Interactions of Heterodera daverti, H. goldeni and H. zeae with Meloidogyne incognita on rice

Science.gov (United States)

The interactions of the cyst nematodes Heterodera daverti, H. goldeni and H. zeae with the root-knot nematode Meloidogyne incognita on rice (Oryza sativa) cultivars Giza 178 and Sakha 101 were studied in the greenhouse. Inoculation with H. goldeni alone or one week before inoculation with M. incogni...

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

Science.gov (United States)

Kokalis-Burelle, Nancy

2015-09-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

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Vergel German

1979-06-01

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

Potensi Jamur Parasit Telur Sebagai Agens Hayati Pengendali Nematoda Puru Akar Meloidogyne incognita pada Tanaman Tomat

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Siwi Indarti

2014-12-01

Full Text Available Root-knot nematodes Meloidogyne spp. are sedentary endoparasitic that attacks various economically important plants. Utilization of nematode’s fungal egg parasite as biocontrol agents of sedentary endoparasitic nematodes have a good possibility of potential success to be applied in the field level, because this fungi is able to colonize in and causes damage to eggs as well as female nematodes inside the root. The purpose of this research are to know the parasitism ability of this parasitic fungi to Meloidogyne incognita eggs, and its effects on second stage larvae hatching rate and the development of galls number in the host. The result shows that the parasitic fungi, those of Trichoderma, Penicillium, Talaromyces, Fusarium genera were able to parasitize root-knot nematode eggs (25.09 to 89.79%, caused root-knot nematode egg hatching to decrease, suppressed the formation of galls, and reduced the population of second stage nematode larvae in the greenhouse. Nematoda puru-akar Meloidogyne spp. adalah nematoda endoparasitik sedentari, bersifat polifag, dan mempunyai nilai ekonomi tinggi. Pemanfaatan jamur parasit telur sebagai agens hayati pengendali nematoda endoparasitik sedentari mempunyai potensi tingkat keberhasilan tinggi untuk diterapkan pada aras lapangan karena mampu mengoloni dan merusak telur maupun stadium nematoda betina yang terlindungi jaringan tanaman. Tujuan penelitian adalah untuk mengetahui kemampuan parasitasi isolat-isolat jamur parasit telur terhadap telur nematoda Meloidogyne incognita, dan pengaruhnya terhadap tingkat penetasan telur menjadi L-2, serta pembentukan jumlah puru pada tanaman terserang. Hasil penelitian didapatkan bahwa jamur parasit telur yang termasuk genera Tricoderma, Penicillium, Talaromyces, dan Fusarium mampu memarasit telur M. incognita berkisar antara 25,09–89,79%, mengakibatkan penurunan persentase jumlah L-2 nematoda yang bersangkutan, serta menekan pembentukan puru akar pada aplikasi aras

FUNGOS MICORRÍZICOS ARBUSCULARES NO CONTROLE DE Meloidogyne incognita EM MUDAS DE TOMATEIRO

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CARLA DA SILVA SOUSA

2010-01-01

Full Text Available Mycorrhizal fungi has been shown to affect some species of parasitic nematodes, in many cases reducing oviposition and the number of galls on the root system of infected plants. In order to evaluate the biocontrol potential of arbuscular mycorrhizal fungi to reduce the infectivity of Meloidogyne incognita in tomato plants, an experiment was conducted with a randomized block design with eight replications in a factorial with thefollowing treatments: with and without M . incognita, with presence and absence of fungal species Glomus clarum Nicolson & Schenck, Gigaspora albida Schanck & amp; Smith and Acaulospora scrobiculata Trappe. The fungus G. clarum significantly reduced the gall index (46.4% and the number of egg mass (78.8% of the nematode on tomato seedlings. The percentage of root colonization is not in itself an indicator of efficiency in controlling fungal infectivity of M. incognita in tomato plants, since A. scrobiculata exhibited a high degree of colonization (77.6% and was not effective in controlling nematode reproduction. The species of mycorrhizal fungi differ in efficiency in reducing the infectivity of M. incognita in tomato seedlings.

Toxicity of manipueira to Meloidogyne incognita in soybean

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Wéverson Lima Fonseca

2016-12-01

Full Text Available Manipueira, a liquid residue obtained from the cassava industrialization, shows high toxicity to the microbial diversity. This study aimed at evaluating the potential of manipueira applied to the soil to control Meloidogyne incognita in soybean. A completely randomized design, in a 2 x 11 factorial scheme, was used, consisting of two application forms of manipueira (single and two applications, in eleven concentrations (0 %, 10 %, 20 %, 30 %, 40 %, 50 %, 60 %, 70 %, 80 %, 90 % and 100 %, with five replications per treatment. Some agronomic traits and parasitism characteristics were also evaluated. The plants that received a single application of manipueira showed a gain of 100.41 % in root length, while the volume and fresh root mass showed gains of 81.52 % and 28.11 %, respectively, with the two applications. Regarding parasitism, the single application was more effective in reducing the number of juveniles in the soil and roots, where the concentrations of manipueira to kill 50 % of the nematodes were 1.65 % and 4.37 %, respectively. Thus, besides being effective in controlling M. incognita, manipueira has a positive effect on the development of soybean and may be recommended as a nematicide and also as an organic fertilizer.

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

Science.gov (United States)

Tedford, E C; Fortnum, B A

1988-10-01

Thirty-two weed species common in South Carolina and one cultivar of tobacco were evaluated as hosts of Meloidogyne arenaria race 2 and M. incognita race 3 in the greenhouse. Egg mass production and galling differed (P 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.

Development of enzyme linked immunosorbent assay (ELISA) for the detection of root-knot nematode Meloidogyne incognita.

Science.gov (United States)

Kapur-Ghai, J; Kaur, M; Goel, P

2014-09-01

Root-knot nematodes (Meloidogyne incognita) are obligate, sedentary plant endoparasites that are extremely polyphagous in nature and cause severe economic losses in agriculture. Hence, it is essential to control the parasite at an early stage. For any control strategy to be effective, an early and accurate diagnosis is of paramount importance. Immunoassays have the inherent advantages of sensitivity and specificity; have the potential to identify and quantify these plant-parasitic nematodes. Hence, in the present studies, enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of M.incognita antigens. First an indirect ELISA was developed for detection and titration of anti-M.incognita antibodies. Results indicated as high as 320 K titre of the antisera. Finally competitive inhibition ELISA was developed employing these anti-M.incognita antibodies for detection of M.incognita antigens. Sensitivity of ELISA was 10 fg. Competitive inhibition ELISA developed in the present studies has the potential of being used as an easy, rapid, specific and sensitive diagnostic tool for the detection of M.incognita infection.

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

Science.gov (United States)

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

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

NARCIS (Netherlands)

Mustika, I.

1990-01-01

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

Management of Meloidogyne incognita on tomato with endophytic bacteria and fresh residue of Wasabia japonica.

Science.gov (United States)

Li, G J; Dong, Q E; Ma, L; Huang, Y; Zhu, M L; Ji, Y P; Wang, Q H; Mo, M H; Zhang, K Q

2014-10-01

To characterize the nematicidal endophytic bacteria (NEB) of Wasabia japonica (wasabi) and evaluated the control efficacies of promising NEB as well as fresh wasabi residue (FWR) against Meloidogyne incognita on tomato. By in vitro bioassay, 53 NEB strains showing nematicidal efficacies of >50% against J2 of M. incognita were isolated from wasabi. Basing on 16S rRNA gene sequences, these NEB were identified into 18 species of 11 genera. In greenhouse, incorporation of selected NEB culture or FWR into potted soil significantly reduced infection of M. incognita on tomato. Treating tomatoes with either FWR or NEB of Raoultella terrigena RN16 and Pseudomonas reinekei SN21 in the field yielded excellent control efficacies against M. incognita, especially the combinations of FWR with either R. terrigena RN16 or Ps. reinekei SN21 at doses of 50 g plus 100 ml per plant or more. The results established that R. terrigena RN16 and Ps. reinekei SN21 applied separately or combined with FWR have the potential to provide bioprotection agents against M. incognita. This study provides novel way for disease management using combination of endophyte and host residue. © 2014 The Society for Applied Microbiology.

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

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

2013-01-01

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

Parasitic nematode Meloidogyne incognita interactions with different Capsicum annum cultivars reveal the chemical constituents modulating root herbiovry

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Plant volatile signatures are often used as cues by herbivores to locate their preferred hosts. Here, we report on the volatile organic compounds used by the subterranean root-knot nematode (RKN) Meloidogyne incognita for host location. We compared responses of infective second stage juveniles (J2s)...

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

OpenAIRE

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

2005-01-01

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

Influence of Soil Temperature on Meloidogyne incognita Resistant and Susceptible Cotton, Gossypium hirsutum

OpenAIRE

Carter, William W.

1982-01-01

The degree of resistance by a cotton plant to Meloidogyne incognita is affected by soil temperature, particularly in moderately resistant cultivars, The total number of nematodes in the resistant and moderately resistant rools at 35 C was equal to, or greater than, the number in susceptible roots at 20, 25, or 30 C. A shift in numbers to developing and egg-bearing forms of nematodes in the susceptible cultivar as tentperature increased indicates development was affected by temperature rather ...

Mitochondrial genomes of Meloidogyne chitwoodi and M. incognita (Nematoda: Tylenchina): comparative analysis, gene order and phylogenetic relationships with other nematodes.

Science.gov (United States)

Humphreys-Pereira, Danny A; Elling, Axel A

2014-01-01

Root-knot nematodes (Meloidogyne spp.) are among the most important plant pathogens. In this study, the mitochondrial (mt) genomes of the root-knot nematodes, M. chitwoodi and M. incognita were sequenced. PCR analyses suggest that both mt genomes are circular, with an estimated size of 19.7 and 18.6-19.1kb, respectively. The mt genomes each contain a large non-coding region with tandem repeats and the control region. The mt gene arrangement of M. chitwoodi and M. incognita is unlike that of other nematodes. Sequence alignments of the two Meloidogyne mt genomes showed three translocations; two in transfer RNAs and one in cox2. Compared with other nematode mt genomes, the gene arrangement of M. chitwoodi and M. incognita was most similar to Pratylenchus vulnus. Phylogenetic analyses (Maximum Likelihood and Bayesian inference) were conducted using 78 complete mt genomes of diverse nematode species. Analyses based on nucleotides and amino acids of the 12 protein-coding mt genes showed strong support for the monophyly of class Chromadorea, but only amino acid-based analyses supported the monophyly of class Enoplea. The suborder Spirurina was not monophyletic in any of the phylogenetic analyses, contradicting the Clade III model, which groups Ascaridomorpha, Spiruromorpha and Oxyuridomorpha based on the small subunit ribosomal RNA gene. Importantly, comparisons of mt gene arrangement and tree-based methods placed Meloidogyne as sister taxa of Pratylenchus, a migratory plant endoparasitic nematode, and not with the sedentary endoparasitic Heterodera. Thus, comparative analyses of mt genomes suggest that sedentary endoparasitism in Meloidogyne and Heterodera is based on convergent evolution. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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

2005-01-01

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

Inheritance and identification of a major quantitative trait locus (QTL) that confers resistance to Meloidogyne incognita and a novel QTL for plant height in sweet sorghum

Science.gov (United States)

Southern root-knot nematodes (Meloidogyne incognita) are a pest on many economically important row crop and vegetable species and management relies on chemicals, plant resistance, and cultural practices such as crop rotation. Little is known about the inheritance of resistance to M. incognita or the...

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-06-01

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

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

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Mario Fleitas Díaz

2016-02-01

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

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

OpenAIRE

Kinloch, Robert A.

1983-01-01

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 cultivars and soybeans treated and not treated with nematicides. Yields of susceptible cultivars declined with reduced length of rotation. Nematicide treatment significantly increased yields of sus...

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

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L.S Danahap

2015-08-01

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

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

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Mônica Anghinoni Müller

2016-02-01

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

Development of virulence to Meloidogyne incognita on resistant pepper rootstocks

Energy Technology Data Exchange (ETDEWEB)

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

2014-06-01

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

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

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Donggeun Kim

2013-03-01

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

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

OpenAIRE

Adekunle O.K.; Owa T.E.

2008-01-01

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

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

Science.gov (United States)

Faske, T R

2013-03-01

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

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

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Donggeun Kim

2013-03-01

Full Text Available Root-knot nematodes (Meloidogyne spp. are among the main pathogens of greenhouse crops worldwide. Plant resistance is currently the method of choice for controlling these pests. To select resistant tomato against two 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 both root-knot nematodes: six in cherry tomato, ‘Tenten’, ‘Cadillac’, ‘Cutti’, ‘Sweet’, ‘Ppotto’, ‘Lycopin-9’, eight in globe tomato, ‘Lovely 240’, ‘Dotaerang Dia’, ‘Cupirang’, ‘Dotaerang Master’, ‘Super Dotaerang’, ‘Dotaerang Season’, ‘Miroku’, ‘Hoyong’, and three in root stock, ‘Special’, ‘Fighting’, and ‘Magnet’.

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

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Aisyafaznim Al-Idrus

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

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

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Henrique Teixeira Nunes

2010-07-01

Full Text Available 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 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 duastestemunhas 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.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. Nine treatments were evaluated: three biological agents used for seed treatment with and without post-emergence application, Aldicarb on post

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

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José Carlos Fachinello

2000-03-01

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

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

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Stéphane Bellafiore

2008-10-01

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

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

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Aline Marchese

2010-09-01

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

Effects of Essential Oils and Plant Extracts on Hatching, Migration and Mortality of Meloidogyne incognita

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S.K. Ibrahim.

2006-12-01

Full Text Available The nematicidal activity of the essential oil/pure components and plant extracts of naturally grown aromatic plant species against hatching, migration and mortality of the root knot nematode Meloidogyne incognita was investigated. The pure components carvacrol, thymol, and linalool at 1, 2 and 4 mg liter-1 concentrations were the most toxic against M. incognita second-stage juveniles (J2s followed by terpineol and menthone. Hatching was completely inhibited at low concentrations (2, 4 mg liter-1 of carvacrol, thymol, and linalool. Clove extracts (1 mg liter-1 of Allium sativum significantly reduced hatching activity to below 8%, followed by flower extracts of Foeniculum vulgare which reduced hatching to below 25%. These extracts were also toxic against J2s of M. incognita (LC50 43 followed by leaf extracts of Pinus pinea, Origanum syriacum, Mentha microcorphylla, Eucalyptus spp. and Citrus sinensis with an estimated LC50 of 44, 50, 65, 66 and 121 ppm respectively. Flower extracts of F. vulgare had the highest effect on J2 mortality in sand (86%. The highest concentration of essential oils (6% was detected in leaf extracts of Origanium syriacum. Over 30 major components were identified in all the plant extracts tested.

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

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Zhi Wei Deng

2013-04-01

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

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

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Kokalis-Burelle, Nancy; Rosskopf, Erin N

2012-06-01

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

The multi-year effects of repeatedly growing cotton with moderate resistance to Meloidogyne incognita

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Kemerait, Robert C.

2009-01-01

Meloidogyne incognita causes more damage to cotton in the US than any other pathogen. The objective of this study was to document the cumulative effect of moderate resistance on M. incognita population density, root galling, and yield suppression in the southern United States on a moderately resistant cotton genotype grown continuously for three years. Cotton genotypes were Phytogen PH98-3196 (77% suppression of M. incognita), Acala NemX (85% suppression of M. incognita), and Delta and Pine Land DP458 B/R (susceptible standard, 0% suppression). Cotton was grown in fumigated and non-fumigated plots to measure yield loss. Each genotype and nematicide combination was planted in the same place for three years at two sites to document cumulative effects. In 2006, following three years of the different genotypes, all plots at one site were planted with susceptible cotton to document residual effects of planting resistant genotypes. Root galling and nematode population densities in the soil were significantly lower, and percentage yield suppression was numerically lower, when moderately resistant cotton was grown compared to the susceptible standard in both fields in all three years. Differences between susceptible and moderately resistant genotypes are established quickly (after only one season) and then either maintained at similar levels or slightly increased in subsequent years depending on initial nematode levels. However, when susceptible cotton was grown following three years of the moderately resistant genotypes, the nematode suppression provided by moderate resistance was undetectable by the end of the first season. Moderately resistant cotton genotypes are more beneficial than previously reported and should be pursued for nematode management. Rotation of moderately resistant and susceptible cotton could be used along with nematicides to manage root-knot nematodes in a continuous cotton cropping system and reduce selection pressure on the nematodes. PMID:22661787

Efficacy of Trichoderma harzianumT22 as a biocontrol agent against root-knot nematode (Meloidogyne incognita on some soybean varieties

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T.O. Abiri

2015-01-01

Full Text Available In 2012 and 2013, a two-year field study was conducted at the University of Ilorin Teaching and Research Farm, Ilorin, the Southern Guinea Savannah Zone, Nigeria, with the aim to investigate the effect of Trichoderma harzianumT22 as a bio-control agent against a root-knot nematode (Meloidogyne incognita on some soybean varieties. The experimental field, which naturally has been known for the presence of some nematodes such as Pratylenchus, Helicitylenchus, Radopholus, Meloidogyne, Rotylenchulus, Xyphinema, was divided into two blocks, each block consisting of three plots with alleys between blocks and plots measuring 5 m and 1.5 m respectively. All treatments were replicated five times by means of a Randomized Complete Block Design. The initial soil nematode population was increased by chopping six kilograms of Meloidogyne incognita galled roots of Celosia agentea from a pure culture into all the plots. One block was treated with bio-control agent Trichoderma harzianumT22 while the second block served as a control unit. The results show that in terms of plant height, the number of branches, yield and reduction of the soil nematode population and root galls, the plants on the Trichoderma treated plots performed significantly better (P=0.05 than those in the control unit did. This therefore implies that root-knot nematodes represent a major constraint in the production of soybean while Trichoderma harzianumT22 improves the yield growth and the yield of soybean as well as better controls soil nematode populations with respect to the control trials.

Development of Efficient Screening Methods for Resistant Cucumber Plants to Meloidogyne incognita

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Sung Min Hwang

2014-06-01

Full Text Available Root-knot nematodes represent a significant problem in cucumber, causing reduction in yield and quality. To develop screening methods for resistance of cucumber to root-knot nematode Meloidogyne incognita, development of root-knot nematode of four cucumber cultivars (‘Dragonsamchuk’, ‘Asiastrike’, ‘Nebakja’ and ‘Hanelbakdadaki’ according to several conditions such as inoculum concentration, plant growth stage and transplanting period was investigated by the number of galls and egg masses produced in each seedling 45 days after inoculation. There was no difference in galls and egg masses according to the tested condition except for inoculum concentration. Reproduction of the nematode on all the tested cultivars according to inoculum concentration increased in a dose-dependent manner. On the basis of the result, the optimum conditions for root-knot development on the cultivars is to transplant period of 1 week, inoculum concentration of 5,000 eggs/plant and plant growth stage of 3-week-old in a greenhouse (25 ± 5°C. In addition, under optimum conditions, resistance of 45 commercial cucumber cultivars was evaluated. One rootstock cultivar, Union was moderately resistant to the root-knot nematode. However, no significant difference was in the resistance of the others cultivar. According to the result, we suggest an efficient screening method for new resistant cucumber to the root-knot nematode, M. incognita.

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

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Vanessa A. Antes

2012-04-01

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

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

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

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

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Siddiqui, Z.A.; Mahmood, I.

1995-01-01

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

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

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Yile Zhai

2018-02-01

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

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

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Olga A Postnikova

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

Interaction of Vesicular-arbuscular Mycorrhizal Fungi and Phosphorus with Meloidogyne incognita on Tomato.

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Cason, K M; Hussey, R S; Roncadori, R W

1983-07-01

The influence of two vesicular-arbuscular mycorrhizal fungi and phosphorus (P) nutrition on penetration, development, and reproduction by Meloidogyne incognita on Walter tomato was studied in the greenhouse. Inoculation with either Gigaspora margarita or Glomus mosseae 2 wk prior to nematode inoculation did not alter infection by M. incognita compared with nonmycorrhizal plants, regardless of soil P level (either 3 mug [low P] or 30 mug [high P] available P/g soil). At a given soil P level, nematode penetration and reproduction did not differ in mycorrhizal and nonmycorrhizal plants. However, plants grown in high P soil had greater root weights, increased nematode penetration and egg production per plant, and decreased colonization by mycorrhizal fungi, compared with plants grown in low P soil. The number of eggs per female nematode on mycorrhizal and nonmycorrhizal plants was not influenced by P treatment. Tomato plants with split root systems grown in double-compartment containers which had either low P soil in both sides or high P in one side and low P in the other, were inoculated at transplanting with G. margarita and 2 wk later one-half of the split root system of each plant was inoculated with M. incognita larvae. Although the mycoorhizal fungus increased the inorganic P content of the root to a level comparable to that in plants grown in high P soil, nematode penetration and reproduction were not altered. In a third series of experiments, the rate of nematode development was not influenced by either the presence of G. margarita or high soil P, compared with control plants grown in low P soil. These data indicate that supplemental P (30 mu/g soil) alters root-knot nematode infection of tomato more than G. mosseae and G. margarita.

Biocontrol potential of Pasteuria penetrans, Pochonia chlamydosporia, Paecilomyces lilacinus and Trichoderma harzianum against Meloidogyne incognita in

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Tariq MUKHTAR

2013-05-01

Full Text Available The root-knot nematode, Meloidogyne incognita, is a sedentary endoparasitic plant pathogen with a very wide host range, which causes annual crop losses amounting to millions of dollars. The small number of available nematicides and restrictions on the use of non-fumigant nematicides due to high toxicity to humans and non-target organisms hinder effective nematode control. A possible alternative to chemical nematicides is the use of biological control agents for the management of this nematode. In the present study, the efficacy of four biocontrol agents was tested against M. incognita at different doses. The biocontrol agents Pasteuria penetrans, Pochonia chlamydosporia, Paecilomyces lilacinus and Trichoderma harzianum were mass produced and mixed with the formalin sterilized soil at the rates of 2 × 103, 4 × 103, 6 × 103, 8 × 103, and 1 × 104 endospores/chlamydospores/cfu per g of soil. Okra seeds (cv. Sabz Pari were sown in pots of soil amended with the different agents, and 10 d after emergence, the plants were inoculated with 2000 freshly hatched second stage juveniles of M. incognita. Data on plant growth parameters and nematode infestations were recorded 7 weeks after inoculation. The antagonists varied significantly in enhancing various growth parameters and reducing nematode infestations in a dose-responsive manner. Both P. penetrans and P. lilacinus were equally effective and caused maximum reductions in number of galls, egg masses, nematode fecundity and build up as compared with T. harzianum and P. chlamydosporia. Reductions in these parameters at the concentration of 8 × 103 were statistically similar with those caused at the concentration of 1 × 104 chlamydospores/ endospores/cfu. Our results indicate that application of antagonists can suppress galling and reproduction of M. incognita resulting in enhancement of plant growth.

Vertical Distribution of Pasteuria penetrans Parasitizing Meloidogyne incognita on Pittosporum tobira in Florida.

Science.gov (United States)

Baidoo, Richard; Mengistu, Tesfamariam Mekete; Brito, Janete A; McSorley, Robert; Stamps, Robert H; Crow, William T

2017-09-01

Pasteuria penetrans is considered as the primary agent responsible for soil suppressiveness to root-knot nematodes widely distributed in many agricultural fields. A preliminary survey on a Pittosporum tobira field where the grower had experienced a continuous decline in productivity caused by Meloidogyne incognita showed that the nematode was infected with Pasteuria penetrans . For effective control of the nematode, the bacterium and the host must coexist in the same root zone. The vertical distribution of Pasteuria penetrans and its relationship with the nematode host in the soil was investigated to identify (i) the vertical distribution of P. penetrans endospores in an irrigated P. tobira field and (ii) the relationship among P. penetrans endospore density, M. incognita J2 population density, and host plant root distribution over time. Soil bioassays revealed that endospore density was greater in the upper 18 cm of the top soil compared with the underlying depths. A correlation analysis showed that the endospore density was positively related to the J2 population density and host plant root distribution. Thus, the vertical distribution of P. penetrans was largely dependent on its nematode host which in turn was determined by the distribution of the host plant roots. The Pasteuria was predominant mostly in the upper layers of the soil where their nematode host and the plant host roots are abundant, a factor which may be a critical consideration when using P. penetrans as a nematode biological control agent.

Sensitive PCR Detection of Meloidogyne arenaria, M. incognita, and M. javanica Extracted from Soil

Science.gov (United States)

Qiu, Jinya Jack; Westerdahl, Becky B.; Anderson, Cindy; Williamson, Valerie M.

2006-01-01

We have developed a simple PCR assay protocol for detection of the root-knot nematode (RKN) species Meloidogyne arenaria, M. incognita, and M. javanica extracted from soil. Nematodes are extracted from soil using Baermann funnels and centrifugal flotation. The nematode-containing fraction is then digested with proteinase K, and a PCR assay is carried out with primers specific for this group of RKN and with universal primers spanning the ITS of rRNA genes. The presence of RKN J2 can be detected among large numbers of other plant-parasitic and free-living nematodes. The procedure was tested with several soil types and crops from different locations and was found to be sensitive and accurate. Analysis of unknowns and spiked soil samples indicated that detection sensitivity was the same as or higher than by microscopic examination. PMID:19259460

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Effect of Mowing Cotton Stalks and Preventing Plant Re-Growth on Post-Harvest Reproduction of Meloidogyne incognita

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Davis, Richard F.; Kemerait, Robert C.

2010-01-01

The southern root-knot nematode (Meloidogyne incognita) is a major parasite of cotton in the U.S., and management tactics for this nematode attempt to minimize population levels. We compared three post-harvest practices for their ability to reduce nematode population levels in the field, thereby reducing initial nematode population for the next year's crop. The three practices tested were: 1) chemical defoliation before harvest plus cutting cotton stalks after harvest, 2) chemical defoliation plus applying a herbicide to kill plants prior to cutting the stalks, and 3) chemical defoliation without cutting stalks. Experiments were conducted in both the greenhouse and in the field. The greenhouse experiments demonstrated that M. incognita reproduction (measured as egg counts and root gall rating indices) was significantly greater when stalks were not cut. Cutting stalks plus applying herbicide to kill cotton roots did not significantly reduce nematode reproduction compared to cutting stalks alone. In field experiments, cutting stalks reduced egg populations and root galling compared to defoliation without stalk cutting. In a greenhouse bioassay which used soil from the field plots, plants grown in soil from the defoliation only treatment had greater root gall ratings and egg counts than in the stalk cutting plus herbicide treatment. Therefore, we conclude that cutting cotton stalks immediately after harvest effectively reduces M. incognita reproduction, and may lead to a lower initial population density of this nematode in the following year. PMID:22736845

Efecto del follaje de Tagetes minuta sobre la nodulación radicular de Meloidogyne incognita en Capsicum annuum, en invernadero

OpenAIRE

Murga-Gutiérrez, Santos Nélida; Alvarado-Ibáñez, Juan Carlos; Vera-Obando, Nora Yessenia

2012-01-01

Se investigó el efecto del follaje del "huacatay" Tagetes minuta sobre la nodulación radicular producida por el nematodo Meloidogyne incognita que parasita el "pimiento páprika" Capsicum annuum cultivado en invernadero, con la finalidad de obtener una alternativa de control de este nematodo. Se utilizaron tres grupos experimentales y un testigo, con 12 macetas cada uno, las cuales contenían suelo y arena estériles (1:1). A este substrato se adicionó el follaje de T. minuta al 20, 35 y 50% (v/...

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

DEFF Research Database (Denmark)

Shukla, Neha; Yadav, Rachita; Kaur, Pritam

2017-01-01

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

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

DEFF Research Database (Denmark)

Shukla, Neha; Yadav, Rachita; Kaur, Pritam

2018-01-01

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

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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Isabel Cristina Madeira Ferreira

2013-03-01

Full Text Available Estudou-se, in vitro e in vivo a atividade nematicida dos extratos aquosos de vedélia (Sphagneticola trilobata, erva-de-touro (Tridax procumbens, cravo-de-defunto (Tagetes patula, girassol mexicano (Tithonia diversifolia, botão de ouro (Unxia suffruticosa e zínia (Zinnia peruviana, sobre Meloidogyne incognita. Os extratos foram preparados na proporção de 1,0g do material seco e triturado para 10mL de água destilada e armazenados por 24h, sendo seguidamente utilizados nos experimentos. Nos testes in vitro, foram depositados 4,0mL do extrato bruto e 2,0mL de uma suspensão aquosa contendo 200 ovos do nematóide em placas de Petri de 5cm de diâmetro e, quinze dias após, procedeu-se a contagem do número de juvenis eclodidos e dos ovos remanescentes para o cálculo das porcentagens de eclosão. Nos testes in vivo, os extratos foram aplicados, separadamente, via pulverização foliar, tratamento de raiz e vertido no solo, semanalmente durante 60 dias. Como testemunha utilizou-se apenas água nos dois experimentos. No ensaio in vitro observou-se que todos os extratos foram eficientes na redução da eclosão de juvenis de M. incognita quando comparados à testemunha, as porcentagens de redução foram 89,96%, 91,13%, 92,48%, 92,72%, 93,2% e 97,48% para erva-de-touro, cravo-de-defunto, girassol mexicano, vedélia, botão de ouro e zínia, respectivamente, e no ensaio in vivo, que os tratamentos não exerceram nenhum efeito sobre o peso do sistema radicular dos tomateiros, no entanto, observou-se que os resultados diferiram entre as espécies utilizadas e a forma de aplicação do extrato na avaliação do peso fresco da parte aérea das plantas. Quanto ao fator de reprodução, observou-se que nenhum dos extratos apresentou diferença estatística em relação à testemunha, no entanto, quando se compara as diferentes formas de aplicação dos mesmos, observa-se que houve diferença estatística quando os extratos de erva de touro e girassol

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

Science.gov (United States)

McSorley, R; Dickson, D W

1995-12-01

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 (crop planted in 1994, but increased by the end of the eggplant crop. The rotation crops planted during 1993 had little effect on yield of eggplant in 1994. Eggplant yield was inversely correlated with preplant densities (Pi) of Belonolaimus longicaudatus (r = -0.282; P crop cultivars were lower (P crops intended for suppression of individual Meloidogyne spp. be evaluated for their response to other nematode pests as well.

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

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M.E El-Hadad

2011-03-01

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

Interaction of Endomycorrhizal Fungi, Superphosphate, and Meloidogyne incognita on Cotton in Microplot and Field Studies.

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Smith, G S; Roncadori, R W; Hussey, R S

1986-04-01

Microplot and field experiments were conducted to determine the effects of two vesicular-arbuscular mycorrhizal (VAM) fungi, Glomus intraradices (Gi) and Gigaspora margarita (Gm), and dicalcium phosphate (P) on Meloidogyne incognita (Mi) reproduction and seed cotton yield of the Mi-susceptible cotton cultivar, Stoneville 213. In 1983 population densities of Mi juveniles were significantly lower 60 and 90 days after planting in microplots receiving Gi. Mycorrhizal fungi reduced the severity of yield losses to Mi, whereas P fertilization increased yield losses to Mi. In 1984 microplot yields were reduced linearly as nematode inoculum densities increased in treatments of Mi alone, Gm, or P, but the response was curvilinear with Gi. Yield suppressions in the 1984 field experiment occurred only in plots infested with Mi alone. In the 1984 microplots, numbers of Mi juveniles penetrating seedling roots increased Iinearly with increasing nematode inoculum densities and was favored when mycorrhizal fungi or superphosphate were added. Juvenile penetration of roots was negatively correlated with yields in all treatments (r = -0.54 to -0.81) except Gm and with number of bolls in Mi alone (r = -0.85) and P (r = -0.81) treatments. Mycorrhizal fungi can increase host tolerance to M. incognita in field conditions and may function as important biological control agents in soils infested with high population densities of efficient VAM species.

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

African Journals Online (AJOL)

Integrated management of root-knot nematode (Meloidogyne incognita) for tomato production and productivity. Bayuh Belay1* ... important food and cash crop of the farmers and is ...... some part of the research budget without any reservation.

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

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

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

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Ja Yeong Jang

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

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

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

2008-06-01

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

Solubilization of insoluble zinc compounds by Gluconacetobacter diazotrophicus and the detrimental action of zinc ion (Zn2+) and zinc chelates on root knot nematode Meloidogyne incognita.

Science.gov (United States)

Saravanan, V S; Kalaiarasan, P; Madhaiyan, M; Thangaraju, M

2007-03-01

To examine the zinc (Zn) solubilization potential and nematicidal properties of Gluconacetobacter diazotrophicus. Atomic Absorption Spectrophotometer, Differential Pulse Polarography and Gas Chromatography Coupled Mass Spectrometry were used to estimate the total Zn and Zn(2+) ions and identify the organic acids present in the culture supernatants. The effect of culture filtrate of Zn-amended G. diazotrophicus PAl5 on Meloidogyne incognita in tomato was examined under gnotobiotic conditions. Gluconacetobacter diazotrophicus PAl5 effectively solubilized the Zn compounds tested and 5-ketogluconic acid was identified as the major organic acid aiding the solubilization of zinc oxide. The presence of Zn compounds in the culture filtrates of G. diazotrophicus enhanced the mortality and reduced the root penetration of M. incognita under in vitro conditions. 5-ketogluconic acid produced by G. diazotrophicus mediated the solubilization process and the available Zn(2+) ions enhanced the nematicidal activity of G. diazotrophicus against M. incognita. Zn solubilization and enhanced nematicidal activity of Zn-amended G. diazotrophicus provides the possibility of exploiting it as a plant growth promoting bacteria.

Bakteri Endofit Asal Berbagai Akar Tanaman sebagai Agens Pengendali Nematoda Puru Akar Meloidogyne incognita pada Tomat

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Pradana Pandu Ankardiansyah

2016-08-01

Full Text Available Infection caused by root knot nematode (RKN Meloidogyne incognita may cause yield losses. Little is known regarding the effectiveness of endophytic bacterial group as biocontrol agents of RKN. This research was aimed to obtain endophytic bacteria group from 16 species of plants, which effectively controlled the RKN. Isolation of endophytic bacteria group was conducted using NA 20%, NA 50%, TSA 20%, TSA 50%, and King’s B medium. All of the bacteria groups giving negative result in hypersensitive and haemolytic tests, was further examined for their ability to produce protease, chitinase, and cyanide acid. The same endophytic bacteria groups were also tested for their potential to control juvenile 2 of M. incognita on tomatoes by seed treatment and soil drenching. Agronomical and pathological traits were observed 40 days after nematodes infestation. Eighty endophytic bacteria groups were successfully isolated and 17 of them were considered potential. Physiological test showed that 16 groups of endophytic bacteria can produce protease enzyme, 12 groups can produce chitinase enzyme, and 5 groups can produce cyanide acid. Specific endophytic bacteria group, i.e. TmtN5 from roots of tomato plant, is the most effective isolate for suppressing root damage and population of RKN. This group was effective as biocontrol agents of RKN because it produceds chitinase, protease, and cyanide acid. This research provided a new information regarding the potential use of endophytic bacteria group as a biocontrol agent of RKN.

Meloidogyne partityla on Pecan Isozyme Phenotypes and Other Host.

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

1996-12-01

Meloidogyne sp. from five pecan (Carya illinoensis) orchards in Texas were distinctive in host range and iszoyme profiles from common species of Meloidogyne but were morphologically congruent with Meloidogyne partityla Kleynhans, a species previously known only in South Africa. In addition to pecan, species of walnut (Juglans hindsii and J. regia) and hickory (C. ovata) also were hosts. No reproduction was observed on 15 other plant species from nine families, including several common hosts of other Meloidogyne spp. Three esterase phenotypes and two malate dehydrogenase phenotypes of M. partityla were identified by polyacrylamide gel electrophoresis. Each of these isozyme phenotypes was distinct from those of the more common species M. arenaria, M. hapla, M. incognita, and M. javanica.

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

Science.gov (United States)

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

2013-05-22

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.

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

Science.gov (United States)

Dwi Sri Hastuti, Liana; Faull, Jane

2018-03-01

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

Meloidogyne partityla on Pecan Isozyme Phenotypes and Other Host

Science.gov (United States)

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

1996-01-01

Meloidogyne sp. from five pecan (Carya illinoensis) orchards in Texas were distinctive in host range and iszoyme profiles from common species of Meloidogyne but were morphologically congruent with Meloidogyne partityla Kleynhans, a species previously known only in South Africa. In addition to pecan, species of walnut (Juglans hindsii and J. regia) and hickory (C. ovata) also were hosts. No reproduction was observed on 15 other plant species from nine families, including several common hosts of other Meloidogyne spp. Three esterase phenotypes and two malate dehydrogenase phenotypes of M. partityla were identified by polyacrylamide gel electrophoresis. Each of these isozyme phenotypes was distinct from those of the more common species M. arenaria, M. hapla, M. incognita, and M. javanica. PMID:19277175

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

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Hari C. Meher

2011-10-01

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

IDENTIFICACIÓN MORFOLÓGICA, MORFOMÉTRICA Y MOLECULAR DE Meloidogyne incognita EN HIGUERA (Ficus carica L. EN COSTA RICA

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Walter Peraza-Padilla

2013-01-01

Full Text Available El objetivo de este estudio fue identificar la especie de Meloidogyne asociada a dos plantaciones de higuera en Costa Rica. En marzo de 2012, en el distrito de Pacayas, provincia de Cartago, se detectaron agallas en los sistemas radicales de plantas de higuera (Ficus carica L. de dos fincas. De las raíces agalladas se extrajeron hembras, masas de huevos y juveniles (J2 de Meloidogyne sp. Se examinaron los patrones perineales de las hembras y los segundos estadios infectivos se analizaron morfológica y molecularmente mediante PCR-RFLP. Se amplificó la región intergénica (IGS del genoma mitocondrial, delimitada por el gen de la subunidad II de la citocromo oxidasa (COII y el gen ribosomal 16S. La población de nematodos se identificó como M. incognita. El tamaño de los productos de PCR generados con los imprimadores C2F3 y 1108 fue de 1,7 kb. Al tratar los productos de PCR con enzimas de restricción, se generaron cuatro fragmentos de 850, 450, 250 y 150 pb con la enzima AluI y dos fragmentos de 1300 y 400 pb con la enzima HinfI.

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

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

2013-08-01

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

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

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Gamal El-Din Abd El Kader Y

2011-05-01

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

Natural suppression of Meloidogyne incognita by Pasteuria penetrans in cotton

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The endospore-forming bacterium Pasteuria penetrans is an obligate parasite of root-knot nematodes (Meloidogyne spp.). This bacterium is commonly found in agricultural soils and has been associated with suppression of Meloidogyne spp. In a field site naturally infested with both P. penetrans and M...

Potential Antioxidant Anthraquinones Isolated from Rheum emodi Showing Nematicidal Activity against Meloidogyne incognita

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Brijesh Tripathi

2014-01-01

Full Text Available Antioxidant and nematicidal properties were evaluated for R. emodi extractives which are extracted by standardizing and adopting accelerated solvent extraction (ASE method along with traditional Soxhlet extraction. The extracted material was separated using flash chromatography and the separation conditions and solvents were standardized for the extracted plant constituents. The purity was detected by using analytical reverse phase high pressure liquid chromatography (HPLC. LC-MS/MS detection in the direct infusion mode of the isolated, purified products afforded four anthraquinones, characterized by their infrared spectra (IR and 1H spectra as chrysophanol, physcion, emodin, and aloe-emodin. Five antraquinone glucoside derivatives and piceatannol-3-O-β-d-glucopyranoside have also been detected from the extracted product. During in vitro evaluation the antioxidant potential of methanolic crude extract (CE1 was the highest, followed by ethyl acetate crude extract (CE2 and chloroform extract (CE3 in DPPH radical scavenging activity. The CE1 also demonstrated outstanding nematicidal activity as compared with other extracts, pure anthraquinones, and even positive control azadirachtin. The study conclusively demonstrated the antioxidant potential of R. emodi extracts and also its ability in extenuating the Meloidogyne incognita (root-knot nematode. The bioassay results can be extrapolated to actual field condition and clinical studies.

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

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Phani, Victor; Shivakumara, Tagginahalli N; Davies, Keith G; Rao, Uma

2017-01-01

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

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

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Victor Phani

2017-11-01

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

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

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Fernando da Silva Rocha

2009-02-01

Full Text Available Neste trabalho, objetivou-se estudar o efeito do período de armazenamento no teor de lipídios de juvenis do segundo estádio (J2 de M. incognita com endósporos de P. penetrans na infectividade e reprodução em tomateiro. Suspensões de M. incognita contendo ou não endósporos de P. penetrans aderidos à cutícula foram armazenadas por 0, 3, 6, 9 e 12 dias, a 28ºC. Após cada período de estocagem, determinou-se a concentração de lipídios neutros corporais por meio da análise de imagem dos J2 coloridos com o corante "Oil Red O". Em seguida, 1.000 J2 foram inoculados em mudas de tomateiros. Após 28 dias, avaliou-se o número de fêmeas parasitadas, número de endósporos/fêmea, número de galhas, massas de ovos e de ovos/g de raiz. O teor de lipídio dos J2 reduziu-se com o aumento do período de estocagem. Porém, maiores perdas ocorreram nos J2 sem endósporos de P. penetrans. A proporção entre as perdas dos J2 com e sem P. penetrans foi pequena e decrescente com o período de estocagem. Entretanto, a desproporção foi grande entre 3 e 6 dias de armazenamento dos J2 com e sem P. penetrans com relação aos parâmetros reprodução e número de galhas, indicando consumo de fontes alternativas ao lipí dio neutro de energia p elo J2 parasitado. Mas o período de armazenamento sempre reduziu a reprodução e número de galhas formadas em tomateiros por J2 com e sem P. penetrans. A perda dessas fontes de energia, ao que tudo indica, leva muitos J2 a morrer antes de chegar ao estádio adulto, pois o número de fêmeas parasitadas reduz-se com o armazenamento, além de propiciar menor produção de endósporos por fêmea. O J2 parasitado por P. penetrans necessita encontrar rapidamente a raiz e não permanecer no solo por mais de 6 dias antes de parasitar a planta.This work aimed to study the effect of storage period on lipid content of second stage juveniles (J2 of M. incognita with endospores of P. penetrans on infectivity and

Non-nematode-derived double-stranded RNAs induce profound phenotypic changes in Meloidogyne incognita and Globodera pallida infective juveniles.

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Dalzell, Johnathan J; McMaster, Steven; Johnston, Michael J; Kerr, Rachel; Fleming, Colin C; Maule, Aaron G

2009-11-01

Nine non-nematode-derived double-stranded RNAs (dsRNAs), designed for use as controls in RNA interference (RNAi) screens of neuropeptide targets, were found to induce aberrant phenotypes and an unexpected inhibitory effect on motility of root knot nematode Meloidogyne incognita J2s following 24h soaks in 0.1 mg/ml dsRNA; a simple soaking procedure which we have found to elicit profound knockdown of neuronal targets in Globodera pallida J2s. We have established that this inhibitory phenomenon is both time- and concentration-dependent, as shorter 4h soaks in 0.1 mg/ml dsRNA had no negative impact on M. incognita J2 stage worms, yet a 10-fold increase in concentration to 1 mg/ml for the same 4h time period had an even greater qualitative and quantitative impact on worm phenotype and motility. Further, a 10-fold increase of J2s soaked in 0.1 mg/ml dsRNA did not significantly alter the observed phenotypic aberration, which suggests that dsRNA uptake of the soaked J2s is not saturated under these conditions. This phenomenon was not initially observed in potato cyst nematode G. pallida J2s, which displayed no aberrant phenotype, or diminution of migratory activity in response to the same 0.1 mg/ml dsRNA 24h soaks. However, a 10-fold increase in dsRNA to 1mg/ml was found to elicit comparable irregularity of phenotype and inhibition of motility in G. pallida, to that initially observed in M. incognita following a 24h soak in 0.1 mg/ml dsRNA. Again, a 10-fold increase in the number of G. pallida J2s soaked in the same volume of 1 mg/ml dsRNA preparation did not significantly affect the observed phenotypic deviation. We do not observe any global impact on transcript abundance in either M. incognita or G. pallida J2s following 0.1 mg/ml dsRNA soaks, as revealed by reverse transcriptase-PCR and quantitative PCR data. This study aims to raise awareness of a phenomenon which we observe consistently and which we believe signifies a more expansive deficiency in our knowledge and

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

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Leida Castro

2011-01-01

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

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

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Silvia Renata S Wilcken

2010-03-01

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

KETAHANAN BEBERAPA VARIETAS UNGGUL KEDELAI TERHADAP NEMATODA PURU AKAR (Meloidogyne incognita

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Wayan Sukanaya

2001-07-01

Full Text Available The aims of this experiment are to find the varieties of soybean which are resistant against root-knot nematode (M. incognita and to determine its attractancy toward the roots of resistant and susceptible soybean varieties. The experiment was divided into two parts, both parts using Completely Randomized Design. The first part was designed to determine the resistance and the second one to determine attractancy. The experiments were conducted in a green house and Plant Pest and Disease Laboratory, Faculty of Agriculture, Udayana University for 5 months. Of the 23 varieties of soybean tested against M. incognita showed that two varieties (Petek and Rinjani were moderately resistant, 11 varieties were moderately susceptible and 10 varieties were found to be susceptible. However, none of variety was resistant. While on attractancy of root test of moderately resistant and susceptible variety it was found that M. incognita was more attracted to root of susceptible variety (Ringgit than to moderately resistant variety (Petek. Key words: soybean, resistance, root-knot nematode

Impact of direct and indirect application of rising furfural concentrations on viability, infectivity and reproduction of the root-knot nematode, Meloidogyne incognita in Pisum sativum.

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Abdelnabby, Hazem; Wang, Yunhe; Xiao, Xueqiong; Wang, Gaofeng; Yang, Fan; Xiao, Yannong

2016-07-01

The gradual withdraw of several broadly used nematicides from market has enhanced the need to develop sustainable and eco-friendly alternatives with nematicidal properties. Furfural is one of the promising alternatives to fill this need. Baseline information about the impact of furfural on egg hatch, penetration potential and ultrastructure of nematode is lacking. In this study, the reagent-grade (purity ≥ 99.0%) of furfural was applied against Meloidogyne incognita. In vitro tests showed gradual reduction in either the rate of egg hatch or second stage juvenile (J2) viability of M. incognita when immersed in concentrations ranging from 0 to 10.0 μl/ml furfural. The mean EC50 for J2 and egg hatch was 0.37 and 0.27 μl/ml furfural, respectively. Furfural, even at low concentrations, resulted in a considerable suppression in egg hatch. Hatch was 0.2 ml/kg soil. No adverse effect was detected on plants or free-living nematodes as a result of furfural application. Liquid furfural proved to have superior juvenile-suppressive effect whereas its vapor has such superiority against eggs. Scanning electron microscope (SEM) study showed irregular appearance of the body surface accompanied with some cuticle disfigurement of furfural-treated juveniles. These results indicated that furfural can adversely affect egg hatch, juvenile viability, penetration potential and ultrastructure of M. incognita. Furfural may therefore be of a considerable potential as an appropriate alternative for class I nematicides. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of resistance to Neoleucinodes elegantalis Guennée and Meloidogyne incognita in an F1 hybrid of Solanum quitoense Lam.

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Manuel Francisco Polanco Puerta

2018-05-01

Full Text Available The aim of this study was to cross lulo plants of cv. La Selva to obtain a hybrid with tolerance to the fruit borer Neoleucinodes elegantalis Guenée (Lepidoptera: Crambidae and to the nematode Meloidogyne incognita (Kofoid & White (Nematoda: Heteroderidae, to obtain better-adapted plants to the conditions of the Colombian coffee-growing region and with bigger and non-dehiscent fruits. La Selva cultivar is a hybrid developed from the interspecific backcross of Solanum quitoense Lam. × Solanum hirtum Vahl with plants of lulo cv. Castilla Larga Vida. The experiment was conducted in the municipality of Dosquebradas, Risaralda, Colombia, located at 1,465 m a.s.l. F1 plants were obtained from reciprocal crossings. When inoculated with the nematode M. incognita, plants showed susceptibility in their seedling stage; however, when we carried out the evaluation six months after transplantation under field conditions, nematode infestation was less than 1%, which likely indicates the tolerance of these materials to the nematode. When assessing the resistance of the hybrid to the attack of N. elegantalis, we found that the evaluated materials were resistant to this insect. The resulting hybrids showed good agronomic characteristics, such as a good morphological structure and vigor, high productivity, good solar exposure adaptation, large fruits (5.6 cm average diameter similar to those of cv. Castilla, with yellow peel, green pulp and non-dehiscent fruits with pleasant aroma and flavor. As an undesirable characteristic plants had thorns on leaves and stems.

Host-Induced Silencing of Two Pharyngeal Gland Genes Conferred Transcriptional Alteration of Cell Wall-Modifying Enzymes of Meloidogyne incognita vis-à-vis Perturbed Nematode Infectivity in Eggplant.

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Shivakumara, Tagginahalli N; Chaudhary, Sonam; Kamaraju, Divya; Dutta, Tushar K; Papolu, Pradeep K; Banakar, Prakash; Sreevathsa, Rohini; Singh, Bhupinder; Manjaiah, K M; Rao, Uma

2017-01-01

The complex parasitic strategy of Meloidogyne incognita appears to involve simultaneous expression of its pharyngeal gland-specific effector genes in order to colonize the host plants. Research reports related to effector crosstalk in phytonematodes for successful parasitism of the host tissue is yet underexplored. In view of this, we have used in planta effector screening approach to understand the possible interaction of pioneer genes ( msp-18 and msp-20 , putatively involved in late and early stage of M. incognita parasitism, respectively) with other unrelated effectors such as cell-wall modifying enzymes (CWMEs) in M. incognita . Host-induced gene silencing (HIGS) strategy was used to generate the transgenic eggplants expressing msp-18 and msp-20 , independently. Putative transformants were characterized via qRT-PCR and Southern hybridization assay. SiRNAs specific to msp-18 and msp - 20 were also detected in the transformants via Northern hybridization assay. Transgenic expression of the RNAi constructs of msp-18 and msp-20 genes resulted in 43.64-69.68% and 41.74-67.30% reduction in M. incognita multiplication encompassing 6 and 10 events, respectively. Additionally, transcriptional oscillation of CWMEs documented in the penetrating and developing nematodes suggested the possible interaction among CWMEs and pioneer genes. The rapid assimilation of plant-derived carbon by invading nematodes was also demonstrated using 14 C isotope probing approach. Our data suggests that HIGS of msp-18 and msp-20 , improves nematode resistance in eggplant by affecting the steady-state transcription level of CWME genes in invading nematodes, and safeguard the plant against nematode invasion at very early stage because nematodes may become the recipient of bioactive RNA species during the process of penetration into the plant root.

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

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Kumari, N Swarna; Sivakumar, C V

2005-01-01

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.

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.

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

2009-02-01

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.

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

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S. A. Abolusoro

2016-01-01

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

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

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Qaiser Jamal

2017-10-01

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

Evaluación de la infestación de cinco especies de solanáceas al parasitismo del nemátodo del nudo de la raíz Meloidogyne incognita y el contenido de alcaloides en frutos de tomate de árbol y naranjilla injertados en estas especies

OpenAIRE

Navarrete Bastidas, Ximena Elianet

2017-01-01

Existe una alta incidencia del nemátodo Meloidogyne incognita en Solanáceas de importancia económica. Este patógeno ocasiona daños en la planta, llegando a producir hasta la muerte y ocasionando pérdidas para el agricultor. En la presente investigación, se evaluó la respuesta de infestación de cinco especies de Solanáceas silvestres (Solanum auriculatum, S.hirtum, S.hispidum, S.arboreum y Nicotiana glauca) al parasitismo de M. incognita. Se utilizó un diseño de bloques completamente al azar c...

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

Science.gov (United States)

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

2016-02-01

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

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

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Camilla Martins de Oliveira

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

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

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Gufran Ahmad

2016-09-01

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

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

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

2016-03-01

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

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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Hércules Diniz Campos

2007-09-01

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.

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

NARCIS (Netherlands)

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

2011-01-01

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

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

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Jose T. A. Oliveira

2014-11-01

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

A High-Throughput Molecular Pipeline Reveals the Diversity in Prevalence and Abundance of Pratylenchus and Meloidogyne Species in Coffee Plantations.

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Bell, Christopher A; Atkinson, Howard J; Andrade, Alan C; Nguyen, Hoa X; Swibawa, I Gede; Lilley, Catherine J; McCarthy, James; Urwin, P E

2018-05-01

Coffee yields are adversely affected by plant-parasitic nematodes and the pathogens are largely underreported because a simple and reliable identification method is not available. We describe a polymerase chain reaction-based approach to rapidly detect and quantify the major Pratylenchus and Meloidogyne nematode species that are capable of parasitizing coffee. The procedure was applied to soil samples obtained from a number of coffee farms in Brazil, Vietnam, and Indonesia to assess the prevalence of these species associated both with coffee (Coffea arabica and C. canephora) and its intercropped species Musa acuminata (banana) and Piper nigrum (black pepper). Pratylenchus coffeae and P. brachyurus were associated with coffee in all three countries but there were distinct profiles of Meloidogyne spp. Meloidogyne incognita, M. exigua, and M. paranaensis were identified in samples from Brazil and M. incognita and M. hapla were detected around the roots of coffee in Vietnam. No Meloidogyne spp. were detected in samples from Indonesia. There was a high abundance of Meloidogyne spp. in soil samples in which Pratylenchus spp. were low or not detected, suggesting that the success of one genus may deter another. Meloidogyne spp. in Vietnam and Pratylenchus spp. in Indonesia were more numerous around intercropped plants than in association with coffee. The data suggest a widespread but differential nematode problem associated with coffee production across the regions studied. The issue is compounded by the current choice of intercrops that support large nematode populations. Wider application of the approach would elucidate the true global scale of the nematode problem and the cost to coffee production. [Formula: see text] Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

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).

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

2008-06-01

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.

The Infection of Cucumber (Cucumis sativus L. Roots by Meloidogyne incognita Alters the Expression of Actin-Depolymerizing Factor (ADF Genes, Particularly in Association with Giant Cell Formation

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Bin Liu

2016-09-01

Full Text Available Cucumber (Cucumis sativus L. is threatened by substantial yield losses due to the south root-knot nematode (Meloidogyne incognita. However, understanding of the molecular mechanisms underlying the process of nematode infection is still limited. In this study, we found that M. incognita infection affected the structure of cells in cucumber roots and treatment of the cytoskeleton inhibitor (cytochalasin D reduced root-knot nematode (RKN parasitism. It is known that Actin-Depolymerizing Factor (ADF affects cell structure, as well as the organization of the cytoskeleton. To address the hypothesis that nematode-induced abnormal cell structures and cytoskeletal rearrangements might be mediated by the ADF genes, we identified and characterized eight cucumber ADF (CsADF genes. Phylogenetic analysis showed that the cucumber ADF gene family is grouped into four ancient subclasses. Expression analysis revealed that CsADF1, CsADF2-1, CsADF2-2, CsADF2-3 (Subclass I and CsADF6 (Subclass III have higher transcript levels than CsADF7-1, CsADF7-2 (Subclass II genes and CsADF5 (Subclass IV in roots. Members of subclass I genes (CsADF1, CsADF2-1, CsADF2-2 and CsADF2-3, with the exception of CsADF2-1, exhibited a induction of expression in roots 14 days after their inoculation (DAI with nematodes. However, the expression of subclass II genes (CsADF7-1 and CsADF7-2 showed no significant change after inoculation. The transcript levels of CsADF6 (Subclass III showed a specific induction at 21 DAI, while CsADF5 (Subclass IV was weakly expressed in roots, but was strongly up-regulated as early as 7 DAI. In addition, treatment of roots with cytochalasin D caused an approximately two-fold down-regulation of the CsADF genes in the treated plants. These results suggest that CsADF gene mediated actin dynamics are associated with structural changes in roots as a consequence of M. incognita infection.

Reação de clones de bananeira(Musa spp. ao nematóide Meloidogyne incognita (Kofoid & White, 1919 Chitwood, 1949, Raça 2

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Vilas Boas Lenisa Cezar

2002-01-01

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.

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

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Marissônia de Araujo Noronha

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

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

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Cristian Gelpud Chaves

2011-01-01

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

Expression and evolutionary analyses of three acetylcholinesterase genes (Mi-ace-1, Mi-ace-2, Mi-ace-3) in the root-knot nematode Meloidogyne incognita.

Science.gov (United States)

Cui, Ruqiang; Zhang, Lei; Chen, Yuyan; Huang, Wenkun; Fan, Chengming; Wu, Qingsong; Peng, Deliang; da Silva, Washington; Sun, Xiaotang

2017-05-01

The full cDNA of Mi-ace-3 encoding an acetylcholinesterase (AChE) in Meloidogyne incognita was cloned and characterized. Mi-ace-3 had an open reading frame of 1875 bp encoding 624 amino acid residues. Key residues essential to AChE structure and function were conserved. The deduced Mi-ACE-3 protein sequence had 72% amino acid similarity with that of Ditylenchus destructor Dd-AChE-3. Phylogenetic analyses using 41 AChEs from 24 species showed that Mi-ACE-3 formed a cluster with 4 other nematode AChEs. Our results revealed that the Mi-ace-3 cloned in this study, which is orthologous to Caenorhabditis elegans AChE, belongs to the nematode ACE-3/4 subgroup. There was a significant reduction in the number of galls in transgenic tobacco roots when Mi-ace-1, Mi-ace-2, and Mi-ace-3 were knocked down simultaneously, whereas little or no effect were observed when only one or two of these genes were knocked down. This is an indication that the functions of these three genes are redundant. Copyright © 2017. Published by Elsevier Inc.

Influence of crop production practices on Pasteuria penetrans and suppression of Meloidogyne incognita

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Pasteuria penetrans is a parasite of root-knot nematodes (Meloidogyne spp.). Infected nematodes are not killed by the bacterium, but instead of producing eggs, females produce millions of infectious endospores. In addition to sterilizing females, P. penetrans can reduce nematode infection of roots...

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

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Cláudia Regina Dias-Arieira

2012-06-01

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

Nematicidal activity of furanocoumarins from parsley against Meloidogyne spp.

Science.gov (United States)

Caboni, Pierluigi; Saba, Marco; Oplos, Chrisostomos; Aissani, Nadhem; Maxia, Andrea; Menkissoglu-Spiroudi, Urania; Casu, Laura; Ntalli, Nikoletta

2015-08-01

This report describes activity against Meloidogyne spp. and chemical characterisation of the essential oil and methanol extract of Petroselinum crispum aerial parts. The study was based on the hypothesis that P. crispum could be used as an intercrop and soil amendment in tomato culture for nematode control. The methanol extract and the essential oil exhibited significant nematicidal activity against M. incognita, M. hapla and M. arenaria, the first being the most sensitive species, with EC50 /72 h values of 140 ± 15 and 795 ± 125 mg L(-1) for the extract and oil respectively. The most abundant furanocoumarin compounds in the methanolic extract were xanthotoxin, psoralen, bergapten and oxypeucedanin; levels ranged from 1.77 to 46.04 mg kg(-1) wet weight. The EC50 /24 h values of xanthotoxol, psoralen and xanthotoxin against M. incognita were 68 ± 33, 147 ± 88 and 200 ± 21 mg L(-1) respectively. The addition of fresh parsley paste to soil reduced the number of M. incognita females and plant galls on tomato roots; EC50 values were 24.79 and 28.07 mg g(-1) respectively. Moreover, parsley paste enhanced tomato growth in a dose-response manner. Parsley exhibits promising nematicidal activity as an organic amendment and as a source of nematotoxic furanocoumarins. © 2014 Society of Chemical Industry.

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

International Nuclear Information System (INIS)

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

2015-01-01

Nematodes species of the genus Meloidogyne associated with upland ornamental plants were identified. Ten ornamental species in a commercial nursery were sampled in San Isidro, Heredia, Costa Rica between 2011-2012. Morphometric measurements of the stylet length, the trail length, and the hyaline region of J_2s as well as perineal patterns of egg-carrying females were used for identification, Genomic DNA was extracted from single J_2s and molecular analyses were performed by amplifying the intergenic region between cytochrome oxidase subunit II of the COII and the long subunit of the ARN ribosomal genes by PCR-RFLP. Combining these methods allowed identification of five species of nematodes of the genus Meloidogyne (M. arenaria, M. hapla, M. hispanica, M. incognita and M. javanica), and new restriction enzyme patterns were reported for M. hapla and M. javanica using AluI. Additionally a preliminary report of M. hispanica was described by sequencing the 28S and 18S regions. (author) [es

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

OpenAIRE

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

1995-01-01

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

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

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

2017-02-01

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

Effects of phosphate solubilizing microorganisms and Rhizobium sp ...

African Journals Online (AJOL)

STORAGESEVER

2009-08-04

Aug 4, 2009 ... nematode Meloidogyne incognita (Kofoid and White). Chitwood and .... Meloidogyne incognita was collected from chickpea field soil identi- fied with the help perineal pattern ..... japonicum on soybean. Phytopathology, 60: ...

Nematicidal Activity of Kojic Acid Produced by Aspergillus oryzae against Meloidogyne incognita.

Science.gov (United States)

Kim, Tae Yoon; Jang, Ja Yeong; Jeon, Sun Jeong; Lee, Hye Won; Bae, Chang-Hwan; Yeo, Joo Hong; Lee, Hyang Burm; Kim, In Seon; Park, Hae Woong; Kim, Jin-Cheol

2016-08-28

The fungal strain EML-DML3PNa1 isolated from leaf of white dogwood (Cornus alba L.) showed strong nematicidal activity with juvenile mortality of 87.6% at a concentration of 20% fermentation broth filtrate at 3 days after treatment. The active fungal strain was identified as Aspergillus oryzae, which belongs to section Flavi, based on the morphological characteristics and sequence analysis of the ITS rDNA, calmodulin (CaM), and β-tubulin (BenA) genes. The strain reduced the pH value to 5.62 after 7 days of incubation. Organic acid analysis revealed the presence of citric acid (515.0 mg/kg), malic acid (506.6 mg/kg), and fumaric acid (21.7 mg/kg). The three organic acids showed moderate nematicidal activities, but the mixture of citric acid, malic acid, and fumaric acid did not exhibit the full nematicidal activity of the culture filtrate of EML- DML3PNa1. Bioassay-guided fractionation coupled with (1)H- and (13)C-NMR and EI-MS analyses led to identification of kojic acid as the major nematicidal metabolite. Kojic acid exhibited dose-dependent mortality and inhibited the hatchability of M. incognita, showing EC50 values of 195.2 µg/ml and 238.3 µg/ml, respectively, at 72 h postexposure. These results suggest that A. oryzae EML-DML3PNa1 and kojic acid have potential as a biological control agent against M. incognita.

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

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Donggeun Kim

2013-12-01

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

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

Science.gov (United States)

Giné, Ariadna; Sorribas, Francisco J

2017-05-01

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

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

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Stefany Solano-González

2015-06-01

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

Nematicidal activity of crambe extracts on Meloidogyne spp.

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Sidiane Coltro-Roncato

2016-08-01

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

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

Science.gov (United States)

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

2018-03-01

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

Evaluation of in vitro and in vivo nematicidal potential of a multifunctional streptomycete, Streptomyces hydrogenans strain DH16 against Meloidogyne incognita.

Science.gov (United States)

Kaur, Talwinder; Jasrotia, Shivam; Ohri, Puja; Manhas, Rajesh Kumari

2016-11-01

The present work demonstrated the nematicidal potential of Streptomyces hydrogenans strain DH16 (a strain with strong antagonism against fungal phytopathogens and insect pest) against Meloidogyne incognita. The culture supernatant and solvent extract significantly inhibited egg hatching (almost 100%) along with J2 mortality of more than 95% after 96h. The nematicidal activity of 10-(2,2-dimethyl-cyclohexyl)-6,9-dihydroxy-4,9-dimethyl-dec-2-enoic acid methyl ester (SH2; a new antifungal compound) purified from this streptomycete was also evaluated using different concentrations. The juvenile mortality of the nematode increased with increasing concentration and exposure time and reached the maximum (95%) after 96h at concentration of 100μg/ml. After 160h of incubation, egg hatch of 16% was observed at concentration of 100μg/ml as compared to control where 100% egg hatching was achieved. However, at the highest concentration of the compound (200μg/ml), 100% J2 mortality and 0% egg hatching were observed after 72 and 160h of incubation, respectively. In vivo pot experiments further revealed the nematicidal potential of S. hydrogenans where soil drenching with its culture supernatant and cells effectively controlled root galls, egg masses in nematode infested tomato plants and at the same time promoted the growth of tomato plants. Additionally, in the absence of nematodes, soil drenching with culture supernatant and cells significantly enhanced the various agronomic traits of plants as compared to control plants. Thus, the outcomes of the current study endorse the potential of S. hydrogenans strain DH16 and its metabolites to be developed as safe nematicidal and plant growth promoting agents. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

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Gelpud Chaves Cristian

2011-03-01

Full Text Available

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

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

Directory of Open Access Journals (Sweden)

Santos Nélida Murga-Gutiérrez

2013-06-01

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

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

International Nuclear Information System (INIS)

Hammach, M.

2010-01-01

Crops under greenhouses offer the possibility of vegetables production of high added value by focusing on earliness. They help to spread the availability timing of vegetables and fruits in the market throughout the year. However, these crops are subject to numerous attacks entailing heavy losses of yield quantity and quality. The plant parasitic nematodes especially rot-knot nematodes of the genus Meloidogyne are considered dangerous enemies of these cultures. The evolution study of these nematodes in different soil types allows one to compare the migration and movement of these nematodes in sandy soils considered as light soils, in clay soils heavy and intermediate silty clay soils. These soils have also rates of organic matter and a percentage of magnesium and calcium that might provide better conditions to the survival and migration of second stage larvae inoculated at a rate of 650 juveniles per pot of 24 cm in diameter where plants of melon Cucumis melo var. (Charentais) known to be susceptible to Meloidogyne was cultivated. The results for the population development of Meloidogyne, after a growing period of 3 months show an increase in the number of eggs, juvenile stages, inflated, swollen females and males in the 3 types of soil and that independently of clay fraction although clay soil may asphyxiate Meloidogyne. The development of the three species of Meloidogyne studied in these soils, the parameters taken into consideration (index of galls, which were 1.58, 1.75 and 1.5 for the sandy clay and the middle ground soils, vigour index and the evolution of populations of Meloidogyne and roots and soil as well as parameters related to production reveal the adaptation of these root-knot nematodes to the clay and sandy loam soils. At the end of culture, the final populations are important in the soils studied; 2680 for soil S. (sandy), 2272 for soil A (clay) and 2327 for soil I (intermediate) with a multiplication rate almost similar ( 4.12, 3.49 and 3

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

Science.gov (United States)

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

2016-09-01

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

Induction of SA-signaling pathway and ethylene biosynthesis in Trichoderma harzianum-treated tomato plants after infection of the root-knot nematode Meloidogyne incognita.

Science.gov (United States)

Leonetti, Paola; Zonno, Maria Chiara; Molinari, Sergio; Altomare, Claudio

2017-04-01

Salicylic acid-signaling pathway and ethylene biosynthesis were induced in tomato treated with Trichoderma harzianum when infected by root-knot nematodes and limited the infection by activation of SAR and ethylene production. Soil pre-treatment with Trichoderma harzianum (Th) strains ITEM 908 (T908) and T908-5 decreased susceptibility of tomato to Meloidogyne incognita, as assessed by restriction in nematode reproduction and development. The effect of T. harzianum treatments on plant defense was detected by monitoring the expression of the genes PR-1/PR-5 and JERF3/ACO, markers of the SA- and JA/ET-dependent signaling pathways, respectively. The compatible nematode-plant interaction in absence of fungi caused a marked suppression of PR-1, PR-5, and ACO gene expressions, either locally or systemically, whilst expression of JERF3 gene resulted unaffected. Conversely, when plants were pre-treated with Th-strains, over-expression of PR-1, PR-5, and ACO genes was observed in roots 5 days after nematode inoculation. JERF3 gene expression did not change in Th-colonized plants challenged with nematodes. In the absence of nematodes, Trichoderma-root interaction was characterized by the inhibition of both SA-dependent signaling pathway and ET biosynthesis, and, in the case of PR-1 and ACO genes, this inhibition was systemic. JERF3 gene expression was systemically restricted only at the very early stages of plant-fungi interaction. Data presented indicate that Th-colonization primed roots for Systemic Acquired Resistance (SAR) against root-knot nematodes and reacted to nematode infection more efficiently than untreated plants. Such a response probably involves also activation of ET production, through an augmented transcription of the ACO gene, which encodes for the enzyme catalyzing the last step of ET biosynthesis. JA signaling and Induced Systemic Resistance (ISR) do not seem to be involved in the biocontrol action of the tested Th-strains against RKNs.

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

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Ni Xiang

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

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

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Hendrika Fourie

2015-09-01

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

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

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Nadya Lorena Cardona Bustos

2008-12-01

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

Effect of Emamectin Benzoate on Root-Knot Nematodes and Tomato Yield

OpenAIRE

Cheng, Xingkai; Liu, Xiumei; Wang, Hongyan; Ji, Xiaoxue; Wang, Kaiyun; Wei, Min; Qiao, Kang

2015-01-01

Southern root-knot nematode (Meloidogyne incognita) is an obligate, sedentary endoparasite of more than 3000 plant species, that causes heavy economic losses and limit the development of protected agriculture of China. As a biological pesticide, emamectin benzoate has effectively prevented lepidopteran pests; however, its efficacy to control M. incognita remains unknown. The purpose of the present study was to test soil application of emamectin benzoate for management of M. incognita in labor...

African Journal of Biotechnology - Vol 10, No 44 (2011)

African Journals Online (AJOL)

The effect of zinc application methods on seed cotton yield, lint and seed quality of ... Management of Meloidogyne incognita in nematodesusceptible watermelon ... Waste cooking oil transesterification: Influence of impeller type, temperature, ...

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

OpenAIRE

Fassuliotis, G.; Bhatt, D. P.

1982-01-01

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

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

Directory of Open Access Journals (Sweden)

Juan Carlos Álvarez-Hernández

2015-08-01

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

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

Science.gov (United States)

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

A farmer friendly and economic IPM strategy to combat root-knot nematodes infesting lentil

OpenAIRE

Rose Rizvi; Rizwan Ali Ansari; Gulshan Zehra; Irshad Mahmood

2015-01-01

An experiment was conducted to assess the effect of Rhizobium sp., waste tea leaves, eggshell powder, and composted cow dung manure on the root-knot nematode, Meloidogyne incognita, on lentil in Botany department AMU, Aligarh, India. When used alone, composted cow dung was better in reducing galling and nematode multiplication and improving lentil growth followed by eggshell powder, Rhizobium sp., and waste tea leaves. Significant result in the integrated management of M. incognita was obtain...

Detectie van Meloidogyne spp. in grondmonsters - een vergelijking van twee technieken

NARCIS (Netherlands)

Veenhuizen, P.T.M.; Schoemakers, N.; Vos, J.; Versteegen, F.; Landeweert, R.; Karssen, G.

2007-01-01

Hier volgen de samenvattingen van de bijeenkomst van 20 maart 2007 van de KNPV-werkgroep Meloidogyne. 1) Kwantitatieve multiplexdetectie van aaltjes; 2). Meloidogyne chitwoodi en M. fallax: vergelijking visuele beoordeling en Taqman-PCR aan pootaardappelen; 3) Detectie van Meloidogyne spp. in

Protection of olive planting stocks against parasitism of root-knot nematodes by arbuscular mycorrhizal fungi

OpenAIRE

Castillo, Pablo; Nico, Andrés I.; Azcón González de Aguilar, Concepción; Río Rincón, C. del; Calvet, Cinta; Jiménez-Díaz, Rafael M.

2006-01-01

The effects were investigated, under controlled conditions, of single and joint inoculation of olive planting stocks cvs Arbequina and Picual with the arbuscular mycorrhizal fungi (AMF) Glomus intraradices, Glomus mosseae or Glomus viscosum, and the root-knot nematodes Meloidogyne incognita and Meloidogyne javanica, on plant performance and nematode infection. Establishment of the fungal symbiosis significantly increased growth of olive plants by 88·9% within a range of 11·9–214·0%, ...

Author Details

African Journals Online (AJOL)

friendly management of root-knot nematodes, Meloidogyne incognita on tomato. Abstract PDF · Vol 4, No 3 (2015) - Articles Evaluation of different strains of eri silkworms (Samia cynthia ricini B.) for their adaptability and silk yield in Ethiopia

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

Science.gov (United States)

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

Biologische grondontsmetting bij de teelt van trekheesters: Implementatie van een alternatieve ontsmettingsmerhode in de praktijk

NARCIS (Netherlands)

Ludeking, D.J.W.; Hamelink, R.; Bloemhard, C.M.J.; Slooten, van M.A.

2011-01-01

This report is about biological soil disinfestation with an organic product named Herbie 7022. The effect has been investigated against Verticillium dahliae, Meloidogyne incognita and larvae of Serica brunnea. All larvae of Serica brunnea are killed after application of a period of anaerobic

Gas Chromatography-Mass Spectrometric Analysis of Essential Oil ...

African Journals Online (AJOL)

Conclusion: The study indicates that the essential oil of G. parviflora aerial parts has a potential for development into a natural insecticide/nematicide for control of nematodes and grain storage insects. Keywords: Glycosmis parviflora, Essential oil, Meloidogyne incognita, Sitophilus zeamais, Triboliumcastaneum, Contact ...

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

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Francisco José Carvalho Moreira

2017-10-01

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

Screening edible ginger and turmeric cultivars for resistance to root-knot nematodes

Science.gov (United States)

Twenty-two edible ginger and turmeric cultivars were screened for resistance or tolerance to Meloidogyne incognita. Plants were raised in 66 L grow bags in greenhouses in Hawaii according to established practices for producing bacterial wilt-free ginger. Three months after planting, each grow bag ...

Effect of Emamectin Benzoate on Root-Knot Nematodes and Tomato Yield.

Science.gov (United States)

Cheng, Xingkai; Liu, Xiumei; Wang, Hongyan; Ji, Xiaoxue; Wang, Kaiyun; Wei, Min; Qiao, Kang

2015-01-01

Southern root-knot nematode (Meloidogyne incognita) is an obligate, sedentary endoparasite of more than 3000 plant species, that causes heavy economic losses and limit the development of protected agriculture of China. As a biological pesticide, emamectin benzoate has effectively prevented lepidopteran pests; however, its efficacy to control M. incognita remains unknown. The purpose of the present study was to test soil application of emamectin benzoate for management of M. incognita in laboratory, greenhouse and field trials. Laboratory results showed that emamectin benzoate exhibited high toxicity to M. incognita, with LC50 and LC90 values 3.59 and 18.20 mg L(-1), respectively. In greenhouse tests, emamectin benzoate soil application offered good efficacy against M. incognita while maintaining excellent plant growth. In field trials, emamectin benzoate provided control efficacy against M. incognita and resulted in increased tomato yields. Compared with the untreated control, there was a 36.5% to 81.3% yield increase obtained from all treatments and the highest yield was received from the highest rate of emamectin benzoate. The results confirmed that emamectin benzoate has enormous potential for the control of M. incognita in tomato production in China.

Effect of Emamectin Benzoate on Root-Knot Nematodes and Tomato Yield.

Directory of Open Access Journals (Sweden)

Xingkai Cheng

Full Text Available Southern root-knot nematode (Meloidogyne incognita is an obligate, sedentary endoparasite of more than 3000 plant species, that causes heavy economic losses and limit the development of protected agriculture of China. As a biological pesticide, emamectin benzoate has effectively prevented lepidopteran pests; however, its efficacy to control M. incognita remains unknown. The purpose of the present study was to test soil application of emamectin benzoate for management of M. incognita in laboratory, greenhouse and field trials. Laboratory results showed that emamectin benzoate exhibited high toxicity to M. incognita, with LC50 and LC90 values 3.59 and 18.20 mg L(-1, respectively. In greenhouse tests, emamectin benzoate soil application offered good efficacy against M. incognita while maintaining excellent plant growth. In field trials, emamectin benzoate provided control efficacy against M. incognita and resulted in increased tomato yields. Compared with the untreated control, there was a 36.5% to 81.3% yield increase obtained from all treatments and the highest yield was received from the highest rate of emamectin benzoate. The results confirmed that emamectin benzoate has enormous potential for the control of M. incognita in tomato production in China.

In vitro Studies of the Effectiveness of Five Plants Extracts Compared ...

African Journals Online (AJOL)

The crude aqueous extracts of five plants, Cleome viscosa L. Hyptis suaveolens Poit, Crotalaria retusa L., Jatropha curcas L., and Jatropha gossypifolia l., and a synthetic nematicide Carbofuran were studied in-vitro for their efficacy in controlling the rootknot nematode, Meloidogyne incognita (Kofoid and White) Chitwood.

Phenylacetic acid-producing Rhizoctonia solani represses the biosynthesis of nematicidal compounds in vitro and influences biocontrol of Meloidogyne incognita in tomato by Pseudomonas fluorescens strain CHA0 and its GM derivatives.

Science.gov (United States)

Siddiqui, I A; Shaukat, S S

2005-01-01

The aim of the present investigation was to determine the influence of Rhizoctonia solani and its pathogenicity factor on the production of nematicidal agent(s) by Pseudomonas fluorescens strain CHA0 and its GM derivatives in vitro and nematode biocontrol potential by bacterial inoculants in tomato. One (Rs7) of the nine R. solani isolates from infected tomato roots inhibited seedling emergence and caused root rot in tomato. Thin layer chromatography revealed that culture filtrates of two isolates (Rs3 and Rs7) produced brown spots at Rf-values closely similar to synthetic phenylacetic acid (PAA), a phytotoxic factor. Filtrates from isolate Rs7, amended with the growth medium of P. fluorescens, markedly repressed nematicidal activity and PhlA'-'LacZ reporter gene expression of the bacteria in vitro. On the contrary, isolate Rs4 enhanced nematicidal potential of a 2,4-diacetylphloroglucinol overproducing mutant, CHA0/pME3424, of P. fluorescens strain CHA0 in vitro. Therefore, R. solani isolates Rs4 and Rs7 were tested more rigorously for their potential to influence biocontrol effectiveness of the bacterial agents. Methanol extract of the culture filtrates of PAA-producing isolate Rs7 resulting from medium amended with phenylalanine enhanced fungal repression of the production of nematicidal agents by bacteria, while amendments with zinc or molybdenum eliminated such fungal repression, thereby restoring bacterial potential to cause nematode mortality in vitro. A pot experiment was carried out, 3-week-old tomato seedlings were infested with R. solani isolates Rs4 or Rs7 and/or inoculated with Meloidogyne incognita, the root-knot nematode. The infested soil was treated with aqueous cell suspensions (10(8) CFU) of P. fluorescens strain CHA0 or its GM derivatives or left untreated (as a control). Observations taken 45 days after nematode inoculation revealed that, irrespective of the bacterial treatments, galling intensity per gram of fresh tomato roots was markedly

Effects of Methanolic Extracts from the Leaves of Brimstone, Cassia ...

African Journals Online (AJOL)

Effects of Methanolic Extracts from the Leaves of Brimstone, Cassia, Lemon Grass and Chanca Piedra on Meloidogyne Incognita in the Laboratory. ... and the highest level (20%) of aqueous extracts of all test plants completely inhibited egg hatch while the control (distilled water only) recorded 93% commulative egg hatch.

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

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Iva Tomalova

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

Effect of tillage and fumigation on Pasteuria penetrans

Science.gov (United States)

The endospore-forming bacterium Pasteuria penetrans (Pp) is a parasite of Meloidogyne spp. In this study, the effect of tillage and the fumigant 1,3-dichloropropene (1,3-D) on numbers of Pp and suppression of M. incognita (Mi) was evaluated from 2011-2013. A split-plot experiment was established i...

Nematicidal influence of P.tuberreguim and neem extract on the ...

African Journals Online (AJOL)

Efficacy of Pleurotus tuberregium, Neem-leaf ash, carbofuram and combination of the three above were tested in the control of root-knot nematode (Meloidogyne incognita) on Hausa potato. In the green house, twenty-five polythene bags were filled with 10kg of steam-sterilized sandy loam soil and Hausa potato seedlings ...

Reaction of some selected soybean varieties ( Glycine max (L) Merril)

African Journals Online (AJOL)

In nematode endemic ecological zones, TGX-1985 – 8F is therefore recommended as it proved to contain some specialized genes that conferred a higher level of tolerance against root- knot nematode, Meloidogyne incognita. Key Words: Glycine max, root – knot nematode, Dominant loci, Mi – 1.2, leucine zipper and R ...

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

International Nuclear Information System (INIS)

Nyongesa, W.M.

2002-01-01

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

Identifikasi Fusarium dan Nematoda Parasitik yang Berasosiasi dengan Penyakit Kuning Lada di Kalimantan Barat

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Suryanti Suryanti

2015-07-01

Full Text Available Pepper (Piper nigrum, known as the “King of Spices” is one of the most important spices. In the international market, Indonesian pepper has high selling value, due to its flavor characteristics. Pepper yellowing disease is one of the most important disease that caused the decrease of pepper production and become the main problem in the cultivation of pepper in West Kalimantan. This research was conducted to determine the major causal agent of leaf yellowing disease of pepper. The Fusarium associated with diseased plant were isolated from the symptomatic plant and nematodes were isolated from the root with leaf yellowing symptom. The Fusarium isolates were cultured on agar medium, and the nematode was cultured on tomato plant. From diseased pepper in West Kalimantan, it was isolated 4 Fusarium isolates and plant parasitic nematode Meloidogyne. The result showed that H isolate of Fusarium was the most virulent isolate and identified asFusarium solani. The Meloidogyne was identified by the female perenial patern.The nematode was identified as Meloidogyne incognita. INTISARI Lada (Piper nigrum L. merupakan salah satu jenis rempah penting yang telah dikenal sebagai “King of Spices”. Di pasar internasional, lada Indonesia mempunyai daya jual tinggi karena cita rasanya yang khas. Salah satu kendala dalam budidaya lada adalah adanya penyakit kuning lada dan sampai saat ini menjadi masalah utama pada pertanaman lada di Kalimantan Barat. Informasi tentang patogen utama yang berinteraksi dengan penyakit kuning lada masih sangat terbatas, sehingga penelitian ini bertujuan untuk mengidentifikasi patogen utama yang berasosiasi dengan penyakit kuning lada. Isolasi Fusarium dilakukan dari batang lada dan isolasi nematoda dilakukan dari akar lada yang bergejala penyakit kuning di Kalimantan Barat. Fusarium hasil isolasi dikulturkan dalam medium agar, sedangkan nematoda hasil isolasi dikulturkan dalam akar tomat. Dari hasil isolasi berhasil didapatkan

Efeito do Meloidogyne javanica no crescimento da ervilha Effect of Meloidogyne javanica on the growth of pea

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Ravi Datt Sharma

2000-01-01

Full Text Available O nematóide-das-galhas radiculares, Meloidogyne javanica, comumente causa redução em produtividade de ervilha, Pisum sativum L., no Distrito Federal. O efeito de Meloidogyne javanica no crescimento da ervilha cv. Triofin foi avaliado em cinco níveis de inóculos: 0, 10, 100, 1.000 e 10.000 ovos/kg de solo, em casa de vegetação. Houve redução progressiva no crescimento da planta com o aumento do inóculos. O fator de multiplicação foi negativamente proporcional ao inóculo inicial. A nodulação bacteriana também foi seriamente afetada em todos os níveis de inóculo, exceto no de 10 ovos/kg do solo, que apresentou 61,63% de aumento no de número de nódulos/planta.The root-knot nematode, Meloidogyne javanica commonly causes yield reduction of pea (Pisum sativum L. in the Federal District of Brazil. The effect of M. javanica on the growth of pea cv. Triofin was studied with five inoculum levels namely 0, 10, 100, 1,000, and 10,000 eggs/kg of soil under greenhouse conditions. There was a progressive decrease in plant growth as the inoculum levels of nematode increased. The rate of nematode multiplication was inversely proportional to the inoculum level. Rhizobial nodulation was adversely affected at all the inoculum levels except for the inoculum level of 10 eggs/kg of soil which showed a 61.63% increase in number of bacterial nodules.

Morphological and molecular characteristics of a new species of Pasteuria parasitic on Meloidogyne ardenensis.

Science.gov (United States)

Bishop, Alistair H; Gowen, Simon R; Pembroke, Barbara; Trotter, James R

2007-09-01

A species of the hyper-parasitic bacterium Pasteuria was isolated from the root-knot nematode Meloidogyne ardenensis infecting the roots of ash (Fraxinus excelsior). It is morphologically different from some other Pasteuria pathogens of nematodes in that the spores lack a basal ring on the ventral side of the spore and have a unique clumping nature. Transmission electron microscopy (TEM) showed that the clumps of spores are not random aggregates but result from the disintegration of the suicide cells of the thalli. Sporulation within each vegetative mycelium was shown to be asynchronous. In addition to the novel morphological features 16S rRNA sequence analysis showed this to be a new species of Pasteuria which we have called P. hartismeri. Spores of P. hartismeri attach to juveniles of root-knot nematodes infecting a wide range of plants such as mint (Meloidogyne hapla), rye grass (unidentified Meloidogyne sp.) and potato (Meloidogyne fallax).

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

Science.gov (United States)

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

2016-04-01

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

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

Science.gov (United States)

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

1973-04-01

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.

Seleção para resistência de genótipos de cenoura aos nematóides-das-galhas Selection for carrot genotypes resistance to root-knot nematodes in field and greenhouse

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Giovani O da Silva

2011-09-01

Full Text Available Foi verificada a relação entre caracteres avaliados em campo e casa-de-vegetação, relativos à avaliação de genótipos de cenoura quanto à resistência ao nematóide-das-galhas (Meloidogyne spp., visando identificar quais caracteres possibilitam a diferenciação entre os genótipos e verificar a possibilidade de avaliação apenas em um ambiente ou a eliminação de caracteres que apresentem correlação alta. Avaliaram-se 38 progênies da população '0812518' e 31 progênies da população '0812519', além das cultivares Brasília e Kuronan como testemunhas tolerante e suscetível, respectivamente. Em campo naturalmente infestado por uma mistura de Meloidogyne incognita raça 1 e Meloidoigyne javanica, a seleção para resistência ao nematóide-das-galhas foi realizada com base na menor porcentagem de infecção na raiz principal dos genótipos de cenoura, rendimento de raiz e o fator de reprodução, enquanto que em casa-de-vegetação, para cada uma das mesmas espécies de nematóides e também para a mistura de ambas, foi medido o índice de galhas e índice de massa de ovos. Verificou-se que não houve possibilidade de seleção em apenas um dos ambientes testados ou a eliminação de caracteres, indicando que para a obtenção de cultivares mais produtivas e mais tolerantes é necessária a seleção combinada nos diferentes caracteres e ambientes. Para o experimento realizado em campo foi possível diferenciar os genótipos apenas para o rendimento de raiz. No experimento em casa-de-vegetação, para todos os caracteres foi possível identificar genótipos superiores. Porém, as médias das populações não foram melhores que a testemunha 'Brasília' da qual estas se originaram, confirmando a necessidade da busca por métodos mais eficientes de seleção.We verified the relation among the evaluated characters in field and greenhouse, concerning to the evaluation to root-knot nematode (Meloidogyne spp. for the carrot crop, to

Eficácia da ivermectina comprimido no tratamento da sarna sarcóptica em cães naturalmente infestados

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Gisele Maria de Andrade

Full Text Available RESUMO: O objetivo deste trabalho foi avaliar a eficácia da ivermectina comprimido administrada por via oral no tratamento de Sarcoptes scabiei em cães naturalmente infestados. Foram selecionados 14 cães com raspados cutâneos positivos para o ácaro S. scabiei, idade de 1-5 anos, sem raça definida, distribuídos na mesma proporção de ambos os sexos, em dois grupos experimentais, compondo 7 animais por grupo. Todos os animais foram tratados a cada 7 dias, totalizando quatro tratamentos em cada cão (Dias 0,7,14 e 21. No grupo I foi administrada a ivermectina5 comprimido na dosagem de 0,2mg/kg e no grupo controle positivo (Grupo II foi administrado um produto comercial a base de ivermectina comprimido na mesma dosagem do grupo I. Raspados cutâneos, avaliações clinicas e laboratoriais complementares dos cães foram realizadas durante o período de estudo. Clinicamente, não houve diferença significativa entre as avaliações antes e após o tratamento entre os dois grupos. Raspados negativos foram observados em ambos os grupos a partir do dia D+14, mantendo-se negativos até o final do período experimental. As lesões dermatológicas iniciais observadas no acompanhamento clínico regrediram e a partir do dia D+14 a melhora clínica era evidente em ambos os grupos. A ivermectina (Ivermectan Pet, UCBVET Saúde Animal administrada por via oral foi eficaz no tratamento de S. scabiei em cães naturalmente infestados.

Rme1 is necessary for Mi-1-mediated resistance and acts early in the resistance pathway.

Science.gov (United States)

Martinez de Ilarduya, Oscar; Nombela, Gloria; Hwang, Chin-Feng; Williamson, Valerie M; Muñiz, Mariano; Kaloshian, Isgouhi

2004-01-01

The tomato gene Mi-1 confers resistance to root-knot nematodes (Meloidogyne spp.), potato aphid, and whitefly. Using genetic screens, we have isolated a mutant, rme1 (resistance to Meloidogyne spp.), compromised in resistance to M. javanica and potato aphid. Here, we show that the rme1 mutant is also compromised in resistance to M. incognita, M. arenaria, and whitefly. In addition, using an Agrobacterium-mediated transient assay in leaves to express constitutive gain-of-function mutant Pto(L205D), we demonstrated that the rme1 mutation is not compromised in Pto-mediated hypersensitive response. Moreover, the mutation in rme1 does not result in increased virulence of pathogenic Pseudomonas syringae or Mi-1-virulent M. incognita. Using a chimeric Mi-1 construct, Mi-DS4, which confers constitutive cell death phenotype and A. rhizogenes root transformation, we showed that the Mi-1-mediated cell death pathway is intact in this mutant. Our results indicate that Rme1 is required for Mi-1-mediated resistance and acts either at the same step in the signal transduction pathway as Mi-1 or upstream of Mi-1.

Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes

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Tushar Kanti Dutta

2015-04-01

Full Text Available Root-knot nematodes (Meloidogyne incognita cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco and soybean that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1, was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60-80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants.

JST Thesaurus Headwords and Synonyms: Meloidogyne [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Meloidogyne 名詞 一般 * * * * ネコブセンチュ...ウ ネコブセンチュウ ネコブセンチュー Thesaurus2015 200906002822195970 C LS05 UNKNOWN_1 Meloidogyne

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

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B. Triman

2001-07-01

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

Isolation of Antagonistic Endophytes from Banana Roots against Meloidogyne javanica and Their Effects on Soil Nematode Community

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Lanxi Su

2017-10-01

Full Text Available Banana production is seriously hindered by Meloidogyne spp. all over the world. Endophytes are ideal candidates compared to pesticides as an environmentally benign agent. In the present study, endophytes isolated from banana roots infected by Meloidogyne spp. with different disease levels were tested in vitro, and in sterile and nature banana monoculture soils against Meloidogyne javanica. The proportion of antagonistic endophytes were higher in the roots of middle and high disease levels. Among those, bacteria were dominant, and Pseudomonas spp., Bacillus spp. and Streptomyces spp. showed more abundant populations. One strain, named as SA, with definite root inner-colonization ability was isolated and identified as Streptomyces sp. This strain showed an inhibiting rate of >50% in vitro and biocontrol efficiency of 70.7% in sterile soil against Meloidogyne javanica, compared to the control. Greenhouse experiment results showed that the strain SA exhibits excellent biological control ability for plant-parasites both in roots and in root-knot nematode infested soil. SA treatment showed a higher number of bacterivores, especially Mesorhabditis and Cephalobus. The maturity index was significantly lower, while enrichment index (EI was significantly higher in the SA treatment. In conclusion, this study presents an important potential application of the endophytic strain Streptomyces sp. for the control of plant-parasitic nematodes, especially Meloidogyne javanica, and presents the effects on the associated variation of the nematode community.

Fatal verminous pharyngitis and esophagitis caused by Streptocara incognita in mute swans (Cygnus olor).

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Alić, A; Prasović, S; Hodzić, A; Besirović, H; Residbegović, Emina; Omeragić, J

2013-03-01

Streptocara spp. infections are reported to cause gastritis, proventriculitis, esophagitis, and pharyngitis in various waterfowls, especially diving ducks. In the present paper, we describe severe fatal diphtheritic pharyngitis and esophagitis caused by Streptocara incognita in three female mute swans (Cygnus olor) in Bosnia and Herzegovina. Prior to death, the swans were showing signs of lethargy, anorexia, and reluctance to move. At necropsy, in all swans severe diphtheritic pharyngitis and esophagitis with deep, dark red hemorrhagic ulcerations were observed. Numerous thin, white, up to 1-cm-long nematodes, identified as S. incognita, were observed embedded in the pharyngeal and esophageal mucosa under the diphtheritic membranes. Histopathology revealed severe fibrinonecrotic inflammation with numerous cross-sections of the parasites. To the authors' knowledge, this is the first report of severe, fatal streptocariasis in mute swans.

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

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Hirunsalee, A; Barker, K R; Beute, M K

1995-06-01

A 3-year microplot study was initiated to characterize the population dynamics, reproduction potential, and survivorship of single or mixed populations of Meloidogyne arenaria race 1 (Ma1) and race 2 (Ma2), as affected by crop rotations of peanut 'Florigiant' and M. incognita races 1 and 3-resistant 'McNair 373' and susceptible 'Coker 371-Gold' tobacco. Infection, reproduction, and root damage by Ma2 on peanut and by Ma1 on resistant tobacco were limited in the first year. Infection, reproduction, and root-damage potentials on susceptible tobacco were similar for Ma1 and Ma2. In the mixed (1:1) population, Ma1 was dominant on peanut and Ma2 was dominant on both tobacco cultivars. Crop rotation affected the population dynamics of different nematode races. For years 2 and 3, the low numbers of Ma1 and Ma2 from a previous-year poor host increased rapidly on suitable hosts. Ma1 had greater reproduction factors ([RF] = population density at harvest/population density at preplandng) than did Ma2 and Ma1 + Ma2 in second-year peanut plots following first-year resistant tobacco, and in third-year peanut plots following second-year tobacco. In mixed infestations, Ma1 predominated over Ma2 in previous-year peanut plots, whereas Ma2 predominated over Ma1 in previous-year tobacco plots. Moderate damage on resistant tobacco was induced by Ma1 in the second year. In the third year, moderate damage on peanut was associated with 'Ma2' from previous-year peanut plots. The resistant tobacco supported sufficient reproduction of Ma1 over 2 years to effect moderate damage and yield suppression to peanut in year 3.

Development and reproductive potential of Tyrophagus putrescentiae (Acari: Acaridae) on plant-parasitic nematodes and artificial diets.

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Abou El-Atta, Doaa Abd El-Maksoud; Osman, Mohamed Ali

2016-04-01

This study investigated development, reproduction and life table parameters of the astigmatid mold mite Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) feeding on egg-masses or adult females of the nematode Meloidogyne incognita, egg-masses of the nematode Rotylenchulus reniformis, ras cheese or yeast at 25 ± 1 °C, 70 ± 10 % RH in the dark. Immature developmental times were shorter when the mite was fed females of M. incognita followed by yeast. Different prey/diet types had no significant effect on longevity and lifespan of both males and females. Daily oviposition rate (eggs/female/day) was highest for mites fed yeast (20.8 ± 1.8 eggs) and lowest for mites fed females of M. incognita (6.6 ± 0.5). Intrinsic rate of natural increase (r m) was highest for mites fed yeast compared to other prey/diet; no significant differences in r m were observed among mites fed on non-yeast diets. This result may suggest a role of T. putrescentiae as biocontrol agent of plant-parasitic nematodes and the yeast may be used for mite mass-production purposes.

Characteristics and Efficacy of a Sterile Hyphomycete (ARF18), a New Biocontrol Agent for Heterodera glycines and Other Nematodes

OpenAIRE

Kim, D. G.; Riggs, R. D.

1991-01-01

A filamentous, nonsporulating fungus, designated Arkansas Fungus 18 (ARF18), was isolated from 9 of 95 populations of Heterodera glycines, the soybean cyst nematode, in Arkansas. In petri dishes, ARF18 parasitized 89% of H. glycines eggs in cysts. The fungus also infected eggs of Meloidogyne incognita and eggs in cysts of Cactodera betulae, H. graminophila, H. lespedezae, H. leuceilyma, H. schachtii, and H. trifolii. In pot tests, reproduction of SCN was 70% less in untreated field soil that ...

Root-Knot Nematode Management in Double-Cropped Plasticulture Vegetables

OpenAIRE

Desaeger, J. A.; Csinos, A. S.

2006-01-01

Combination treatments of chisel-injected fumigants (methyl bromide, 1,3-D, metam sodium, and chloropicrin) on a first crop, followed by drip-applied fumigants (metam sodium and 1,3-D ± chloropicrin) on a second crop, with and without oxamyl drip applications were evaluated for control of Meloidogyne incognita in three different tests (2002 to 2004) in Tifton, GA. First crops were eggplant or tomato, and second crops were cantaloupe, squash, or jalapeno pepper. Double-cropped vegetables suffe...

Interactions between fodder radish and tagetes varieties and Meloidogyne hapla populations

NARCIS (Netherlands)

Lammers, J.

2013-01-01

In this study, resistance to Meloidogyne hapla populations is the focal point. It involves a screening of fodder radish and Tagetes varieties with a number of local M. hapla populations to determine their infection rate.

Distribution, hosts and identification of Meloidogyne partityla in the USA

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Pecan, Carya illinoensis, is an economically important nut crop and member of the Juglandaceae native to the southern USA. Discovered in South Africa in 1986, Meloidogyne partityla was first found infecting pecan in USA in 1996 and currently occurs in Texas, New Mexico, Georgia, Arizona, Oklahoma a...

Use of organic waste as biofumigant for controlling root knot nematodes (Meloidogyne spp.) on potato

Science.gov (United States)

Sari, D. I. P.; Lisnawita; Oemry, S.; Safni, I.; Lubis, K.; Tantawi, A. R.

2018-02-01

Root knot nematode (Meloidogyne spp.) is one of the important pathogens that causes big impact on potato crop yields. One of the control strategies for controlling this nematode is the use of biofumigants. Biofumigants are volatile toxic compound derived from plants, and have biocide properties against insects and plant pathogens. Organic waste such as Brassicaceae, Leguminoceae, and Solanaceae can be used as biofumigant sources. This research was conducted to determine the effectiveness of Brassicaceae, Leguminoceae, and Solanaceae as biofumigants against Meloidogyne spp. The experiment was set in a completely randomized design (CRD) with the treatments were organic wastes including Brassicaceae, Leguminoceae, and Solanaceae, both single and combinations, and 2 controls (positive and negative controls) with 3 replications. Each of the biofumigant treatments was prepared and stored for 2 weeks. Potato tubers were transplanted 15 days after germination into polybag inoculated with 1,000 Meloidogyne spp. J2s. The results showed that Brassicaceae + Solanaceae were effective in decreasing the number of galls in potato plants, however only Solanaceae improved plant growth.

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

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Luiz Gonzaga E. Lordello

1956-01-01

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

Occurrence of Meloidogyne fallax in North America, and molecular characterization of M. fallax and M. minor from U.S. golf course greens

Science.gov (United States)

Several species of root-knot nematodes (Meloidogyne spp.) are known to have significant presence on turf grass in golf course greens, particularly in the western United States. Nematodes isolated from a golf course in King Co., Washington were identified as Meloidogyne minor based on analysis of the...

Nematodos agalladores asociados al cultivo de papaya (Carica papaya L. en el departamento de Córdoba, Colombia

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Jaraba Juan de Dios

2007-06-01

Full Text Available

El objetivo de este trabajo fue identificar los nematodos agalladores asociados al cultivo de papaya (Carica papaya L. en los municipios de Tierralta, Valencia, Lorica, Montería y Montelíbano que constituyen el área productora de papaya en Córdoba. Se evaluaron variables morfológicas y morfométricas en hembras, machos y juveniles de segundo estadío (J2. En las muestras de suelo se determinó pH, contenido de materia orgánica (MO, conductividad eléctrica (CE y textura, a fin de correlacionarlas con la presencia de especies nematodas. Se encontraron Meloidogyne javanica,M. incognita y M. arenaria, siendo M. incognita la especie más frecuente. Las tres especies se encontraron mezcladas en 37,5% de los individuos;M. incognita y M. arenaria en 50%, mientras que M. incognita y M. javanica no se encontraron mezcladas. Las especies se encontraron en pH de 4,9 a 6,4; CE de 0,1 a 0,45 dS· m^-1; MO de 1,2 % a 2,5 % y la textura fue arenosa, franca y franco arenosa. El pH, el contenido de arena y la CE correlacionan de manera positiva con la presencia de los nematodos, mientras la MO mostró correlación negativa. Se reporta por primera vez la ocurrencia de M. javanica, M. incognita, M. arenaria, así como la mezcla de M. incognita y M. arenaria, en papayas de Colombia.

POTENSI BAKTERI ENDOFIT AKAR UBI JALAR (IPOMOEA BATATAS L. ASAL KABUPATEN SORONG PAPUA BARAT SEBAGAI AGENSIA BIOKONTROL MELOIDOGYNE SPP.

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Tuminem .

2016-03-01

Full Text Available Potency of sweetpotato (Ipomoea batatas L. root endophytic bacteria from Sorong District West Papua as biocontrol agent of Meloidogyne spp. Root knot nematodes/RKN, Meloidogyne spp. is one of the important pathogens in sweet potato plant. The disease incidence rate by the RKN on sweetpotato crop in Sorong District reached 88.77%. This study aims to get the sweet potato root endophytic bacteria that have potential as biocontrol agents against Meloidogyne spp. Endophytic bacteria was isolated from the roots of healthy sweet potato sampled from Sorong District, West Papua Province. Isolation and selection of bacteria using TSA media. Selected bacterial isolates, which were non-pathogenic to plants and humans then were identified with PCR technique using universal primer 63-F / 1387-R. The ability of bacteria to produce the lipase enzyme was selected using the media NB agar and rhodamine B. The protease enzyme-producing bacteria were selected using skim milk media. The chitinase enzyme-producing bacteria were selected using the colloidal chitin media. Production of cyanide was detected using filter paper soaked in a solution of CDS. The effectiveness of culture filtrate of bacteria as biocontrol agents was measured based on the percentage of 2nd juvenile mortality and egg hatching of Meloidogyne spp. Four isolates of endophytic bacteria, that were Enterobacter sp EAS (1a, Enterobacter sp. EAS (3a Enterobacter ludwigii EAS (4, and Burkholderia cepacia EAS (6 produced lipase and protease. In addition, B. cepacia EAS (6 also produced chitinase. Those isolates caused mortality of the 2nd juvenile 81.4 to 95.2% and inhibited the egg hatching of Meloidogyne spp. 53.13 to 81.92%.

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

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Mohamed Adam

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

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

Science.gov (United States)

Adam, Mohamed; Heuer, Holger; Hallmann, Johannes

2014-01-01

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

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

African Journals Online (AJOL)

SARAH

2013-09-30

Sep 30, 2013 ... ELISA detected Bt protein in soil and roots of Bt cotton but not in HART 89M ... as the use of organic amendments and nematicides with other .... isogenic counterpart to test the effect of the Bt gene ..... Bendezu and Starr (2003) identified two types of RKN ... soil texture, temperature, moisture, aeration and.

Control of Meloidogyne incognita (kofoid and white) chitwood (root ...

African Journals Online (AJOL)

Screenhouse experiments were conducted to test the efficacy of cowdung and urine separately and in combination in the control of root-knot nematode of tomato. Equal quantities of cowdung, urine and their mixture were separately made up to one litre with autoclaved soil. Two weeks old seedlings of tomato raised in ...

Influence of root exudates on attachment of Pasteuria penetrans to Meloidogyne arenaria

Science.gov (United States)

We hypothesized that root exudates would influence the spore attachment of Pasteuria penetrans to root-knot nematodes (Meloidogyne arenaria). An experiment was carried out using a factorial arrangement of two single spore (SS) lines cultured from P. penetrans and three single egg mass(SEM)lines cult...

A farmer friendly and economic IPM strategy to combat root-knot nematodes infesting lentil

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Rose Rizvi

2015-12-01

Full Text Available An experiment was conducted to assess the effect of Rhizobium sp., waste tea leaves, eggshell powder, and composted cow dung manure on the root-knot nematode, Meloidogyne incognita, on lentil in Botany department AMU, Aligarh, India. When used alone, composted cow dung was better in reducing galling and nematode multiplication and improving lentil growth followed by eggshell powder, Rhizobium sp., and waste tea leaves. Significant result in the integrated management of M. incognita was obtained when Rhizobium sp. was used in combination with cow dung and eggshell powder (with or without waste tea leaves. Combined application of root nodule bacterium and organic wastes like waste tea leaves, eggshell, and cow dung may be suggested to the farmers/growers or related persons who are having great enthusiasm to establish a lentil production business. Application of these organic materials along with the root nodule bacteria may be helpful to foster soil ecosystem which has been a hot topic in the present scenario.

BASIDIOMYCETE-BASED METHOD FOR BIOCONTROL OF PHYTOPATHOGENIC NEMATODES

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Tiberius BALAEŞ

2015-12-01

Full Text Available Phytopathogenic nematodes represent one of the most important groups of pathogens in crops. The use of chemical to control the nematodes attack in crops is decreasing every year due to the concern of the toxicity and side effects of such compounds. In the course for finding alternatives to the use of chemicals, biological control of nematodes is gaining much attention. Some saprotrophic fungi are able to feed on invertebrates, thus becoming efficient agents of control. In this study, three species of basidiomycetes were analyzed for their potential to be used as control agents of phytopathogenic nematodes. Through on in vitro investigation of these potential, one strain – Gymnopilus junonius was further selected for a pot test against Meloidogyne incognita, a very important phytopathogenic species of nematodes. The fungal treatment strongly decreased the M. incognita population on the tested pots, proving the potential of G. junonius strain to be used in biocontrol.

First report of the root-knot nematode Meloidogyne ethiopica on tomato in Slovenia

NARCIS (Netherlands)

Sirca, S.; Urek, G.; Karssen, G.

2004-01-01

The root-knot nematode Meloidogyne ethiopica Whitehead originally described from Tanzania is also distributed in South Africa, Zimbabwe, and Ethiopia (3). Although this species is a relatively unknown root-knot nematode, M. ethiopica parasitizes several economical important crops, such as tomato,

Maternal stress reduces the susceptibility of Meloidogyne arenaria progeny to Pasteuria penetrans

Science.gov (United States)

Pasteuria penetrans is an obligate parasite of Meloidogyne spp. Endospores of P. penetrans attach to the cuticle of the second-stage juvenile (J2) and the bacterium completes its life cycle in the mature female nematode; infected females are filled with millions of endospores and produce few to no ...

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

Science.gov (United States)

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

2004-12-01

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

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

NARCIS (Netherlands)

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

2004-01-01

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

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

NARCIS (Netherlands)

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

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

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

NARCIS (Netherlands)

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

2004-01-01

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

The potential of soil fungi associated with potato rhizosphere to control root knot nematode (Meloidogyne spp.) on potato

Science.gov (United States)

Utari, E.; Lisnawita; Safni, I.; Lubis, K.; Tantawi, AR; Hasanuddin

2018-02-01

The root knot nematode (Meloidogyne spp.) is one of important pathogens on potato crops in North Sumatra, Indonesia. This nematode causes significant crop losses on potatoes directly and indirectly. The effect of fungal isolates (Trichoderma sp. 1, Mucor sp.1, Aspergillus sp. 2, Mucor sp. 2) that were isolated from rhizosphere of potato in North Sumatra were studied in green house experiments on the growth of potato and the reproduction of the nematode (Meloidogyne spp). The results showed that Trichoderma sp. 1 caused a significant gall reduction, while Mucor sp.1 and Mucor sp.2 could improve the growth of potato.

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

NARCIS (Netherlands)

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

2014-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-11-01

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

INCASoy-36: soybean variety obtained in Cuba after the induction of mutations with 60Co gamma rays

International Nuclear Information System (INIS)

Ortiz, R; FeII, C de la; Ponce M

2008-01-01

INCASoy-36 variety was obtained after irradiating seeds from INCASoy-15 at doses of 240 Gy 60 Co gamma rays. This variety is adapted to summer and winter seedings; however, it can also be used in spring. Besides, its yields can reach up to 3,5-4,0 t.ha-1 grains in summer and spring seedings. It is tolerant to the main pests and diseases; it is especially resistant to Meloidogyne incognita attacks. During the adverse spring season, seeds have been damage tolerant. It can assure high productions with low inputs; therefore, it is feasible to Cuban agriculture. (Author)

First report of the root-knot nematode Meloidogyne minor on turfgrass in Belgium

NARCIS (Netherlands)

Viaene, N.; Wiseborn, D.B.; Karssen, G.

2007-01-01

The root-knot nematode, Meloidogyne minor, was described during 2004 after it was found on potato roots in a field in the Netherlands and in golf courses in England, Wales, and Ireland (2). Since it is associated with yellow patch disease in turf grass and causes deformation of potato tubers (2), it

Evaluation of steam and soil solarization for Meloidogyne arenaria control in Florida floriculture crops

Science.gov (United States)

Steam and soil solarization were investigated for control of the root-knot nematode Meloidogyne arenaria in two years of field trials on a commercial flower farm in Florida. The objective was to determine if pre-plant steam treatments in combination with solarization, or solarization alone effective...

Uji Patogenisitas Bakteri Pasteuria Penetrans terhadap Nematoda Puru Akar (Meloidogyne spp.

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Mulyadi Mulyadi

1996-12-01

nematodes (Meloidogyne spp. in micro plot and in the field. The pathogenicity study in micro plot was done in Banguntapan, and field experiment was done in Ngipiksari, Pakem, Steman, Yogyakarta. The plots were arranged in Randomized Completely Block Design with three replications. The treatments used in the research were: isolat no. 2 and 3 of P. penetrans; carbofuran nematicide. and control. The results in micro plot test were: 1 root damage caused by root-knot nematodes in plot treated with P. penetrans lower than the control, and 2 percentages of parasitism of P. penetrans were 63.57 % (in isolate no. 2 and 53.46 % (in isolate no. 3. In field experiment the results showed: 1 P. penetrans found to be effective in reducing root damage caused by Meloidogyne spp. especially in 45 days old of tomato plant, whereas in 90 days old the effectiveness were decreased; 2 P. penetrans was able to grow and reproduction in the field: 3 the level of parasitisms of P. penetrans were increased rapidly during the experiment: and 4 the highest yield was found in tomato treated with carbofuran and followed by isolate 2, isolate 3, and control.

Toxicity of 2,4-diacetylphloroglucinol (DAPG) to plant-parasitic and bacterial-feeding nematodes.

Science.gov (United States)

Meyer, Susan L F; Halbrendt, John M; Carta, Lynn K; Skantar, Andrea M; Liu, Ting; Abdelnabby, Hazem M E; Vinyard, Bryan T

2009-12-01

The antibiotic 2,4-diacetylphloroglucinol (DAPG) is produced by some isolates of the beneficial bacterium Pseudomonas fluorescens. DAPG is toxic to many organisms, and crop yield increases have been reported after application of DAPG-producing P. fluorescens. This study was conducted to determine whether DAPG is toxic to selected nematodes. The plant-parasitic nematodes Heterodera glycines, Meloidogyne incognita, Pratylenchus scribneri and Xiphinema americanum, and the bacterial-feeding nematodes Caenorhabditis elegans, Pristionchus pacificus, and Rhabditis rainai, were immersed in concentrations ranging from 0 to 100 μg/ml DAPG. Egg hatch and viability of juveniles and adults were determined. DAPG was toxic to X. americanum adults, with an LD₅₀ of 8.3 μg/ml DAPG. DAPG decreased M. incognita egg hatch, but stimulated C. elegans hatch during the first hours of incubation. Viability of M. incognita J2 and of C. elegans J1 and adults was not affected. There were no observed effects on the other nematodes. The study indicated that DAPG is not toxic to all nematodes, and did not affect the tested species of beneficial bacterial-feeding nematodes. Augmentation of DAPG-producing P. fluorescens populations for nematode biocontrol could be targeted to specific nematode species known to be affected by this compound and by other antibiotics produced by the bacteria, or these bacteria could be used for other possible effects, such as induced plant resistance.

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

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Hyoung Rai Ko

2017-12-01

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

Molecular evidence that Meloidogyne hapla, M. Chitwoodi and M. Fallax are distinct biological entities

NARCIS (Netherlands)

Beek, van der J.G.; Folkertsma, R.; Poley, L.M.; Koert, van P.H.G.; Bakker, J.

1997-01-01

Six isolates of Meloidogyne hapla, including four race A and two race B isolates, eight isolates of M. chitwoodi, and five isolates of M. fallax were submitted to two-dimensional gel electrophoresis (2-DGE) to study the similarity between the various isolates of the three species based upon total

Response of Pinus ponderosa Seedlings to Stylet-Bearing Nematodes

Science.gov (United States)

Viglierchio, D. R.

1979-01-01

Of 12 stylet-bearing nematodes used for inoculations, Pratylenchus penetrans, P. brachyurus, P. vulnus, Ditylenchus destructor, Meloidogyne incognita, M. javanica, and M. hapla reproduced on Pinus ponderosa, while Xiphinema index, Aphelenchus avenae, Paratylenehus neoamblycephalus, Tylenchulus semipenetrans, and Macroposthonia xenoplax did not. P. vulnus, P. brachyurus, P. penetrans, A. avenae, D. destructor, T. semipenetrans, and P. neoamblycephalus significantly suppressed both the shoot and root wet weights of ponderosa pine seedlings obtained from stands in five different locations. X. index significantly suppressed root wet weights, M. xenoplax siguificantly suppressed shoot wet weight, and M. incognita, M. javanica, and M. hapla suppressed neither at the inoculation levels used. Injurious nematodes tended to suppress root growth more than shoot growth. Seedlings from two locations produced greater shoot growth wet weight than did seedlings from the other three locations. The more injurious nematodes tended to cause an increase in the water content of shoots. Frequency analyses of seedling population shoot-root ratios indicated that ponderosa pine seedlings could be selected for better shoot-root ratios as well as for resistance to several pathogenic nematodes. PMID:19300659

Eficácia da associação de cipermetrina, clorpirifós, butóxido de piperonila e fluazuron contra haematobia irritans em bovinos naturalmente infestados

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Diefrey Ribeiro Campos

2018-05-01

Full Text Available Haematobia irritans é uma mosca de grande importância na pecuária bovina. É responsável por causar estresse crônico ao rebanho causando desconforto e levando a redução da produção de carne e leite e depreciação do couro. Também são responsáveis por transmitir vírus, bactéria e facilitar ao desenvolvimento de míiases. O objetivo deste trabalho foi avaliar a eficácia de um produto ectoparasiticida contendo a associação de cipermetrina, clorpirifós, butóxido de pireronila e fluazuron na formulação “pour on” no controle da mosca H. irritans em bovinos naturalmente infestados. Foram utilizados 30 bovinos, mestiços, sem distinção de sexo ou idade. Todos os animais incluídos no estudo apresentaram pelo menos 50 moscas adultas de H. irritans de ocorrência natural. Os animais do grupo tratado foram medicados com a associação de cipermetrina (5mg/kg, clorpirifós (7mg/kg, butóxido de pireronila (5mg/kg e fluazuron (2,5mg/kg, na dose de 1ml para cada 10 quilos de peso vivo, pela via tópica (“pour on” em dose única. A eficácia mosquicida foi avaliada um, três, sete, 14 e 21 dias após o tratamento, a partir da contagem de moscas adultas sobre os animais dos dois os grupos. A eficácia da associação testada neste estudo foi de 98,65%; 96,69%; 92,01%; 87,79% e 76,43% nos dias +1, +3, +7, +14 e +21 respectivamente. A associação de cipermetrina, clorpirifós, butóxido de piperonila e fluazuron na formulação “pour on” é eficaz no controle de H. irritans em bovinos naturalmente infestados.

Nematicidal and larvicidal activities of the essential oils from aerial parts of Pectis oligocephala and Pectis apodocephala Baker

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Maria Rose Jane R. Albuquerque

2007-06-01

Full Text Available The chemical composition of the essential oils from aerial parts of Pectis apodocephala and Pectis oligocephala were analyzed by GC-MS. The essential oils of these species were predominantly constituted by monoterpenes. Geranial (42.9-44.5%, neral (32.2-34.2% and alpha-pinene (10.7-11.4% were the main constituents in the oil of P. apodocephala, while p-cymene (50.3-70.9% and thymol (24.4-44.7%, were the prevalent compounds in the oil of P. oligocephala. The essential oils were tested against the root knot nematode Meloidogyne incognita and Aedes aegypti larvae survival. The results obtained show that both essential oils exhibited significant activity and could be considered as potent natural namaticidal and larvicidal agents.A composição química dos óleos essenciais das partes aéreas de Pectis apodocephala e Pectis oligocephala foi analisada por CG-EM. Os óleos essenciais destas espécies foram predominantemente constituídos por monoterpenos. Geranial (42, 9-44, 5%, neral (32, 2-34, 2% e alfa-pineno (10, 7-11, 4% foram os constituintes majoritários no óleo de P. apodocephala, enquanto p-cimeno (50, 3-70, 9% e timol (24, 4-44, 7%, foram os compostos prevalentes no óleo de P. oligocephala. Ambos os óleos foram testados contra o nematóide Meloidogyne incognita e larvas do mosquito Aedes aegypti no terceiro estágio. Os resultados obtidos mostraram que os óleos exibem significante atividade e podem, portanto, ser considerados como potenciais agentes nematicida e larvicida naturais.

Factores asociados a la infección por Ehrlichia canis en perros infestados con garrapatas en la ciudad de Huánuco, Perú

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Edward Huerto-Medina

Full Text Available El objetivo del estudio fue determinar la frecuencia y factores asociados a la infección por Ehrlichia canis en perros. Se recolectaron muestras de sangre de 150 perros infestados con garrapatas en 10 consultorios veterinarios de la ciudad de Huánuco en Perú, los perros fueron seleccionados al azar sin distinción de raza, edad ni sexo. Se detectó anticuerpos contra Ehrlichia canis mediante inmunoensayo cromatográfico. El 51,3% de perros estuvieron infectados por Ehrlichia canis. En el análisis multivariado se encontraron asociados a la presencia Ehrlichia canis, el mal estado de salud del perro (p=0,049, un promedio mayor de infestación por garrapatas (p=0,018, perros de edad adulta (p=0,038. La frecuencia de Ehrlichia canis en perros de esta ciudad es alta. Se recomienda el control de la garrapata marrón del perro (Rhipicephalus sanguineus vector de la Ehrlichia canis

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

Science.gov (United States)

Wood, B. W.

2008-01-01

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

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

Science.gov (United States)

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

2014-08-01

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

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

NARCIS (Netherlands)

Beek, van der J.G.; Veldhuis, W.B.J.; ZijIstra, C.; Silfhout, van C.H.

1996-01-01

A procedure for long-term preservation of gennplasm of Meloidogyne hapla and M. chitwoodi in liquid nitrogen is described, including a pretrearrnenr with 10% ethanediol for 2 h at room temperature and 40 % ethanecliol for 45 min on ice. Survival rates ranged from 45 to 98 % with an average of 75 %.

Additional information on Meloidogyne inornata Lordello, 1956 (Tylenchida: Meloidogynidae) and its characterisation as a valid species

NARCIS (Netherlands)

Carneiro, R.M.D.G.; Lourdes Mendes, de M.; Almeida, M.R.A.; Santos, Dos M.F.A.; Gomes, A.C.M.M.; Karssen, G.

2008-01-01

A root-knot nematode parasitising yakon (Polymia sonchifolia) in São Paulo State, Brazil, is identified as Meloidogyne inornata. The species is redescribed from this material and compared with the original description of M. inornata. The female perineal patterns have a distinct, high, dorsal arch

Evidence for Reciprocal Selection between Populations of Meloidogyne arenaria and Pasteuria penetrans in a Field Study

Science.gov (United States)

Beginning in 1998, a bioassay using second-stage juveniles (J2) from a greenhouse (GH) population of Meloidogyne arenaria (Ma) was used to monitor endospore densities of the bacterium Pasteuria penetrans, which was parasitizing Ma in a crop rotation study. Spore densities of the bacterium were very...

Evaluation of steam for Meloidogyne Arenaria control in production of in-ground floriculture crops in Florida

Science.gov (United States)

Steam and soil solarization were investigated for control of the root-knot nematode Meloidogyne arenaria in two years of field trials on a commercial flower farm in Florida. The objective was to determine if pre-plant steam treatments in combination with solarization, or solarization alone effective...

Comparing root knot nematode (Meloidogyne spp.) effects on tomato (Solanum lycopersicum) and grapevine (Vitis spp.) metabolic profiles

Science.gov (United States)

Root knot nematodes (Meloidogyne spp., RKN) can negatively impact both herbaceous annual and woody perennial hosts. RKN infestations also may increase plant host susceptibility to other stresses such as those imposed by water deficits or various diseases. However, little is known about direct or ind...

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

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Ahmed Elhady

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

Velocidad y Tiempo de Centrifugación para Extraer Nematodos Fitoparásitos del Suelo.

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Volcy Charles

1980-09-01

Full Text Available An experiment was carried out in order to compare different combination of speeds and times of centrifugation to isolate Helicotylenchus dihystera, Meloidogyne incognita and Tylenchulus semipenetrans. The centrifugation-sugar screening method was used. Two loam soils were use with natural infestations of the above mentioned nematodes and a silty loam with natural infestation of H. dihystera. It was concluded that the combination with more consistent results to isolate the spiral eelworm was the centrifugation at 1000 rpm (200 g for 5 minutes in both cycles, while the combinations with best result to extract the other two species was the centrifugation at 2000 rpm (800 g for 3 minutes in both cycles.

Comparative genomic and functional analyses: unearthing the diversity and specificity of nematicidal factors in Pseudomonas putida strain 1A00316

Science.gov (United States)

Guo, Jing; Jing, Xueping; Peng, Wen-Lei; Nie, Qiyu; Zhai, Yile; Shao, Zongze; Zheng, Longyu; Cai, Minmin; Li, Guangyu; Zuo, Huaiyu; Zhang, Zhitao; Wang, Rui-Ru; Huang, Dian; Cheng, Wanli; Yu, Ziniu; Chen, Ling-Ling; Zhang, Jibin

2016-01-01

We isolated Pseudomonas putida (P. putida) strain 1A00316 from Antarctica. This bacterium has a high efficiency against Meloidogyne incognita (M. incognita) in vitro and under greenhouse conditions. The complete genome of P. putida 1A00316 was sequenced using PacBio single molecule real-time (SMRT) technology. A comparative genomic analysis of 16 Pseudomonas strains revealed that although P. putida 1A00316 belonged to P. putida, it was phenotypically more similar to nematicidal Pseudomonas fluorescens (P. fluorescens) strains. We characterized the diversity and specificity of nematicidal factors in P. putida 1A00316 with comparative genomics and functional analysis, and found that P. putida 1A00316 has diverse nematicidal factors including protein alkaline metalloproteinase AprA and two secondary metabolites, hydrogen cyanide and cyclo-(l-isoleucyl-l-proline). We show for the first time that cyclo-(l-isoleucyl-l-proline) exhibit nematicidal activity in P. putida. Interestingly, our study had not detected common nematicidal factors such as 2,4-diacetylphloroglucinol (2,4-DAPG) and pyrrolnitrin in P. putida 1A00316. The results of the present study reveal the diversity and specificity of nematicidal factors in P. putida strain 1A00316. PMID:27384076

Arbuscular mycorrhizal fungi affect both penetration and further life stage development of root-knot nematodes in tomato.

Science.gov (United States)

Vos, Christine; Geerinckx, Katleen; Mkandawire, Rachel; Panis, Bart; De Waele, Dirk; Elsen, Annemie

2012-02-01

The root-knot nematode Meloidogyne incognita poses a worldwide threat to agriculture, with an increasing demand for alternative control options since most common nematicides are being withdrawn due to environmental concerns. The biocontrol potential of arbuscular mycorrhizal fungi (AMF) against plant-parasitic nematodes has been demonstrated, but the modes of action remain to be unraveled. In this study, M. incognita penetration of second-stage juveniles at 4, 8 and 12 days after inoculation was compared in tomato roots (Solanum lycopersicum cv. Marmande) pre-colonized or not by the AMF Glomus mosseae. Further life stage development of the juveniles was also observed in both control and mycorrhizal roots at 12 days, 3 weeks and 4 weeks after inoculation by means of acid fuchsin staining. Penetration was significantly lower in mycorrhizal roots, with a reduction up to 32%. Significantly lower numbers of third- and fourth-stage juveniles and females accumulated in mycorrhizal roots, at a slower rate than in control roots. The results show for the first time that G. mosseae continuously suppresses root-knot nematodes throughout their entire early infection phase of root penetration and subsequent life stage development.

Management of Root-Nematode (Meloidogyne SPP)

International Nuclear Information System (INIS)

Miano, D.W

2002-01-01

Greenhouse and field experiments were undertaken to determine the possibility of using soil amendments with different C:N levels or applied at different rates and times in the control of root-knot nematodes (Meloidogyne spp.)in tomato c.v Cal J.A naturally infested field was used while artificial inoculation was done in the greenhouse. Root galling was rated on a scale of 0-10, nematode population was estimated by counting second stage juveniles extracted from 200 cm 3 soil and fruit yields were recorded at the end of the season. Nematode population densities and galling indices were significantly (P< or=0.05) lower in amended soils compared to the control. Application of the amendments also resulted in significant (P< or=0.05) increase in yields. Chicken manure, compost manure, neem products and pig manure were were the most effective amendments. Fresh chicken manure had a more suppressive effect on nematode than when the manure was decomposed within or outside a nematode infested field. A general decrease in juvenile populations and galling was observed with increase of organic amendments applied

Influence of root exudates and soil on attachment of Pasteuria penetrans to root-knot nematode Meloidogyne arenaria

Science.gov (United States)

Pasteuria penetrans is a parasite of root-knot nematode (Meloidogyne spp.). Spores of P. penetrans attach to the cuticle of second stage juvenile (J2) and sterilize infected female. This study looked at different factors that influence spore attachment of P. penetrans to M. arenaria. Incubating J2 ...

A Hypersensitivity-Like Response to Meloidogyne graminicola in Rice (Oryza sativa).

Science.gov (United States)

Phan, Ngan Thi; De Waele, Dirk; Lorieux, Mathias; Xiong, Lizhong; Bellafiore, Stephane

2018-04-01

Meloidogyne graminicola is a major plant-parasitic nematode affecting rice cultivation in Asia. Resistance to this nematode was found in the African rice genotypes Oryza glaberrima and O. longistaminata; however, due to interspecific hybrid sterility, the introgression of resistance genes in the widely consumed O. sativa varieties remains challenging. Recently, resistance was found in O. sativa and, here, we report for the first time the histological and genetic characterization of the resistance to M. graminicola in Zhonghua 11, an O. sativa variety. Bright-light microscopy and fluorescence observations of the root tissue of this variety revealed that the root cells surrounding the nematode displayed a hypersensitivity-like reaction with necrotic cells at early stages of infection when nematodes are migrating in the root's mesoderm. An accumulation of presumably phenolic compounds in the nematodes' neighboring root cells was also observed. In addition, at a later stage of infection, not only were few feeding sites observed but also the giant cells were underdeveloped, underlining an incompatible interaction. Furthermore, we generated a hybrid O. sativa population by crossing Zhonghua 11 with the susceptible O. sativa variety IR64 in order to describe the genetic background of this resistance. Our data suggested that the resistance to M. graminicola infection was qualitative rather than quantitative and, therefore, major resistance genes must be involved in this infection process. The full characterization of the defense mechanism and the preliminary study of the genetic inheritance of novel sources of resistance to Meloidogyne spp. in rice constitute a major step toward their use in crop breeding.

Caracterización de daños producidos por Meloidogyne Spp. (Nemata: Tylenchida en la vid en Mendoza, Argentina

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Carla Vanina Dagatti

2014-12-01

Full Text Available El objetivo de esta investigación fue comparar y establecer relaciones entre los diferentes indicadores de crecimiento entre plantas de vid con dos niveles de infestación (alto y leve de Meloidogyne spp. El estudio se realizó en un viñedo cv Merlot, situado en Agrelo, Mendoza, donde se escogieron 2 parcelas, con y sin nematodos, con diferentes niveles de crecimiento vegetativo. Los indicadores a evaluar fueron: peso y número de racimos por planta, peso de poda, cantidad de entrenudos y área foliar de hojas y feminelas. El grado de infestación de nematodos de cada parcela se determinó mediante la técnica flotación - centrifugación. Para el análisis estadístico se utilizó la prueba de wilcoxon (Mann Whitney U y el test de student. Además, mediante un análisis de regresión lineal, se comprobó si existía relación entre los indicadores evaluados y la densidad de población de Meloidogyne spp. expresado en número de estados juveniles (J2 presentes en el suelo. Los resultados indicaron que la parcela con menor densidad poblacional de juveniles de Meloidogyne spp., presentó mayor peso promedio de madera de poda, así como también un área foliar de hojas y feminelas superior. Con respecto al peso promedio de racimos por planta, dicha parcela también superó a aquella con alta concentración de nematodos.

Evaluación nematicida del aceite esencial de Tagetes zypaquirensis en el manejo del nematodo Meloidogyne spp.

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David Eduardo Álvarez

2016-06-01

Full Text Available El lulo (Solanum quitoense Lam. es un frutal andino de gran importancia económica en Colombia, sin embargo, las áreas sembradas y rendimientos han sufrido una evidente reducción debido al ataque de patógenos como el nematodo Meloidogyne spp., que ha ocasionado pérdidas de hasta 50%. En la naturaleza existen diferentes recursos vegetales con propiedades nematicidas, destacándose al género Tagetes. El objetivo de esta investigación fue evaluar la actividad nematicida del aceite esencial de Tagetes zypaquirensis sobre Meloidogyne spp. Bajo condiciones de invernadero se evaluaron cuatro concentraciones del aceite esencial (100, 200, 400, 800mg/kg de suelo las cuales fueron aplicadas a un suelo con juveniles de segundo estadio del nematodo +400 J2/100g. Además, se establecieron tres comparadores: un tratamiento sin aplicación de aceite esencial, un suelo sin nematodo y un suelo tratado con i.a carbofuran (33,2% bajo una dosis de 2cc/L. Para cada tratamiento, las variables a evaluar fueron: severidad, altura de planta, peso fresco y seco al aire, peso fresco radical, número de huevos del nematodo/100g raíz y número de J2/100g de suelo. Los componentes mayoritarios del aceite esencial de T. zypaquirensis fueron dihidrotagetona y E-tagetona con una proporción relativa de 42,2 y 22,9%, respectivamente. Los resultados indicaron, que la concentración 800mg/kg de aceite esencial presentó la misma acción nematicida que el suelo tratado con carbofuran al reducir las poblaciones de Meloidogyne spp. y presentar valores similares en las variables fitométricas. Se concluye que el aceite esencial T. zypaquirensis puede ser una alternativa para el manejo de la enfermedad del nudo radical.

Meloidogyne luci n. sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitising different crops in Brazil, Chile and Iran

NARCIS (Netherlands)

Carneiro, R.M.D.G.; Correa, V.R.; Almeida, M.R.A.; Gomes, A.C.M.M.; Deimi, A.M.; Castagnone-Sereno, P.; Karssen, G.

2014-01-01

A new root-knot nematode parasitising vegetables, flowers and fruits in Brazil, Iran and Chile, is described as Meloidogyne luci n. sp. The female has an oval to squarish perineal pattern with a low to moderately high dorsal arc and without shoulders, similar to M. ethiopica. The female stylet is

CONTROLE DE MELOIDOGYNE JAVANICA COM PASTEURIA PENETRANS CONTROL OF MELOIDOGYNE JAVANICA BY PASTEURIA PENETRANS

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RAVI DATT SHARMA

1999-11-01

Full Text Available Objetivou-se, com esse trabalho, avaliar a eficiência de Pasteuria penetrans no controle de Meloidogyne javanica em condições de casa de vegetação. Os tratamentos eram compostos de quatro níveis de inóculo de P. penetrans, 0, 10x10(5, 50x10(5 e 100x10(5 endósporos/kg de solo autoclavado. Imediatamente após a inoculação da bactéria P. penetrans no solo autoclavado, 1.000 juvenis de segundo estádio de M. javanica foram inoculados em cada vaso. Quarenta e oito horas após a inoculação do nematóide, uma plântula de soja cv. FT-Cristalina, com três dias de idade, foi transplantada para cada vaso. O experimento foi avaliado em duas etapas: a primeira, 89 dias após o transplantio da soja, e a segunda, 90 dias após um segundo(plantio de soja, em seqüência a um pousio de 30 dias. Na primeira avaliação, o maior peso da matéria fresca da planta foi obtido no tratamento com 100x10(5 endósporos/kg de solo, o que diferiu significativamente (PIn a greenhouse experiment, the efficiency of Pasteuria penetrans against Meloidogyne javanica was evaluated on soybean cv. FT-Cristalina using four inoculum levels of P. penetrans viz: 0, 10x10(5, 50x10(5 and 100x10(5 endospores/kg of soil. Immediately after inoculating the autoclaved soil with P. penetrans, 1,000 second-stage juveniles were inoculated in each pot. After 48 hours of nematode inoculation, a 3-day old soybean seedling was transplanted in each pot. The experiment was evaluated in two steps of which the first evaluation was made after 89 days of transplanting the seedlings; and the second after 90 days of soybean sowing in sequence with a following period of 30 days. In the first evaluation, the highest fresh plant weight was observed in treatment with 100x10(5 endospores/kg of soil which differed significantly (P<0.05 from other treatments except the untreated control. The maximum increase in fresh pod weight of treatment with 100x10(5 endospores/kg of soil differed significantly

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

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Woo Jong Ha

2014-06-01

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

Characterization of Thermo- and Detergent Stable Antigenic Glycosylated Cysteine Protease of Euphorbia nivulia Buch.-Ham. and Evaluation of Its Ecofriendly Applications

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Shamkant B. Badgujar

2013-01-01

Full Text Available An antigenic glycosylated cysteine protease has been purified from the latex of Euphorbia nivulia Buch.-Ham. It exhibits remarkable protease activity in the presence of metal ions, oxidizing agents, organic solvents, and detergents. This enzyme showed potential role in leather processing industry due to its dehairing activity for animal hide without hydrolyzing fibrous proteins, producing, by this way, a better quality product. The enzyme can also be used for silver recovering from X-ray plates. In addition, the stability (temperature and surfactants and hydrolysis of blood stain data also revealed its application in detergent industries. Agriculturally, this protease finds application in biocontrol process against the infectious management of root knot nematode, Meloidogyne incognita. Biologically, it shows noticeable wound healing, haemostatic and antibacterial activity.

Characteristics and Efficacy of a Sterile Hyphomycete (ARF18), a New Biocontrol Agent for Heterodera glycines and Other Nematodes

Science.gov (United States)

Kim, D. G.; Riggs, R. D.

1991-01-01

A filamentous, nonsporulating fungus, designated Arkansas Fungus 18 (ARF18), was isolated from 9 of 95 populations of Heterodera glycines, the soybean cyst nematode, in Arkansas. In petri dishes, ARF18 parasitized 89% of H. glycines eggs in cysts. The fungus also infected eggs of Meloidogyne incognita and eggs in cysts of Cactodera betulae, H. graminophila, H. lespedezae, H. leuceilyma, H. schachtii, and H. trifolii. In pot tests, reproduction of SCN was 70% less in untreated field soil that was naturally infested by ARF18 than in autoclaved field soil. Although ARF18 grew well at 25 C on cornmeal agar over a wide pH range, it did not sporulate on 28 media and thus could not be identified to genus or species. PMID:19283127

Characteristics and Efficacy of a Sterile Hyphomycete (ARF18), a New Biocontrol Agent for Heterodera glycines and Other Nematodes.

Science.gov (United States)

Kim, D G; Riggs, R D

1991-07-01

A filamentous, nonsporulating fungus, designated Arkansas Fungus 18 (ARF18), was isolated from 9 of 95 populations of Heterodera glycines, the soybean cyst nematode, in Arkansas. In petri dishes, ARF18 parasitized 89% of H. glycines eggs in cysts. The fungus also infected eggs of Meloidogyne incognita and eggs in cysts of Cactodera betulae, H. graminophila, H. lespedezae, H. leuceilyma, H. schachtii, and H. trifolii. In pot tests, reproduction of SCN was 70% less in untreated field soil that was naturally infested by ARF18 than in autoclaved field soil. Although ARF18 grew well at 25 C on cornmeal agar over a wide pH range, it did not sporulate on 28 media and thus could not be identified to genus or species.

A field study on the host status of different crops for Meloidogyne minor and its damage potential to potato

NARCIS (Netherlands)

Thoden, T.C.; Korthals, G.W.; Visser, J.H.M.; Gastel-Topper, van A.W.W.

2012-01-01

For several years, a new species of root-knot nematode, Meloidogyne minor, has been reported from parts of The Netherlands, Belgium, UK and Ireland. So far, this species causes most problems on golf courses but has also been reported from a potato field in Zeijerveld (The Netherlands) where it

Biological Control of Meloidogyne javanica on Tomato by Trichoderma harzianum BI and Salicylic Acid

OpenAIRE

, F. Naserinasab; , N. Sahebani; , H.R. Etebarian

2016-01-01

In this study, Trichoderma harzianum BI was evaluated for its capacity to reduce the incidence and pathogenicity of the root-knot nematode Meloidogyne javanica on tomato. Culture Şltrates of T. harzianum BI at different concentrations, (standard, 1:1, 1:10, and 1:100) were studied. In vitro studies revealed that hatching of M. javanica eggs was inhibited by the culture Şltrates and this inhibition was positively correlated with increase in the concentration of culture Şltrates. Parasitism of ...

Host status of six major weeds to Meloidogyne chitwoodi and Pratylenchus penetrans, including a preliminary field survey concerning other weeds

NARCIS (Netherlands)

Kutywayo, V.; Been, T.H.

2006-01-01

A glasshouse experiment was carried out to investigate the host status of six important weeds in intensive agricultural cropping systems to Meloidogyne chitwoodi and Pratylenchus penetrans. Senecio vulgaris L., Capsella bursa-pastoris (L.) Medic. and Solanum nigrum L. were hosts of M. chitwoodi with

Description of Meloidogyne minor n.sp. (Nematoda: Meloidogynidae), a root-knot nematode associated with yellow patch disease in golf courses

NARCIS (Netherlands)

Karssen, G.; Bolk, R.J.; Aelst, van A.C.; Beld, van den I.; Kox, L.F.F.; Korthals, G.W.; Molendijk, L.P.G.; Zijlstra, C.; Hoof, van R.A.; Cook, R.

2004-01-01

A relatively small root-knot nematode, Meloidogyne minor n. sp., is described and illustrated from tomato from the Netherlands. This new species is characterised by the following features: female with dorsally curved stylet, 14 Pm long, with transversely ovoid knobs slightly sloping backwards from

Population Development of Pasteuria penetrans on Meloidogyne arenaria.

Science.gov (United States)

Oostendorp, M; Dickson, D W; Mitchell, D J

1991-01-01

A microplot study on the influence of cropping sequences with peanut in summer and bare fallowed or cover crops of rye or vetch in winter on the population development of Pasteuria penetrans was initiated in the spring of 1987. The number of spores of P. penetrans attached per second-stage juvenile of Meloidogyne arenaria race 1 increased from 0.11 in the fall of 1987 to 7.6, 8.6, and 3.6 in the fall of 1989 in the rye, vetch, and fallowed plots, respectively. Higher (P rye and vetch plots than in fallowed plots. No influence of P. penetrans on peanut, rye, or vetch yield was observed in 1987 and 1988, but in 1989 peanut yield was 64% higher (P cropping sequences in the spring of 1988 and 1989 but not in the fall following the peanut crop. In the spring the plots with rye had the lowest nematode numbers in either year (P rye, vetch, and fallowed).

El género Meloidogyne y su situación con respecto a la agricultura en la Argentina

OpenAIRE

Doucet, Marcelo E.; Lax, Paola

2007-01-01

El género Meloidogyne comprende varias especies, algunas de las cuales ocasionan severos daños a numerosos cultivos pudiendo afectar seriamente su producción. En este trabajo se presenta una síntesis de los principales aspectos relacionados con este nematodo en el país. Academia Nacional de Agronomía y Veterinaria

Isolation and characterization of a rhizobacterial antagonist of root-knot nematodes.

Science.gov (United States)

Wei, Lihui; Shao, Ying; Wan, Jingwang; Feng, Hui; Zhu, Hua; Huang, Huiwen; Zhou, Yijun

2014-01-01

The rhizobacterial strain Jdm2 was isolated from the rhizosphere of the traditional Chinese medicinal herb Trichosanthes kirilowii in Jiangsu province, China, and was identified as Bacillus subtilis. Exposure of cell-free filtrate of the strain to the root-knot nematode Meloidogyne incognita under in vitro conditions caused substantial mortality of the second stage juvenile (J2) and significantly reduced egg hatchability. A greenhouse trial demonstrated that 56 days after treatment with Jdm2, the number of galls associated with M. incognita infection in the tomato (Solanum lycopersicum) roots was significantly reduced compared to controls, and the disease severity of infected plants was lower in treated plants (36%) compared to water control (75%). Consistently, in the field trial, the biocontrol efficacy of Jdm2 reached 69%, 51% and 48% after 30, 60 and 90 days post-transplantation, respectively. As indicated by PCR-DGGE analysis, inoculation with Jdm2 strain had an effect on the bacterial community of the tomato rhizosphere at the first stage, but was not able to imperil the bacterial community stability for long time. The novel bacterial strain Jdm2 enhances plant growth and inhibits nematode activity, and has the potential to be a safe and effective microbial pesticide.

Isolation and characterization of a rhizobacterial antagonist of root-knot nematodes.

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Lihui Wei

Full Text Available The rhizobacterial strain Jdm2 was isolated from the rhizosphere of the traditional Chinese medicinal herb Trichosanthes kirilowii in Jiangsu province, China, and was identified as Bacillus subtilis. Exposure of cell-free filtrate of the strain to the root-knot nematode Meloidogyne incognita under in vitro conditions caused substantial mortality of the second stage juvenile (J2 and significantly reduced egg hatchability. A greenhouse trial demonstrated that 56 days after treatment with Jdm2, the number of galls associated with M. incognita infection in the tomato (Solanum lycopersicum roots was significantly reduced compared to controls, and the disease severity of infected plants was lower in treated plants (36% compared to water control (75%. Consistently, in the field trial, the biocontrol efficacy of Jdm2 reached 69%, 51% and 48% after 30, 60 and 90 days post-transplantation, respectively. As indicated by PCR-DGGE analysis, inoculation with Jdm2 strain had an effect on the bacterial community of the tomato rhizosphere at the first stage, but was not able to imperil the bacterial community stability for long time. The novel bacterial strain Jdm2 enhances plant growth and inhibits nematode activity, and has the potential to be a safe and effective microbial pesticide.

A novel serine protease, Sep1, from Bacillus firmus DS-1 has nematicidal activity and degrades multiple intestinal-associated nematode proteins.

Science.gov (United States)

Geng, Ce; Nie, Xiangtao; Tang, Zhichao; Zhang, Yuyang; Lin, Jian; Sun, Ming; Peng, Donghai

2016-04-27

Plant-parasitic nematodes (PPNs) cause serious harm to agricultural production. Bacillus firmus shows excellent control of PPNs and has been produced as a commercial nematicide. However, its nematicidal factors and mechanisms are still unknown. In this study, we showed that B. firmus strain DS-1 has high toxicity against Meloidogyne incognita and soybean cyst nematode. We sequenced the whole genome of DS-1 and identified multiple potential virulence factors. We then focused on a peptidase S8 superfamily protein called Sep1 and demonstrated that it had toxicity against the nematodes Caenorhabditis elegans and M. incognita. The Sep1 protein exhibited serine protease activity and degraded the intestinal tissues of nematodes. Thus, the Sep1 protease of B. firmus is a novel biocontrol factor with activity against a root-knot nematode. We then used C. elegans as a model to elucidate the nematicidal mechanism of Sep1, and the results showed that Sep1 could degrade multiple intestinal and cuticle-associated proteins and destroyed host physical barriers. The knowledge gained in our study will lead to a better understanding of the mechanisms of B. firmus against PPNs and will aid in the development of novel bio-agents with increased efficacy for controlling PPNs.

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

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Mohammed Ahmed

2013-12-01

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

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

NARCIS (Netherlands)

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

2017-01-01

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

Penetration and post-infection development of root-knot nematodes in watermelon

Energy Technology Data Exchange (ETDEWEB)

López-Gómez, M.; Verdejo-Lucas, S.

2017-07-01

Meloidogyne javanica has showed less reproductive success than M. incognita in watermelon genotypes. This study was conducted to elucidate the low reproduction of M. javanica in watermelon. The post-infection development of M. javanica in watermelon ‘Sugar Baby’ was determined at progressively higher initial population (Pi) levels at two time points during the life cycle. Plants were inoculated with 0, 25, 50, 100, 200, and 300 second-stage juveniles (J2)/plant. The increase in Pi was correlated with the penetration rates (R2= 0.603, p<0.001) and total numbers of nematodes in the root (R2 =0.963, p< 0.001) but there was no correlation between the Pi and the reproduction factor (eggs/plant/Pi). The population in the roots at 26 days post-inoculation (dpi) consisted primarily of third-stage juveniles (J3) with a small presence of J2 and fourth stages, and egg-laying females. The dominance of the J3, when egg-laying females are expected, point to the malfunction of the feeding sites that failed to support nematode development beyond the J3 stage. The similarities in egg-laying females at 26 and 60 dpi imply the disruption of the life cycle. Watermelon compensated for M. javanica parasitism by increasing vine length (19% to 33%) and dry top weight (40%) in comparison with the non-inoculated plants. The area under the vine length progress curve was significantly larger as the Pi progressively increased (R²=0.417, p<0.001). Physiological variation was detected between the M. incognita populations. M. arenaria had less ability to invade watermelon roots than did M. incognita and M. javanica.

Long-term in vitro system for maintenance and amplification of root-knot nematodes in Cucumis sativus roots

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Fernando E. eDíaz-Manzano

2016-02-01

Full Text Available Root-knot nematodes (RKN are polyphagous plant-parasitic roundworms that produce large crop losses, representing a relevant agricultural pest worldwide. After infection, they induce swollen root structures called galls containing giant cells (GCs indispensable for nematode development. Among efficient control methods are biotechnology-based strategies that require a deep knowledge of underlying molecular processes during the plant-nematode interaction. Methods of achieving this knowledge include the application of molecular biology techniques such as transcriptomics (massive sequencing or microarray hybridization, proteomics or metabolomics. These require aseptic experimental conditions, as undetected contamination with other microorganisms could compromise the interpretation of the results. Herein, we present a simple, efficient and long-term method for nematode amplification on cucumber roots grown in vitro. Amplification of juveniles (J2 from the starting inoculum is around 40-fold. The method was validated for three Meloidogyne species (M. javanica, M. incognita and M. arenaria, producing viable and robust freshly hatched J2s. These can be used for further in vitro infection of different plant species such as Arabidopsis, tobacco and tomato, as well as enough J2s to maintain the population. The method allowed maintenance of around 90 Meloidogyne spp. generations (one every two months from a single initial female over 15 years.

Physiological changes in leaves of mungbean plants infected with Meloidogyne javanica

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N. Ahmed

2009-09-01

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

Effect of the foliage of Tagetes minutaon Meloidogyne incognitaroot-galling on Capsicum annuumin a greenhouse

OpenAIRE

Murga-Gutiérrez, Santos Nélida; Alvarado-Ibáñez, Juan Carlos; Vera-Obando, Nora Yessenia

2013-01-01

Se investigó el efecto del follaje del “huacatay” Tagetes minutasobre la nodulación radicular producida por el nematodo Meloidogyne incognitaque parasita el “pimiento páprika” Capsicum annuumcultivado en invernadero, con la finalidad de obtener una alternativa de control de este nematodo. Se utilizaron tres grupos experimentales y un testigo, con 12 macetas cada uno, las cuales contenían suelo y arena estériles (1:1). A este substrato se adicionó el follaje de T. minutaal 20, 35 y 50% (v/...

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

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Daniel Rufino Amaral

2009-01-01

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

Nematicidal natural products from the aerial parts of Buddleja crispa.

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Sultana, Nighat; Akhter, Musarrat; Khan, Rashid Ali; Afza, Nighat; Tareen, Rasool Bakh; Malik, Abdul

2010-05-01

Studies on the aerial parts of Buddleja crispa yielded 13 known compounds, nonyl benzoate, hexyl p-hydroxy-cinnamate, ginipin, gardiol, 1-heptacosanol, steroidal galactoside (22 R)-stigmasta-7,9 (11)-dien-22 beta-ol-3beta-O-beta-D-galactopyranoside, 3-methoxy benzoic acid, beta-sitosterol and ursolic acid. Besides this two iridoid galactosides buddlejosides A, buddlejosides B and a benzofuran-type sesquiterpene buddlejone have been isolated from the ETOAC fraction of B. crispa. Together with the above compounds, methyl benzoate (1) and 3-methoxy-4-hydroxy benzoic acid (2) were also isolated. Compound 2 (C(8)H(8)O(4)) was identified by comparison of its data with those reported earlier, which was originally isolated from Onosma hispidum, and this is the first report of its isolation from this species. For compounds 1 and 2, the total alcoholic soluble extract, methanol soluble, chloroform soluble, ethyl acetate soluble and petroleum ether soluble extract of the aerial parts of B. crispa were screened for nematicidal activity against nematodes of freshly hatched second-stage juveniles of Meloidogyne incognita (root-knot nematode), exhibiting 92%, 40%, 88%, 83%, 82% and 50% mortality, respectively, of eloids M. incognita at 0.5% concentration. Compound 1 was more potent than the nematicide Azadirachta indica at the same concentration. Negative results were obtained for the nematicidal activity of petroleum ether extract of B. crispa leaves.

Biocontrol Effectiveness of Indigenous Trichoderma Species against Meloidogyne javanica and Fusarium oxysporum f. sp. radicis lycopersici on Tomato

OpenAIRE

Hajji Lobna; Chattaoui Mayssa; Regaieg Hajer; M'Hamdi-Boughalleb Naima; Rhouma Ali; Horrigue-Raouani Najet

2016-01-01

In this study, three local isolates of Trichoderma (Tr1: T. viride, Tr2: T. harzianum and Tr3: T. asperellum) were isolated and evaluated for their biocontrol effectiveness under in vitro conditions and in greenhouse. In vitro bioassay revealed a biopotential control against Fusarium oxysporum f. sp. radicis lycopersici and Meloidogyne javanica (RKN) separately. All species of Trichoderma exhibited biocontrol performance and (Tr1) Trichoderma viride was the most efficient. In fact, growth rat...

Grafting guava on cattley guava resistant to Meloidogyne enterolobii

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Renata Rodrigues Robaina

2015-09-01

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

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

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Al-Hazmi, A S; Sasser, J N

1982-04-01

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

Identification of widely varying levels of resistance to meloidogyne incognita in sweet sorghum

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Sweet sorghum (Sorghum bicolor) is a potential bioenergy crop that could be incorporated into annual cropping systems in the southern US, where it would likely be rotated with cotton. The desirability of including sweet sorghum in a cotton cropping system will be influenced by sweet sorghum’s host ...

de papa en Costa Rica

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Zeidy Montero

2007-01-01

Full Text Available Especies del género Meloidogyne causan importantes daños al cultivo de la papa (Solanum tuberosum L alrededor del mundo. Su efecto puede ser directo al disminuir el rendimiento o indirecto al infectar los tubérculos y causar agallas o protuberancias, que les confiere una apariencia verrugosa, que afecta su calidad y reduce su valor comercial. En Capellades y Llano Grande de Cartago, Costa Rica, fueron encontrados tubérculos de papa, de la variedad Floresta y del clon Bananito, con numerosas protuberancias en su superficie. De las protuberancias se extrajo hembras ovígeras de Meloidogyne spp. Estudios morfológicos (diseño perineal de las hembras y moleculares (PCR y PCRRFLP mostraron que las hembras extraídas de las protuberancias pertenecen a la especie M. incognita. Se recomienda estudiar las causas que promueven la infección de los tubérculos en ambas localidades, ya que cerca del 90% del área cultivada de papa en el país corresponde a la variedad Floresta. En adición, se debe prestar especial atención a las zonas semilleristas, ya que los tubérculos-semilla podrían servir como fuente de inóculo y contribuir a la diseminación del patógeno a otras áreas.

Influence of Root Exudates and Soil on Attachment of Pasteuria penetrans to Meloidogyne arenaria.

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Liu, Chang; Timper, Patricia; Ji, Pingsheng; Mekete, Tesfamariam; Joseph, Soumi

2017-09-01

The bacterium Pasteuria penetrans is a parasite of root-knot nematodes ( Meloidogyne spp.). Endospores of P. penetrans attach to the cuticle of second-stage juveniles (J2) and subsequently sterilize infected females. When encumbered by large numbers of spores, juveniles are less mobile and their ability to infect roots is reduced. This study looked at different factors that influence spore attachment of P. penetrans to the root-knot nematode Meloidogyne arenaria . Pretreatment of J2 with root exudates of eggplant ( Solanum melongena cv. Black beauty) reduced spore attachment compared with pretreatment with phosphate-buffered saline (PBS), suggesting that the nematode surface coat was altered or the spore recognition domains on the nematode surface were blocked. Spore attachment was equally reduced following exposure to root exudates from both host and nonhost plants for M. arenaria , indicating a common signal that affects spore attachment. Although phytohormones have been shown to influence the lipophilicity of the nematode surface coat, auxins and kinetins did not affect spore attachment compared with PBS. Root exudates reduced spore attachment more in sterilized soil than in natural soil. Sterilization may have eliminated microbes that consume root exudates, or altered the chemical components of the soil solution or root exudates. Root exudates caused a greater decrease in spore attachment in loamy sand than in a sandy loam soil. The sandy loam had higher clay content than the loamy sand, which may have resulted in more adsorption of compounds in the root exudates that affect spore attachment. The components of the root exudates could have also been modified by soil type. The results of this study demonstrate that root exudates can decrease the attachment of P. penetrans endospores to root-knot nematodes, indicating that when these nematodes enter the root zone their susceptibility to spore attachment may decrease.

Etude de trois souches d'Arthrobotrys oligospora : Caractérisation biologique et effets sur Meloidogyne mayaguensis parasite de la tomate au Sénégal

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Gueyei, M.

1997-01-01

Full Text Available Etude de trois souches d'Arthrobotrys oligospora : Caractérisation biologique et effets sur Meloidogyne mayaguensis parasite de la tomate au Sénégal. Three strains (ORS 18690 S2, ORS 18691 S6 and ORS 18693 S5 of the nematophagous fungus Arthrobotrys oligospora have been isolated in Senegal for the first time. In vitro, two strains (ORS 18690 S2 and ORS 18693 S5 of them trapped 100 % and the other (ORS 18691 S5 80 %> of 7-day-old juvenile Meloidogyne mayaguensis within 48h. Optimal growth occured at 25-30°C and at a pH 5.6, but salinity inhibited development. In order to test the ability of fungi to control M. mayaguensis in pots on tomato, the fungus was incorporated into compost blocks or in vermiculite before sowing or subsequent transplanting. In pot experiments both strains reduced nematode populations ans stimulated seedling growth. However, these effects were higher in compost blocks than in vermiculite.

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

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Wiwin Setiawati

2013-05-01

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

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

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Bernardo Eduardo Roberto de Almeida

2003-01-01

Full Text Available Este trabalho foi realizado com o objetivo de efetuar um levantamento da ocorrência de Meloidogyne exigua em seringueira em São José do Rio Claro, MT. Foram amostradas 191 propriedades agrícolas, totalizando cerca de 18.000ha. Os nematóides foram identificados no Laboratório de Nematologia do Departamento de Fitossanidade da FCAV/UNESP, em Jaboticabal, SP. Foram encontrados níveis populacionais de M. exigua entre 0 e 61.824 juvenis/5g de raízes.

Karakterisasi Parsial Streptomyces spp., Agens Pengendali Hayati Peyakit Lincat Tembakau

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Triwidodo Arwiyanto

2007-12-01

Full Text Available Local isolates of Streptomyces spp. were proven could suppress "lincat disease" of tobacco in the field. Six isolates were chosen for partial characterization of their bacteriological properties as based for the next experiments purposes. The results indicated that the isolates produce miselium with spore chains, gram positive, aerob, catalase and oxidase positive. The isolates also hydrolize starch, gelatine and esculine; produce lecithinase enzyme, reduce nitrate to nitrite, do not produce melanine pigment, did not produce hydrogen sulfide. The isolates were sensitive against streptomycine and rifampicin; able to use several carbon and nitrogen sources tested. Capable to grow on several medium pH, from 4,3 to 8,0. The isolates were able to grow from 5° C to 45° C; able to grow on medium containing 4% to 7% NaCl and ion the medium containing 0,1% of phenol. Plant pathogenicity test result showed negative responses which indicated that the used isolates were non plant pathogenic. The ability in suppressing lincat pathogen (Ralstonia solanacearum and Meloidogyne incognita in vitro was vary between isolates.   Streptomyces spp, isolat lokal terbukti dapat menekan penyakit lunvat tembakau di lapangan. Sebanyak enam isolat dipilih untuk dicirikan sebagai sifat-sifat bakteriologinya sehingga dapat digunakan sebagai dasar dalam penelitian berikutnya. Penelitian dilakukan terhadap sifat morfologi, fisiologi dan sifat biokimia. Hasil penelitian menunjukkan bahwa isolat yang diteliti menghasilkan miselium yang memproduksi rangkaian spora, Gram positif, aerob, katalase dan oksidase positif. Isolat-isolat tersebut menghidrolisis pati, gelatin, eskulin; membentuk ensim lechitinase, mereduksi nitrat menjadi nitrit, tidak menghasilkan pigmen melanin, tidak membentuk hidrogen sulfida. Isolat yang diteliti peka terhadap antibiotik streptomisin dan nifampisin; mampu menggunakan beberapa sumber karbon dan sumber nitrogen yang diujikan, Kisaran pH untuk

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

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Mayer Newton Alex

2003-01-01

Full Text Available Um amplo projeto de estudos sobre a utilização do umezeiro como porta-enxerto para pessegueiro está sendo desenvolvido na FCAV/UNESP, Câmpus de Jaboticabal-SP, devido, especialmente, às promissoras características para uso como redutor de vigor da copa e sua boa qualidade de frutos. Alguns trabalhos na literatura citam o umezeiro como resistente ao nematóide das galhas, entretanto dispõe-se de poucas informações. Neste trabalho, teve-se por objetivo estudar a reação de clones de umezeiro e cultivares de pessegueiro a Meloidogyne javanica. O experimento foi conduzido em casa de vegetação, com 6 tratamentos (Clones 05; 10 e 15 de umezeiro e as cultivares Okinawa, Aurora-1 e Dourado-1 de pessegueiro e 9 repetições. As plantas foram mantidas em vasos de cerâmica contendo uma mistura de solo e areia (1:1, v/v, previamente autoclavada a 121ºC e 1kgf.cm-2 por 2 horas. Aos sessenta dias após o plantio, cada planta foi inoculada com 3.000 ovos e juvenis de segundo estádio de Meloidogyne javanica. Aos 100 dias após a inoculação, as plantas foram colhidas para avaliação da massa de matéria fresca do sistema radicular, número de galhas por sistema radicular, número de ovos e juvenis por 10 g de raízes, número de ovos e juvenis por sistema radicular e fator de reprodução. Verificou-se que todos os clones e cultivares de umezeiro e pessegueiro, respectivamente, mostraram-se resistentes a Meloidogyne javanica.

Observações sôbre a resistência de algumas variedades de soja ao nematóide das galhas

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J. Gomes da Silva

1952-03-01

Full Text Available Soybean varieties cultivated at present in Brazil (Abura and Rio Grande, as well as some other promissing strains (455, Chosen, Georgian, Pereira Barreto, Arksoy, Acadian, etc. have shown severe attacks by the rootknot nematodes. The study of the parasite showed that two forms are present, attacking the soybean roots, both being closely related to Meloidogyne incognita (Kofoid & White, 1919 Chitwood, 1949. Variety N 46-2652, considered to be resistent in the Southern part of the United States, proved to be susceptible to the mentioned nematodes, according to results of two pot test, discussed in this paper. Palmeto, La 41-1219, N 45-3799 and Otootan varieties were considered resistent to these nematodes, judged by the results of one field trial here reported. The resistence of varieties Palmeto and La 41-1219 was also confirmed by two pot experiments in which artificial infestation by nematodes was produced.

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

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Mauricio Batista Fialho

2012-06-01

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

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

Science.gov (United States)

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

2016-06-01

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

Rapid, simple and direct detection of Meloidogyne hapla from infected root galls using loop-mediated isothermal amplification combined with FTA technology.

Science.gov (United States)

Peng, Huan; Long, Haibo; Huang, Wenkun; Liu, Jing; Cui, Jiangkuan; Kong, Lingan; Hu, Xianqi; Gu, Jianfeng; Peng, Deliang

2017-04-03

The northern root-knot nematode (Meloidogyne hapla) is a damaging nematode that has caused serious economic losses worldwide. In the present study, a sensitive, simple and rapid method was developed for detection of M. hapla in infested plant roots by combining a Flinders Technology Associates (FTA) card with loop-mediated isothermal amplification (LAMP). The specific primers of LAMP were designed based on the distinction of internal transcribed spacer (ITS) sequences between M. hapla and other Meloidogyne spp. The LAMP assay can detect nematode genomic DNA at concentrations low to 1/200 000, which is 100 times more sensitive than conventional PCR. The LAMP was able to highly specifically distinguish M. hapla from other closely related nematode species. Furthermore, the advantages of the FTA-LAMP assay to detect M. hapla were demonstrated by assaying infected root galls that were artificially inoculated. In addition, M. hapla was successfully detected from six of forty-two field samples using FTA-LAMP technology. This study was the first to provide a simple diagnostic assay for M. hapla using the LAMP assay combined with FTA technology. In conclusion, the new FTA-LAMP assay has the potential for diagnosing infestation in the field and managing the pathogen M. hapla.

Rapid, simple and direct detection of Meloidogyne hapla from infected root galls using loop-mediated isothermal amplification combined with FTA technology

OpenAIRE

Peng, Huan; Long, Haibo; Huang, Wenkun; Liu, Jing; Cui, Jiangkuan; Kong, Lingan; Hu, Xianqi; Gu, Jianfeng; Peng, Deliang

2017-01-01

The northern root-knot nematode (Meloidogyne hapla) is a damaging nematode that has caused serious economic losses worldwide. In the present study, a sensitive, simple and rapid method was developed for detection of M. hapla in infested plant roots by combining a Flinders Technology Associates (FTA) card with loop-mediated isothermal amplification (LAMP). The specific primers of LAMP were designed based on the distinction of internal transcribed spacer (ITS) sequences between M. hapla and oth...

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

International Nuclear Information System (INIS)

Tariq, M.; Dawar, S.

2015-01-01

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

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

Science.gov (United States)

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

Characterization of isolates of meloidogyne from rice-wheat production fields in Nepal.

Science.gov (United States)

Pokharel, Ramesh R; Abawi, George S; Zhang, Ning; Duxbury, John M; Smart, Christine D

2007-09-01

Thirty-three isolates of root-knot nematode were recovered from soil samples from rice-wheat fields in Nepal and maintained on rice cv. BR 11. The isolates were characterized using morphology, host range and DNA sequence analyses in order to ascertain their identity. Results indicated phenotypic similarity (juvenile measurements, perennial pattern, host range and gall shape) of the Nepalese isolates with Meloidogyne graminicola, with minor variations. The rice varieties LA 110 and Labelle were susceptible to all of the Nepalese isolates, but differences in the aggressiveness of the isolates were observed. Phylogenetic analyses based on the sequences of partial internal transcribed spacer (ITS) of the rRNA genes indicated that all Nepalese isolates formed a distinct clade with known isolates of M. graminicola with high bootstrap support. Furthermore, two groups were identified within the M. graminicola clade. No correlation between ITS haplotype and aggressiveness or host range was found among the tested isolates.

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

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Marina Capparelli Cadioli

2009-06-01

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

Impact of salicylic acid- and jasmonic acid-regulated defences on root colonization by Trichoderma harzianum T-78.

Science.gov (United States)

Martínez-Medina, Ainhoa; Appels, Freek V W; van Wees, Saskia C M

2017-08-03

We recently found that the beneficial fungus Trichoderma harzianum T-78 primes tomato plants for salicylic acid (SA)- and jasmonic acid (JA)-regulated defenses, resulting in enhanced resistance against the root knot nematode Meloidogyne incognita. By using SA- and JA-impaired mutant lines and exogenous hormonal application, here we investigated whether the SA- and JA-pathways also have a role in T-78 root colonization of Arabidopsis thaliana. Endophytic colonization by T-78 was faster in the SA-impaired mutant sid2 than in the wild type. Moreover, elicitation of SA-dependent defenses by SA application reduced T-78 colonization, indicating that the SA-pathway affects T-78 endophytism. In contrast, elicitation of the JA-pathway, which antagonized SA-dependent defenses, resulted in enhanced endophytic colonization by T-78. These findings are in line with our previous observation that SA-dependent defenses are repressed by T-78, which likely aids colonization by the endophytic fungus.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Induction of mutations for nematode resistance in tomato

International Nuclear Information System (INIS)

Alameddine, A.

1976-01-01

The objective of this work is to develop resistance to root-knot nematodes in tomato by induction, selection and utilization of the newly created resistant strains. Seeds of two varieties of tomato Lycopersicon esculentum L., namely Amcopack and Supermarmande, were subjected to various doses of gamma rays ranging from 10 Krads to 40 Krads in an effort to gain resistance to Meloidogyne incognita Chitwood, the prevalent species of nematodes in Lebanon. The variety Supermarmande seemed not to be affected by irradiation while Amcopack gained some resistance with a corresponding increase in the dose of radiation. The data suggest that in a variety like Amcopack, irradiation may stimulate resistance while in others like Supermarmande, susceptibility is not reduced with a corresponding increase of dosage. Those alterations in reaction within varieties may be due to genetic differences which allow some varieties to acquire resistance to nematodes when exposed to certain dosages, while others to suffer seriously due to sensitivity. (author)

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

DEFF Research Database (Denmark)

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

2016-01-01

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

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

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Juliana Nogueira Westerich

2012-09-01

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

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

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Tayyaba Zia

2013-12-01

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

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

OpenAIRE

Jada, M. Y.; Gungula, D. T.; Jacob, I.

2011-01-01

Bambara groundnut (Vigna subterrenea L. Verdc.) is an important crop produced in Adamawa State of Nigeria. However, the production of the crop is seriously threatened by root-knot nematodes (RKNs; Meloidogyne spp.). Since cultural methods have not been very effective in controlling RKN, carbofuran was evaluated to determine its efficacy in controlling M. javanica in Yola during 2002 and 2003. Three bambara groundnut cultivars (Kwachanjiwa, Kwaheuma, and Kwatolotolo) were evaluated using three...

Expression of a cystatin transgene in eggplant provides resistance to root-knot nematode, Meloidogyne incognita

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Pradeep Kumar Papolu

2016-07-01

Full Text Available Root-knot nematodes (RKN cause substantial yield decline in eggplant and sustainable management options to minimize crop damage due to nematodes are still limited. A number of genetic engineering strategies have been developed to disrupt the successful plant-nematode interactions. Among them, delivery of proteinase inhibitors from the plant to perturb nematode development and reproduction is arguably the most effective strategy. In the present study, transgenic eggplant expressing a modified rice cystatin (OC-IΔD86 gene under the control of the root-specific promoter, TUB-1, was generated to evaluate the genetically modified nematode resistance. Five putative transformants were selected through PCR and genomic Southern blot analysis. Expression of the cystatin transgene was confirmed in all the events using western blotting, ELISA and qPCR assay. Upon challenge inoculation, all the transgenic events exhibited a detrimental effect on RKN development and reproduction. The best transgenic line (a single copy event showed 78.3% inhibition in reproductive success of RKN. Our results suggest that cystatins can play an important role for improving nematode resistance in eggplant and their deployment in gene pyramiding strategies with other proteinase inhibitors could ultimately enhance crop yield.

Biological Control of Meloidogyne hapla Using an Antagonistic Bacterium

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Jiyeong Park

2014-09-01

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

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

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Vanessa dos Santos Paes-Takahashi

2015-05-01

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

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

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Aura I. Urrea

2012-07-01

Full Text Available Título en ingles: In vitro culture response on Zamia incognita,  an alternative for preservation Resumen: Las Zamiaceas son plantas relictuales consideradas fósiles vivientes. En Colombia, el 65% de esta familia se encuentra en alguna categoría de amenaza, por la destrucción del hábitat e intensa recolección. Teniendo en cuenta que entre las ventajas de la propagación in vitro está la conservación ex situ de germoplasma, el presente trabajo tuvo como objetivo evaluar el potencial de regeneración de plantas de Z. incognita a partir de explantes foliares y embriones cigoticos. Se evaluó el efecto de diferentes combinaciones de Auxinas (2,4-D y ANA y citoquininas (KIN, BAP y TDZ sobre la formación de callo  y la regeneración de brotes (directa o indirecta, utilizando como medio basal MS (MB1 y medio basal B5 modificado (MB2. La formación de callo se presentó sobre un amplio rango de concentraciones de 2,4-D con KIN y 2,4-D con BAP, independientemente del medio basal, pero no en los explantes tratados con ANA más KIN o TDZ.  Para los explantes foliares no hubo respuesta  a la formación de embriones somáticos y/o brotes con las combinaciones y concentraciones hormonales evaluadas, no obstante los callos inducidos en MB2 con 2,4-D (0,22 mg/l y BAP (0, 1, 2, 3 mg/l fueron diferentes, su aspecto nodular, color crema y  apariencia proembriogénica coincidió con una gran cantidad de células meristemáticas potenciales para el proceso de regeneración. A partir de embriones cigoticos inmaduros se logró la formación de embriones somáticos en el medio MB2 exento de reguladores o conteniendo 2,4-D solo (0,22 mg/l y en combinación con BAP (1 mg/l, sin lograr el proceso de conversión a plántulas. Palabras clave: micropropagación; hojas jóvenes; reguladores de crecimiento; embriones cigóticos; medio basal. Abstract: Zamiaceas are relict plants considered living fossils. In Colombia, 65% of this family is under some threat

Nematicides control rice root-knot, caused by Meloidogyne graminicola

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Mujeebur Rahman KHAN

2012-09-01

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

Root-Knot and Cyst Nematodes Activate Procambium-Associated Genes in Arabidopsis Roots

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Yasuka L. Yamaguchi

2017-07-01

Full Text Available Developmental plasticity is one of the most striking features of plant morphogenesis, as plants are able to vary their shapes in response to environmental cues. Biotic or abiotic stimuli often promote organogenesis events in plants not observed under normal growth conditions. Root-knot nematodes (RKNs are known to parasitize multiple species of rooting plants and to induce characteristic tissue expansion called galls or root-knots on the roots of their hosts by perturbing the plant cellular machinery. Galls contain giant cells (GCs and neighboring cells, and the GCs are a source of nutrients for the parasitizing nematode. Highly active cell proliferation was observed in galls. However, the underlying mechanisms that regulate the symptoms triggered by the plant-nematode interaction have not yet been elucidated. In this study, we deciphered the molecular mechanism of gall formation with an in vitro infection assay system using RKN Meloidogyne incognita, and the model plant Arabidopsis thaliana. By taking advantages of this system, we performed next-generation sequencing-based transcriptome profiling, and found that the expression of procambium identity-associated genes were enriched during gall formation. Clustering analyses with artificial xylogenic systems, together with the results of expression analyses of the candidate genes, showed a significant correlation between the induction of gall cells and procambium-associated cells. Furthermore, the promoters of several procambial marker genes such as ATHB8, TDR and WOX4 were activated not only in M. incognita-induced galls, but similarly in M. javanica induced-galls and Heterodera schachtii-induced syncytia. Our findings suggest that phytoparasitic nematodes modulate the host’s developmental regulation of the vascular stem cells during gall formation.

Root-Knot and Cyst Nematodes Activate Procambium-Associated Genes in Arabidopsis Roots.

Science.gov (United States)

Yamaguchi, Yasuka L; Suzuki, Reira; Cabrera, Javier; Nakagami, Satoru; Sagara, Tomomi; Ejima, Chika; Sano, Ryosuke; Aoki, Yuichi; Olmo, Rocio; Kurata, Tetsuya; Obayashi, Takeshi; Demura, Taku; Ishida, Takashi; Escobar, Carolina; Sawa, Shinichiro

2017-01-01

Developmental plasticity is one of the most striking features of plant morphogenesis, as plants are able to vary their shapes in response to environmental cues. Biotic or abiotic stimuli often promote organogenesis events in plants not observed under normal growth conditions. Root-knot nematodes (RKNs) are known to parasitize multiple species of rooting plants and to induce characteristic tissue expansion called galls or root-knots on the roots of their hosts by perturbing the plant cellular machinery. Galls contain giant cells (GCs) and neighboring cells, and the GCs are a source of nutrients for the parasitizing nematode. Highly active cell proliferation was observed in galls. However, the underlying mechanisms that regulate the symptoms triggered by the plant-nematode interaction have not yet been elucidated. In this study, we deciphered the molecular mechanism of gall formation with an in vitro infection assay system using RKN Meloidogyne incognita , and the model plant Arabidopsis thaliana. By taking advantages of this system, we performed next-generation sequencing-based transcriptome profiling, and found that the expression of procambium identity-associated genes were enriched during gall formation. Clustering analyses with artificial xylogenic systems, together with the results of expression analyses of the candidate genes, showed a significant correlation between the induction of gall cells and procambium-associated cells. Furthermore, the promoters of several procambial marker genes such as ATHB8 , TDR and WOX4 were activated not only in M. incognita -induced galls, but similarly in M. javanica induced-galls and Heterodera schachtii -induced syncytia. Our findings suggest that phytoparasitic nematodes modulate the host's developmental regulation of the vascular stem cells during gall formation.

Effects of Tropical Rotation Crops on Meloidogyne arenaria Population Densities and Vegetable Yields in Microplots.

Science.gov (United States)

McSorley, R; Dickson, D W; de Brito, J A; Hewlett, T E; Frederick, J J

1994-06-01

The effects of 12 summer crop rotation treatments on population densities of Meloidogyne arenaria race 1 and on yields of subsequent spring vegetable crops were determined in microplots. The crop sequence was: (i) rotation crops during summer 1991 ; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) eggplant (Solanum melongena) during spring 1993. The 12 rotation treatments were castor (Ricinus communis), cotton (Gossypium hirsutum), velvetbean (Mucuna deeringiana), crotalaria (Crotalaria spectabilis), fallow, hairy indigo (Indigofera hirsuta), American jointvetch (Aeschynomene americana), sorghum-sudangrass (Sorghum bicolor x S. sudanense), soybean (Glycine max), horsebean (Canavalia ensiformis), sesame (Sesamum indicum), and peanut (Arachis hypogaea). Compared to peanut, the first eight rotation treatments resulted in lower (P crops may provide a means for depressing M. arenaria population densities on a short-term basis to enhance yields in a subsequent susceptible vegetable crop.

Phenotypic and molecular analysis of a pasteuria strain parasitic to the sting nematode.

Science.gov (United States)

Bekal, S; Borneman, J; Springer, M S; Giblin-Davis, R M; Becker, J O

2001-06-01

Pasteuria strain S-1 was found to parasitize the sting nematode Belonolaimus longicaudatus. S-1 spores attached to several strains of B. longicaudatus from different geographical locations within the United States. However, they did not adhere to any of the following species: Heterodera schachtii, Longidorus africanus, Meloidogyne hapla, M. incognita, M. javanica, Pratylenchus brachyurus, P. scribneri, P. neglectus, P. penetrans, P. thornei, P. vulnus, and Xiphinema spp. The 16S rRNA genes from Pasteuria strain S-1 and P. penetrans strain Pp from Senegal were obtained by PCR amplification. A DNA sequence analysis showed that the S-1 16S rRNA had 96% or less similarity to the 16S rRNA genes from all previously reported Pasteuria species. Diverse phylogenetic methods all provided robust support for an association of Pasteuria strain S-1, Pasteuria strain NA parasitic to H. glycines, and P. penetrans strain Pp, to the exclusion of P. ramosa. In addition, our study showed intraspecific variation within P. penetrans as inferred by its 98% similarity to P. penetrans strain Pp.

Ectopic expression of AtPAD4 broadens resistance of soybean to soybean cyst and root-knot nematodes.

Science.gov (United States)

Youssef, Reham M; MacDonald, Margaret H; Brewer, Eric P; Bauchan, Gary R; Kim, Kyung-Hwan; Matthews, Benjamin F

2013-04-25

The gene encoding PAD4 (PHYTOALEXIN-DEFICIENT4) is required in Arabidopsis for expression of several genes involved in the defense response to Pseudomonas syringae pv. maculicola. AtPAD4 (Arabidopsis thaliana PAD4) encodes a lipase-like protein that plays a regulatory role mediating salicylic acid signaling. We expressed the gene encoding AtPAD4 in soybean roots of composite plants to test the ability of AtPAD4 to deter plant parasitic nematode development. The transformed roots were challenged with two different plant parasitic nematode genera represented by soybean cyst nematode (SCN; Heterodera glycines) and root-knot nematode (RKN; Meloidogyne incognita). Expression of AtPAD4 in soybean roots decreased the number of mature SCN females 35 days after inoculation by 68 percent. Similarly, soybean roots expressing AtPAD4 exhibited 77 percent fewer galls when challenged with RKN. Our experiments show that AtPAD4 can be used in an economically important crop, soybean, to provide a measure of resistance to two different genera of nematodes.

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

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Gubin A.I.

2014-07-01

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

Rhizosphere Microbiomes Modulated by Pre-crops Assisted Plants in Defense Against Plant-Parasitic Nematodes

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Ahmed Elhady

2018-06-01

Full Text Available Plant-parasitic nematodes cause considerable damage to crop plants. The rhizosphere microbiome can affect invasion and reproductive success of plant-parasitic nematodes, thus affecting plant damage. In this study, we investigated how the transplanted rhizosphere microbiome from different crops affect plant-parasitic nematodes on soybean or tomato, and whether the plant’s own microbiome from the rhizosphere protects it better than the microbiome from fallow soil. Soybean plants growing in sterilized substrate were inoculated with the microbiome extracted from the rhizosphere of soybean, maize, or tomato. Controls were inoculated with extracts from bulk soil, or not inoculated. After the microbiome was established, the root lesion nematode Pratylenchus penetrans was added. Root invasion of P. penetrans was significantly reduced on soybean plants inoculated with the microbiome from maize or soybean compared to tomato or bulk soil, or the uninoculated control. In the analogous experiment with tomato plants inoculated with either P. penetrans or the root knot nematode Meloidogyne incognita, the rhizosphere microbiomes of maize and tomato reduced root invasion by P. penetrans and M. incognita compared to microbiomes from soybean or bulk soil. Reproduction of M. incognita on tomato followed the same trend, and it was best suppressed by the tomato rhizosphere microbiome. In split-root experiments with soybean and tomato plants, a systemic effect of the inoculated rhizosphere microbiomes on root invasion of P. penetrans was shown. Furthermore, some transplanted microbiomes slightly enhanced plant growth compared to uninoculated plants. The microbiomes from maize rhizosphere and bulk soil increased the fresh weights of roots and shoots of soybean plants, and microbiomes from soybean rhizosphere and bulk soil increased the fresh weights of roots and shoots of tomato plants. Nematode invasion did not affect plant growth in these short-term experiments. In

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

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Beom Ryong Kang

2018-02-01

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

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

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

2011-01-01

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

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

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Yu Yu Min

2011-01-01

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

Genetic diversity, virulence, and Meloidogyne incognita interactions of Fusarium oxysporum isolates causing cotton wilt in Georgia

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Locally severe outbreaks of Fusarium wilt of cotton (Gossypium spp.) in South Georgia raised concerns about the genotypes of the causal pathogen, Fusarium oxysporum f. sp. vasinfectum. Vegetative complementation tests and DNA sequence analysis were used to determine genetic diversity among 492 F. ox...

Assessment of DAPG-producing Pseudomonas fluorescens for management of Meloidogyne incognita and Fusarium oxysporum on watermelon

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Pseudomonas fluorescens isolates Clinto 1R, Wayne 1R and Wood 1R, which produce the antibiotic 2,4-diacetylphloroglucinol (DAPG), can suppress soilborne diseases and promote plant growth. Consequently, these beneficial bacterial isolates were tested on watermelon plants for suppression of Meloidogy...

Effectiveness of the native strain of Bacillus subtilis as a suppressant agent of the nematode Meloidogyne spp knot in cultures of Capsicum annuum “piquillo pepper chili”

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Nancy Mercedes Soto Deza

2012-05-01

Full Text Available In croping fields infested with nematodes, the RCBD complete blocks design was applied. 85% pure chicken manure was also incorporated, 15 t / ha and 30 t /. Spores of B. subtilis, 1 X106 eng / mL and 2 x 106 sperm / mL Capsicum annuum seeds in direct seeding were inoculated (experiment I and transplantation (experiment II. At 45 and 90 days analysis of nematode populations were determined, nodulation index, plant height and fruit number. The data was subjected to analysis of variance using the Statgraphics Plus 5.0 software. To estimate the significant differences between treatments, the Tukey test was applied. Initially, the study showed highly infested knot nematode Meloidogyne spp., 275 to 27720 soil nematodes/100 cm3, and in Trial II it was between 9 and 1 nematodes/100 cm3 of soil, with significant difference (P & 0.05. The final population recorded after the application of Bacillus subtilis, was 13 and 0 nematodes/100 cm3 of soil, the nematode  population levels, decreased significantly, showing significant difference (P & 0.05. Efficacy of B. subtilis on Meloidogyne spp., it was clear, reduced initial populations of the nematode, reaching a reproduction rate less than 1, non-galling index reached grade 3. The interaction of B. subtilis with poultry manure amendment favored the production achieved in the cultivation of Capsicum annuum.

Ação nematicida de extratos de alho, mostarda, pimenta malagueta, de óleo de mostarda e de dois produtos à base de capsainóides e alil isotiocianato sobre juvenis de Meloidogyne javanica, (treub Chitwood, 1949, em casa de vegetação

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Wânia dos Santos Neves

2009-12-01

Full Text Available Neves, W.S; Freitas, L.G.; Coutinho, M.M.; Giaretta-Dallemole, R.; Fabry, C.F.S.; Dhingra, O.D. & Ferraz, S. Atividade nematicida de extratos botânicos de pimenta malagueta (Capsicum frutescens, mostarda (Brassica campestris e alho (Allium sativum sobre o nematóide das galhas, Meloidogyne javanica, em casa de vegetação. Summa Phytopathologica, v.35, n.4, p.255-261, 2009 O experimento teve como objetivo avaliar a atividade nematicida de extratos botânicos dos frutos de pimenta malagueta (Capsicum frutescens, plantas de mostarda (Brassica campestris, de bulbos de alho (Allium sativum e óleo de mostarda sobre o nematóide das galhas, Meloidogyne javanica, em tomateiro em casa de vegetação e posteriormente comparar os extratos que apresentassem maior redução de número de galhas e de ovos com dois produtos à base de capsaicina, capsainóides e alil isotiocianato. Uma mistura peneirada de solo e areia na proporção 1:1 (v:v foi colocada em vasos de plástico e infestada com 4000 ovos de M. javanica. Quatro dias após 20 mL de cada extrato, na concentração de 1000 ppm, foram espalhados sobre o solo. Apenas água foi derramada sobre o solo infestado no tratamento testemunha. Mudas de tomate com 20 dias de idade foram transplantadas quatro dias após a colocação dos extratos ao solo. Após quarenta e cinco dias avaliou-se o número de ovos e o número de galhas do sistema radicular de cada planta. Os extratos clorofórmico e cetônico de pimenta malagueta e o óleo de mostarda apresentaram melhor controle do nematóide, diferindo estatisticamente da testemunha quanto ao número de galhas. Porém, somente o óleo de mostarda reduziu significativamente o número de ovos quando comparado com a testemunha. Os extratos cetônico e clorofórmico de pimenta e o óleo de mostarda reduziram em 34,5%, 40,4% e 99,9% o número de galhas, respectivamente e o óleo de mostarda reduziu em 99,9% o número de ovos. No experimento seguinte foram avaliados

Interaction of Vesicular-Arbuscular Mycorrhizae and Cultivars of Alfalfa Susceptible and Resistant to Meloidogyne hapla.

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Grandison, G S; Cooper, K M

1986-04-01

The interaction between vesicular-arbuscular mycorrhizal (VAM) fungi and the root-knot nematode (Meloidogyne hapla) was investigated using both nematode-susceptible (Grasslands Wairau) and nematode-resistant (Nevada Synthetic XX) cultivars of alfalfa (Medicago sativa) at four levels of applied phosphate. Mycorrhizal inoculation improved plant growth and reduced nematode numbers and adult development in roots in dually infected cultures of the susceptible cultivar. The tolerance of plants to nematode infection and development when preinfected with mycorrhizal fungi was no greater than when they were inoculated with nematodes and mycorrhizal fungi simultaneously. Growth of plants of the resistant cultivar was unaffected by nematode inoculation but was improved by mycorrhizal inoculation. Numbers of nematode juveniles were lower in the roots of the resistant than of the susceptible cultivar and were further reduced by mycorrhizal inoculation, although no adult nematodes developed in any resistant cultivar treatment. Inoculation of alfalfa with VAM fungi increased the tolerance and resistance of a cultivar susceptible to M. hapla and improved the resistance of a resistant cultivar.

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

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Xiujuan Yang

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

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

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Etienne G J Danchin

2013-10-01

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

Meloidogyne javanica control by Pochonia chlamydosporia, Gracilibacillus dipsosauri and soil conditioner in tomato

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Guilherme Silva de Podestá

2013-06-01

Full Text Available Organic matter plays a fundamental role in the antagonistic activity of microorganisms against phytonematode populations on the soil. In this study, the compatibility between the fungus Pochonia chlamydosporia (Pc-12 and the rhizobacterium Gracilibacillus dipsosauri (MIC 14 was evaluated in vitro, as well as the effect of the fungus at the concentration of 5,000 chlamydospores per gram of soil, rhizobacterium at 4.65 x 10(9 cells/g of soil, and the soil conditioner Ribumin® at 10 g/pot, either alone or in combination, against Meloidogyne javanica population in tomato plants (3,000 eggs/pot. A suspension of water or Ribumin® alone was applied on the soil as negative control, while a suspension of nematode eggs was applied as positive control. The reduction in the number of galls in roots per plant was 48 and 41% for the treatments Ribumin + MIC 14 + Pc-12 and MIC 14 + Pc-12, respectively. Regarding to the number of eggs per plant, MIC 14 and Pc-12 + Ribumin led to a reduction by 26 and 21%, respectively, compared to the control treatment. Interaction between the nematophagous fungus and the rhizobacterium was positive for the nematode control, even though G. dipsosauri inhibited P. chlamydosporia growth by up to 30% in in vitro tests.

Population dynamics of Meloidogyne arenaria and Pasteuria penetrans in a long-term crop rotation study.

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Timper, Patricia

2009-12-01

The endospore-forming bacterium Pasteuria penetrans is an obligate parasite of root-knot nematodes (Meloidogyne spp.). The primary objective of this study was to determine the effect of crop sequence on abundance of P. penetrans. The experiment was conducted from 2000 to 2008 at a field site naturally infested with both the bacterium and its host Meloidogyne arenaria and included the following crop sequences: continuous peanut (Arachis hypogaea) (P-P-P) and peanut rotated with either 2 years of corn (Zea mays) (C-C-P), 1 year each of cotton (Gossypium hirsutum) and corn (Ct-C-P), or 1 year each of corn and a vegetable (V-C-P). The vegetable was a double crop of sweet corn and eggplant (Solanum melongena). A bioassay with second-stage juveniles (J2) of M. arenaria from a greenhouse (GH) population was used to estimate endospore abundance under the different crop sequences. A greater numerical increase in endospore densities was expected in the P-P-P and V-C-P sequences than in the other sequences because both peanut and eggplant are good hosts for M. arenaria. However, endospore densities, as determined by bioassay, did not substantially increase in any of the sequences during the 9-year experiment. To determine whether the nematode population had developed resistance to the resident P. penetrans, five single egg-mass (SEM) lines from the field population of M. arenaria were tested alongside the GH population for acquisition of endospores from the field soil. Four of the five SEM lines acquired 9 to 14 spores/J2 whereas the GH population and one of the SEM lines acquired 3.5 and 1.8 spores/J2, respectively. Endospore densities estimated with the four receptive SEM lines were highest in the P-P-P plots (14-20 spores/J2), intermediate in the V-C-P plots (6-7 spores/J2), and lowest in the Ct-C-P plots (< 1 spore/J2). These results indicate that the field population of M. arenaria is heterogeneous for attachment of P. penetrans endospores. Moreover, spore densities

Population Dynamics of Meloidogyne arenaria and Pasteuria penetrans in a Long-Term Crop Rotation Study

Science.gov (United States)

2009-01-01

The endospore-forming bacterium Pasteuria penetrans is an obligate parasite of root-knot nematodes (Meloidogyne spp.). The primary objective of this study was to determine the effect of crop sequence on abundance of P. penetrans. The experiment was conducted from 2000 to 2008 at a field site naturally infested with both the bacterium and its host Meloidogyne arenaria and included the following crop sequences: continuous peanut (Arachis hypogaea) (P-P-P) and peanut rotated with either 2 years of corn (Zea mays) (C-C-P), 1 year each of cotton (Gossypium hirsutum) and corn (Ct-C-P), or 1 year each of corn and a vegetable (V-C-P). The vegetable was a double crop of sweet corn and eggplant (Solanum melongena). A bioassay with second-stage juveniles (J2) of M. arenaria from a greenhouse (GH) population was used to estimate endospore abundance under the different crop sequences. A greater numerical increase in endospore densities was expected in the P-P-P and V-C-P sequences than in the other sequences because both peanut and eggplant are good hosts for M. arenaria. However, endospore densities, as determined by bioassay, did not substantially increase in any of the sequences during the 9-year experiment. To determine whether the nematode population had developed resistance to the resident P. penetrans, five single egg-mass (SEM) lines from the field population of M. arenaria were tested alongside the GH population for acquisition of endospores from the field soil. Four of the five SEM lines acquired 9 to 14 spores/J2 whereas the GH population and one of the SEM lines acquired 3.5 and 1.8 spores/J2, respectively. Endospore densities estimated with the four receptive SEM lines were highest in the P-P-P plots (14-20 spores/J2), intermediate in the V-C-P plots (6-7 spores/J2), and lowest in the Ct-C-P plots (< 1 spore/J2). These results indicate that the field population of M. arenaria is heterogeneous for attachment of P. penetrans endospores. Moreover, spore densities

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

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Sônia Maria de Lima Salgado

2007-08-01

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

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

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Marina Capparelli Cadioli

2007-04-01

Full Text Available Paecilomyces lilacinus é um fungo de solo, parasita facultativo de ovos de nematóides, que pode crescer rapidamente "in vitro". Este trabalho teve como objetivo avaliar o crescimento micelial de P. lilacinus em diferentes temperaturas e selecionar os melhores isolados quanto à capacidade de parasitar ovos de Meloidogyne paranaensis. Foram avaliados isolados de P. lilacinus, obtidos de solos coletados na região de Londrina, PR. Para o isolamento empregou-se a técnica de diluição seriada dos solos e plaqueamento em meio de cultura semi-seletivo. A determinação do crescimento micelial e do parasitismo "in vitro" dos isolados sobre M. paranaensis foi realizada em placas de Petri contendo meio BDA. Os isolados foram incubados em B.O.D. a temperaturas de 20ºC, 22,5ºC, 25ºC, 27,5ºC e 30ºC. A avaliação do crescimento foi interrompida quando em um dos tratamentos a colônia do fungo atingiu a borda da placa de Petri e a determinação do parasitismo foi realizada depois de oito dias de incubação, calculando-se a porcentagem de ovos parasitados. O crescimento micelial dos isolados de P. lilacinus teve grande dependência da temperatura de incubação a que foram submetidos, sendo mais rápido à temperatura de 22,5ºC. Os isolados de P. lilacinus revelaram habilidade para infectar os ovos de M. paranaensis em meio BDA, principalmente na temperatura de 25ºC.Paecilomyces lilacinus is a soil fungus, facultative parasite of nematode eggs, which develops quickly "in vitro". The mycelial growth of P. lilacinus isolates was evaluated at different temperatures and the best isolates, regarding the capacity to parasite Meloidogyne paranaensis eggs, were chosen. P. lilacinus soil isolates from Londrina, Parana state, were evaluated. Isolation was done using serial dilution of the soils and plating it in semi-selective agar medium. The determination of mycelial growth and "in vitro" parasitism of these isolates was done using Petri plates

RNAi effector diversity in nematodes.

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Johnathan J Dalzell

2011-06-01

Full Text Available While RNA interference (RNAi has been deployed to facilitate gene function studies in diverse helminths, parasitic nematodes appear variably susceptible. To test if this is due to inter-species differences in RNAi effector complements, we performed a primary sequence similarity survey for orthologs of 77 Caenorhabditis elegans RNAi pathway proteins in 13 nematode species for which genomic or transcriptomic datasets were available, with all outputs subjected to domain-structure verification. Our dataset spanned transcriptomes of Ancylostoma caninum and Oesophagostomum dentatum, and genomes of Trichinella spiralis, Ascaris suum, Brugia malayi, Haemonchus contortus, Meloidogyne hapla, Meloidogyne incognita and Pristionchus pacificus, as well as the Caenorhabditis species C. brenneri, C. briggsae, C. japonica and C. remanei, and revealed that: (i Most of the C. elegans proteins responsible for uptake and spread of exogenously applied double stranded (dsRNA are absent from parasitic species, including RNAi-competent plant-nematodes; (ii The Argonautes (AGOs responsible for gene expression regulation in C. elegans are broadly conserved, unlike those recruited during the induction of RNAi by exogenous dsRNA; (iii Secondary Argonautes (SAGOs are poorly conserved, and the nuclear AGO NRDE-3 was not identified in any parasite; (iv All five Caenorhabditis spp. possess an expanded RNAi effector repertoire relative to the parasitic nematodes, consistent with the propensity for gene loss in nematode parasites; (v In spite of the quantitative differences in RNAi effector complements across nematode species, all displayed qualitatively similar coverage of functional protein groups. In summary, we could not identify RNAi effector deficiencies that associate with reduced susceptibility in parasitic nematodes. Indeed, similarities in the RNAi effector complements of RNAi refractory and competent nematode parasites support the broad applicability of this research

Effects of catechins and low temperature on embryonic development and hatching in Heterodera glycines and Meloidogyne incognita

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Mimics of two natural influences, a chemical similar to one present in cyst nematodes and low temperature exposure of nematode eggs, were evaluated for their effects on quantitative and qualitative features of embryonic development and hatching. The polyphenol epigallocatechin gallate (EGCG), an ana...

Ação de extratos de plantas medicinais sobre juvenis de Meloidogyne incognita raça 2

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Maria da Conceição Beserra Martins

Full Text Available RESUMO Os fitonematoides são parasitas que afetam seriamente as culturas em todo o mundo comprometendo a produção agrícola e, por vezes, inviabilizando a utilização de numerosas áreas de cultivo. A busca por medidas alternativas de controle em substituição aos nematicidas convencionais é uma preocupação mundial, justificando pesquisas com substâncias naturais por serem eficientes e ecologicamente corretos. Objetivou-se neste trabalho avaliar o efeito de extratos vegetais de agrião-do-brejo (Eclipta alba L., alfavaca (Ocimum basilicum, artemísia (Artemísia vulgaris, capim citronela (Cymbopogon winteranus, chambá (Justicia pectoralis, confrei (Symphytum officinalle, hortelã (Mentha x vilosa, lombrigueira (Spigelia anthelmia, mastruz (Chenopodium ambrosioides e menta (Mentha arvensis na motilidade e mortalidade de juvenis de Meloidogyneincognita raça 2. Os extratos, obtidos a partir de folhas secas sob infusão ou sob maceração em água, foram diluídos e distribuídos em placas de Petri às quais foram adicionados 50 juvenis de segundo estádio (J2. Após permanecerem por 48 horas nos extratos, todos os J2 móveis ou imóveis foram contados e, em seguida, transferidos para água determinando-se, após 24 horas, a porcentagem de J2 mortos. Os J2 ainda ativos foram inoculados em mudas de tomateiro ‘Santa Clara’ em casa de vegetação para avaliar a sua infectividade. Os extratos macerados das plantas medicinais, excetuando-se capim citronela, hortelã e menta, apresentaram alta atividade nematicida com mais de 70% de J2 mortos. Mortalidade total ocorreu em extratos de lombrigueira, agrião-do-brejo e mastruz. A ausência de galhas nas raízes de tomateiros inoculados confirmou o efeito tóxico desses extratos.

Chemical constituents of Cordia latifolia and their nematicidal activity.

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Begum, Sabira; Perwaiz, Sobiya; Siddiqui, Bina S; Khan, Shazia; Fayyaz, Shahina; Ramzan, Musarrat

2011-05-01

Following nematicidal activity-guided isolation studies on the fruits, bark, and leaves of Cordia latifolia, two new constituents, cordinoic acid (=11-oxours-12-ene-23,28-dioic acid; 1) and cordicilin (=2-{[(E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}-3-[4-hydroxy-3-(stearoyloxy)phenyl]propanoic acid; 2) were isolated from the stem and leaves, respectively, together with nine known compounds, namely cordioic and cordifolic acid from the stem bark, latifolicin A-D and rosmarinic acid from the fruits, and cordinol and cordicinol from the leaves. Their structures were determined by means of spectroscopic analyses including 1D- and 2D-NMR techniques. The nematicidal activities of these constituents were determined against the root-knot nematode Meloidogyne incognita. Hundred percent mortality was caused by all of these after 72 h at a 0.125% concentration. Compound 1 and cordioic acid were most active and caused 100% mortality after 24 h at a 0.50% concentration. Furthermore, compound 2, the ester of rosemarinic acid, was found to be more active than the free acid. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

Evaluation of root-knot nematode disease control and plant growth promotion potential of biofertilizer Ning shield on Trichosanthes kirilowii in the field.

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Jiang, Chun-Hao; Xie, Ping; Li, Ke; Xie, Yue-Sheng; Chen, Liu-Jun; Wang, Jin-Suo; Xu, Quan; Guo, Jian-Hua

Biofertilizer Ning shield was composed of different strains of plant growth promotion bacteria. In this study, the plant growth promotion and root-knot nematode disease control potential on Trichosanthes kirilowii in the field were evaluated. The application of Ning shield significantly reduced the diseases severity caused by Meloidogyne incognita, the biocontrol efficacy could reached up to 51.08%. Ning shield could also promote the growth of T. kirilowii in the field by increasing seedling emergence, height and the root weight. The results showed that the Ning shield could enhance the production yield up to 36.26%. Ning shield could also promote the plant growth by increasing the contents of available nitrogen, phosphorus, potassium and organic matter, and increasing the contents of leaf chlorophyll and carotenoid pigment. Moreover, Ning shield could efficiently enhance the medicinal compositions of Trichosanthes, referring to the polysaccharides and trichosanthin. Therefore, Ning shield is a promising biofertilizer, which can offer beneficial effects to T. kirilowii growers, including the plant growth promotion, the biological control of root-knot disease and enhancement of the yield and the medicinal quality. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Incorporation of disease resistance from Lycopersicon peruvianum L. to cultivated tomatoes, 1: Breeding of new varieties ''Ryugyoku'' etc., having resistance to Fusarium root rot and tobacco mosaic virus inherited from L. peruvianum

International Nuclear Information System (INIS)

Yamakawa, K.; Yasui, H.; Mochizuki, T.; Hida, K.; Komochi, S.

1987-01-01

Fusarium crown and root rot (FCR) resistance and Tobacco Mosaic Virus (TMV) resistance (Tm-2) of a wild tomato (Lycopersicon peruvianum) were incorporated into cultivated tomatoes (L. esculentum). With this material, F1 hybrid varieties 'Kagyoku, Ryugyoku' and their parental lines 'Tomato parental lines No. 4, -No. 5' were developed. In addition, 'Kagyoku, Ryugyoku' possess Fusarium wild (J1), Nematode (Meloidogyne incognita) and TMV (Tm-2a) resistance introduced from the other varieties. Among the resistances introduced from L. peruvianum, TMV resistance is simply inherited and stable enough. FCR resistance is basically monogenic, but the strong influence of the genetic background hinders the development of FCR resistant varieties with high quality and yield. Whereas 'Ryugyoku' which is highly resistant to FCR has less attractive fruit characters, 'Kagyoku' yields fruits of high quality with a comparatively low FCR resistance. In this report, the breeding process from interspecific hybridization to the development of F1 varieties and the methods of selection applied were described. Also the difficulties which arose in the process of incorporation of the resistance from the wild species were discussed

Tropical rotation crops influence nematode densities and vegetable yields.

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McSorley, R; Dickson, D W; de Brito, J A; Hochmuth, R C

1994-09-01

The effects of eight summer rotation crops on nematode densities and yields of subsequent spring vegetable crops were determined in field studies conducted in north Florida from 1991 to 1993. The crop sequence was as follows: (i) rotation crops during summer 1991; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) 'Lemondrop L' squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) 'Classic' eggplant (Solanum melongena) during spring 1993. The eight summer crop rotation treatments were as follows: 'Hale' castor (Ricinus communis), velvetbean (Mucuna deeringiana), sesame (Sesamum indicum), American jointvetch (Aeschynomene americana), weed fallow, 'SX- 17' sorghum-sudangrass (Sorghum bicolor x S. sudanense), 'Kirby' soybean (Glycine max), and 'Clemson Spineless' okra (Hibiscus esculentus) as a control. Rotations with castor, velvetbean, American jointvetch, and sorghum-sudangrass were most effective in maintaining the lowest population densities of Meloidogyne spp. (a mixture of M. incognita race 1 and M. arenaria race 1), but Paratrichodorus minor built up in the sorghum-sudangrass rotation. Yield of squash was lower (P crops evaluated here may be useful for managing nematodes in the field and for improving yields of subsequent vegetable crops.

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

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Marcielly F. Turatto

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

Development of Pasteuria penetrans in Meloidogyne javanica females as affected by constantly high vs fluctuating temperature in an in-vivo system.

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Darban, D A; Gowen, S R; Pembroke, B; Mahar, A N

2005-03-01

Growth room and glasshouse experiment was conducted to investigate the effect of constant and fluctuating temperatures on the development of Pasteuria penetrans a hyperparasite of root-knot nematodes. Tomato plants (Lycopersicon esculentum Mill) were inoculated with Meloidogyne javanica second-stage juveniles attached with endospores of P. penetrans and were grown in growth room at 26-29 degrees C and in glasshouse at 20-32 degrees C. The tomato plants were sampled from the growth room after 600 degree-days based on 17 degrees C/d, accumulating each day above a base temperature of 10 degrees C and from the glasshouse after 36 calendar days. Temperature affected the development of P. penetrans directly. The rate of development at constant temperature in growth room was faster than that in the glasshouse at fluctuating temperatures.

Persistence and Suppressiveness of Pasteuria penetrans to Meloidogyne arenaria Race.

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Cetintas, R; Dickson, D W

2004-12-01

The long-term persistence and suppressiveness of Pasteuria penetrans against Meloidogyne arenaria race 1 were investigated in a formerly root-knot nematode suppressive site following 9 years of continuous cultivation of three treatments and 4 years of continuous peanut. The three treatments were two M. arenaria race 1 nonhost crops, bahiagrass (Paspalum notatum cv. Pensacola var. Tifton 9), rhizomal peanut (Arachis glabrata cv. Florigraze), and weed fallow. Two root-knot nematode susceptible weeds commonly observed in weed fallow plots were hairy indigo (Indigofera hirsuta) and alyce clover (Alysicarpus vaginalis). The percentage of J2 with endospores attached reached the highest level of 87% in 2000 in weed fallow, and 63% and 53% in 2002 in bahiagrass and rhizomal peanut, respectively. The percentage of endospore-filled females extracted from peanut roots grown in weed fallow plots increased from nondetectable in 1999 to 56% in 2002, whereas the percentages in bahiagrass and rhizomal peanut plots were 41% and 16%, respectively. Over 4 years, however, there was no strong evidence that endospores densities reached suppressive levels because peanut roots, pods, and pegs were heavily galled, and yields were suppressed. This might be attributed to the discovery of M. javanica infecting peanut in this field in early autumn 2001. A laboratory test confirmed that although the P. penetrans isolate specific to M. arenaria attached to M. javanica J2, no development occurred. In summary, P. penetrans increased on M. arenaria over a 4-year period, but apparently because of infection of M. javanica on peanut at the field site root-knot disease was not suppressed. This was confirmed by a suppressive soil test that showed a higher level of soil suppressiveness than occurred in the field (P

Detection of Pasteuria penetrans infection in Meloidogyne arenaria race 1 in planta by polymerase chain reaction.

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Schmidt, L M; Preston, J F; Nong, G; Dickson, D W; Aldrich, H C

2004-06-01

We report on the development of a PCR-based assay to detect Pasteuria penetrans infection of Meloidogyne arenaria in planta using specific primers for recently sequenced sigE, spoIIAB and atpF genes of P. penetrans biotype P20. Amplification of these genes in crude DNA extracts of ground tomato root galls using real-time kinetic PCR distinguished infected from uninfected M. arenaria race 1 by analysis of consensus thresholds for single copy genes. Fluorescent in situ hybridization (FISH) using the sigE primer sequence as a probe shows hybridization to P. penetrans cells in various stages of vegetative (pre-endospore) development. Ratios of gene copies for sigE and 16S rDNA were obtained for P. penetrans and compared to Bacillus subtilis as a genomic paradigm of endospore-forming bacteria. Phylogenetic analysis of the sigE gene from Gram-positive, endospore-forming bacteria finds P. penetrans most closely related Paenbacillus polymyxa. The sporulation genes (spo genes), particularly sigE, have sequence diversity that recommends them for species and biotype differentiation of the numerous Pasteuria isolates that infect a large number of plant-parasitic nematodes.

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

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

2009-09-01

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

Soil organisms associated to the weed suppressant Crotalaria juncea (fabaceae and its importance as a refuge for natural enemies Organismos de solo associados à supressora de plantas daninhas Crotalaria juncea (fabaceae e sua importância como refúgio para inimigos naturais

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W.S Tavares

2011-09-01

Full Text Available Soil organisms play an important role in organic crops of Crotalaria juncea (Fabaceae and are associated with the natural conservation of the environment. The present study was aimed to investigate the population of soil organisms in the organic culture of C. juncea, as well as its importance as a refuge for natural enemies. Dalbulus maidis (Hemiptera: Cicadellidae, Diabrotica sp. (Coleoptera: Chrysomelidae, Doru luteipes (Dermaptera: Forficulidae, Gryllus assimilis (Orthoptera: Gryllidae, Lagria villosa (Coleoptera: Lagriidae, Melanotus sp. (Coleoptera: Elateridae, Meloidogyne incognita (Tylenchida: Heteroderidae, Nephila clavipes (Araneae: Nephilidae, Orius insidiosus (Hemiptera: Anthocoridae, Pheidole sp. (Hymenoptera: Myrmicidae, Phyllophaga sp. (Coleoptera: Scarabeidae, Procornitermes sp. (Isoptera: Termitidae, Solenopsis sp. (Hymenoptera: Formicidae, and Utetheisa ornatrix (Lepidoptera: Arctiidae were identified in C. juncea. The organisms that were found during a 3-month period in 144 trenches in C. juncea were pest species (84.47% and natural enemies (15.53% as well. Natural enemies had an average of 11.89 individuals per 1.08 m³ of soil cultivated with C. juncea. The abundance of organisms in the pod stage (5.49% of C. juncea was lower than that in the vegetative (83.50% and flowering (11.01% stages. Crotalaria juncea plants can be used as part of a crop system for Integrated Pest Management.Organismos de solo desempenham um importante papel em cultivos orgânicos de Crotalaria juncea (Fabaceae e estão associados com a conservação natural do ambiente. O presente estudo teve como objetivo investigar a população de organismos de solo no cultivo orgânico de C. juncea, bem como sua importância como um refúgio para inimigos naturais. Dalbulus maidis (Hemiptera: Cicadellidae, Diabrotica sp. (Coleoptera: Chrysomelidae, Doru luteipes (Dermaptera: Forficulidae, Gryllus assimilis (Orthoptera: Gryllidae, Lagria villosa (Coleoptera

Influência da adubação e da fumigação do solo, na incidência de nematôides em tubérculos de batatinha Influence of fertilizers and soil fumigation on the nematode incidence of potato tubers

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O. J. Boock

1959-01-01

Full Text Available Dentre as causas que podem levar ao fracasso a cultura da batatinha (Solanum tuberosum L. no Brasil, sobressaem as devidas aos nematóides causadores de galhas ou pipoca Meloidogyne incognita (Kofoide & White, 1919 Chitwood, 1949. Os tubérculos, quando atacados, tornam-se impróprios ao plantio e ao consumo apodrecendo rapidamente. Em vista dêsse fato vêm sendo realizadas, no Instituto Agronômico de Campinas, experiências visando ao combate àquela praga. Os resultados obtidos ultimamente, quando se procurou constatar a influência sôbre a redução da infestação exercida pelas adubações e pelas fumigações do solo com dibrometo de etileno, forneceram os seguintes esclarecimentos: a adubação não exerceu nenhuma influência sôbre o aumento ou diminuição das infestações dos tubérculos pelos nematóides; o dibrometo de etileno mostrou-se eficiente na redução da infestação, na dose de 276 litros por hectare, não devendo, todavia, ser aplicado no terreno no ato do plantio da batatinha mas sim com antecedência de oito ou mais dias; o melhor espaçamento entre aplicações foi o de 20x20 cm; a produção de tubérculos aumentou satisfatoriamente com a fumigação, principalmente quando o nematocida foi aplicado duas vezes no mesmo terreno, isto é, antes de cada uma das culturas ("da sêca" e "das águas".The most important losses caused by root nematodes to the potato crop in the State of Silo Paulo and other parts of Brazil are due to the species Meloidogyne incognita (Kofoide & White, 1919 Chitwood, 1949 and Pralylenchus steineri Lordello, Zamith & Boock, 1954. The former is quite widespread and measures aiming at its control were studied under field conditions. The present paper reports the results on the influence of fertilizer and soil fumigation with ethilene dibromide at 10%, cither separately or combined, on the nematode infestation of the potato yield. The results of the tests showed that the fertilizer application

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

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Rodrigo Vieira Silva

2015-06-01

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

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

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Tina Kyndt

2017-06-01

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

EFECTO DE POBLACIONES DE Meloidogyne sp. EN EL DESARROLLO Y RENDIMIENTO DEL TOMATE

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Wilber Salazar-Ant\\u00F3n

2013-01-01

Full Text Available El objetivo de este trabajo fue determinar el efecto de la población inicial de Meloidogyne sp. en el cultivo del tomate. El estudio se realizó en León, Nicaragua en el año 2011. Las variables medidas fueron número de nematodos al trasplante y al momento de la cosecha, altura de la planta al momento de la madurez fisiológica y el rendimiento en kilogramos. La extracción de nematodos se realizó mediante el método de Baermann modificado. En el estudio, la densidad inicial (Pi presentó una correlación lineal positiva con la densidad final (Pf. Sin embargo, se observó que cuando la Pi era igual a 400 nematodos/100 g de suelo, el factor de reproducción se incrementaba a 3,64; por el contrario, cuando la Pi era igual a 700 nematodos/100 g de suelo, el factor de reproducción se reducía a 2,48. La Pi se correlacionó inversamente con el peso de frutos y altura de las plantas. Plantas con 200 nematodos/100 g de suelo presentaban peso de frutos de 2,19 kg y altura de 153,20 cm en comparación con 0,93 kg y 135,24 cm en plantas con 600 nematodos/100 g de suelo. Existió una correlación positiva entre Pi y Pf de Meloidogy- ne sp. en el tomate. Las poblaciones de este nematodo, se correlacionaron inversamente con las variables altura y peso de los frutos.

Control of Pathogenicity Root-Knot Nematode (Meloidogyne Javanica by Earthworm Eisenia Feoetida-Based Products in Greenhouse

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M. Rostami

2016-06-01

Full Text Available Introduction: Biocontrol of nematode agents in order to decrease the hazardous impacts of chemical pesticide application including problems of public health and environmental pollution is apriority. In this study, solid (Vermicompost and liquid products (Liquid Vermicompost, Vermiwash and Coelomic fluidof the earthworm species Eisenia fetida were tested against root-knot nematode, Meloidogyne javanica in greenhouse conditions. Materials and Methods: In this study, Solid (Vermicompost and Liquid products(Wormtea, Vermiwash, Coelomic fluid erthworms (Eisenia foetida were tested against Meloidogyne javanica and also the effect of Vermicompost was evaluated on Pathogenicity of various nematode initial inoculum in two stage greenhouse conditions. Earthworm-based products (Vermicompost, Wormtea, Vermiwash and Coelomic fluid were added to tomato pots. Various treatments of liquid as well as solid products and their combination were used in the greenhouse trial. The first Stage greenhouse experiment- Tomato seeds grown in 2 kg sterilized soil. In the treatments having Vermicompost, pots incorporated with 200 gr of this compost homogeneously mixed with soil. After plants reached at two leaf stage, to study the effects of liquid products (Wormtea, Vermiwash, and Coelomic fluid they added to the pots (500cc along with the irrigation water every week and after of 4 leaf stage, 5000 nematode eggs and larva inoculated to the tomato host plants. 90 days after nematode inoculation, plant and nematode growth indices separately measured and compared. The experiment conducted based on completely randomized design having four replicates. The second stage greenhouse experiment- Tomato seeds grown in 2 kg sterilized soil. In the treatments, pots incorporated with 200 gr of this compost homogeneously mixed with soil. After of 4 leaf stage, 0,1000,2000,4000 and 10000 nematode eggs and larva inoculated to the tomato host plants. 90 days after nematode inoculation, plant

Nematode neuropeptides as transgenic nematicides.

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Neil D Warnock

2017-02-01

Full Text Available Plant parasitic nematodes (PPNs seriously threaten global food security. Conventionally an integrated approach to PPN management has relied heavily on carbamate, organophosphate and fumigant nematicides which are now being withdrawn over environmental health and safety concerns. This progressive withdrawal has left a significant shortcoming in our ability to manage these economically important parasites, and highlights the need for novel and robust control methods. Nematodes can assimilate exogenous peptides through retrograde transport along the chemosensory amphid neurons. Peptides can accumulate within cells of the central nerve ring and can elicit physiological effects when released to interact with receptors on adjoining cells. We have profiled bioactive neuropeptides from the neuropeptide-like protein (NLP family of PPNs as novel nematicides, and have identified numerous discrete NLPs that negatively impact chemosensation, host invasion and stylet thrusting of the root knot nematode Meloidogyne incognita and the potato cyst nematode Globodera pallida. Transgenic secretion of these peptides from the rhizobacterium, Bacillus subtilis, and the terrestrial microalgae Chlamydomonas reinhardtii reduce tomato infection levels by up to 90% when compared with controls. These data pave the way for the exploitation of nematode neuropeptides as a novel class of plant protective nematicide, using novel non-food transgenic delivery systems which could be deployed on farmer-preferred cultivars.

Synthesis, Antimicrobial, Antioxidant and Nematicidal Activity of (2E,4E)-5-(Benzo(d) (1,3)dioxol-5yl)penta-2,4-dienamides

International Nuclear Information System (INIS)

Wahab, A.; Sultana, A.; Sherwani, S. K.; Perveen, Z.; Khan, K. M.; Karim, A.; Taha, M.

2015-01-01

The amides of piperic acid have been synthesized via the condensation of piperic acid with amines. The structural characterization was done by IR, 1H-NMR, EI-MS and elemental analysis. The amides 3a-3o were evaluated for their biological activity. It has been found that among others the newly synthesized compound 3f, 3k, 3m, and 3o have great potential against root-knot nematode Meloidogyne incognita that usually affect tomato crop. These compounds exhibited 92, 96, 82 and 95% mortality rate at lethal concentration (LC50) 4.4, 3.4, 4.5 and 3.5 mg/mL, respectively. Conventionally used nematicide furadan was taken as standard. Compound 3h, 3c and, 3j exhibited significant anti-oxidant activities against 1,1-diphenylpicrylhydrazil (DPPH) radical with 80, 70 and 72% inhibition (EC50 = 625, 937 and 937.5 micro g/mL), respectively. Ascorbic acid was used as standard. When tested for antimicrobial activity 3m was found to be the most active one showing zone of inhibition in the range of 18-30 mm against all tested microbial strains. Good biological activities of synthetic amides indicate their ability to behave as a good antimicrobial and nematicidal agent. (author)

Root-knot nematode management in double-cropped plasticulture vegetables.

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Desaeger, J A; Csinos, A S

2006-03-01

Combination treatments of chisel-injected fumigants (methyl bromide, 1,3-D, metam sodium, and chloropicrin) on a first crop, followed by drip-applied fumigants (metam sodium and 1,3-D +/- chloropicrin) on a second crop, with and without oxamyl drip applications were evaluated for control of Meloidogyne incognita in three different tests (2002 to 2004) in Tifton, GA. First crops were eggplant or tomato, and second crops were cantaloupe, squash, or jalapeno pepper. Double-cropped vegetables suffered much greater root-knot nematode (RKN) pressure than first crops, and almost-total yield loss occurred when second crops received no nematicide treatment. On a first crop of eggplant, all fumigants provided good nematode control and average yield increases of 10% to 15 %. On second crops, higher application rates and fumigant combinations (metam sodium and 1,3-D +/- chloropicrin) improved RKN control and increased yields on average by 20% to 35 % compared to the nonfumigated control. Oxamyl increased yields of the first crop in 2003 on average by 10% to 15% but had no effect in 2004 when RKN failed to establish itself. On double-cropped squash in 2003, oxamyl following fumigation provided significant additional reduction in nematode infection and increased squash yields on average by 30% to 75%.

Sustainable management of root-knot disease of tomato by neem cake and Glomus fasciculatum

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Rose Rizvi

2015-12-01

Full Text Available A pot experiment was conducted during winter season of 2009–2010 in the department of Botany, AMU, Aligarh, India, to determine the nematicidal potential of organic matter, neem cake at third level of dose, and bioagent, Glomus fasciculatum in terms of various growth parameters of tomato, when inoculated individually as well as concomitantly with respect to root-knot development. Neem cake and G. fasciculatum showed potential for sustainable management while providing nutrient sources for proper plant growth. Disease intensity of root-knot nematode decreased while increasing the doses of neem cake along with the G. fasciculatum. Chlorophyll contents have been found to be increased in single and combined application as well. There is a progressive increase in growth parameters raised in soil amended with 10, 20, and 30 g neem cake/kg soil and inoculated with G. fasciculatum. Significant improvement in the plant growth was observed when G. fasciculatum and neem cake were inoculated simultaneously. Neem cake plus G. fasciculatum reduced the nematodes’ multiplication and root-galling, and increased the plant growth of tomato as compared to unamended and Meloidogyne incognita-inoculated plants. Mycorrhyzation and agronomic parameters were increased due to application of G. fasciculatum alone, but enhanced further when inoculated with neem cake.

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

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M. Y. Jada

2011-01-01

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

Atração e penetração de Meloidogyne javanica e Heterodera glycines em raízes excisadas de soja Attraction and penetration of Meloidogyne javanica and Heterodera glycines in excised soybean roots

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Hercules Diniz Campos

2011-09-01

Full Text Available Com vista ao estudo de atração e penetração de Meloidogyne javanica (Treub Chitwood e Heterodera glycines (Ichinoe em soja (Glycine max L., desenvolveu-se uma técnica empregando-se segmento de raiz com 2cm de comprimento. Nos segmentos de raiz de soja infectados, observou-se que a penetração de juvenis de segundo estádio (J2 de M. javanica ocorre pela coifa seguida de migração entre os feixes vasculares do cilindro central. Juvenis de H. glycines penetraram, aproximadamente, 15mm da coifa. A região seccionada da raiz de soja atraiu três vezes mais J2 de M. javanica do que a região da coifa, mas esta não foi tão atrativa para J2 de H. glycines. A obstrução conjunta da coifa e do local seccionado reduziu (83% a penetração de J2, tanto de M. javanica quanto de H. glycines. Quando apenas um desses locais foi obstruído, a outra extremidade livre compensou o processo atrativo. Portanto, as substâncias atrativas são liberadas por essas extremidades. A penetração de J2 de M. javanica foi maior no segmento de raiz quando comparada com a plântula intacta de soja. Entretanto, os J2 de H. glycines penetraram menos em segmentos de raiz e em plântulas sem folhas, quando comparados com plântulas intactas e com as seccionadas no colo. Portanto, na cultivar de soja "Embrapa 20", a atração e os locais de penetração de J2 de H. glycines e M. javanica são diferenciados. Esta técnica poderá ser útil nos estudos de atração e penetração de outros nematoides endoparasitas.To study the attraction and penetration of Meloidogyne javanica (Treub Chitwood and Heterodera glycines (Ichinoe in soybean (Glycine max L., a technique using 2-cm long root segments was developed. In infected soybean root segments penetration of second stage juveniles (J2 of M. javanica occured through the root cap following migration between the vascular bundles of the central cylinder. Juveniles of H. glycines penetrated about 15mm from the root cap. The cut

Zinc and glycerol enhance the production of nematicidal compounds in vitro and improve the biocontrol of Meloidogyne javanica in tomato by fluorescent pseudomonads.

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Siddiqui, I A; Shaukat, S S

2002-01-01

To assess the effects of various carbon and mineral sources on the nematicidal potential of biocontrol inoculants of Pseudomonas aeruginosa IE-6S+ and Ps. fluorescens CHA0 under laboratory and glasshouse conditions. Culture filtrates of strains IE-6S+ and CHA0, cultured in nutrient yeast extract broth, caused substantial mortality of the juveniles of Meloidogyne javanica. The nematicidal activities of the culture filtrates were altered after amendment with various carbon and mineral sources. Soil amendment with zinc alone or in combination with glycerol improved the biocontrol efficacy against root-knot nematode, promoted tomato plant growth and enhanced bacterial rhizosphere and endophytic colonization. Appropriate quantities of glycerol and zinc alone or in combination enhance the nematicidal activity of Ps. aeruginosa and Ps. fluorescens. Glucose reduces the activity of these bacteria against nematodes. Minerals and carbon sources are appealing because they are easy and economical to provide during liquid fermentation of inoculants or as fertilizer amendments to improve the biocontrol activity of indigenous and introduced bacteria.

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

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Leandro Grassi de Freitas

2009-10-01

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

Phylogenetic Analysis of Pasteuria penetrans by 16S rRNA Gene Cloning and Sequencing.

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Anderson, J M; Preston, J F; Dickson, D W; Hewlett, T E; Williams, N H; Maruniak, J E

1999-09-01

Pasteuria penetrans is an endospore-forming bacterial parasite of Meloidogyne spp. This organism is among the most promising agents for the biological control of root-knot nematodes. In order to establish the phylogenetic position of this species relative to other endospore-forming bacteria, the 16S ribosomal genes from two isolates of P. penetrans, P-20, which preferentially infects M. arenaria race 1, and P-100, which preferentially infects M. incognita and M. javanica, were PCR-amplified from a purified endospore extraction. Universal primers for the 16S rRNA gene were used to amplify DNA which was cloned, and a nucleotide sequence was obtained for 92% of the gene (1,390 base pairs) encoding the 16S rDNA from each isolate. Comparison of both isolates showed identical sequences that were compared to 16S rDNA sequences of 30 other endospore-forming bacteria obtained from GenBank. Parsimony analyses indicated that P. penetrans is a species within a clade that includes Alicyclobacillus acidocaldarius, A. cycloheptanicus, Sulfobacillus sp., Bacillus tusciae, B. schlegelii, and P. ramosa. Its closest neighbor is P. ramosa, a parasite of Daphnia spp. (water fleas). This study provided a genomic basis for the relationship of species assigned to the genus Pasteuria, and for comparison of species that are parasites of different phytopathogenic nematodes.

Divergent expression of cytokinin biosynthesis, signaling and catabolism genes underlying differences in feeding sites induced by cyst and root-knot nematodes.

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Dowd, Carola D; Chronis, Demosthenis; Radakovic, Zoran S; Siddique, Shahid; Schmülling, Thomas; Werner, Tomáš; Kakimoto, Tatsuo; Grundler, Florian M W; Mitchum, Melissa G

2017-10-01

Cyst and root-knot nematodes are obligate parasites of economic importance with a remarkable ability to reprogram root cells into unique metabolically active feeding sites. Previous studies have suggested a role for cytokinin in feeding site formation induced by these two types of nematodes, but the mechanistic details have not yet been described. Using Arabidopsis as a host plant species, we conducted a comparative analysis of cytokinin genes in response to the beet cyst nematode (BCN), Heterodera schachtii, and the root-knot nematode (RKN), Meloidogyne incognita. We identified distinct differences in the expression of cytokinin biosynthesis, catabolism and signaling genes in response to infection by BCN and RKN, suggesting differential manipulation of the cytokinin pathway by these two nematode species. Furthermore, we evaluated Arabidopsis histidine kinase receptor mutant lines ahk2/3, ahk2/4 and ahk3/4 in response to RKN infection. Similar to our previous studies with BCN, these lines were significantly less susceptible to RKN without compromising nematode penetration, suggesting a requirement of cytokinin signaling in RKN feeding site formation. Moreover, an analysis of ahk double mutants using CycB1;1:GUS/ahk introgressed lines revealed contrasting differences in the cytokinin receptors mediating cell cycle activation in feeding sites induced by BCN and RKN. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Damage-associated responses of the host contribute to defence against cyst nematodes but not root-knot nematodes.

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Shah, Syed Jehangir; Anjam, Muhammad Shahzad; Mendy, Badou; Anwer, Muhammad Arslan; Habash, Samer S; Lozano-Torres, Jose L; Grundler, Florian M W; Siddique, Shahid

2017-12-16

When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in plant-nematode interactions remain unexplored. Here, we characterized the role of a group of cell wall receptor proteins in Arabidopsis, designated as polygalacturonase-inhibiting proteins (PGIPs), during infection with the cyst nematode Heterodera schachtii and the root-knot nematode Meloidogyne incognita. PGIPs are encoded by a family of two genes in Arabidopsis, and are involved in the formation of active OG elicitors. Our results show that PGIP gene expression is strongly induced in response to cyst nematode invasion of roots. Analyses of loss-of-function mutants and overexpression lines revealed that PGIP1 expression attenuates infection of host roots by cyst nematodes, but not root-knot nematodes. The PGIP1-mediated attenuation of cyst nematode infection involves the activation of plant camalexin and indole-glucosinolate pathways. These combined results provide new insights into the molecular mechanisms underlying plant damage perception and response pathways during infection by cyst and root-knot nematodes, and establishes the function of PGIP in plant resistance to cyst nematodes. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

A distinct role of pectate lyases in the formation of feeding structures induced by cyst and root-knot nematodes.

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Wieczorek, K; Elashry, A; Quentin, M; Grundler, F M W; Favery, B; Seifert, G J; Bohlmann, H

2014-09-01

Pectin in the primary plant cell wall is thought to be responsible for its porosity, charge density, and microfibril spacing and is the main component of the middle lamella. Plant-parasitic nematodes secrete cell wall-degrading enzymes that macerate the plant tissue, facilitating the penetration and migration within the roots. In sedentary endoparasitic nematodes, these enzymes are released only during the migration of infective juveniles through the root. Later, nematodes manipulate the expression of host plant genes, including various cell wall enzymes, in order to induce specific feeding sites. In this study, we investigated expression of two Arabidopsis pectate lyase-like genes (PLL), PLL18 (At3g27400) and PLL19 (At4g24780), together with pectic epitopes with different degrees of methylesterification in both syncytia induced by the cyst nematode Heterodera schachtii and giant cells induced by the root-knot nematode Meloidogyne incognita. We confirmed upregulation of PLL18 and PLL19 in both types of feeding sites with quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and in situ RT-PCR. Furthermore, the functional analysis of mutants demonstrated the important role of both PLL genes in the development and maintenance of syncytia but not giant cells. Our results show that both enzymes play distinct roles in different infected root tissues as well as during parasitism of different nematodes.

Effect of application timing and method on efficacy and phytotoxicity of 1,3-D, chloropicrin and metam-sodium combinations in squash plasticulture.

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Desaeger, Johan A; Seebold, Kenneth W; Csinos, Alex S

2008-03-01

Metam-sodium, 1,3-dichloropropene (1,3-D) and chloropicrin are widely used soil fumigants. Combined application of metam-sodium and 1,3-D + chloropicrin is intended to improve efficacy and broaden spectrum of control, but little is known about the effect on crop safety. This study aimed to evaluate the effects of application timing of fumigant combinations on soilborne pest and disease control (nematodes, soil fungi and weeds) and growth of squash. Two separate tests with chisel-injected and drip-applied fumigant combinations and plant-back times ranging from 1 to 4 weeks were conducted in Tifton, GA, USA, in spring and fall 2002. Fumigant combinations using 1,3-D, chloropicrin and metam-sodium were as effective as methyl bromide in controlling Meloidogyne incognita (Kofoid & White) Chitwood, Pythium irregulare Buis., Rhizoctonia solani Kühn and Cyperus esculentus L. Chisel-applied combinations were more effective in terms of root-knot nematode control than drip-applied combinations. Root-knot nematode reduced squash yields by up to 60%. Phytotoxicity problems and lower yields were observed during spring, especially following 1,3-D + chloropicrin and when plant-back periods were shorter. The main problem with fumigant alternatives to methyl bromide may not be reduced efficacy but, in particular for 1,3-D products, loss of flexibility in terms of longer plant-back periods. (c) 2008 Society of Chemical Industry.

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

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Davies, Keith G

2009-01-01

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

Tomato progeny inherit resistance to the nematode Meloidogyne javanica linked to plant growth induced by the biocontrol fungus Trichoderma atroviride.

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Medeiros, Hugo Agripino de; Araújo Filho, Jerônimo Vieira de; Freitas, Leandro Grassi de; Castillo, Pablo; Rubio, María Belén; Hermosa, Rosa; Monte, Enrique

2017-01-10

Root-knot nematodes (RKN) are major crop pathogens worldwide. Trichoderma genus fungi are recognized biocontrol agents and a direct activity of Trichoderma atroviride (Ta) against the RKN Meloidogyne javanica (Mj), in terms of 42% reduction of number of galls (NG), 60% of number of egg masses and 90% of number of adult nematodes inside the roots, has been observed in tomato grown under greenhouse conditions. An in vivo split-root designed experiment served to demonstrate that Ta induces systemic resistance towards Mj, without the need for the organisms to be in direct contact, and significantly reduces NG (20%) and adult nematodes inside tomato roots (87%). The first generation (F1) of Ta-primed tomato plants inherited resistance to RKN; although, the induction of defenses occurred through different mechanisms, and in varying degrees, depending on the Ta-Mj interaction. Plant growth promotion induced by Ta was inherited without compromising the level of resistance to Mj, as the progeny of Ta-primed plants displayed increased size and resistance to Mj without fitness costs. Gene expression results from the defense inductions in the offspring of Ta-primed plants, suggested that an auxin-induced reactive oxygen species production promoted by Ta may act as a major defense strategy during plant growth.

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

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Zainab M. Ahmed

2012-12-01

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

Efeito da mucuna e amendoim em rotação com algodoeiro A study on crop rotation for cotton using velvet bean and peanut

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Carlos A. M. Ferraz

1977-01-01

Full Text Available O efeito da rotação de mucuna (Stizolobium atterrimum Piper & Tracy e amendoim (Arachis hypogaea L. e de duas variedades comerciais de algodoeiro, IAC RM3 e IAC 12-2 (Gossypium hirsutum L. foi estudado nos anos agrícolas de 1967/68 a 1972/73. Foram instalados dois ensaios, um em Presidente Bernardes, com fusariose, em solo podzolizado de Lins e Marília var. Lins naturalmente infectado por Fusarium oxysporumf. vasinfectum e o nematóide causador de galhas Meloidogyne incognita (Kofoid & White Chitwood, e outro em Presidente Venceslau, sem fusariose, em latossolo vermelho-escuro f. arenosa não infectado. A variedade comercial IAC RM3 é resistente e a IAC 12-2 é suscetível à fusariose. Para a análise estatística dos dados adotou-se o esquema de parcelas subdivididas, com seis repetições, tendo sido consideradas como parcelas as variedades de algodoeiro IAC RM3 e IAC 12-2, plantadas em 1968/69, 1970/71, 1971/72 e 1972/73, e como subparcelas as culturas em rotação, mucuna, amendoim e as variedades de algodoeiro IAC RM3 e IAC 12-2, plantadas nos anos-agrícolas de 1967/68 e 1969/70. Em solos com fusariose, em 1968/69, e em solos sem fusariose, no ano agrícola de 1970/71, destacou-se o efeito da rotação com mucuna, seguida da rotação com amendoim. Depois do plantio consecutivo de algodoeiro durante três anos (1970/71 a 1972/73, cessaram praticamente os efeitos da rotação para os dois casos. Houve aumento do teor de potássio após o primeiro ano de rotação, sendo maior para a mucuna.The effect of rotation of velvet bean (Stizolobium atterrimum Piper & Tracy, and peanut (Arachis hypogaea L. with two comercial varieties of cotton IAC RM3 and IAC 12-2 (Gossypium hirsutum L. was studied during 1967/68 to 1972/73. One experiment was conducted in a soil naturally infected by Fusarium oxysporum f. vasinfectum (Atk. Snyder & Hansen and by Meloidogyne incognita (Kofoid & White Chitwood, (President Bernardes, State of São Paulo, in

Biological control of wilt disease complex on tomato crop caused by Meloidogyne javanica and Fusarium oxysporum f.sp. lycopersici by Verticillium leptobactrum.

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Hajji-Hedfi, Lobna; Regaieg, Hajer; Larayedh, Asma; Chihani, Noura; Horrigue-Raouani, Najet

2017-09-23

The efficacy of Verticillium leptobactrum isolate (HR1) was evaluated in the control of root-knot nematode and Fusarium wilt fungus under laboratory and greenhouse conditions. Five concentrations of V. leptobactrum (HR1) isolate were tested for their nematicidal and fungicidal activities against Meloidogyne javanica and Fusarium oxysporum f.sp. lycopersici in vitro. Laboratory trials showed that mycelium growth inhibition of Fusarium wilt fungus was correlated to the increase of the concentration of culture filtrate. All dilutions showed efficiency in reducing the growth of Fusarium oxysporum f.sp. lycopersici. The greatest nematicidal activity was observed at 50, 75, and 100% filtrate dilutions. The egg hatching percentage reached 42%, and the juvenile's corrected mortality registered 90% for the above treatments. In greenhouse experiment, the biocontrol agent fungus enhanced significantly tomato growth components (height and weight of plant and root). The multiplication rate of root-knot nematode and the Fusarium wilt disease incidence declined significantly with soil application of V. leptobactrum as with chemical treatments. The isolate HR1 was efficient to control wilt disease complex caused by M. javanica and Fusarium oxysporum f.sp. lycopersici.

DENSIDAD CRÍTICA DE Meloidogyne exigua EN PLANTAS DE ALMÁCIGO DE CAFÉ VARIEDAD CATURRA

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Mainor Rojas

2013-01-01

Full Text Available El objetivo del estudio fue evaluar el efecto de densidad creciente de Meloidogyne exigua sobre el desarrollo de plantas de almácigo. Se trasplantaron plántulas de café variedad caturra a bolsas de polietileno con 1335 cm3 de sustrato desinfectado, para establecer un ensayo con diseño de bloques completos al azar, con 8 repeticiones. Los tratamientos aplicados consistieron de poblaciones iniciales (Pi de 0; 0,125; 0,25; 0,5; 1; 2; 4; 8; 16; 32 y 64 huevos+J2/ cm3 de sustrato, aplicadas un mes después del trasplante. El modelo y=m+(1-m ZP-T aplicado 234 días después del trasplante para la altura, diámetro, número de nudos y peso fresco aéreo, indicó que el límite de tolerancia (T fue de 0,66; 0,06; 0,13 y 0,88 huevos+J2/cm3, respectivamente; la producción mínima relativa (m fue de 0,79; 0,79; 0,33 y 0,54 respectivamente, a Pi iguales o mayores a 64 huevos+J2/cm3. El índice de agallas alcanzó el máximo a partir de una Pi de 2; el pico máximo de nematodos en el suelo y las raíces se alcanzó con Pi entre 2 y 4; mientras la tasa máxima de reproducción fue de 114 con Pi de 0,125. Se concluyó que la densidad crítica fue cercana a cero huevos/cm3 de sustrato como población inicial, y que el almácigo se debe desarrollar libre de nematodos, ya que aún con Pi bajas se puede alcanzar la máxima población en corto tiempo.

The effect of different initial densities of nematode (Meloidogyne javanica) on the build-up of Pasteuria penetrans population.

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Darban, Daim Ali; Pathan, Mumtaz Ali; Bhatti, Abdul Ghaffar; Maitelo, Sultan Ahmed

2005-02-01

Pasteuria penetrans will build-up faster where there is a high initial nematode density and can suppress root-knot nematode populations in the roots of tomato plants. The effect of different initial densities of nematode (Meloidogyne javanica) (150, 750, 1500, 3000) and P. penetrans infected females (F1, F3) densities (F0=control and AC=absolute control without nematode or P. penetrans inoculum) on the build-up of Pasteuria population was investigated over four crop cycles. Two major points of interest were highlighted. First, that within a confined soil volume, densities of P. penetrans can increase >100 times within 2 or 3 crop cycles. Second, from a relatively small amount of spore inoculum, infection of the host is very high. There were more infected females in the higher P. penetrans doses. The root growth data confirms the greater number of females in the controls particularly at the higher inoculum densities in the third and fourth crops. P. penetrans generally caused the fresh root weights to be higher than those in the control. P. penetrans has shown greater reduction of egg masses per plant at most densities. The effects of different initial densities of M. javanica and P. penetrans on the development of the pest and parasite populations were monitored. And no attempt was made to return the P. penetrans spores to the pots after each crop so the build-up in actual numbers of infected females and spores under natural conditions may be underestimated.

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

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Maryluce Albuquerque da Silva Campos

2017-06-01

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

Trichoderma harzianum enhances the production of nematicidal compounds in vitro and improves biocontrol of Meloidogyne javanica by Pseudomonas fluorescens in tomato.

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Siddiqui, I A; Shaukat, S S

2004-01-01

To determine the influence of soil-borne fungus Trichoderma harzianum on the biocontrol performance of Pseudomonas fluorescens strain CHA0 and its 2,4-diacetylphloroglucinol (DAPG) overproducing derivative CHA0/pME3424 against Meloidogyne javanica. Amendment of the culture filtrate (CF) or methanol extract of the CF of a T. harzianum strain Th6 to P. fluorescens growth medium enhanced the production of nematicidal compound(s) by bacterial inoculants in vitro. In addition, bacteria overwhelmingly expressed phl'-'lacZ reporter gene when the medium was amended with CF of T. harzianum. Pseudomonas fluorescens and T. harzianum applied together in unsterilized sandy loam soil caused greater reduction in nematode population densities in tomato roots. Trichoderma harzianum improves root-knot nematode biocontrol by the antagonistic rhizobacterium P. fluorescens both in vitro and under glasshouse conditions. The synergistic effect of T. harzianum on the production of nematicidal compound(s) critical in biocontrol may improve the efficacy of biocontrol bacteria against plant-parasitic nematodes. Considering the inconsistent performance of the biocontrol agents under field conditions, application of a mixture of compatible T. harzianum and P. fluorescens would more closely mimic the natural situation and might broaden the spectrum of biocontrol activity with enhanced efficacy and reliability of control.

The diverse nematicidal properties and biocontrol efficacy of Bacillus thuringiensis Cry6A against the root-knot nematode Meloidogyne hapla.

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Yu, Ziquan; Xiong, Jing; Zhou, Qiaoni; Luo, Haiyan; Hu, Shengbiao; Xia, Liqiu; Sun, Ming; Li, Lin; Yu, Ziniu

2015-02-01

Cry6A toxin from Bacillus thuringiensis is a representative nematicidal crystal protein with a variety of nematicidal properties to free-living nematode Caenorhabditis elegans. Cry6A shares very low homology and different structure with Cry5B, another representative nematicidal crystal protein, and probably acts in a distinct pathway. All these strongly indicate that Cry6A toxin is likely a potent candidate for nematicide. The present study dealt with global investigation to determine the detrimental impacts of Cry6Aa2 toxin on Meloidogyne hapla, a root-knot nematode, and evaluated its biocontrol efficacy in pot experiment. Obtained results indicated that Cry6Aa2 toxin exhibits obvious toxicity to second-stage juvenile of M. hapla, and significantly inhibits egg hatch, motility, and penetration to host plant. Pot experiment suggested that soil drenching with spore-crystal mixture of Cry6Aa2 can clearly lighten the disease of root-knot nematode, including reduction of galling index and egg masses on host plant root, decreasing final population of nematode in soil. Moreover, application of Cry6Aa2 can obviously promote plant growth. These results demonstrated that Cry6Aa2 toxin is a promising nematicidal agent, and possesses great potential in plant-parasitic nematode management and construction of transgenic crop with constant resistance to nematode. Copyright © 2015 Elsevier Inc. All rights reserved.

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

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

2015-11-25

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

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

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

2016-01-01

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

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

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Neha Khan

2015-06-01

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

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

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

1995-01-01

Single populations of Meloidogyne arenaria races 1 (MA1) and 2 (MA2) and M. hapla (MH), and mixed populations of MA1 + MA2 and MA1 + MH with four inoculum levels of eggs were tested on peanut cv. 'Florigiant' and M. incognita-resistant tobacco cv. 'McNair 373' in a greenhouse experiment. Root infection, female development, and reproduction of MA2 on peanut and MA1 on resistant tobacco were limited at 2 and 6 weeks. MA1, MH, and MA1 + MH on peanut had similar root infection (total parasitic forms per root unit) at both 2 and 6 weeks, and similar female development and reproduction potentials at 6 weeks. MA2 tended to depress root infection, female development, and reproduction of MA1 on peanut. MH had little effect on MA1 on this crop. On tobacco, MA2 population had greater incidence of root infection than did MH at 2 weeks. The two nematode species had similar development in roots at 6 weeks. All of these processes were restricted when either MA2 or MH was present together with MA1. As initial inoculum level of parasitically fit populations increased, relative infection ratio on both peanut and tobacco, and reproduction factor on peanut decreased. Populations that had high infection incidence and reproduction rates induced greater root galling than did other populations. Root galling was suppressed in the presence of antagonistic response between nematode populations. PMID:19277277

A sulfonic anhydride derivative from dibenzyl trisulphide with agro-chemical activities.

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Williams, L A D; Vasquez, E; Klaiber, I; Kraus, W; Rosner, H

2003-06-01

In the present study, the biologically active natural product dibenzyl trisulphide (DTS) which was previously isolated from the sub-tropical shrub Petiveria alliacea was transformed to methyl benzyl sulphonic anhydride (MBSA) using a "one pot" transformation method. The anhydride was evaluated for anti-microbial activities on the bacteria, Bacillus subtilis and Pseudomonas fluorescens and found to be 2.5 fold more effective than the commercial agents isoniazid and ampicillin in inhibiting the growth of B. subtilis, while on P. fluorescens it was 2.5, 5.0 and 10.0 fold more inhibitory than isoniazid, ampicillin and dibenzyl trisulphide, respectively. DTS was inactive on B. subtillis. The MIC value (microgram/spot) found for DTS on the plant pathogenic fungus, Cladosporium cucumerinum was 5.0 microgram/spot, while MBSA gave a value of 0.1 microgram/spot, compared with 1.25 and 0.16 microgram/spot for the commercial agents ketoconazole and nystatin, respectively. On the larval nematode (Meloidogyne incognita) MBSA inflicted 97.72% and 57.47% Abbotts nematicidal activities at 125.0 and 62.5 ppm, respectively, while DTS had no effect at 125.0 ppm. Nematodes which were immobilized by the low concentrations of MBSA were unable to re-activate when exposed to 10.0 ppm picrotoxin, thus suggesting that the anhydride nematicidal activity is independent of the GABA-ergic neurophysiological pathway.MBSA demonstrated a strong dose dependent radicular suppression effect (r=0.984), on the radicles of Latuca sativa germinating seeds. DTS was weakly active.

The complete mitochondrial genome of Meloidogyne graminicola (Tylenchina: a unique gene arrangement and its phylogenetic implications.

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Longhua Sun

Full Text Available Meloidogyne graminicola is one of the most economically important plant parasitic-nematodes (PPNs. In the present study, we determined the complete mitochondrial (mt DNA genome sequence of this plant pathogen. Compared with other PPNs genera, this genome (19,589 bp is only slightly smaller than that of Pratylenchus vulnus (21,656 bp. The nucleotide composition of the whole mtDNA sequence of M. graminicola is significantly biased toward A and T, with T being the most favored nucleotide and C being the least favored. The A+T content of the entire genome is 83.51%. The mt genome of M. graminicola contains 36 genes (lacking atp8 that are transcribed in the same direction. The gene arrangement of the mt genome of M. graminicola is unique. A total of 21 out of 22 tRNAs possess a DHU loop only, while tRNASer(AGN lacks a DHU loop. The two large noncoding regions (2,031 bp and 5,063 bp are disrupted by tRNASer(UCN. Phylogenetic analysis based on concatenated amino acid sequences of 12 protein-coding genes support the monophylies of the three orders Rhabditida, Mermithida and Trichinellida, the suborder Rhabditina and the three infraorders Spiruromorpha, Oxyuridomorpha and Ascaridomorpha, but do not support the monophylies of the two suborders Spirurina and Tylenchina, and the three infraorders Rhabditomorpha, Panagrolaimomorpha and Tylenchomorpha. The four Tylenchomorpha species including M. graminicola, P. vulnus, H. glycines and R. similis from the superfamily Tylenchoidea are placed within a well-supported monophyletic clade, but far from the other two Tylenchomorpha species B. xylophilus and B. mucronatus of Aphelenchoidea. In the clade of Tylenchoidea, M. graminicola is sister to P. vulnus, and H. glycines is sister to R. similis, which suggests root-knot nematodes has a closer relationship to Pratylenchidae nematodes than to cyst nematodes.

Differential impact of some Aspergillus species on Meloidogyne javanica biocontrol by Pseudomonas fluorescens strain CHA0.

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Siddiqui, I A; Shaukat, S S; Khan, A

2004-01-01

The aim was to determine the influence of some Aspergillus species on the production of nematicidal agent(s) in vitro and biocontrol of Meloidogyne javanica in tomato by Pseudomonas fluorescens strains CHA0 and CHA0/pME3424. Six species of Aspergillus, isolated from the rhizosphere of certain crops, produced a variety of secondary metabolites in vitro. Culture filtrate (CF) obtained from Ps. fluorescens strain CHA0 and its2,4-diacetylphloroglucinol overproducing mutant CHA0/pME3424 grown in King's B liquid medium caused significant mortality of M. javanica juveniles in vitro. Bacterial growth medium amended with CF of A. niger enhanced nematicidal and beta-galactosidase activities of fluorescent pseudomonads while A. quadrilineatus repressed such activities. Methanol or ethyl acetate extracts of the CF of A. niger markedly optimized bacterial efficacy to cause nematode deaths while hexane extract of the fungus had no influence on the nematicidal activity of the bacterial strains. A. niger applied alone or in conjunction with the bacterial inoculants inhibited root-knot nematode galling in tomato. On the other hand, A. quadrilineatus used alone or together with CHA0 did not inhibit nematode galling but when used in combination with strain CHA0/pME3424 did reduce galling intensity. Aspergillus niger enhances the production of nematicidal compounds by Ps. fluorescensin vitro and improves biocontrol potential of the bacterial inoculants in tomato while A. quadrilineatus reduces bacterial performance to suppress root-knot nematodes. Rhizosphere harbours a variety of micro-organisms including bacteria, fungi and viruses. Aspergillus species are ubiquitous in most agricultural soils and generally produce a variety of secondary metabolites. Such metabolites synthesized by Aspergillus species may influence the production of nematicidal agents and subsequent biocontrol performance of the bacterial inoculants against plant-parasitic nematodes. This fact needs to be taken into

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

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Bélair, G.; Benoit, D. L.

1996-01-01

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

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

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Fengjuan Zhang

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

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

NARCIS (Netherlands)

Martínez-Medina, Ainhoa; Fernandez, Ivan; Lok, Gerrit B; Pozo, María J; Pieterse, Corné M J|info:eu-repo/dai/nl/113115113; Van Wees, Saskia C M|info:eu-repo/dai/nl/185445373

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

Evaluation of Pochonia chlamydosporia and Purpureocillium lilacinum for Suppression of Meloidogyne enterolobii on Tomato and Banana.

Science.gov (United States)

Silva, Silas D; Carneiro, Regina M D G; Faria, Marcos; Souza, Daniela A; Monnerat, Rose G; Lopes, Rogerio B

2017-03-01

Meloidogyne enterolobii is one of the most important root-knot nematode in tropical regions, due to its ability to overcome resistance mechanisms of a number of host plants. The lack of new and safe active ingredients against this nematode has restricted control alternatives for growers. Egg-parasitic fungi have been considered as potential candidates for the development of bionematicides. In tissue culture plates, Pochonia chlamydosporia (var. catenulata and chlamydosporia ) and Purpureocillium lilacinum strains were screened for their ability to infect eggs of the root-knot nematode M. enterolobii on water-agar surfaces. Reduction in the hatching of J2 varied from 13% to 84%, depending on strain. The more efficacious strains reduced hatchability of J2 by 57% to 84% when compared to untreated eggs, but average reductions were only 37% to 55% when the same strains were applied to egg masses. Combinations of fungal isolates (one of each species) did not increase the control efficacy in vitro. In experiments in which 10,000 nematode eggs were inoculated per plant, reductions in the number of eggs after 12 months were seen in three of four treatments in banana plants, reaching 34% for P. chlamydosporia var. catenulata . No significant reductions were seen in tomato plants after 3 mon. In another experiment with tomato plants using either P. chlamydosporia var. catenulata or P. lilacinum , the number of eggs was reduced by 34% and 44%, respectively, when initial infestation level was low (500 nematode eggs per plant), but tested strains were not effective under a moderate infestation level (5,000 eggs per plant). Under all infestation levels tested in this work, gall and egg mass indexes (MI) did not differ from the untreated controls, bringing concerns related to the practical adoption of this control strategy by farmers. In our opinion, if the fungi P . chlamydosporia and P . lilacinum are to be used as biocontrol tools toward M. entorolobii , they should focus on

Atividade dissacaridásica intestinal da esquistossomose mansônica: estudo evolutivo em camundongos com diferentes cargas de infestação

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M. G. A. Sadek

1986-04-01

Full Text Available A esquistossomose mansônica compromete vários órgãos, sendo o intestino e o fígado os mais agredidos. Com a intenção de verificar o comprometimento do intestino delgado, dependente da intensidade e do tempo de infecção pelo Schistosoma mansoni, analisou-se a atividade das dissacaridases — lactase, sacarase e maltase — em 112 camundongos, distribuídos em 3 grupos: grupo I — controle, grupo II — infestado com 30 cercárias, grupo III — infestado com 60 cercárias. Observamos uma diminuição da atividade lactásica, sacarásica e maltásica do intestino delgado, decorrente da infestação esquistossomdtica, do tempo de infestação e da alteração entre ambos. O íleo é o segmento que demonstrou maior sensibilidade a esquistossomose, tendo uma diminuição das suas dissacaridases a partir da fase inicial de infestação. Opostamente, o jejuno só mais tardiamente mostra essas alterações, exceto em relação a lactase. Detectou-se um aumento da atividade dissacaridásica, inclusive para a lactase, em todos os grupos, com a evolução etária dos animais, quantitativamente menor nos infestados. Cargas de 30 e 60 cercárias devem ser consideradas de mesmo porte, pois produziram ledução semelhante na atividade dissacaridásica.

Dasypus novemcinctus infestado con schizotrypanum cruzi en condiciones naturales

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Augusto Corredor Arjona

1963-04-01

Full Text Available The present publication is the first of a series on Chagas disease in the region of Pizarreal, Municipality of Patios, department of North Santander, Colombia. The authors describe the second case in Colombia of Dasypus nouemcinctus infected in natural form by Schizotrypanum cruzi.

The combined use of Pochonia chlamydosporia and plant defence activators - a potential sustainable control strategy for Meloidogyne chitwoodi

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Maria Clara VIEIRA DOS SANTOS

2014-05-01

Full Text Available Sustainable strategies are required for control of the root-knot nematode Meloidogyne chitwoodi to reduce dependence on toxic chemical pesticides. The efficacy of the nematophagous fungus Pochonia chlamydosporia in biocontrol could be enhanced by integration with control measures that reduce initial nematode infestations. The use of foliar sprays with plant defence activators can reduce the susceptibility of potato plants to M. chitwoodi. This study assessed effects of combined soil application of P. chlamydosporia with foliar sprays of benzothiadiazole (BTH or cis-jasmone on infection of potatoes by M. chitwoodi. Solanum tuberosum, cv. Désirée plants were grown in soil mixed with 5000 chlamydospores g-1 of soil, sprayed twice with BTH or cis-jasmone and inoculated with 300 M. chitwoodi second-stage juveniles. Forty-five days after inoculation, nematode reproduction, numbers of colony-forming units of the fungus g-1 of soil and g-1 of root, and egg parasitism were assessed by standard techniques. Foliar sprays of BTH or cis-jasmone combined with the fungus reduced nematode reproduction (P<0.05, LSD. The presence of the fungus slightly increased the efficacy of cis-jasmone, as the number of eggs per egg mass was less in plants treated both with cis-jasmone and the fungus than in the plants treated only with the defence activator. The proportion of parasitized eggs was greater in the cis-jasmone treatment where rhizosphere colonisation was less, suggesting that P. chlamydosporia became a poorer rhizosphere coloniser but a more efficient nematode parasite. The addition of P. chlamydosporia to soil in combination with application of inducers of plant defence could be an alternative control strategy to be used against M. chitwoodi in potato.

Optimizing the efficacy of Paecilomyces lilacinus (strain 251) for the control of root-knot nematodes.

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Kiewnick, S; Sikora, R A

2004-01-01

The egg pathogenic fungus Paecilomyces lilacinus (strain 251) is a biocontrol fungus with a potential range of activity to control the worldwide most important plant parasitic nematodes. This biological nematicide may be an useful tool in an integrated approach to control mainly sedentary nematodes. Greenhouse experiments were conducted with the root-knot nematodes Meloidogyne incognita and M. hapla on tomato. P. lilacinus, formulated as WG (BIOACT WG), was incorporated into soil inoculated with root-knot nematode eggs prior to transplanting the susceptible tomato cultivar "Hellfrucht". Furthermore, soil treatments were combined with seedling treatments 24 hours before transplanting and a soil drench 2 weeks after planting, respectively. Seedling and post planting treatment was also combined with a soil treatment at planting. All single or combination treatments tested decreased the gall index and the number of egg masses compared to the untreated control 12 weeks after planting. However, the combination of the seedling treatment with a pre- or at-planting application of P. lilacinus was necessary to achieve higher levels of control. Additional post plant drenching resulted in only a slight increase In efficacy. To the feasibility of this modified application system for the control of root-knot nematodes, a yield experiment was conducted with M. hapla and the susceptible cultivar "Gnom F1 Hybrid". It could be demonstrated that the above mentioned combination of pre-planting application plus the seedling and one post plant drench gave the best control and resulted in a significant fruit yield increase in concurrence with a decrease in number of galls per root.

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

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Atul Kakrana

2017-12-01

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

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

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

2018-02-27

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

Turbulent Flow and Large Surface Wave Events in the Marine Boundary Layers

Science.gov (United States)

2013-08-22

Nether-784 lands Academy of Arts and Sciences.785 35 Wyngaard, J. C., 2004: Toward numerical modeling in the Terra Incognita. J. Atmos. Sci.,786 61...surface roughness, vegetative canopies, wind waves and local orography all influence wind turbine performance to varying degrees. For exam- ple, the...teor crater, Bull. Amer. Meteorol. Soc., 89, 127–150. Wyngaard, J. C., 2004: Toward numerical modeling in the Terra Incognita, J. Atmos. Sci., 61

REAÇÃO DA PINHA (Annona squamosa L. A TRÊS ESPÉCIES DE FITONEMATÓIDES

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A.R. Monteiro

1996-05-01

Full Text Available Em ensaio conduzido em vasos, a céu aberto, estudou-se a reação de Annona squamosa em relação a três nematóides fitoparasitos. As plantas foram inoculadas com 10.000 exemplares de Radopholus similis, Rotylenchulus reniformis ou Meloidogyne exigua por recipiente. Avaliaram-se, após três meses da inoculação, a altura das plantas, o peso fresco do sistema radicular e o número de nematóides nas raízes e no solo. O estudo revelou que a Annona squamosa comportou-se como resistente a Rotylenchulus reniformis e a Meloidogyne exigua, e intolerante a Radopholus similis.The host reaction of custard apple (Annona squamosa to three species of nematodes was studied. The plants were inoculated with 10,000 specimens per plant of Radopholus similis, Rotylenchulus reniformis or Meloidogyne exigua. Nematode population and plant growth parameters were evaluated three months later. The results showed that custard apple was resistent to Rotylenchulus reniformis and Meloidogyne exigua but intolerant to Radopholus similis.

Transcriptional profiling of root-knot nematode induced feeding sites in cowpea (Vigna unguiculata L. Walp. using a soybean genome array

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Das Sayan

2010-08-01

Full Text Available Abstract Background The locus Rk confers resistance against several species of root-knot nematodes (Meloidogyne spp., RKN in cowpea (Vigna unguiculata. Based on histological and reactive oxygen species (ROS profiles, Rk confers a delayed but strong resistance mechanism without a hypersensitive reaction-mediated cell death process, which allows nematode development but blocks reproduction. Results Responses to M. incognita infection in roots of resistant genotype CB46 and a susceptible near-isogenic line (null-Rk were investigated using a soybean Affymetrix GeneChip expression array at 3 and 9 days post-inoculation (dpi. At 9 dpi 552 genes were differentially expressed in incompatible interactions (infected resistant tissue compared with non-infected resistant tissue and 1,060 genes were differentially expressed in compatible interactions (infected susceptible tissue compared with non-infected susceptible tissue. At 3 dpi the differentially expressed genes were 746 for the incompatible and 623 for the compatible interactions. When expression between infected resistant and susceptible genotypes was compared, 638 and 197 genes were differentially expressed at 9 and 3 dpi, respectively. Conclusions In comparing the differentially expressed genes in response to nematode infection, a greater number and proportion of genes were down-regulated in the resistant than in the susceptible genotype, whereas more genes were up-regulated in the susceptible than in the resistant genotype. Gene ontology based functional categorization revealed that the typical defense response was partially suppressed in resistant roots, even at 9 dpi, allowing nematode juvenile development. Differences in ROS concentrations, induction of toxins and other defense related genes seem to play a role in this unique resistance mechanism.

Genetics of simple and complex host-parasite interactions

International Nuclear Information System (INIS)

Sidhu, G.S.; Webster, J.M.

1977-01-01

In nature a host plant can be viewed as a miniature replica of an ecological system where true and incidental parasites share the same habitat. Consequently, they influence each other's presence directly by interspecific interaction, and indirectly by inducing changes in the host's physiology and so form disease complexes. Since all physiological phenomena have their counterpart in the respective genetic systems of interacting organisms, valuable genetic information can be derived from the analysis of complex parasitic systems. Disease complexes may be classified according to the nature of interaction between various parasites on the same host. One parasite may nullify the host's resistance to another (e.g. Tomato - Meloidogyne incognita + Fusarium oxysporum lycopersici system). Conversely, a parasite may invoke resistance in the host against another parasite (e.g. Tomato - Fusarium oxysporum lycopersici + Verticillium albo atrum system). From the study of simple parasitic systems we know that resistance versus susceptibility against a single parasite is normally monogenically controlled. However, when more than one parasite interacts to invoke or nullify each other's responses on the same host plant, the genetic results suggest epistatic ratios. Nevertheless, epistatic ratios have been obtained also from simple parasitic systems owing to gene interaction. The epistatic ratios obtained from complex and simple parasitic systems are contrasted and compared. It is suggested that epistatic ratios obtained from simple parasitic systems may, in fact, be artifacts resulting from complex parasitic associations that often occur in nature. Polygenic inheritance and the longevity of a cultivar is also discussed briefly in relation to complex parasitic associations. Induced mutations can play a significant role in the study of complex parasitic associations, and thus can be very useful in controlling plant diseases

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

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

2015-01-01

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

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

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Yu Li

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

Estudio de la fertilidad y viabilidad de quistes hidatídicos ovinos

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García Llamazares José Luis

1997-01-01

Full Text Available FUNDAMENTO: La finalidad de este trabajo es analizar la fertilidad de los quistes hidatídicos de origen ovino, especie de gran interés epidemiológico en la hidatidosis, y la adecuación del gerbillo (Meriones unguiculatus como modelo experimental para el estudio "in vivo" de dicha hidatidosis, fase preliminar de posteriores estudios terapeúticos. MÉTODOS: Se ha realizado un estudio de la fertilidad y viabilidad de quistes hidatídicos procedentes de pulmones e hígados de ganado ovino de Castilla y León a través del examen y evaluación de una serie de parámetros entre los que figura la producción de una hidatidosis secundaria experimental en animales de laboratorio. RESULTADOS: El índice quístico total obtenido fue de 8,57 quistes por ovino infestado (5,97 quistes por pulmón infestado y 5,57 quistes por hígado infestado. El porcentaje de fertilidad obtenido en los quistes hidatídicos de origen ovino que contenían protoescólex viables "in vitro" fue del 43,97% (43,02% en los quistes pulmonares y 46,16% en los quistes hepáticos. La viabilidad "in vivo" de los protoescólex seleccionados se puso de manifiesto al producirse en el 100% de los gerbillos infectados una hidatidosis secundaria experimental. CONCLUSIONES: Se destaca la validez de los criterios utilizados para estudiar la viabilidad "in vitro" de los protoescólex procedentes de quistes hidatídicos de origen ovino. La hidatidosis secundaria producida en gerbillos nos conduce a considerarlos como especie de experimentación adecuada para la investigación "in vivo" de la hidatidosis de origen ovino.

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

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Alvarez César G.

1998-12-01

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

Soil amendment with chopped or ground dry leaves of six species of plants for the control of Meloidogyne javanica in tomato under greenhouse conditions Incorporação ao solo de folhas secas picadas ou moídas de seis espécies de plantas para o controle de Meloidogyne javanica em tomateiro em casa de vegetação

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Everaldo Antônio Lopes

2011-06-01

Full Text Available Greenhouse experiments were conducted to evaluate the effect of soil amendment with chopped (1cm² or ground (1mm sieve dry leaves of assa-peixe (Vernonia polyanthes, lemon-grass (Cymbopogon citratus, eucalyptus (Eucalyptus citriodora, castor (Ricinus communis, mango (Mangifera indica or neem (Azadirachta indica for the control Meloidogyne javanica. Into the soil (Yellow red oxisol of each pot were added leaves (5g kg-1 of soil and 5,000 eggs of the nematode. After seven days, one tomato seedling "Santa Cruz Kada" was transplanted to each pot. The tomato root weight, galls and eggs/root system were determined 60 days after transplant. None of the soil amendments reduced gall or eggs, when applied as leaf pieces. However, all tested plant species reduced the gall number, when they were incorporated into the soil as powder, and maximum nematode suppression occurred in soil amended with neem leaves (61%. The amendment with ground leaves of castor, neem, eucalyptus and lemon-grass reduced the number of eggs, with maximum reduction occurring in soil amended with ground castor leaves (69%, evidencing that these organic amendments can be an alternative for M. javanica control in tomato. Further studies are required under field conditions to confirm the potential of these organic amendments on the control of M. javanica.Experimentos em casa de vegetação foram conduzidos com o objetivo de avaliar o efeito da adição ao solo de folhas secas picadas (1cm² ou trituradas (peneira de 1mm de assa-peixe (Vernonia polyanthes, capim-limão (Cymbopogon citratus, eucalipto (Eucalyptus citriodora, mamona (Ricinus communis, manga (Mangifera indica ou nim (Azadirachta indica para o controle de Meloidogyne javanica. Ao solo de cada vaso (latossolo vermelho-amarelo, foram adicionadas folhas (5g kg-1 de solo e 5.000 ovos do nematoide. Após sete dias, uma muda de tomateiro "Santa Cruz Kada" foi transplantada em cada vaso. O peso das raízes e os números de galhas e

Efecto de diferentes densidades poblacionales de Meloidogyne hapla sobre uchuva (Physalis peruviana L. en invernadero

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Niño Nancy Eunice

2008-04-01

Full Text Available

Este estudio se realizó en el Centro de Investigaciones y Asesorías Agroindustriales de la Universidad de Bogotá Jorge Tadeo Lozano, Chía (Cundinamarca, bajo condiciones de invernadero, durante diez meses de cultivo. Se evaluó el efecto de diferentes densidades poblacionales de Meloidogyne hapla (0, 50, 100, 200, 500 y 1.000 larvas J2/100 cc de suelo, sobre parámetros productivos de la uchuva: altura de las plantas, diámetro de tallo, peso fresco, peso seco y biomasa de follaje, peso fresco de raíces, índice de nodulación radicular y peso fresco de frutos. Se hizo análisis de varianza, pruebas de contrastes y prueba de Tukey (α=0,05, en un diseño completamente aleatorio, con seis tratamientos y cinco repeticiones, mediante el programa SAS v.8.0. El tratamiento de 500 larvas J2/100 cc suelo fue el que más afectó la altura de las plantas, el diámetro del tallo, la biomasa de follaje, el peso fresco de raíces y presentó el índice de nodulación radical más alto. No se encontraron diferencias significativas entre los tratamientos inoculados con M. hapla , para peso fresco, peso seco de follaje y peso fresco de frutos, ni para el número de larvas J2 en suelo y masas de huevos. Mediante la ecuación: Y = m + (1–mZ^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.

Controle de Meloidogyne javanica em mudas de bananeira 'prata-anã' por compostos orgânicos

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Bruna Hanielle Carneiro dos Santos

2013-06-01

Full Text Available O trabalho teve como objetivo avaliar o efeito de compostos orgânicos no controle de Meloidogyne javanica, e no desenvolvimento de mudas de bananeiras 'Prata-Anã. O experimento foi conduzido em DIC, com dez repetições, e os tratamentos consistiram em quatro compostos constituídos de diferentes matérias-primas (restos da cultura da banana, cana-de-açúcar, esterco bovino, cascas de banana, plantas daninhas, capim andropogon, o esterco bovino, a torta de mamona e testemunhas (adubação mineral, carbofuran e testemunha absoluta (sem adição de composto orgânico. Em cada vaso, foram colocados 3 kg de solo autoclavado, incorporado com cada um dos tratamentos avaliados e inoculado com suspensão contendo 4.000 ovos de M. javanica. Após quatro dias, transplantou-se uma muda de bananeira 'Prata-Anã' micropropagada, e aos 60 dias, avaliaram-se: altura das plantas, diâmetro, número de folhas e peso de matéria seca da parte aérea, e número de galhas, massas de ovos, número de ovos e o número de juvenis de segundo estádio (J2, por 100 cm³ de solo. Testou-se in vitro o efeito das frações húmicas dos quatro compostos (que não causaram fitotoxidez e esterco bovino sobre a mortalidade e motilidade de J2 de M. javanica. O ensaio foi montado em placas de ELISA em DIC, com cinco repetições. Os compostos orgânicos e o esterco bovino aumentaram o desenvolvimento das mudas. A torta de mamona provocou efeito fitotóxico às mudas. Menor número de variáveis nematológicas foi proporcionado pela torta de mamona e pelo carbofuran. O número de J2 também foi menor nas parcelas tratadas com carbofuran e também pelo Composto 3, constituído por plantas daninhas+restos de cana-de-açúcar+ esterco bovino e pelo adubo mineral. Para o teste in vitro, as substâncias húmicas conferiram efeito nematicida e nematostático. Dentre os compostos, o C3 mostrou-se promissor por reduzir o desenvolvimento do nematoides e não apresentar efeito fitotóxico.

Parasitismo intestinal en una escuela primaria de Bata, Guinea Ecuatorial Intestinal parasitism in an elementary school in Bata, Equatorial Guinea

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William Quintero Pérez

2008-06-01

Full Text Available Con el objetivo de precisar el grado de parasitismo intestinal según la edad, así como identificar los parásitos intestinales más frecuentes en la escuela primaria "Amiguitos de Jesús" de la ciudad de Bata, Guinea Ecuatorial, en el periodo septiembre 2002 a Junio 2003, se realizó un estudio descriptivo y prospectivo. En el mismo se encontró que el grado de parasitismo intestinal fue de un 29.9 % del total de análisis realizados, predominando sobre todo en los menores de 6 años; un 44.7% de éstos estaban infestados. Se encontró un predominio de los vermes: el más frecuente fue Trichuris trichiura, para el 95.1 % del total de niños infestados, y el áscaris lumbricoides, con un 75.6% del total de 41 infestados. De los protozoos, el más frecuente fue la ameba, existiendo en un 17.07 % de los infestados. El grado de infestación encontrado es elevado, requiriéndose programas educativos para fomentar el cuidado de los hábitos higiénicos de los niños. El predominio de los parásitos encontrados podría deberse a la contaminación de la tierra con heces fecales y a la falta de un adecuado tratamiento de las aguas para el consumo, y de infraestructura sanitaria.With the aim of defining exactly the grade of intestinal parasitism according to age, as well as identifying the most frequent intestinal parasites in "Amiguitos de Jesús" Elementary School in Bata City, Equatorial Guinea, during septembre 2002 to June 2003, a descriptive, prospective study is carried out. In the study it was found that the parasitism grade was 29.9% from the total of the analysis performed, predominating in those under 6 years of age: 44.7% of these cases were infected. A prevalence of vermes was observed, Trichuris trichiuria was the most frequent species found, representing 95,1% from the total of infected children and Ascaris lumbricoides 75,6% from the total of 41 infected. Among protozoa, amoeba was the most frequent specie observed, being present in 17

Effects of temperature on the life-history traits of Sancassania (Caloglyphus) berlesei (Acari: Astigmatina: Acaridae) feeding on root-knot nematodes, Meloidogyne spp. (Nematoda: Meloidogynidae).

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Abou El-Atta, Doaa Abd El-Maksoud; Ghazy, Noureldin Abuelfadl; Osman, Mohamed Ali

2014-11-01

Sancassania (Caloglyphus) berlesei (Michael) is a cosmopolitan and free-living mite that inhabits soil as well as laboratory colonies of insects and fungi and may have a role as a biocontrol agent of nematodes. In this study, we investigated the effects of temperature on the development, reproduction, and food consumption of S. berlesei fed egg masses of root-knot nematodes, Meloidogyne spp., an important group of agricultural pests. Mites were reared at 20, 25 or 30 °C in the dark. The mites could feed on the nematode egg masses, and their developmental time decreased at higher temperatures. Time from the egg to adult was similar in females and males reared at the same temperature. Adult females lived longer than males at 25 °C, but not at 20 or 30 °C. Generally, females showed a higher rate of food consumption than males. Females laid the largest number of eggs at 20 and 25 °C (199.7 and 189.8 eggs/female, respectively), but the intrinsic rate of natural increase was highest at 30 °C (r m = 0.29). In comparing our data with previous reports, we noted that S. berlesei that fed on egg masses of root-knot nematodes showed a longer developmental time and a lower reproductive rate than Sancassania mites that fed on other diets. Nonetheless, the relatively high value of r m (e.g., at 25 and 30 °C) suggests that this mite may have certain advantages as a biocontrol agent of root-knot nematodes.

A novel Meloidogyne graminicola effector, MgGPP, is secreted into host cells and undergoes glycosylation in concert with proteolysis to suppress plant defenses and promote parasitism.

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Jiansong Chen

2017-04-01

Full Text Available Plant pathogen effectors can recruit the host post-translational machinery to mediate their post-translational modification (PTM and regulate their activity to facilitate parasitism, but few studies have focused on this phenomenon in the field of plant-parasitic nematodes. In this study, we show that the plant-parasitic nematode Meloidogyne graminicola has evolved a novel effector, MgGPP, that is exclusively expressed within the nematode subventral esophageal gland cells and up-regulated in the early parasitic stage of M. graminicola. The effector MgGPP plays a role in nematode parasitism. Transgenic rice lines expressing MgGPP become significantly more susceptible to M. graminicola infection than wild-type control plants, and conversely, in planta, the silencing of MgGPP through RNAi technology substantially increases the resistance of rice to M. graminicola. Significantly, we show that MgGPP is secreted into host plants and targeted to the ER, where the N-glycosylation and C-terminal proteolysis of MgGPP occur. C-terminal proteolysis promotes MgGPP to leave the ER, after which it is transported to the nucleus. In addition, N-glycosylation of MgGPP is required for suppressing the host response. The research data provide an intriguing example of in planta glycosylation in concert with proteolysis of a pathogen effector, which depict a novel mechanism by which parasitic nematodes could subjugate plant immunity and promote parasitism and may present a promising target for developing new strategies against nematode infections.

Evaluación in vitro de hongos nematófagos en zonas arroceras de Costa Rica contra el nematodo agallador Meloidogyne javanica

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Walter Peraza Padilla

2014-12-01

Full Text Available Se evaluó el parasitismo in vitro de 14 aislamientos de hongos nematófagos (6 Trichoderma sp., 4 Paecilomyces sp., 2 Fusarium oxysporum, y 2 Monacrosporium sp. contra juveniles y huevos del nematodo agallador Meloidogyne javanica. Los hongos, de 3 regiones productoras de arroz en Costa Rica, (Pacífico Central, Huetar Atlántica y Chorotega, se aislaron mediante el método de espolvoreado en placas, durante abril del 2008 a agosto de 2009. Se utilizó un diseño completamente al azar con 10 repeticiones por hongo, en agar-agua (AA. Se inoculó una suspensión de 1 a 1,5x10 6 conidios (ufc.ml -1 por plato Petri, y al cuarto día se depositó en 0,5 ml una suspensión de 150 juveniles y 100 huevos de M. javanica previamente desinfectados, a temperatura ambiente (23-26°C y con luz natural. Transcurridas 96 h se contó en cada plato el número de nematodos vivos, muertos ó parasi- tados y de huevos parasitados o no parasitados. Se realizó un análisis de regresión logística (RL para las variables evaluadas, el cual mostró diferencias significativas (p<0,0001 en el desempeño de los hongos evaluados, presentando rangos de entre 10% a 56% en nematodos muertos, de 13% a 79% en nematodos parasitados y de 1% a 96% en huevos parasitados. En general, los hongos del género Trichoderma (Tri1, Tri2, Tri3 y Tri4 fueron los más eficientes en el parasitismo sobre juveniles y huevos de M. javanica.

Non-pathogenic Fusarium solani represses the biosynthesis of nematicidal compounds in vitro and reduces the biocontrol of Meloidogyne javanica by Pseudomonas fluorescens in tomato.

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Siddiqui, I A; Shaukat, S S

2003-01-01

The aim of the present investigation was to determine the influence of various Fusarium solani strains on the production of nematicidal agent(s) in vitro and biocontrol of Meloidogyne javanica in tomato by Pseudomonas fluorescens strains CHA0 and CHA0/pME3424. Culture filtrates (CF) of P. fluorescens strain CHA0 and its diacetylphloroglucinol-overproducing derivative CHA0/pME3424 caused substantial mortality of M. javanica juveniles in vitro. Bacterial growth medium amended with the growth medium of F. solani repressed the nematicidal activity of the bacteria. Methanol extract of F. solani CF resulting from Czapek's Dox liquid (CDL) medium without zinc amendment repressed the nematicidal activity of the bacteria while the CF obtained from CDL medium amended with zinc did not. Conidial suspension of F. solani strain Fs5 (repressor strain for the biosynthesis of nematicidal compounds in P. fluorescens) reduced biocontrol potential of the bacterial inoculants against M. javanica in tomato while strain Fs3 (non-repressor) did not. Fusarium solani strains with increased nematicidal activity repress the biosynthesis of nematicidal compounds by P. fluorescens strains in vitro and greatly alter its biocontrol efficacy against root-knot nematode under natural conditions. Fusarium solani strains are distributed worldwide and found in almost all the agricultural fields which suggest that some mycotoxin-producing strains will also be found in almost any soil sample taken. Besides the suppressive effect of these metabolite-producing strains on the production of nematicidal compound(s) critical in biocontrol, F. solani strains may also affect the performance of mycotoxin-sensitive biocontrol bacteria effective against plant-parasitic nematodes.

Y WHITE CHITWOOD

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Raquel Cervantes-Moreno

2014-01-01

Full Text Available Se determinó la tolerancia de 26 colectas de tomates nativos de México a Meloidogyne incongnita (Kofoid y White Chit- wood, con el fin de identificar aquellas con potencial para su empleo en el mejoramiento genético o como portainjertos. Para ello, plantas de 30 días de edad fueron establecidas en hidroponia bajo invernadero. Diez días después del trasplante (ddt fue aplicada al sustrato una solución con 100,000 huevecillos-larva por planta. Se registraron caracteres de la parte aérea de plantas y a los 210 ddt se cuantificó el desarrollo de poblaciones de nematodos en raíces. M. incognita disminuyó el diámetro de frutos y el porte de planta (altura al primer racimo, peso seco de tallo y número de nudos, e incrementó el número de frutos y flores. Además, redujo la longitud de raíces y aumentó el volumen de éstas por la formación de nó- dulos. Mediante análisis multivariados (agrupamiento y discriminante se definieron cinco grupos de colectas en función de la cantidad de agallas pequeñas y grandes, así como el total de éstas (82 % de variación y por la cantidad de larvas en raíz y huevecillos en sustrato (13 % de variación. Se identificaron tres colectas tolerantes con bajos índices de agallas y menor presencia de huevecillos-larva en raíz y en sustrato. Ocho colectas fueron moderadamente tolerantes; nueve, moderadamente susceptibles, y seis, susceptibles. No se detectaron asociaciones entre orígenes de colectas o forma de fruto con respecto a la tolerancia al nematodo.

Apoplastic Venom Allergen-like Proteins of Cyst Nematodes Modulate the Activation of Basal Plant Innate Immunity by Cell Surface Receptors

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Lozano-Torres, Jose L.; Wilbers, Ruud H. P.; Warmerdam, Sonja; Finkers-Tomczak, Anna; Diaz-Granados, Amalia; van Schaik, Casper C.; Helder, Johannes; Bakker, Jaap; Goverse, Aska; Schots, Arjen; Smant, Geert

2014-01-01

Despite causing considerable damage to host tissue during the onset of parasitism, nematodes establish remarkably persistent infections in both animals and plants. It is thought that an elaborate repertoire of effector proteins in nematode secretions suppresses damage-triggered immune responses of the host. However, the nature and mode of action of most immunomodulatory compounds in nematode secretions are not well understood. Here, we show that venom allergen-like proteins of plant-parasitic nematodes selectively suppress host immunity mediated by surface-localized immune receptors. Venom allergen-like proteins are uniquely conserved in secretions of all animal- and plant-parasitic nematodes studied to date, but their role during the onset of parasitism has thus far remained elusive. Knocking-down the expression of the venom allergen-like protein Gr-VAP1 severely hampered the infectivity of the potato cyst nematode Globodera rostochiensis. By contrast, heterologous expression of Gr-VAP1 and two other venom allergen-like proteins from the beet cyst nematode Heterodera schachtii in plants resulted in the loss of basal immunity to multiple unrelated pathogens. The modulation of basal immunity by ectopic venom allergen-like proteins in Arabidopsis thaliana involved extracellular protease-based host defenses and non-photochemical quenching in chloroplasts. Non-photochemical quenching regulates the initiation of the defense-related programmed cell death, the onset of which was commonly suppressed by venom allergen-like proteins from G. rostochiensis, H. schachtii, and the root-knot nematode Meloidogyne incognita. Surprisingly, these venom allergen-like proteins only affected the programmed cell death mediated by surface-localized immune receptors. Furthermore, the delivery of venom allergen-like proteins into host tissue coincides with the enzymatic breakdown of plant cell walls by migratory nematodes. We, therefore, conclude that parasitic nematodes most likely utilize

Apoplastic venom allergen-like proteins of cyst nematodes modulate the activation of basal plant innate immunity by cell surface receptors.

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Lozano-Torres, Jose L; Wilbers, Ruud H P; Warmerdam, Sonja; Finkers-Tomczak, Anna; Diaz-Granados, Amalia; van Schaik, Casper C; Helder, Johannes; Bakker, Jaap; Goverse, Aska; Schots, Arjen; Smant, Geert

2014-12-01

Despite causing considerable damage to host tissue during the onset of parasitism, nematodes establish remarkably persistent infections in both animals and plants. It is thought that an elaborate repertoire of effector proteins in nematode secretions suppresses damage-triggered immune responses of the host. However, the nature and mode of action of most immunomodulatory compounds in nematode secretions are not well understood. Here, we show that venom allergen-like proteins of plant-parasitic nematodes selectively suppress host immunity mediated by surface-localized immune receptors. Venom allergen-like proteins are uniquely conserved in secretions of all animal- and plant-parasitic nematodes studied to date, but their role during the onset of parasitism has thus far remained elusive. Knocking-down the expression of the venom allergen-like protein Gr-VAP1 severely hampered the infectivity of the potato cyst nematode Globodera rostochiensis. By contrast, heterologous expression of Gr-VAP1 and two other venom allergen-like proteins from the beet cyst nematode Heterodera schachtii in plants resulted in the loss of basal immunity to multiple unrelated pathogens. The modulation of basal immunity by ectopic venom allergen-like proteins in Arabidopsis thaliana involved extracellular protease-based host defenses and non-photochemical quenching in chloroplasts. Non-photochemical quenching regulates the initiation of the defense-related programmed cell death, the onset of which was commonly suppressed by venom allergen-like proteins from G. rostochiensis, H. schachtii, and the root-knot nematode Meloidogyne incognita. Surprisingly, these venom allergen-like proteins only affected the programmed cell death mediated by surface-localized immune receptors. Furthermore, the delivery of venom allergen-like proteins into host tissue coincides with the enzymatic breakdown of plant cell walls by migratory nematodes. We, therefore, conclude that parasitic nematodes most likely utilize

Apoplastic venom allergen-like proteins of cyst nematodes modulate the activation of basal plant innate immunity by cell surface receptors.

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Jose L Lozano-Torres

2014-12-01

Full Text Available Despite causing considerable damage to host tissue during the onset of parasitism, nematodes establish remarkably persistent infections in both animals and plants. It is thought that an elaborate repertoire of effector proteins in nematode secretions suppresses damage-triggered immune responses of the host. However, the nature and mode of action of most immunomodulatory compounds in nematode secretions are not well understood. Here, we show that venom allergen-like proteins of plant-parasitic nematodes selectively suppress host immunity mediated by surface-localized immune receptors. Venom allergen-like proteins are uniquely conserved in secretions of all animal- and plant-parasitic nematodes studied to date, but their role during the onset of parasitism has thus far remained elusive. Knocking-down the expression of the venom allergen-like protein Gr-VAP1 severely hampered the infectivity of the potato cyst nematode Globodera rostochiensis. By contrast, heterologous expression of Gr-VAP1 and two other venom allergen-like proteins from the beet cyst nematode Heterodera schachtii in plants resulted in the loss of basal immunity to multiple unrelated pathogens. The modulation of basal immunity by ectopic venom allergen-like proteins in Arabidopsis thaliana involved extracellular protease-based host defenses and non-photochemical quenching in chloroplasts. Non-photochemical quenching regulates the initiation of the defense-related programmed cell death, the onset of which was commonly suppressed by venom allergen-like proteins from G. rostochiensis, H. schachtii, and the root-knot nematode Meloidogyne incognita. Surprisingly, these venom allergen-like proteins only affected the programmed cell death mediated by surface-localized immune receptors. Furthermore, the delivery of venom allergen-like proteins into host tissue coincides with the enzymatic breakdown of plant cell walls by migratory nematodes. We, therefore, conclude that parasitic nematodes

In vitro antagonistic activity, plant growth promoting traits and phylogenetic affiliation of rhizobacteria associated with wild plants grown in arid soil.

Science.gov (United States)

El-Sayed, Wael S; Akhkha, Abdellah; El-Naggar, Moustafa Y; Elbadry, Medhat

2014-01-01

The role of plant growth-promoting rhizobacteria (PGPR) in adaptation of plants in extreme environments is not yet completely understood. For this study native bacteria were isolated from rhizospeheric arid soils and evaluated for both growth-promoting abilities and antagonistic potential against phytopathogenic fungi and nematodes. The phylogentic affiliation of these representative isolates was also characterized. Rhizobacteria associated with 11 wild plant species from the arid soil of Almadinah Almunawarah, Kingdom of Saudi Arabia (KSA) were investigated. From a total of 531 isolates, only 66 bacterial isolates were selected based on their ability to inhibit Fusarium oxysporum, and Sclerotinia sclerotiorum. The selected isolates were screened in vitro for activities related to plant nutrition and plant growth regulation as well as for antifungal and nematicidal traits. Isolated bacteria were found to exhibit capabilities in fix atmospheric nitrogen, produce ammonia, indoleacetic acid (IAA), siderophores, solubilize phosphate and zinc, and showed an antagonistic potential against some phytopathogenic fungi and one nematode species (Meloidogyne incognita) to various extent. Isolates were ranked by their potential ability to function as PGPR. The 66 isolates were genotyped using amplified rDNA restriction analysis (ARDRA) and 16S rRNA gene sequence analysis. The taxonomic composition of the representative genotypes from both rhizosphere and rhizoplane comprised Bacillus, Enterobacter and Pseudomonas. Out of the 10 genotypes, three strains designated as PHP03, CCP05, and TAP02 might be regarded as novel strains based on their low similarity percentages and high bootstrap values. The present study clearly identified specific traits in the isolated rhizobacteria, which make them good candidates as PGPR and might contribute to plant adaption to arid environments. Application of such results in agricultural fields may improve and enhance plant growth in arid soils.

In vitro Antagonistic Activity, Plant Growth Promoting Traits and Phylogenetic Affiliation of Rhizobacteria Associated with Wild Plants Grown in Arid Soil

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Wael Samir El-Sayed

2014-12-01

Full Text Available The role of plant growth-promoting rhizobacteria (PGPR in adaptation of plants in extreme environments is not yet completely understood. For this study native bacteria were isolated from rhizospeheric arid soils and evaluated for both growth-promoting abilities and antagonistic potential against phytopathogenic fungi and nematodes. The phylogentic affiliation of these representative isolates was also characterized. Rhizobacteria associated with eleven wild plant species from the arid soil of Almadinah Almunawarah, Kingdom of Saudi Arabia (KSA were investigated. From a total of 531 isolates, only 66 bacterial isolates were selected based on their ability to inhibit Fusarium oxysporum, and Sclerotinia sclerotiorum. The selected isolates were screened in vitro for activities related to plant nutrition and plant growth regulation as well as for antifungal and nematicidal traits. Isolated bacteria were found to exhibit capabilities in fix atmospheric nitrogen, produce ammonia, indoleacetic acid (IAA, siderophores, solubilize phosphate and zinc, and showed an antagonistic potential against some phytopathogenic fungi and one nematode species (Meloidogyne incognita to various extent. Isolates were ranked by their potential ability to function as PGPR. The 66 isolates were genotyped using amplified rDNA restriction analysis (ARDRA and 16S rRNA gene sequence analysis. The taxonomic composition of the representative genotypes from both rhizosphere and rhizoplane comprised Bacillus, Enterobacter and Pseudomonas. Out of the ten genotypes, three strains designated as PHP03, CCP05, and TAP02 might be regarded as novel strains based on their low similarity percentages and high bootstrap values. The present study clearly identified specific traits in the isolated rhizobacteria, which make them good candidates as PGPR and might contribute to plant adaption to arid environments. Application of such results in agricultural fields may improve and enhance plant

Karakterisasi dan uji aktivitas Bacillus spp. sebagai agensia pengendalian hayati penyakit lincat pada tembakau Temanggung

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Triwidodo Arwiyanto

2012-02-01

Full Text Available Lincat disease of tobacco causing severe losses of the product. Control of the disease with any available measure unlikely giving enough control. A number of Bacillus spp. isolates could suppressed the growth of pathogen in vitro and suppressed the development of lincat disease in the field. This article report the charactheristics of six isolates of Bacillus spp. (Ba-4, Ba-22, Ba-24, Ba-30, Ba-33, dan Ba-41. These isolates proven could suppressed lincat disease in the field. Characterization of the isolates include the morphological, physiological characteristics, and pathogenicity against tobacco plant. The results indicated that the bacterial isolates were belong to the genus Bacillus with the following charactheristics. The bacteria were rod shapes, forming endospore, Gram positive, fermentative, positive reaction in katalase, oksidase, and Voges Proskaeur tests. Negative results were obtained for Methyl Red test, hydrolysis of starch, gelatine, and casein. The present isolates could use citrate and several carbohydrates as carbon sources. Reduce nitrate to nitrite. The isolates could grow in the medium with high osmotic pressure, i.e. could grow in the medium with 7% NaCl. The present isolates grew well in the medium with pH of 4.5 €“10 and could grow in the temperature range of 10 €“50 °C. According to pathogenicity test, the present isolates were not belong to the plant pathogenic bacteria. The present isolates could suppressed the growth of Ralstonia solanacearum in vitro, and could reduce the egg number of Meloidogyne incognita. According to the physiological charactheristics tested, it seem that isolates of Ba-4, Ba-24, Ba-30, dan Ba-33, and Ba-41 having similar charactheristics with Bacillus cereus. The Ba-22 isolate, however, having similar characteristics with B. licheniformis.

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

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Huan Peng

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

Relationship between production, nematodes and "redness" in strawberries

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Paula Nogueira Curi

2016-08-01

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

Hybridization and polyploidy enable genomic plasticity without sex in the most devastating plant-parasitic nematodes.

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Romain Blanc-Mathieu

2017-06-01

Full Text Available Root-knot nematodes (genus Meloidogyne exhibit a diversity of reproductive modes ranging from obligatory sexual to fully asexual reproduction. Intriguingly, the most widespread and devastating species to global agriculture are those that reproduce asexually, without meiosis. To disentangle this surprising parasitic success despite the absence of sex and genetic exchanges, we have sequenced and assembled the genomes of three obligatory ameiotic and asexual Meloidogyne. We have compared them to those of relatives able to perform meiosis and sexual reproduction. We show that the genomes of ameiotic asexual Meloidogyne are large, polyploid and made of duplicated regions with a high within-species average nucleotide divergence of ~8%. Phylogenomic analysis of the genes present in these duplicated regions suggests that they originated from multiple hybridization events and are thus homoeologs. We found that up to 22% of homoeologous gene pairs were under positive selection and these genes covered a wide spectrum of predicted functional categories. To biologically assess functional divergence, we compared expression patterns of homoeologous gene pairs across developmental life stages using an RNAseq approach in the most economically important asexually-reproducing nematode. We showed that >60% of homoeologous gene pairs display diverged expression patterns. These results suggest a substantial functional impact of the genome structure. Contrasting with high within-species nuclear genome divergence, mitochondrial genome divergence between the three ameiotic asexuals was very low, signifying that these putative hybrids share a recent common maternal ancestor. Transposable elements (TE cover a ~1.7 times higher proportion of the genomes of the ameiotic asexual Meloidogyne compared to the sexual relative and might also participate in their plasticity. The intriguing parasitic success of asexually-reproducing Meloidogyne species could be partly explained by

Efeitos de diferentes níveis de matéria orgânica no solo e de inóculo sobre a interação planta-Meloidogyne spp. e a produção massal de Pasteuria penetrans Effects of cow manure levels in the soil and inoculum concentration on the plant-Meloidogyne spp. interaction and on the mass production of Pasteuria penetrans

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Fábio Ramos Alves

2007-12-01

Full Text Available Foram estudados os efeitos de quatro proporções de esterco de curral no solo, 0, 20, 33 e 50% (V:V, e três níveis de inóculo de Meloidogyne spp. (3.000, 6.000 e 9.000 J2 por planta na concentração de fenóis em raízes de tomateiro, no desenvolvimento das fêmeas, nas células gigantes induzidas por esses patógenos e na infecção e reprodução de Pasteuria penetrans. O experimento foi conduzido em casa-de-vegetação, em delineamento inteiramente ao acaso com doze repetições, sendo avaliado 50 dias após a inoculação das plantas. O tamanho médio das fêmeas do nematóide foi maior quando as plantas foram inoculadas com 3.000 J2. Maior percentual de fêmeas infectadas por P. penetrans foi observado quando não se utilizou esterco no substrato ou quando as plantas foram inoculadas com 3.000 J2. As plantas inoculadas com 9.000 J2 e cultivadas no substrato com 20% de esterco foram as que produziram mais endósporos. A concentração de fenóis nas raízes aumentou à medida que se acrescentou esterco de curral ao substrato. As células gigantes de plantas cultivadas no substrato com 33 e 50% de esterco apresentaram menores número, tamanho e quantidade de núcleos. O aumento da proporção de esterco de curral ao substrato causou aumento nas concentrações de fenóis nas raízes, fato que foi deletério às células gigantes, prejudicial ao desenvolvimento do nematóide e à reprodução de P. penetrans.The effects of four different proportions of cow manure, 0, 20, 33 and 50% (V:V and three Meloidogyne spp. inoculum levels (3,000; 6,000 and 9,000 J2 per plant on the phenol concentration in the tomato roots, in the nematode female development, the giant cells induced by the nematode and on the reproduction of Pasteuria penetrans were investigated. The experiment was carried out in greenhouse, in a completely randomized design with twelve replicates, and evaluated 50 days after inoculation. The size of nematode females was higher when

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

Science.gov (United States)

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

2016-01-01

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

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characteristics. Biopesticides were ... These biologically active factors exhibit the property to re .... soil microbes, such as phenazine-type antibiotics or hydrogen .... nematodes, M. incognita infestation and growth of tomato ..... Eucalyptus,.

Estudo da eficácia in vitro e in vivo de bioterápicos e produtos naturais no controle de Rhipicephalus microplus (Canestrini, 1887) e sua relação com o bem-estar animal

OpenAIRE

Paula Pimentel Valente

2014-01-01

O Rhipicephalus microplus causa perdas significativas à pecuária bovina e os prejuízos aumentam proporcionalmente ao desenvolvimento de resistência aos principais acaricidas. Neste cenário, a homeopatia e a fitoterapia têm despontado como possibilidades terapêuticas para o controle deste ixodídeo. Este trabalho teve por objetivo o desenvolvimento de bioterápicos, realizar triagem de substâncias naturais bioativas contra R. microplus e avaliar eficácia em bovinos artificialmente infestados. Co...

Characterization of soil suppressiveness to root-knot nematodes in organic horticulture in plastic greenhouse

Directory of Open Access Journals (Sweden)

Ariadna eGiné

2016-02-01

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

Demodex spp. EN PERROS CON DEMODICOSIS, EN UNA REGIÓN DE CUBA

OpenAIRE

Guerra, Yunaisy; Mencho, J.D; Rodríguez Diego, J.G; Marín, E; Olivares, J.L

2010-01-01

Con el objetivo de determinar las características morfométricas del género Demodex, en perros con demodicosis, de una región cubana, se muestrearon 571 perros afectados por demodicosis. Se realizó el estudio morfométrico de ejemplares adultos y sus huevos, provenientes de animales naturalmente infestados. Por primera vez se comunica en Cuba, la presencia de una variedad fenotípica de Demodex diferentes a D. canis. In order to determine the morfometric characteristics of the genus Demodex o...

In the Arab Bedroom: The Sex Life of Arabs.

Science.gov (United States)

Dupont, P

2016-12-01

The sex life of Arabs is terra incognita for scientists and policy makers. Shereen El Feki's book "Sex and the Citadel" is the first serious attempt to chart sexual intimacy in the rapidly changing Arab world.

Efeito da solarização, adubação química e orgânica no controle de nematóides em alface sob cultivo protegido Effect of solarization, chemical and organic fertilization on the control of nematode on greenhouse lettuce

Directory of Open Access Journals (Sweden)

Marlene G da Silva

2006-12-01

Full Text Available Os efeitos da solarização do solo associados à adubação no controle de nematóides e na produtividade da alface cultivar "Verônica" foram avaliados em solo naturalmente infestado. Dois experimentos foram conduzidos, um com e outro sem solarização, em casa de vegetação, ambos com cinco tratamentos: adubação orgânica; nitrogênio na forma amoniacal (NH4; adubação com NPK; adubação orgânica mais NPK; testemunha (sem adubação. No experimento solarizado, o solo foi coberto durante 132 dias com filme plástico transparente. A população de nematóides foi avaliada em duas camadas (0-10 cm e 10-20 cm, e as coletas de solo foram feitas em três épocas (antes da implantação do experimento; após a solarização; após a colheita. O delineamento experimental foi o de blocos ao acaso com três repetições em parcelas sub-subdivididas, com medidas no espaço e no tempo (5 adubações x 2 camadas x 3 épocas, e a comparação entre experimentos foi feita pela análise conjunta. O efeito da solarização sobre o controle de nematóides dependeu da adubação e camada do solo. A solarização reduziu a população de nematóides na camada de 0-10 cm em todos os tratamentos de adubação. A solarização associada ao NH4 reduziu a diversidade na camada de 10-20 cm. A solarização combinada às adubações orgânica, N-NH4, NPK e orgânica mais NPK reduziu de maneira eficiente o número de galhas, o número de massas de ovos e a população de nematóides fitoparasitas nas raízes, em especial de Meloidogyne spp. Solarização combinada à adubação orgânica apresenta potencial para controle de nematóides e redução do uso de agrotóxicos.The effect of soil solarization and fertilization was evaluated for nematode control in 'Veronica' lettuce in naturally infested soil. The two greenhouse experiments consisted of five fertilization treatments: organic fertilization; ammoniacal nitrogen (ammonium sulphate; NPK fertilization; organic

In the Arab Bedroom: The Sex Life of Arabs

OpenAIRE

Dupont, P

2017-01-01

Abstract The sex life of Arabs is terra incognita for scientists and policy makers. Shereen El Feki?s book ?Sex and the Citadel? is the first serious attempt to chart sexual intimacy in the rapidly changing Arab world.

Evaluación del efecto residual del temephos en larvas de Aedes aegypti en Lima, Perú

OpenAIRE

Palomino S, Miriam; Centro Nacional de Salud Pública, Instituto Nacional de Salud. Lima, Perú.; Solari, Lely; Centro Nacional de Salud Pública, Instituto Nacional de Salud. Lima, Perú. Hospital Nacional Hipólito Unánue. Lima, Perú.; León C, Walter; Centro Nacional de Salud Pública, Instituto Nacional de Salud. Lima, Perú.; Vega H, Rosario; Centro Nacional de Control de Calidad, Instituto Nacional de Salud. Lima, Perú.; Vergaray C, Máximo; Centro Nacional de Control de Calidad, Instituto Nacional de Salud. Lima, Perú.; Cubillas, Luis; Dirección de Salud Lima Norte III, Ministerio de Salud. Lima, Perú.; Mosqueda C, Rosa; Centro Nacional de Control de Calidad, Instituto Nacional de Salud. Lima, Perú.; García A, Norma; Centro Nacional de Control de Calidad, Instituto Nacional de Salud. Lima, Perú.

2006-01-01

El temephos ha sido usado como la única estrategia de control para Aedes aegypti en Lima durante los últimos años. Objetivo: Evaluar la eficacia residual de temephos para el control de Ae. aegypti en condiciones de campo y laborato - rio en Lima, Perú. Materiales y métodos: Se eligieron ocho tanques bajos de concreto (TBC) depósitos predominan - temente infestados con Ae. aegypti en el distrito de San Juan de Lurigancho, situado al norte del área suburbana de Lima. Se cuantificó el número de ...

Panstrongylus megistus em ecótopos artificiais de ilhas do Alto Rio Paraná

Directory of Open Access Journals (Sweden)

Guilherme Ana Lucia Falavigna

2001-01-01

Full Text Available Em resposta a denúncias de triatomíneos em ilhas do Alto Rio Paraná foram investigados 145 ecótopos artificiais e 4 (2,8% deles encontravam-se infestados: residência, "clube", ex-escola e monte de madeira. Foram analisados 17 de 35 P. megistus coletados; 12 (70,6% apresentavam-se infectados por Trypanosoma cruzi. Ave e roedor constituíram as fontes alimentares mais comuns. Todos os exames sorológicos (56 de humanos, 18 de cães e 10 de gatos foram negativos.

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

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Hongwei Xie

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

[Diversity of actinomycetes associated with root-knot nematode and their potential for nematode control].

Science.gov (United States)

Luo, Hong-li; Sun, Man-hong; Xie, Jian-ping; Liu, Zhi-heng; Huang, Ying

2006-08-01

Twenty actinomycetes were isolated from root-knot nematode eggs and females collected from 11 plant root samples infested by Meloidogyne spp.. The isolates were assigned to the genera Streptomyces, Nocardia and Pseudonocardia respectively, based on analysis of morphological characteristics, cell-wall DAPs and 16S rRNA gene sequences. 80% of them were streptomycetes. Biocontrol potential of the isolates against Meloidogyne hapla was evaluated in liquid culture in vitro. The average percentages of egg parasitism, egg hatching, and juvenile mortality were 54.1, 40.4 and 26.2, respectively. Three Streptomyces strains and one Nocardia strain with high pathogenicity in vitro were selected to determine their ability to reduce tomato root galls in greenhouse. The results demonstrated good biocontrol efficacy (31.4%-56.4%) of the strains.

Molecular marker screening of peanut ( Arachis hypogaea L ...

African Journals Online (AJOL)

Molecular marker screening of peanut (Arachis hypogaea L.) germplasm for Meloidogyne arenaria resistance. V Carpentieri-Pipolo, M Gallo-Meagher, DW Dickson, DW Gorbet, M de Lurdes Mendes, SG Hulse de Souza ...

Evaluation of nematicidal action of some bio-agents and botanicals ...

African Journals Online (AJOL)

These biologically active factors exhibit the property to resist against M. incognita. Different concentrations for each treatments were used and analysis for the efficiency of bio pesticides was made effect of these concentrations were perceived on egg hatchability, gall formation, number of eggs, final nematode population, ...

Nuclear Structure Near the Drip Lines

International Nuclear Information System (INIS)

Nazarewicz, W.

1998-01-01

Experiments with beams of unstable nuclei will make it possible to look closely into many aspects of the nuclear many-body problem. Theoretically, exotic nuclei represent a formidable challenge for the nuclear many-body theories and their power to predict nuclear properties in nuclear terra incognita

Efecto de la Infección de Spongospora subterranea f. sp. subterranea en Hospederos Alternos / Effect of Spongospora subterranea f. sp. subterranea Infection on Alternate Hosts

OpenAIRE

Ivón Magaly Arcila Aristizábal; Elena Paola González Jaimes; Catalina María Zuluaga Amaya; Mauricio Alejandro Marín Montoya; José Miguel Cotes Torres

2014-01-01

Resumen. Como una de las posibles medidas de manejo deaplicación práctica para la reducción de inóculo de Spongospora subterranea f. sp. subterranea en suelos infestados con quistosoros del patógeno, se evaluó la incidencia de su infección en diferentes plantas hospederas durante tres siembras consecutivas. Las siembras se realizaron en macetas que contenían 2 kg de suelo previamente inoculados con una concentración de 1x105quistosoros.g-1 de suelo; las cosechas de las plantas se realizaron c...

Resultados de un proceso de capacitación e innovación participativas para la adopción del manejo agroecológico de la broca del café en Cuba

OpenAIRE

Vázquez Moreno, Luis L.; Murguido, Carlos; Navarro, Aurelio; García, Mario

2010-01-01

La broca del café (Hypothenemus hampei) se ha convertido en la principal plaga de este cultivo en el país desde mediados de los años noventa y para su manejo se ha utilizado el insecticida endosulfán, la eliminación de frutos infestados y el uso del hongo entomopatógeno Beauveria bassiana, entre otras prácticas. Debido a la necesidad de transitar hacia la caficultura sostenible, se realizó un proyecto de innovación y capacitación participativas para lograr la adopción de prácti...

Prevalence of Colacium vesiculosum (Colaciales: Euglenophyceae on planktonic crustaceans in a subtropical shallow lake of Argentina

Directory of Open Access Journals (Sweden)

Yolanda Zalocar

2011-09-01

Full Text Available Colacium vesiculosum (Euglenophyceae is an epibiont common on planktonic microcrustaceans of continental waters. The interaction between epibionts and substrate organisms is not very well known, particularly in subtropical environments of South America. In the present work, we analyzed the prevalence, density, biomass and attachment sites of C. vesiculosum on planktonic microcrustaceans from Paiva Lake, a subtropical lake of Argentina. With the aim to evaluate whether epibionts affect the filtering rates of Notodiaptomus spiniger, the dominant planktonic crustacean, we carried out bioassays using phytoplankton Colacium vesiculosum Ehrenberg (Euglenophyceae es un epibionte común en microcrustáceos del plancton de aguas continentales. La interacción epibiontes y organismo substrato es poco conocida, particularmente en ambientes subtropicales de América del Sur. Se analiza la prevalencia, densidad, biomasa y sitios de adhesión de C. vesiculosum en microcrustáceos planctónicos de un lago subtropical de Argentina. Con el fin de evaluar si los epibiontes afectan la tasa de filtración de Notodiaptomus spiniger Brian, crustáceo dominante del zooplancton, se realizaron bioensayos utilizando el fitoplancton <53µm. Los crustáceos fueron muestreados con un tubo de PVC (1m de largo, 10cm de diámetro filtrándose 50L de agua a través de una red de 53µm de abertura de malla. El recuento de los microcrustáceos se realizó en cámaras de Bogorov bajo microscopio estereoscópico. Los organismos infectados fueron separados y observados al microscopio fotónico para determinaciones de densidad y biovolumen de los epibiontes, y su distribución en el exoesqueleto. La prevalencia de C. vesiculosum fue mayor en crustáceos adultos que en estadíos larvales y juveniles. El grupo más infestado fue el de los copépodos calanoideos en relación con su alta densidad. Los sitios de adhesión sobre el exoesqueleto fueron las regiones del cuerpo que durante la

Early Signs of Entrepreneurial Giftedness

Science.gov (United States)

Shavinina, Larisa V.

2008-01-01

Although successful entrepreneurship is important for the economic prosperity of any society, one should acknowledge that entrepreneurial giftedness is terra incognita from a research viewpoint. This article analyzes early manifestations of entrepreneurial giftedness in the cases of Richard Branson, Michael Dell, and Bill Gates and thus opens a…

A Description of the Framework of the Atmospheric Boundary Layer Environment (ABLE) Model

Science.gov (United States)

2012-09-01

between soil, urban, vegetation , and/or surface water and the atmosphere and radiation. We seek to fill a gap in Army capabilities by developing a...the Atmosphere; Cambridge Univ. Press, 393 pp, 2010. Wyngaard, J. C. Toward Numerical Modeling in the “ Terra Incognita.” Journal of Atmospheric

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

International Nuclear Information System (INIS)

Guzman Piedrahita, Oscar Adrian; Castano Zapata, Jairo

2010-01-01

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

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

Science.gov (United States)

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

2016-04-01

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

evaluation of tomato genotypes for resistance to root-knot

African Journals Online (AJOL)

Prof. Adipala Ekwamu

Tomato production in Ghana is threatened by plant parasitic nematodes, especially the root knot ... to be highly resistant to Meloidogyne spp. and also recorded the lowest reproductive factors of 0.71 and 0.53, respectively. ..... VII International.

Distribution and Prevalence of Parasitic Nematodes of Cowpea (Vigna unguiculata) in Burkina Faso.

Science.gov (United States)

Sawadogo, A; Thio, B; Kiemde, S; Drabo, I; Dabire, C; Ouedraogo, J; Mullens, T R; Ehlers, J D; Roberts, P A

2009-06-01

A comprehensive survey of the plant parasitic nematodes associated with cowpea (Vigna unguiculata) production fields was carried out in the three primary agro-climatic zones of Burkina Faso in West Africa. Across the three zones, a total of 109 samples were collected from the farms of 32 villages to provide a representative coverage of the cowpea production areas. Samples of rhizosphere soil and samples of roots from actively growing cowpea plants were collected during mid- to late-season. Twelve plant-parasitic nematode genera were identified, of which six appeared to have significant parasitic potential on cowpea based on their frequency and abundance. These included Helicotylenchus, Meloidogyne, Pratylenchus, Scutellonema, Telotylenchus, and Tylenchorhynchus. Criconemella and Rotylenchulus also had significant levels of abundance and frequency, respectively. Of the primary genera, Meloidogyne, Pratylenchus, and Scutellonema contained species which are known or suspected to cause losses of cowpea yield in other parts of the world. According to the prevalence and distribution of these genera in Burkina Faso, their potential for damage to cowpea increased from the dry Sahelian semi-desert zone in the north (annual rainfall < 600 mm/year), through the north-central Soudanian zone (annual rainfall of 600-800 mm/year), to the wet Soudanian zone (annual rainfall ≥ 1000 mm) in the more humid south-western region of the country. This distribution trend was particularly apparent for the endoparasitic nematode Meloidogyne and the migratory endoparasite Pratylenchus.

Resistentie tegen het maiswortelknobbelaaltje in bladrammenas

NARCIS (Netherlands)

Visser, J.H.M.

2009-01-01

Het niveau van resistentie van bladrammenasrassen tegen het maiswortelknobbelaaltje, Meloidogyne chitwoodi, kan op meerdere manieren worden bepaald. Om het resistentieniveau van rassen objectief vast te kunnen stellen, is een betrouwbare en door een onafhankelijke instantie uit te voeren

Perilous terra incognita--open-access journals.

Science.gov (United States)

Balon, Richard

2014-04-01

The author focuses on a new rapidly spreading practice of publication in open-access journals. The pros and cons of open-access journals are discussed. Publishing in these journals may be cost prohibitive for educators and junior faculty members. Some authors may be lured by the ease of publishing in open-access journals (and their, at times, inflated self-description, e.g., "international", "scientific"), and their possibly valuable contributions will escape the attention of Academic Psychiatry readership in the vast sea of open-access journals. The readership may be flooded with a large number of low-quality articles (maybe not even properly peer-reviewed) from open-access journals. It may take some time to sort out what is and what is not relevant and useful. Open-access publishing represents a problematic and controversial practice and may be associated with a conflict of interest for the editors and publishers of these journals.

Wittgensteins ‘Lebensform’: een terra incognita?

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Eijzenga, H.

1995-01-01

In dit artikel heb ik gesteld dat de dilemma’s ten aanzien van culturele incommensurabiliteit waarmee zowel universalisten als relativisten te maken krijgen vermeden kunnen worden door uitwerking van Wittgensteins ‘übersichtliche Darstellung’ (overzichtelijke weergave) waarmee Wittgenstein in

Molecular marker screening of peanut (Arachis hypogaea L ...

African Journals Online (AJOL)

SAM

2014-06-25

Jun 25, 2014 ... the genomic DNA, the frozen samples were ground and DNA was extracted .... RFLP analysis, no evidence of segregation was found in ... Figure 1. RFLP locus R2430E linked to resistance to Meloidogyne arenaria in peanut.

Resonance – Journal of Science Education | Indian Academy of ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 7. Gödel's Explorations in Terra Incognita. Vijay Chandru. General Article Volume 6 Issue 7 July 2001 pp 22-28. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/006/07/0022-0028. Author Affiliations.

Biocontrol (Formulation of Bacillus firmus (BioNem)) of Root-knot ...

African Journals Online (AJOL)

pathogens and viruses and 6 economically important insect and mite pests attacking ... biological control have been tried with different levels of successes in tomato .... At Dire Dawa, the soil application of BioNem at the rates 200 and 400 ... hatching of M. incognita and BioNem at 2.5 % and 3% concentrations caused 100 ...

Detecting genotypic variation among the single spore isolates of Pasteuria penetrans population occuring in Florida using SNP-based markers

Science.gov (United States)

Pasteuria penetrans is a naturally occurring soil-borne endospore-forming bacterium, which functions as a castrating parasite of plant-parasitic nematodes belonging to the genus Meloidogyne. Pasteuria penetrans is established as an effective biological control agent for control and management o...

Plant Products Research Journal - Vol 15 (2011)

African Journals Online (AJOL)

Host-Parasite Relationship Between African Yam Bean, Sphenostylis stenocarpa (Hochst. Ex. A. Rich) Harms Accessions and Meloidogyne ... Effect of Processing on the Elemental Composition of Selected Leafy Vegetables · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Contr rol of r root-kn saw not nem wdust matod in tom e by u mato ro ...

African Journals Online (AJOL)

SAM

proved with visualizing mical level a ot-knot nema ard dust ame dust. by- and accum ..... Table 2. Effect of sawdust on length of shoot and root (cm) of tomato plants. ...... Evaluation of powdered pine bark for control of Meloidogyne arenaria.

Diagnóstico y dinámica poblacional de nematodos fitoparásitos en dos sistemas de cultivos de piña en Costa Rica

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Tomás de Jesús Guzmán-Hernández

2014-05-01

Full Text Available La presente investigación determinó la presencia de géneros, densidad de población y dinámica poblacional de nematodos fitoparásitos en plantaciones de piña (Ananas comosus, var. comosus en dos sistemas de cultivos en Costa Rica, período 2006-2008. El estudio comprendió un diagnóstico a nivel de suelo y raíz en plantas de dos a doce meses de edad que permitiera la determinación de la dinámica poblacional de los nematodos en los diferentes lotes cultivados de piña, durante el lapso de tiempo señalado en sistemas de cultivos convencionales y orgánicos en las regiones Huetar Norte y Huetar Atlántica de Costa Rica. Se seleccionaron lotes comerciales, los cuales fueron muestreados una vez al mes durante febrero a diciembre en los años 2006-2008. Se caracterizaron y cuantificaron los géneros de nematodos encontrados. El diagnóstico permitió la identificación de siete géneros a nivel de suelo: Helicotylenchus spp., Meloidogyne spp., Pratylenchus spp., Tylenchus, Tylenchorhychus, nematodos depredadores y de vida libre, donde el género Helicotylenchus spp. el que se indentificó con más frecuencia. La mayor población de nematodos fitoparásitos fue observada a nivel de suelo y correspondió a los géneros Pratylenchus spp. y Helicotylenchus spp. Los nematodos más frecuentemente observados en raíces de plantas de piña bajo técnicas orgánicas fueron: Criconemella spp., Helicotylenchus spp., Pratylenchus spp.; en el suelo se presentaron Helicotylenchus spp., y Pratylenchus spp., con frecuencias del 100%. En raíz y suelo de plantas de piña bajo técnicas convencionales el género Helicotylenchus spp. ,fue el más frecuente. El género Pratylenchus spp. presentó la densidad poblacional promedio más alta en la raíz en sistemas orgánicos y convencionales con 1.009,83 y 1.075,22 ind/100 g de raíz, respectivamente. En las áreas de manejo orgánico se presentó una mayor diversidad de géneros de nematodos en la raíz de la

The parasitism of Ixodes luciae (Acari: Ixodidae on marsupials and rodents in Peruvian Amazon O parasitismo do Ixodes luciae (Acari: ixodidae em marsupiais e em roedores na Amazônia Peruana

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María Mónica Díaz

2009-01-01

Full Text Available In this work the infestation with I. luciae on Didelphimorphia and Rodentia in different environments of Peruvian Amazon was studied. Didelphimorphia was represented by the family Didelphidae. Specimens belonging to Caluromys lanatus, Didelphis marsupialis, Marmosops sp.2, Metachirus nudicaudatus, Philander andersoni and Philander opossum were infested with adults I. luciae and one Micoureus sp. was infested with larvae. In Rodentia, the infestation with I. luciae nymphs was restricted to Hylaeamys perenensis, Hylaeamys yunganus and Oligoryzomys microtis, while one Oecomys bicolor (all Cricetidae was infested with larvae of this species. The few larvae were found on rodents captured in primary forest. The only significant difference (P No presente trabalho, infestações por Ixodes luciae em Didelphimorphia e Rodentia em diferentes ambientes da Amazônia peruana foram estudadas. Didelphimorphia foi representada pela família Didelphidae. Espécimes pertencentes a Caluromys lanatus, Didelphis marsupialis, Marmosops sp., Metachirus nudicaudatus, Philander andersoni e Philander opossum foram encontrados infestadas por adultos de I. luciae; um Micoureus sp. foi encontrado infestado por larvas. Em Rodentia, a infestação por ninfas de I. luciae estiveram restritas a Hylaeamys perenensis, Hylaeamys yunganus e Oligoryzomys microtis, enquanto que um Oecomys bicolor (todos Cricetidae esteve infestado por larvas de I. luciae. As poucas larvas foram encontradas em roedores capturados na floresta primária. A única diferença significante (P < 0.05 na prevalência de carrapatos adultos em Didelphimorphia foi entre P. andersoni e M. nudicaudatus (distribuição chi-quadrado. A distribuição de carrapatos adultos foi significativamente diferente em P. andersoni quando comparado com M. nudicaudatus, P. opossum e D. marsupialis (teste Kruskal-Wallis. Nenhum efeito significante do mês ou ambiente foi observado em relação à infestação por carrapato

Dissecting host plant manipulation by cyst and root-knot nematodes

NARCIS (Netherlands)

Karczmarek, A.

2006-01-01

Cyst ( Globodera spp. and Heterodera spp.) and root-knot nematodes ( Meloidogyne spp.), one of the most damaging crop pests, are a perfect example of highly adapted, sophisticated root parasites. These nematodes induces specialized feeding structures (cyst

Phylogency and Evolution of Nematodes

NARCIS (Netherlands)

Bert, W.; Karssen, G.; Helder, J.

2011-01-01

Many plant-parasitic nematodes including members of the genera Meloidogyne (root-knot nematodes), Heterodera and Globodera (cyst nematodes) and Pratylenchus (lesion nematodes) are studied as they cause major damage to crops such as potato, tomato, soybean and sugar beet. Both for fundamental reasons

Pasteuria spp.: Systematics and Phylogeny of These Bacterial Parasites of Phytopathogenic Nematodes.

Science.gov (United States)

Preston, J F; Dickson, D W; Maruniak, J E; Nong, G; Brito, J A; Schmidt, L M; Giblin-Davis, R M

2003-06-01

Pasteuria spp. include endospore-forming bacterial pathogens of cladoceran crustaceans and plant-parasitic nematodes. Propagation of these nematode pathogens requires attachment of soilborne endospores to nematode hosts, infection, growth, sporulation, and release of endospores to repeat the cycle of infection and propagation. The ability of these bacteria to suppress the levels of plant-parasitic nematodes in the field has made them particularly promising candidates for biocontrol of nematode diseases of plants. Genes encoding 16S ribosomal RNA have been sequenced for the cladoceran (water flea) parasite and type species, Pasteuria ramosa, and for Pasteuria spp. isolated from root-knot (Meloidogyne arenaria race 1 and Meloidogyne sp.), soybean cyst (Heterodera glycines), and sting (Belonolaimus longicaudatus) nematodes. These have provided a phylogenetic basis for their designation to a distinct clade within the family Alicyclobacillaceae of the gram-positive endospore-forming bacteria. Two apparent biotypes of P. penetrans demonstrating a host preference for different Meloidogyne spp. showed identical 16S rDNA sequences, suggesting host-recognition evolves within a given species. The sequences of genes encoding sporulation transcription factors, sigE and sigF, from P. penetrans biotype P-20 show different phylogenetic relationships to other endospore-forming bacteria, supporting their application to further discriminate Pasteuria spp. and biotypes. Distribution of an adhesin-associated epitope on polypeptides from different Pasteuria isolates provides an immunochemical approach to differentiate species and biotypes with specific host preferences. Application of bioinformatics to genomic data, as well as further characterization of the biochemical basis for host recognition, will facilitate development of Pasteuria spp. as benign alternatives to chemical nematicides.

pmker 24(3)

African Journals Online (AJOL)

HP Pro 2000

L. AFOUDA1, H. BAIMEY2, F. X. BACHABI2, D. H. SERO-KPERA1 et R. BALOGOUN1. 1Faculté ... rates ranging from 20 to 95 % 6 days after exposure. The effect of extracts was found ... integrated management of Meloidogyne spp. Keywords ...

Luta biológica clássica com Hyperaspis pantherina Fürsch (Coleoptera: Coccinellidae no combate à Orthezia insignis Browne (Homoptera: Ortheziidae em jacarandá Biological control with Hyperaspis pantherina Fürsch (Coleoptera: Coccinellidae to control Orthezia insignis Browne (Homoptera: Ortheziidae on blue jacaranda

Directory of Open Access Journals (Sweden)

Ana Paula Félix

2008-12-01

Full Text Available Os jacarandás e várias plantas ornamentais que ornamentam passeios e áreas ajardinadas da cidade do Funchal encontram-se infestados pela cochonilha Orthezia insignis Browne. Para combater esta praga foi importada do Quénia, uma joaninha, Hyperaspis pantherina Fürsch. Este predador é específico de O. insignis e tem sido utilizado, com sucesso em programas de luta biológica, em vários países de África, no Peru, Hawai e na Ilha de Santa Helena. Na Ilha da Madeira, desde Julho de 2002, H. pantherina está a ser criado em laboratório e largado em jacarandás infestados com o objectivo de combater a cochonilha-dojacarandá através da luta biológica clássica. Referem-se as largadas de H. pantherina e o sistema de monitorização adoptado para verificar a aclimatação do predador.The Jacaranda trees and other ornamental plants used in sidewalks and gardenlike areas of sidewalks and other gardened areas of the downton Capital city of Madeira Island (Funchal, are infested by the Jacaranda or Lantana Bug, Orthezia insignis Browne. A ladybird, Hyperaspis pantherina Fürsch, was imported from Kenya to control this pest. This ladybird is a specific predator of O. insignis and it has been used, successfully in biological control programs, in several countries of Africa, in Peru, Hawaii and in Santa Helena Island. In Madeira Island, H. pantherina is being reared in laboratory and released into infested jacarandas since July 2002, in a classical biological control way. The releasing of H. pantherina is described in detail as well as the adopted monitoring system to verify its acclimation.

Intoxicação por Senna occidentalis (Leg. Caesalpinoideae em bovinos em pastoreio

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Barros Claudio S.L.

1999-01-01

Full Text Available São descritos três surtos da intoxicação por Senna occidentalis em bovinos em criação extensiva, exclusivamente em pastoreio, durante o outono e início do inverno, em três estabelecimentos do estado do Rio Grande do Sul. Os bovinos afetados tinham acesso a antigas lavouras de soja ou restevas de lavouras de soja e milho altamente infestados por fedegoso (S. occidentalis. No estabelecimento 1, de um total de 34 novilhas (de aprox. 18 meses de idade, 10 morreram (29,1%; no estabelecimento 2, morreram 9 (4,2% de um total de 212 vacas prenhes e, no estabelecimento 3, morreram 6 (12,0% de um total de 50 animais. O curso clínico variou de 3 a 6 dias, e os sinais clínicos incluíam urina marrom-escura, fraqueza muscular, tremores, andar cambaleante, decúbito esternal e morte. Os animais, mesmo em decúbito, permaneciam alerta e com reflexos normais, alimentando-se e bebendo água até poucas horas antes da morte. No estabelecimento 2, os bovinos começaram a adoecer 7 dias após terem sido retirados do campo infestado pela planta. As principais alterações observadas na necropsia foram áreas claras na musculatura esquelética, principalmente nos músculos dos membros posteriores e estrias esbranquiçadas na musculatura cardíaca. A principal lesão microscópica era de degeneração e necrose nos músculos esqueléticos (miopatia degenerativa tóxica multifocal multifásica. Os dados epidemiológicos, clínicos, de necropsia e histopatológico permitiram concluir pelo diagnóstico de intoxicação por S. occidentalis, nesses três surtos.

Agrosearch

African Journals Online (AJOL)

readily degraded ·'in soil, and has no harmfull effects on soil processes. (ICI,. 19 8 7). The present investigation was therefore carried out to explore the nematicidal p r o p e .r t i e s o £ lambdacyhalothrin against the ' root knot nematode M. incognita on soybeans. The intensive cultivation of soybean ·has often allowed the ...

RNA interference in plant parasitic nematodes

African Journals Online (AJOL)

STORAGESEVER

2008-08-04

Aug 4, 2008 ... grower preference or by government restrictions to limit the environmental ... risks associated with chemical control and (c) the pro- vision of ... certain model organisms. The first ... reproductive system (Lilley et al., 2005b), sperm (Urwin .... interference of dual oxidase in the plant nematode Meloidogyne.

Efficacité des champignons mycorhiziens contre les nématodes ...

African Journals Online (AJOL)

SARAH

30 mai 2015 ... Mots clés : Glomus sp., Lycopersicon esculentum, lutte biologique, Meloidogyne spp. Effectiveness of the arbuscular mycorrhizal fungi on the parasitic nematodes of tomato in Togo. ABSTRACT. Objectives : To find alternatives to the synthetic pesticides used against nematodes the present work aimed at.

Evaluation of tomato genotypes for resistance to root-knot nematodes

African Journals Online (AJOL)

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

Desinfestação de substratos com a utilização de coletor solar Utilization of solar collector for treatment of plant growth substrates

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Raquel Ghini

1992-01-01

Full Text Available Coletores solares planos constituídos de caixas de madeira com canaletas de chapa de alumínio, onde se coloca o substrato e se cobre com plástico transparente, foram testados quanto ao controle de Sclerotium rolfsii, Rhizoctonia solani, Verticillium sp., Meloidogyne arenaria e Cyperus rotundus (tiririca. Dependendo da intensidade de radiação solar, é necessário um dia para desinfestação do substrato com S. rolfsii e dois dias para R. solani, Verticillium sp. e M. arenaria.Flat solar collectors were tested for the control of Sclerotium rolfsii, Rhizoctonia solani, VerticiUium sp., Meloidogyne arenaria and Cyperus rotundus (nut sedge. The equipment developed comprises, basically, gutters of aluminum with termic liner of glass wool and transparent plastic cover. The results showed that, depending upon the solar radiation, one day is required for the disinfestations of substrate infested with S. rolfsii and nut sedge, and two days for R. solani, Verticillium sp. and M. arenaria.

Purificação do flavonóide trans-tilirosídeo do extrato metanólico das folhas de Gochnatia barrosii Cabrera (asteraceae e avaliação da sua atividade nematicida Purification of the flavonoid trans-tiliroside from the methanolic extract of Gochnatia barrosii Cabrera (Asteraceae leaves and evaluation of the nematicidal activity

Directory of Open Access Journals (Sweden)

Helvécio Martins dos Santos Júnior

2010-10-01

Full Text Available O fracionamento do extrato metanólico das folhas de Gochnatia barrosii Cabrera (Asteraceae resultou no isolamento do flavonol glicosídico trans-tilirosídeo [kaempferol 3-O- -D-(6''-O-E-p-cumaroil-glicopiranosídeo], que nunca tinha sido identificado na referida espécie vegetal. Em teste realizado in vitro, observou-se que tal substância a 500 μg/mL, não tem efeito sobre a mortalidade de juvenis do segundo estágio do nematóide Meloidogyne exigua Goeldi.Fractionation of the methanolic extract from Gochnatia barrosii Cabrera (Asteraceae leaves resulted in the isolation of the flavonol glycoside trans-tiliroside [kaempferol 3-O- -D-(6''-O-E-p-coumaroyl-glucopyranoside], which had never been found in such plant species. Such substance at 500 μg/mL caused no in vitro effect on the mortality of second-stage juveniles of the nematode Meloidogyne exigua Goeldi.

The added value of proficiency tests: choosing the proper method

NARCIS (Netherlands)

Nijs, den A.P.M.; Berg, van den W.

2013-01-01

To gain insight into the different extraction processes used in laboratories in various European countries and the effect these methods might have on the number of Meloidogyne second-stage juveniles (J2) extracted from soil samples, a ring test with 2 elements was conducted. The first element used

Field evaluation of deficit irrigation effects on tomato growth ...

African Journals Online (AJOL)

Two field experiments were conducted using a common tomato cultivar (GS12) to assess the effect of deficit irrigation (DI) regimes on tomato growth performance, and on root-knot nematode Meloidogyne javanica galling and abundance. Irrigation treatments consisted of five irrigation regimes: 20%, 40%, 60%, 80% and ...

AN 11-YEAR FIELD STUDY WITH PASTEURIA PENETRANS: LESSONS LEARNED THE HARD WAY.

Science.gov (United States)

Beginning in 1998, a bioassay using second-stage juveniles (J2) from a greenhouse (GH) population of the root-knot nematode Meloidogyne arenaria (Ma) was used to monitor endospore densities of the bacterium Pasteuria penetrans, which was parasitizing Ma in a long-term rotation study (begun in 1991)....

Bacterial microbiome and nematode occurrence in different potato agricultural soils

Science.gov (United States)

Pratylenchus neglectus and Meloidogyne chitwoodi are the main plant-parasitic nematodes in potato crops of the San Luis Valley, Colorado. Bacterial microbiome (16S rRNA copies per gram of soil) and nematode communities (nematodes per 200 gr of soil) from five different potato farms were analyzed to ...

Statistical analysis of nematode counts from interlaboratory proficiency tests

NARCIS (Netherlands)

Berg, van den W.; Hartsema, O.; Nijs, Den J.M.F.

2014-01-01

A series of proficiency tests on potato cyst nematode (PCN; n=29) and free-living stages of Meloidogyne and Pratylenchus (n=23) were investigated to determine the accuracy and precision of the nematode counts and to gain insights into possible trends and potential improvements. In each test, each

Browse Title Index

African Journals Online (AJOL)

Items 9851 - 9900 of 11090 ... Vol 10, No 39 (2011), Studies on Buddleja asiatica antibacterial, antifungal, antispasmodic and Ca++ antagonist activities, Abstract PDF. F Ali, I Ali, HU Khan, AU Khan, AH Gilani. Vol 9, No 22 (2010), Studies on Meloidogyne javanica infestation on roma tomato (Lycopersicon esculentum Mill) ...

Evaluación de la actividad biocontroladora de Arthrobotrys sp. y Paecilomyces sp. sobre Meloidogyne javanica in vitro y bajo condiciones de invernadero en crisantemo (Drendranthema grandiflora Andernson

Directory of Open Access Journals (Sweden)

Dávila Lida

2005-06-01

Full Text Available

Para evaluar la acción biocontroladora de Arthrobotrys sp. y Paecilomyces sp. sobre huevos y larvas de Meloidogyne javanica en crisantemo, se realizaron prue­bas in vitro y en invernadero. Se tomaron 500 larvas y 500 huevos del nematodo contenidos en suspensiones de agua estéril y se trataron con concentraciones de 1,3· 106; 1,4· 107 y 6,4· 106; 1,14· 107 conidias/mL de Arthrobotrys sp. y Paecilomyces sp. Se observó bajo estereos­copio cada 24 horas, mientras la acción de los hongos sobre M. javanica se cuantificó a las 72 horas de incu­bación, con un índice de control mayor de 50% sobre larvas y huevos. En invernadero se sembraron esquejes en suelo con compost estéril bajo un diseño estadístico de bloques completos al azar. Los tratamientos fueron: hongos de forma individual y combinada; compost sólo y combinado con cada hongo; carbofurán (Fura­dan®; testigo patógeno y testigo absoluto. A los 45 días después de la inoculación se evaluó el peso fresco de la raíz, la longitud de la raíz, el número de nódulos y el de individuos de M. javanica ambulatorios en 100 g de suelo. Mediante la prueba de Duncan (5% se determi­nó que el tratamiento de hongos en forma combinada controló a M. javanica, con un promedio de 18 nódulos en raíz, y fue menos eficiente comparado con el control individual, con un promedio de 7 y 8 nódulos en raíz respectivamente a los 45 días de transcurrida la infec­ción. El compost no ejerció control sobre M. javanica pues presentó un promedio de 50 nódulos en raíz; el tratamiento (Furadán® exhibió un promedio de 25 nó­dulos en raíz, mostrando diferencias

Characterization of the psoRPM1 gene for resistance to root-knot ...

African Journals Online (AJOL)

Several root-knot nematode (Meloidogyne spp.) resistance genes have been discovered in different stone fruit crops. However, none of them has yet been cloned and they were only located on the chromosomes. In this study, a candidate root-knot nematode resistance gene (designated as psoRPM1) was isolated from the ...

Zelleriella bromelicola, sp. n. (Protozoa: Opalinatea: Entozoário de Aparasphenodon brunoi Miranda-Ribeiro, 1920 (Anura, Hylidae de Ubatuba, São Paulo, Brasil

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Ismael Gióia

1988-01-01

Full Text Available Descreve-se Zelleriella bromelicola, sp. n., achada na região cecal do hilídeo Aparasphenodon brunoi Miranda-Ribeiro, infestado naturalmente com Entamoeba paulista. A célula é ovóide (105,7 um ± 1,6 x 79,3 um ± 1,9 e o núcleo tem uma massa fragmentada semi-paralela (3-5 nucléolos.Zelleriella bromelicola, sp. n., is described, from the caecal region of the hylid frog Aparasphenodon brunoi Miranda-Ribeiro, naturally infected with Entamoeba paulista. The cell is ovoid (105.7 um ± 1.6 x 79.3 um ± 1.9 and the nucleus (15.9 um ± 0.4 has a fragmented semi-parallel mass (3-5 nucleoli.

Relationships between M. enterolobii and F. solani: spatial and temporal dynamics in the occurrence of guava decline

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Vicente Martins Gomes

2014-08-01

Full Text Available Guava decline, caused by the interaction between the phytonematode Meloidogyne enterolobii and the fungus Fusarium solani, has caused direct and indirect losses to the whole productive chain of guava. Aiming to understand the interaction mechanisms between M. enterolobii and F. solani, this study carried out a bioassay on guava plants with roots in two different treatments: inoculated separatelyor together with the fungus and/or nematode. The nematode parasitism not triggered an systemic effect on the plant become susceptible to root rot caused by the fungus.Therefore, it was concluded that there was a local effect of parasitism by M. enterolobii on the pathogenicity of F. solani in guava roots, making it necessary for the two pathogens to occupy the same space at the same time for occurrence of guava decline. Keywords: complex disease, Fusarium solani, guava root-knot nematode, Meloidogyne enterolobii, Psidium guajava. Cite as Gomes VM, Souza RM, Almeida AM, Dolinski C. Relationships between M. enterolobii and F. solani: spatial and temporal dynamics in the occurrence of guava decline.

Numerical experiments with assimilation of the mean and unresolved meteorological conditions into large-eddy simulation model

OpenAIRE

Esau, Igor

2010-01-01

Micrometeorology, city comfort, land use management and air quality monitoring increasingly become important environmental issues. To serve the needs, meteorology needs to achieve a serious advance in representation and forecast on micro-scales (meters to 100 km) called meteorological terra incognita. There is a suitable numerical tool, namely, the large-eddy simulation modelling (LES) to support the development. However, at present, the LES is of limited utility for applications. The study a...

Italian Foreign Policy: Trends for the Twenty-First Century

Science.gov (United States)

2003-06-01

without the love and support of my wife, Dr. Lucia Mariani. While my time at NPS marks only another episode in the unfailing support she has always... della Sinistra). In this transformation, however, the PDS lost support from the hard line Marxists that had supported the PCI. “The split between...Milan, FrancoAngeli, 1998), 95-113. 107 Lucio Caracciolo, Terra Incognita: Le radici geopolitiche della crisi italiana, (Rome, Gius. Laterza and

Evaluación del efecto residual del Temephos en larvas de Aedes aegypti en Lima, Perú

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Miriam Palomino S

2006-07-01

Full Text Available El temephos ha sido usado como la única estrategia de control para Aedes aegypti en Lima durante los últimos años. Objetivo: Evaluar la eficacia residual de temephos para el control de Ae. aegypti en condiciones de campo y laboratorio en Lima, Perú. Materiales y métodos: Se eligieron ocho tanques bajos de concreto (TBC depósitos predominantemente infestados con Ae. aegypti en el distrito de San Juan de Lurigancho, situado al norte del área suburbana de Lima. Se cuantificó el número de larvas con ayuda de una red de mano y luego fueron devueltas a los TBC. Los TBC fueron tratados con temephos a una dosis de 1 ppm en el día cero (0. Se evaluó la mortalidad de las larvas salvajes a 24, 48 y 72 horas y se hizo un seguimiento periódico cada siete días hasta las 14 semanas. Al mismo tiempo y en forma semanal se recogieron 500 mL de agua de cada TBC tratado y fueron enviados al laboratorio para los bioensayos (exposición de 25 larvas durante 24 a 48 horas y registro de mortalidad. Resultados: Todos los TBC estuvieron infestados (mediana de 43,5 larvas. La mortalidad en los TBC a 24 horas fue 99,7% y no se evidenció recolonización de los TBC hasta la 14.ª semana. Sin embargo, en el laboratorio se evidencia disminución semanal de 11% de la mortalidad desde la 7.ª semana. La mortalidad en la semana número 14 estuvo asociada de forma inversa con la frecuencia de recambio de agua en los TBC (p<0,05. Conclusiones: No hubo evidencia en condiciones de campo de eficacia residual disminuida del temephos a la 14.a semana de aplicación. Este tipo de estudios deberían hacerse de manera rutinaria para vigilar la efectividad del larvicida temephos en Lima.

Competição intraespecífica em Boophilus microplus Intra-specific competition in Boophilus microplus

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Andreia Passos dos Santos

2002-12-01

Full Text Available O presente trabalho foi desenvolvido no Campo Experimental da Embrapa Gado de Leite, Coronel Pacheco, Minas Gerais, Brasil, tendo como objetivo a verificação da ocorrência de competição intra-específica durante a fase parasitária do carrapato bovino Boophilus microplus e a confirmação da correlação positiva entre o peso da fêmea ingurgitada e o peso da massa de ovos. Foram feitas observações em bovinos infestados naturalmente e experimentalmente, com cargas parasitárias e intervalos diferenciados. Os animais infestados permaneceram em baias individuais durante todo o período de queda das fêmeas ingurgitadas, para que estas pudessem ser coletadas diariamente. As diferenças observadas entre as médias de peso das fêmeas ingurgitadas, no decorrer dos dias de queda, sugeriram a ocorrência de competição durante a fase de alimentação. Observou-se também que o potencial de oviposição está diretamente relacionado a sua capacidade de alimentação.This study was developed in the Experimental Station of Embrapa Dairy Cattle, Coronel Pacheco, Minas Gerais, Brazil, and had the aim of verifying the occurrence of intra-specific competition in the cattle tick Boophilus microplus during its parasite life and to confirm the relation between the weight of engorged females and the egg mass laid. Observations were done with cattle naturally and experimentally infested with different quantities of larvae during different intervals of time. The infested animals remained in individual stalls for the whole period of engorged females drop-off, in order to collect them daily. The observed differences among weight of engorged females during drop-off days suggested the competition occurrence during the feeding phase. It was also seen that the oviposition potential of an engorged female is directly related to its feeding capacity.

Increased prevalence of Plasmodium falciparum malaria in Honduras, Central America Aumento de la prevalencia de malaria por Plasmodium falciparum en Honduras, Centroamerica

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Carol J. Palmer

1998-07-01

Full Text Available We report on our investigation of a malaria outbreak in Honduras, Central America, in January 1997. We tested 202 patients with fever and chills using thin and thick blood film microscopy. Sixteen patients lived in the city and the rest lived in rural areas. A total of 95 samples (47% were positive for malaria parasites. Seventy-nine percent (63/80 of the rural patients were infected with Plasmodium vivax and 21% (17/80 were infected with P. falciparum. In the urban area, all 15 infected patients had P. vivax malaria and none showed evidence of P. falciparum. Since previous reports indicate that falciparum malaria accounts for only 2% of the overall malaria infections in Honduras, the results reported here suggest that there is a dramatic increase in falciparum malaria in the area of Honduras investigated in this study.Notificamos los resultados de un estudio de un brote de malaria que se produjo en Honduras, Centroamérica, en enero de 1997. Sometimos a examen microscópico frotis delgados y frotis gruesos de la sangre de 202 pacientes con fiebre y escalofríos. Dieciséis pacientes eran habitantes de la zona urbana y el resto de la zona rural. Un total de 95 especímenes (47% fueron positivos a parásitos de la malaria. Setenta y ocho por ciento (62/80 de los pacientes del área rural estaban infestados con Plasmodium vivax y 22% (17/80 con P. falciparum. En la zona urbana, todos los 15 pacientes que estaban infestados tenían P. vivax y en ninguno se detectó P. falciparum. Ya que según informes previos la malaria de tipo falciparum representa solamente 2% de todos los casos de malaria en Honduras, nuestros resultados sugieren que hay un gran incremento del número de casos de malaria falciparum en la zona de Honduras en que se llevó a cabo esta investigación.

Efeito de vespas não-polinizadoras sobre o mutualismo Ficus - vespas de figos Effect of non-pollinating fig wasps over fig-fig wasp mutualism

Directory of Open Access Journals (Sweden)

Larissa G. Elias

Full Text Available Relações ecológicas interespecíficas, que resultam em benefício para todos os organismos participantes, são conhecidas como mutualismo. No entanto, tal cooperação abre espaço para o surgimento de estratégias oportunistas (ou de trapaça, representadas por indivíduos parasitas do mutualismo, que recebem o benefício de um dos parceiros sem oferecer nada em troca. A interação figueiras - vespas - de - figo é um sistema adequado para o estudo do mutualismo e de estratégias oportunistas (parasitas de mutualismos. Representantes do gênero Ficus (Moraceae apresentam uma relação mutualística com pequenas vespas polinizadoras (Agaonidae e são explorados por outras espécies de vespas não-polinizadoras. Esse trabalho teve como objetivo avaliar o impacto das vespas não-polinizadoras sobre o mutualismo Ficus citrifolia e suas vespas polinizadoras, Pegoscapus tonduzi Grandi, 1919. Para tal, foi comparada a produção de aquênios (função feminina e de fêmeas da espécie polinizadora (função masculina entre amostras de sicônios altamente infestados e pouco infestados por vespas não-polinizadoras, coletadas nos municípios de Londrina (Paraná, Campinas e Ribeirão Preto (São Paulo, Brasil. Nossos resultados apontaram que as vespas não-polinizadoras exercem impacto negativo nos componentes feminino e masculino da planta, sendo maior no masculino. A produção de vespas polinizadoras foi cerca de sete vezes menor nos figos infestados, ao passo que a produção de aquênios foi 1,5 vez menor nesses mesmos figos. Hipóteses sobre a estabilidade do mutualismo na presença das espécies oportunistas são discutidas.Mutualism is the name given to interspecific interactions which result in benefit for all partners involved. However, such cooperation is open to opportunistic strategies: individuals that extract the benefit from the partner, but do not offer any benefit in exchange. The fig-fig wasp interaction is an appropriate case to

Occurrence of Pasteuria spp. in the northeastern Spain

OpenAIRE

Verdejo Lucas, Soledad; Español Pons, Montserrat; Ornat Longarón, Cèsar; Sorribas Royo, Francisco Javier

1997-01-01

The occurrence of Pasteuria spp. In Spanish oils is reported. A total of 160 soil samples were collected from vegetable crops, kiwi and citrus orchards, and deciduous fruit trees. Bacteria were found associated with six nematode genera but they were only observed within females of Meloidogyne spp., second-stage juveniles and males of Tylenchulus semipenetrans, and juveniles of Pratylenchus spp.

Root-knot nematodes in golf course greens of the western United States

Science.gov (United States)

A survey of 238 golf courses in ten of the Western U.S. found root-knot nematodes (Meloidogyne spp.) in 60 % of the putting greens sampled. Sequence and phylogenetic analyses of 18S rRNA, D2-D3 of 28S rRNA, ITS-rRNA and mtDNA gene sequences were used to identify specimens from 110 golf courses. The...

Terra Incognita: Explanation and Reductionism in Earth Science

NARCIS (Netherlands)

Kleinhans, M.G.

2005-01-01

The present paper presents a philosophical analysis of earth science, a discipline that has received relatively little attention from philosophers of science. We focus on the question of whether earth science can be reduced to allegedly more fundamental sciences, such as chemistry or physics. In

Dicty_cDB: Contig-U16439-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available cDNA clon... 50 6e-16 3 ( FK739797 ) av01001d15r1.1 Symbiotic sea anemone (Anemonia vi... 84 4e-15 2 ( D872... ( CB933531 ) ri31b11.y1 Meloidogyne chitwoodi egg pAMP1 v1 Mel... 64 4e-11 2 ( FK729638 ) av02130e15r1.1 Symbiotic

Bromuro de metilo como tratamiento cuarentenario para cítricos infestados por la mosca del Mediterráneo

OpenAIRE

Zapater, Miguel Carlos

1992-01-01

p.171-176 Distintas variedades de naranjas, mandarinas y pomelos Infestadas por la mosca del Mediterráneo, Ceratitis capitata, fueron expuestas al bromuro de metilo (BM) para determinar la posibilidad de su empleo como tratamiento cuarentenario interno. 32 g-m3 de BM a 26 °C aplicados durante 2 hs. a fruta infestada artificialmente, alcanzaron el nivel de mortalidad correspondiente al standard probit 9, indicando su aptitud como fumigante adecuado para el tratamiento de las variedades cítr...

The Lives of Other Citizens

OpenAIRE

Irving, Andrew

2017-01-01

The capacity for a complex inner lifeworld that encompasses ongoing streams of inner dialogue and reverie, as well as non-linguistic or image based forms of thought, is an essential component of being human and central to many everyday actions and practices. Simply put, without inner expression there would be no self-understanding or social existence in any recognisable form. Despite this, it is largely a terra incognita for anthropology or is seen as irrelevant or intangible, rather than an ...

Aspectos clínico-epidemiológicos sobre pediculosis capitis en arenales, Estado Falcón, Venezuela Clinical and epidemiological aspects on pediculosis capitis in, Falcon State, Venezuela

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D Cazorla PerfettI

2012-03-01

Full Text Available la pediculosis capitis humana es una infestación del cuero cabelludo y del pelo, ocasionada por el Pediculus humanus capitis, la que puede producir infecciones bacterianas secundarias en el sitio del rascado, anemia y estrés social y psicológico con alteración en la calidad de vida y consternación. Entre Marzo y Julio de 2011, se realizó un trabajo para estudiar aspectos epidemiológicos y clínicos de la pediculosis capitis en 199 personas (79 varones y 120 mujeres, habitantes de diferentes grupos etéreos (0-75 años; ± D.S= 21,28 ± 17 de la población rural Arenales, zona semiárida del estado Falcón, región nor-occidental de Venezuela. El diagnóstico ectoparasitológico se realizó por observación directa con peine "ad hoc" de huevos (liendres, estados imaginales y/o pre-imaginales sobre el cuero cabelludo. Los insectos se clarificaron y montaron en medio de Hoyer para observación microscópica. Los resultados revelaron una prevalencia global de pediculosis capitis del 10,10% (20/199, con porcentajes de infestación significativamente mayores en las niñas (90 vs 10% [Odds Ratio (OR = 3,04; p = 0,01] en edad escolar (OR= 1,02; p =0,015; con longitudes de cabello mayores de 3 cm (OR = 2,44; p = 0,004 y de tipo lisotrico (OR = 2,25; p = 0,015, sin embargo, no fueron diferentes entre grupos étnicos y color de pelo (P > 0,05. Se detectó un predominio de liendres (65% desde 1 hasta 64/individuos, ubicadas entre 0,1 y 9 cm del cuero cabelludo en todas las regiones de la cabeza, teniendo los individuos de menor edad las mayores cargas ectoparasitarias. Los síntomas significativamente asociados a pediculosis fueron el prurito (6,53% en individuos infestados y 12,06% en los no infestados; OR =11,99; p = 0,000 y las excoriaciones (1,51% en niños infestados y 3,52% en los no infestados; OR =4,34; p = 0,03. Otros posibles factores de riesgo significativamente involucrados en la dinámica de transmisión y mantenimiento de la infestaci

Meloidogyne ulmi: een nieuwe iepenparasiet in Nederland?

NARCIS (Netherlands)

Karssen, G.; Keulen, van I.; Hoenselaar, van T.; Heese, van E.

2008-01-01

eloidogyne ulmi In de land- en tuinbouw zijn plant-parasitaire nematoden een bekend fenomeen: in meer of mindere mate parasiteren deze draadwormen op vrijwel alle gewassen. Schade varieert van groeireductie tot complete misoogsten. Wereldwijd behoort de groep van de wortelknobbelnematoden, ofwel

Ecología del Aedes aegypti en un pueblo de Colombia, Suramérica

Directory of Open Access Journals (Sweden)

Milton E. Tinker

1993-03-01

Full Text Available Un estudio de la ecología de las larvas y adultos del Aedes aegypti fue llevado a cabo en Guaduas (Cundinamarca entre noviembre de 1978 y noviembre de 1979. Este estudio comprendió cuatro ciclos de inspección, dos en época seca y dos en época lluviosa. Las albercas fueron encontradas como el mejor hábitat larvario para ambas estaciones. Las llantas fueron igualmente importantes en la época de lluvia. Las alcobas constituyeron el hábitat más favorable para los adultos. En general más predios estaban infestados por adultos que por larvas. La prueba de las precipitinas indicó que la mayoría de las hembras de Aedes aegypti se alimentaron sobre el hombre. Las colecciones con cebo humano demostraron 2 picos de actividad: 10 -1 1 a.m. y 4-5 p.m.

Triatoma infestans colonizando em domicílios da Baixada Fluminense, Estado do Rio de Janeiro, Brasil

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Mário B. Aragão

1971-06-01

Full Text Available Nos municípios de Duque de Caxias e Nova Iguaçu, que fazem parte do Grande Rio de Janeiro, foram encontrados domicílios infestados pelo T. infestans. Em duas locdades do Município de Duque de Caxias (Amapá e Piranema foram encontrados T. infestans infectados por flagelados morfologicamente indistinguíveis do Trypanosoma cruzi, sendo de notar que alguns dêsses insetos foram coletados em uma casa em que os moradores nunca tinham estado em zona afetada pela doença de Chagas. Os autores concluam que a infestação deve ser recente e discutem o problema dêsse triatomíneo estar proliferando num clima opôsto ao de sua área de dispersão e numa região onde os triatomíneos silvestres, que penetram nos domicílios, não conseguem formar colônias.

Multiple-strand displacement and identification of single nucleotide polymorphisms as markers of genotypic variation of Pasteuria penetrans biotypes infecting root-knot nematodes.

Science.gov (United States)

Nong, Guang; Chow, Virginia; Schmidt, Liesbeth M; Dickson, Don W; Preston, James F

2007-08-01

Pasteuria species are endospore-forming obligate bacterial parasites of soil-inhabiting nematodes and water-inhabiting cladocerans, e.g. water fleas, and are closely related to Bacillus spp. by 16S rRNA gene sequence. As naturally occurring bacteria, biotypes of Pasteuria penetrans are attractive candidates for the biocontrol of various Meloidogyne spp. (root-knot nematodes). Failure to culture these bacteria outside their hosts has prevented isolation of genomic DNA in quantities sufficient for identification of genes associated with host recognition and virulence. We have applied multiple-strand displacement amplification (MDA) to generate DNA for comparative genomics of biotypes exhibiting different host preferences. Using the genome of Bacillus subtilis as a paradigm, MDA allowed quantitative detection and sequencing of 12 marker genes from 2000 cells. Meloidogyne spp. infected with P. penetrans P20 or B4 contained single nucleotide polymorphisms (SNPs) in the spoIIAB gene that did not change the amino acid sequence, or that substituted amino acids with similar chemical properties. Individual nematodes infected with P. penetrans P20 or B4 contained SNPs in the spoIIAB gene sequenced in MDA-generated products. Detection of SNPs in the spoIIAB gene in a nematode indicates infection by more than one genotype, supporting the need to sequence genomes of Pasteuria spp. derived from single spore isolates.

Studies on Meloidogyne javanica infestation on roma tomato ...

African Journals Online (AJOL)

USER

2010-05-31

May 31, 2010 ... 1Department of Crop Production, Federal College of Agriculture, Ishiagu, Nigeria. 2Department of ... using pot experiment. ... and Rice husk ash) at the range of 10 to 20 t/ha were good for optimum growth, performance and.

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

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Mario Fajardo P

2011-06-01

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

Study the Effect of Three Species of Medicinal Plants of the Mint Family on Pathogenicity and Damage Root Knot Nematode Meloidogyne javanica in Tomato

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Maryam Fayaz

2017-03-01

Full Text Available Introduction: Root-knot nematodes (Meloidogyne spp. are important plant pathogens that make large damage to the crops. The activity of root-knot nematode and reaction of host plant results in the development of several knots on the root, which interrupts water and food absorption system of the plant. Among popular methods for controlling root-knot nematodes are physical methods (soil solarization and flooding, farming methods (crop rotation, weed removal, contaminated roots removal, fertilization, soil reinforcement, planting time adjustment, and use of resistant varieties, and chemical methods (disinfection with pesticide and foliar spray. Incomplete control, high cost and environmental problems (chemical compounds have directed some researchers toward to use non-chemical methods such as herbs and herbal products for the management nematodes. Mankind has used medicinal plants throughout the history in both direct and indirect ways. Today, medicinal plants have a considerable share of medical products. The nematicidal effect of many plants has been demonstrated and the use of plant products has been considered as a safe method to control root-knot nematode. This method is cheap and easy to use, does not cause environmental pollution, and is able to improve the soil in structural and nutritional terms. Organic plants possess a wide range of secondary metabolites such as phenyls, flavonoids, coinons, tanons, essences, alkaloids, saponins, and sterols. These substances are biodegradable owing to their natural origin and do not pollute the environment. Today, active plant compounds are given much attention because they are less durable and do not have the negative impact on mammals and non-target organisms. Plant products including essences and extracts are usually used to control plant diseases nematodes. Therefore, due to the favorable impact of plants in controlling Root-knot nematodes, In this study, the presence of several herbs (thyme, hyssop

Evaluation of allyl isothiocyanate as a soil fumigant against soil-borne diseases in commercial tomato (Lycopersicon esculentum Mill.) production in China.

Science.gov (United States)

Ren, Zongjie; Li, Yuan; Fang, Wensheng; Yan, Dongdong; Huang, Bin; Zhu, Jiahong; Wang, Xiaoning; Wang, Xianli; Wang, Qiuxia; Guo, Meixia; Cao, Aocheng

2018-03-12

Root-knot nematodes (Meloidogyne spp.), soil-borne diseases and weeds seriously reduce the commercial yield of tomatoes grown under protected cultivation in China. Allyl isothiocyanate (AITC), a natural product obtained from damaged Brassica tissues, was evaluated as a potential replacement for the fumigant methyl bromide (MB) for use in the greenhouse production of tomatoes in China. The dose-response assay indicates that AITC has high biological activity against major bacterial and fungal pathogens (EC 50 of 0.225-4.199 mg L -1 ). The bioassay results indicate that AITC has good efficacy against root-knot nematodes (LC 50 of 18.046 mg kg -1 ), and moderate efficacy against fungal pathogens (LC 50 of 27.999-29.497 mg kg -1 ) and weeds (LC 50 of 17.300-47.660 mg kg -1 ). The potting test indicates that AITC significantly improved plant vigor. Field trials indicate that AITC showed good efficacy against Meloidogyne spp. and Fusarium spp. (both ∼ 80%) as well as Phytophthora spp. and Pythium spp. (both ∼ 70%), and improved plant vigor and marketable yield. AITC used as a soil fumigant (30-50 g m -2 ) effectively controlled major bacterial and fungal pathogens, root-knot nematode, weeds and increased plant vigor, yield and farmers' income in tomato cultivated under protected agriculture in China. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

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

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W. H. Gera eHol

2016-02-01

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

La ruta de señalización del acido salicílico juega un papel importante en la resistencia en tomate a Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) mediada por el gen Mi-1

OpenAIRE

Muñiz, Mariano; Rodriguez, C.I.; Kaloshian, I.; Nombela, Gloria

2009-01-01

Es bien conocido que la resistencia en tomate a Bemisia tabaci (Gennadius), a Macrosiphum euphorbiae (Thomas) y a tres especies de nematodos formadores de nódulos (Meloidogyne spp.) está mediada por el gen Mi-1. Asimismo, está documentado que el ácido salicílico interviene en los mecanismos de resistencia frente a nematodos formadores de nódulos y áfidos. Recientemente se ha descrito que, en Arabidopsis, el biotipo B de B. tabaci induce defensas activadas por este ácido e inhibe las del ácido...

Methyl transfer in glucosinolate biosynthesis mediated by indole glucosinolate O-Methyltransferase 5

DEFF Research Database (Denmark)

Pfalz, Marina; Mukhaimar, Maisara; Perreau, François

2016-01-01

in position 1 (1-IG modification) or 4 (4-IG modification). Products of the 4-IG modification pathway mediate plant-enemy interactions and are particularly important for Arabidopsis innate immunity. While CYP81Fs encoding cytochrome P450 monooxygenases and IGMTs encoding indole glucosinolate O...... with moderate similarity to previously characterized IGMTs, encodes the methyltransferase that is responsible for the conversion of 1OHI3M to 1MOI3M. Disruption of IGMT5 function increases resistance against the root-knot nematode Meloidogyne javanica and suggests a potential role for the 1-IG modification...

Prevalencia de Sarcocystis sp. en vacunos, ovinos y caprinos beneficiados en los camales de Lima

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Julia Castro

2014-06-01

Full Text Available Se ha realizado el presente estudio para determinar la prevalencia de Sarcocystis sp. en vacunos, ovinos y caprinos utilizando el método del tríquinoscopio con muestras de tejido cardíaco y esófago. Los resultados mostraron que de 85 muestras de tejido cardíaco de ganado vacuno, 76 fueron positivas (89.5%; de 134 muestras de ganado ovino 122 fueron positivas (91.04% mientras que de 63 muestras de ganado capriino solo en 33 (52.4% se encontró la presencia del parásito. En cuanto a las muestras de esófago los porcentajes de parasitismo fueron los siguientes: 2% para el vacuno; 39.8% para el ovino y 76.2% para el caprino. Estos valores indicaron que el mayor parasitismo en vacunos y ovinos está localizado en el corazón, mientras que en caprinos el órgano más infestado es el esófago. Por lo tanto existe un elevado parasitismo por Sarcocystis sp. en el ganado beneficiado para consumo humano.

Estrategia de Ascaris lumbricoides y Trichuris trichiura para la contaminación del medio ambiente, en una zona endemica Strategy of Ascaris lumbricoides and Trichuris trichiura for the environment contamination in an endemic area

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Gustavo Morales

1988-06-01

Full Text Available La distribución de frecuencias del número de huevos por gramo de heces tanto de Ascaris lumbricoides como de Trichuris trichiura en humanos infestados en una zona endémica se corresponde con una ley binomial negativa y la disposición espacial de dichos huevos en la materia fecal, resultó ser en agregados, independientemente de que los hospedadores sean mayores o menores de 15 años. Estos resultados nos indican que solamente unos pocos hospedadores son los responsables de la mayor contaminación del medio ambiente y que esos individuos no pertenecen a ningún grupo etario en particular.The distribution of frequences of the number per grame of Ascaris lumbricoides and Trichuris trichiura in the faeces of naturally infected human in endemic areas, were found following a negative binomial distribution and an overdispersal pattern, independently of the ages of hosts. These results show, that only few hosts, independently of their ages, are involved in the higher environment contamination.

Estudios sobre Trypanosomiasis americana en el Perú. Observaciones en el departamento de Ica

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Víctor M Ayulo Robles

1946-01-01

Full Text Available Hemos comprobado la presencia de Triatomas en las ciudades de Ica y Nazca. Los Triatomas encontrados en esas localidades son de la especie del Triatoma Infestans. Las observaciones del contenido intestinal de los Triatomas capturados en ambas ciudades reveló que ellos no se encuentran infestados; lo que hace sospechar que estos insectos procedan de la Ciudad de Arequipa. Los exámenes de sangre en fresco, gota gruesa y frotis coloreados por el método de Giemsa en 174 personas y 32 animales, así como las pruebas de Desviación del Complemento (Reacción de GUERREIRO Y MACHADO e intradermo-reacción en las 174 personas, fueron negativas; lo que demuestra que actualmente no existe la Enfermedad de Chagas en el Departamento de Ica. Dada la presencia de Triatomas en Ica y Nazca y la existencia de la Enfermedad de Chagas en Vitor, Sihuas y Quishuarani del Departamento de Arequipa no se excluye la posibilidad de que posteriormente se haga presente la Trypanosomiasis americana, también, en esas zonas.

Interspecific nematode signals regulate dispersal behavior.

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Fatma Kaplan

Full Text Available Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2 of plant parasitic Meloidogyne spp. and infective juveniles (IJs of entomopathogenic nematodes (EPN, e.g., Steinernema feltiae. Regulation of dispersal behavior has not been thoroughly investigated for C. elegans or any other nematode species. Based on the fact that ascarosides regulate entry in dauer stage as well as multiple behaviors in C. elegans adults including mating, avoidance and aggregation, we hypothesized that ascarosides might also be involved in regulation of dispersal behavior in C. elegans and for other nematodes such as IJ of phylogenetically related EPNs.Liquid chromatography-mass spectrometry analysis of C. elegans dauer conditioned media, which shows strong dispersing activity, revealed four known ascarosides (ascr#2, ascr#3, ascr#8, icas#9. A synthetic blend of these ascarosides at physiologically relevant concentrations dispersed C. elegans dauer in the presence of food and also caused dispersion of IJs of S. feltiae and J2s of plant parasitic Meloidogyne spp. Assay guided fractionation revealed structural analogs as major active components of the S. feltiae (ascr#9 and C. elegans (ascr#2 dispersal blends. Further analysis revealed ascr#9 in all Steinernema spp. and Heterorhabditis spp. infected insect host cadavers.Ascaroside blends represent evolutionarily conserved, fundamentally important communication systems for nematodes from diverse habitats, and thus may provide sustainable means for control of parasitic nematodes.

COMPORTAMIENTO DE LÍNEAS AVANZADAS DE TOMATE ( Solanum lycopersicum L. A FITOPATÓGENOS EN CHAPINGO, MÉXICO

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Santos Gerardo Leyva-Mir

2013-01-01

Full Text Available Con el objetivo de evaluar la respuesta de 18 líneas experimentales y dos genotipos comerciales de tomate ( Solanum lycopersicum L. ante la infección natural de patógenos ( Alternaria solani, Phytophthora infestans, Fusarium oxysporum, Nacobbus spp . y Meloidogyne spp . de importancia económica, se realizó un ensayo en el campo agrícola experimental de la Universidad Autónoma Chapingo con el diseño experimental bloques completos al azar con cuatro repeticiones. Se evaluó el grado de severidad de cinco patógenos sobre las plantas de los genotipos considerados. Previo a la evaluación se identificó a cada patógeno en laboratorio por medio de la morfología de sus estructuras reproductivas. Se aplicó la prueba no paramétrica de Friedman a los datos obtenidos y posteriormente se realizó la comparación múltiple de rangos. Se detectaron fuentes de resistencia para Alternaria solani con severidad final del 35 %, en comparación con los genotipos susceptibles que fue del 80 %. En el caso de Phytopthora infestans la severidad final alcanzó 60 %, mientras que la susceptibilidad correspondió a 100 %. En el caso de Fusarium oxysporum se obtuvo un valor de 10 % de daño contra los susceptibles con 40 % . Con respecto a nematodos ( Nacobbus spp. y Meloidogyne spp., se determinó tolerancia con registros de 30 % de agallamiento y 76 % en líneas susceptibles.

Les problèmes phytosanitaires de la culture de tomate d'arrière-saison au Nebhana : résultats d'une enquête

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Moens, M.

1986-01-01

Full Text Available The phytosanitary problems of the post-season tomato crop in the Nebhana region (Tumsia results of a survey. The post-season tomato crop has been surveyed in the irrigated area of Teboulba in order to estimate the importance of the phytosanitary problems and to evaluate the control mesures practised by the farmers. The principal ennemies were : root-knot nematodes (Meloidogyne spp., fusarium wilt ('Fusarium oxysporum f. sp. lycopersici,, powdery mildew (Leveillula tauricaj, early blight (Alternaria solanij and a virus disease causing yellow leaf curl. The crop protection was revealed insufficient ; new control mesures are reviewed.

Características biológicas de Boophilus microplus (acari: ixodidae a partir de infestação experimental em cão Biological characteristics of Boophilus microplus (acari: ixodidae on dog under experimental infestation

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Marcos P. Franque

2007-12-01

Full Text Available Boophilus microplus (Canestrini, 1887, um parasita comum dos bovinos, tem sido observado em cães. Com objetivo de descrever características biológicas desse parasitismo, um cão foi infestado experimentalmente com 10.000 larvas de B. microplus previamente mantidas em câmara climatizada a 27 ± 1 ºC e umidade relativa superior a 80%. A média da fase parasitária foi de 24,4 ± 1,50 dias, com uma taxa de recuperação de 0,42%. Das 21 fêmeas desprendidas natural e precocemente do hospedeiro, 6 (28% ingurgitaram o suficiente (75,1 ± 30,23mg para realizar postura. O período médio de prépostura foi de 4,33 ± 1,37 dias e o período médio de postura de 9,17 ± 2,32 dias, com produção média de 18,78 ± 15,34mg de postura. O índice médio de produção de ovos observado foi de 22,38%. Estes resultados demonstraram que fêmeas de B. microplus alimentadas em cão experimentalmente infestado, completam seu ciclo biológico. A obtenção de fêmeas, capazes de realizar posturas viáveis, sugerem a possibilidade do cão atuar como hospedeiro alternativo para B. microplus, especialmente quando não há disponível outra espécie de hospedeiro preferencial.Boophilus microplus, a common parasite of cattle, has eventually reported in dogs. To describe biological features of this parasitism, one dog was experimentally infested with 10,000 larvae of B. microplus which were previously held in acclimatized camera at 27 ±1ºC and relative humidity up to 80%. The mean of parasitic phase was 24.4 ± 1.50 days, with 0.42% of recovery rate. Of 21 natural detached B. microplus females, six engorged enough (75.1 ± 30.23mg to achieve posture. The mean period of pre-posture was 4.33 ± 1.37 days and the means period of posture was 9.17 ± 2.32, producing a mean of 18.78 ± 15.34 posture weight. The mean of eggs production index observed was 22.38%. The results showed that B. microplus females fed on dogs to complete their life cycle. The females collected

Ticks on domestic animals in Pernambuco, Northeastern Brazil Carrapatos em animais domésticos em Pernambuco, Nordeste do Brasil

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Filipe Dantas-Torres

2009-09-01

Full Text Available The objective of this article was to discuss some aspects of ticks associated with domestic animals in the State of Pernambuco, northeastern Brazil, based on a literature review and present new data obtained from recent tick collections carried out in this northeastern Brazilian state. From August 2007 to June 2008, 1,405 ticks were collected and five species were identified: Amblyomma cajennense (Fabricius, 1787, Amblyomma ovale Koch, 1844, Dermacentornitens Neumann, 1897, Rhipicephalus (Boophilus microplus (Canestrini, 1887, and Rhipicephalus sanguineus (Latreille,1806. Dogs from urban areas were found exclusively infested by R. sanguineus, whereas dogs from rural areas were found infested by A. cajennense, A. ovale, R. (B. microplus, and R. sanguineus. The only tick species found on cattle and goats was R. (B. microplus. Horses were found infested by D. nitens and at a lesser extent by A. cajennense and R. (B. microplus. The only tick species found on donkeys was D. nitens. This study confirms the presence of A. cajennense inPernambuco and describes for the first time the presence of A. ovale in this state. The medical and veterinary relevance and control of ticks associated with domestic animals in Pernambuco are also briefly discussed.O objetivo desse artigo é discutir alguns aspectos relacionados aos carrapatos que parasitam animais domésticos no Estado de Pernambuco com base numa revisão da literatura e apresentar novos dados obtidos a partir de recentes coletas de carrapatos realizadas nesse estado do nordeste brasileiro. De agosto de 2007 a junho de 2008, 1.405 carrapatos foram coletados e cinco espécies foram identificadas: Amblyomma cajennense (Fabricius, 1787, Amblyomma ovale Koch, 1844, Dermacentor nitens Neumann, 1897, Rhipicephalus (Boophilus microplus (Canestrini, 1887 e Rhipicephalus sanguineus (Latreille, 1806. Cães de áreas urbanas foram encontrados infestados exclusivamente por R. sanguineus ao passo que cães de �

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

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P. E. V. Aguiar

2014-09-01

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

Conscience and consciousness: a definition.

Science.gov (United States)

Vithoulkas, G; Muresanu, D F

2014-03-15

While consciousness has been examined extensively in its different aspects, like in philosophy, psychiatry, neurophysiology, neuroplasticity, etc., conscience though it is an equal important aspect of the human existence, which remains an unknown to a great degree as an almost transcendental aspect of the human mind. It has not been examined as thoroughly as consciousness and largely remains a "terra incognita" for its neurophysiology, brain topography, etc. Conscience and consciousness are part of a system of information that governs our experience and decision making process. The intent of this paper is to define these terms, to discuss about consciousness from both neurological and quantum physics point of view, the relationship between the dynamics of consciousness and neuroplasticity and to highlight the relationship between conscience, stress and health.

Production of n-rich Nuclei along the Closed Shell N=126 in the collision 136Xe + 208Pb @E lab =870 MeV

Science.gov (United States)

Quero, D.; Vardaci, E.; Kozulin, E. M.; Zagrebaev, V. A.; Corradi, L.; Pulcini, A.; La Rana, G.; Itkis, I. M.; Knyazheva, G. N.; Novikov, K.; Harca, I.; Fioretto, E.; Stefanini, A. M.; Montanari, D.; Montagnoli, G.; Scarlassara, F.; Szilner, S.; Mijatović, T.; Trzaska, W. H.

2018-05-01

Multi-nucleon transfer reactions are nowadays the only known mean to produce neutron-rich nuclei in the Terra Incognita. The closed-shell region N=126 is crucial for both studying shell-quenching in exotic nuclei and the r-process, being its last “waiting-point”. The choice of suitable reactions is challenging and a favorable case is 136Xe+208Pb, near the Coulomb barrier, because their neutron shell-closures play a stabilizing role, favoring the proton-transfer from lead to xenon. TOF-TOF data were analyzed to reconstruct the mass-energy distribution of the primary fragments. Preliminary results of an experiment held at Laboratori Nazionali di Legnaro with PRISMA, aimed at A and Z identification of the products, will be shown.

Parasitismo de Meloidogyne enterolobii em espécies de myrtaceae

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Luiza Suely Semen Martins

2013-06-01

Full Text Available A meloidoginose da goiabeira, causada por M. enterolobii (= M. mayaguensis, é hoje considerado o principal problema fitossanitário desta cultura em todo o País, pois sua incidência resulta em acentuada queda de produtividade e, na maioria das vezes, a morte das plantas em médio prazo. Visando a seu controle, objetivou-se neste trabalho identificar fontes de resistência em goiabeira Psidium guajava L e araçazeiro Psidium sp.. Foram avaliados onze genótipos oriundos do Câmpus da Universidade Federal de Lavras (UFLA e de regiões próximas ao município de Lavras (MG. As sementes foram coletadas de frutos fisiologicamente maduros e germinadas em piscinas hidropônicas. Ao atingirem 12 cm de altura, foram transferidas para casa de vegetação, em vasos individuais, e mantidas a temperatura entre 18-38°C. Após quinze dias, foram inoculados individualmente com suspensão de 10.000 ovos e juvenis de segundo estádio (J2 de M. enterolobii e avaliadas após 120 dias. As reações dos hospedeiros foram enquadradas nos parâmetros estabelecidos pelo fator de reprodução FR, estimado pelo quociente Pf/Pi, em que Pf representa a população final e Pi a população inicial. O delineamento utilizado foi o inteiramente casualizado, com 11 genótipos, uma espécie de nematoide e seis repetições, sendo duas plantas em cada genótipo adicionadas como controle. Quatro meses depois, foram avaliados os teores foliares de macro e micronutrientes e o grau de infecção de cada genótipo. A produção média de ovos e J2 de M. enterolobii variou de 200 a 428.146,1, e os fatores de reprodução (FR médios variaram de 0,02(ALU1 a 42,81(A-PASTO. Os genótipos de araçazeiro (Psidium spp. AUFLA1, AUFLA4, AUFLA5 e APASTO e os genótipos de goiabeira (P. guajava G-ROXA e G-AMAR foram considerados suscetíveis. Os genótipos de araçazeiro ALU1, ALU2, ALU3, AROXO-C e AROXO-U mostraram-se resistentes, reforçando a necessidade de trabalhos complementares com essas espécies para uso como porta-enxerto em cultivares comerciais de goiabeira. A absorção de macro e micronutrientes é alterada quando os genótipos de Psidium spp. são inoculados com o fitonematoide M. enterolobii.

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

International Nuclear Information System (INIS)

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

1989-01-01

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

Estudo sobre triatomíneos e reservatórios silvestres de Trypanosoma cruzi no estado do Paraná, Sul do Brasil. Resultados preliminares

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Toledo Max Jean de Ornelas

1997-01-01

Full Text Available Em localidades da zona rural de cinco municípios da região noroeste do Paraná adultos e ninfas de Triatoma sordida foram capturados em 21 (41,2% de 51 unidades domiciliares pesquisadas. Foram capturados 154 exemplares de T. sordida e 2 Panstrongylus megistus. De 135 exemplares examinados 58 (43,0% apresentavam o Trypanosoma tipo cruzi. Constatou-se também a infecção em 57,1% (4/7 dos gambás (Didelphis sp examinados. O peridomicílio apresentou-se mais infestado que o intradomicílio, sendo a casa de madeira abandonada a construção mais freqüente (34,7% do total investigado e com maior taxa de infestação (53,9%. Os dados mostram um elevado índice de infestação da zona rural por espécies secundárias de triatomíneos com altas taxas de infecção por flagelados do tipo T. cruzi, em uma área endêmica para a doença de Chagas já em fase de vigilância epidemiológica.

Implantação de colônia de Ctenocephalides felis felis (Bouché, 1835 e determinação do período de desenvolvimento dos estágios imaturos sob condições controladas / Implantation of a Ctenocephalides felis felis (Bouché, 1835 colony and determination of the development period of the immature stages under controlled conditions

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Karina Carrão Castagnolli

2008-09-01

Full Text Available O presente estudo teve como objetivo a implantação de uma colônia de pulgas (Ctenocephalides felis felis, para determinação do período de desenvolvimento dos estágios imaturos desse inseto, quando mantido emcondições controladas. Para isto, gatos foram infestados artifi cialmente com estágios adultos de C. felis felis e mantidos em gaiolas metálicas suspensas. Diariamente, durante trinta dias, os ovos de pulgas provenientes dos gatos eram recolhidos e mantidos em estufa do tipo B.O.D., com Tode 28±1oC e umidade relativa de 75%. O tempo de eclosão larval foi em média de dois a quatro dias, as pré-pupas surgiram no período de seis a nove dias, a pupação iniciou-se com nove a onze dias e a emergência dos adultos variou de quatorze a vinte dias. Nessas condições climáticas associadas à dieta adotada, foi possível uma recuperação de adultos de aproximadamente 90%, resultados favoráveis à manutenção de umacolônia.

Infestacion domestica por triatoma infestans y prevalencia de seropositivos al Trypanosoma cruzi en un area rural del nordeste argentino

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M. Esther Bar

1996-12-01

Full Text Available Se llevó a cabo un estúdio epidemiológicopara obtener unpanorama general de la transmisión doméstica del Trypanosoma cruzi en áreas rurales del Departamento San Miguel, Conientes, Argentina. Se investigaron 100 viviendas precarias, 50,0% de las mismas resultó infestado por Triatoma infestans y 1,0% por T. sórdida, citãndose por primera vez para la provinda de Comentes la colonización domiciliaria de esta especie. El 23,1% de T. infestans estaba infectado por T. cruzi. La seroprevalencia de 388 pacientes analizados por hemaglutinacíôn indirecta e inmunofluorescencia indirecta fue 23,4%, destacándose el alto índice (12,9% constatado en menores de 10 anos. Losporcentajes de seropositividad aumentaron con la edad, alcanzándose 50,0% de infectados entre los 31-40 anos. La infestación doméstica por T. infestans, la prevalencia humana de seropositivos al T. cruzi y las condiciones deprecariedad en que se desenvuelve la vida de los pobladores revelan la vigência de la endemia chagãsica en el área estudiada.

A perspective on terra incognita: uncovering the neuroanatomy of the human subcortex

NARCIS (Netherlands)

Alkemade, A.; Keuken, M.C.; Forstmann, B.U.

2013-01-01

Recent exciting advancements in the field of in vivo neuroimaging allow for visualization of the living human brain with unprecedented anatomical detail. Large consortium studies will provide us with novel insights in the function and connectivity of the human brain. However, it is unlikely that the

Irradiation as a quarantine treatment of cut flowers, ginger and turmeric against mites, thrips and nematodes

International Nuclear Information System (INIS)

Bhuiya, A.D.; Majumder, M.Z.R.; Hahar, G.; Shahjahan, R.M.; Khan, M.

1999-01-01

Effect of radiation on different developmental stages of mites, thrips, and nematodes were observed to determine their sterility doses and to develop a method for detection of irradiated and unirradiated specimens. A brief survey on cut-flower and tuber associated pests, and their biological study along with the tolerance level of host products were conducted. Mites Oligonychus biharensis (Hirst) and Tetranychus sp., as well as four species of thrips viz. Retithrips syriacus (Mayet), Haplothrips gowdeyi Franklin, Frankliniella intonsa Tribom, and Microcephalothrips abdominalis Crowford were recognized as common pests damaging plants and cut-flowers. Common species of nematodes infesting ginger and turmeric were Meloidogyne spp. and Ditylenchus spp. Results indicated that a dose 0.2 kGy and above caused complete sterility of male and female mites and insects. Various pre-adult developmental stages required less irradiation dose (0.05-0.1 kGy) for sterilization. Variation of melanization in treated and untreated life stages of mites and thrips could not be observed even at 0.2 kGy with the 2-methyl DOPA spot test. Inhibition of melanization in irradiated pupal stages of thrips were observed at doses above 0.4 kGy. Both irradiated and unirradiated thrips were identical in their protein banding pattern. Virtually no protein bands were observed in irradiated and unirradiated nematodes when samples were run on 5% PAGE in TBE. Tube rose and marigold treated with higher dose (0.3 to 0.5 kGy) caused no remarkable morphological degradation for 7-8 days after irradiation. Nematodes were resistant to radiation. Complete elimination and abnormalities of J 2 stages of Meloidogyne spp. and Ditylenchus spp. were not observed even at 4.0 kGy although significant weight loss and spoilage of tubers were recorded after 14 days of radiation exposure. (author)

QTL mapping and transcriptome analysis of cowpea reveals candidate genes for root-knot nematode resistance.

Science.gov (United States)

Santos, Jansen Rodrigo Pereira; Ndeve, Arsenio Daniel; Huynh, Bao-Lam; Matthews, William Charles; Roberts, Philip Alan

2018-01-01

Cowpea is one of the most important food and forage legumes in drier regions of the tropics and subtropics. However, cowpea yield worldwide is markedly below the known potential due to abiotic and biotic stresses, including parasitism by root-knot nematodes (Meloidogyne spp., RKN). Two resistance genes with dominant effect, Rk and Rk2, have been reported to provide resistance against RKN in cowpea. Despite their description and use in breeding for resistance to RKN and particularly genetic mapping of the Rk locus, the exact genes conferring resistance to RKN remain unknown. In the present work, QTL mapping using recombinant inbred line (RIL) population 524B x IT84S-2049 segregating for a newly mapped locus and analysis of the transcriptome changes in two cowpea near-isogenic lines (NIL) were used to identify candidate genes for Rk and the newly mapped locus. A major QTL, designated QRk-vu9.1, associated with resistance to Meloidogyne javanica reproduction, was detected and mapped on linkage group LG9 at position 13.37 cM using egg production data. Transcriptome analysis on resistant and susceptible NILs 3 and 9 days after inoculation revealed up-regulation of 109 and 98 genes and down-regulation of 110 and 89 genes, respectively, out of 19,922 unique genes mapped to the common bean reference genome. Among the differentially expressed genes, four and nine genes were found within the QRk-vu9.1 and QRk-vu11.1 QTL intervals, respectively. Six of these genes belong to the TIR-NBS-LRR family of resistance genes and three were upregulated at one or more time-points. Quantitative RT-PCR validated gene expression to be positively correlated with RNA-seq expression pattern for eight genes. Future functional analysis of these cowpea genes will enhance our understanding of Rk-mediated resistance and identify the specific gene responsible for the resistance.

Penyakit-Penyakit Penting Buah Naga di Tiga Sentra Pertanaman di Jawa Tengah

Directory of Open Access Journals (Sweden)

Arif Wibowo

2011-12-01

Full Text Available The objective of this study was to identify the causal agent of some dragon fruit disease emerging in Daerah Istimewa Yogyakarta (DIY and Central Java. Samples were taken from the dragon fruit plantation from the district of Sleman and Kulonprogo, Province of Daerah Istimewa Yogyakarta as well as Magelang, Province of Central Java. Isolation of pathogen from symptomatic plant tissue was performed on Potato Dextrose Agar (PDA for fungi and Nutrient Agar (NA for bacteria and continued with Koch's postulates testing. The results of field observation showed that the disease commonly occured in all 3 plantations of dragon fruit were stem rot caused by Erwinia sp. and scab caused by Pestalotiopsis sp. Other miscellaneous diseases found among the plantations were brown spot (Fusarium sp., anthracnose (Colletotrichum sp., mosaic that might be caused by Cactus Virus X, root knotnematode (Meloidogyne sp., black rot and red spot which were still unidentified. Penelitian ini bertujuan untuk mengetahui penyakit-penyait penting pada tanaman buah naga yang ditanam pada sentra pertanaman buah naga di Propinsi Daerah Istimewa Yogyakarta (DIY dan Jawa Tengah, serta untuk mengidentifikasi penyebab penyakit penting tersebut. Sampel tanaman buah naga diambil dari pertanaman buah naga di Kabupaten Sleman dan Kulon Progo untuk Provinsi DIY serta Magelang untuk Propinsi Jawa Tengah. Isolasi patogen dari jaringan tanaman bergejala dilakukan pada medium Potato Dextrose Agar (PDA untuk jamur dan Nutrient Agar (NA untuk bakteri serta dilanjutkan dengan uji Postulat Koch. Hasil pengamatan di lapangan menunjukkan bahwa penyakit yang umum terdapat di 3 lokasi pertanaman buah naga tersebut adalah busuk batang yang disebabkan oleh Erwinia sp. dan kudis yang disebabkan oleh Pestalotiopsis sp. Adapun penyakit-penyakit lain yang dijumpai antara lain bercak coklat (Fusarium sp., antraknosa (Colletotrichum sp., mosaik yang kemungkinan disebabkan oleh Cactus Virus X, puru akar

Le Roman d’Enéas: un cas de déclinaison de l’étranger sur la trajectoire de l’exil

Directory of Open Access Journals (Sweden)

Catherine Desprès Caubrière

2013-11-01

Full Text Available In the Roman d'Enéas the protagonist, after his Virgilian model, follows his mythical non-return path to exile, his journey being assumed as the beginning of the adventure as well as a sine qua non condition for the foundation. The repeated ordeals faced by the hero at each stage of his travel towards a new terra incognita provoke anguish, which constitutes the basis of his initiation while his charisma grows. The textual point of view on Enéas's existential experience from the perspective of the inclusion/exclusion ambivalence confirms his status as a forreigner, and means real conflict both social and psychological, but foremost represents a major theme contributing to the building of the fiction character and to the emerging definition of a new genre.