Made available in DSpace on 2014-06-12T15:04:09Z (GMT). No. of bitstreams: 2 arquivo1235_1.pdf: 4329445 bytes, checksum: 42252972f20f1e35509d7b60a910871c (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Nematoda é o grupo da meiofauna mais abundante e diverso nos sedimentos marinhos de mar profundo. Na Bacia de Campos, Sabatieria foi o gênero dominante em relação aos 186 encontrados, ocorrendo nas diferentes profundidades estudadas (750m, 1050m, 1350m, 1650m and 1950m), áreas (Norte e Sul) e estratos sedimentares (0-2cm e 2-5cm). Seis novas espécies desse gênero foram descritas para a Bacia de Campos, cada uma apresentando as seguintes características: Sabatieria spiculata sp. nov. é caraterizada pelo tamanho da espícula e a presença de um dente dorsal; S. paraspiculata sp. nov. pela forma da cauda e o diâmetro máximo do corpo; S. bitumen sp. nov. pela forma das espículas com uma projeção em forma de flecha na parte distal; S. subrotundicauda sp. nov. pela cauda arredondada e ovários refletidos; Sabatieria exilis sp. nov. por uma cabeça arredondada sem constricções, faringe curta com porção anterior cuticularizada; Sabatieria fidelis sp. nov. por possuir setas cefálicas e somáticas curtas, testículos distendidos e curtos, espículas direcionadas ventralmente e com uma terminação em forma de conta-gotas na parte distal e gubernáculo em forma de v . Ainda que Sabatieria tenha sido encontrada nas diferentes profundidades, existiu uma redução no número de indivíduos com o aumento da profundidade, com diferenças significativas entre a profundidade de 750 metros e as demais. S. spiculata e S. bitumen foram as espécies mais abundantes nas amostras. Esse gênero e suas espécies mostraram uma distribução preferencial (e significativa) no estrato sedimentar mais superficial (0-2 cm). Sabatieria e suas principais espécies (em abundância) apresentaram uma correlação positiva com o carbono orgânico e negativa com os teores de carbonatos. Esses resultados reforçam a importância de Sabatieria (e suas espécies) como os táxons mais abundantes de Nematoda nas áreas de Talude Continental, especialmente, nos sedimentos finos com níveis médio-altos de recursos orgânicos

Orientador: Herculano Penna Medina Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-03T15:01:28Z (GMT). No. of bitstreams: 1 Orsi_CintiaHotta_M.pdf: 7025269 bytes, checksum: a62f1a619d719384ad24501990040cdd (MD5) Previous issue date: 2003 / Mestrado

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: A molecular, morphological and biological characterisation of the genus Globodera (Nematoda: Heteroderidae) in South Africa is presented. The aims of the study were to determine the spread of the genus in South Africa; to study the systematics and describe the characteristics of the group and to gain a more complete understanding of the biology of the group as agricultural pests. Surveys were conducted in the Cape Floristic Region and in all the potato-producing areas of South Africa. The surveys unearthed new species of cyst nematodes and determined the spread of Globodera rostochiensis in the country. Phylogenetic analysis of sequences from ITS-rDNA was used to infer phylogenetic relationships among cyst nematodes from South Africa. The analyses established the distinct phylogenetic positions of cyst nematode populations from South Africa relative to an array of other cyst nematode species and indicated the existence of four new species of cyst nematodes. Analysis of random amplified polymorphic DNA (RAPD) banding patterns revealed intraspecific genetic variation amongst populations of Globodera rostochiensis. In order to provide molecular protocols for the accurate identification of South African cyst nematodes, species-specific primers and restriction enzymes were tested for their ability to discriminate between local Globodera spp. A combination of the molecular, morphological and morphometric characteristics of these populations were used to describe three new species of cyst nematodes. Experiments to determine the effect of storage temperature on the viability and hatching of South African populations of G. rostochiensis, showed differences in the responses of different populations to different storage temperatures. Experiments to determine the effect of field conditions on the viability and hatching of South African populations of G. rostochiensis, indicated that a decline in viable eggs in cysts from different populations occur, but suggests that the cysts will be able to survive for much longer in these soils than was expected. Spontaneous hatch was the main contributor to the decline of viability of cysts in the soil. Recording of soil temperatures in different locations indicated that the average temperature at 20 cm depth was approximately 20°C, the optimum temperature for the reproduction of G. rostochiensis, as confirmed by in vitro reproduction tests, which also showed that multiplication and survival is influenced negatively when the temperatures rise above 25°C. Reproduction on differential potato clones confirmed the pathotype of all the South African populations of G. rostochiensis as Ro1. After assessing the reproduction of G. rostochiensis on indigenous solanaceous plants, it was concluded that none of these plants induce substantial hatch in G. rostochiensis, nor do they support multiplication of the nematode. The results of this project have an impact on inquiries at all taxonomic levels, while also having an essential practical application in nematology. Knowledge of the distribution, pathogenicity, survival potential and reproduction capacity of Globodera species in South African soils are valuable for the design of effective management strategies as well as regulatory measures. / AFRIKAANSE OPSOMMING: ‘n Molekulêre, morfologiese en biologiese karakterisering van die genus Globodera (Nematoda: Heteroderidae) in Suid-Afrika word aangebied. Die doelwitte van die studieprojek was om die verspreiding van die genus in Suid-Afrika vas te stel, om die sistematiek van die groep te bestudeer en om ‘n meer volledige begrip van die biologie van die groep te bekom. Opnames is in die Kaapse Floristiese streek en in al die aartappelproduserende gebiede in die land gedoen. Tydens die opnames is nuwe sist nematode spesies gevind en die verspreiding van Globodera rostochiensis in Suid-Afrika is vasgestel. Filogenetiese analises van die basispaar opeenvolgings van ITS-rDNS is gebruik om die filogenetiese verwantskappe tussen die sist nematodes van Suid-Afrika vas te stel. Die spesifieke filogenetiese posisies van die nematodes, relatief tot ander spesies het gedui op die teenwoordigheid van 4 nuwe spesies. ‘n Analise van “random amplified polymorphic DNA” (RAPD) bandpatrone het intraspesifieke variasie tussen populasies van G. rostochiensis uitgewys. Diagnostiese tegnieke, aan die hand van spesies-spesifieke inleiers en restriksie-ensieme, is geevalueer vir hul vermoë om Globodera spesies van mekaar te onderskei. ‘n Kombinasie van molekulére, morfologiese en morfometriese karaktertrekke is gebruik vir die beskrywing van drie nuwe Globodera spesies. Eksperimente om die effek van verskillende temperature op die lewenskragtigheid en uitbroei van Suid-Afrikaanse populasies van G. rostochiensis vas te stel, het verskille in die reaksies van die poulasies uitgewys. Eksperimente om die effek van veldtoestande op die lewenskragtigheid en uitbroei van Suid-Afrikaanse populasies van G. rostochiensis vas te stel, het gewys dat alhoewel ‘n afname in die lewenskragtigheid van eiers plaasvind, sal die siste nog steeds langer in die grond oorleef as wat verwag is. Spontane uitbroei van eiers was die grootste oorsaak van die afname in lewenskragtigheid van siste in die grond. Die monitoring van grondtemperature in verskillende lokaliteite, het gewys dat die gemiddelde temperatuur, 20 cm onder die grond, nagenoeg 20°C was. Die optimum temperatuur vir die aanteling van G. rostochiensis, soos gewys deur in vitro toetse is ook 20°C, maar ‘n skerp daling vind plaas by temperature hoer as 25°C. Aanteling op verskillende aartappel cultivars, het gewys dat die patotipe van plaaslike populasies van G. rostochiensis, Ro1 is. Toetse op inheemse Solanum plante het gewys dat die plante nie goeie gashere vir G. rostochiensis is nie. Die bevindings van hierdie studieprojek het ‘n impak op die taksonomie van die groep en kennis van die verspreiding, patogenisiteit en oorlewing van die nematodes onder Suid-Afrikaanse toestande is van waarde vir die daarstelling van effektiewe beheerstrategiee en wetstoepaslike regulasies.

ROCHA, R. O. Exsudatos de sementes de soja [Glycine max (L.) Merrill]: caracterização proteômica e efeitos contra o nematoide das galhas Meloidogyne incognita. 2014. 110 f. Dissertação (Mestrado em Bioquímica) - Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2014. / Submitted by Daniel Eduardo Alencar da Silva (dealencar.silva@gmail.com) on 2015-01-20T17:27:19Z No. of bitstreams: 1 2014_dis_rorocha.pdf: 1719912 bytes, checksum: c736b320111d4f796644bb4667719c0e (MD5) / Approved for entry into archive by José Jairo Viana de Sousa(jairo@ufc.br) on 2015-12-10T21:28:55Z (GMT) No. of bitstreams: 1 2014_dis_rorocha.pdf: 1719912 bytes, checksum: c736b320111d4f796644bb4667719c0e (MD5) / Made available in DSpace on 2015-12-10T21:28:55Z (GMT). No. of bitstreams: 1 2014_dis_rorocha.pdf: 1719912 bytes, checksum: c736b320111d4f796644bb4667719c0e (MD5) Previous issue date: 2014 / Exudation is a defense mechanism presented by seeds, which release molecules to the soil during the germination process. These exudates, mainly composed by proteins and secondary metabolites, act interfering with the development of microorganisms. They represent a source of defense molecules with biotechnological potential to control soil-borne pathogens. In this context, soybean [Glycine max (L.) Merrill] stands as an ideal system in the study of plant-pathogen interaction due to its great economic value and the high content of seed proteins. The experimental activities presented in this thesis aimed to characterize the composition of seed exudates from two different soybean cultivars, which show different levels of performance in response to the root-knot nematode Meloidogyne incognita. Furthermore, the in vitro and in vivo effects of the seed exudates on this pathogen were evaluated. For this purpose, the exudates were obtained from soybean seeds (BRS-Pala:susceptible; BRS-Macota:resistant), soaked in 0.1 M sodium acetate, pH 5.0, during 18 hours. The gel-free proteomic analysis allowed identification of several defense-related proteins such as soybean agglutinin, Kunitz and Bowman-Birk trypsin inhibitors, and pathogenesis-related proteins. The qualitative analysis of secondary metabolites in the exudates also revealed the presence of phenols, triterpenoids, saponins, flavones, flavonols, and xanthones in both cultivars. The above exudates were dialyzed in 3.5 kDa cut-off membranes and assayed for bioactive proteins. The hemagglutinating (609.52 HU/mgP), trypsin (4.81 mg trypsin inhibited/mgP) and papain (30.48 IU/mgP) inhibitor, proteolytic (1.52 UAPr/mgP.min), and β-1, 3-glucanase (58.26 ηkatGLU/mgP) activities were higher for BRS-Pala. Otherwise, the peroxidase activity (0.218 UAP/mgP.min) predominated in BRS-Macota. The evaluation of anti-nematode activity against eggs and second stage juveniles (J2) revealed that both exudates were able to inhibit the hatching of M. incognita eggs as well as the J2 mobility. This nematostatic property is reflected in the infectivity of the parasite, reduced by the exuded protein at 0.13 mg/mL concentration. The results reinforce the idea that the exudation is related to the constitutive defense of the seeds, suggesting that the proteins present in the exudates can contribute to the protection against nematodes and possibly other plant enemies during the germination process. / A exsudação é um mecanismo de defesa apresentado por sementes que consiste na liberação de moléculas para o solo durante o processo de germinação. Esses exsudatos, compostos essencialmente de proteínas e metabólitos secundários, atuam interferindo no desenvolvimento de microrganismos, representando fontes para prospecção de moléculas de defesa com potencial biotecnológico, voltadas ao controle de patógenos de solo. Nesse contexto, a soja se destaca [Glycine max (L.) Merrill] como sistema ideal ao estudo das interações planta-patógeno, visto seu grande valor econômico e o alto teor de proteínas de seus grãos. Este trabalho teve como objetivos caracterizar a composição dos exsudatos de sementes de dois cultivares de soja, com diferentes índices de desempenho em resposta ao nematoide das galhas Meloidogyne incognita, e avaliar seus efeitos in vitro e in vivo sobre este fitopatógeno. Exsudatos foram obtidos a partir de sementes de soja (cultivares BRS-Pala: suscetível; BRS-Macota: resistente), embebidas em acetato de sódio 0,1 M, pH 5,0, por 18 horas. A análise proteômica comparativa livre de gel que permitiu a identificação de diversas proteínas relacionadas à defesa vegetal, tais como a aglutinina da soja, os inibidores de tripsina do tipo Kunitz e Bowman-Birk e proteínas relacionadas à patogênese. A análise qualitativa de metabólitos secundários nos exsudatos revelou a presença de fenóis, triterpenóides, saponinas, flavonas, flavonóis e xantonas em ambas as cultivares. Posteriormente, estes exsudatos foram dialisados em membranas de diálise com exclusão de 3,5 kDa e submetidos à dosagem de proteínas bioativas. As atividades hemaglutinante (609,52 UH/mgP), inibitórias de tripsina (4,81 mg tripsina inibida/mgP) e papaína (30,48 UI/mgP), proteolítica (1,52 UAPr/mgP.min) e β-1,3-glucanásica (58,26 ηkatGLU/mgP) foram maiores para a cultivar BRS-Pala. Já a atividade peroxidásica (0,218 UAP/mgP.min) predominou na cultivar BRS-Macota, A avaliação da atividade nematicida sobre ovos e juvenis de segundo estádio (J2), usando exsudatos dialisados, revelou que ambos os exsudatos são capazes de inibir a eclosão de M. incognita, bem como a mobilidade dos juvenis desta espécie. Esta propriedade nematostática se reflete na infectividade do parasita, reduzida pelo tratamento com proteínas exsudadas na concentração de 0,13 mg/mL. Os resultados reforçam a ideia de que a exsudação das sementes está relacionada à defesa constitutiva deste órgão vegetal, sugerindo que proteínas presentes nos exsudatos podem promover proteção contra nematoides durante o processo germinativo.

Please read the Summary/Samevatting on pp 138-141 in chapter 6 of this document / Thesis (PhD (Plant Pathology))--University of Pretoria, 2006. / Microbiology and Plant Pathology / unrestricted

published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in fulfilment of the requirements for the degree of Master of Science. May 2013 / The purpose of the study was to isolate and identify indigenous nematode species and use them as model organisms for studying the responses of indigenous entomopathogenic nematodes (EPNs) to soil desiccation, soil rehydration, and also to study their behaviour with regards to the infection and location of insect larvae, Galleria mellonella in an 18cm column filled with sterilised sandy loamy soil. Two unknown nematodes were isolated from soil samples collected in Walkerville, South of Johannesburg and their sequences were found to have high affinity to Steinernema australe (accession number FJ235125) and Heterorhabditis bacteriophora isolate 56-C (FJ217351) when aligned with existing sequences in the NCBI database. Furthermore, a polymerase chain reaction was used to amplify the 16S rDNA region in order to identify bacterial symbiots of these EPNs. Symbiotic bacteria isolated from the Heterorhabditis spp had high affinity to Photorhabdus sp carborca (JF12345). Desiccation tolerance studies revealed that EPN5T and EPN3T were able to withstand desiccated conditions or continuous dehydration for 20 days. EPN5T caused 80% larval mortality after day 20 when the last row of Petri dishes was rehydrated. EPN3T caused only 60% larval mortality. All of the sandy controls gave 0% larval mortality by day 20. Comparative dose-response assays involved exposing G. mellonella insect larvae to different IJs concentrations (0, 5, 25, 100, 300 and 500 IJs/ml) were carried for both EPN5T and EPN3T. Larval mortality was recorded daily over a week. Insect mortality was high for both S. australe and H. bacteriphora, at 100IJs\ml, 300 IJs\ml and 500 IJs\ml. Mortality was observed within 48 to 96 hours and insects larvae showed signs of infection after 48hours. Significant differences were observed at EPN concentrations containing 5 IJs/ml and 25 IJs/ml. At these low IJ concentrations H. bacteriphora was able to kill 20% of the larvae by day 3 while S. australe displayed mortality only after day 4 and 5 for the two respective IJ concentrations. The significance of this observation was supported by the two-way Post-hoc analysis. Further studies were conducted to investigate the effect of soil humidity on EPNs behaviour in a column of soil. Results supported that humidity was crucial for EPNs locomotion or mobility and infection efficiency, as 100% mortality was observed in all columns by day 4. The study also investigated different IJ application concentrations in order to determine suitable field application doses. Even at the lowest IJ concentration of both EPNs 33.3% mortality was observed in each column. H. bacteriophora displayed increased mobility because high mortality percentage was obtained within 48hours in almost all three arenas of the column, proving that this species is an effective cruiser foraging deeper into the soil. S. australe was capable of cruising further down to 18cm searching for host as high mortality was observed even at the deeper or the bottom arena near the bottom of the soil column. Lastly field capacity was determined where the sandy loamy soil was saturated with water and allowed to drain so as to remove excess water from the 8 vertical columns for 48hours, resulting in a soil moisture content associated with the soil’s field capacity for water. Overall results of this study gave ideas for IJ formulation IJ storage and IJ application strategies of the identified EPNs which proved to have promising potential as biological control agents.

1v. (various pagings) : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (D.Sc.1974) from the Dept. of Entomology, University of Adelaide

Bibliography: leaves 155-193 / iv, 193 leaves, [48] leaves of plates : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Zoology, 1986

Thesis (M. Phil.)--University of Hong Kong, 1979.