Made available in DSpace on 2014-06-11T19:23:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-02Bitstream added on 2014-06-13T20:30:11Z : No. of bitstreams: 1 bongiovani_ram_me_sjrp.pdf: 2319132 bytes, checksum: e7d65e5bb475e25f1407badd2bab2ddd (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os exopolissacarídeos (EPS) são polímeros produzidos por uma grande variedade de microrganismos e podem possuir propriedades físicas, estruturais e químicas diferentes. Considerando o interesse crescente das indústrias na busca de polissacarídeos que apresentem comportamento reológico compatível com sua aplicação, tanto nos setores de alimentos como farmacêutico, cosmético e têxtil, pesquisas vêm sendo realizadas com a esperança da descoberta de novas moléculas promissoras para tais aplicações. O objetivo deste trabalho foi determinar as características reológicas do exopolissacarídeo (botriosferana) produzido pelo Botryosphaeria rhodina MAMB-05 em três fontes de carbono: glucose (EPSGLU), sacarose (EPSSAC) e frutose (EPSFRU). A análise da composição monossacarídica, após hidrólise ácida, mostrou que todos os polímeros são constituídos exclusivamente por glucose e a cromatografia de filtração em gel indicou baixo grau de polidispersividade. Experimentos com o corante Congo Red evidenciaram a presença de tripla hélice nos três polímeros produzidos pelo fungo B. rhodina MAMB-05. Os três polissacarídeos comportaram-se como fluidos não-Newtoniano com características de soluções pseudoplásticas e tixotrópicas e com diminuição da viscosidade quando em presença de NaCl. As soluções aquosas de EPSGLU, EPSSAC e EPSFRU apresentaram comportamento viscoelástico, com características de gel forte em 5 e 25°C, não sofrendo mudanças no comportamento, mesmo em presença de NaCl, a 25°C. As soluções polissacarídeos mantiveram as características de géis fortes, com propriedades termoestáveis e termorresistentes, entre 5 a 95°C de temperatura. Esses resultados permitiram concluir que os EPS produzidos pelo fungo B. rhodina MAMB-05 possuem propriedades químicas e físicas, passíveis de utilização nas indústrias de alimentos, farmacêutica, cosmética e biomédica. / Exopolysaccharides (EPS) are polymers produced by a great variety of microorganisms and can possess different physical and chemical properties, and structural features. Considering the growing interest in commercial applications of polysaccharides that show rheological compatible behavior within the application, as in the food, pharmaceutical, cosmetic and textile sectors, research have been developed in attempts to discover new promising biomolecules for such applications. The objective of the work presented was to determine the rheological characteristics of the exopolysaccharide botryosphaeran produced by Botryosphaeria rhodina MAMB-05 on three different sole carbon sources: glucose (EPSGLU), sucrose (EPSSUC) and fructose (EPSFRU). The analysis of monosaccharide composition, after acid hydrolysis, showed glucose as the only component and the gel permeation chromatography indicated that the EPSs have an excellent purity grade. All three biopolymers produced by B. rhodina MAMB-05 were found to exist in the triple helix conformational state. The three exopolysaccharides showed non-Newtonian behavior, with pseudoplastic and thixotropic characteristics, and showed a slight decrease in viscosity in presence of NaCl. The three biopolymer gels showed viscoelastic behavior, with characteristics of strong gelling at 5 ºC and 25 ºC, without suffering behavioral changes, even in the presence of NaCl at 25 ºC. The polysaccharide solutions kept the strong gel characteristics possessing thermo-stable and thermo-resistant properties when evaluating the influence of temperature (5 – 95 ºC) over the viscoelastic behavior of solutions. The results concluded that the EPS’s produced by fungus B. rhodina MAMB-05 have physical and chemical properties amenable for use in the food, pharmaceutical, cosmetic and biomedical industries.

Made available in DSpace on 2014-06-11T19:28:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-15Bitstream added on 2014-06-13T18:58:00Z : No. of bitstreams: 1 souza_hg_me_botfca.pdf: 1426991 bytes, checksum: 7c8beacd93595a04b7e0ef427ee21af6 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O termo cancro é utilizado para designar lesões localizadas na casca do caule de plantas lenhosas que podem resultar no anelamento do caule e no secamento da parte superior da copa e a morte da planta. A melhor opção para o controle da doença é a resistência genética dos indivíduos quanto ao patógeno utilizado. Com o objetivo de estudar o comportamento de resistência e mecanismos moleculares de clones dos parentais e das progênies de eucalipto quanto ao cancro causado por Chrysoporthe cubensis e Botryosphaeria sp. foram executados ensaios em casa de vegetação e em campo. Os isolados utilizados foram Chrysoporthe cubensis e Botryosphaeria sp. sendo produzidos em meio BDA e inoculados nos indivíduos pelo método do disco. A avaliação foi realizada 60 dias após a inoculação, medindo a área da lesão de cada material. Para o patógeno C. cubensis inoculados nos parentais foi encontrado uma média de 3,20 e 6,14 cm2 de área de lesão do tronco causado pelos isolados provenientes de Piracicaba e Bofete, respectivamente, enquanto que para Botryosphaeria sp. a média variou de 7,29 cm ² a 9,72cm ² da área da lesão. Dos indivíduos testados, com C. cubensis, foram encontrados 46,66% de plantas classificadas como resistentes; 6,67% plantas moderadamente resistente, 13,33% planta moderadamente suscetíveis e 33,34% plantas suscetíveis. Já para o teste de clones com Botryosphaeria sp. verificou-se 91,67% resistentes, 5% moderadamente resistentes, 1,67% moderadamente suscetível e 1,67% suscetíveis. As variâncias fenotípicas encontradas foram de 41,32 a 0,23 inoculados com C. cubensis e 0,285 a 156,88, quando inoculados com Bothyosphaeria sp. Os coeficientes de variação foram de 125% a 15,05% para C. cubensis e 29,86% a 101,13% para Bothyosphaeria sp. Os resultados indicam que os materiais genéticos testados possuem boa fonte de resistência para os dois fitopatógenos... / The term canker is used to assign to injuries located in the bark of stems of woody plants that can result in the anelamento of stems and drying of the superior part of the crown and the death of the plant. The best option for the control of the illness is the resistance genetic of the individuals concerning to the used patógeno. The objective of this study the molecular behavior of resistance and mechanisms of clonals of parental and the lineages the eucalyptus concerning the canker caused for Chrysoporthe cubensis and Dothiorella sp. The essays executed in the greenhouse and field. The isolated ones used concerning Chrysoporthe cubensis and Dothiorella sp. being produced in inoculated medium BDA and in the individuals for the method of the disk. The evaluation was concluded 60 days after the inoculation, measuring the area of the injury of each material. For pathogeno C. cubensis inoculated in the parental ones a 6,14 was found average of 3,20 and cm² of area of isolated injury of the trunk caused for the proceeding ones from Piracicaba and Bofete, respectively. The average of the area of the injury for the studied lineages varied of 7,29 cm ² 9,72cm ² for Dothiorella sp. The clonals inoculated C. cubensis were grouped into the categories HS (highly susceptible – 33,34%), MS (moderately susceptible -13,3%), MR (moderately resistant- 6,67%), and HR (highly resistant -46,66%). The clonal tested, with Botryosphaeria sp., verified resistant 91.67%, 5% moderately resistant, 1.67% moderately susceptible and 5,26% susceptible. The phenotypic variation found was from 41,32 to 0,23, inoculated with C. cubensis while Botryosphaeria sp from 0,285 to156,88. The coefficient of variation from 125% to 15,95% for C. cubensis and 29,86% to 101,13% for Botryosphaeria sp. The results indicate that the tested genetic materials possess good source of resistance for the two fitopatógenos tested... (Complete abstract click electronic access below)

Orientador: Edson Luis Furtado / Banca: Marli Teixiera de Almeida Minhoni / Banca: Celso Garcia Auer / Resumo: O termo cancro é utilizado para designar lesões localizadas na casca do caule de plantas lenhosas que podem resultar no anelamento do caule e no secamento da parte superior da copa e a morte da planta. A melhor opção para o controle da doença é a resistência genética dos indivíduos quanto ao patógeno utilizado. Com o objetivo de estudar o comportamento de resistência e mecanismos moleculares de clones dos parentais e das progênies de eucalipto quanto ao cancro causado por Chrysoporthe cubensis e Botryosphaeria sp. foram executados ensaios em casa de vegetação e em campo. Os isolados utilizados foram Chrysoporthe cubensis e Botryosphaeria sp. sendo produzidos em meio BDA e inoculados nos indivíduos pelo método do disco. A avaliação foi realizada 60 dias após a inoculação, medindo a área da lesão de cada material. Para o patógeno C. cubensis inoculados nos parentais foi encontrado uma média de 3,20 e 6,14 cm2 de área de lesão do tronco causado pelos isolados provenientes de Piracicaba e Bofete, respectivamente, enquanto que para Botryosphaeria sp. a média variou de 7,29 cm ² a 9,72cm ² da área da lesão. Dos indivíduos testados, com C. cubensis, foram encontrados 46,66% de plantas classificadas como resistentes; 6,67% plantas moderadamente resistente, 13,33% planta moderadamente suscetíveis e 33,34% plantas suscetíveis. Já para o teste de clones com Botryosphaeria sp. verificou-se 91,67% resistentes, 5% moderadamente resistentes, 1,67% moderadamente suscetível e 1,67% suscetíveis. As variâncias fenotípicas encontradas foram de 41,32 a 0,23 inoculados com C. cubensis e 0,285 a 156,88, quando inoculados com Bothyosphaeria sp. Os coeficientes de variação foram de 125% a 15,05% para C. cubensis e 29,86% a 101,13% para Bothyosphaeria sp. Os resultados indicam que os materiais genéticos testados possuem boa fonte de resistência para os dois fitopatógenos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The term canker is used to assign to injuries located in the bark of stems of woody plants that can result in the anelamento of stems and drying of the superior part of the crown and the death of the plant. The best option for the control of the illness is the resistance genetic of the individuals concerning to the used patógeno. The objective of this study the molecular behavior of resistance and mechanisms of clonals of parental and the lineages the eucalyptus concerning the canker caused for Chrysoporthe cubensis and Dothiorella sp. The essays executed in the greenhouse and field. The isolated ones used concerning Chrysoporthe cubensis and Dothiorella sp. being produced in inoculated medium BDA and in the individuals for the method of the disk. The evaluation was concluded 60 days after the inoculation, measuring the area of the injury of each material. For pathogeno C. cubensis inoculated in the parental ones a 6,14 was found average of 3,20 and cm² of area of isolated injury of the trunk caused for the proceeding ones from Piracicaba and Bofete, respectively. The average of the area of the injury for the studied lineages varied of 7,29 cm ² 9,72cm ² for Dothiorella sp. The clonals inoculated C. cubensis were grouped into the categories HS (highly susceptible - 33,34%), MS (moderately susceptible -13,3%), MR (moderately resistant- 6,67%), and HR (highly resistant -46,66%). The clonal tested, with Botryosphaeria sp., verified resistant 91.67%, 5% moderately resistant, 1.67% moderately susceptible and 5,26% susceptible. The phenotypic variation found was from 41,32 to 0,23, inoculated with C. cubensis while Botryosphaeria sp from 0,285 to156,88. The coefficient of variation from 125% to 15,95% for C. cubensis and 29,86% to 101,13% for Botryosphaeria sp. The results indicate that the tested genetic materials possess good source of resistance for the two fitopatógenos tested... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2016-06-02T20:34:16Z (GMT). No. of bitstreams: 1 2103.pdf: 9010606 bytes, checksum: 6ec32b7b3b1e18e59d2b173d7cd4775b (MD5) Previous issue date: 2007-11-23 / Universidade Federal de Minas Gerais / This work shows the isolation, identification of microorganisms from the species Khaya ivorensis and the identification of the pathogen that is attacking this plant on Bahia state (Brazil). In total seven strains of microorganisms from K. Ivorensis were isolated, but only six were identified. Two of them, Penicillium spp., Rhizopus spp., were identified according to their characteristics macro and micro morphological structures vegetative and reproductive. Four fungi were identified by the regions ITS 1 and/or ITS 2 of DNAr, by its morphological and microscopic characteristics. In addition, the Blast of the sequences of these regions confirmed the presence of the Pestalotiopsis crassiuscula 96%, Phomopsis sojae 95%, Lasiodiplodia theobromae, and its telemorfo Botryosphaeria rhodina 98%. Literature shows that Botryosphaeria rhodina is common in disease Canker in plant, similar occur in K. ivorensis, suggesting that this fungi is the pathogen in specie studded. After the identification of Khaya pathogen it was studded, yielding to isolation and identification of sixteen compounds from different classes: Des-methyl lasiodiplodin, lasiodiplodin, isocoumarin, two derivatives γ-butirolactones (4-propil-3-carbonyl-2- methyl-4-butanolideo and 4-propil-2-carbonyl-3-methyl-4-butenolideo), 11- hidroxijasmônic acid, 5-hidroximethylfurfural, tirosol, ergosterol, peroxido de ergosterol, steroids (stigmastenon, sitostenon and campestenon), nucleosídeos (5 - inosil, uridine e uracila), manitol and one triglycerides. Both derivatives γ- butirolactonas appear to be new in literature. The isolated compounds were identified by Nuclear Magnetic Ressonance 1D and 2D and Mass Spectrometry. The limonoids methyl angolenasate isolated in large amount from K. ivorensis symptomatic and 7- deacetoxy-7-oxogedunin isolated from Carapa guianensis, were bioassayed against the microorganisms Penicillium ssp., Phomopsis sojae and Botryosphaeria rhodina, in order to analyze if these fungi modify the structure of compounds. However, in some experiments were not observe any difference and in others, only hypothesis can be done by MS analyze. In a complementary study, compounds lasiodiplodin, ergosterol, 5 -inosil and mannitol were assayed as inhibitor of ATP synthesis, and only lasiodiplodin presented good results. / Este trabalho apresenta o isolamento, a identificação de microorganismos da espécie Khaya ivorensis e a identificação do patógeno que vem atacando esta espécie na Bahia. Foram isolados, no total, sete grupos de microorganismos da espécie K. ivorensis, mas apenas seis foram identificadas. Dois deles, Penicillium spp., Rhizopus spp., foram identificados de acordo com suas características macro e micro morfológico das estruturas vegetativas e reprodutivas. Quatro fungos foram identificados pelas regiões ITS 1 e/ou ITS 2 do DNAr, pelas suas características morfológicas e microscópicas e o Blast das seqüências das referidas regiões indicaram ser Pestalotiopsis crassiuscula 96%, Phomopsis sojae 95%, Lasiodiplodia theobromae, além de seu telemorfo Botryosphaeria rhodina 98%. Considerando o potencial de fitopatogênia descrito na literatura para os gêneros encontrados, a freqüência e localização dos fungos isolados, pode-se afirmar que Botryosphaeria rhodina é o agente causal da doença do plantio de K. ivorensis na Bahia. Após a identificação do patógeno de Khaya fez-se o estudo fitoquímico deste fungo, levando ao isolamento e identificação de 19 substâncias de diferentes classes: des-metil lasiodiplodina, lasiodiplodina, isocumarina, dois derivados γ- butirolactonas (4-propil-3-carbonil-2-metil-4-butanolideo e 4-propil-2-carbonil-3-metil- 4-butenolideo), ácido 11-hidroxijasmônico, 5-hidroximetilfurfural, tirosol, ergosterol, peróxido de ergosterol, esteróides (estigmastenona, sitostenona e campestenona), nucleosídeos (5 -inosil, uridina e uracila), manitol e um triglicerideo, dentre estas substâncias os dois derivados γ-butirolactonas possivelmente são novos na literatura. Os compostos isolados foram identificados pelas técnicas de Ressonância Magnética Nuclear 1D e 2D e por Espectrometria de massas. Foi realizado o experimento de biotransformação com os limonóides angolesato de metila isolado em grande quantidade de K. ivorensis sintomática e 7-desacetoxi-7-oxogedunina isolado de Carapa guianensis, frente aos microorganismos Penicillium ssp., Phomopsis sojae e Botryosphaeria rhodina, para verificar se ocorria ou não a modificação destes compostos junto aos fungos. No entanto, em alguns experimentos não observou-se nenhuma diferença e em outros, apenas supõem-se que tenha ocorrido a modificação. Em um estudo complementar, realizou-se ensaios frente a síntese de ATP com os compostos lasiodiplodina, ergosterol, 5 -inosil e do manitol, sendo que somente a lasiodiplodina apresentou uma boa inibição.

Memoria para optar al Título Profesional de Ingeniero Agrónomo / En los últimos años, la enfermedad descrita como “Botryosphaeria dieback”, se ha transformado en un grave problema al no existir un método de control químico efectivo, potenciando la búsqueda de alternativas de control biológico eficaces en limitar el daño provocado por patógenos de la madera de la vid. Por lo anterior, el objetivo de esta investigación fue evaluar la acción de distintos biocontroladores sobre Diplodia seriata, que es el principal agente asociado en Chile al decaimiento y muerte del brazo de la vid. Se evaluaron distintos biocontroladores, fungosos (Trizian 1, Trizian 2, Closea 1, Producto comercial a base de Trichoderma spp. (Trichoderma harzianum cepa Queule, T. virens cepa Sherwood, T. parceramosum cepa Traile)) y bacterianos (Ballus 1, Ballus 2 y Producto comercial a base de Streptomyces lydicus WYEC 108). Estos tratamientos se compararon con un control químico a base de benomilo más mancozeb y controles inoculados y no inoculados con el patógeno. La evaluación se realizó mediante la determinación del índice de inhibición de la lesión en cada uno de los tratamientos. Se utilizaron sarmientos no enraizados de uva de mesa cv. Thompson Seedless, en los cuales se realizó una herida de 0,5 cm de diámetro. Una vez aplicados los tratamientos con los diferentes biocontroladores, se inocularon los sarmientos con un disco de micelio de D. seriata, cubriendo la zona de infección con parafilm. Los tratamientos fueron incubados por 30 días a una temperatura promedio de 20,3°C y una humedad relativa sobre el 98%. La inoculación con el patógeno se realizó en dos tiempos: 1 (tiempo 1) y 96 horas (tiempo 2) después de efectuados los tratamientos correspondientes. Los resultados mostraron que el mejor tratamiento fue el fungicida comercial con un 76,7% y 30,6% de eficacia tanto para el tiempo 1 como para el tiempo 2 respectivamente. Los mejores resultados de biocontrol con antagonistas bacterianos, se obtuvieron con el producto comercial a base de Streptomyces lydicus WYEC 108 y Ballus 2 con un índice de inhibición de 40,9% y 39,7%; menor porcentaje es el que obtuvo Ballus 1 alcanzando un índice de inhibición de 20%, en el tiempo 1. Los tratamientos en base a biocontroladores fúngicos que incluían Trichoderma spp.: producto comercial, Trizian 2 y Trizian 1, presentaron un índice de inhibición de 30,4%; 29% y 3,9% respectivamente en el tiempo 1, reduciendo a 0% la inhibición de D. seriata en el tiempo 2. A su vez Closea 1 logró un 20,3% de inhibición en el tiempo 1, siendo el único tratamiento que mejora su acción de biocontrol al aumentar el tiempo de inoculación del patógeno, alcanzando un 25,8% de inhibición en el tiempo 2. / In last years, the disease named "Botryosphaeria dieback", has been a serious problem due to ineffective chemical control methods. This has enhanced the search of effective biological control alternatives to limit the damage caused by trunk pathogens in grapevines. Therefore, the aim of this study was to evaluate the action of different biocontrollers on Diplodia seriata, which is the main agent of shoots decay and death in the vineyards of Chile. Several biocontrollers were evaluated, fungal (Trizian 1, Trizian 2, Closea 1, commercial product based on Trichoderma spp. (Trichoderma harzianum strain Queule, T. virens strain Sherwood, T. parceramosum strain Traile)) and bacterial (Ballus 1, Ballus 2 and commercial product based Streptomyces lydicus WYEC 108). These treatments were compared with a chemical control based on benomilo more mancozed and inoculated and uninoculated controls with the pathogen. The evaluation was made establishing the inhibition index of the lesion for each of the treatments. Unrooted canes of Thompson Seedless grapevines were used, in which a wound diameter of 0.5 cm was made. After applying the different biocontrollers treatments, the canes were inoculated with a mycelium disc of D. seriata, covering the area of infection with parafilm. Treatments were incubated for 30 days at 20.3°C on average and in a relative humidity above 98%. Inoculation with the pathogen was performed in two occasions: 1 (time 1) and 96 hours (time 2) after the corresponding treatments. The results showed that the best treatment was the commercial fungicide with 76.7% and 30.6% efficiency in time 1 and time 2, respectively. The best results of biocontrollers with bacterial antagonists were obtained with the commercial product based on Streptomyces lydicus WYEC 108 and Ballus 2 with an inhibition percentage of 40.9% and 39.7% respectively; the lowest percentage was the one managed with Ballus 1, reaching an inhibition index of 20% in time 1. Treatments based on fungal biocontrollers, as Trichoderma spp.: commercial product, Trizian 2 and Trizian 1 showed an inhibition percentage of 30.4%; 29% and 3.9% respectively at time 1, reducing to 0% inhibition of D. seriata in time 2. Closea 1 achieved a 20.3% inhibition at time 1, being the only treatment that enhanced the action as a biocontroller with increasing time of pathogen inoculation, reaching a 25.8% inhibition at time 2.

Orientador: Edson Luiz Furtado / Banca: Wilson Story Venancio / Banca: Cesar Junior Bueno / Banca: William Mario de Carvalho Nunes / Banca: Christiane Ceriani Aparecido / Resumo: A seca de ponteiro, causada pelo fungo Botryosphaeria ribis (Dothyorella sp.), que ataca principalmente a região apical da planta, causa lesões que podem chegar a anelar e provocar a quebra do ponteiro ou o secamento da planta. Este trabalho teve por objetivo avaliar métodos de controle químico e por extratos vegetais; estudar a dinâmica espacial de foco; a veiculação do patógeno pelas sementes e realizar a análise de perdas e danos. O teste "in vitro" dos fungicidas constou de oito tratamentos, com 4 doses cada, havendo cinco repetições para cada tratamento. A avaliação foi feita através de medição diária do crescimento radial do micélio em centímetros. O controle químico apresentou cinco tratamentos e três métodos de aplicação, num esquema fatorial 5x3, com quatro repetições. Foram feitas quatro aplicações, com intervalo de 15 dias. Simultaneamente foram feitas avaliações seguindo uma escala de notas de 1 a 6. O teste "in vitro" dos extratos vegetais constou de cinco tratamentos e quatro concentrações: 5, 10, 15 e 20%, em esquema fatorial 5x4 com três repetições. A avaliação foi feita através de medição diária do crescimento radial do micélio em centímetros. No teste com mudas foram utilizadas duas procedências de sementes, dois modos de aplicação (preventivo e convencional) e quatro tratamentos, sendo dois extratos, álcool e água, com oito repetições. A inoculação do patógeno foi feita no caule das mudas. Foram realizadas aplicações dos produtos e avaliações semanais. A avaliação foi feita por contagem de plantas doentes. Para a análise da dinâmica e estrutura de focos foram gerados 19 mapas com a distribuição espacial de plantas com sintomas de seca de ponteiro, provenientes de áreas de Botucatu e de Pratânia/SP. A partir dos mapas foram calculados número de focos, número e percentagem de focos unitários, índice... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Tip drought is caused by Botryosphaeria ribis (Dothyorella sp.) Which attacks mainly the apical region of the plant and causes damage that can ring and cause the breakdown of pointer or a drying plant. This study aimed to evaluate methods of disease control and plant extracts, the spatial dynamics of focus, pathogen association with seeds and analysis of damages. The test in vitro fungicide consisted of eight treatments, with four dose and five replications. The evaluation was done by measuring daily radial growth of mycelium in centimeters. The chemical control had five treatments and three methods of application: brushed, pruned and powdered, in a 5x3 factorial design with four replications. Four applications were made with an interval of 15 days. At the same time were evaluated following a scale from 1 to 6. The test in vitro of plant extracts consisted of five treatments: extracts of a thousand leaves, melon sao caetano, eucalyptus, alcohol and control and four concentrations: 5, 10, 15 and 20%, factorial 5x4 com three replications. The extracts and the alcohol were mixed to the culture medium previously autoclaved, they were placed in Petri dishes and after hardening of the medium was placed a disc of the fungus and the plates were kept in BOD at ± 26 ° C for four days. The evaluation was done by measuring daily radial growth of mycelium in centimeters. In the test plants were used with two origins, two modes of aplication (preventive and conventional) and four treatments: extract of melon sao caetano, Corymbia citriodora extract, alcohol and water, a fatorial design 2 x 2 x 4 and eight repetitions. The inoculation was made in the stem of seedlings. Products applications and evaluations were made weekly. The evaluation was done by counting the diseased plants. For the analysis of the dynamics and structure of foci were generated 19 maps with the spatial distribution... (Complete abstract click electronic access below) / Doutor

Please read the Summary in the section 03chapter3 of this document / Dissertation (MSc)--University of Pretoria, 2005. / Plant Science / Unrestricted

The South African commercial forest industry is almost exclusively reliant on plantations of exotic trees, of which Eucalyptus spp. make up almost 50 %. Botryosphaeria spp. are important canker pathogens in these Eucalyptus plantations in South Africa. However, exotic plantations and their pathogens cannot be viewed separately from the related native flora. This study showed the importance of extending our knowledge on pathogens that occur on related native and exotic hosts, and which can pose a threat by cross infection between these host groups. In Chapter 1, a review of the literature concerning Botryosphaeria spp. that occur on Eucalyptus in its native range and exotic plantations is presented. It is clearly shown that Botryosphaeria spp. are important pathogens on Eucalyptus in exotic plantations worldwide, causing various symptoms on this host. Botryosphaeria spp. are also important canker pathogens in Eucalyptus plantations in South Africa. Traditional identification of this group of fungi, based on morphological characteristics, led to much confusion about their identity. However, in recent studies morphological characteristics were combined with DNA sequence data to distinguish and identify these fungi. Based on these data a few revisions have been done and new Botryosphaeria spp. were described on Eucalyptus. Botryosphaeria spp. recognised as pathogens on Eucalyptus in South Africa include B. dothidea, B. parva and B. eucalyptorum. Future studies should be focused on correct identification of Botryosphaeria spp. that occur on Eucalyptus, which is the first step towards preventing the spread of this group of pathogens and developing management strategies to control disease outbreaks. During the study on Botryosphaeria spp. on Syzygium cordatum, isolates of two Botryosphaeria spp. appeared to be undescribed. One of the undescribed species was represented by only one isolate and it was not named. The other species was described as the new Botryosphaeria anamorph within Lasiodiplodia, namely L. gonubiensis. This species grows endophytically on native S. cordatum in South Africa and is the first species in Lasiodiplodia to be found on native trees in the country. Identification of the new species was based on conidial and cultural morphology and DNA sequence data of the rDNA internal transcribed spacers, ITS1 and ITS2. Identification and description of L. gonubiensis is presented and discussed in Chapter 2. In total nine Botryosphaeria spp. were isolated from native Syzygium cordatum in South Africa. These include B. parva, B. ribis, B. lutea, B. australis, B. rhodina, B. dothidea, Fusicoccum mangiferum, Lasiodiplodia gonubiensis and an unknown Botryosphaeria sp. The isolates related to B. ribis, B. parva and F. mangiferum were the most abundant, while only one isolate represented B. dothidea. Species were identified based on morphological characteristics of their anamorphs combined with ITS rDNA sequence data. Some species, such as B. parva and B. ribis, could not be distinguished based on morphology or ITS rDNA data. A PCR-RFLP fingerprinting technique was, therefore, used to distinguish isolates of these two species. Once again this technique has proven useful and reliable in identification of Botryosphaeria isolates, including cryptic species. However, isolates of closely related B. lutea and B. australis could not be distinguished using this technique. It could be of interest to develop PCR-RFLP identification system that could be used in identification of the latter species. Identification and characterization of Botryosphaeria spp. are presented in Chapter 3. Isolates of all Botryosphaeria spp., obtained from native Syzygium cordatum in this study, caused lesions on the stems of Eucalyptus camaldulensis and S. cordatum in trials conducted under greenhouse conditions. Except for Fusicoccum mangiferum, all the other Botryosphaeria spp. were more pathogenic on Eucalyptus than on S. cordatum. The most pathogenic species on Eucalyptus were B. rhodina, B. ribis and B. lutea, whileF. mangiferum and B. ribis were the most pathogenic on S. cordatum. Botryosphaeria dothidea and L. gonubiensis were the least pathogenic on both hosts. The results obtained from this trial clearly show that Botryosphaeria spp. on S. cordatum pose a potential threat to exotic Eucalyptus plantations. Future study should be conducted under field conditions to evaluate data obtained in greenhouse trials. These results were presented and discussed in Chapter 4. The results presented in this study provide the first detailed information on Botryosphaeria spp. on the native Myrtaceae in South Africa. Most of the species isolated from Syzygium cordatum are not known on Eucalyptus in the country. All of the Botryosphaeria spp. obtained in this study are pathogenic to Eucalyptus, and thus pose a threat to this host. Large number of B. ribis, B. parva and F. mangiferum isolates obtained from the native S. cordatum could imply their origin in this region. Further sampling is needed on myrtaceous trees native to the Southern African region, as well as on Eucalyptus. Population studies on the most abundant and most pathogenic Botryosphaeria spp., should provide more information on the movement and origin of these pathogens. The results from this study also highlights the need for quarantine measures to avoid the introduction of new Botryosphaeria spp. or new strains that can be more pathogenic to either native or cultivated plants. Please cite as follows Pavlic, D 2004, Botryosphaeria species on native South African Syzygium cordatum and their potential threat to Eucalyptus , MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02062006-112938/ > / Dissertation (MSc)--University of Pretoria, 2007. / Microbiology and Plant Pathology / MSc / Unrestricted

Please read the abstract (preface) in the section 00front of this document / Dissertation (MSc)--University of Pretoria, 2002. / Microbiology and Plant Pathology / Unrestricted

The mango (Mangifera indica L.) is an appealing subtropical fresh fruit with a pleasant flavor and taste, high nutritional value, beneficial medicinal properties and various processing options. However, as is the case with most subtropical fruit, it is a sensitive commodity, prone to losses postharvestly. The South African mango industry is highly dependent on a hot water and cold prochloraz dip treatment, to control postharvest anthracnose and soft brown rot on fruit destined for export. However, negatve public perceptions of synthetic fungicides and its use on fresh produce for disease control has been increasing in major export markets such as the European Union. This growing concern from a public point of view is forcing industry to consider more environmentally acceptable methods to maintain quality of mangoes during extended export periods. ‘Tommy Atkins’ and ‘Kent’ mangoes either uninoculated or artificially inoculated with Colletotrichum gloesporioiedes, Botryosphaeria parva or sterile agar, were used to evaluate softer, greener alternatives, in this study. Fruit were subjected to either a hot, Bacillus amyloliquefaciens (PPCB004) containing dip treatment for two minutes or a 24 hour 1-methylcyclopropene (1-MCP) gas treatment at 16 ºC or no treatment. Fruit were then stored at 10 ºC under either 5% O2 and 5% CO2 (CA-1) or 3% O2 and 8% CO2 (CA-2) controlled atmospheres (CA) for 18 days and allowed to ripen for five days at 25 ºC. Similarly, uninoculated or artificially inoculated fruit subjected to B. amyloliquefaciens, 1-MCP or a combination of the two treatments was stored at 10 ºC for 18 days under conventional storage. ‘Tommy Atkins’ fruit were packed into bags made from four different film types, untreated or after being subjected to a cold B. amyloliquefaciens dip treatment and stored for 23 days at 10 ºC. Overall, ‘Kent’ fruit were more susceptible to anthracnose and SBR after artificial inoculation. In vivo inoculated ‘Tommy Atkins’ fruit, storage under CA-1 gave the best control of soft brown rot whilst CA-2 storage gave the best control of anthracnose. For quality retention no definite conclusion could be made for both cultivars after CA storage or the combination of 1-MCP pre-treatment and CA storage. The combination of 1-MCP pre-treatment and B. amyloliquefaciens maintained the quality of ‘Kent’ mangoes under conventional storage the best. Anthracnose severity on both cultivars was reduced with 1-MCP treated fruit combined with the biocontrol pre-treatment. Modified atmosphere packaging in this study was found to be ineffective in maintaining quality of mangoes. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2011. / Microbiology and Plant Pathology / unrestricted