix chip was then designed and microarray hybridizations were conducted for both control and 14 dpi (day post inoculation) with Meloidogyne incognita-infected roots samples resulting in 390 differentially expressed genes (DEG). We also tested the chip with samples from the phylogenetically-related nematode-susceptible eggplant species Solanum melongena. An in-silico validation strategy was developed based on assessment of sequence similarity among Torvum probes and eggplant expressed sequences available in public repositories. GO term enrichment analyses with the 390 Torvum DEG revealed enhancement of several processes as chitin catabolism and sesquiterpenoids biosynthesis, while no GO term enrichment was found with eggplant DEG.The genes identified from S. torvum catalogue, bearing high similarity to known nematode resistance genes, were further investigated in view of their potential role in the nematode resistance mechanism. CONCLUSIONS: By combining 454 pyrosequencing and microarray technology we were able to conduct a cost-effective global transcriptome profiling in a non-model species. In addition, the development of an in silico validation strategy allowed to further extend the use of the custom chip to a related species and to assess by comparison the expression of selected genes without major concerns of artifacts. The expression profiling of S. torvum responses to nematode infection points to sesquiterpenoids and chitinases as major effectors of nematode resistance. The availability of the long sequence tags in S. torvum catalogue will allow precise identification of active nematocide/nematostatic compounds and associated enzymes posing the basis for exploitation of these resistance mechanisms in other species.

Bagnaresi P; Sala T; Irdani T; Scotto C; Lamontanara A; Beretta M; Rotino GL; Sestili S; Cattivelli L; Sabatini E

2013-01-01

178

Effects of ced-9 dsRNA on Caenorhabditis elegans and Meloidogyne incognita  

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Full Text Available Problem Statement: In metazoans Programmed Cell Death (PCD) is essential for proper development. Suppression of PCD is needed to guarantee cell survival and in the nematode Caenorhabditis elegans the regulation of PCD is accomplished by the function of the ced-9 gene. Approach: In this work the use of double stranded RNA (dsRNA) to knock-down ced-9 gene function was tested as means to induce PCD. Results: Our results indicate that dsRNA targeting the cell death protection gene ced-9 is effective at decreasing the fecundity of C. elegans by up to 21%. The decreased fecundity correlated with an increased presence of cell corpses in developing embryos. Endogenous ced-9 transcript levels were reduced in progeny of ced-3 mutant nematodes fed bacteria expressing ced-9 dsRNA. These data suggest that nematode fecundity can be reduced by ingestion and exposure to dsRNAs targeting regulation of the cell death pathway. In an attempt to determine if plant parasitic nematodes are susceptible to the targeting of the PCD regulatory pathway we exposed Meloidogyne incognita, a plant parasitic nematode, to ced-9 dsRNA; here we show that this exposure results in decreased gall formation in the tobacco plants. Conclusion/Recommendations: Our results provide the first steps toward using RNAi technologies to attempt nematode control by targeting cell death pathways. Ongoing research with transgenic plants designed to express dsRNA for ced-9-like sequences will further test the feasibility of generating plants with RNAi-based resistance to parasitic nematodes.

Robert T. Gaeta; Abdellatif Bahaji; Glenda W. Polack; Alejandro Calderon-Urrea

2011-01-01

179

Nematicidal activity of 3,4-dihydroxybenzoic acid purified from Terminalia nigrovenulosa bark against Meloidogyne incognita.  

Science.gov (United States)

In this study, the 3,4-dihydroxybenzoic acid (3,4-DHBA) from Terminalia nigrovenulosa bark (TNB) was purified and its in vitro nematicidal activity was investigated against Meloidogyne incognita. The purification of 3,4-DHBA used a silica gel column and Sephadex LH-20 chromatography combined with thin-layer chromatography and high performance liquid chromatography. Structural identification of the 3,4-DHBA was conducted using (1)H nuclear magnetic resonance (NMR), (13)C NMR, and liquid chromatography time-of-flight mass spectrometry. Nematicidal activity bioassays revealed that 3,4-DHBA treatment resulted in 33.3, 47.5, 72.5 and 94.2% J2 mortality at 0.125, 0.25, 0.5 and 1.0 mg/ml, respectively after 12 h incubation. J2 mortality was increased significantly (P < 0.0001) with increasing incubation time in the range of 54.2-94.2% from 3 to 9 h after incubation with 3,4-DHBA (1.0 mg/ml), but with no significant difference observed where the incubation time was increased from 9 to 12 h. The 3,4-DHBA treatment resulted in 33.3, 65.0, 76.7 and 85.0% hatch inhibition at 0.125, 0.25, 0.5 and 1.0 mg/ml, respectively, 3 days after incubation. Changes in the shape of the eggs were determined after incubation for 1 day with a 3,4-DHBA concentration of 1.0 mg/ml. PMID:23603737

Nguyen, Dang-Minh-Chanh; Seo, Dong-Jun; Kim, Kil-Yong; Park, Ro-Dong; Kim, Dong-Hyun; Han, Yeon-Soo; Kim, Tae-Hwan; Jung, Woo-Jin

2013-04-18

180

Nematicidal activity of 3,4-dihydroxybenzoic acid purified from Terminalia nigrovenulosa bark against Meloidogyne incognita.  

UK PubMed Central (United Kingdom)

In this study, the 3,4-dihydroxybenzoic acid (3,4-DHBA) from Terminalia nigrovenulosa bark (TNB) was purified and its in vitro nematicidal activity was investigated against Meloidogyne incognita. The purification of 3,4-DHBA used a silica gel column and Sephadex LH-20 chromatography combined with thin-layer chromatography and high performance liquid chromatography. Structural identification of the 3,4-DHBA was conducted using (1)H nuclear magnetic resonance (NMR), (13)C NMR, and liquid chromatography time-of-flight mass spectrometry. Nematicidal activity bioassays revealed that 3,4-DHBA treatment resulted in 33.3, 47.5, 72.5 and 94.2% J2 mortality at 0.125, 0.25, 0.5 and 1.0 mg/ml, respectively after 12 h incubation. J2 mortality was increased significantly (P < 0.0001) with increasing incubation time in the range of 54.2-94.2% from 3 to 9 h after incubation with 3,4-DHBA (1.0 mg/ml), but with no significant difference observed where the incubation time was increased from 9 to 12 h. The 3,4-DHBA treatment resulted in 33.3, 65.0, 76.7 and 85.0% hatch inhibition at 0.125, 0.25, 0.5 and 1.0 mg/ml, respectively, 3 days after incubation. Changes in the shape of the eggs were determined after incubation for 1 day with a 3,4-DHBA concentration of 1.0 mg/ml.

Nguyen DM; Seo DJ; Kim KY; Park RD; Kim DH; Han YS; Kim TH; Jung WJ

2013-06-01

 
 
 
 
181

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

Science.gov (United States)

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...

182

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

Scientific Electronic Library Online (English)

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

Anjos, Érika Cristina Teixeira dos; Cavalcante, Uided Maaze Tiburcio; Gonçalves, Danielle Maria Correia; Pedrosa, Elvira Maria Regis; Santos, Venézio Felipe dos; Maia, Leonor Costa

2010-08-01

183

Velvetbean (Mucuna pruriens) extracts: impact on Meloidogyne incognita survival and on Lycopersicon esculentum and Lactuca sativa germination and growth.  

Science.gov (United States)

Velvetbean (Mucuna spp.) is a summer annual that has been used as a cover crop to reduce erosion, fix nitrogen and suppress weeds and plant-parasitic nematodes. Crude aqueous extracts (1:15 dry weight plant/volume water) were made from velvetbean plant parts, and various concentrations of the extracts were evaluated in vitro for toxicities to different stages of Meloidogyne incognita (Kofoid and White) Chitwood and for suppression of hypocotyl and root growth and inhibition of germination of tomato (Lycopersicon esculentum L.) and lettuce (Lactuca sativa L.). Germination was only affected by the full-strength extract from leaf blades. Lettuce root growth was the most sensitive indicator of allelopathic activity of the plant part extracts. Lettuce and tomato root growth was more sensitive to the extract from main roots than to extracts of other plant parts, with lethal concentration (LC50) values of 1.2 and 1.1% respectively. Meloidogyne incognita egg hatch was less sensitive to extracts from velvetbean than the juvenile (J2) stage. There was no difference among LC50 values of the extracts from different plant parts against the egg stage. Based on LC50 values, the extract from fine roots was the least toxic to J2 (LC50 39.9%), and the extract from vines the most toxic (LC50 7.8%). The effects of the extracts were nematicidal because LC50 values did not change when the extracts were removed and replaced with water. PMID:16953489

Zasada, Inga A; Klassen, Waldemar; Meyer, Susan L F; Codallo, Maharanie; Abdul-Baki, Aref A

2006-11-01

184

Activity of Hydroxamic Acids from Secale cereale Against the Plant-Parasitic Nematodes Meloidogyne incognita and Xiphinema americanum.  

Science.gov (United States)

ABSTRACT Cyclic hydroxamic acids are secondary metabolites found in the family Poaceae and have been implicated in the allelopathy of rye (Secale cereale). The toxicity of these compounds against plant-parasitic nematodes is unknown. DIBOA (2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one), DIMBOA (2,4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one), and their degradation products BOA (benzoxazolin-2(3H)-one) and MBOA (6-methoxy-benzoxazolin-2(3H)-one) were screened in vitro against Meloidogyne incognita second-stage juveniles (J2) and eggs and mixed-stages of Xiphinema americanum. Xiphinema americanum was more sensitive to DIBOA and DIMBOA than M. incognita J2, with a maximum apparent mortality of 96 and 92% compared to 73 and 72% at 90 mug/ml. Eggs of M. incognita were less sensitive to the hydroxamic acids than J2; only DIBOA resulted in a 50% reduction in egg hatch, with a lethal concentration (LC(50)) of 74 mug/ml compared to 21 mug/ml for J2. When M. incognita J2 were exposed to DIBOA for 48 h and the compound was removed and replaced with water, the LC(50) value increased from 21.0 to 40.7 mug/ml. MBOA was not toxic to X. americanum or M. incognita eggs, but was toxic to M. incognita J2, with LC(50) values of 44 and 20 mug/ml before and after the compound was removed and replaced with water. BOA was the least toxic hydroxamic acid tested; it did not reduce M. incognita egg hatch after 1 week of exposure or increase X. americanum mortality after 24 h of exposure. While in vitro studies provide a valuable starting point in determining the toxicity of the chemical component of rye, the relevance of the data to soil remains to be determined. PMID:18943462

Zasada, I A; Meyer, S L F; Halbrendt, J M; Rice, C

2005-10-01

185

Effect of a formulation of Bacillus firmus on root-knot nematode Meloidogyne incognita infestation and the growth of tomato plants in the greenhouse and nursery.  

Science.gov (United States)

Bacillus firmus, commercial WP formulation (BioNem) was evaluated against the root-knot nematode Meloidogyne incognita in a laboratory, greenhouse and under field conditions on tomato plants. In the laboratory tests, an aqueous suspension of BioNem at 0.5%, 1%, 1.5% and 2% concentration reduced egg hatching from 98% to 100%, 24-days after treatment. Treatment of second-stage juveniles with 2.5% and 3% concentration of BioNem, caused 100% inhibition of mobility, 24 h after treatment. In the green house trials, BioNem applied at 8 g/pot (1200 cc soil) planted with a tomato seedlings reduced gall formation by 91%, final nematode populations by 76% and the number of eggs by 45%. Consequently, plant height and biomass was increased by 71% and 50%, respectively, compared to the untreated control, 50-days after treatment application. Application of BioNem at 16 g/pot was phytotoxic to plants. In the field trails, BioNem applied at 200 and 400 kg ha(-1) was effective in reducing the number of galls (75-84%), and increased shoot height (29-31%) and weight (20-24%) over the untreated control, 45-days after treatment. Our results indicate that B. firmus is a promising microorganism for the biological control of M. incognita in tomato pots. PMID:19041655

Terefe, Metasebia; Tefera, Tadele; Sakhuja, P K

2008-11-14

186

EFECTO DEL MOMENTO DE APLICACIÓN DE Pochonia chlamydosporia var. CATENULATA SOBRE SU EFICACIA EN EL CONTROL DE MELOIDOGYNE INCOGNITA/ EFFECTS OF Pochonia chlamydosporia var. CATENULATE APPLICATION MOMENTS OVER ITS EFFICACY IN CONTROLLING MELOIDOGYNE INCOGNITA  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se estudió el efecto del momento de aplicación de la cepa IMI SD 187 de Pochonia chlamydosporia var. catenulata sobre su abundancia en el suelo y la rizosfera, así como su capacidad para colonizar las masas de huevos y el parasitismo de los huevos de Meloidogyne incognita en el cultivo del tomate (Solanum lycopersicum L.), con el objetivo de perfeccionar el uso práctico de este agente de control biológico. Los resultados demostraron que la colonización del sustrato (more) y raíces, así como la capacidad parasítica de P. chlamydosporia var. catenulata fueron superiores con la aplicación del hongo al sustrato en el transplante. No obstante, la aplicación al sustrato del cepellón permitió que los niveles de colonización alcanzados en las raíces del cultivo del tomate por P. chlamydosporia var. catenulata proporcionaran un 60% de parasitismo de huevos, aspecto a tener en cuenta cuando los niveles de infestación por M. incognita sean bajos o se deseen realizar aplicaciones preventivas. Abstract in english To improve the biological control agent practical use, the effect of the application moment of the strain IMI SD 187 of Pochonia chlamydosporia var. catenulata on its abundance in soil and rhizosphere, as well as its capability of egg mass colonization and egg parasitism of M. incognita on tomato (Solanum lycopersicum L.) crop was studied. The results provided that the substrate and root colonization and the parasitic capability of P. chlamydosporia var. catenulata were h (more) igher with the fungus application in the substrate at transplanting. Nevertheless, the application on the tray substrate at sowing allowed the levels of root colonization reached by P. chlamydosporia var. catenulata to provide a 60% of egg parasitism which is a percentage to be taken into account at low infestation levels by M. incognita or at preventive applications.

Puertas, Ana; Hidalgo-Díaz, L

2009-12-01

187

Efeito de manipueira sobre Meloidogyne incognita em ensaios in vitro e em tomateiros em casa de vegetação/ Effect of manipueira on Meloidogyne incognita through in vitro and in vivo essays on tomatoes in greenhouse  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Objetivou-se estudar o efeito nematicida de manipueira no controle de Meloidogyne incognita. Testes in vitro foram divididos em dois ensaios inteiramente casualizados: 1. manipueira a 100%, 75%, 50% e 25% em 12 repetições; 2. manipueira a 15%, 10%, 8%, 6%, 4% e 2% em 5 repetições. O ensaio em vasos seguiu o delineamento inteiramente casualisado com manipueira a 10%, 25% e 50% em 5 repetições. Para ambos os ensaios utilizou-se o tratamento somente água como testemun (more) ha positiva e Carbofuran (50 mg.L-1 de ingrediente ativo (i.a.) ou 2 g de produto comercial/vaso) como negativa. Para os ensaios in vitro foram avaliados nematóides vivos e mortos e número de galhas em plantas inoculadas. Para os ensaios em vaso foram avaliadas as variáveis altura de plantas, comprimento de raízes, número de galhas, número de ovos e fator de reprodução (FR). Os resultados in vitro demonstraram que os tratamentos com manipueira até 10% de diluição apresentaram 100% de controle. O ensaio com tomateiros previamente inoculados demonstrou que o tratamento manipueira 50% causou um melhor desenvolvimento da parte aérea das plantas de tomate. Os tratamentos manipueira a 10% e 25% foram mais efetivos no controle de M. incognita em vasos. Abstract in english The aim of this work was to study the nematicidal effect of manipueira on the control of Meloidogyne incognita. In vitro tests were split into two completely randomized assays: 1. manipueira 100%, 75%, 50% and 25% in 12 replications; 2. manipueira 15%, 10%, 8%, 6%, 4% and 2% in 5 replications. The pot assay followed a completely randomized design with the treatments manipueira 10%, 25% and 50% in 5 replications. For both assays the positive control was water and the negat (more) ive control was the nematicide Carbofuran (50 mg.L-1 of active ingredient (a.i.) or 2 g of commercial product/pot). For in vitro assays the variables assessed were live or dead nematodes and number of galls on inoculated plants. For the pot assay the variables evaluated were plant height, root length, number of galls, number of eggs and reproduction factor (RF). The in vitro results indicated that only the manipueira treatments from 100% to 10% dilution showed maximum control. The pot assay demonstrated that the treatment manipueira 50% caused better development of tomato shoots than the others. However, manipueira 10% and 25% were more effective against of M. incognita in pots.

Nasu, Érica G.C.; Pires, Ely; Formentini, Heloísa M.; Furlanetto, Cleber

2010-02-01

188

Efeito de manipueira sobre Meloidogyne incognita em ensaios in vitro e em tomateiros em casa de vegetação Effect of manipueira on Meloidogyne incognita through in vitro and in vivo essays on tomatoes in greenhouse  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivou-se estudar o efeito nematicida de manipueira no controle de Meloidogyne incognita. Testes in vitro foram divididos em dois ensaios inteiramente casualizados: 1. manipueira a 100%, 75%, 50% e 25% em 12 repetições; 2. manipueira a 15%, 10%, 8%, 6%, 4% e 2% em 5 repetições. O ensaio em vasos seguiu o delineamento inteiramente casualisado com manipueira a 10%, 25% e 50% em 5 repetições. Para ambos os ensaios utilizou-se o tratamento somente água como testemunha positiva e Carbofuran (50 mg.L-1 de ingrediente ativo (i.a.) ou 2 g de produto comercial/vaso) como negativa. Para os ensaios in vitro foram avaliados nematóides vivos e mortos e número de galhas em plantas inoculadas. Para os ensaios em vaso foram avaliadas as variáveis altura de plantas, comprimento de raízes, número de galhas, número de ovos e fator de reprodução (FR). Os resultados in vitro demonstraram que os tratamentos com manipueira até 10% de diluição apresentaram 100% de controle. O ensaio com tomateiros previamente inoculados demonstrou que o tratamento manipueira 50% causou um melhor desenvolvimento da parte aérea das plantas de tomate. Os tratamentos manipueira a 10% e 25% foram mais efetivos no controle de M. incognita em vasos.The aim of this work was to study the nematicidal effect of manipueira on the control of Meloidogyne incognita. In vitro tests were split into two completely randomized assays: 1. manipueira 100%, 75%, 50% and 25% in 12 replications; 2. manipueira 15%, 10%, 8%, 6%, 4% and 2% in 5 replications. The pot assay followed a completely randomized design with the treatments manipueira 10%, 25% and 50% in 5 replications. For both assays the positive control was water and the negative control was the nematicide Carbofuran (50 mg.L-1 of active ingredient (a.i.) or 2 g of commercial product/pot). For in vitro assays the variables assessed were live or dead nematodes and number of galls on inoculated plants. For the pot assay the variables evaluated were plant height, root length, number of galls, number of eggs and reproduction factor (RF). The in vitro results indicated that only the manipueira treatments from 100% to 10% dilution showed maximum control. The pot assay demonstrated that the treatment manipueira 50% caused better development of tomato shoots than the others. However, manipueira 10% and 25% were more effective against of M. incognita in pots.

Érica G.C. Nasu; Ely Pires; Heloísa M. Formentini; Cleber Furlanetto

2010-01-01

189

Short interfering RNA-mediated gene silencing in Globodera pallida and Meloidogyne incognita infective stage juveniles.  

Science.gov (United States)

The analysis of gene function through RNA interference (RNAi)-based reverse genetics in plant parasitic nematodes (PPNs) remains inexplicably reliant on the use of long double-stranded RNA (dsRNA) silencing triggers; a practice inherently disadvantageous due to the introduction of superfluous dsRNA sequence, increasing chances of aberrant or off-target gene silencing through interactions between nascent short interfering RNAs (siRNAs) and non-cognate mRNA targets. Recently, we have shown that non-nematode, long dsRNAs have a propensity to elicit profound impacts on the phenotype and migrational abilities of both root knot and cyst nematodes. This study presents, to our knowledge for the first time, gene-specific knockdown of FMRFamide-like peptide (flp) transcripts, using discrete 21bp siRNAs in potato cyst nematode Globodera pallida, and root knot nematode Meloidogyne incognita infective (J2) stage juveniles. Both knockdown at the transcript level through quantitative (q)PCR analysis and functional data derived from migration assay, indicate that siRNAs targeting certain areas of the FMRFamide-like peptide (FLP) transcripts are potent and specific in the silencing of gene function. In addition, we present a method of manipulating siRNA activity through the management of strand thermodynamics. Initial evaluation of strand thermodynamics as a determinant of RNA-Induced Silencing Complex (RISC) strand selection (inferred from knockdown efficacy) in the siRNAs presented here suggested that the purported influence of 5' stand stability on guide incorporation may be somewhat promiscuous. However, we have found that on strategically incorporating base mismatches in the sense strand of a G. pallida-specific siRNA, we could specifically increase or decrease the knockdown of its target (specific to the antisense strand), presumably through creating more favourable thermodynamic profiles for incorporation of either the sense (non-target-specific) or antisense (target-specific) strand into a cleavage-competent RISC. Whilst the efficacy of similar approaches to siRNA modification has been demonstrated in the context of Drosophila whole-cell lysate preparations and in mammalian cell cultures, it remained to be seen how these sense strand mismatches may impact on gene silencing in vivo, in relation to different targets and in different sequence contexts. This work presents the first application of such an approach in a whole organism; initial results show promise. PMID:19651131

Dalzell, Johnathan J; McMaster, Steven; Fleming, Colin C; Maule, Aaron G

2009-08-03

190

Short interfering RNA-mediated gene silencing in Globodera pallida and Meloidogyne incognita infective stage juveniles.  

UK PubMed Central (United Kingdom)

The analysis of gene function through RNA interference (RNAi)-based reverse genetics in plant parasitic nematodes (PPNs) remains inexplicably reliant on the use of long double-stranded RNA (dsRNA) silencing triggers; a practice inherently disadvantageous due to the introduction of superfluous dsRNA sequence, increasing chances of aberrant or off-target gene silencing through interactions between nascent short interfering RNAs (siRNAs) and non-cognate mRNA targets. Recently, we have shown that non-nematode, long dsRNAs have a propensity to elicit profound impacts on the phenotype and migrational abilities of both root knot and cyst nematodes. This study presents, to our knowledge for the first time, gene-specific knockdown of FMRFamide-like peptide (flp) transcripts, using discrete 21bp siRNAs in potato cyst nematode Globodera pallida, and root knot nematode Meloidogyne incognita infective (J2) stage juveniles. Both knockdown at the transcript level through quantitative (q)PCR analysis and functional data derived from migration assay, indicate that siRNAs targeting certain areas of the FMRFamide-like peptide (FLP) transcripts are potent and specific in the silencing of gene function. In addition, we present a method of manipulating siRNA activity through the management of strand thermodynamics. Initial evaluation of strand thermodynamics as a determinant of RNA-Induced Silencing Complex (RISC) strand selection (inferred from knockdown efficacy) in the siRNAs presented here suggested that the purported influence of 5' stand stability on guide incorporation may be somewhat promiscuous. However, we have found that on strategically incorporating base mismatches in the sense strand of a G. pallida-specific siRNA, we could specifically increase or decrease the knockdown of its target (specific to the antisense strand), presumably through creating more favourable thermodynamic profiles for incorporation of either the sense (non-target-specific) or antisense (target-specific) strand into a cleavage-competent RISC. Whilst the efficacy of similar approaches to siRNA modification has been demonstrated in the context of Drosophila whole-cell lysate preparations and in mammalian cell cultures, it remained to be seen how these sense strand mismatches may impact on gene silencing in vivo, in relation to different targets and in different sequence contexts. This work presents the first application of such an approach in a whole organism; initial results show promise.

Dalzell JJ; McMaster S; Fleming CC; Maule AG

2010-01-01

191

Efeito da incorporação de sementes trituradas defeijão de porco ao solo sobre o parasitismo de Meloidogyne incognita em tomateiro Effect of soil amendment with powdered seeds of pig bean on Meloidogyne incognita in tomato  

Directory of Open Access Journals (Sweden)

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.A greenhouse experiment was carried out to study the effect of powdered seeds of pig bean (Canavalia ensiformis) incorporated into the soil, for the control of Meloidogyne incognita race 1 in tomato (Lycopersicon esculentum) plants. Autoclaved soil was amended with 2.5, 5.0, 7.5 and 10.0 g of powdered seeds/kg of soil. Soil without amendment served as control. For comparison, the nematicide Carbofuran was included as an additional treatment. Nematode was controlled at rates above 5.0 g. Gall and egg mass indexes were reduced by 48% and 64%, respectively, with the application of 10 g of powdered seeds/kg of soil.

GILSON S. SILVA; ILKA M. R. SOUZA; FLÁVIA A. CUTRIM

2002-01-01

192

Reação de clones de bananeira(Musa spp.) ao nematóide Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949, Raça 2 Reaction of banana clones (Musa spp.) to nematode Meloidogyne incognita (kofoid & White, 1919) chitwood, 1949, race 2  

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Full Text Available O trabalho teve por objetivo estudar em condições de casa de vegetação a reação de clones de bananeira, em relação a Meloidogyne incognita raça 2. Mudas micropropagadas foram inoculadas, utilizando-se da suspensão de M. incognita, formada de ovos e de juvenis do segundo estádio, totalizando 20.000 / muda. A inoculação foi feita após cinco dias do transplante das mudas para sacos de plástico preto de cinco litros de capacidade, contendo solo, areia e esterco, na proporção 3:1:1, esterilizado em caldeira a 100ºC, por duas horas. O delineamento experimental foi o inteiramente casualizado, com quatro repetições. Após 120 dias, os clones foram avaliados. Determinou-se o número de ovos e juvenis contido no sistema radicular, sendo utilizado o clone CPA-34, a cultivar Grande Naine, como padrão de suscetibilidade. Amostras de 200 cm³ de solo foram coletadas para a determinação do número de nematóides no solo. De acordo com os fatores de reprodução (Pf/Pi), verificou-se que o clone CPA-34 apresentou-se suscetível ao nematóide, como era esperado, com o maior fator de reprodução, seguido do clone CPA-49, da cultivar Maçã, com índice superior a um. Os demais clones testados apresentaram fator de reprodução menor que um, indicando certa resistência ao nematóide M. incognita raça 2. Entretanto, nas análises estatísticas, foram verificadas diferenças significativas entre o clone-padrão CPA-34, quando comparado com os clones CPA-58 e CPA-54. Para os resultados de peso de raízes e peso da parte aérea, a diferença foi significativa (1%) para todos os clones testados, apresentando os maiores valores para os clones não inoculados.The aim of this work was to study banana clones reaction in relation to Meloidogyne incognita race 2, under greenhouse conditions. The plants were inoculated with a suspension of 20,000 M. incognita which includes the presence of eggs and second stage juveniles. The inoculation occurred five days after the seedlings were transplanted to a plastic bag (5L) which contains soil, sand and manure, with 3:1:1 rate, and this was sterilized at 100ºC during two hours. The experimental outline was at random with four replications. The clones were evaluated after 120 days inoculation. The number of eggs and juveniles in the root system were determined. The clone CPA-34 from Grande Naine variety was used as susceptibility standard. Soil samples of 200cm³ were collected to determine the number of nematodes present in the soil. According to reproduction factors (FP/IP), as it was expected, it was shown that the clone CPA-34 is susceptible to the nematode, with the highest reproduction rate followed by the clone CPA-49 from Maçã variety, with FP/IP above one. The other tested clones showed reproduction rate below one, which indicates a certain resistance to M. incognita race 2. However, statistical analysis demonstrate significant differences between the standard clone CPA-34 compared to clones CPA-58 and CPA-54. The results of root weight and aerial part weight, showed a significant difference (1%) for all tested clones, with higher rates for the non-inoculated clones.

Lenisa Cezar Vilas Boas; Renata Cesar Vilardi Tenente; Vilmar Gonzaga; Sebastião Pedro da Silva Neto; Herminio Souza Rocha

2002-01-01

193

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

Directory of Open Access Journals (Sweden)

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.

SILVA GILSON S.; SOUZA ILKA M. R.; CUTRIM FLÁVIA A.

2002-01-01

194

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

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Full Text Available Foram conduzidos dois experimentos, sob condições de estufa de produção, com o objetivo de avaliar a reação de oito genótipos de milho em relação aos nematóides formadores de galhas Meloidogyne javanica e M. incognita. Foram testados os híbridos DINA-657, DINA-766, DINA-170, HATÃ-1045, HATÃ-1001, FT-5140, CO-9560 E CO-32. Com relação a M. javanica, observou-se que as cultivares HATÃ-1001, HATÃ-1045, DINA-657 E FT-5140 apresentam os menores fatores de reprodução, destacando-se para uso em programas de rotação de culturas com a soja. Todas as cultivares testadas comportaram-se como boas multiplicadoras de M. incognita, apresentando fatores de reprodução superiores a 3,98. Estas cultivares não devem ser recomendadas para áreas infestadas por esta espécie de nematóide. PALAVRAS-CHAVE: Resistência; nematóides de galhas; milho. Two experiments were carried out under greenhouse conditions with the objective of evaluating the reaction of eight corn genotypes to the root-knot nematodes Meloidogyne javanica and M. incognita. Cultivars HATÃ-1001, HATÃ-1045, DINA-657 and FT-5140 presented smaller reproduction factors (RF) for M. javanica. Therefore, the use of these cultivars may be indicated in the crop rotation program with soybean. All cultivars were suitable hosts for M. incognita, presenting RF higher than 3.98. KEY-WORDS: Resistance; root-knot; nematodes; corn.

Hércules Diniz Campos; Mara Rúbia da Rocha

2007-01-01

195

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  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 inteirame (more) nte 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. Abstract in english 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- (more) 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.

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

2012-06-01

196

Volatile Substances Produced by Fusarium oxysporum from Coffee Rhizosphere and Other Microbes affect Meloidogyne incognita and Arthrobotrys conoides.  

UK PubMed Central (United Kingdom)

Microorganisms produce volatile organic compounds (VOCs) which mediate interactions with other organisms and may be the basis for the development of new methods to control plant-parasitic nematodes that damage coffee plants. In the present work, 35 fungal isolates were isolated from coffee plant rhizosphere, Meloidogyne exigua eggs and egg masses. Most of the fungal isolates belonged to the genus Fusarium and presented in vitro antagonism classified as mutual exclusion and parasitism against the nematode-predator fungus Arthrobotrys conoides (isolated from coffee roots). These results and the stronger activity of VOCs against this fungus by 12 endophytic bacteria may account for the failure of A. conoides to reduce plant-parasitic nematodes in coffee fields. VOCs from 13 fungal isolates caused more than 40% immobility to Meloidogyne incognita second stage juveniles (J2), and those of three isolates (two Fusarium oxysporum isolates and an F. solani isolate) also led to 88-96% J2 mortality. M. incognita J2 infectivity decreased as a function of increased exposure time to F. oxysporum isolate 21 VOCs. Gas chromatography-mass spectrometry (GC-MS) analysis lead to the detection of 38 VOCs produced by F. oxysporum is. 21 culture. Only five were present in amounts above 1% of the total: dioctyl disulfide (it may also be 2-propyldecan-1-ol or 1-(2-hydroxyethoxy) tridecane); caryophyllene; 4-methyl-2,6-di-tert-butylphenol; and acoradiene. One of them was not identified. Volatiles toxic to nematodes make a difference among interacting microorganisms in coffee rhizosphere defining an additional attribute of a biocontrol agent against plant-parasitic nematodes.

Freire ES; Campos VP; Pinho RS; Oliveira DF; Faria MR; Pohlit AM; Noberto NP; Rezende EL; Pfenning LH; Silva JR

2012-12-01

197

Volatile Substances Produced by Fusarium oxysporum from Coffee Rhizosphere and Other Microbes affect Meloidogyne incognita and Arthrobotrys conoides.  

Science.gov (United States)

Microorganisms produce volatile organic compounds (VOCs) which mediate interactions with other organisms and may be the basis for the development of new methods to control plant-parasitic nematodes that damage coffee plants. In the present work, 35 fungal isolates were isolated from coffee plant rhizosphere, Meloidogyne exigua eggs and egg masses. Most of the fungal isolates belonged to the genus Fusarium and presented in vitro antagonism classified as mutual exclusion and parasitism against the nematode-predator fungus Arthrobotrys conoides (isolated from coffee roots). These results and the stronger activity of VOCs against this fungus by 12 endophytic bacteria may account for the failure of A. conoides to reduce plant-parasitic nematodes in coffee fields. VOCs from 13 fungal isolates caused more than 40% immobility to Meloidogyne incognita second stage juveniles (J2), and those of three isolates (two Fusarium oxysporum isolates and an F. solani isolate) also led to 88-96% J2 mortality. M. incognita J2 infectivity decreased as a function of increased exposure time to F. oxysporum isolate 21 VOCs. Gas chromatography-mass spectrometry (GC-MS) analysis lead to the detection of 38 VOCs produced by F. oxysporum is. 21 culture. Only five were present in amounts above 1% of the total: dioctyl disulfide (it may also be 2-propyldecan-1-ol or 1-(2-hydroxyethoxy) tridecane); caryophyllene; 4-methyl-2,6-di-tert-butylphenol; and acoradiene. One of them was not identified. Volatiles toxic to nematodes make a difference among interacting microorganisms in coffee rhizosphere defining an additional attribute of a biocontrol agent against plant-parasitic nematodes. PMID:23482720

Freire, E S; Campos, V P; Pinho, R S C; Oliveira, D F; Faria, M R; Pohlit, A M; Noberto, N P; Rezende, E L; Pfenning, L H; Silva, J R C

2012-12-01

198

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  

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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.

Fernando S. Rocha; Vicente P. Campos

2004-01-01

199

Management of Meloidogyne incognita with tall fescue grass rotations prior to peach orchard establishment  

Science.gov (United States)

Root-knot nematodes (Meloidogyne spp.) are important pests of peach in the USA. Preplant fumigant nematicides have been used to control Meloidogyne spp. associated with Southeastern peach production. Unfortunately, growers have increasingly faced economic challenges, making it difficult for them t...

200

The 8D05 parasitism gene of Meloidogyne incognita is required for successful infection of host roots.  

UK PubMed Central (United Kingdom)

Parasitism genes encode effector proteins that are secreted through the stylet of root-knot nematodes to dramatically modify selected plant cells into giant-cells for feeding. The Mi8D05 parasitism gene previously identified was confirmed to encode a novel protein of 382 amino acids that had only one database homolog identified on contig 2374 within the Meloidogyne hapla genome. Mi8D05 expression peaked in M. incognita parasitic second-stage juveniles within host roots and its encoded protein was limited to the subventral esophageal gland cells that produce proteins secreted from the stylet. Constitutive expression of Mi8D05 in transformed Arabidopsis thaliana plants induced accelerated shoot growth and early flowering but had no visible effects on root growth. Independent lines of transgenic Arabidopsis that expressed a double-stranded RNA complementary to Mi8D05 in host-derived RNA interference (RNAi) tests had up to 90% reduction in infection by M. incognita compared with wild-type control plants, suggesting that Mi8D05 plays a critical role in parasitism by the root-knot nematode. Yeast two-hybrid experiments confirmed the specific interaction of the Mi8D05 protein with plant aquaporin tonoplast intrinsic protein 2 (TIP2) and provided evidence that the Mi8D05 effector may help regulate solute and water transport within giant-cells to promote the parasitic interaction.

Xue B; Hamamouch N; Li C; Huang G; Hussey RS; Baum TJ; Davis EL

2013-02-01

 
 
 
 
201

The 8D05 parasitism gene of Meloidogyne incognita is required for successful infection of host roots.  

Science.gov (United States)

Parasitism genes encode effector proteins that are secreted through the stylet of root-knot nematodes to dramatically modify selected plant cells into giant-cells for feeding. The Mi8D05 parasitism gene previously identified was confirmed to encode a novel protein of 382 amino acids that had only one database homolog identified on contig 2374 within the Meloidogyne hapla genome. Mi8D05 expression peaked in M. incognita parasitic second-stage juveniles within host roots and its encoded protein was limited to the subventral esophageal gland cells that produce proteins secreted from the stylet. Constitutive expression of Mi8D05 in transformed Arabidopsis thaliana plants induced accelerated shoot growth and early flowering but had no visible effects on root growth. Independent lines of transgenic Arabidopsis that expressed a double-stranded RNA complementary to Mi8D05 in host-derived RNA interference (RNAi) tests had up to 90% reduction in infection by M. incognita compared with wild-type control plants, suggesting that Mi8D05 plays a critical role in parasitism by the root-knot nematode. Yeast two-hybrid experiments confirmed the specific interaction of the Mi8D05 protein with plant aquaporin tonoplast intrinsic protein 2 (TIP2) and provided evidence that the Mi8D05 effector may help regulate solute and water transport within giant-cells to promote the parasitic interaction. PMID:23294405

Xue, Bingye; Hamamouch, Noureddine; Li, Chunying; Huang, Guozhong; Hussey, Richard S; Baum, Thomas J; Davis, Eric L

2013-02-01

202

RNAi of MiASB caused high mortality of Meloidogyne incognita juveniles and inhibited the nematode disease  

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Full Text Available The southern root-knot nematode, Meloidogyne incognita, is one of the most prevalent and damaging plant-parasitic nematodes in the world and causes serious damages to agricultural production. We cloned a mitochondrial ATP synthase b subunit gene fragment of M. incognita (MiASB) based on the nematode genomics prediction. By soaking in the MiASB dsRNA solution, the hatching of RNAi treated eggs was reduced by 60% compared to negative control and by 64% compared to untreated control. Mortality of RNAi treated second stage juvenile (J2) was 8.6 times higher than that of negative control and 26 times higher than the untreated control. Inoculating the RNAi treated egg masses and J2 to tomato seedlings showed the pathogencity was significantly reduced. For the RNAi treated egg masses, the amount of root galls on silence treated seedlings was reduced by 92% compared to that on the negative control seedlings, and reduced by 93% compared to that on untreated control seedlings. For the treated J2, the amount of root galls on silence treated seedlings was reduced by 83% and 86% compared to negative and untreated control seedlings, respectively. The study revealed the MiASB silence had a positive effect on prevention and control of root-knot nematode disease, and also showed that the MiASB may be involved in the pathogenesis of nematode, which provided new ideas and ways to the research of nematode pathology and nematode disease control.

Yonghong Huang; Mei Mei; Baoming Shen; Zhenchuan Mao; Bingyan Xie

2013-01-01

203

Rotations with Coastal Bermudagrass and Fallow for Management of Meloidogyne incognita and Soilborne Fungi on Vegetable Crops.  

Science.gov (United States)

The efficacy of fallow and coastal bermudagrass (Cynodon dactylon) as a rotation crop for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus cv. Emerald), squash (Cucurbita pepo cv. Dixie Hybrid), and sweet corn (Zea mays cv. Merit) was evaluated in a 3-year field trial. Numbers of M. incognita in the soil and root-gall indices were greater on okra and squash than sweet corn and declined over the years on vegetable crops following fallow and coastal bermudagrass sod. Fusarium oxysporum and Pythium spp. were isolated most frequently from soil and dying okra plants. Numbers of colony-forming units of soilborne fungi generally declined as the number of years in sod increased, but were not affected by coastal bermudagrass sod. Yields of okra following 2-year and 3-year sod and squash following 2-year sod were greater than those following fallow. Yield of sweet corn was not different following fallow and coastal bermudagrass sod. PMID:19277312

Johnson, A W; Burton, G W; Wilson, J P; Golden, A M

1995-12-01

204

Rotations with Coastal Bermudagrass and Fallow for Management of Meloidogyne incognita and Soilborne Fungi on Vegetable Crops.  

UK PubMed Central (United Kingdom)

The efficacy of fallow and coastal bermudagrass (Cynodon dactylon) as a rotation crop for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus cv. Emerald), squash (Cucurbita pepo cv. Dixie Hybrid), and sweet corn (Zea mays cv. Merit) was evaluated in a 3-year field trial. Numbers of M. incognita in the soil and root-gall indices were greater on okra and squash than sweet corn and declined over the years on vegetable crops following fallow and coastal bermudagrass sod. Fusarium oxysporum and Pythium spp. were isolated most frequently from soil and dying okra plants. Numbers of colony-forming units of soilborne fungi generally declined as the number of years in sod increased, but were not affected by coastal bermudagrass sod. Yields of okra following 2-year and 3-year sod and squash following 2-year sod were greater than those following fallow. Yield of sweet corn was not different following fallow and coastal bermudagrass sod.

Johnson AW; Burton GW; Wilson JP; Golden AM

1995-12-01

205

Transcriptional changes of the root-knot nematode Meloidogyne incognita in response to Arabidopsis thaliana root signals.  

UK PubMed Central (United Kingdom)

Root-knot nematodes are obligate parasites that invade roots and induce the formation of specialized feeding structures. Although physiological and molecular changes inside the root leading to feeding site formation have been studied, very little is known about the molecular events preceding root penetration by nematodes. In order to investigate the influence of root exudates on nematode gene expression before plant invasion and to identify new genes potentially involved in parasitism, sterile root exudates from the model plant Arabidopsis thaliana were produced and used to treat Meloidogyne incognita pre-parasitic second-stage juveniles. After confirming the activity of A. thaliana root exudates (ARE) on M. incognita stylet thrusting, six new candidate genes identified by cDNA-AFLP were confirmed by qRT-PCR as being differentially expressed after incubation for one hour with ARE. Using an in vitro inoculation method that focuses on the events preceding the root penetration, we show that five of these genes are differentially expressed within hours of nematode exposure to A. thaliana roots. We also show that these genes are up-regulated post nematode penetration during migration and feeding site initiation. This study demonstrates that preceding root invasion plant-parasitic nematodes are able to perceive root signals and to respond by changing their behaviour and gene expression.

Teillet A; Dybal K; Kerry BR; Miller AJ; Curtis RH; Hedden P

2013-01-01

206

Bioefficacy evaluation of controlled release formulations based on amphiphilic nano-polymer of carbofuran against Meloidogyne incognita infecting tomato.  

UK PubMed Central (United Kingdom)

In the present investigation, the bioefficacy of developed carbofuran formulations, with PEG-600 (7a, CP1) & PEG-900 (7b, CP2) @ 5, 10 and 20 ppm, along with commercial formulation of carbofuran 3G (CP0) were evaluated against the root-knot nematode, Meloidogyne incognita infecting tomato (cv. Pusa Ruby) in pot and field conditions. The bioefficacy data indicated that the formulations developed by utilizing polymers having PEG - 900 (7b) as hydrophilic segment were effective even at 14 days post inoculation (dpi) as evident from shoot and root length. Also, the reduction in penetration was found to be maximum with CP2 (3.6 - 4.6 J2s) at all concentrations compared to CP1 (6.6-16.4 J2s) and CP0 (29.3-32.6 J2s). Overall, CP2 was more effective in reducing the number of nematodes up to 14 days, compared to CP1 and CP0. Both the CR formulations (CP1 and CP2) in general significantly reduced the number of galls, when compared to CP0. However, under field conditions, lower concentrations (5, and 10 ppm) of CP2, were less effective in controlling the gall formation whereas, CP2 at 20 ppm, was most effective than other treatments. The study revealed that the developed CR formulations of carbofuran have the potential for effective management of M. incognita in tomato under field conditions.

Pankaj; Shakil NA; Kumar J; Singh MK; Singh K

2012-01-01

207

Transcriptional changes of the root-knot nematode Meloidogyne incognita in response to Arabidopsis thaliana root signals.  

Science.gov (United States)

Root-knot nematodes are obligate parasites that invade roots and induce the formation of specialized feeding structures. Although physiological and molecular changes inside the root leading to feeding site formation have been studied, very little is known about the molecular events preceding root penetration by nematodes. In order to investigate the influence of root exudates on nematode gene expression before plant invasion and to identify new genes potentially involved in parasitism, sterile root exudates from the model plant Arabidopsis thaliana were produced and used to treat Meloidogyne incognita pre-parasitic second-stage juveniles. After confirming the activity of A. thaliana root exudates (ARE) on M. incognita stylet thrusting, six new candidate genes identified by cDNA-AFLP were confirmed by qRT-PCR as being differentially expressed after incubation for one hour with ARE. Using an in vitro inoculation method that focuses on the events preceding the root penetration, we show that five of these genes are differentially expressed within hours of nematode exposure to A. thaliana roots. We also show that these genes are up-regulated post nematode penetration during migration and feeding site initiation. This study demonstrates that preceding root invasion plant-parasitic nematodes are able to perceive root signals and to respond by changing their behaviour and gene expression. PMID:23593446

Teillet, Alice; Dybal, Katarzyna; Kerry, Brian R; Miller, Anthony J; Curtis, Rosane H C; Hedden, Peter

2013-04-12

208

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

Directory of Open Access Journals (Sweden)

Full Text Available Meloidogyne incognita es un nematodo endoparásito sedentario, de penetración total y formador de nódulos radicales; tiene una amplia distribución geográfica y causa pérdidas agrícolas importantes. Recientemente se han utilizado abonos orgánicos y compuestos como la quitina en la supresión de plagas y enfermedades de plantas. El objetivo de esta investigación fue evaluar el efecto de la aplicación de vermicompost de estiércol bovino y su enriquecimiento con quitina, sobre la infección de M. incognita en plantas de tomate var. Hayslip bajo condiciones de invernadero. Para esto se inocularon las plantas con 5000 unidades de inóculo (huevos+juveniles en segundo estado) por maceta y se compararon con controles que fueron sembrados en suelo sin enmienda orgánica o quitina. La evaluación se llevó a cabo 60 días después y se midió el peso fresco aéreo y radical, peso seco aéreo, población total de nematodos en raíz y suelo, índice de nódulos radicales (INR), índice de masas de huevos (IMH), el factor de reproducción del nematodo (FR) y recuento de grupos funcionales (hongos, bacterias y actinomicetes). La adición al suelo de vermicompost provocó un incremento en las variables peso fresco y seco foliar y peso fresco radical: a mayor porcentaje de vermicompost, mayor incremento; así mismo, la aplicación del vermicompost redujo la cantidad del nematodo en raíz y en suelo. La aplicación de quitina acentuó estos resultados, obteniéndose el menor factor de reproducción de M. Incognita, con un valor de 3,76 para la dosis de 50% vermicompost+quitina, mientras que en el testigo este factor fue de 93,20. La aplicación de quitina como enmienda única solo afectó la población de hongos en el suelo, mientras que la de actinomicetes aumentó en los tratamientos enmendados.

Leida Castro; Lorena Flores; Lidieth Uribe

2011-01-01

209

Molecular and Morphological Characterization of an Unusual Meloidogyne arenaria Population from Traveler's Tree, Ravenala madagascariensis.  

UK PubMed Central (United Kingdom)

An unusual variant of Meloidogyne arenaria was discovered on roots of a traveler's tree (Ravenala madagascariensis) intended for display at a public arboretum in Pennsylvania. The population aroused curiosity by the lack of visible galling on the roots of the infected plant, and the female vulval region was typically surrounded by egg sacs. Most morphometrics of the population fit within the ranges reported for M. arenaria, with a mosaic of features in common with either M. platani or other tropical Meloidogyne spp. Molecular characterization included analysis of four loci. The mitochondrial sequence, extending from cytochrome oxidase II (COII) to the 16S (1RNA) gene, was nearly identical to another M. arenaria population and closely related to sequences from M. morocciensis and M. thailandica. The 28S D2-D3 expansion segment was most similar to those from M. arenaria, M. incognita and M. paranaensis, and the IGS-2 was most related to those from M. thailandica, M. arenaria and M. incognita. Analysis of partial Hsp90 genomic sequences revealed the greatest similarity to M. arenaria, M. thailandica and an Hsp90 haplotype from M. floridensis, and a composite sequence comprised of EST from M. arenaria. No morphological or molecular features clearly distinguished this population as a new species, and, when considered as a whole, the evidence points to its identification as M. arenaria.

Skantar A; Carta L; Handoo Z

2008-09-01

210

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  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 ? (more) ?C 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. Abstract in english 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 (more) 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.

Rocha, Fernando da Silva; Campos, Vicente P.; Souza, Ricardo Magela de

2004-12-01

211

Seleção de genótipos de aceroleira assistida por marcadores isoenzimáticos visando à resistência a Meloidogyne incognita raça 2/ Genotype selection of Barbados cherry using iso-enzymatic markers for resistance to Meloidogyne incognita race 2  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A cultura da aceroleira despertou um grande interesse do mercado consumidor, tendo em vista o alto teor de vitamina C (ácido ascórbico), que varia entre 1.325 a 2.250 mg por 100 mL de suco. Com a expansão da cultura, surgiram problemas fitossanitários, entre os quais a infecção das raízes da aceroleira por nematóides. Os produtos químicos utilizados no controle dos nematóides são agressivos ao meio ambiente, e a seleção de genótipos resistentes e tolerantes (more) constitui-se na melhor alternativa para a solução do problema. O trabalho foi desenvolvido em casa de vegetação com 18 genótipos de aceroleira, com o objetivo de encontrar genótipos resistentes e tolerantes a Meloidogyne incognita raça 2 assistida por marcadores isoenzimáticos, para indicar plantas destinadas a porta-enxerto. A avaliação foi realizada 60 dias após a inoculação mediante análise das variáveis: número de ovos por planta e por grama de raiz, índice de galhas e massa de ovos, biomassa fresca relativa do sistema radicular e biomassa fresca relativa da parte aérea. Os resultados permitiram identificar o genótipo 023-CMF como menos suscetível, e os genótipos 027-CMF e 035-CMF, como mais suscetíveis. Estudos realizados através da eletroforese isoenzimática com os sistemas ? esterase, fosfatase ácida e peroxidase, 20; 40 e 60 dias após a inoculação com ovos de M. incognita raça 2, possibilitaram relacionar a expressão de proteínas com a suscetibilidade. Os genótipos mais próximos geneticamente, com índice de similaridade 0,941, foram 027-CMF e 026-CMF, 046-CMF e 026-CMF, e 041-CMF e 026-CMF. O menor índice de similaridade genética (0,115) foi observado entre os genótipos 002-SPE e 036-CMF. Abstract in english The culture of the Barbados cherry has increased great interest in the consuming market, in view of high levels of vitamin C, each 100ml of juice has contents of 1,325mg / 2,250mg of vitamin C (Ascorbic acid).With the increase of the plantations phytosanitary problems appeared, such as infection of the roots for nematodes. The utilisation of chemical products for controlling nematodes is unsafe for the environment, therefore the election of resistant and tolerant genotype (more) s is the best solution for this problem. The work was developed in greenhouse, with eighteen genotypes of Barbados cherry aiming to find resistant genotypes to Meloidogyne incognita race 2, marked with iso-enzymatic markers, indicating plants destined for rootstock. Sixty days after the inoculation, the evaluation of the variables began: amount of eggs per plant and weight of root, index of galls and eggs mass, fresh biomass relative to the root systems, fresh biomass relative to the aerial part. The results permitted to identify the genotype 023-CMF as the less susceptible and the genotypes 027-CMF and 035-CMF as the most susceptible. Studies carried out through iso-enzymatic electrophoresis with the systems ? -esterase, acid phosphatase and peroxidase. Twenty, forty and sixty days after the inoculation with eggs of M. incognita race2, made it possible to relate the expression of proteins with the susceptibility. The genotypes genetically closer, with index of similarity 0.941 are: 027-CMF and 026-CMF, 046-CMF and 026-CMF and 041-CMF and 026-CMF. The lesser indices of genetic similarity 0.115 are: genotypes 002-SPE and 036-CMF.

Rossiter, Jackeline Gadé de Araujo; Musser, Rosimar dos Santos; Martins, Luiza Suely Semen; Pedrosa, Elvira Maria Regis; Medeiros, Jeane Emilli de

2008-12-01

212

Seleção de genótipos de aceroleira assistida por marcadores isoenzimáticos visando à resistência a Meloidogyne incognita raça 2 Genotype selection of Barbados cherry using iso-enzymatic markers for resistance to Meloidogyne incognita race 2  

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Full Text Available A cultura da aceroleira despertou um grande interesse do mercado consumidor, tendo em vista o alto teor de vitamina C (ácido ascórbico), que varia entre 1.325 a 2.250 mg por 100 mL de suco. Com a expansão da cultura, surgiram problemas fitossanitários, entre os quais a infecção das raízes da aceroleira por nematóides. Os produtos químicos utilizados no controle dos nematóides são agressivos ao meio ambiente, e a seleção de genótipos resistentes e tolerantes constitui-se na melhor alternativa para a solução do problema. O trabalho foi desenvolvido em casa de vegetação com 18 genótipos de aceroleira, com o objetivo de encontrar genótipos resistentes e tolerantes a Meloidogyne incognita raça 2 assistida por marcadores isoenzimáticos, para indicar plantas destinadas a porta-enxerto. A avaliação foi realizada 60 dias após a inoculação mediante análise das variáveis: número de ovos por planta e por grama de raiz, índice de galhas e massa de ovos, biomassa fresca relativa do sistema radicular e biomassa fresca relativa da parte aérea. Os resultados permitiram identificar o genótipo 023-CMF como menos suscetível, e os genótipos 027-CMF e 035-CMF, como mais suscetíveis. Estudos realizados através da eletroforese isoenzimática com os sistemas ? esterase, fosfatase ácida e peroxidase, 20; 40 e 60 dias após a inoculação com ovos de M. incognita raça 2, possibilitaram relacionar a expressão de proteínas com a suscetibilidade. Os genótipos mais próximos geneticamente, com índice de similaridade 0,941, foram 027-CMF e 026-CMF, 046-CMF e 026-CMF, e 041-CMF e 026-CMF. O menor índice de similaridade genética (0,115) foi observado entre os genótipos 002-SPE e 036-CMF.The culture of the Barbados cherry has increased great interest in the consuming market, in view of high levels of vitamin C, each 100ml of juice has contents of 1,325mg / 2,250mg of vitamin C (Ascorbic acid).With the increase of the plantations phytosanitary problems appeared, such as infection of the roots for nematodes. The utilisation of chemical products for controlling nematodes is unsafe for the environment, therefore the election of resistant and tolerant genotypes is the best solution for this problem. The work was developed in greenhouse, with eighteen genotypes of Barbados cherry aiming to find resistant genotypes to Meloidogyne incognita race 2, marked with iso-enzymatic markers, indicating plants destined for rootstock. Sixty days after the inoculation, the evaluation of the variables began: amount of eggs per plant and weight of root, index of galls and eggs mass, fresh biomass relative to the root systems, fresh biomass relative to the aerial part. The results permitted to identify the genotype 023-CMF as the less susceptible and the genotypes 027-CMF and 035-CMF as the most susceptible. Studies carried out through iso-enzymatic electrophoresis with the systems ? -esterase, acid phosphatase and peroxidase. Twenty, forty and sixty days after the inoculation with eggs of M. incognita race2, made it possible to relate the expression of proteins with the susceptibility. The genotypes genetically closer, with index of similarity 0.941 are: 027-CMF and 026-CMF, 046-CMF and 026-CMF and 041-CMF and 026-CMF. The lesser indices of genetic similarity 0.115 are: genotypes 002-SPE and 036-CMF.

Jackeline Gadé de Araujo Rossiter; Rosimar dos Santos Musser; Luiza Suely Semen Martins; Elvira Maria Regis Pedrosa; Jeane Emilli de Medeiros

2008-01-01

213

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

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Full Text Available The objective of this work was to evaluate the effect of grafting (onto Solanum torvum Sw.) on plant growth, yield and fruit quality of the Pala and Faselis eggplant (Solanum melongena L.) cultivars, grown in a soil infested with Verticillium dahliae Kleb. and Meloidogyne incognita, or in noninfested soil. Soil infestation decreased yield, plant height, final above-ground biomass, and also reduced fruit mean weight and shoot dry weight depending on cultivar or grafting. Grafting decreased fruit oxalic acid and the soluble solid contents, and increased mean fruit weight, depending on cultivar and soil infestation. Grafting also reduced the negative effects of the pathogens on disease index, plant height and shoot dry weight. Cultivar Pala was more vigorous than Faselis, and S. torvum was a vigorous rootstock. The combination of a vigorous rootstock with a weak cultivar (Faselis) is more profitable than that of a vigorous rootstock and a vigorous cultivar (Pala). Using S. torvum as a rootstock for cultivar Faselis, grown in soil infested with the pathogens, is most likely to be useful in conventional and low-input sustainable horticulture, since grafting increases protection against the pathogens, and reduces the losses in quality and yield.O objetivo deste trabalho foi avaliar o efeito sobre a altura de planta, a produção e a qualidade de frutos do enxerto das cultivares de beringela (Solanum melongena L.) Pala e Faselis em Solanum torvum Sw., quando cultivadas em solo infestado com Verticillium dahliae e Meloidogyne incognita ou em solo não infestado. A infestação do solo reduziu a produção, altura da planta, biomassa da parte aérea, massa média dos frutos, massa de matéria seca da parte aérea, conforme a cultivar utilizada e a enxertia. A enxertia reduziu os conteúdos de ácido oxálico e de sólidos solúveis e aumentou a massa média de frutos, conforme a cultivar ou a presença do patógeno no solo. A enxertia também reduziu o efeito negativo dos patógenos sobre o índice de doença, a altura de planta e a massa de matéria seca da parte aérea. A cultivar Pala foi mais vigorosa que a Faselis, e S. torvum foi um porta-enxerto vigoroso. A combinação 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, é provavelmente promissora na horticultura convencional e na horticultura sustentável de baixos insumos, pois a enxertia aumenta a proteção contra os patógenos, e reduz a perda de qualidade dos frutos e da produção.

Sebahattin Çürük; H. Y?ld?z Dasgan; Sedat Mansuro?lu; ?ener Kurt; Meltem Mazmano?lu; Özgür Antakl?; Gülcan Tarla

2009-01-01

214

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo deste trabalho foi avaliar o efeito sobre a altura de planta, a produção e a qualidade de frutos do enxerto das cultivares de beringela (Solanum melongena L.) Pala e Faselis em Solanum torvum Sw., quando cultivadas em solo infestado com Verticillium dahliae e Meloidogyne incognita ou em solo não infestado. A infestação do solo reduziu a produção, altura da planta, biomassa da parte aérea, massa média dos frutos, massa de matéria seca da parte aérea, (more) conforme a cultivar utilizada e a enxertia. A enxertia reduziu os conteúdos de ácido oxálico e de sólidos solúveis e aumentou a massa média de frutos, conforme a cultivar ou a presença do patógeno no solo. A enxertia também reduziu o efeito negativo dos patógenos sobre o índice de doença, a altura de planta e a massa de matéria seca da parte aérea. A cultivar Pala foi mais vigorosa que a Faselis, e S. torvum foi um porta-enxerto vigoroso. A combinação 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, é provavelmente promissora na horticultura convencional e na horticultura sustentável de baixos insumos, pois a enxertia aumenta a proteção contra os patógenos, e reduz a perda de qualidade dos frutos e da produção. Abstract in english 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. G (more) rafting 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.

Çürük, Sebahattin; Dasgan, H. Yı ldı z; Mansuroğ lu, Sedat; Kurt, Ş ener; Mazmanoğ lu, Meltem; Antaklı , Özgür; Tarla, Gülcan

2009-12-01

215

Reação de cultivares de algodoeiro a Meloidogyne incognita em condições de campo e casa de vegetação no estado de Mato Grosso Reaction of cotton genotypes to Meloidogyne incognita in field and greenhouse trials in Mato Grosso state, Brazil  

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Full Text Available Genótipos de algodoeiro, compreendendo cultivares e linhagens avançadas, foram avaliados no Estado de Mato Grosso quanto à reação a Meloidogyne incognita. Em dois experimentos de campo, foi avaliada a tolerância a esse nematóide mediante atribuição de notas, de acordo com sintomas externos exibidos pelas plantas. Um ensaio avaliou também a resistência ao parasita, mediante determinação do número de espécimes nas raízes de plantas amostradas nas parcelas. A resistência foi avaliada também em casa de vegetação, por meio da determinação do número de massas de ovos nas raízes e do fator de reprodução. Foram constatadas diferenças notáveis na reação dos 22 genótipos estudados, verificando-se a formação de grupos graduais de desempenho, tanto com respeito à resistência quanto à tolerância. Nas duas características, destacaram-se positivamente as cultivares IAC 25 RMD, IPR 140 e IPR JATAÍ, e negativamente, dentre outras, FIBERMAX 966, LDCV FREGO e FMT 703. A produção de algodão em caroço variou de 482 a 3087 g/parcela no experimento de Campo Verde, e de 1153 a 3151 g/parcela no de Primavera do Leste. As perdas na produção, nos genótipos mais afetados, foram de até 65% no primeiro experimento e de até 40% no segundo. Os dados de avaliação da resistência e da tolerância mostraram-se correlacionados, porém, os da tolerância, a julgar pelos coeficientes de variação e de correlação intra-classe, na análise da variância, mostraram-se mais precisos e de maior repetibilidade.Cotton genotypes, comprising cultivars and advanced lineages, were evaluated for tolerance and resistance to Meloidogyne incognita in Mato Grosso state, Brazil. Tolerance was evaluated in two field experiments, attributing scores according to external symptoms exhibited by plants, while resistance was studied in greenhouse and in one field trial, counting the number of egg masses or specimens on the roots, and the reproduction factor. Significant differences were observed among the 22 studied genotypes, concerning both resistance and tolerance, and graduated performance groups were established. The cultivars IAC 25 RMD, IPR 140 and IPR JATAI formed the most resistant/tolerant group, while FIBERMAX 966, LDCV FREGO, and FMT 703, among others, were situated in the most susceptible/intolerant ones. Cotton seed yield ranged from 482 to 3087 g/plot at Campo Verde and from 1153 to 3151 g/plot at Primavera do Leste. Yield losses, attributable to incidence of this nematode, were estimated at 65% and 40%, respectively, in these trials. Data related to resistance and to tolerance were correlated, however, and by taking into account coefficient of variation and intra-class correlation, from the analysis of variance, it could be seen that data relating to tolerance presented greater precision and repeatability.

Rafael Galbieri; Milton G. Fuzatto; Edivaldo Cia; Reginaldo R. Lüders; Andressa C.Z. Machado; Alberto F. Boldt

2009-01-01

216

A comparison of the FMRFamide-like peptide proteolytic activities of preparations from two plant-parasitic nematodes (Heterodera glycines and Meloidogyne incognita): possible targets for novel control.  

Science.gov (United States)

Proteolytic activities in extracts from the plant-parasitic nematodes Heterodera glycines and Meloidogyne incognita were examined for their abilities to digest three FRET-modified peptide substrates representing members of the large FMRFamide-like peptide (FLP) family in nematodes. Included were sequences distributed across all nematode species (KSAYMRFa and KHEYLRFa) and a sequence confined to a narrow range of plant-parasitic nematodes (KHEFVRFa). Species variations were observed among substrate affinities, reaction rates and effect of protease inhibitors. K m values for KHEYLRFa (1.48 ± 0.34 ?m) and KSAYMRFa (2.13 ± 0.24 ?m) in H. glycines were each lower (P< 0.05) than those for the same substrates in M. incognita (5.26 ± 1.30 ?m and 3.90 ± 0.61 ?m, respectively). The K m of KHEFVRFa was lower (P< 0.05) in M. incognita (5.83 ± 0.36 ?m) than in H. glycines (11.01 ± 1.26 ?m). Reaction rates (V max/min/?g) for KHEYLRFa were the same for both species, but KSAYMRFa and KHEFVRFa digestion rates were each nearly twofold higher (P< 0.05) in M. incognita than in H. glycines. Digestion of KSAYMRFa was strongly inhibited in both species by 4-(2-aminoethyl)-benzenesulfonyl-fluoride-HCl (AEBSF) and EDTA, but M. incognita was more sensitive (P< 0.05) to inhibition. AEBSF and EDTA (both at 1 mm) inhibited M. incognita activity 62.3% and 36.6% more, respectively, than H. glycines activity. Serine protease inhibition differed significantly (P< 0.05) between the two species. Maximum inhibition of M. incognita (76%) occurred at 1.85 mm AEBSF while maximum inhibition of H. glycines was 40% at 1.19 mm AEBSF. PMID:22310027

Masler, E P

2012-02-06

217

A comparison of the FMRFamide-like peptide proteolytic activities of preparations from two plant-parasitic nematodes (Heterodera glycines and Meloidogyne incognita): possible targets for novel control.  

UK PubMed Central (United Kingdom)

Proteolytic activities in extracts from the plant-parasitic nematodes Heterodera glycines and Meloidogyne incognita were examined for their abilities to digest three FRET-modified peptide substrates representing members of the large FMRFamide-like peptide (FLP) family in nematodes. Included were sequences distributed across all nematode species (KSAYMRFa and KHEYLRFa) and a sequence confined to a narrow range of plant-parasitic nematodes (KHEFVRFa). Species variations were observed among substrate affinities, reaction rates and effect of protease inhibitors. K m values for KHEYLRFa (1.48 ± 0.34 ?m) and KSAYMRFa (2.13 ± 0.24 ?m) in H. glycines were each lower (P< 0.05) than those for the same substrates in M. incognita (5.26 ± 1.30 ?m and 3.90 ± 0.61 ?m, respectively). The K m of KHEFVRFa was lower (P< 0.05) in M. incognita (5.83 ± 0.36 ?m) than in H. glycines (11.01 ± 1.26 ?m). Reaction rates (V max/min/?g) for KHEYLRFa were the same for both species, but KSAYMRFa and KHEFVRFa digestion rates were each nearly twofold higher (P< 0.05) in M. incognita than in H. glycines. Digestion of KSAYMRFa was strongly inhibited in both species by 4-(2-aminoethyl)-benzenesulfonyl-fluoride-HCl (AEBSF) and EDTA, but M. incognita was more sensitive (P< 0.05) to inhibition. AEBSF and EDTA (both at 1 mm) inhibited M. incognita activity 62.3% and 36.6% more, respectively, than H. glycines activity. Serine protease inhibition differed significantly (P< 0.05) between the two species. Maximum inhibition of M. incognita (76%) occurred at 1.85 mm AEBSF while maximum inhibition of H. glycines was 40% at 1.19 mm AEBSF.

Masler EP

2013-03-01

218

Host suitability and response of asparagus cultivars to meloidogyne species and races.  

Science.gov (United States)

The host-parasite relationships of asparagus and Meloidogyne spp. were examined under greenhouse and microplot conditions. Meloidogyne species and races differed greatly in their ability to reproduce on asparagus seedlings. Meloidogyne hapla generally failed to reproduce, and M. javanica, M. arenaria race 1, and M. incognita race 3 reproduced poorly, with a reproduction factor (Rf = final population/initial population) usually < 1.0. Only M. arenaria race 2 and M. incognita races 1 and 4 reproduced consistently on all asparagus cultivars tested (Rf typically 1-11). No effect of M. incognita race 4 on host growth was detected. Meloidogyne arenaria race 2 and M. incognita race 1 had slight negative effects (5-10%) on plant and root growth. PMID:19283211

Dudash, P J; Barker, K R

1992-03-01

219

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

International Nuclear Information System (INIS)

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

2002-01-01

220

Evaluation of the Effect of Ecologic on Root Knot Nematode, Meloidogyne incognita, and Tomato Plant, Lycopersicon esculenum  

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Full Text Available Nonchemical methods and strategies for nematode management including cultural methods and engineered measures have been recommended as an alternative to methyl bromide (a major soil fumigant), due to its role in the depletion of the ozone layer. Hence, an international agreement has recently been reached calling for its reduced consumption and complete phasing out. This present research evaluates the potential of Ecologic, a biological, marine shell meal chitin material, as a soil amendment management agent for root knot nematode, Meloidogyne incognita, control, and its effect on the growth of Floradel tomato plant, Lycopersicon esculentum. To accomplish this goal, studies were conducted during which, experimental pots were set up in greenhouse environments using sterilized soil inoculated with 5,000 root-knot eggs per 1500 g soil. There were 4 treatments and 5 replications. Treatments were: No chitin; 50 g chitin; 100 g chitin; and 200 g chitin. A two-week wait period following Ecologic amendment preceded Floradel tomato planting to allow breakdown of the chitin material into the soil. Fresh and dry weights of shoot and root materials were taken as growth end-points. A statistically significant difference (p ≤ 0.05) was obtained with regard to the growth rate of L. esculentum at 100 g chitin treatment compared to the control with no chitin. Mean fresh weights of Floradel tomato were 78.0 ± 22.3g, 81.0 ± 20.3g, 109.0 ± 25.4g and 102.0 ± 33.3g at 0, 50, 100 and 200g chitin, respectively. The analysis of root knot nematode concentrations indicated a substantial effect on reproduction rate associated with chitin amendment. Study results showed a significant decrease in both root knot nematode eggs and juveniles (J2) at 100g and 200g Ecologic chitin levels, however, an increase in nematode concentrations was recorded at the 50g Ecologic chitin level (p ≤ 0.05). The mean amounts of J2 population, as expressed per 1500cm3 soil, were 49,933 ± 38,819, 86,050 ± 25248, 103 ± 133 and 103 ± 133 for 0, 50, 100 and 200g chitin, respectively. Similarly, the mean numbers of root knot nematode eggs (per 1500cm3 of soil) were 40,759 ± 36,712, 66,048 ± 39,730, 9,904 ± 16,591 and 9,257 ± 17,204. Root gall rating was also significantly lower (p ≤ 0.05) at the 100g and 200g chitin levels compared to the control. Percent gall ratings were 3.3 ± 1.0%, 3.2 ± 1.0%, 1.0 ± 0.5%, and 1.0% ± 0.6% for amendment levels of 0, 50, 100, and 200g chitin, respectively.

Debora C. Ladner; Paul B. Tchounwou; Gary W. Lawrence

2008-01-01

 
 
 
 
221

Morphological Comparison of Second-Stage Juveniles of Six Populations of Meloidogyne hapla by SEM.  

UK PubMed Central (United Kingdom)

External morphology of second-stage juveniles of six populations of Meloidogyne hapla, hclonging to two cytological races (A and B), and one population each of M. arenaria, M. incognita, and M. javanica was compared by scanning electron microscopy (SEM). Race A of M. hapla included three facultatively parthenogenetic populations with haploid chromosome numbers of 15. 16, and 17; race B consisted of three mitotically parthenogenetic populations with somalic chromosome numhers of 45, 45, and 48. The mitotically parthenogenetic populations of M. arenaria, M. incognita, and M. javanica had 54, 41-43, and 44 chromosomes, respectively. Observations were made on head structures, lateral field, excretory pore, anal opening, and tail. Head morphology, including shape and proportion of labial disc and lips, expression of labial and cephalic sensilla, and markings on head region, was distinctly different for each species. M. hapla populations of race A were distinct from each other but showed much intrapopulatiou variation in head morphology. Populations of race B were different from those of race A and were very stable and quite similar in head morphology. Considerable inter- and intrapopulatiou variation made the structure of the lateral field, excretory pore, anal opening, and tail of little value in distinguishing species or populations. The results are discussed in relation to earlier SEM observations on the genus Helerodera.

Eisenback JD; Hirschmann H

1979-01-01

222

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

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Full Text Available 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.

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

2012-01-01

223

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

UK PubMed Central (United Kingdom)

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.

Babu RO; Moorkoth D; Azeez S; Eapen SJ

2012-01-01

224

Efecto in vitro de concentraciones del NEMACID® sobre huevos y juveniles de Meloidogyne incognita (Kofoid y White) Chitwood/ In vitro effect of different concentrations of NEMACID® on eggs and juveniles of Meloidogyne incognita (Kofoid and White) Chitwood  

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Full Text Available Abstract in spanish Para el manejo de nematodos, se desarrolló en Cuba el producto NEMACID®, que posee como ingrediente activo metabolitos obtenidos a partir de los efluentes de la fermentación líquida de Lecanicillium lecanii (Zare & Gams) formulado con sulfato de amonio. El objetivo de este ensayo fue determinar el efecto del NEMACID® sobre los huevos y juveniles (J2) de Meloidogyne incognita (Kofoid y White) Chitwood. En el ensayo se utilizaron como controles agua destilada, sulfato (more) de amonio ((NH4)2SO4; 1,69 mg.ml-1) y Dazomet (1g.1000ml-1); y se evaluaron cinco concentraciones de NEMACID® (18,75; 3,75; 1,875; 0, 1875 y 0,01875mg.ml-1). Los valores de LC50 y LC90, se calcularon usando el método Probit. Las evaluaciones se llevaron a cabo a las 24 horas, contabilizándose el número de J2 inmóviles y huevos no eclosionados del total. Los resultados corroboraron la acción nematicida del producto que provocó el colapso del contenido interno de los juveniles y resultó imposible su recuperación posterior. El NEMACID® a la concentración de 18,75 mg.ml-1 produjo mayor efectividad sobre la eclosión de los huevos y mortalidad de los juveniles que el Dazomet (control). El sulfato de amonio, producto que acompaña al hongo en el proceso de fermentación y forma parte de la formulación final del NEMACID®, no produjo afectación a huevos y juveniles. Las concentraciones de NEMACID® de 3,75 mg.ml-1 e inferiores no resultaron satisfactorias en el tratamiento de los huevos, donde el porcentaje de inhibición de la eclosión de los mismos estuvo por debajo del 50. Mientras que en juveniles, la concentración de 3,75 mg.ml-1 del producto ocasionó mortalidad por encima del 70%, sin diferencia significativa con el producto Dazomet. Abstract in english NEMACID® was developed in Cuba for root knot nematode management. This product contains the effluents from liquid fermentation of Lecanicillium lecani (Zare and Gams) as active ingredient, and is formulated with ammonium sulfate. The objective of this test was to determine the effect of NEMACID® on eggs and juveniles (J2) of Meloidogyne incognita (Kofoid and White) Chitwood. In the test, five concentrations of NEMACID® (18,75; 3,75; 1,875; 0,1875 y 0,01875mg.ml-1) were (more) evaluated using distilled water, ammonium sulfate ((NH4)2SO4; 1,69mg.ml-1) and Dazomet (1g.1000ml-1) as controls. The CL50 and CL90 were calculated using Probit analysis. The evaluations were done at 24h, when the total number of non mobile juveniles and non hatched eggs from the total were counted. The result corroborated the nematicide action of the product by producing the collapse of the internal content in juveniles with an impossible recovery. NEMACID® at a concentration of 18,75 mg. ml-1 showed a higher effect on egg hatching and juvenile mortality than Dazomet (control). The ammonium sulfate, a product accompanying the fungus in the fermentation process as part of the final formulation of NEMACID®, did not affect eggs or juveniles. Concentrations of NEMACID® equal to 3,75mg.ml-1 or lower did not affect the eggs, with a percentage of hatching inhibition below 50%. Meanwhile, in juveniles, the concentration of 3.75mg.ml-1 caused a mortality over 70%, without significant differences with Dazomet.

Guevara, Yusmila; Gómez, Eulalia; Pino, Oriela; Rodríguez, Y; Miranda, Ileana; Enrique, R; Rodríguez, Mayra G

2013-04-01

225

Reação de cultivares de algodoeiro a Meloidogyne incognita em condições de campo e casa de vegetação no estado de Mato Grosso/ Reaction of cotton genotypes to Meloidogyne incognita in field and greenhouse trials in Mato Grosso state, Brazil  

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Full Text Available Abstract in portuguese Genótipos de algodoeiro, compreendendo cultivares e linhagens avançadas, foram avaliados no Estado de Mato Grosso quanto à reação a Meloidogyne incognita. Em dois experimentos de campo, foi avaliada a tolerância a esse nematóide mediante atribuição de notas, de acordo com sintomas externos exibidos pelas plantas. Um ensaio avaliou também a resistência ao parasita, mediante determinação do número de espécimes nas raízes de plantas amostradas nas parcelas. A (more) resistência foi avaliada também em casa de vegetação, por meio da determinação do número de massas de ovos nas raízes e do fator de reprodução. Foram constatadas diferenças notáveis na reação dos 22 genótipos estudados, verificando-se a formação de grupos graduais de desempenho, tanto com respeito à resistência quanto à tolerância. Nas duas características, destacaram-se positivamente as cultivares IAC 25 RMD, IPR 140 e IPR JATAÍ, e negativamente, dentre outras, FIBERMAX 966, LDCV FREGO e FMT 703. A produção de algodão em caroço variou de 482 a 3087 g/parcela no experimento de Campo Verde, e de 1153 a 3151 g/parcela no de Primavera do Leste. As perdas na produção, nos genótipos mais afetados, foram de até 65% no primeiro experimento e de até 40% no segundo. Os dados de avaliação da resistência e da tolerância mostraram-se correlacionados, porém, os da tolerância, a julgar pelos coeficientes de variação e de correlação intra-classe, na análise da variância, mostraram-se mais precisos e de maior repetibilidade. Abstract in english Cotton genotypes, comprising cultivars and advanced lineages, were evaluated for tolerance and resistance to Meloidogyne incognita in Mato Grosso state, Brazil. Tolerance was evaluated in two field experiments, attributing scores according to external symptoms exhibited by plants, while resistance was studied in greenhouse and in one field trial, counting the number of egg masses or specimens on the roots, and the reproduction factor. Significant differences were observed (more) among the 22 studied genotypes, concerning both resistance and tolerance, and graduated performance groups were established. The cultivars IAC 25 RMD, IPR 140 and IPR JATAI formed the most resistant/tolerant group, while FIBERMAX 966, LDCV FREGO, and FMT 703, among others, were situated in the most susceptible/intolerant ones. Cotton seed yield ranged from 482 to 3087 g/plot at Campo Verde and from 1153 to 3151 g/plot at Primavera do Leste. Yield losses, attributable to incidence of this nematode, were estimated at 65% and 40%, respectively, in these trials. Data related to resistance and to tolerance were correlated, however, and by taking into account coefficient of variation and intra-class correlation, from the analysis of variance, it could be seen that data relating to tolerance presented greater precision and repeatability.

Galbieri, Rafael; Fuzatto, Milton G.; Cia, Edivaldo; Lüders, Reginaldo R.; Machado, Andressa C.Z.; Boldt, Alberto F.

2009-02-01

226

Damage quantification and reaction of bean genotypes (Phaseolus vulgaris L.) to Meloidogyne incognita race 3 and M. javanica/ Quantificação de danos e reção de genótipos de feijoeiro (Phaseolus vulgaris L.) à Meloidogyne incognita raça 3 e M. javanica  

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Full Text Available Abstract in portuguese Avaliaram-se danos e os níveis de resistência de cultivares e acessos de feijoeiro-comum resgatados nas regiões Sul e Serrana do Estado do Espírito Santo ao parasitismo de M. incognita raça 3 e M. javanica em casa de vegetação. Foram testados quatro genótipos resgatados de feijoeiro ("FORT-10", "FORT-13", "FORT-16" e "FORT-19"), e mais 2 cultivares comerciais: "Pérola"; e "Aporé". O cultivar "Rico-23" foi incluído como padrão de suscetibilidade aos nematóides (more) e plantas não inoculadas constituíram a testemunha. Desta forma, o experimento foi conduzido em delineamento inteiramente casualizado em esquema fatorial 3 (tratamentos considerando nematóides) x 7 (genótipos e cultivares de feijoeiros), com 7 repetições. Os dados foram mensurados aos 50 dias após a inoculação das plantas. Para a quantificação de danos foram avaliadas: altura das plantas (ALT), número de nós (NOS), número de folhas trifolioladas (NFT), peso da matéria fresca (PMF) e da matéria seca (PMS) da parte aérea, peso de raiz (PR), número de nódulos radiculares (NOD) e população final (PF) de nematóides por sistema radicular. Não foram observadas diferenças significativas entre os efeitos causados por M. incognita e M. javanica, porém ambas as espécies apresentaram valores inferiores quanto à ALT, NOS, NFT, PR, PMF e PMS em relação às testemunhas. Em relação aos níveis de resistência dos feijoeiros a M. incognita os feijoeiros "FORT-10", "FORT-13", "Aporé" e "FORT-16" comportaram-se como moderadamente resistente, as cultivares "Rico 23" e "Pérola" como pouco resistente e o genótipo "FORT-19" como altamente suscetível. Quando parasitados por M. javanica, os feijoeiros "FORT-19", "Rico 23", "FORT-16" e "FORT-13" foram pouco resistentes, "Pérola" e "Aporé" suscetíveis e "FORT-10" altamente suscetíveis. Abstract in english The damage and the resistance levels of cultivars and accessions of common beans rescued in the South and mountain regions of Espírito Santo State, Brazil, to M. incognita race 3 and M. javanica parasitism were evaluated under a greenhouse. Four rescued bean genotypes ("FORT-10", "FORT-13", "FORT-16" and "FORT-19") and 2 commercial cultivars: "Pérola", and "Aporé", were tested. The cultivar "Rico-23" was included as standard of susceptibility to nematodes and non-inocu (more) lated plants constituted the control. Thus, the experiment was carried out in a completely randomized design in 3 (treatments considering nematodes) x 7 (genotypes and bean cultivars) factorial arrangement, with 7 replicates. Data were measured at 50 days after plant inoculation. For damage quantification, the following variables were evaluated: plant height (PHE), number of nodes (NNO), number of trifoliate leaves (NRT), fresh matter weight (FWE) and dry matter weight (DWE) of shoots, root weight (RWE), number of root nodules (NRO) and final population (FPO) of nematodes per root system. There were no significant differences between the effects caused by M. incognita and M. javanica, but both species showed inferior values of PHE, NNO, NRT, RWE, FWE and DWE compared to controls. Concerning the levels of resistance of bean plants to M. incognita, the genotypes "FORT-10", "FORT-13", "Aporé" and "FORT-16" behaved as moderately resistant, the cultivars "Rico 23" and "Pérola" low resistant, and the genotype "FORT-19" as highly susceptible. When parasitized by M. javanica, the beans "FORT-19", "Rico-23", "FORT-16" and "FORT-13" were low resistant, "Pérola" and "Aporé" susceptible and "FORT-10" highly susceptible.

Santos, Leonardo Nazário Silva dos; Alves, Fábio Ramos; Belan, Leônidas Leoni; Cabral, Pablo Diego Silva; Matta, Frederico de Pina; Jesus Junior, Waldir Cintra de; Moraes, Willian Bucker de

2012-03-01

227

Effect of Crop Rotation on Meloidogyne spp. and Pratylenchus spp. Populations in Strawberry Fields in Taiwan.  

Science.gov (United States)

Changes in population levels of Meloidogyne hapla, M. incognita, Pratylenchus coffeae, and P. penetrans were studied in 12 strawberry fields in the Dahu region of Taiwan. Ten potential rotation crops and two cultural practices were evaluated for their effect on nematode populations and influence on strawberry yield. Rotation with rice or taro and the cultural practice of flooding and bare fallowing for four months were found to reduce nematode soil populations to two or fewer nematodes per 100 ml soil. Average strawberry yields increased between 2.4% to 6.3% following taro compared to the bare fallow treatment. Corn suppressed M. incognita and M. hapla populations and resulted in an increased in strawberry yield compared to bare fallow. Other phytopathogens also present in these fields limited taro as the rotation choice for nematode management. Results of this research and economic analysis of the input requirements for various rotation crops, corn and bare fallow were recommended as the most appropriate rotation strategies for nematode management in strawberry in this region. PMID:19259538

Chen, P; Tsay, T T

2006-09-01

228

Effect of Three Plant Residues and Chicken Manure used as Biofumigants at Three Temperatures on Meloidogyne incognita Infestation of Tomato in Greenhouse Experiments.  

Science.gov (United States)

Plant residues of broccoli, melon, and tomato with or without addition of chicken manure were used as biofumigants in two pot experiments with Meloidogyne incognita-infested soils. The efficacy of these biofumigants in controlling M. incognita infestation in susceptible tomato bio-assay plants was studied at soil temperatures of 20 masculine, 25 masculine, and 30 masculineC. None of the plant residues was effective at 20 masculineC, and broccoli was more effective than tomato or melon at 25 masculineC. At 30 masculineC all three plant residues reduced M. incognita infestation of tomato to very low levels. Chicken manure was effective in one of two experiments at 20 masculineC, and at 25 masculineC enhanced the efficacy of tomato and melon residue in one of two experiments. At 30 masculineC chicken manure was equally effective as the three plant residues but did not further decrease infestation levels in plant residue amended soils. It is concluded that biofumigation to control M. incognita is unlikely to be effective under cool conditions, that at soil temperatures around 25 masculineC broccoli is more effective than melon and tomato, and that the addition of chicken manure at this soil temperature may enhance the efficacy. At high soil temperatures, of approximately 30 masculineC, the biofumigant source seems of minor importance as strong reductions in tomato infestation by M. incognita were achieved by addition of each of the three plant residues as well as by addition of chicken manure. PMID:19262896

López-Pérez, Jose-Antonio; Roubtsova, Tatiana; Ploeg, Antoon

2005-12-01

229

Suppression of the root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] on tomato by dual inoculation with arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria.  

Science.gov (United States)

Arbuscular mycorrhizal (AM) fungi and plant growth-promoting rhizobacteria (PGPR) have potential for the biocontrol of soil-borne diseases. The objectives of this study were to quantify the interactions between AM fungi [Glomus versiforme (Karsten) Berch and Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe] and PGPR [Bacillus polymyxa (Prazmowski) Mace and Bacillus sp.] during colonization of roots and rhizosphere of tomato (Lycopersicon esculentum Mill) plants (cultivar Jinguan), and to determine their combined effects on the root-knot nematode, Meloidogyne incognita, and on tomato growth. Three greenhouse experiments were conducted. PGPR increased colonization of roots by AM fungi, and AM fungi increased numbers of PGPR in the rhizosphere. Dual inoculations of AM fungi plus PGPR provided greater control of M. incognita and greater promotion of plant growth than single inoculations, and the best combination was G. mosseae plus Bacillus sp. The results indicate that specific AM fungi and PGPR can stimulate each other and that specific combinations of AM fungi and PGPR can interact to suppress M. incognita and disease development. PMID:21755407

Liu, Runjin; Dai, Mei; Wu, Xia; Li, Min; Liu, Xingzhong

2011-07-14

230

Suppression of the root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] on tomato by dual inoculation with arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria.  

UK PubMed Central (United Kingdom)

Arbuscular mycorrhizal (AM) fungi and plant growth-promoting rhizobacteria (PGPR) have potential for the biocontrol of soil-borne diseases. The objectives of this study were to quantify the interactions between AM fungi [Glomus versiforme (Karsten) Berch and Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe] and PGPR [Bacillus polymyxa (Prazmowski) Mace and Bacillus sp.] during colonization of roots and rhizosphere of tomato (Lycopersicon esculentum Mill) plants (cultivar Jinguan), and to determine their combined effects on the root-knot nematode, Meloidogyne incognita, and on tomato growth. Three greenhouse experiments were conducted. PGPR increased colonization of roots by AM fungi, and AM fungi increased numbers of PGPR in the rhizosphere. Dual inoculations of AM fungi plus PGPR provided greater control of M. incognita and greater promotion of plant growth than single inoculations, and the best combination was G. mosseae plus Bacillus sp. The results indicate that specific AM fungi and PGPR can stimulate each other and that specific combinations of AM fungi and PGPR can interact to suppress M. incognita and disease development.

Liu R; Dai M; Wu X; Li M; Liu X

2012-05-01

231

Field Evaluation of Yield and Resistances of Local and Improved Sweet Potato (Ipomoeabatatas (L) Lam) Accessions to Cylas puncticollis and Meloidogyne incognita inSoutheastern Nigeria  

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Full Text Available Aim of the study was to evaluate local and improved accessions of sweet potato for resistances to Cylas puncticollis and Meloidogyne incognita and identify suitable ones for incorporation in breeding programmes for the production of genetically resistant and high yielding varieties. The experiment was conducted at the University of Uyo, Teaching and Research Farm located at Use Offot-Uyo, Southeastern Nigeria and laid out in a randomized complete block design, with three replications. Eighteen sweet potato accessions were studied, comprising 13 local accessions, namely: E5, B6, E3, B26, B2, E11, E6, E17, B21, E14, E7, B23, E10 and five IITA improved and recommended varieties (TIS 87/0087, TIS 8441, TIS 8164, TIS 2532 and TIS 86/0356) for southeastern Nigeria. Three of the IITA improved and recommended varieties (TIS 86/0356, TIS 8164 and TIS 87/0087 had higher number of root tubers per plot and higher root tuber yield per hectare than the local accessions, while eight of the local accessions indicated high resistances to Cylas puncticollis, namely: B6, B2, E17, B21, E14, E7, B23 and E10 and Meloidogyne incognita, namely: B6, E3, B26, B21, E14, E7, B23 and E10. The local accessions with high root tuber yields and very high resistances to C. puncticollis and M. incognita (B6, B21 and E10) could be incorporated in breeding programmes involving TIS 87/0087, TIS 8164, TIS 2532 and TIS 86/0356 for the production of hybrid varieties with higher yields and resistances to the pests in southeastern Nigeria.

Emmanuel E. Bassey

2012-01-01

232

Morphological and Morphometrical Characterization of Meloidogyne incognita from Different Host Plants in Four Districts of Punjab, India.  

Science.gov (United States)

The population of M. incognita, the root knot nematode (RKN) was found infesting five different host plants (okra, banana, sunflower, bottle gourd, and brinjal) out of 24 examined from four districts of Punjab, India (Gurdaspur, Ludhiana, Patiala, and Hoshiarpur). Morphological and morphometrical characterization indicated that in the case of mature female, the characters of body length and width, neck length, ratio 'a', anus to tail terminus (ATT), interphasmid distance (IPD), and perineal pattern were recorded as stable characters. These taxonomic characters can be reliable for identification. All characters of second-stage juvenile (J2) such as body length, stylet length, head to median bulb length (H-MB), distance from median bulb to excretory pore (MB-EP), tail length, anal body width (ABW), and ratios C and C' were highly variable. Analysis of interpopulation morphometric characters of mature female of M. incognita, namely, body length, width, and ratio 'a' were moderately variable characters (CV 0.26% to 20%) and stylet length, neck length, length of median bulb (LMB), and width of median bulb (WMB) were highly variable (CV 1.0% to 36.1%). In the perineal pattern, the two characters ATT and IPD were moderately variable (CV 8.8% to 17.6%) and two characters, anus to vulval slit (AVS) and length of vulval slit (LVS), were highly variable (CV 2.1% to 40.5%). In J2, body length, stylet length, H-MB, MB-EP, ABW, tail length, ratios C, and C' were highly variable characters (CV > 12%). PMID:23833327

Kaur, Harpreet; Attri, Rajni

2013-06-01

233

Morphological and Morphometrical Characterization of Meloidogyne incognita from Different Host Plants in Four Districts of Punjab, India.  

UK PubMed Central (United Kingdom)

The population of M. incognita, the root knot nematode (RKN) was found infesting five different host plants (okra, banana, sunflower, bottle gourd, and brinjal) out of 24 examined from four districts of Punjab, India (Gurdaspur, Ludhiana, Patiala, and Hoshiarpur). Morphological and morphometrical characterization indicated that in the case of mature female, the characters of body length and width, neck length, ratio 'a', anus to tail terminus (ATT), interphasmid distance (IPD), and perineal pattern were recorded as stable characters. These taxonomic characters can be reliable for identification. All characters of second-stage juvenile (J2) such as body length, stylet length, head to median bulb length (H-MB), distance from median bulb to excretory pore (MB-EP), tail length, anal body width (ABW), and ratios C and C' were highly variable. Analysis of interpopulation morphometric characters of mature female of M. incognita, namely, body length, width, and ratio 'a' were moderately variable characters (CV 0.26% to 20%) and stylet length, neck length, length of median bulb (LMB), and width of median bulb (WMB) were highly variable (CV 1.0% to 36.1%). In the perineal pattern, the two characters ATT and IPD were moderately variable (CV 8.8% to 17.6%) and two characters, anus to vulval slit (AVS) and length of vulval slit (LVS), were highly variable (CV 2.1% to 40.5%). In J2, body length, stylet length, H-MB, MB-EP, ABW, tail length, ratios C, and C' were highly variable characters (CV > 12%).

Kaur H; Attri R

2013-06-01

234

Mi-1-Mediated Resistance to Meloidogyne incognita in Tomato May Not Rely on Ethylene but Hormone Perception through ETR3 Participates in Limiting Nematode Infection in a Susceptible Host  

Science.gov (United States)

Root-knot nematodes, Meloidogyne spp., are important pests of tomato (Solanum lycopersicum) and resistance to the three most prevalent species of this genus, including Meloidogyne incognita, is mediated by the Mi-1 gene. Mi-1 encodes a nucleotide binding (NB) leucine-rich repeat (LRR) resistance (R) protein. Ethylene (ET) is required for the resistance mediated by a subset of NB-LRR proteins and its role in Mi-1-mediated nematode resistance has not been characterized. Infection of tomato roots with M. incognita differentially induces ET biosynthetic genes in both compatible and incompatible interactions. Analyzing the expression of members of the ET biosynthetic gene families ACC synthase (ACS) and ACC oxidase (ACO), in both compatible and incompatible interactions, shows differences in amplitude and temporal expression of both ACS and ACO genes in these two interactions. Since ET can promote both resistance and susceptibility against microbial pathogens in tomato, we investigated the role of ET in Mi-1-mediated resistance to M. incognita using both genetic and pharmacological approaches. Impairing ET biosynthesis or perception using virus-induced gene silencing (VIGS), the ET-insensitive Never ripe (Nr) mutant, or 1-methylcyclopropene (MCP) treatment, did not attenuate Mi-1-mediated resistance to M. incognita. However, Nr plants compromised in ET perception showed enhanced susceptibility to M. incognita indicating a role for ETR3 in basal resistance to root-knot nematodes.

Jhaveri, Teraneh Z.; Kaloshian, Isgouhi

2013-01-01

235

Mi-1-mediated resistance to Meloidogyne incognita in tomato may not rely on ethylene but hormone perception through ETR3 participates in limiting nematode infection in a susceptible host.  

Science.gov (United States)

Root-knot nematodes, Meloidogyne spp., are important pests of tomato (Solanum lycopersicum) and resistance to the three most prevalent species of this genus, including Meloidogyne incognita, is mediated by the Mi-1 gene. Mi-1 encodes a nucleotide binding (NB) leucine-rich repeat (LRR) resistance (R) protein. Ethylene (ET) is required for the resistance mediated by a subset of NB-LRR proteins and its role in Mi-1-mediated nematode resistance has not been characterized. Infection of tomato roots with M. incognita differentially induces ET biosynthetic genes in both compatible and incompatible interactions. Analyzing the expression of members of the ET biosynthetic gene families ACC synthase (ACS) and ACC oxidase (ACO), in both compatible and incompatible interactions, shows differences in amplitude and temporal expression of both ACS and ACO genes in these two interactions. Since ET can promote both resistance and susceptibility against microbial pathogens in tomato, we investigated the role of ET in Mi-1-mediated resistance to M. incognita using both genetic and pharmacological approaches. Impairing ET biosynthesis or perception using virus-induced gene silencing (VIGS), the ET-insensitive Never ripe (Nr) mutant, or 1-methylcyclopropene (MCP) treatment, did not attenuate Mi-1-mediated resistance to M. incognita. However, Nr plants compromised in ET perception showed enhanced susceptibility to M. incognita indicating a role for ETR3 in basal resistance to root-knot nematodes. PMID:23717408

Mantelin, Sophie; Bhattarai, Kishor K; Jhaveri, Teraneh Z; Kaloshian, Isgouhi

2013-05-23

236

Mi-1-mediated resistance to Meloidogyne incognita in tomato may not rely on ethylene but hormone perception through ETR3 participates in limiting nematode infection in a susceptible host.  

UK PubMed Central (United Kingdom)

Root-knot nematodes, Meloidogyne spp., are important pests of tomato (Solanum lycopersicum) and resistance to the three most prevalent species of this genus, including Meloidogyne incognita, is mediated by the Mi-1 gene. Mi-1 encodes a nucleotide binding (NB) leucine-rich repeat (LRR) resistance (R) protein. Ethylene (ET) is required for the resistance mediated by a subset of NB-LRR proteins and its role in Mi-1-mediated nematode resistance has not been characterized. Infection of tomato roots with M. incognita differentially induces ET biosynthetic genes in both compatible and incompatible interactions. Analyzing the expression of members of the ET biosynthetic gene families ACC synthase (ACS) and ACC oxidase (ACO), in both compatible and incompatible interactions, shows differences in amplitude and temporal expression of both ACS and ACO genes in these two interactions. Since ET can promote both resistance and susceptibility against microbial pathogens in tomato, we investigated the role of ET in Mi-1-mediated resistance to M. incognita using both genetic and pharmacological approaches. Impairing ET biosynthesis or perception using virus-induced gene silencing (VIGS), the ET-insensitive Never ripe (Nr) mutant, or 1-methylcyclopropene (MCP) treatment, did not attenuate Mi-1-mediated resistance to M. incognita. However, Nr plants compromised in ET perception showed enhanced susceptibility to M. incognita indicating a role for ETR3 in basal resistance to root-knot nematodes.

Mantelin S; Bhattarai KK; Jhaveri TZ; Kaloshian I

2013-01-01

237

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  

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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.

A.O. Ogaraku

2008-01-01

238

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  

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Full Text Available 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 la flor, número de pétalos, longitud del pedicelo, longitud y ancho de los pétalos, forma de los granos de polen, diámetro ecuatorial del fruto, masa fresca, diámetro polar, perímetro, grosor del casco, longitud de la cavidad ocupada por las semillas y color de la pulpa. Los resultados obtenidos indicaron que existen diferencias entre las selecciones en cada uno de las variables analizadas, determinando que por las características del fruto y su tolerancia a Meloidogyne incognita se recomiendan a las selecciones P. guajava "AGROLUZ-43" y "AGROLUZ-21" para ser propagadas asexualmente e incluirlas en programas de mejoramiento genético.A morphological study was performed on seven selections of tolerant P. guajava, one susceptible selection and one selection P. friedrichsthalianum"Cas" resistant to the nematode Meloidogyne incognita. The vegetative materials were recollected in the Centro Frutícola del Zulia-CORPOZULIA in Mara municipality. Leaves, flowers and fruits in all the selections were collected for the study of shape, margin, color, length of the pedicel, width and length of the leaves, the with/length relation , number of veins, number of petals, width and length of the petals, flower diameter, shape of pollen grain; shape, diameter, perimeter, length and side of fruit, thickness of mesocarp, cavity of the seed and color of the mesocarp. The morphological study indicated that there are differences between all the selections studied for all the evaluated characteristics in this study. Considering the fruit characteristics and tolerance to nematode M. incognita, it is recommended that the selections P. guajava "AGROLUZ-43" and "AGROLUZ-21" be asexually propagated.

T Molero; J Molina; A Casassa-Padrón

2003-01-01

239

Morphological and Molecular Evaluation of a Meloidogyne hapla Population Damaging Coffee (Coffea arabica) in Maui, Hawaii.  

Science.gov (United States)

An unusual population of Meloidogyne hapla, earlier thought to be an undescribed species, was found causing large galls, without adventitious roots, and substantial damage to coffee in Maui, Hawaii. Only in Brazil had similar damage to coffee been reported by this species. Unlike M. exigua from South and Central America, this population reproduced well on coffee cv. Mokka and M. incognita-susceptible tomato but poorly on tomato with the Mi resistance gene. Characterization included SEM images, esterase isozymes, and five DNA sequences: i) the D3 segment of the large subunit (LSU-D3 or 28S) rDNA, ii) internal transcribed spacer (ITS-1) rDNA, iii) intergenic spacer (IGS) rDNA, iv) the mitochondrial interval from cytochrome oxidase (CO II) to 16S mtDNA, and v) the nuclear gene Hsp90. Sequences for ITS-1, IGS, and COII were similar to other M. hapla populations, but within species ITS-1 variability was not less than among species. One LSU-D3 haplotype was similar to a previously analyzed population with two minor haplotypes. Hsp90 exhibited some variation between Maryland and Hawaiian populations distinct from other species. Females were narrow with wide vulval slits, large interphasmidial distances, and more posterior excretory pores; 20% of perineal patterns had atypical perivulval lines. Males had a low b ratio (<12 microm). Juveniles had a short distance between stylet and dorsal gland orifice. Juvenile body length was short (<355 microm) and was different between summer and winter populations. PMID:19262853

Handoo, Z A; Skantar, A M; Carta, L K; Schmitt, D P

2005-06-01

240

Biological Relationship of Meloidogyne hapla Populations to Alfalfa Cultivars  

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Greenhouse and growth chamber studies were established to determine if there are pathological and physiological differences among Meloidogyne hapla populations from California (CA), Nevada (NV), Utah (UT), and Wyoming (WY) on alfalfa cultivars classified as resistant or susceptible to root-knot nema...

Griffin, G. D.; Gray, F. A.

 
 
 
 
241

A gene encoding a peptide with similarity to the plant IDA signaling peptide (AtIDA) is expressed most abundantly in the root-knot nematode (Meloidogyne incognita) soon after root infection.  

Science.gov (United States)

Small peptides play important roles in intercellular signaling. Inflorescence deficient in abscission (ida) is an Arabidopsis mutant that does not abscise (shed) its flower petals. The IDA gene encodes a small, secreted peptide that putatively binds to two redundant receptor-like kinases (HAESA and HAESA-like2) that initiate a signal transduction pathway. We identified IDA-like (IDL) genes in the genomic sequence for Meloidogyne incognita and Meloidogyne hapla. No orthologous sequences were found in any other genus of nematodes. Transcript for both M. incognita and M. hapla IDLs were found in total RNA isolated from infected root systems of tomato, Solanum lycopersicum. Five and three prime RACE of RNA from M. incognita infected tomato roots revealed a sequence of 392 nt that includes a poly (A) tail of 39 nt. The open reading frame encodes a 47 aa protein with a putative 25 aa N-terminal signal peptide. Expression of MiIDL1 is very low in eggs and pre-parasitic J2 and rapidly increases in the first four days post inoculation (dpi) and then declines at approximately 14 dpi. A proposed role for the root-knot nematode IDL is discussed. PMID:23538028

Tucker, Mark L; Yang, Ronghui

2013-03-26

242

A gene encoding a peptide with similarity to the plant IDA signaling peptide (AtIDA) is expressed most abundantly in the root-knot nematode (Meloidogyne incognita) soon after root infection.  

UK PubMed Central (United Kingdom)

Small peptides play important roles in intercellular signaling. Inflorescence deficient in abscission (ida) is an Arabidopsis mutant that does not abscise (shed) its flower petals. The IDA gene encodes a small, secreted peptide that putatively binds to two redundant receptor-like kinases (HAESA and HAESA-like2) that initiate a signal transduction pathway. We identified IDA-like (IDL) genes in the genomic sequence for Meloidogyne incognita and Meloidogyne hapla. No orthologous sequences were found in any other genus of nematodes. Transcript for both M. incognita and M. hapla IDLs were found in total RNA isolated from infected root systems of tomato, Solanum lycopersicum. Five and three prime RACE of RNA from M. incognita infected tomato roots revealed a sequence of 392 nt that includes a poly (A) tail of 39 nt. The open reading frame encodes a 47 aa protein with a putative 25 aa N-terminal signal peptide. Expression of MiIDL1 is very low in eggs and pre-parasitic J2 and rapidly increases in the first four days post inoculation (dpi) and then declines at approximately 14 dpi. A proposed role for the root-knot nematode IDL is discussed.

Tucker ML; Yang R

2013-06-01

243

Variabilidade fisiológica em populações de Meloidogyne paranaensis Physiological variability of two populations of Meloidogyne paranaensis  

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Full Text Available Comparou-se a capacidade reprodutiva de duas populações de Meloidogyne paranaensis, originárias de plantas de soja (Mp-s) e de cafeeiro (Mp-c), em diferentes hospedeiros. A população Mp-s apresentou maior capacidade reprodutiva que a Mp-c, apresentando fator de reprodução superior em tomateiro e em duas cultivares de soja, porém em cafeeiro a Mp-c reproduziu melhor. Em tomateiro 'Santa Clara', ambas reproduziram significativamente mais que nos outros hospedeiros e não houve diferença entre as cultivares de soja 'MS/BR 34' e 'Fepagro RS 10'. Contudo, maior número de populações deverá ser estudado.Two populations of Meloidogyne paranaensis, one from soybean plants (Mp-s) and another from coffee plants (Mp-c) were studied to compare their ability in reproducing on different hosts. Mp-s was able to reproduce more than Mp-c on tomato plants and on two soybean cultivars, but Mp-c showed a higher reproduction factor on coffee plants. On tomato 'Santa Clara', both populations reproduced significantly more than on other hosts, but no difference was detected between the soybean cultivars 'MS/BR 34' and 'Fepagro RS 10'. However, a larger number of populations should be studied.

Alexandre D. Roese; Rosângela D.L. Oliveira; Dagoberto S. Oliveira

2007-01-01

244

The effect of soil water flow and soil properties on the motility of second-stage juveniles of the root-knot nematode (Meloidogyne incognita)  

UK PubMed Central (United Kingdom)

The movement of root-knot nematode Meloidogyne incognita second-stage juveniles was investigated in a column filled with two types of fillings, andisol or sand, under a saturated condition. After incubation with or without soil water flow, the changing distribution of nematodes was monitored. As a result, we observed a tendency for different movement traits of nematodes between andisol and sand. The distance of nematodes movement in sand was always greater than that in andisol in both a percolation test and non-percolation test. In the percolation test, distance of nematodes movement in sand gradually began to increase with increasing time. We attribute this result to a gradual decrease in nematodes activity with time. Nematodes were always affected by the water flow rate, but the distance of nematodes movement did not correspond to water flow volume. We also observed that mobility of nematodes in sand were always greater than that in andisol at both percolation test and non-percolation test. These results are attributed to differences in soil structure and pore distribution of andisol and sand. This study demonstrates a difference in the movement of nematodes influenced by water flow. However, this study also presents evidence that nematodes can resist soil water flow rates that are possible in actual field conditions. Moreover, mobility of nematodes changed considerably with soil structure or pore distribution. All these may contribute to a more stable positioning of nematodes around the rhizosphere of their host plants, and therefore increase the possibility of successful parasitization.

Fujimoto Taketo; Hasegawa Shuichi; Otobe Kazunori; Mizukubo Takayuki

2010-07-01

245

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

Science.gov (United States)

Plant-parasitic nematodes are a major pest of many plant species and cause global economic loss. A phytocystatin gene, Colocasia esculenta cysteine proteinase inhibitor (CeCPI), isolated from a local taro Kaosiang No. 1, and driven by a CaMV35S promoter was delivered into CLN2468D, a heat-tolerant cultivar of tomato (Solanum lycopersicum). When infected with Meloidogyne incognita, one of root-knot nematode (RKN) species, transgenic T1 lines overexpressing CeCPI suppressed gall formation as evidenced by a pronounced reduction in gall numbers. In comparison with wild-type plants, a much lower proportion of female nematodes without growth retardation was observed in transgenic plants. A decrease of RKN egg mass in transgenic plants indicated seriously impaired fecundity. Overexpression of CeCPI in transgenic tomato has inhibitory functions not only in the early RKN infection stage but also in the production of offspring, which may result from intervention in sex determination. PMID:20054551

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

2010-03-01

246

Nematicidal activity of leaf extracts from Lantana camara L. against Meloidogyne incognita (kofoid and white) chitwood and its use to manage roots infection of Solanum melongena L.  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Various concentrations of aqueous leaf extract of Lantana camara were assessed in vitro conditions against second stage juveniles (J2) of Meloidogyne incognita. The standard concentration 'S' of leaf extract was found to be highly nematostatic, where nematodes were completely paralyzed after 12 h and after 48 h of exposure, 96% of juveniles were killed at same concentration. However, the mortality of juveniles was 75% in S/2 dilution at 48 h. The degree of effectiveness a (more) nd dilutions of extract were directly proportional. The percentage of paralyzed juveniles was decreased, when J2 transferred in distilled water after 48 h incubation in standard aqueous leaf extract. Addition of freeze-dried aqueous extract to sterile sandy substrate at S/2 dilution significantly decreased the root-knot infection to susceptible eggplants whereas second stage juveniles (J2) that penetrated roots of eggplant were able to complete development in sterile sandy substrate without treatment of freeze-dried aqueous extract.

Ahmad, Faheem; Rather, Mohmad Azhar; Siddiqui, Mansoor Ahmad

2010-06-01

247

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

UK PubMed Central (United Kingdom)

Proteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyne incognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the large FMRF-amide like peptide (FLP) family in nematodes. Overall protease activity in P. redivivus was four- to fivefold greater than in either of the parasites, a result that might reflect developmental differences. Digestion of the M. incognita FLP KHEFVRFa (substrate Abz-KHEFVRF-Y(3-NO2)a) by M. incognita extract was sevenfold greater than with H. glycines extract and twofold greater than P. redivivus, suggesting species-specific preferences. Additional species differences were revealed upon screening 12 different protease inhibitors. Two substrates were used in the screen, Abz-KHEFVRF-Y(3-NO2)a and Abz-KPSFVRF-Y(3-NO2)a), which was digested equally by all three species. The effects of various inhibitor, substrate and extract source combinations on substrate digestion suggest that M. incognita differs significantly from P. redivivus and H. glycines in its complement of cysteine proteases, particularly cathepsin L-type protease.

Masler EP

2012-03-01

248

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

Science.gov (United States)

Proteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyne incognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the large FMRF-amide like peptide (FLP) family in nematodes. Overall protease activity in P. redivivus was four- to fivefold greater than in either of the parasites, a result that might reflect developmental differences. Digestion of the M. incognita FLP KHEFVRFa (substrate Abz-KHEFVRF-Y(3-NO2)a) by M. incognita extract was sevenfold greater than with H. glycines extract and twofold greater than P. redivivus, suggesting species-specific preferences. Additional species differences were revealed upon screening 12 different protease inhibitors. Two substrates were used in the screen, Abz-KHEFVRF-Y(3-NO2)a and Abz-KPSFVRF-Y(3-NO2)a), which was digested equally by all three species. The effects of various inhibitor, substrate and extract source combinations on substrate digestion suggest that M. incognita differs significantly from P. redivivus and H. glycines in its complement of cysteine proteases, particularly cathepsin L-type protease. PMID:21392420

Masler, E P

2011-03-11

249

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  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 me (more) io 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. Abstract in english 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 (more) ". 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.

Rocha, Fernando da Silva; Campos, Vicente Paulo; Canuto, Renata da Silva; Souza, Ricardo Magela de

2009-02-01

250

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  

Directory of Open Access Journals (Sweden)

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.

Fernando da Silva Rocha; Vicente Paulo Campos; Renata da Silva Canuto; Ricardo Magela de Souza

2009-01-01

251

In vitro and foliar spray evaluation of Verbena officinalis (L.), Erythrina mulungu (Mart. ex Benth.), Quassia amara (L.), Bidens pilosa (L.) and Plantago lanceolata (L.), extracts on Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 Evaluación in vitro y aplicación foliar de Verbena officinalis (L.), Erythrina mulungu (Mart. ex Benth.), Quassia amara (L.), Bidens pilosa (L.) y Plantago lanceolata (L.), sobre Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949  

Directory of Open Access Journals (Sweden)

Full Text Available This study aimed to evaluate the efficiency of aqueous extracts of five species of medicinal plant, Verbena officinalis (L.), Erythrina mulungu (Mart. ex Benth.), Quassia amara (L.), Bidens pilosa (L.) and Plantago lanceolata (L.) in vitro, and sprayed on tomato plants for the control of Meloidogyne incognita. In vitro experiments were conducted in growth chambers in acrylic ELISA plates. The treatments were doses of 0, 10, 20, 30, 40 and 50 g • L-1 of different aqueous extracts. On the sixteenth day the number of second stage juveniles (J2) hatched per treatment was evaluated. The results showed that aqueous extracts of V. officinalis, E. mulungu, Q. amara, B. pilosa and P. lanceolata, reduced the hatching of M. incognita, with the aqueous extract of P. lanceolata showing up to 100% reduction in hatching. The in vivo assay was conducted in a greenhouse. For this, four sprays of different extracts were applied to tomato shoots. According to the results of this test, none of the extracts were efficient at controlling M. incognita through foliar spraying. The efficiency of these extracts to control plant parasitic nematodes during in vivo tests should not be disregarded, however, further studies should be conducted to test different methods of application, doses or methods of extracting the active principles.El objetivo del estudio fue evaluar la eficacia de los extractos acuosos de cinco especies de plantas medicinales, Verbena officinalis (L.), Erythrina mulungu (Mart. ex Benth.), Quassia amara (L.), Bidens pilosa (L.) y Plantago lanceolata (L.) in vitro, y se pulverizaron en las plantas de tomates para el control de Meloidogyne incognita. Los experimentos in vitro fueron realizados en cámaras de crecimiento en placas de ELISA de tipo acrílico. Los tratamientos fueron dosis de 0,10, 20, 30, 40 y 50 g • L-1 de diferentes extractos acuosos. En el día dieciséis se evaluó el número de juveniles segunda etapa (J2)nacidos por tratamiento. Los resultados mostraron que los extractos acuosos de V. officinalis, E. mulungu, Q. amara, B. pilosa y P. lanceolata reducen la eclosión de los juveniles de M. incognita, y el extracto acuoso de P. lanceolata mostró hasta 100% de reducción de la tasa de eclosión. El ensayo in vivo se realizó en un invernadero, y para ello, había cuatro pulverizaciones de diferentes extractos en los brotes de tomate. Según los resultados de esta prueba, ninguno de los extractos por pulverización foliar era eficaz en el control de M. incognita. Sin embargo, no se debe descartar la eficiencia de estos extractos en el control de nematodos parásitos de plantas, pero más estudios se llevan a cabo utilizando diferentes métodos de aplicación, las dosis o métodos de extracción de los principios activos de los extractos.

Milena A Ferrari Mateus; Cacilda M Duarte Rios Faria¹; Renato V Botelho; Rosangela Dallemole-Giaretta; Silvana G Martins Ferreira; Welton L Zaluski

2013-01-01

252

Integrated Management of Meloidogyne incognita Infecting Eggplant by Certain Organic Amendments, Bacillus thuringiensis and Oxamyl with Reference to N P K and Total Chlorophyll Status  

Directory of Open Access Journals (Sweden)

Full Text Available Greenhouse experiment on the impact of horse manure or sesame-oil-cake or Bacillus thuringiensis singly and/or integrated with oxamyl on Meloidogyne incognita infecting eggplant cv. Black long at 25±5°C, revealed that all tested treatments obviously improved plant growth response and reduced nematode development. Among the tested components, B. thuringiensis applied alone or mixed with oxamyl gave the highest percentage of increase in plant growth parameters i.e., plant fresh weight and shoot dry weight with values of 105.9 and 85.8% and 127.8 and 107.5%, respectively, as well as the lowest percent reduction of nematode developmental criteria. Moreover, in concomitant application of horse manure plus oxamyl appeared to be the best treatment in suppressing nematode development and improving plant growth parameters, followed by sesame oil-cake plus oxamyl, then sesame oil-cake and horse manure alone. Meanwhile, length of shoot and number of leaves were positively affected by the tested materials either when applied singly or integrated with oxamyl as compared to nematode alone. Regarding N, P and K status in shoots of eggplant, their concentrations were remarkably reduced by nematode infection. Moreover, single application of any organic amendment or bacterium or oxamyl achieved the highest concentration of N, P and K, whereas the concomitant application of horse manure plus oxamyl showed the highest concentration of phosphorus with value of 0.56 ppm. In addition, the previous treatments obviously decreased the total chlorophyll content of eggplant shoot, whereas nematode infection alone recorded the highest increase percentage for this plant parameter with value of 51.3%.

A.G. El-Sherif; A.R. Refaei; M.E. El-Nagar; Hagar M.M. Salem

2007-01-01

253

Interaction of concurrent populations of Meloidogyne partityla and Mesocriconema xenoplax on pecan  

Science.gov (United States)

The interaction between Meloidogyne partityla and Mesocriconema xenoplax on nematode reproduction and growth of 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...

254

Biological Relationship of Meloidogyne hapla Populations to Alfalfa Cultivars.  

Science.gov (United States)

Greenhouse and growth chamber studies were established to determine if there are pathological and physiological differences among Meloidogyne hapla populations from California (CA), Nevada (NV), Utah (UT), and Wyoming (WY) on alfalfa cultivars classified as resistant or susceptible to root-knot nematodes. In the greenhouse, plant survival was not consistent with resistance classifications. While all highly resistant Nevada Synthetic germplasm (Nev Syn XX) plants survived inoculation with all nematode populations, two cultivars classified as moderately resistant ('Chief' and 'Kingstar') survived (P populations better than did 'Lobo' cultivar, which is classified as resistant. Plant growth of Nev Syn XX was suppressed by only the CA population, whereas growth of the other alfalfa cultivars classified as M. hapla resistant or moderately resistant was suppressed by all nematode populations. Excluding Nev Syn XX, all alfalfa cultivars were severely galled and susceptible to all nematode populations. Except for Nev Syn XX, reproduction did not differ among the nematode populations on alfalfa cultivars. Nev Syn XX was not as favorable a host to CA as were the other cultivars; but, it was a good host (reproductive factor [Rf] = 37). Temperature affected plant resistance; the UT and WY populations were more pathogenic at 15-25 C, and CA was more pathogenic at 30 C. Nev Syn XX was susceptible to all nematode populations, except for CA, at only 30 C, and all other alfalfa cultivars were susceptible to all nematode populations at all temperatures. PMID:19277299

Griffin, G D; Gray, F A

1995-09-01

255

Pathogenicity of Two Populations of Meloidogyne hapla Chitwood on Alfalfaand Sainfoin  

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The pathogenicity of two populations of the northern root-knot nematode, Meloidogyne hapla Chitwood, population 1 (P1) from alfalfa and population 2 (P2) from sainfoin, was studied on both alfalfa and sainfoin for 25 weeks. Alfalfa and sainfoin plants inoculated with P2 had significantly (P ? 0.05) ...

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

256

Differential Sensitivity of Meloidogyne spp. and Heterodera glycines to Selected Nematicides.  

UK PubMed Central (United Kingdom)

Differential sensitivity of Meloidogyne arenaria, M. hapla, M. incognita, M. javanica, and Heterodera glycines races 1 and 5 to the nonfumigant nematicides aldicarb, ethoprop, and fenamiphos was evaluated using a 48-hour root-penetration bioassay. Generally, H. glycines was more tolerant of the nematicides, especially ethoprop, than were the Meloidogyne species. Among Meloidogyne species, M. incognita was most sensitive to aldicarb and fenamiphos, but its reaction to ethoprop was similar to the other three Meloidogyne species.

Gourd TR; Schmitt DP; Barker KR

1993-12-01

257

Efecto de la biodesinfección con residuos de nim (Azadirachta indica A. Juss) sobre población de Meloidogyne spp. en suelo/ Effect of neem (Azadirachta indica A. Juss) Waste on Meloidogyne spp. population in soil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se evaluó el efecto de residuos del proceso industrial de obtención de plaguicidas del nim (Azadirachta indica A. Juss), provenientes de la Fábrica «Rosa E. Simeón», Güines (Mayabeque, Cuba) sobre una población de Meloidogyne spp. El experimento se desarrolló en condiciones semicontroladas, utilizando suelo no estéril, con nivel inicial de Meloidognye spp. de 0,5 juveniles de segundo estadio (J2)-huevos.g de suelo-1. Se establecieron ocho tratamientos, cuatro de (more) los cuales se inocularon adicionalmente con 5 J2-huevos.g de suelo-1 de Meloidogyne incognita (Kofoid y White) Chitwood y se empleó como hospedante tomate (Solanum lycopersicom L. var. Campbell 28). Se aplicaron tres dosis de residuos 138,47 g.maceta-1, 60,28 g.maceta-1 y 40,19 g.maceta-1 (lo que equivale a aplicar 4, 3 y 2 kg.m2-1 respectivamente). A los 50 días se determinó el Índice de Agallamiento (IA) (0 a 5 grados), longitud del tallo y masa fresca de raíces. Las mayores poblaciones de nematodos se produjeron en el tratamiento testigo (sin nim) (IA =5), exhibiendo diferencias significativas con aquellos donde se aplicaron los residuos, destacándose el tratamiento con 138,47 g.maceta-1 (equivalente a 4 kg.m2-1) que mostró un IA de 2,4. Los resultados mostraron la potencialidad que posee este desecho para el manejo de nematodos y la necesidad de estudiar su efecto sobre las plantas y las propiedades físico, químicas y biota del suelo. Abstract in english The effect of the waste from the industrial production of neem-based pesticides (Azadirachta indica A. Juss) originated in «Rosa Elena Simeón» factory in Güines (Mayabeque, Cuba) on Meloidogyne spp. population was evaluated, The experiment was carried out under semi-controlled conditions, using non sterilized soil with an initial level of Meloidogyne spp. of 0,5 juveniles-eggs.g of soil-1. Eight treatments were set up; four of them were additionally inoculated with 5 (more) juveniles-eggs.g of soil-1 of Meloidogyen incognita (Kofoid and White) Chitwood. Tomato (Solanum lycopersicom L. var. Campbell 28) was used as host. Three doses of the waste (138,47g.pot-1, 60,288 g.pot-1 and 40,19 g.pot¹; -equivalent to 4, 3 and 2 kg.m2-1 respectively) were applied. After fifty days, root knot galling index (GI) (0 to 5 grades), stem length and fresh weight of roots were evaluated. The highest populations appeared in the control treatment (without neem) (GI=5), which differed significantly from the treatments with the waste, where the best behavior was observed with 138,47 g.pot-1 (equivalent to 4 kg.m2-1) with a GI of 2,4. The results showed the potential of this waste for the management of plant parasitic nematodes and the need for studies on the effect upon the plants and the physical-chemical properties and biota of soils.

Rodríguez, Mayra G; Gómez, Lucila; Hernández-Ochandía, Dainé; Enrique, R; Miranda, Ileana; Pino, Oriela; Castro-Lizazo, I; Rosales, L. Carolina; Díaz-Viruliche, Luisa

2012-12-01

258

Desempenho de genótipos de algodoeiro na presença ou não de rotação de cultura com Crotalaria spectabilis, em área infestada com Meloidogyne incognita/ Performance of cotton genotypes in the presence or absence of crop rotation with Crotalaria spectabilis in an area infested with Meloidogyne incognita  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Em área naturalmente infestada com Meloidogyneincognita raça 3, localizada em Primavera do Leste-MT, foi estudado o desempenho de 21 genótipos de algodoeiro com níveis diversos de tolerância ao nematoide, com a adoção ou não de rotação de cultura com Crotalaria spectabilis. De modo geral a rotação diminuiu a severidade dos sintomas exibidos pelas plantas, devidos ao ataque do parasita, e promoveu aumento na produtividade de algodão. Entretanto, seu efeito nã (more) o foi suficiente para tornar eficaz o desempenho de genótipos de baixa tolerância ao nematoide, os quais, mesmo na presença da leguminosa, tiveram notas para sintomas 142% maiores e produtividades de algodão 57% menores do que as cultivares mais tolerantes. Alta correlação entre as médias de produção dos genótipos na seqüência ou não da leguminosa e ausência de interação genótipo x rotação, indicaram que, embora em patamar mais elevado de produção, a tendência de desempenho dos genótipos foi a mesma na presença e na ausência da crotalária. De tal modo que, na média, a produção dos três genótipos mais tolerantes, na ausência de rotação, foi, ainda assim, 48% superior à dos genótipos mais intolerantes, na presença da crotalária. As perdas mínimas possíveis na produção, atribuíveis ao uso de genótipos intolerantes, foram estimadas em 37% na ausência da rotação e em 29% com rotação. Abstract in english In an area naturally infested with Meloidogyne incognita race 3, located in Primavera do Leste, Mato Grosso State, Brazil, the performance of 21 cotton genotypes having different levels of tolerance to this parasitic nematode was studied, in the presence or absence of crop rotation with Crotalaria spectabilis. A general trend was observed for crop rotation to reduce the severity of symptoms exibited by plant sowing to nematode incidence, and lead to increased cotton yield (more) . However, its effect was not sufficient to increase the performance of genotypes with low tolerance to the parasite, which, even under the crop rotation schem, had disease sympton rates that were 142% higher and cotton yields that were 57% lower than those obtained for more tolerant genotypes. High correlation between average yield in the presence or absence of crop rotation, and absence of interaction between genotype and crop rotation, indicated that, although at higher yield level being achieved, the tendency of genotype performance remained the same in both systems. The yield of the three more tolerant genotypes in the absence of crop rotation was 48% superior to that of the three least tolerant genotypes under crop rotation. The minimum possible losses, attributable to the use of susceptible genotypes, were estimated at 37% and 29%, respectively, without crop rotation being used or under conditions of crop rotation.

Galbieri, Rafael; Fuzatto, Milton G.; Cia, Edivaldo; Welter, Adinara M.; Fanan, Sheila

2011-10-01

259

Relative DNA Content and Chromosomal Relationships of some Meloidogyne, Heterodera, and Meloidodera spp. (Nematoda: Heteroderidae).  

Science.gov (United States)

The relative DNA content of hypodermal nuclei of preparasitic, 2nd-stage larvae was determined cytophotometrically in 19 populations belonging to 13 species of Meloidogyne, Heterodera and Meloidodera. In Meloidogyne hapla, M. arenaria, M. incognita and M. javanica, total DNA content per nucleus is proportional to their chromosome number, indicating that chromosomal forms with high chromosome numbers are truly polyploid. M. graminicola, M. grarninis and M. ottersoni have a DNA content per chromosome significantly lower than that of the other Meloidogyne species. Within Heterodera, species with high chromosome numbers have proportionally higher DNA content, indicating again polyploidy. DNA content per chromosome in Meloidogyne is one third that of Heterodera and one haft that of Meloidodera floridensis. The karyotypic relationships of the three genera are still not clearly understood. PMID:19319282

Lapp, N A; Triantaphyllou, A C

1972-10-01

260

Relative DNA Content and Chromosomal Relationships of some Meloidogyne, Heterodera, and Meloidodera spp. (Nematoda: Heteroderidae).  

UK PubMed Central (United Kingdom)

The relative DNA content of hypodermal nuclei of preparasitic, 2nd-stage larvae was determined cytophotometrically in 19 populations belonging to 13 species of Meloidogyne, Heterodera and Meloidodera. In Meloidogyne hapla, M. arenaria, M. incognita and M. javanica, total DNA content per nucleus is proportional to their chromosome number, indicating that chromosomal forms with high chromosome numbers are truly polyploid. M. graminicola, M. grarninis and M. ottersoni have a DNA content per chromosome significantly lower than that of the other Meloidogyne species. Within Heterodera, species with high chromosome numbers have proportionally higher DNA content, indicating again polyploidy. DNA content per chromosome in Meloidogyne is one third that of Heterodera and one haft that of Meloidodera floridensis. The karyotypic relationships of the three genera are still not clearly understood.

Lapp NA; Triantaphyllou AC

1972-10-01

 
 
 
 
261

Effects of Cropping Sequences on Population Densities of Meloidogyne haplaand Carrot Yield in Organic Soil  

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The influence of various cropping sequences on population densities of Meloidogyne hapla and carrot yield was studied in organic soil under microplot-and field conditions. Spinach, radish, barley, oat, and wheat were poor or nonhosts for M. hapla. Population densities of M. hapla were maintained or ...

Bélair, Guy

262

Morphological and Molecular Evaluation of a Meloidogyne hapla Population Damaging Coffee (Coffea arabica) in Maui, Hawaii  

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An unusual population of Meloidogyne hapla, earlier thought to be an undescribed species, was found causing large galls, without adventitious roots, and substantial damage to coffee in Maui, Hawaii. Only in Brazil had similar damage to coffee been reported by this species. Unlike M. exigua from Sout...

Handoo, Z. A.; Skantar, A. M.; Carta, L. K.; Schmitt, D. P.

263

Seasonal Populations of Pratylenchus penetrans and Meloidogyne hapla in Strawberry Roots  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Strawberry roots were sampled through the year to determine the populations and distribution of Pratylenchus penetrans and Meloidogyne hapla. Three strawberry root types were sampled—structural roots; feeder roots without secondary tissues; and suberized, black perennial roots. Both lesion and root-...

Lamindia, J. A.

264

Influence of Alfalfa Plant Growth on the Multiplication Rates and CeilingPopulation Density of Meloidogyne hapla  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The rates of reproduction and multiplication of Meloidogyne hapla decreased as a result of self-regulatory, density-dependent processes with time and nematode population increase in the soil and roots of Medicago sativa cv. Cuf 101. Juvenile, egg, and mature female population densities increased at ...

Noling, J. W.; Ferris, H.

265

Development of Four Populations ofMeloidogyne hapla on Two Cultivars, ofCucumber at Different Temperatures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

266

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

UK PubMed Central (United Kingdom)

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 population produced no egg masses on cucumber, but a population from Britain and one from America with 17 chromosomes produced more egg masses at this temperature than at 20 or 24 C. Dissection of the galls showed that on cucumber many larvae died or their growth and development was slowed.

Stephan ZA; Trudgill DL

1982-10-01

267

Inter- and intra-specific cuticle variation between amphimictic and parthenogenetic species of root-knot nematode (Meloidogyne spp.) as revealed by a bacterial parasite (Pasteuria penetrans).  

Science.gov (United States)

Specific host-parasite interactions exist between species and strains of plant parasitic root-knot nematodes and the Gram-positive bacterial hyperparasite Pasteuria penetrans. This bacterium produces endospores that adhere to the cuticle of migrating juveniles, germinate and colonise the developing female within roots. Endospore attachment of P. penetrans populations to second-stage juveniles of the root-knot nematode species Meloidogyne incognita and Meloidogyne hapla showed there were interactive differences between bacterial populations and nematode species. Infected females of M. incognita produced a few progeny which were used to establish two nematode lines from single infective juveniles encumbered with either three or 26 endospores. Single juvenile descent lines of each nematode species were produced to test whether cuticle variation was greater within M. hapla lines that reproduce by facultative meiotic parthenogenesis than within lines of M. incognita, which reproduces by obligate parthenogenesis. Assays revealed variability between broods of individual females derived from single second-stage juvenile descent lines of both M. incognita and M. hapla suggesting that progeny derived from a single individual can differ in spore adhesion in both sexual and asexual nematode species. These results suggest that special mechanisms that produced these functional differences in the cuticle surface may have evolved in both sexually and asexually reproducing nematodes as a strategy to circumvent infection by this specialised hyperparasite. PMID:18171577

Davies, K G; Rowe, J A; Williamson, V M

2007-12-03

268

Seasonal Populations of Pratylenchus penetrans and Meloidogyne hapla in Strawberry Roots.  

Science.gov (United States)

Strawberry roots were sampled through the year to determine the populations and distribution of Pratylenchus penetrans and Meloidogyne hapla. Three strawberry root types were sampled-structural roots; feeder roots without secondary tissues; and suberized, black perennial roots. Both lesion and root-knot nematodes primarily infected feeder roots from structural roots or healthy perennial roots. Few nematodes were recovered from soil, diseased roots, or suberized roots. Lesion nematode recovery was correlated with healthy roots. In both 1997 and 1998, P. penetrans populations peaked about day 150 (end of May) and then declined. The decline in numbers corresponded to changes in total strawberry root weight and root type distribution. The loss of nematode habitat resulted from loss of roots due to disease and the transition from structural to suberized perennial roots. Meloidogyne hapla juvenile recovery peaked around 170 days (mid June) in 1997 and at 85, 147, 229, and 308 days (late March, late May, mid August, and early November, respectively) in 1998. There appear to be at least four generations per year of M. hapla in Connecticut. Diagnostic samples from an established strawberry bed may be most reliable and useful when they include feeder roots taken in late May. PMID:19265965

Lamindia, J A

2002-12-01

269

Seasonal Populations of Pratylenchus penetrans and Meloidogyne hapla in Strawberry Roots.  

UK PubMed Central (United Kingdom)

Strawberry roots were sampled through the year to determine the populations and distribution of Pratylenchus penetrans and Meloidogyne hapla. Three strawberry root types were sampled-structural roots; feeder roots without secondary tissues; and suberized, black perennial roots. Both lesion and root-knot nematodes primarily infected feeder roots from structural roots or healthy perennial roots. Few nematodes were recovered from soil, diseased roots, or suberized roots. Lesion nematode recovery was correlated with healthy roots. In both 1997 and 1998, P. penetrans populations peaked about day 150 (end of May) and then declined. The decline in numbers corresponded to changes in total strawberry root weight and root type distribution. The loss of nematode habitat resulted from loss of roots due to disease and the transition from structural to suberized perennial roots. Meloidogyne hapla juvenile recovery peaked around 170 days (mid June) in 1997 and at 85, 147, 229, and 308 days (late March, late May, mid August, and early November, respectively) in 1998. There appear to be at least four generations per year of M. hapla in Connecticut. Diagnostic samples from an established strawberry bed may be most reliable and useful when they include feeder roots taken in late May.

Lamindia JA

2002-12-01

270

Characterization of a Root-Knot Nematode Population of Meloidogyne arenaria from Tupungato (Mendoza, Argentina).  

Science.gov (United States)

Root-knot nematodes (Meloidogyne spp.) are polyphagous plant parasites of global importance. Successful host infection depends on the particular interaction between a specific nematode species and race and a specific plant species and cultivar. Accurate diagnosis of nematode species is relevant to effective agricultural management; and benefits further from understanding the variability within a single nematode species. Here, we described a population of M. arenaria race 2 from Mendoza (Argentina). This study represents the first morphometric, morphological, biochemical, reproductive, molecular, and host range characterization of a root-knot nematode species from Argentina. Even after gathering morphological and morphometric data of this population and partially sequencing its rRNA, an unequivocal taxonomic assignment could not be achieved. The most decisive data was provided by esterase phenotyping and molecular methods using SCARs. These results highlight the importance of taking a multidimensional approach for Meloidogyne spp. diagnosis. This study contributes to the understanding of the variability of morphological, reproductive and molecular traits of M. arenaria, and provides data on the identification of root-knot nematodes on tomato cultivars from Argentina. PMID:23481918

Evangelina García, Laura; Sánchez-Puerta, María Virginia

2012-09-01

271

Characterization of a Root-Knot Nematode Population of Meloidogyne arenaria from Tupungato (Mendoza, Argentina).  

UK PubMed Central (United Kingdom)

Root-knot nematodes (Meloidogyne spp.) are polyphagous plant parasites of global importance. Successful host infection depends on the particular interaction between a specific nematode species and race and a specific plant species and cultivar. Accurate diagnosis of nematode species is relevant to effective agricultural management; and benefits further from understanding the variability within a single nematode species. Here, we described a population of M. arenaria race 2 from Mendoza (Argentina). This study represents the first morphometric, morphological, biochemical, reproductive, molecular, and host range characterization of a root-knot nematode species from Argentina. Even after gathering morphological and morphometric data of this population and partially sequencing its rRNA, an unequivocal taxonomic assignment could not be achieved. The most decisive data was provided by esterase phenotyping and molecular methods using SCARs. These results highlight the importance of taking a multidimensional approach for Meloidogyne spp. diagnosis. This study contributes to the understanding of the variability of morphological, reproductive and molecular traits of M. arenaria, and provides data on the identification of root-knot nematodes on tomato cultivars from Argentina.

Evangelina García L; Sánchez-Puerta MV

2012-09-01

272

Influence of Alfalfa Plant Growth on the Multiplication Rates and Ceiling Population Density of Meloidogyne hapla.  

UK PubMed Central (United Kingdom)

The rates of reproduction and multiplication of Meloidogyne hapla decreased as a result of self-regulatory, density-dependent processes with time and nematode population increase in the soil and roots of Medicago sativa cv. Cuf 101. Juvenile, egg, and mature female population densities increased at a maximum rate until damage to the host resulted in alfalfa yield reductions. Temporal differences in multiplication and reproduction rates of M. hapla were observed to be a function of initial population density (Pi), host damage, and root biomass, indicating increased levels of competition for a constant but limited number of feeding sites. Over time, a log linear relationship emerged between multiplication rate of M. hapla and Pi. Slopes of -0.90953 for combined eggs and juveniles and -0.71349 for mature females indicated a gradual approach to ceiling densities. Reproductive rates decreased exponentially from an initial maximal value of 200 to a relatively constant rate of 53 eggs per female.

Noling JW; Ferris H

1986-10-01

273

MORPHOLOGICAL AND MOLECULAR EVALUATION OF A MELOIDOGYNE HAPLA POPULATION DAMAGING COFFEE (COFFEA ARABICA L.) IN MAUI, HAWAII  

Science.gov (United States)

An unusual male /female population of Meloidogyne hapla, earlier thought to represent an undescribed species, was found to cause large galls without proliferating rootlets and significant damage to coffee on Maui in the Hawaiian islands for the first time in the Pacific region. Similar galls and dam...

274

Relationship Between Crop Losses and Initial Population Densities of Meloidogyne arenaria in Winter-Grown Oriental Melon in Korea  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To determine the economic threshold level, oriental melon (Cucumis melo L. cv. Geumssaragi-euncheon) grafted on Shintozoa (Cucurbita maxima × Cu. moschata) was planted in plots (2 × 3 m) under a plastic film in February with a range of initial population densities (Pi) of Meloidogyne arenaria. The r...

Kim, D.G.; Ferris, H.

275

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

Science.gov (United States)

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 the presence of M. partityla alone or in combination with M. xenoplax as compared with the uninoculated control trees. The interaction between M. partityla and M. xenoplax was significant for dry root weight 37 months after inoculation. Results indicate that the presence of the two nematode species together caused a greater reduction in root growth than M. xenoplax alone, but not when compared to M. partityla alone. Mouse-ear symptom severity in pecan leaves was increased in the presence of M. partityla compared with M. xenoplax and the uninoculated control. Infection with M. partityla increased severity of mouse-ear symptoms expressed by foliage. The greater negative impact of M. partityla on vegetative growth of pecan seedlings in field microplots indicates that it is likely a more detrimental pathogen to pecan than is M. xenoplax and is likely an economic pest of pecan. PMID:19440263

Nyczepir, A P; Wood, B W

2008-09-01

276

Resistance to Meloidogyne spp. in Allohexaploid Wheat Derived from Triticum turgidum and Aegilops squarrosa  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Expression of resistance to Meloidogyne incognita and M. javanica from Aegilops squarrosa was studied in a synthetic allohexaploid produced from Triticum turgidum var. durum cv. Produra and Ae. squarrosa G 3489. The reproductive rate of different races of M. incognita and M. javanica, expressed in e...

Kaloshian, I.; Roberts, P. A.; Thomason, I. J.

277

Effects of Meloidogyne spp. and Rhizoctonia solani on the Growth of Grapevine Rootings  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A disease complex involving Meloidogyne incognita and Rhizoctonia solani was associated with stunting of grapevines in a field nursery. Nematode reproduction was occurring on both susceptible and resistant cultivars, and pot experiments were conducted to determine the virulence of this M. incognita ...

Walker, G. E.

278

Induced Resistance to Meloidogyne hapla by other Meloidogyne species onTomato and Pyrethrum Plants  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Advance inoculation of the tomato cv. Celebrity or the pyrethrum clone 223 with host-incompatible Meloidogyne incognita or M. javanica elicited induced resistance to host-compatible M. hapla in pot and field experiments. Induced resistance increased with the length of the time between inoculations a...

Ogallo, J. L.; McClure, M. A.

279

Pathogencity and reproductive potential of Meloidogyne mayaguensis and M. floridensis compared with three common Meloidogyne spp.  

Science.gov (United States)

The pathogenicity and reproductive potential of Meloidogyne mayaguensis and M. floridensis, two new species reported in Florida agriculture, were compared to those of M. arenaria race 1, M. incognita race 4, and M. javanica race 1 on tomato (Lycopersicon esculentum Mill.) in field microplots. Two tr...

280

Influence of Meloidogyne hapla on Alfalfa Yield and Host Population Dynamics.  

UK PubMed Central (United Kingdom)

Self-thinning in alfalfa, a dynamic process involving the progressive elimination of the weakest plants, was enhanced by Meloidogyne hapla. Alfalfa stand densities decreased exponentially with time and were reduced 62% (P = 0.05) in the presence of M. hapla. As stand densities decreased over time, mean plant weights increased at a rate 2.59 times faster in the absence of M. hapla. In a stepwise multiple regression analysis, 65% of the total variation in yield could be explained by changes in stand density and 85% by average weight of individual stems. Alfalfa yields were suppressed (P = 0.05) by M. hapla, with suppression generally increasing with time and as the nematode population density increased. Yield suppression was attributable primarily to the decline in plant numbers and to suppression in individual plant weights.

Noling JW; Ferris H

1985-10-01

 
 
 
 
281

Differential Reaction of Alfalfa Cultivars to Meloidogyne hapla and M. chitwoodi Populations.  

UK PubMed Central (United Kingdom)

Meloidogyne hapla reproduced and suppressed growth (P < 0.05) of susceptible Lahontan and Moapa alfalfa at 15, 20, and 25 C. At 30 C, resistant Nevada Syn XX lost resistance to M. hapla. M. hapla invaded and reproduced on Rhizobium meliloti nodules of Lahontan and Moapa, inducing giant cell formation and structural disorder of vascular bundles of nodules without disrupting bacteroids. At 15, 20, and 25 C a M. chitwoodi population from Utah reproduced on Lahontan, Moapa, and Nevada Syn XX alfalfa, suppressing growth (P < 0.05). Final densities of the Utah M. chitwoodi population were greater (P < 0.05) than those of Idaho and Washington State populations on Lahontan at 15 and 25 C and on Nevada Syn XX at 15 C, but were less consistent and smaller (P < 0.05) than those of M. hapla on Lahontan and Moapa at 20 and 25 C. Inconsistent reproduction of the Utah M. chitwoodi population on alfalfa suggests the possible existence of nematode strains revealed by variability in alfalfa resistance. No reproduction or inconsistent final nematode population densities with no damage were observed on Lahontan, Moapa, and Nevada Syn XX plants grown in soil infested with Idaho and Washington State M. chitwoodi populations.

Griffin GD; Inserra RN; Vovlas N; Sisson DV

1986-07-01

282

Hermaphroditism in Meloidogyne hapla  

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Hermaphrodites were detected in diploid and polyploid isolates of population 86-Va of Meloidogyne hapla. Young hermaphrodites are indistinguishable from normal females. Initially, hermaphrodite ovaries are filled with oocytes at various stages of development. Hermaphroditism is expressed later when ...

Triantaphyllou, A. C.

283

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 (more) 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. Abstract in english 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'). T (more) wo 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.

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

2010-03-01

284

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

Directory of Open Access Journals (Sweden)

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.

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

2010-01-01

285

Effects of Cropping Sequences on Population Densities of Meloidogyne hapla and Carrot Yield in Organic Soil.  

Science.gov (United States)

The influence of various cropping sequences on population densities of Meloidogyne hapla and carrot yield was studied in organic soil under microplot-and field conditions. Spinach, radish, barley, oat, and wheat were poor or nonhosts for M. hapla. Population densities of M. hapla were maintained or increased on cabbage, celery, lettuce, leek, marigold, and potato. Marketable percent-age and root weight of carrots were greater following spinach, oat, radish, and fallow-onion than those following two crops of onion or carrot in microplots. Under field conditions, the carrot-onion-oat-carrot cropping sequence decreased M. hapla population densities and provided a 282% increase in marketable yield of carrot compared to a carrot monoculture. Two consecutive years of onion increased M. hapla population densities causing severe root galling and a 50% yield loss in the following crop of carrot. Based on root-gall indices, carrots could be grown economically for 2 years following radish, spinach, and oat, but not following onion and carrot without the use of nematicides. PMID:19283022

Bélair, G

1992-09-01

286

Effects of Cropping Sequences on Population Densities of Meloidogyne hapla and Carrot Yield in Organic Soil.  

UK PubMed Central (United Kingdom)

The influence of various cropping sequences on population densities of Meloidogyne hapla and carrot yield was studied in organic soil under microplot-and field conditions. Spinach, radish, barley, oat, and wheat were poor or nonhosts for M. hapla. Population densities of M. hapla were maintained or increased on cabbage, celery, lettuce, leek, marigold, and potato. Marketable percent-age and root weight of carrots were greater following spinach, oat, radish, and fallow-onion than those following two crops of onion or carrot in microplots. Under field conditions, the carrot-onion-oat-carrot cropping sequence decreased M. hapla population densities and provided a 282% increase in marketable yield of carrot compared to a carrot monoculture. Two consecutive years of onion increased M. hapla population densities causing severe root galling and a 50% yield loss in the following crop of carrot. Based on root-gall indices, carrots could be grown economically for 2 years following radish, spinach, and oat, but not following onion and carrot without the use of nematicides.

Bélair G

1992-09-01

287

Bahiagrass for the Management of Meloidogyne arenaria in Peanut.  

UK PubMed Central (United Kingdom)

Bahiagrass (Paspalum notatum) cultivars Argentine, Pensacola, and Tifton-9 were non-hosts for Meloidogyne arenaria, M. incognita, and Heterodera glycines in a greenhouse experiment using field soil infested with these nematodes. The effect of Pensacola bahiagrass in rotation with peanut (Arachis hypogaea) on M. arenaria was studied in 1986 and 1987 in a field at the Wiregrass substation near Headland, Alabama. Each year soil densities of second-stage juveniles of M. arenaria, determined near peanut harvest, were 96-98% lower under bahiagrass than under peanut. In 1987 peanut yields in plots following bahiagrass were 27% higher than in plots under peanut monoculture. Juvenile population densities in bahiagrass-peanut plots were 41% lower than in plots with continuous peanut. Using bahiagrass for reducing population densities of M. arenaria and increasing peanut yield was as effective as using aldicarb at the recommended rates for peanut.

Rodríguez-Kábana R; Weaver CF; Robertson DG; Ivey H

1988-10-01

288

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

Directory of Open Access Journals (Sweden)

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

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

2012-01-01

289

Scanning electron microscopy of perineal patterns of three species of Meloidogyne.  

UK PubMed Central (United Kingdom)

The perineal pattern of Meloidogyne graminicola is oval, characterized by the anastomosing of cuticular striae converging, and elevating at the tail terminus. A deep lateral incisure forming a low arch traverses the rounded perineal pattern of Meloidogyne hapla. Punctations at the tail region of M. hapla are not observed with the scanning electron microscope. Minute crosslines invaginate with the vulvar lips of Meloidogyne incognita. Punctate indentations around the anal opening and bordering the lateral sides of the vulvar slit of M. incognita are revealed.

Yik CP; Birchfield W

1978-04-01

290

Respostas de genótipos de Coffea spp. a diferentes populações de Meloidogyne exigua Responses of different genotypes of Coffea spp. to Meloidogyne exigua populations  

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Full Text Available Em Meloidogyne exigua, um dos principais patógenos do cafeeiro no Brasil, já foram observadas variabilidade bioquímica, molecular, morfológica e fisiológica. No entanto, a expressão desta variabilidade quanto à virulência a genótipos de cafeeiro não é bem conhecida. O objetivo deste trabalho foi estudar o efeito de populações de M. exigua, as quais exibiam diferentes fenótipos de esterase e preferências por hospedeiros, em 25 genótipos de cafeeiro, com o propósito de se conhecer melhor a interação de biótipos desse nematóide com o gênero Coffea. Seis mudas de cafeeiro por tratamento foram inoculadas no estádio de 3 a 4 pares de folhas definitivas com 5.000 ovos de cada população de M. exigua por planta. O número de galhas e ovos por sistema radicular e a biomassa da matéria fresca das raízes foram avaliados aos 110 dias após a inoculação. Em função da reação frente às populações de M. exigua, os genótipos de Coffea spp. foram classificados em 14 suscetíveis, 5 imunes e 6 segregantes. Estes últimos segregaram de maneira diferenciada conforme a população do patógeno, evidenciando a existência de variabilidade intraespecífica em relação à virulência ao cafeeiro. Assim, o uso de diferentes populações desse patógeno, que englobem essa variabilidade é fundamental no desenvolvimento de cultivares resistentes.In Brazil, Meloidogyne exigua is one of the most important pathogens that attack coffee plants. Morphological, biochemical, molecular and physiological variabilities have been observed in M. exigua, but the expression of these variabilities in coffee genotypes is not well known. To evaluate the effect of M. exigua on 25 Coffea spp. genotypes, populations exhibiting distinct esterase phenotypes and host suitability variations were selected. Thus, coffee seedlings at the stage of 3-4 sets of two leaves were inoculated with 5000 eggs of either population, with each treatment including six replicates. The evaluation occurred 110 days after inoculation, by counting galls and eggs per root system and measuring root fresh weight. According to the genotypes' reaction, three groups of Coffea spp. were detected: fourteen expressed susceptible reaction, six segregated and five were immune to M. exigua populations. The segregating genotypes behaved in a different way in relation to the four populations. Thus, the utilization of different populations showing this variability is fundamental for a breeding program that aims to develop resistant cultivars.

Rodrigo V. Silva; Rosângela D.L. Oliveira; Antonio A. Pereira; Dalila J. Sêni

2007-01-01

291

DNA characterization and relationship of the genomes of some Meloidogyne species  

Energy Technology Data Exchange (ETDEWEB)

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 83.63/sup 0/C. 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 /sup 32/P-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.

Pableo, E.C.

1987-01-01

292

DNA characterization and relationship of the genomes of some Meloidogyne species  

International Nuclear Information System (INIS)

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.

1987-01-01

293

Effects of population densities of Meloidogyne hapla on growth and yield of tomato.  

UK PubMed Central (United Kingdom)

Growth and yield of 'Veebrite' tomato were studied in 20-cm (i.d.) clay-tile microplots containing initially 260, 1,840, 6,120, or 27,950 Meloidogyne hapla larvae/kg of soil. Low nematode numbers stimulated, and the highest nematode population suppressed, vegetative plant growth. More tomatoes, with a higher total weight, were harvested from plants infested with 260 and 1,840 nematode larvae at planting than from those with initial densities of 6,120 and 27,950 larvae. At the two highest densities, the cumulative fruit production (weight) was suppressed by 10% and 40%, respectively. The increase in growth and yield at the lower densities appeared to be due to an increase in the size of the root systent. However, at the higher densities, yield was no longer directly related to root weight. The reproduction factor of M. hapla was negatively correlated with initial density; for the lowest and highest initial densities, it was 96X and 7X at midseason, and 354X and 3X at harvest, respectively. The equilibrium density was 63,000 larvae/kg of soil; initial densities larger than 2,000 larvae/kg of soil may require control.

Olthof TH; Potter JW

1977-10-01

294

Pathogenicity of Meloidogyne spp. (Tylenchida: Meloidogynidae) from Brazil and Central America on two genotypes of Coffea arabica Patogenicidade de Meloidogyne spp. (Tylenchida: Meloidogynidae) originárias do Brasil e América Central a dois genótipos de Coffea arabica  

Directory of Open Access Journals (Sweden)

Full Text Available Among the most damaging root-knot nematode species, Meloidogyne exigua, M. paranaensis, M. incognita, M. arabicida, M. izalcoensis and M. mayaguensis are major agronomic constraints in coffee-growing areas in Brazil and other Latin American countries. The resistance reaction to those six species was studied for the H 419-5-4-5-2 progeny, derived from the artificial hybridization between Catuaí Amarelo 'IAC 30' x Timor Hybrid UFV 445-46 selection. The Catuaí Vermelho IAC 144 genotype was used as susceptibility control for Meloidogyne spp. The genotypes were inoculated with 6,000 eggs/plant and the experiment was set up in a completely randomized design, replicated 10 times for each Meloidogyne species and genotype. The evaluation was performed at 240 days after inoculation and the reproduction factor (RF= Final population/6000) was used as the variable to evaluate resistance. M. exigua caused typical rounded galls mostly on new roots, and egg-masses were produced mostly in the cortex under the root epidermis. M. incognita, M. paranaensis and M. arabicida caused swollen roots, peeling and cracking of cortical root tissue. No symptoms were observed for M. mayaguensis. M. izalcoensis induced very small galls, mostly on the extremity of new roots. Egg-masses were produced outside the roots in large quantities. The genotype IAC 144 was susceptible (FR>1.0) to all Meloidogyne spp. studied, except to M. mayaguensis. The nematode isolate used in this experiment seems to be a weak parasite for coffee. The H 419-5-4-5-2 progeny was resistant to M. exigua (FREntre as espécies de nematóides de galhas mais danosas ao cafeeiro, Meloidogyne exigua, M. paranaensis, M. incognita, M. arabicida, M. izalcoensis e M. mayaguensis são as que causam os maiores problemas em áreas de cultivo de café no Brasil e países da América Latina. A reação de resistência a essas seis espécies foi estudada na progênie H 419-5-4-5-2, obtida do cruzamento artificial entre a cultivar Catuaí Amarelo IAC 30 com a seleção de Híbrido de Timor UFV 445-46. As genótipos foram inoculados com 6.000 ovos/planta e o experimento foi conduzido no delineamento inteiramente ao acaso, com 10 repetições para cada espécie de Meloidogyne e cada genótipo de cafeeiro. A avaliação foi realizada 240 dias após a inoculação. O Fator de Reprodução (FR= População Final/6000) foi usado como variável para se avaliar a resistência. M. exigua causou galhas arredondadas típicas, sobretudo nas raízes novas. M. incognita, M. paranaensis e M. arabicida causaram engrossamento nas raízes, descolamento cortical e rachaduras em várias partes do sistema radicular.Nenhum sintoma foi observado para M. mayaguensis. M. izalcoensis causou galhas pequenas, a maioria na extremidade das raízes novas. As massas de ovos foram produzidas externamente e em grande número. O genótipo IAC 144 (testemunha) foi suscetível (FR>1.0) a todas espécies de Meloidogyne, exceto a M. mayaguensis. Esse isolado mostrou-se um parasita fraco para o cafeeiro. A progênie H 419-5-4-5-2 foi resistente a M. exigua e M. mayaguensis (FR<1) e suscetível a M. incognita, M. paranaensis, M. arabicida e M. izalcoensis.

Regina M.D.G. Carneiro; Luiz F.G. de Mesquita; Wallace Gonçalves; Antônio A. Pereira

2008-01-01

295

Meloidogyne mayaguensis RAMMAH Y HIRSCHMANN, PLAGA EMERGENTE PARA LA AGRICULTURA TROPICAL Y SUBTROPICAL/ Meloidogyne mayaguensis RAMMAH Y HIRSCHMANN, EMERGENT PEST FOR TROPICAL AND SUBTROPICAL AGRICULTURE  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Meloidogyne mayaguensis Rammah y Hirschmann, constituye una importante plaga en países de la zona tropical y subtropical, donde parasita de manera natural más de 30 especies de diferentes plantas de cultivo como guayaba (Psidium guajava), cafeto (Coffea spp.), hortalizas, ornamentales y arvenses. Su distribución ha ocurrido relativamente rápido debido a factores antropogénicos y la mayor preocupación con esta especie es su capacidad para parasitar y reproducirse en (more) plantas con resistencia a Meloidogyne spp. Esta especie presenta alta variabilidad en la morfología de su patrón perineal, por lo que es recomendable, para su identificación, el uso de elementos complementarios como los que ofrecen los perfiles de esterasas. Esta especie puede hallarse en poblaciones concomitantes junto a Meloidogyne incognita, Meloidogyne arenaria y Meloidogyne javanica, haciendo más complejo su diagnóstico y manejo. Entre las regulaciones empleadas para mitigar su efecto negativo se encuentran, la implementación de medidas de cuarentena interna y el uso de Cadusafos y Abamectina, con resultados variables. De igual modo, grupos de investigación en África y América han evaluado extractos de Crotalaria spp. y agentes de control biológico (Arthrobotrys spp.), entre otras tácticas. M. mayaguensis se considera una de las especies más peligrosas del género, su detección, correcta identificación y contención en las áreas donde aparece constituyen uno de los retos más importantes de las autoridades sanitarias en los países donde ha sido encontrada, para los cuales la información oportuna y capacitación efectiva de los actores involucrados en esta esfera representa un elemento de vital importancia para el enfrentamiento a esta plaga emergente. Abstract in english Meloidogyne mayaguensis Rammah y Hirschmann, is an important pest in tropical and subtropical countries, because it affects in natural way more than 30 different species like guava (Psidium guajava), coffee (Coffea spp.), vegetables, ornamental plants and weeds. Its distribution has been very fast due to anthropogenic factors, and the highest concern about this species is its capacity to infest and reproduce on resistant plants to Meloidogyne spp. This species has a high (more) variability in its perineal pattern morphology; thus the use of complementary elements like the offered by esterase profile is recommended. This specie has been found in mixed population with Meloidogyne incognita, Meloidogyne arenaria and Meloidogyne javanica, making more complex its diagnosis and management. Among the measurements to diminish its negative effect are the implementation of internal quarantine measures and the use of Cadusafos and Abermectine with variable results. In the same way, different research teams from Africa and America have evaluated extracts from Crotalaria spp., biological control agents (Arthrobotrys spp.), among other tactics. M. mayaguensis has been considered one of the most dangerous species of this genus. Its detection, right identification and contention in the areas in which it is found constitute one of the most important challenges for the sanitary authorities in the countries when the species has been reported. The opportune information and the effective training of the staff involved in the phytosanitary area represent a vital element for facing this emergent pest.

Rodríguez, Mayra G; Gómez, Lucila; Peteira, Belkis

2007-12-01

296

Major Emerging Problems with Minor Meloidogyne Species.  

UK PubMed Central (United Kingdom)

Root-knot nematodes (Meloidogyne spp.) represent one of the most polyphagous genera of plant-parasitic nematodes. To date, close to 100 valid species are recognized. In contrast to the size of the genus, the majority of past research focused on a small number of species, i.e., the so-called 'major' species M. arenaria, M. hapla, M. incognita, and M. javanica. This review highlights recent work aimed at 'minor' root-knot nematodes: M. chitwoodi, M. fallax, M. minor, M. enterolobii (=M. mayaguensis), and M. paranaensis. Some of these species have been described only recently. After a brief profile for each species, identification methods and their application in Meloidogyne spp. are summarized. Intraspecific variation and its impact on plant resistance breeding are discussed and interactions between M. enterolobii and Fusarium solani are highlighted as an example of synergistic interactions with other plant pathogens. Future research on Meloidogyne spp. is not only shaped by recent breakthroughs such as completing the genome sequences of M. hapla and M. incognita, but is also influenced by changes in agriculture. Taken together, the aim of this review is to draw attention to previously neglected and newly described Meloidogyne spp. that are developing into major problems for agriculture in tropical and temperate climates.

Elling AA

2013-06-01

297

Major Emerging Problems with Minor Meloidogyne Species.  

Science.gov (United States)

Root-knot nematodes (Meloidogyne spp.) represent one of the most polyphagous genera of plant-parasitic nematodes. To date, close to 100 valid species are recognized. In contrast to the size of the genus, the majority of past research focused on a small number of species, i.e., the so-called 'major' species M. arenaria, M. hapla, M. incognita, and M. javanica. This review highlights recent work aimed at 'minor' root-knot nematodes: M. chitwoodi, M. fallax, M. minor, M. enterolobii (=M. mayaguensis), and M. paranaensis. Some of these species have been described only recently. After a brief profile for each species, identification methods and their application in Meloidogyne spp. are summarized. Intraspecific variation and its impact on plant resistance breeding are discussed and interactions between M. enterolobii and Fusarium solani are highlighted as an example of synergistic interactions with other plant pathogens. Future research on Meloidogyne spp. is not only shaped by recent breakthroughs such as completing the genome sequences of M. hapla and M. incognita, but is also influenced by changes in agriculture. Taken together, the aim of this review is to draw attention to previously neglected and newly described Meloidogyne spp. that are developing into major problems for agriculture in tropical and temperate climates. PMID:23777404

Elling, Axel A

2013-06-18

298

Major emerging problems with minor meloidogyne species.  

UK PubMed Central (United Kingdom)

ABSTRACT Root-knot nematodes (Meloidogyne spp.) represent one of the most polyphagous genera of plant-parasitic nematodes. To date, close to 100 valid species are recognized. In contrast to the size of the genus, the majority of past research focused on a small number of species, i.e., the so-called 'major' species M. arenaria, M. hapla, M. incognita, and M. javanica. This review highlights recent work aimed at 'minor' root-knot nematodes: M. chitwoodi, M. fallax, M. minor, M. enterolobii (=M. mayaguensis), M. exigua, and M. paranaensis. Some of these species have been described only recently. After a brief profile of each species, identification methods and their application in Meloidogyne spp. are summarized. Intraspecific variation and its impact on plant resistance breeding are discussed and interactions between M. enterolobii and Fusarium solani are highlighted as an example of synergistic interactions with other plant pathogens. Future research on Meloidogyne spp. is not only shaped by recent breakthroughs such as completing the genome sequences of M. hapla and M. incognita, but is also influenced by changes in agriculture. Taken together, the aim of this review is to draw attention to previously neglected and newly described Meloidogyne spp. that are developing into major problems for agriculture in tropical and temperate climates.

Elling AA

2013-11-01

299

Differential Reaction of Alfalfa Cultivars to Meloidogyne hapla and M. chitwoodi Populations  

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Meloidogyne hapla reproduced and suppressed growth (P < 0.05) of susceptible Lahontan and Moapa alfalfa at 15, 20, and 25 C. At 30 C, resistant Nevada Syn XX lost resistance to M. hapla. M. hapla invaded and reproduced on Rhizobium meliloti nodules of Lahontan and Moapa, inducing giant cell formatio...

Griffin, G. D.; Inserra, R. N.; Vovlas, N.; Sisson, D. V.

300

Influence of Meloidogyne hapla on Alfalfa Yield and Host Population Dynamics  

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Self-thinning in alfalfa, a dynamic process involving the progressive elimination of the weakest plants, was enhanced by Meloidogyne hapla. Alfalfa stand densities decreased exponentially with time and were reduced 62% (P = 0.05) in the presence of M. hapla. As stand densities decreased over time, m...

Noling, J. W.; Ferris, H.

 
 
 
 
301

Preservation of Meloidogyne hapla and M. chitwoodi in liquid nitrogen : differences in response between populations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Une procédure est décrite pour la conservation de lignées de #Meloidogyne hapla$ et #M. chitwoodi$ dans l'azote liquide avec un prétraitement avec de l'éthanediol à 10% pendant 2 h à la température du laboratoire et avec de l'éthanediol à 40% pendant 45 min sur la glace. Les taux de survie varient d...

Van der Beek, H.J.G.; Veldhuis, W.B.J.; Zijlstra, C.; Van Silfhout, C.H.

302

Induced Resistance to Meloidogyne hapla by other Meloidogyne species on Tomato and Pyrethrum Plants.  

Science.gov (United States)

Advance inoculation of the tomato cv. Celebrity or the pyrethrum clone 223 with host-incompatible Meloidogyne incognita or M. javanica elicited induced resistance to host-compatible M. hapla in pot and field experiments. Induced resistance increased with the length of the time between inoculations and with the population density of the induction inoculum. Optimum interval before challenge inoculation, or population density of inoculum for inducing resistance, was 10 days, or 5,000 infective nematodes per 500-cm(3) pot. The induced resistance suppressed population increase of M. hapla by 84% on potted tomato, 72% on potted pyrethrum, and 55% on field-grown pyrethrum seedlings, relative to unprotected treatments. Pyrethrum seedlings inoculated with M. javanica 10 days before infection with M. hapla were not stunted, whereas those that did not receive the advance inoculum were stunted 33% in pots and 36% in field plots. The results indicated that advance infection of plants with incompatible or mildly virulent nematode species induced resistance to normally compatible nematodes and that the induced resistance response may have potential as a biological control method for plant nematodes. PMID:19277310

Ogallo, J L; McClure, M A

1995-12-01

303

Pathogenicity of Meloidogyne spp. (Tylenchida: Meloidogynidae) from Brazil and Central America on two genotypes of Coffea arabica/ Patogenicidade de Meloidogyne spp. (Tylenchida: Meloidogynidae) originárias do Brasil e América Central a dois genótipos de Coffea arabica  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Entre as espécies de nematóides de galhas mais danosas ao cafeeiro, Meloidogyne exigua, M. paranaensis, M. incognita, M. arabicida, M. izalcoensis e M. mayaguensis são as que causam os maiores problemas em áreas de cultivo de café no Brasil e países da América Latina. A reação de resistência a essas seis espécies foi estudada na progênie H 419-5-4-5-2, obtida do cruzamento artificial entre a cultivar Catuaí Amarelo IAC 30 com a seleção de Híbrido de Timor (more) UFV 445-46. As genótipos foram inoculados com 6.000 ovos/planta e o experimento foi conduzido no delineamento inteiramente ao acaso, com 10 repetições para cada espécie de Meloidogyne e cada genótipo de cafeeiro. A avaliação foi realizada 240 dias após a inoculação. O Fator de Reprodução (FR= População Final/6000) foi usado como variável para se avaliar a resistência. M. exigua causou galhas arredondadas típicas, sobretudo nas raízes novas. M. incognita, M. paranaensis e M. arabicida causaram engrossamento nas raízes, descolamento cortical e rachaduras em várias partes do sistema radicular.Nenhum sintoma foi observado para M. mayaguensis. M. izalcoensis causou galhas pequenas, a maioria na extremidade das raízes novas. As massas de ovos foram produzidas externamente e em grande número. O genótipo IAC 144 (testemunha) foi suscetível (FR>1.0) a todas espécies de Meloidogyne, exceto a M. mayaguensis. Esse isolado mostrou-se um parasita fraco para o cafeeiro. A progênie H 419-5-4-5-2 foi resistente a M. exigua e M. mayaguensis (FR Abstract in english Among the most damaging root-knot nematode species, Meloidogyne exigua, M. paranaensis, M. incognita, M. arabicida, M. izalcoensis and M. mayaguensis are major agronomic constraints in coffee-growing areas in Brazil and other Latin American countries. The resistance reaction to those six species was studied for the H 419-5-4-5-2 progeny, derived from the artificial hybridization between Catuaí Amarelo 'IAC 30' x Timor Hybrid UFV 445-46 selection. The Catuaí Vermelho IAC (more) 144 genotype was used as susceptibility control for Meloidogyne spp. The genotypes were inoculated with 6,000 eggs/plant and the experiment was set up in a completely randomized design, replicated 10 times for each Meloidogyne species and genotype. The evaluation was performed at 240 days after inoculation and the reproduction factor (RF= Final population/6000) was used as the variable to evaluate resistance. M. exigua caused typical rounded galls mostly on new roots, and egg-masses were produced mostly in the cortex under the root epidermis. M. incognita, M. paranaensis and M. arabicida caused swollen roots, peeling and cracking of cortical root tissue. No symptoms were observed for M. mayaguensis. M. izalcoensis induced very small galls, mostly on the extremity of new roots. Egg-masses were produced outside the roots in large quantities. The genotype IAC 144 was susceptible (FR>1.0) to all Meloidogyne spp. studied, except to M. mayaguensis. The nematode isolate used in this experiment seems to be a weak parasite for coffee. The H 419-5-4-5-2 progeny was resistant to M. exigua (FR

Carneiro, Regina M.D.G.; Mesquita, Luiz F.G. de; Gonçalves, Wallace; Pereira, Antônio A.

2008-08-01

304

Identification of Meloidogyne javanica Using Morphological and Morphometerical Characters and Species Specific Primers  

Directory of Open Access Journals (Sweden)

Full Text Available Root knot nematodes (Meloidogyne spp.) cause yield loss in all countries, of which, M. javanica, is the most widespread species in Iran. In order to identify M. javanica, 100 infected root and soil samples of root knot nematode were collected from different regions of Kerman province. After purification of populations and identification of M. javanica based on morphological and morphometerical characters of females and second stage juveniles (J2), total DNA was extracted from eggs, J2 and female adults. Specific 670 and 1600 bp bands were amplified in all M. javanica populations using species-specific primer pairs including OPARjav / OPAFjav and Mjavf / Mjavr These specific bands could not be amplified in other species such as M. incognita and M. arenaria. It seems that, application of these species specific primers in comparison with morphological characters would be more applicable, leading to easier identification of M. javanica.

H Askarian; B SHarifnabi; M Olia; E Mahdikhani; A Akhavan

2009-01-01

305

Host status of endophyte-infected and noninfected tall fescue grass to Meloidogyne spp.  

Science.gov (United States)

Tall fescue grass cultivars with or without endophytes were evaluated for their susceptibility to Meloidogyne incognita in the greenhouse. Tall fescue cultivars evaluated included, i) wild-type Jesup (E+, ergot-producing endophyte present), ii) endophyte-free Jesup (E-, no endophyte present), iii) ...

306

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

Science.gov (United States)

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

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

2013-05-13

307

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

UK PubMed Central (United Kingdom)

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.

Castagnone-Sereno P; Danchin EG; Perfus-Barbeoch L; Abad P

2013-01-01

308

Population dynamics of plant nematodes in cultivated soil: length of rotation in newly cleared and old agricultural land.  

UK PubMed Central (United Kingdom)

During a 6-year study of 1-, 2-, and 3-year crop rotations, population densities of Pratylenchus brachyurus, Trichodorus christiei, and Meloidogyne incognita were significantly affected by the choice of crops but not by length of crop rotation. The density of P. brachyurus and T. christiei increased rapidly on milo (Sorghum vulgate). In addition, populations of P. brachyurus increased significantly in cropping systems that involved crotalaria (C. rnucronata), millet (Setaria italica), and sudangrass (Sorghum sudanense). Lowest numbers of P. brachyurus occurred where okra (Hibiscus esculentus) was grown or where land was fallow. The largest increase in populations of T. christiei occurred in cropping systems that involved millet, sudangrass, and okra whereas the smallest increase occurred in cropping systems that involved crotalaria or fallow. A winter cover of rye (Secale cereale) had no distinguishable effect on population densities of P. brachyurus or T. christiei. Meloidogyne incognita was detected during the fourth year in both newly cleared and old agricultural land when okra was included in the cropping system. Detectable populations of M. incognita did not develop in any of the other cropping systems. Yields of tomato transplants were higher on the newly cleared land than on the old land. Highest yields were obtained when crotalaria was included in the cropping system. Lowest yields were obtained when milo, or fallow were included in the cropping system. Length of rotation had no distinguishable effect on yields of tomato transplants.

Good JM; Murphy WS; Brodie BB

1973-04-01

309

Population dynamics of plant nematodes in cultivated soil: length of rotation in newly cleared and old agricultural land.  

Science.gov (United States)

During a 6-year study of 1-, 2-, and 3-year crop rotations, population densities of Pratylenchus brachyurus, Trichodorus christiei, and Meloidogyne incognita were significantly affected by the choice of crops but not by length of crop rotation. The density of P. brachyurus and T. christiei increased rapidly on milo (Sorghum vulgate). In addition, populations of P. brachyurus increased significantly in cropping systems that involved crotalaria (C. rnucronata), millet (Setaria italica), and sudangrass (Sorghum sudanense). Lowest numbers of P. brachyurus occurred where okra (Hibiscus esculentus) was grown or where land was fallow. The largest increase in populations of T. christiei occurred in cropping systems that involved millet, sudangrass, and okra whereas the smallest increase occurred in cropping systems that involved crotalaria or fallow. A winter cover of rye (Secale cereale) had no distinguishable effect on population densities of P. brachyurus or T. christiei. Meloidogyne incognita was detected during the fourth year in both newly cleared and old agricultural land when okra was included in the cropping system. Detectable populations of M. incognita did not develop in any of the other cropping systems. Yields of tomato transplants were higher on the newly cleared land than on the old land. Highest yields were obtained when crotalaria was included in the cropping system. Lowest yields were obtained when milo, or fallow were included in the cropping system. Length of rotation had no distinguishable effect on yields of tomato transplants. PMID:19319315

Good, J M; Murphy, W S; Brodie, B B

1973-04-01

310

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

Directory of Open Access Journals (Sweden)

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.

Marina Capparelli Cadioli; Débora Cristina Santiago; Arian Derdote de Oliveira; Vanessa dos Santos Paes; Giovani de Oliveira Arieira; Fernando Cesar Baida

2009-01-01

311

Host Suitability of Twelve Leguminosae Species to Populations of Meloidogyne hapla and M. chitwoodi.  

Science.gov (United States)

Legumes of the genera Astragalus (milkvetch), Coronilla (crownvetch), Lathyrus (pea vine), Lotus (birdsfoot trefoil), Medicago (alfalfa), Melilotus (clover), Trifolium (clover), and Vicia (common vetch) were inoculated with a population of Melaidogyne chitwoodi from Utah or with one of three M. hapla populations from California, Utah, and Wyoming.Thirty-nine percent to 86% of alfalfa (M. scutellata) and 10% to 55% of red clover (T. pratense) plants survived inoculation with the nematode populations at a greenhouse temperature of 24 +/- 3 degrees C. All plants of the other legume species survived all nematode populations, except 4% of the white clover (T. repens) plants inoculated with the California M. hapla population. Entries were usually more susceptible to the M. hapla populations than to M. chitwoodi. Galling of host roots differed between nematode populations and species. Root-galling indices (1 = none, 6 = severely galled) ranged from 1 on pea vine inoculated with the California population of M. hapla to 6 on yellow sweet clover inoculated with the Wyoming population of M. hapla. The nematode reproductive factor (Rf = final nematode population/initial nematode population) ranged from 0 for all nematode populations on pea vine to 35 for the Wyoming population of M. hapla on alfalfa (M. sativa). PMID:19277158

Griffin, G D; Rumbaugh, M D

1996-09-01

312

Host Suitability of Twelve Leguminosae Species to Populations of Meloidogyne hapla and M. chitwoodi.  

UK PubMed Central (United Kingdom)

Legumes of the genera Astragalus (milkvetch), Coronilla (crownvetch), Lathyrus (pea vine), Lotus (birdsfoot trefoil), Medicago (alfalfa), Melilotus (clover), Trifolium (clover), and Vicia (common vetch) were inoculated with a population of Melaidogyne chitwoodi from Utah or with one of three M. hapla populations from California, Utah, and Wyoming.Thirty-nine percent to 86% of alfalfa (M. scutellata) and 10% to 55% of red clover (T. pratense) plants survived inoculation with the nematode populations at a greenhouse temperature of 24 +/- 3 degrees C. All plants of the other legume species survived all nematode populations, except 4% of the white clover (T. repens) plants inoculated with the California M. hapla population. Entries were usually more susceptible to the M. hapla populations than to M. chitwoodi. Galling of host roots differed between nematode populations and species. Root-galling indices (1 = none, 6 = severely galled) ranged from 1 on pea vine inoculated with the California population of M. hapla to 6 on yellow sweet clover inoculated with the Wyoming population of M. hapla. The nematode reproductive factor (Rf = final nematode population/initial nematode population) ranged from 0 for all nematode populations on pea vine to 35 for the Wyoming population of M. hapla on alfalfa (M. sativa).

Griffin GD; Rumbaugh MD

1996-09-01

313

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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 o (more) f 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

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

2012-04-01

314

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 élect...

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

315

Effects of biosolid amendment on populations of Meloidogyne hapla and soils with different textures and pHs.  

Science.gov (United States)

Temperate vegetable and nursery industries face significant challenges in managing Meloidogyne hapla, a plant-parasite for which few resistant cultivars and/or viable alternatives to methyl bromide exist. N-Viro Soil(R) (NVS), an alkaline-stabilized biosolid product, has soil nutrition enrichment capacity and potential for plant-parasitic nematode suppression. In three sets of experiments, we investigated the effects of NVS on M. hapla populations from Rhode Island (RI), Connecticut (CT), New York, Geneva (NYG) and Lyndonville (NYL), and Michigan (MI), and growth of tomato cv 'Rutgers' in five soils commonly used for vegetable and nursery crop production in the Great Lakes Region of the USA. Either 0 (control) or 600 eggs/100 cm(3) of soil per M. hapla population were added in all experiments. In the first set, NVS was applied at rates of 0, 1, 2 and 4 g/100 cm(3) of sandy loam soil (pH 7) and resulted in variable responses on the numbers of nematodes recovered and plant growth at 30 and 90 days (25+/-2 degrees C); however, the 2g NVS treatment consistently increased plant growth. Either 0 or 2 NVS/100 cm(3) were applied to a coarse loamy (pH 4.5) and sandy loam (pH 8, second set of experiments), and muck (pH 5.5), loamy sand (pH 7.1) and sandy loam (pH 7.5, third set of experiments) soils and experiments terminated four weeks after nematode inoculation. Across experiments, the effect of NVS on the M. hapla populations varied. Generally nematode infection decreased plant growth. NVS increased soil pH the most in muck and the least in sandy loam soil. The most consistent interaction effects of NVS*soil, NVS*M. hapla, soil*M. hapla and/or NVS*soil*M. hapla across the experiments indicate that NVS affects M. hapla populations in different ways in different soil types, suggesting that NVS application is likely to be site-specific. These findings further provide basis that may potentially explain reports of variable effects of NVS on nematodes and how future studies may account in furthering our understanding of NVS activities for M. hapla management. PMID:20427181

Mennan, Sevilhan; Melakeberhan, Haddish

2010-04-27

316

Effects of biosolid amendment on populations of Meloidogyne hapla and soils with different textures and pHs.  

UK PubMed Central (United Kingdom)

Temperate vegetable and nursery industries face significant challenges in managing Meloidogyne hapla, a plant-parasite for which few resistant cultivars and/or viable alternatives to methyl bromide exist. N-Viro Soil(R) (NVS), an alkaline-stabilized biosolid product, has soil nutrition enrichment capacity and potential for plant-parasitic nematode suppression. In three sets of experiments, we investigated the effects of NVS on M. hapla populations from Rhode Island (RI), Connecticut (CT), New York, Geneva (NYG) and Lyndonville (NYL), and Michigan (MI), and growth of tomato cv 'Rutgers' in five soils commonly used for vegetable and nursery crop production in the Great Lakes Region of the USA. Either 0 (control) or 600 eggs/100 cm(3) of soil per M. hapla population were added in all experiments. In the first set, NVS was applied at rates of 0, 1, 2 and 4 g/100 cm(3) of sandy loam soil (pH 7) and resulted in variable responses on the numbers of nematodes recovered and plant growth at 30 and 90 days (25+/-2 degrees C); however, the 2g NVS treatment consistently increased plant growth. Either 0 or 2 NVS/100 cm(3) were applied to a coarse loamy (pH 4.5) and sandy loam (pH 8, second set of experiments), and muck (pH 5.5), loamy sand (pH 7.1) and sandy loam (pH 7.5, third set of experiments) soils and experiments terminated four weeks after nematode inoculation. Across experiments, the effect of NVS on the M. hapla populations varied. Generally nematode infection decreased plant growth. NVS increased soil pH the most in muck and the least in sandy loam soil. The most consistent interaction effects of NVS*soil, NVS*M. hapla, soil*M. hapla and/or NVS*soil*M. hapla across the experiments indicate that NVS affects M. hapla populations in different ways in different soil types, suggesting that NVS application is likely to be site-specific. These findings further provide basis that may potentially explain reports of variable effects of NVS on nematodes and how future studies may account in furthering our understanding of NVS activities for M. hapla management.

Mennan S; Melakeberhan H

2010-09-01

317

Circumscribed alopecia areata incognita.  

UK PubMed Central (United Kingdom)

The characteristic lesion of alopecia areata is a smooth bald patch on the scalp. When there is no bald surface it is called alopecia areata incognita. To date, all cases of alopecia areata reported as so-called 'incognito' have shown a diffuse involvement of the scalp as in acute telogen effluvium. Recently, we have observed two patients who showed localised hair thinning of the scalp without bald spots. Histopathologically, the lesions were typical of alopecia areata with peribulbar lymphocytic infiltrates. The response to corticosteroid treatment and its clinical course were also compatible with alopecia areata.

Park J; Song KH; Nam KH

2013-02-01

318

Spring or Fall Fumigation for Control of Meloidogyne spp. on Tobacco.  

UK PubMed Central (United Kingdom)

Tests were conducted in 1987-88 to compare the efficacy of spring or fall fumigant nematicide applications for control ofMeloidogyne arenaria and M. incognita on tobacco. Chloropicrin, 1,3-D, methyl isothiocyanate, and a methyl isothiocyanate-l,3-D mixture were applied as row treatments. Fenamiphos, fenamiphos + fensulfothion, or ethoprop were applied in the spring as nonfumigant nematicide standards. Fumigant nematicides increased yields and reduced galling (P = 0.01) in all four tests. Spring or fall applications of fumigant nematicides were effective in controlling M. arenaria and M. incognita and were superior to the nonfumigant nematicides tested.

Fortnum BA; Gooden DT; Currin RE; Martin SB

1990-10-01

319

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  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 Meloid (more) ogyne 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. Abstract in english 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 tre (more) es (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.

Cadioli, Marina Capparelli; Santiago, Débora Cristina; Oliveira, Arian Derdote de; Paes, Vanessa dos Santos; Arieira, Giovani de Oliveira; Baida, Fernando Cesar

2009-06-01

320

SINTOMATOLOGÍA Y ESPECIES DE Meloidogyne ASOCIADAS A VID (Vitis vinifera L. cv. Aramond) EN GÜIRA DE MELENA, ARTEMISA. (Resultados preliminares)/ SYMPTOMATOLOGY AND SPECIES OF Meloidogyne ASSOCIATED WITH GRAPEVINE (Vitis vinifera L. cv. Aramond) IN GÜIRA DE MELENA, Artemisa. (Preliminary results)  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Un viñedo (Vitis vinifera L. cv. Aramond) de 21 años de plantado mostraba síntomas semejantes a los producidos por la presencia de nematodos formadores de agallas (Meloidogyne spp.), así como mermas en los rendimientos. En visita realizada a la plantación, se constató la existencia de áreas con plantas cloróticas y con diversos grados de defoliación. Las bases de los tallos mostraban rajaduras longitudinales y ensanchamientos en la región que se encontraba por e (more) ncima de la superficie del suelo. Al examinar las raíces se encontraron agallas de diversos tamaños y la pérdida de volúmenes importantes de raíces secundarias. En las agallas, se encontraron hembras adultas de Meloidogyne con ootecas desarrolladas, y el estudio de los patrones perineales de estas hembras evidenció la presencia de especímenes de tres especies (Meloidogyne arenaria (Neal) Chitwood, Meloidogyne incognita (Kofoid & White) Chitwood y Meloidogyne javanica (Trueb) Chitwood), mientras otros fueron ubicados en la categoría de Meloidogyne spp., hasta completar los estudios moleculares. Del total de especímenes examinados, M. arenaria mostró ser componente mayoritario de la comunidad con un 53%, seguido de M. incognita (21%) y M. javanica (4%). La presencia de M. arenaria en vid, representa el primer informe de la especie en este cultivo en Cuba y constituye foco de atención para el servicio fitosanitario, por ser una de las plagas más importante para la vid a nivel mundial. Abstract in english A 21 year old vineyard (Vitis vinifera L. cv. Aramond) showed symptoms similar to those caused by the root knot nematodes (Meloidogyne spp.) as well as decreases in yield. In a visit to the area, several chlorotic plants with different degree of defoliation were observed. The stem bases above the soil surface were swollen and they showed longitudinal cracks. Galls of different sizes were observed on the roots with significant losses of secondary roots. Adult females of Me (more) loidogyne with well developed egg masses were found inside the galls. The study of the perineal patterns of these females showed the presence of specimens belonging to three species (Meloidogyne arenaria (Neal) Chitwood, Meloidogoyne incognita (Kofoid & White) Chitwood and Meloidogyne javanica (Trueb) Chitwood), as well as others that were grouped as Meloidogyne spp. until completing the molecular studies of all the specimens observed. M. arenaria showed to be the majority component of the community with 53%, followed by M. incognita and M. javanica with 21% and 4% respectively. The presence of M. arenaria in grapevine is the first report of this specie in the crop in Cuba and constitutes a focus of attention for the plant protection service because it is one of the most important pests in grapevine in the world.

Rodríguez, Mayra G; Hernández, Dainé; Enrique, R; Gómez, Lucila; Díaz-Viruliche, Luisa; Peteira, Belkis

2011-08-01

 
 
 
 
321

Morphological, Molecular, and Differential-Host Characterization of Meloidogyne floridensis n. sp. (Nematoda: Meloidogynidae), a Root-Knot Nematode Parasitizing Peach in Florida  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A root-knot nematode, Meloidogyne floridensis n. sp., is described and illustrated from peach originally collected from Gainesville, Florida. This new species resembles M. incognita, M. christiei, M. graminicola, and M. hispanica, but with LM and SEM observations it differs from these species either...

Handoo, Z. A.; Nyczepir, A. P.; Esmenjaud, D.; van der Beek, J. G.; Castagnone-Sereno, P.; Carta, L. K.; Skantar, A. M.

322

Morphological, molecular, and differential-host characterization of Meloidogyne floridensis n. sp (Nematoda : Meloidogynidae), a root-knot nematode parasitizing peach in Florida  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A root-knot nematode, Meloidogyne floridensis n. sp., is described and illustrated from peach originally collected from Gainesville, Florida. This new species resembles M. incognita, M. christiei, M. graminicola, and M. hispanica, but with LM and SEM observations it differs from these species either...

Handoo, Z.A.; Nyczepir, A.P.; Esmenjaud, D.; Beek, J.G., van; Castagnone-Sereno, P.; Carta, L.K.; Skantar, A.M.; Higgins, J.A.

323

Resistance verification in Prunus selections to a mixture of thirteen Meloidogyne isolates and resistance mechanisms of a peach-almond hybrid to M. javanica  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Treize isolats de #Meloidogyne$ originaires d'Espagne comprenant #M. incognita$ (six), #M. arenaria$ (six) et #M. javanica$ (trois) ont été utilisés pour vérifier le niveau de résistance de douze porte-greffe de #Prunus$. La majorité de ces porte-greffe était constituée d'hybrides pêcher-amandier en...

Marull, J.; Pinochet, J.; Felipe, A.; Cenis, J.L.

324

Response of some common annual bedding plants to three species of meloidogyne.  

UK PubMed Central (United Kingdom)

Twelve ornamental bedding plant cultivars were grown in soil infested with isolates of Meloidogyne incognita race 1, M. javanica, or M. arenaria race 1 in a series of tests in containers in a growth room. Root galling (0-5 scale) and eggs/plant were evaluated 8-10 weeks after soil infestation and seedling transplantation. Snapdragon, Antirrhinum majus cv. First Ladies, was extensively galled and highly susceptible (mean gall rating >/=4.2 and >/=14,500 eggs/plant), and Celosia argentea cv. Century Mix and Coleus blumei cv. Rainbow were susceptible (>1,500 eggs/plant) to all three Meloidogyne isolates. Response of Petunia x hybrida varied with cultivar and nematode isolate. Little or no galling or egg production from any Meloidogyne isolate was observed on Ageratum houstonianum cv. Blue Mink, Lobularia maritima cv. Rosie O'Day, or Tagetes patula cv. Dwarf Primrose. Galling was slight (mean rating 4.0 and >/=7,900 eggs/plant) by M. javanica and M. arenaria but was nearly free of galling from M. incognita. Zinna elegans cv. Scarlet was nearly free of galling from M. incognita and M. arenaria but was susceptible (mean gall rating = 2.9; 3,400 eggs/plant) to M. javanica.

McSorley R; Frederick JJ

1994-12-01

325

Response of some common annual bedding plants to three species of meloidogyne.  

Science.gov (United States)

Twelve ornamental bedding plant cultivars were grown in soil infested with isolates of Meloidogyne incognita race 1, M. javanica, or M. arenaria race 1 in a series of tests in containers in a growth room. Root galling (0-5 scale) and eggs/plant were evaluated 8-10 weeks after soil infestation and seedling transplantation. Snapdragon, Antirrhinum majus cv. First Ladies, was extensively galled and highly susceptible (mean gall rating >/=4.2 and >/=14,500 eggs/plant), and Celosia argentea cv. Century Mix and Coleus blumei cv. Rainbow were susceptible (>1,500 eggs/plant) to all three Meloidogyne isolates. Response of Petunia x hybrida varied with cultivar and nematode isolate. Little or no galling or egg production from any Meloidogyne isolate was observed on Ageratum houstonianum cv. Blue Mink, Lobularia maritima cv. Rosie O'Day, or Tagetes patula cv. Dwarf Primrose. Galling was slight (mean rating 4.0 and >/=7,900 eggs/plant) by M. javanica and M. arenaria but was nearly free of galling from M. incognita. Zinna elegans cv. Scarlet was nearly free of galling from M. incognita and M. arenaria but was susceptible (mean gall rating = 2.9; 3,400 eggs/plant) to M. javanica. PMID:19279963

McSorley, R; Frederick, J J

1994-12-01

326

Inheritance of Resistance to Meloidoygne incognita in Primitive Cotton Accessions from Mexico  

Science.gov (United States)

Few sources of resistance to root-knot nematodes (Meloidogyne incognita) in upland cotton (Gossypium hirsutum) have been utilized to develop resistant cultivars, making this resistance vulnerable to virulence in the pathogen population. The objectives of this study were to determine the inheritance of resistance in five primitive accessions of G. hirsutum (TX1174, TX1440, TX2076, TX2079, and TX2107) and to determine allelic relations with the genes for resistance in the genotypes Clevewilt-6 (CW) and Wild Mexico Jack Jones (WMJJ). A half-diallel experimental design was used to create 28 populations from crosses among these seven sources of resistance and the susceptible cultivar DeltaPine 90 (DP90). Resistance to M. incognita was measured as eggs per g roots in the parents, F1 and F2 generations of each cross. The resistance in CW and WMJJ was inherited as recessive traits, as reported previously for CW, whereas the resistance in the TX accessions was inherited as a dominant trait. Chi square analysis of segregation of resistance in the F2 was used to estimate the numbers of genes that conditioned resistance. Resistance in CW and WMJJ appeared to be a multigenic trait whereas the resistance in the TX accessions best fit either a one or two gene model. The TX accessions were screened with nine SSR markers linked to resistance loci in other cotton genotypes. The TX accessions lacked the allele amplified by SSR marker CR316 and linked to resistance in CW and other resistant genotypes derived from this source. Four of five TX genotypes lacked the amplification products from the marker BNL1231 that is also associated with the resistant allele on Chromosome 11 in WMJJ, CW, NemX, M120 RNR and Auburn 634 RNR. However, all five TX genotypes produced the same amplification products from three SSR markers linked to the resistant allele on Chromosome 14 in M120 RNR and M240 RNR. The TX accessions have unique resistance genes that are likely to be useful in efforts to develop resistant cotton cultivars with increased durability.

Moresco, E. R.; Smith, C. W.; Nichols, R. L.; Roberts, P. A.; Chee, P.

2010-01-01

327

Relationships between agro-ecological factors and population densities of Meloidogyne exigua and Pratylenchus coffeae sensu lato in coffee roots, in Costa Rica  

UK PubMed Central (United Kingdom)

Controlling coffee nematodes using fewer pesticides is a priority for most producing countries. The aim of this study was to identify ecological and agricultural factors associated with Meloidogyne exigua and Pratylenchus coffeae sensu lato population densities in coffee roots. The influence of these factors was studied in a two-year survey by characterizing 57 coffee plots in five major producing regions in Costa Rica, where coffee is generally cultivated in intensified systems. Correspondence analyses and Chi-squared automatic interaction detector (CHAID) classification trees were used to identify and classify the ecological and agricultural factors associated with nematode population densities. M. exigua and P. coffeae population densities were opposites with respect to soil characteristics. Low M. exigua population densities were especially found in soils with low sand and high Zn and K contents. The opposite was seen for P. coffeae. In addition, M. exigua and P. coffeae seemed to have different climatic requirements: M. exigua was mainly found at lower altitudes than P. coffeae. Consequently and through possible competition phenomena between P. coffeae and M. exigua, a negative correlation was found between the two nematode population densities on a plot scale. We found only one cropping practice that seemed to affect both nematodes similarly: a within-row distance between coffee trees of less than 0.9m was associated with large M. exigua and P. coffeae population densities. The results of this study provide further evidence of the greater intensity of pest and disease attacks in intensified coffee systems.

Avelino Jacques; Bouvret Marie-Elsie; Salazar Luis; Cilas Christian

2009-09-01

328

Algumas plantas hospedeiras de nematóides do gênero Meloidogyne/ Host plants of root-knot nematodes  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Coletaram-se plantas do gênero Coffea e de diversas ervas daninhas, as quais foram examinadas em laboratório visando verificar a ocorrência de nematóides do gênero Meloidogyne Goeldi, 1887. As plantas parasitadas por M. exigua, M. incognita, M. arenaria e por uma espécie não identificada, referida como Meloidogyne sp., são. apresentadas. Indicam-se os hospedeiros novos de alguns dos nematóides mencionados e confirma-se o parasitismo de outras plantas, nas condições estudadas. Abstract in english Root-knot nematodes were found attacking Coffea spp. and also roots of a few weed species usually found in the coffee orchards in São Paulo. C. arabica cv. Catuaí, C. arabica cv. Mundo Novo, Timor Hybrid and a few plants of C. racemosa showed to be susceptible to Meloidogyne exigua. Roots of Ageratum conyzoides, Amaranthus viridis, Bidens pilosa, Coffea arabica cv. Mundo Novo, Coffea racemosa, Commelina virginica, Digitaria sanguinalis, Galinsoga parviflora, Gnaphalium (more) spathulatum, Porophyllum ruderale, Portulaca oleracea, Pterocaulon virgatum and Solanum americanum were disfigured by M. incognita M. arenaria was found attacking roots of Eleusine indica and Gnaphalium spathulatum, and the presence of an unidentified Meloidogyne species was verified in roots of the following species: Vernonia ferruginea, C. arabica x C. canephora, Eupatorium pauciflorum, Coffea canephora cv. Kouillou, Coffea eugenioides, Coffea racemosa, Coffea stenophylla, Euphorbia pilullifera, Solanum americanum, Ageratum conyzoides, Phyllanthus corcovadensis, and Emilia sagittata.

Lordello, Luiz Gonzaga E.; Fazuoli, Luiz Carlos; Aranha, Condorcet; Lordello, Rubens R.A.

1975-01-01

329

RKN Lethal DB: A database for the identification of Root Knot Nematode (Meloidogyne spp.) candidate lethal genes.  

UK PubMed Central (United Kingdom)

UNLABELLED: Root Knot nematode (RKN; Meloidogyne spp.) is one of the most devastating parasites that infect the roots of hundreds of plant species. RKN cannot live independently from their hosts and are the biggest contributors to the loss of the world's primary foods. RNAi gene silencing studies have demonstrated that there are fewer galls and galls are smaller when RNAi constructs targeted to silence certain RKN genes are expressed in plant roots. We conducted a comparative genomics analysis, comparing RKN genes of six species: Meloidogyne Arenaria, Meloidogyne Chitwoodi, Meloidogyne Hapla, Meloidogyne Incognita, Meloidogyne Javanica, and Meloidogyne Paranaensis to that of the free living nematode Caenorhabditis elegans, to identify candidate genes that will be lethal to RKN when silenced or mutated. Our analysis yielded a number of such candidate lethal genes in RKN, some of which have been tested and proven to be effective in soybean roots. A web based database was built to house and allow scientists to search the data. This database will be useful to scientists seeking to identify candidate genes as targets for gene silencing to confer resistance in plants to RKN. AVAILABILITY: The database can be accessed from http://bioinformatics.towson.edu/RKN/

Ismail A; Matthews BF; Alkharouf NW

2012-01-01

330

RKN Lethal DB: A database for the identification of Root Knot Nematode (Meloidogyne spp.) candidate lethal genes  

Directory of Open Access Journals (Sweden)

Full Text Available Root Knot nematode (RKN; Meloidogyne spp.) is one of the most devastating parasites that infect the roots of hundreds of plant species. RKN cannot live independently from their hosts and are the biggest contributors to the loss of the world's primary foods. RNAi gene silencing studies have demonstrated that there are fewer galls and galls are smaller when RNAi constructs targeted to silence certain RKN genes are expressed in plant roots. We conducted a comparative genomics analysis, comparing RKN genes of six species: Meloidogyne Arenaria, Meloidogyne Chitwoodi, Meloidogyne Hapla, Meloidogyne Incognita, Meloidogyne Javanica, and Meloidogyne Paranaensis to that of the free living nematode Caenorhabditis elegans, to identify candidate genes that will be lethal to RKN when silenced or mutated. Our analysis yielded a number of such candidate lethal genes in RKN, some of which have been tested and proven to be effective in soybean roots. A web based database was built to house and allow scientists to search the data. This database will be useful to scientists seeking to identify candidate genes as targets for gene silencing to confer resistance in plants to RKN.

Ahmed Ismail; Benjamin F Matthews; Nadim W Alkharouf

2012-01-01

331

Resistance to Meloidogyne hapla in Peanut.  

UK PubMed Central (United Kingdom)

Two hundred thirty-five cultivated varieties, breeding lines and plant introductions of Arachis hypogaea and 12 accessions of wild Arachis spp. were tested for resistance to Meloidogyne hapla. Eight of the cultivated peanut lines were only moderately susceptible and four of the wild peanuts exhibited resistance. No resistance-breaking M. hapla populations were found among 10 geographical isolates tested.

Castillo MB; Morrison LS; Russell CC; Banks DJ

1973-10-01

332

CONTROL OF MELOIDOGYNE MARYLANDI ON BERMUDA GRASS  

Science.gov (United States)

Meloidogyne marylandi is widely distributed on turf in Texas and is frequently associated with poor turf appearance and growth. Suppression of population densities of M. marylandi on established Bermudagrass through application of a new formulation of 1,3-dichloropropene (Curfew), fenamiphos (Nemacu...

333

Efecto de diferentes densidades poblacionales de Meloidogyne hapla sobre uchuva (Physalis peruviana L.) en invernadero/ Effect of different population densities of Meloidogyne hapla on the cape gooseberry (Physalis peruviana L.) in greenhouse  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish 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 bio (more) masa 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 (?=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-m)Z P-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. Abstract in english A trial was conducted at the Center of Investigations and Agroindustrial Accessory of the University Jorge Tadeo Lozano, Chía (Cundinamarca) under greenhouse condition during ten months of cultivation. The effect of different population densities of M. hapla (0, 50, 100, 200, 500 and 1,000 larvae J2/100 cc soil) on productive parameters of the cape gooseberry, such as plant height, stem diameter, fresh and dry weights of leaves, fresh weight of roots, root nodulation ind (more) ex and weight of fruits in four harvests were evaluated. A variance analysis, contrasts test and Tukey test, within a randomized design with six treatments, and five repetitions was done within SAS v.8.0 program. It was determined that a treatment 500 larvae J2/100 cc soil had the highest effect on the plant height, stem diameter, leaf biomass and fresh weight of roots, besides it showed the highest root nodulation index. There were no significant differences found among the treatments for fresh weight and dry weight of leaves and fruits weight. For J2 larvae’s number in soil and eggs mass, the differences among the treatments inoculated with M. hapla were not found. A tolerance limit of 50 larvas J2/l00 cc soil was derived from fitting the data of root fresh weight and a tolerance limit of 450 larvas J2/l00 cc soil from data of biomass using the equation Y=m+(1-m)Z P-T proposed by Seinhorst (1965).

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

2008-04-01

334

Hermaphroditism in Meloidogyne hapla.  

UK PubMed Central (United Kingdom)

Hermaphrodites were detected in diploid and polyploid isolates of population 86-Va of Meloidogyne hapla. Young hermaphrodites are indistinguishable from normal females. Initially, hermaphrodite ovaries are filled with oocytes at various stages of development. Hermaphroditism is expressed later when young oocytes in the early pachytene region of the growth zone suddenly advance to diakinesis and proceed with maturation divisions, resulting in spermatid production. Spermatogenesis may be initiated shortly after the fourth molt, or later, after a female has produced some eggs. Spermatogenesis may occur in one or both gonads, and it may be initiated in one gonad before the other. Once initiated, spermatogenesis continues for the entire reproductive life of the hermaphrodite. Several thousand spermatozoa accumulate in the ovotestis. Because they do not pass through the oviduct into the spermatotheca, they do not take part in reproduction (nonfunctional hermaphroditism). Among the progeny of hermaphrodites, ca. 50% are hermaphroditic, and the remainder are apparently normal females which, however, produce about 50% hermaphroditic progeny. Two temperature regimes (20-23 C and 27-30 C) did not influence the percentage of hermaphrodites among the progeny. Hermaphroditism could not be transmitted to nonhermaphroditic isolates following attempted crosses between males of hermaphroditic and females of nonhermaphroditic isolates. Although this result suggests cytoplasmic rather than nuclear inheritance, this conclusion is not definitive.

Triantaphyllou AC

1993-03-01

335

Hermaphroditism in Meloidogyne hapla.  

Science.gov (United States)

Hermaphrodites were detected in diploid and polyploid isolates of population 86-Va of Meloidogyne hapla. Young hermaphrodites are indistinguishable from normal females. Initially, hermaphrodite ovaries are filled with oocytes at various stages of development. Hermaphroditism is expressed later when young oocytes in the early pachytene region of the growth zone suddenly advance to diakinesis and proceed with maturation divisions, resulting in spermatid production. Spermatogenesis may be initiated shortly after the fourth molt, or later, after a female has produced some eggs. Spermatogenesis may occur in one or both gonads, and it may be initiated in one gonad before the other. Once initiated, spermatogenesis continues for the entire reproductive life of the hermaphrodite. Several thousand spermatozoa accumulate in the ovotestis. Because they do not pass through the oviduct into the spermatotheca, they do not take part in reproduction (nonfunctional hermaphroditism). Among the progeny of hermaphrodites, ca. 50% are hermaphroditic, and the remainder are apparently normal females which, however, produce about 50% hermaphroditic progeny. Two temperature regimes (20-23 C and 27-30 C) did not influence the percentage of hermaphrodites among the progeny. Hermaphroditism could not be transmitted to nonhermaphroditic isolates following attempted crosses between males of hermaphroditic and females of nonhermaph