<i>Sclerotinia minor</i> Jagger is a fungal pathogen of cultivated peanut (<i>Arachis hypogaea</i> L.) that can cause crop losses in excess of 50%. Fungicides are not completely effective at controlling the disease and can cost up to $311 per hectare for three applications. The ability to produce oxalic acid is necessary for the pathogenicity of some <i>Sclerotinia</i> spp. With little to no naturally occurring resistance to Sclerotinia blight in <i>Arachis</i> spp., a biotechnological approach was used to confer resistance to the disease. Peanut plants were transformed with a gene from barley encoding oxalate oxidase, an enzyme that degrades oxalic acid. Transformed peanuts showed resistance to S. minor and increased yields under disease pressure compared to the parental lines. Before the resistant varieties can be marketed, they must be reviewed and approved by the governmental regulatory system. Responsibility for regulation of transgenic plants in the U.S. is shared among the U.S. Department of Agriculture (USDA) through the Animal and Plant Health Inspection Service (APHIS), the Food and Drug Administration (FDA), and the Environmental Protection Agency (EPA). These agencies require several different data sets including molecular characterization and field studies before each transformation event can be commercialized. This project was designed to characterize three different transformation events, N70, P39 and W171. Molecular characterization included determination of insertion number, copy number, intactness of the expression cassette and stable inheritance of the transgene. N70 was found to have two insertions and two copies while W171 had one insertion with one copy. The P39 event has two insertions and two or more copies. Each of the three events was stable over multiple generations. Phenotypic comparisons of each transgenic line to the parent cultivar were carried out in field studies. Characteristics such as oxalate oxidase expression, yield and quality, hay quality, disease occurrence, aflatoxin content and plant height were assessed. Transgenic peanuts showed few differences from the parent cultivar other than resistance to Sclerotinia blight and yield under disease pressure. Outcrossing studies were completed to determine the rate and distance of cross pollination. Outcrossing rates in N70, P39 and W171 were less than 2.5% and occurred up to 19 rows or 17.4 m from the nearest transgenic row. The molecular characterization and field performance of N70, P39 and W171 have been assembled into a document to petition APHIS for determination of non-regulated status. / Master of Science in Life Sciences

Made available in DSpace on 2014-07-29T15:16:31Z (GMT). No. of bitstreams: 1 Lucas Breseghelo do Nascimento.pdf: 1084518 bytes, checksum: 405ebc26f906f0428e9438063c66ee44 (MD5) Previous issue date: 2010-08-31 / The fungus Sclerotinia sclerotiorum is among the most successful pathogens, omnivores, and without specific hosts, is considered one of the most important fungal pathogens in the world. Is distributed in all producing regions, temperate, subtropical or tropical. The fungus produces resistant structures called sclerotia on the surface and within tissues colonized, they returned to the soil with crop residues and are responsible for the survival of the fungus in the same area for up to eight years. The objectives of this study were to quantify the variability within and between populations of the fungus S. sclerotiorum in bean and soybean crops in different producing places of those varieties. 46 isolates were collected of S. sclerotiorum in six locals of grain production in different regions of Brazil. The sites chosen were Monte Carmelo-MG, Formosa-GO, Lucas do Rio Verde-MT, Montividiu-GO, Londrina, PR and Santo Antonio de Goiás-GO. All areas of the original host of the gathering was the bean with the exception of Londrina-PR in which the host was soybeans. A population study of the fungus through RAPD markers using 13 primers was carried out for the analysis of genetic variability of the fungus. In parallel, tests were also made for the the Mycelial compatibility groups among isolates and test production of hydrolytic enzymes. The statistical analysis was performed using the Arlequin software, which indicated variability among populations of 16.94% and 83.06% within populations. Were found 10 mycelial compatibility groups without specific populations .Enzyme activities performed indicated significant differences within the populations of all enzymes, a comparison between populations also showed significant differences among populations in polygalacturonases, 1,3-&#946;-glucanase and xylanase. The results indicate a high level of variability within populations and low variability among populations / O fungo Sclerotinia sclerotiorum está entre os fitopatógenos mais bem sucedidos, onívoros e sem hospedeiros definido, é considerado um dos patógenos fúngicos mais importantes no mundo. Está distribuído em todas as regiões produtoras, sejam elas temperadas, subtropicais ou tropicais. O fungo produz estruturas de resistência denominadas escleródios, na superfície e no interior dos tecidos colonizados. Estes retornam ao solo com os resíduos da cultura e são responsáveis pela sobrevivência do fungo na mesma área por até 8 anos. Os objetivos desse trabalho foram quantificar a variabilidade intra e inter populacional do fungo S. sclerotiorum em culturas de feijão e soja de diferentes localidades produtoras dessas espécies. Para isso foram coletados 46 isolados de S. sclerotiorum de seis locais de produção de grãos em diferentes regiões do Brasil. Os locais escolhidos foram Monte Carmelo-MG, Formosa-GO, Lucas do Rio Verde-MT, Montividiu-GO, Londrina-PR e Santo Antonio de Goiás-GO em todas as áreas o hospedeiro de origem da coleta foi o feijoeiro, com exceção de Londrina-PR, na qual o hospedeiro foi soja. Foi feito um estudo populacional do fungo através de marcadores do tipo RAPD com a utilização de 13 primers para a análise da variabilidade genética do fungo. Paralelamente também foram feitos testes para a formação de grupo de compatibilidade micelial entre os isolados e testes de produção de enzimas hidrolíticas. A análise estatística dos dados se deu através do programa Arlequin, o qual indicou variabilidade de 16,94% entre populações e 83,06% dentro de populações. Foram formados 10 grupos de compatibilidade micelial sem especificidade de populações. As atividades enzimáticas realizadas indicaram diferenças significativas dentro de populações de todas as enzimas. A comparação entre populações também indicou diferenças significativas entre populações nas enzimas poligalacturonases, 1,3-&#946;-glucanase e xilanase. Os resultados indicaram baixo nível de variabilidade entre populações e alta variabilidade dentre as populações.

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-03T12:52:10Z No. of bitstreams: 2 Dissertação - Lucas Breseghelo do Nascimento - 2010.pdf: 1202324 bytes, checksum: 56c8aee88b007b5162aa73419f965d0d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-03-04T11:34:37Z (GMT) No. of bitstreams: 2 Dissertação - Lucas Breseghelo do Nascimento - 2010.pdf: 1202324 bytes, checksum: 56c8aee88b007b5162aa73419f965d0d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-04T11:34:37Z (GMT). No. of bitstreams: 2 Dissertação - Lucas Breseghelo do Nascimento - 2010.pdf: 1202324 bytes, checksum: 56c8aee88b007b5162aa73419f965d0d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2010-08-31 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The fungus Sclerotinia sclerotiorum is among the most successful pathogens, omnivores, and without specific hosts, is considered one of the most important fungal pathogens in the world. Is distributed in all producing regions, temperate, subtropical or tropical. The fungus produces resistant structures called sclerotia on the surface and within tissues colonized, they returned to the soil with crop residues and are responsible for the survival of the fungus in the same area for up to eight years. The objectives of this study were to quantify the variability within and between populations of the fungus S. sclerotiorum in bean and soybean crops in different producing places of those varieties. 46 isolates were collected of S. sclerotiorum in six locals of grain production in different regions of Brazil. The sites chosen were Monte Carmelo-MG, Formosa-GO, Lucas do Rio Verde-MT, Montividiu-GO, Londrina, PR and Santo Antonio de Goiás-GO. All areas of the original host of the gathering was the bean with the exception of Londrina-PR in which the host was soybeans. A population study of the fungus through RAPD markers using 13 primers was carried out for the analysis of genetic variability of the fungus. In parallel, tests were also made for the the Mycelial compatibility groups among isolates and test production of hydrolytic enzymes. The statistical analysis was performed using the Arlequin software, which indicated variability among populations of 16.94% and 83.06% within populations. Were found 10 mycelial compatibility groups without specific populations .Enzyme activities performed indicated significant differences within the populations of all enzymes, a comparison between populations also showed significant differences among populations in polygalacturonases, 1,3-β-glucanase and xylanase. The results indicate a high level of variability within populations and low variability among populations. / O fungo Sclerotinia sclerotiorum está entre os fitopatógenos mais bem sucedidos, onívoros e sem hospedeiros definido, é considerado um dos patógenos fúngicos mais importantes no mundo. Está distribuído em todas as regiões produtoras, sejam elas temperadas, subtropicais ou tropicais. O fungo produz estruturas de resistência denominadas escleródios, na superfície e no interior dos tecidos colonizados. Estes retornam ao solo com os resíduos da cultura e são responsáveis pela sobrevivência do fungo na mesma área por até 8 anos. Os objetivos desse trabalho foram quantificar a variabilidade intra e inter populacional do fungo S. sclerotiorum em culturas de feijão e soja de diferentes localidades produtoras dessas espécies. Para isso foram coletados 46 isolados de S. sclerotiorum de seis locais de produção de grãos em diferentes regiões do Brasil. Os locais escolhidos foram Monte Carmelo-MG, Formosa-GO, Lucas do Rio Verde-MT, Montividiu-GO, Londrina-PR e Santo Antonio de Goiás-GO em todas as áreas o hospedeiro de origem da coleta foi o feijoeiro, com exceção de Londrina-PR, na qual o hospedeiro foi soja. Foi feito um estudo populacional do fungo através de marcadores do tipo RAPD com a utilização de 13 primers para a análise da variabilidade genética do fungo. Paralelamente também foram feitos testes para a formação de grupo de compatibilidade micelial entre os isolados e testes de produção de enzimas hidrolíticas. A análise estatística dos dados se deu através do programa Arlequin, o qual indicou variabilidade de 16,94% entre populações e 83,06% dentro de populações. Foram formados 10 grupos de compatibilidade micelial sem especificidade de populações. As atividades enzimáticas realizadas indicaram diferenças significativas dentro de populações de todas as enzimas. A comparação entre populações também indicou diferenças significativas entre populações nas enzimas poligalacturonases, 1,3-β-glucanase e xilanase. Os resultados indicaram baixo nível de variabilidade entre populações e alta variabilidade dentre as populações.

Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-06-02T12:47:54Z No. of bitstreams: 1 MarianaRochaMaximianoDissertacaoParcial2015.pdf: 459398 bytes, checksum: b2185a3a3375dbb7ac1ed82fc658146b (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-06-02T12:48:21Z (GMT) No. of bitstreams: 1 MarianaRochaMaximianoDissertacaoParcial2015.pdf: 459398 bytes, checksum: b2185a3a3375dbb7ac1ed82fc658146b (MD5) / Made available in DSpace on 2017-06-02T12:48:21Z (GMT). No. of bitstreams: 1 MarianaRochaMaximianoDissertacaoParcial2015.pdf: 459398 bytes, checksum: b2185a3a3375dbb7ac1ed82fc658146b (MD5) Previous issue date: 2015-06-18 / Sclerotinia sclerotiorum, the causal agent of white mold, is a plant pathogenic fungus that has a characteristic feature, production of sclerotia, resistance structures that can be viable for up to 10 years in the soil, with ability to initiate a new cycle of infection under favorable conditions. The disease control methods are based on integrated management practices, including biological and chemical control. The proteomic study of this interaction may be a strategy for studying this pathosystem, however, the small amount of mycelium produced during the infectious process in vivo greatly limits the study of this pathosystem using this strategy. The main goals of this work were the development and validation of a culture medium that would partially mimic the host and allow the production of large amounts of micelium for in vitro studies of this pathosystem. For this purpose, a protocol was established for the production of culture media prepared with leaf extract of the hosts. These media were inoculated with sclerotia of the monosporic isolate SS 200 of S. sclerotiorum and the differential expression of effectors and candidate effectors of virulence of the fungus was evaluated by qPCR. The results showed that a large amount of micelia grew in the media and effector genes and candidate effector genes were induced in these media. These results indicate that the proposed culture media can be used to study the in vitro interaction between S. sclerotiorum and several plant hosts and that they can be useful especially in proteomic studies. / Sclerotinia sclerotiorum, agente causal do mofo branco, ?? um fungo fitopatog??nico que possui uma caracter??stica marcante, a produ????o de escler??dios, estruturas de resist??ncia que podem ser vi??veis por at?? 10 anos no solo, com capacidade de iniciar um novo ciclo de infec????o em condi????es favor??veis. Os m??todos de controle da doen??a baseiam-se em pr??ticas de manejo integrado, incluindo controle biol??gico e qu??mico. O estudo prote??mico desta intera????o pode ser uma estrat??gia para o estudo deste patossistema, entretanto, a pequena quantidade de mic??lio produzido pelo pat??geno durante o processo infeccioso in vivo limita bastante o estudo deste patossistema utilizando esta estrat??gia. Os objetivos deste trabalho foram o desenvolvimento e valida????o de um meio de cultura que mimetizasse parcialmente o hospedeiro e permitisse a produ????o de grande quantidade de massa micelial para estudos in vitro desse patossistema. Para tal, foi estabelecido um protocolo para a produ????o de meios de cultura, preparados a partir de extratos foliares dos hospedeiros. Estes meios foram inoculados com escler??dios do isolado monosp??rico de S. sclerotiorum SS 200 e a express??o diferencial de genes efetores e candidatos a efetores de virul??ncia do fungo foi avaliada por qPCR. Os resultados mostraram que em todos os meios testados houve crescimento de grande quantidade de massa micelial e que os meios foram capazes de induzir a express??o de genes efetores e candidatos a efetores. Portanto, os resultados indicam que os meios propostos podem ser usados no estudo da intera????o in vitro de S. sclerotiorum com v??rios hospedeiros, especialmente em estudos prote??micos.

No description available.

No description available.

Bibliography: leaves 128-136.

The fungal pathogen S. sclerotiorum (Sclerotinia sclerotiorum) impacts production and yield in one of Canada’s number one crops, canola (Brassica napus). Unfortunately, few cultivars show any tolerance to this devastating fungal pathogen. Thus, understanding how the plant responds to this aggressive fungus at the cellular level will facilitate the identification of genes and gene products responsible for improved plant performance. While our understanding of the host pathogen interaction is becoming clearer, there is remarkably little information available for Sclerotinia, especially its pathogenicity in canola. Moreover, we know nothing about how this interaction is specified at the cellular, physiological or molecular level directly at the site of infection in mature leaves following petal inoculation. Thus, we compared differences in plant structure, antioxidant response, and genes involved in the salicylic acid, jasmonic acid and ethylene defense pathways in a susceptible cultivar, Westar, and a previously described tolerant cultivar, Zhongyou821 (ZY821). Our data showed that at the cellular level, ZY821 was able to suppress the Sclerotinia penetration. The ascorbate-glutathione pathway and resistant signaling pathways were all associated with the canola defense response to S. sclerotiorum, while stronger antioxidant and signaling pathways responses were observed in ZY821 leaves at the site of infection. Also, transcriptional regulators not previously associated with plant defense in the Arabidopsis- S. sclerotiorum pathosystem were identified through bioinformatics approaches. By comparing plant susceptibility to S. sclerotiorum between Arabidopsis wild type and seven loss-of-function mutants, I found transcription factor JAM2 might be involved in plant tolerance to S. sclerotiorum. / October 2014

Sclerotinia sclerotiorum is a pathogen of crops grown in the muck soil regions of Quebec. Soil baiting tests indicated that the sclerotia of S. sclerotiorum are attacked and destroyed by the larvae of Bradysia coprophila and mycoparasites. Sclerotia with rinds partially damaged by the larvae were found to be more susceptible to mycoparasitism by Trichoderma viride. Increasing the organic matter content and porosity of soils resulted in increased damage to sclerotia when larvae were present. Studies conducted to determine if larvae could be reared on diets of various fungi and plant tissue showed that mycelia and sclerotia of S. sclerotiorum were the most successful food sources, followed by mycelia and sclerotia of Botrytis porri and Rhizoctonia solani. Adults produced on mycelia and sclerotia of Sclerotinia minor, Fusarium solani f. sp. pisi, and Botrytis cinerea seldom were fertile. Larvae generally failed to survive when reared on cultures of Trichoderma viride. Larval development occurred on all plants inoculated with the above pathogens but failed to occur on noninoculated healthy plants. Salivary gland secretions of the larvae were found to inhibit the germination of sclerotia. Analyses of the secretion determined that it contains 4.3% protein and had chitinase activity. Mechanically damaged and undamaged sclerotia exhibited an increase in eruptive mycelial germination when treated with 1.5 $ mu$g ml$ sp{-1}$ chitinase but germination decreased at 50, 100 and 150 $ mu$g ml$ sp{-1}$ chitinase concentrations. Noneruptive mycelial germination and carpogenic germination occurred when sclerotia were treated with acetate buffer and distilled water.

Control of Taraxacum officinale (dandelion) and other broadleaf weeds in turfgrass has been readily achieved with phenoxy herbicides, but the herbicide option has been revoked in many regions, necessitating alternative weed control strategies. One biological alternative is Sclerotinia minor, an Ascomycete fungus. The impact of S. minor on broadleaf weed dynamics and biotic interactions were studied in a turfgrass environment. The goal was to maximize effectiveness of a S. minor formulation as a biocontrol of dandelion using an ecological approach. S. minor efficacy was not affected by turf microenvironments and was similarly efficacious with spring or fall application. All accessions from a worldwide collection of dandelion and 32 turfgrass broadleaf species were susceptible to S. minor. Biocontrol efficacy was inversely correlated with dandelion age, but efficacy on all ages was enhanced in the presence of grass competition. When combined with regular mowing at 7-10 cm, the S. minor suppressive effect on dandelion was similar to the herbicide effect, particularly in the following season. Weed suppression was less with close mowing at 3-5 cm due to increased dandelion seedling recruitment. While spring herbicide application was effective to suppress dandelion population, the S. minor treatment has no residual activity, necessitating a second application to suppress seedling recruits. Root regrowth after S. minor infection was minimal and was further reduced in superior quality turf after season-long mowing, and after spring applications. S. minor infected dandelion seeds, reduced the dandelion seedbank, and reduced dandelion seedling emergence by 98%. S. minor did not affect the emergence or the total biomass of cool season temperate turfgrass species. Turfgrass quality was improved following S. minor application and populations of other broadleaf weeds were also controlled by S. minor. Understanding the biotic interactions within the turfgrass environment has rewardingly lead to successful integration of the S.minor biocontrol with the common management tools of mowing and over-seeding to achieve excellent control of dandelion and a healthy thriving turf.