Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xiii, 118 p.; also includes graphics Includes bibliographical references (p. 114-118). Available online via OhioLINK's ETD Center

Made available in DSpace on 2015-03-26T13:23:45Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1323433 bytes, checksum: bee384a32e57198c4e07d87d837b034e (MD5) Previous issue date: 2012-05-25 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Fungal diseases of postharvest, mainly anthracnose, are one of the causes of papaya depreciation with losses in trading. The process normally used for this disease control in postharvest includes hydrothermal treatment at 49 °C for 20 minutes, followed by cooling for the same period, besides the application of fungicides. Disadvantages linked to conventional treatments lead to search for new methods to control postharvest anthracnose in papaya. One alternative is ozone gas (O3) usage, for being a strong oxidizing and antimicrobial agent, which can be generated on site by an electrical discharge, dismissing the need for handling, storage, or disposal of packaging. This study aimed to evaluate the effectiveness of ozone dissolved in water to control anthracnose in papaya and check the influence of this treatment on these fruits physical and chemical characteristics. Papaya (Carica papaya L.) Golden cultivar was used, harvested at maturity stage 1, with up to 15% yellow color. To evaluate the ozone effect in controlling anthracnose, fruits were inoculated with spore suspension of Colletotrichum gloeosporioides and C. magna at a concentration of 2.3 x 106 CFU mL-1. Subsequently, fruits ozonation was performed in tank with water containing dissolved ozone at a concentration of 0.8 mg L-1 for periods of 40, 80, 120, and 160 minutes. Non-ozonated fruits were used as control. After this process, the fruits were stored in chambers at 11 °C and 80 to 85% RH for 15 days. Analyzes were performed in this period in the first and 15th days. Subsequently, the chamber temperature was changed to 25 °C and analyzes was made on the 17°, 19°, 21°, and 23° days of storage. Data were subjected to variance analysis using SAEG (SAEG, 2007) statistical software. The comparison of analysis mean values of the ozonated or non-ozonated fruit stored for zero and 15 days was performed by the F test at 5% probability. In the second step, fruits stored at 25 °C for eight days were analyzed from the 15th day. Split plot scheme was made and in the parcels there were five periods of exposure (0, 40, 80, 120, and 160 minutes) to Ozone dissolved in water; and in subplots there were five periods of fruits storage (0, 2, 4, 6, and 8 days, except for CO2 production, that in subplot there were four storage periods, from the second day) in a completely randomized design (CRD) with two replicates, except percentage of injured area, with three replicates. Analyzes were of percentage of injured area, CO2 production, fresh mass loss, titratable acidity, soluble solids, skin color, vitamin C content, pulp firmness, and pH. During storage at 11 °C, there was no significant increase in lesioned area by anthracnose. The papayas showed increased respiratory rate with a trend towards smaller increase for those exposed to ozone. The firmness decreased during this period. Values of Hue° decreased and values of Chroma and Color Difference increased. Fruit fresh mass suffered a decrease and parameters suffered titratable acidity, soluble solids, and vitamin C content; pH showed no change during this period. During storage at 25 °C, lowest percentage of lesioned area in fruits treated with ozone was recorded in comparison to untreated fruits. The fruits exposed to ozone dissolved in water also showed less loss of firmness and lower respiration rate during storage. The color parameters (Chroma, Hue°, and Color Difference), pH, soluble solids, and titratable acidity of ozonated papayas did not differ from those observed in fruits exposed to ozone dissolved in water. It can be concluded that the application of ozone dissolved in water at a concentration of 0.8 mg L-1 for up to 160 minutes is efficient in reducing the severity of anthracnose in postharvest of papaya Golden cultivar without, however, adversely affecting fruits quality. / As doenças fúngicas de pós-colheita, principalmente a antracnose, constituem uma das causas de depreciação do mamão, com perdas na comercialização. O processo normalmente utilizado para controle dessa doença em pós-colheita inclui tratamento hidrotérmico dos frutos a 49 °C durante 20 min, com posterior resfriamento por igual período, além da aplicação de fungicidas. As desvantagens associadas aos tratamentos convencionais tornam necessária a busca de novos métodos de controle da antracnose na pós-colheita do mamão. Uma das alternativas é a utilização do gás ozônio (O3), por se tratar de forte agente oxidante e antimicrobiano, que pode ser gerado no local por meio de uma descarga elétrica, descartando a necessidade de manipulação, armazenamento ou eliminação de embalagens. O presente trabalho teve como objetivo avaliar a eficácia do ozônio dissolvido em água para controle de antracnose em mamões, bem como verificar a influência desse tratamento nas características físs e químicas dos frutos. Foram utilizados mamões (Carica papaya L.) Golden , colhidos no estádio de maturação 1, com até 15% de cor da casca amarela. Para a avaliação do efeito do ozônio no controle de antracnose, os frutos foram inoculados com suspensão de conídios de Colletotrichum gloesporioides e C. magna, na concentração de 2,3 x 106 UFC mL-1. Posteriormente procedeu-se à ozonização dos frutos em tanque com água contendo ozônio dissolvido na concentração de 0,8 mg L-1, pelos períodos de 40, 80, 120 e 160 min. Como controle foram utilizados frutos não ozonizados. Após esse processo, os frutos foram armazenados em câmaras climáticas a 11 °C e 80 a 85% UR por 15 dias. Foram feitas análises nesse período no primeiro e no 15° dia. Posteriormente, a temperatura da câmara foi modificada para 25 °C, sendo feitas análises nos 17°, 19°, 21° e 23° dias de armazenamento. Foram analisados o percentual de área lesionada, produção de CO2, perda de massa fresca, acidez titulável, sólidos solúveis, cor da casca, teor de vitamina C, firmeza da polpa e pH. Durante o armazenamento a 11 °C, não houve aumento significativo de área lesionada por antracnose. Os mamões apresentaram aumento da taxa respiratória, com uma tendência de menor aumento para aqueles expostos ao ozônio. A firmeza da polpa apresentou redução nesse período. Os valores do ângulo Hue (h°) apresentaram decréscimo e os valores de Croma e Diferença de cor aumentaram. A massa fresca dos frutos sofreu decréscimo e os parâmetros acidez titulável, sólidos solúveis, teor de vitamina C e pH não apresentaram variação nesse período. Durante o armazenamento a 25 °C, foi verificado menor percentual de área lesionada nos frutos tratados com ozônio, em comparação aos não tratados. Os frutos expostos ao ozônio dissolvido na água também apresentaram menor perda de firmeza da polpa e menor taxa respiratória ao longo do armazenamento. Os parâmetros de cor (Croma, Hue° e diferença de cor), pH, sólidos solúveis e acidez titulável dos mamões ozonizados não diferiram dos observados nos frutos expostos ao ozônio. Pode-se concluir que a aplicação do ozônio dissolvido na água, na concentração de 0,8 mg L-1, por até 160 min, é eficiente na diminuição da severidade de antracnose na pós-colheita de frutos de mamão Golden , sem, entretanto, afetar negativamente a qualidade dos frutos.

Orientador: Antonio Carlos Maringoni / Banca: Silvania Helena Furlan de Oliveira / Banca: Marta Helena Vechiato / Resumo: Colletotrichum lindemuthianum (Sacc. & Magn.) Scrib. e o agente causal da antracnose do feijoeiro (Phaseolus vulgaris L.), doenca fungica de grande importancia para a cultura, pois pode causar perdas de ate 100% na producao, quando sao utilizadas cultivares suscetiveis e sementes infectadas, sob condicoes ambientais favoraveis ao desenvolvimento de epidemias. O presente trabalho objetivou avaliar a sensibilidade in vitro de 20 isolados de Colletotrichum lindemuthianum, provenientes de diferentes regioes do pais, a cinco fungicidas de diferentes principios ativos e algumas misturas (carbendazin, chlorothalonil, tiofanato metilico, chlorothalonil + tiofanato metilico, trifloxystrobin, propiconazol, trifloxystrobin + propiconazol), em cinco diferentes concentracoes (0, 1, 10, 100 e 1000 -Êg.mL-1) adicionados em meio de cultura batata-dextrose-agar (BDA). Os isolados cresceram por sete dias a 25 -C no meio de cultura BDA e apos esse periodo, discos de 0,5 cm de micelio do fungo, foram transferidos para placas de Petri com o meio BDA contendo as diferentes concentracoes de fungicidas. As placas foram incubadas por sete dias a 25 -C, avaliado o crescimento medio do diametro das colonias (em cm) e calculado os valores de porcentagem de inibicao do crescimento micelial dos isolados em relacao ao tratamento testemunha. Os resultados mostraram que para os fungicidas carbendazin e tiofanato metilico, 11 isolados fungicos foram totalmente ou parcialmente inibidos na concentracao de 1 ou 10 -Êg.mL-1. Chlorothalonil mostrou-se menos eficiente que os demais produtos pelo fato de inibir o crescimento micelial de apenas tres isolados na concentracao de 1000 -Êg.mL-1. A mistura de chlorothalonil e tiofanato metilico mostrou a inibicao total do crescimento micelial de quatro isolados a 1 -Êg.mL-1, e, a 1000 -Êg.mL-1, oito isolados mostraram-se sensiveis a mistura desses produtos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Colletotrichum lindemuthianum (Sacc. & Magn.) Scrib. is the causal agent of anthracnose in bean (Phaseolus vulgaris L.). This fungal disease has great importance in the crop, since it may cause yield losses of up to 100% when susceptible cultivars and infected seeds are used under environmental conditions that favor the development of epidemics. The aim of this work was to evaluate the in vitro sensitivity of 20 isolates of Colletotrichum lindemuthianum from different regions of the country, to five fungicides with different active principles and some mixtures (carbendazim, chlorothalonil, methyl thyophanate, chlorothalonil + methyl thyophanate, trifloxystrobin, propiconazole, trifloxystrobin + propiconazole), at five different concentrations (0, 1, 10, 100, and 1000 ìg.mL-1), added to potato-dextrose-agar (PDA) culture medium. The isolates were cultured for seven days at 25 °C in PDA medium, after which 0.5 cm disks of fungal mycelium were transferred to Petri dishes containing PDA medium and the various concentrations of fungicides. The Petri dishes were incubated for seven days at 25 °C. We evaluated the mean growth in diameter of the colonies (in cm) and calculated percentage values for mycelial growth inhibition of the isolates in relation to the control treatment. The results showed that 11 fungal isolates were completely or partially inhibited by the fungicides carbendazim and methyl thyophanate at concentrations of 1 or 10 ìg.mL-1. Chlorothalonil proved less effective than the other products, as it inhibited mycelial growth in only three isolates, at the concentration of 1000 ìg.mL-1. The chlorothalonil and methyl thyophanate mixture showed complete mycelial growth inhibition in four isolates at 1 ìg.mL-1, while eight isolates were sensitive to the mixture of these products at 1000 ìg.mL-1. The propiconazole and trifloxystrobin mixture was the most effective and inhibited growth... (Complete abstract click electronic access below) / Mestre

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O feijÃo-de-corda [Vigna unguiculata (L.) Walp.] pertence à famÃlia Fabaceae e à bastante utilizado na alimentaÃÃo humana como fonte de proteÃnas, carboidratos, vitaminas e minerais. Dentre as principais caracterÃsticas do feijÃo-de-corda, seu elevado conteÃdo proteico e a boa tolerÃncia Ãs condiÃÃes de baixa disponibilidade de Ãgua nos solos, altas temperaturas e relativa tolerÃncia à salinidade, condiÃÃes tÃpicas das regiÃes semi-Ãridas do nordeste do Brasil, sÃo algumas das que podem ser citadas. Entretanto, apesar da considerÃvel capacidade de tolerÃncia Ãs diferentes condiÃÃes de estresses, parte da produtividade do feijÃo-de-corda à ameaÃada pela aÃÃo de diversos fitopatÃgenos, dentre os quais se destacam os fungos como maiores causadores de patologias desta cultura, a exemplo da Antracnose, resultado da infecÃÃo por C. gloeosporioides, caracterizada por manchas marrom-avermelhadas nas nervuras foliares que podem se prolongar por todos os ÃrgÃos da planta hospedeira. Felizmente, o feijÃo-de-corda possui cultivares que apresentam caracterÃsticas diferenciadas de resistÃncia, frente ao C. gloeosporioides, no que concerne à ativaÃÃo das defesas da planta em interaÃÃes ditas incompatÃveis, haja vista que o patÃgeno nÃo consegue deliberar a infecÃÃo. Partindo dessa premissa, à vÃlido mencionar que grande parte dos mecanismos de resistÃncia de plantas aos patÃgenos està relacionada com a expressÃo gÃnica diferencial de proteÃnas que funcionariam como marcadores de defesa em resposta à infecÃÃo. Nesse sentido, esse estudo propÃe a anÃlise proteÃmica diferencial da interaÃÃo incompatÃvel (resistÃncia) entre plantas de feijÃo-de-corda, genÃtipo BR3, e o isolado LPVD-1, do fungo C. gloeosporioides a fim de identificar possÃveis marcadores proteicos determinantes da resistÃncia para esse patossistema. Por meio da utilizaÃÃo da abordagem Eletroforese Bidimensional em combinaÃÃo com Espectrometria de Massas ESI-Q-TOF MS/MS, foram identificadas 118 proteÃnas diferencialmente expressas, considerando proteÃnas superexpressas (102) e subexpressas (16), envolvidas em diversos processos celulares, tais como: Metabolismo energÃtico, fotossÃntese, metabolismo de proteÃnas e Ãcidos nucleicos, resposta ao estresse, transporte celular, homeostase redox, sinalizaÃÃo e defesa, com destaque para expressÃo das proteÃnas PR-10 (relacionada à patogÃnese), Remorina e Ascorbato peroxidase que apresentaram alteraÃÃes significativas em todos os tempos experimentais testados. Esses achados demonstram a complexidade dos mecanismos envolvidos durante a resistÃncia vegetal e auxiliam no direcionamento dos programas de melhoramento genÃtico dessa cultura frente ao ataque de fungos. AlÃm de favorecerem o entendimento das interconexÃes bioquÃmicas e fisiolÃgicas que decorrem da interaÃÃo incompatÃvel planta-fungo. / Cowpea [Vigna unguiculata (L.) Walp.] belongs to the family Fabaceae and is widely used in food as a source of protein, carbohydrates, vitamins and minerals. Among the main features of cowpea, its high protein content and good tolerance to conditions of low water availability in soils, high temperatures and relative tolerance to salinity conditions typical of semi-arid regions of northeastern Brazil, are some of which can be cited. However, despite the considerable capacity of tolerance to different stress conditions, the productivity of cowpea is threatened by the action of various pathogens, among which stand out as major causes of fungal diseases of this crop, the example of Anthracnose as a result of infection by C. gloeosporioides, characterized by reddish-brown spots on the leaf veins that can be extended by all organs of the host plant. Fortunately, the cowpea has cultivars that have different characteristics of resistance against C. gloeosporioides, regarding the activation of plant defenses in incompatible interactions said, given that the pathogen is unable to resolve the infection. From this premise, it is worth mentioning that most of the mechanisms of plant resistance to pathogens is related to the differential gene expression of proteins that act as markers of defense in response to infection. Thus, this study proposes a differential proteomic analysis of the incompatible interaction (resistance) between plants of cowpea genotype BR3, and isolated LPVD-1, the fungus C. gloeosporioides in order to identify potential protein markers for the determinants of this resistance pathossystem. By using the approach 2D-PAGE in addition with mass spectrometry ESI-Q-TOF MS / MS, we have identified 118 differentially expressed proteins, whereas proteins overexpressed (102) and down-expressed (16), involved in various cellular processes, such as : energy metabolism, photosynthesis, protein and nucleic acids metabolism, stress response, cellular transport, redox homeostasis, signaling and defense, with emphasis on expression of PR-10 proteins (pathogenesis-related), remorina and ascorbate peroxidase that had significant alterations at all time points tested. These findings demonstrate the complexity of the mechanisms involved in plant resistance and assist in directing the programs of genetic improvement of this crop against fungal attack. Furthermore, itâs promoting the understanding of the biochemical and physiological interconnections arising from incompatible plant-fungus interaction.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-11-28T14:20:37Z No. of bitstreams: 1 Christiane Almeida da Costa.pdf: 1520147 bytes, checksum: 6d69c020c39cd94f4b4d123eff29fb58 (MD5) / Made available in DSpace on 2016-11-28T14:20:37Z (GMT). No. of bitstreams: 1 Christiane Almeida da Costa.pdf: 1520147 bytes, checksum: 6d69c020c39cd94f4b4d123eff29fb58 (MD5) Previous issue date: 2015-02-25 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Anthracnose caused by Colletotrichum species is the most important disease of chayote in Brazil. In this study, Colletotrichum species associated with anthracnose on fruits and leaves of chayote, from various producing regions in Brazil, were collected and characterized by molecular, morphology and cultural methods. Neighbor-Joining analysis based on sequences of the β-tubulin genomic region (TUB2) of 75 Colletotrichum isolates were analyzed as a first measure of genetic diversity. A subset of 32 isolates were sequenced using the partial sequences of actin (ACT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), calmodulin (CAL) genes and rDNA ITS (ITS) region. Maximum Likelihood (ML) was performed using the concatenated sequences. The multilocus sequence analysis, associated with phenotypic characteristics revealed four previously described species (Colletotrichum brevisporum, C. cliviae, C. fructicola and C. karstii) and two unidentified species, in eight morphotypes. All isolates selected to represent each haplotype, in pathogenicity test were able to induce typical symptoms of anthracnose in chayote but varied in their virulence . All these species are reported for the first time associated with chayote Brazil and worldwide. C. orbiculare is not the causal agent of anthracnose chayote in Brazil. / A antracnose causada por espécies de Colletotrichum é uma das doenças mais importantes da cultura do chuchu no Brasil. Neste estudo, espécies de Colletotrichum associadas à antracnose em frutos e folhas de chuchuzeiro, de algumas regiões produtoras no Brasil, foram coletados e caracterizados a partir de métodos moleculares, morfologia e características culturais. Análise de Neighbor-Joining baseadas em sequências da região genômica da β-tubulina (TUB2), de 75 isolados de Colletotrichum, foram analisadas como uma primeira medida de diversidade genética. Um subgrupo de 32 isolados foram sequenciados usando os genes parcial actina (ACT), gliceraldeído-3-fosfato-desidrogenase (GAPDH), parcial actina (ACT) calmodulina (CAL) e genes rDNA- região ITS (ITS). Máxima verossimilhança (ML) foi realizada utilizando as sequências concatenadas. A análise multilocus das sequências, juntamente com um exame dos caracteres fenotípicos, revelou quatro espécies descritas anteriormente (Colletotrichum brevisporum, C. cliviae, C. fructicola e C. karstii) e duas espécies desconhecidas em oito morfotipos. Todos os isolados selecionados para representar cada haplótipo, no teste de patogenicidade foram capazes de induzir sintomas típicos de antracnose em chuchuzeiro, entretanto com variação em sua virulência. Todas estas espécies são relatadas pela primeira vez em associação ao chuchuzeiro e no Brasil e no mundo. C. orbiculare não é o agente causal da antracnose em chuchuzeiro no Brasil.

<p><i>Colletotrichum sublineolum</i> is the causal agent of sorghum anthracnose, a very common and destructive fungal disease in warm and humid areas, especially in West and Central Africa. Use of host plant resistance is considered as the most important and effective control option for sorghum diseases. To achieve this goal, identification and mapping resistance genes is essential. In this study, we used an isolate of <i>C.</i> <i>sublineolum</i>, CsGL1, to screen our sorghum germplasm and identified a resistant inbred line, P9830. We developed a mapping population from a cross between P9830 and a susceptible line, TAM428, for this research. The population was advanced to the F₆ generation. Progenies were phenotyped at F₂, F₃ and F₆ generations for disease resistance against the pathogen, CsGL1. In the F₂ generation, 460 individuals showed resistance and 149 individuals showed susceptibility to CsGL1. This result fits the 3:1 segregation pattern expected for resistance controlled by a single gene. Bulked segregant analysis with next generation sequencing was used on selected F₆ recombinant inbred lines. A significant peak containing 153 SNPs was observed on the distal end of the long arm of chromosome 8. To verify resistance to CsGL1 was controlled by genes in this region, indel and SNP markers were used between 59.4Mbp and 60.6Mbp on chromosome 8 to fine map the resistance locus. One SNP marker located in the gene <i>Sobic.008G166400</i> co-segregated with resistance, and another two indel markers were discovered to be tightly linked to the resistance locus. These three PCR-based SNP markers would be useful for marker-assisted selection for improving anthracnose resistance against CsGL1. Two candidate genes, <i>Sobic.008G166400</i> and <i>Sobic.008G166550</i>, were found in the locus. Both of the genes encode LRR proteins implicated in plant disease defense response. The identity of DNA sequence between these two candidate genes is 94.1%, possibly the result of tandem duplication. Another possible ortholog in the region is <i>Sobic.008G167500</i>. Quantitative PCR analysis showed that the expression level of <i>Sobic.008G166400</i> didn’t change significantly in a resistant RIL, 17-12 but was induced in a susceptible RIL, 13-31, after CsGL1 infection. In conclusion, we mapped two candidate genes conferring resistant to CsGL1 on chromosome 8, and <i>Sobic.008G166400</i> is more likely of the two to be determined as the gene controlling resistance to CsGL1. </p>

Anthracnose of tomato was first described by Chester in 1891. It has been of economic importance to the growers of canning tomatoes nearly ever since. Anthracnose is cause by Colletptrochum phomoides (sacc.) Chester which appears to have different physiologic and morphologic forms. There is evidence that it is a soil organism but this remains to be definitively proved. The organism has a broad pH range and different isolates show different temperatures opimums but about the same temperature range for growth. The organism does not show the “dual phenomenon” but does sector frequently. Sectors are morphologically different from the parent mycelium and offers an explanation as to the origin of different strains of the organism. / Master of Science

Acidic precipitation reportedly enhances disease severity of dogwood anthracnose (DA) caused by Discula destructiva, on Cornus florida, the flowering dogwood. Seedlings were subjected to acidic fog episodes at pHs 2.5, 3.5, 4.5, and 5.5, using a simulated acidic rain solution. Leaf discs from these and non-treated plants were examined by scanning electron microscopy (SEM). Damage was noted at all pH levels. Discula destructiva conidia may germinate at trichome bases where damage may cause the leaching of nutrients. Also, the difference in stomatal damage may account, in part, for differences in disease susceptibility. Cardinal growth temperatures and response to thermal stress regimes were determined for isolates of Discula destructiva. This information may lead to an understanding of possible climatic barriers, and the thermal treatment of plant material. / Master of Science

L'anthracnose constitue pour plusieurs productions végétales une maladie importante qui engendre des pertes post récoltes considérables. Colletotrichum musae est le responsable de cette maladie chez la banane dessert. L'utilisation d'antimicrobiens naturels comme le système lactoperoxydase (LPS) représente une voie naturelle de lutte intéressante contre l'anthracnose. Dans cette étude, nous avons amélioré le LPS en ajoutant de l'iode dans le système existant ou en substituant le thiocyanate par de l'iode. La substitution du thiocyanate à l'iode a permis d'avoir un effet fongicide du LPS. De plus, d'autres substances comme la lactoferrine, le Bioxeda® et l'huile de Neem ont été étudiées pour leur effet antifongique. Les deux dernières substances ont donné une inhibition supérieure respectivement à 90% et à 40%., tandis qu'il n'y a eu aucun effet de la lactoferrine / Postharvest diseases are a major concern for several plant products, leading to considerable postharvest losses. Colletotrichum musae is responsible for anthracnose and is also involved in crown rot, the two main postharvest diseases of bananas. The use of natural anti-microbial agents such as the lactoperoxidase system (LPS) represents an interesting alternative to the use of fungicides for the control of postharvest diseases of bananas. This study consisted on optimization of the LPS by adding iodide or substituting the thiocyanate by iodide. Moreover, other substances like lactoferrin, Bioxeda® and Neem oil were analyzed for their antifungal effect. The last two compounds gave an inhibition higher than 90% and 40% respectively. No effect of lactoferrin was observed

O objetivo do trabalho foi determinar o efeito da temperatura e período de molhamento no processo de infecção de Colletotrichum gloeosporioides e C. acutatum em goiaba e folhas de citros, respectivamente, além de evidenciar o processo de colonização de C. gloeosporioides. Para determinar o processo de infecção em diferentes combinações de temperatura e períodos de molhamento, suspensões de conídios de C. gloeosporioides foram depositadas em placas de poliestireno e incubadas sob temperaturas de 10, 15, 20, 25, 30, 35 e 40 °C, com período de molhamento de 6, 12, 24, 36 e 48 horas. Para C. acutatum, as placas foram incubadas sob temperaturas de 5, 10, 15, 20, 25, 30 e 35 °C, com períodos de molhamento de 6, 12, 24, 36 e 48 horas. In vivo, suspensões de conídios de C. gloeosporioides foram depositadas na superfície de goiabas que foram incubadas sob temperaturas de 10, 15, 20, 25 e 30 °C e períodos de molhamento de 6, 12 e 24 horas. Folhas de citros foram inoculadas com suspensões de dois isolados de C. acutatum e incubadas sob temperatura de 15, 20, 25 e 30 °C e períodos de molhamento de 12, 24 e 48 horas. Para os estudos do processo de colonização, goiabas com 110 dias após a queda das pétalas foram inoculadas e incubadas a 25 °C e períodos de molhamento de 48, 72, 96 e 120 horas. Posteriormente, frutos com 10, 35, 60 e 85 dias também foram inoculados e incubados a 25 °C por 48 horas. Para visualizar estruturas do tecido vegetal e fenóis, secções de frutos com as diferentes idades foram coradas com azul de toluidina e ACN. As temperaturas ótimas in vitro para germinação de C. gloeosporioides, apressórios formados e melanizados foram, respectivamente, 22,7, 20,6 e 23 °C. Para o isolado KLA-MGG-1 de C. acutatum foi 23,9 °C para germinação e 23,5 °C para formação de apressórios, enquanto para o isolado FSH-CLB-2 foi 21,6 °C para ambas as variáveis. Em goiaba, as temperaturas ótimas para germinação de C. gloeosporioides e formação de apressórios foram 22,4 e 23,3 °C, respectivamente. Em folhas de laranjeira, as temperaturas ótimas para os isolados KLA-MGG-1 e FSH-CLB-2 foram, respectivamente, 24,1 e 24 °C para germinação e 21,2 e 23 °C para formação de apressórios. Para folhas de limoeiro, foram 18,1 °C para germinação e 16,2 °C para formação de apressórios do isolado KLA-MGG-1. Para o isolado FSH-CLB-2, as temperaturas ótimas foram 24,4 e 23,7 °C, respectivamente. A estratégia de colonização de C. gloeosporioides foi intracelular hemibiotrófica. Em amostras com 48 h após a inoculação, foi verificado o peg de penetração. Com 72 horas, observou-se a formação da vesícula de infecção. As hifas foram observadas em amostras com 96 h após inoculação. As mesmas estruturas fúngicas alcançaram as células parenquimáticas com 120 horas após inoculação. O peg de penetração foi observado apenas em frutos com 85 e 110 dias. Estruturas do tecido vegetal e fenóis foram alterados com a idade dos frutos. / The objective of this study was to determine the effect of temperature and the wetness periods in the infection process of Colletotrichum gloeosporioides and C. acutatum in guava and citrus leaves, respectively, besides evidencing the colonization process of C. gloeosporioides. To determine the infection process at different temperature and wetness periods combinations, conidial suspensions of C. gloeosporioides were deposited on polystyrene dishes and incubated at 10, 15, 20, 25, 30, 35 and 40 °C with wetness periods of 6, 12, 24, 36 and 48 h. For C. acutatum, the dishes were incubated at 5, 10, 15, 20, 25, 30 and 35 °C, with wetness periods of 6, 12, 24, 36 and 48 h. In vivo conidial suspensions of C. gloeosporioides were placed on the surface of guavas which were incubated at 10, 15, 20, 25 and 30 °C with wetness periods of 6, 12 and 24 h. The citrus leaves were inoculated with suspensions of two isolates of C. acutatum and incubated at 15, 20, 25 and 30 °C with wetness durations of 12, 24 and 48 h. For the analysis on the colonization process, physiological mature guava fruits were inoculated and incubated at 25 °C with wetness periods of 48, 72, 96 and 120 h. Afterward, fruits with 10, 35, 60 and 85 days were also inoculated and incubated at 25 °C for 48 hours. To visualize the structures of vegetal tissues and phenols, sections of fruits at different ages were colored in toluidine blue and ACN. Optical temperature for conidial germination, appressoria formation and appressoria melanization for C. gloeosporioides were, respectively, 22.7, 20.6 and 23.0 °C. For C. acutatum isolate KLA-MGG-1, they were 23.9 °C for germination and 23.5 °C for appressoria formation and for isolate FSH-CLB-2 it was 21.6 °C for both variable. In guava, the temperatures for germination of C. gloeosporioides and appressoria formation were 22.4 and 23.3 °C, respectively. In leaves of orange trees, the optimal temperatures for the isolates KLA-MGG-1 and FSH-CLB-2 were, respectively, 24.1 and 24 °C for germination and 21.2 and 23 °C for appressoria formation. In leaves of lemon trees, they were 18.1 °C for germination and 16.2 °C for appressorial production of isolate KLA-MGG-1. For isolate FSH-CLB-2, the optimal temperatures were 24.4 and 23.7 °C, respectively. The colonization strategy of C. gloeosporioides was intracellular hemibiotrophic. The penetration peg was verified in samples 48 h after inoculation. After 72 h, it was observed formation of infection vesicle. The hyphae were observed in samples 96 h after inoculation. The same fungal structures reached the parenchymal cells 120 hours after inoculation. The penetration peg was observed only in fruits with 85 and 110 days. Structures of guava tissues and phenols were changed with the fruit aging.