Orientador: Nilton Luiz de Souza / Resumo: O trabalho foi realizado nas instalações do Departamento de Produção Vegetal/Defesa Fitossanitária da Faculdade de Ciências Agronômicas-UNESP (22º51'S e 48º26'W)- Botucatu/SP e consistiu da instalação de dois experimentos idênticos em épocas distintas com duas etapas cada. A primeira destas objetivou verificar o efeito da solarização sobre a comunidade nativa de Pseudomonas spp. fluorescentes no campo e em túnel plástico. Nesta fase, monitorou-se a população das bactérias aos 0, 7, 14, 21, 28 e 35 dias durante a solarização. Na segunda etapa, verificou-se a indução de supressividade do solo, no controle da doença, em feijoeiro na cultivar 'IAC Carioca', causada por Rhizoctonia solani GA 4 HGI, agente causal do 'damping-off' do feijoeiro, através do emprego do solo previamente solarizado ou não, transportado para vasos, sob condições de casa-de-vegetação. Monitorou-se a população das bactérias em meio B de King e o índice de severidade de R. solani aos 7, 14 e 21 dias após a semeadura através de escala de notas. Para a inoculação o fungo foi cultivado em substrato areno-orgânico e incorporado ao solo na proporção de 0,5% p/v. A detecção endofítica ou epífita de Pseudomonas spp. fluorescentes em sementes de feijão, o teste de antagonismo a Rhizoctonia solani e a caracterização genérica através de testes morfológicos e bioquímicos, foram feitos em condições de laboratório. O tempo de solarização foi de 35 dias nos períodos de 19/11/99 a 24/12/99 e de 17/02/00 a 23/03/00. Observou-se maiores temperaturas em túnel plástico nos dois períodos. As maiores médias máximas no campo e túnel plástico foram maiores no primeiro período do que no segundo. A solarização e ausência de cobertura vegetal diminuíram a população das bactérias a níveis indetectáveis no campo e túnel... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: The study was carried out at the Departament of Plant Production - UNESP- Botucatu/SP, Brazil (22º51'S and 48º26'W). The study consisted of two identical experiments installed in different periods with two stages each. The objective of the first experiment was to verify the effect of solarization on the native community of fluorescent Pseudomonas spp. under field and plastic tunnel conditions. The bacterium population was monitored at 0, 7, 14, 21, 28 and 35 days of solarization. In the second experiment, it was verified a possible induction of soil suppressiveness to control disease, caused by Rhyzoctonia solani GA 4 HGI on bean 'IAC Carioca', through solarized or not solarized soil transferred to vases, under greenhouse conditions. The bacterium population was monitored in King's B medium and the severity rate of R. solani was determined at the 7, 14 and 21 days after sowing using a scale of notes. R. solani was cultivated for inoculation in sand-organic substratum and incorporated at the soil in the 0.5 w/v proportion. The detection of the endophytic or epiphytic forms of the fluorescent Pseudomonas spp. in bean seeds, the antagonism test against Rhizoctonia solani and the generic characterization by the morphological and biochemistry tests were made under laboratory conditions. The extension of the solarization was 35 days, from 11/19/00 to 12/24/00 and from 02/17/00 to 03/23/00. The greatest temperatures were observed in plastic tunnel in both periods. The greatest maximum media temperatures were bigger in the first period than in the second one. The soil solarization and the absence of vegetable mulching decreased the bacteria population at undetected levels in the field and tunnel. The soil solarization in the field and tunnel did not induce soil suppressiveness to R. solani. It was not observed endophytic and epiphytic forms of... (Complete abstract, click electronic address below). / Mestre

Orientador: Kurozawa Chukichi / Resumo: O presente trabalho visou verificar a ação "in vitro" e "in vivo" de alguns fungicidas e do indutor de resistência acibenzolar-S-methyl (BTH) no controle da pinta preta do tomateiro e seus reflexos na produção. A ação "in vitro" de fungicidas, nas concentrações de 0, 1, 10 e 100 μgmL-1 do ingrediente ativo, foi verificada com base no crescimento micelial, germinação de conídios e efeito anti-esporulante sobre A. solani. Em condições de casa de vegetação foram estudadas as ações: preventiva, residual e curativa de fungicidas em cultivares com diferentes níveis de resistência a pinta preta. Em experimentos de campo, realizados nos municípios paulistas de Sumaré (1999), Socorro (2000) e Bragança Paulista (2000 e 2001), foi avaliada a ação de diferentes grupos fungicidas e acibenzolar-S-methyl (isolado, em mistura com fungicidas e em programas de aplicação) sobre: a severidade da doença (folíolos e hastes); redução de área foliar; incidência de frutos sadios; doentes e danificados pelo sol; massa fresca de frutos sadios, produção em kilos por 10 plantas e porcentagem de frutos grandes, médios e pequenos (Bragança Paulista, 2001). Todos os fungicidas apresentaram ação positiva e diferenciada para todos os parâmetros avaliados, em função das características inerentes de cada princípio ativo. Os maiores potenciais de controle foram verificados para os fungicidas com maior especificidade e ação sistêmica... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: The aim of this study was to verify the "in-vitro" and in-vivo effectiveness of various fungicides and plant activator acibenzolar-S-methyl (BTH) in the control of tomato early blight and its effects on yield. The in-vitro effect of the fungicides, in the concentrations 0, 1, 10 and 100 μgmL-1 of the active ingredient, was assessed based on mycelial growth, conidial germination, and the antisporulating effect on A. solani. The various groups of fungicides were studied to compare their preventative, residual and curative efficacy, in greenhouse environment. Field tests were conducted in the state of São Paulo, Brazil, in the countries of Sumaré (1999), Socorro (2000) and Bragança Paulista (2000 and 2001), to compare the effect of various fungicide groups and acibenzolar-S-methyl (alone, mixed with the fungicides, or applied in conjunction with fungicidal treatments) on various parameters: the severity of the disease (leaflets and stems); percentage of leaf drop; relative numbers of healthy fruit as compared to diseased or sun-damaged fruit; yield in kg per 10 plants; and the relative percentages of large, medium and small-sized fruits (Bragança Paulista, 2001). All the fungicides presented a positive effect on all of the parameters evaluated, consistent with the active ingredients of each. The greatest efficacies of control were shown by systemic, more-specific fungicides. In regard to mycelial growth and conidial germination, the greatest inhibition percentages were obtained with metconazole, tebuconazole, difenoconazole, iprodione, cyprodinil, procymidone, prochloraz, fluazinam and pyrimethanil. The fungicides kresoxim methyl, azoxystrobin, pyraclostrobin+methiram, fenamidone+chlorothalonil and famoxadone+mancozeb presented an intermediate degree of inhibition on the mycelial growth and complete inhibition of conidial germination at concentrations of 1 μgmL-1 and above... (Complete abstract, click electronic address below). / Mestre

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Thèse (M.Sc.)--Université Laval, 2007. / Bibliogr.: f. 52-58. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

The aim of this study was to develop a genetic transformation system for the plant pathogenic fungus Rhizoctonia solani (teliomorph, Thanatephprus cucumeris Frank [Donk]). The availability of a transformation system would allow us to study gene exchange, epidemiology, and to use techniques such as gene disruption or gene silencing to investigate the role of fungal enzymes in pathogenesis. The approach adopted was to use Agrobacterium tumefaciens to transform the fungus as reports in the literature suggested that this was the most efficient and easiest method to use. As a preliminary test, Fusarium oxysporum was transformed using a binary vector (pBINAN) containing a hygromycin resistance gene under control of an ascomycete promoter and terminator. Hygromycin resistant transformants were obtained after co-incubation of fungal conidia with the bacterium. The presence of the transgene was confirmed by analysis of DNA. The number of transformants depended on the genetic background of the A tumefaciens. Strains AGLO or AGRO gave higher numbers of transformants compared to LBA4404. No transformants were obtained when the hygromycin gene was under control of a basidiomycete (pBINHL1), or a plant (CaMV35S) promoter. Since the basidiomycete promoter used in pBINHL1 originates from Ustilago maydis, the vector was tested by transformation of Ustilago cynodontis. Stable transformants of U cynodontis were obtained with this vector. A series of experiments were carried out on transformation of R. solani mycelium. Both the protoplast and the Agrobacterium transformation methods were tested. Parameters affecting protoplast production and regeneration were examined. Protoplast production varied with the age of the mycelium, with the osmotic stabilizer used, and with time of treatment with protoplasting enzymes. Regeneration of protoplasts was also affected by the osmotic stabilizer and the growth medium. Transformation of several isolates from different anastomosis groups (AG) was attempted by inducing protoplasts to take up DNA using polyethyleneglycol. Two plasmids were used; (1) pAN7-1 containing the resistance gene under control of an ascomycete promoter, and (2) pHL-1 in which the resistance gene is under control of a basidiomycete promoter. No transformants were obtained. Attempts were then made to transform mycelium and protoplasts using A tumefaciens. The experiments used both mycelium and protoplasts as the recipient. A number of small resistant colonies were obtained using binary plasmid (pBINHL1) in which mycelium was transformed with the resistance gene was driven by the basidiomycete promoter. On transfer to fresh medium these colonies would grow to about 2cm diameter, and then stop growing. On a second transfer to fresh medium they failed to show any growth. No resistant colonies were obtained from A. tumefaciens transformation of protoplasts. To improve transformation efficiency, a vector was constructed in which the hygromycin resistance gene was fused to an R solani laccase promoter sequence. No resistant colonies were obtained using this vector. Further experiments were carried out using a hygromycin resistance gene specially modified for expression in basidiomycetes by the insertion of artificial introns in the 5’ and 3’ untranslated regions, and a number of AT to CG conversions in the coding region. Most of the recipient isolates gave transformants with the unstable resistance phenotype. However, one AG 6 isolate gave transformants with a stable resistance phenotype. Of six transformants recovered from this isolate, five were shown by PCR and southern blotting to contain the transgene. In four of these transformants the resistance phenotype was stable in the absence of selection.

Thesis (Ph. D.)--University of Adelaide, Dept. of Soil Science, 1996. / Includes bibliographical references (leaves 184-209).

Thesis (M.S.) in Plant, Soil and Environmental Sciences--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 79-84).

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains viii, 70 p. : ill. Includes abstract. Includes bibliographical references (p. 64-70).

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