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Among edible mushrooms, Pleurotus eryngii is unique due to its flavor, admirable medicinal and nutritional profiling. Pakistan is an agricultural country diverse in various crops. However, the residues of the horticultural and agronomic crops are wasted without utilization in the food chain. Hence, a study was performed to assess the performance of relatively low-cost, easily available crops residues i.e. cotton, rice, wheat, mustard and water chestnut for yield and nutrition enhancement of Pleurotus eryngii strains P9 (China) and P10 (PSU-USA). The results revealed that morphological attributes i.e. mycelium run, fruit development, yield and biological efficiency were significantly higher by using cotton waste as compared to other substrates. Regarding biochemical attributes i.e. total soluble solids (12.67 °Brix), phenolics (259.6 mg/100g), moisture (92.3%) and ascorbic acid contents (2.9 mg/100ml) were also significantly higher by using cotton waste. Whereas, acidity (0.30%), reducing sugar (7.67%), non-reducing (4.33%) and total sugars contents (12%) were found highest by using mustard straw. Nutrient analysis of substrates showed that nutrient levels were increased after harvesting of crop as compared to before harvesting levels. Overall results revealed that cotton waste and mustard straw are promising substrates for Pleurotus eryngii better growth and have potential in yield and nutrition enhancement. Moreover, P10 strain performed better as compared to P9. Resumo Entre os cogumelos comestíveis, Pleurotus eryngii é único por causa de seu sabor e seu admirável perfil medicinal e nutricional. O Paquistão é um país agrícola com diversas culturas. No entanto, os resíduos das culturas hortícolas e agronômicas são desperdiçados sem aproveitamento na cadeia alimentar. Assim, um estudo foi realizado para avaliar o desempenho de resíduos de culturas com custos relativamente baixos e facilmente disponíveis, ou seja, algodão, arroz, trigo, mostarda e castanha-de-água, para o aumento da produtividade e nutrição de cepas de P. eryngii P9 (China) e P10 (PSU-EUA). Os resultados revelaram que os atributos morfológicos, ou seja, função do micélio, desenvolvimento de frutos, rendimento e eficiência biológica, foram significativamente maiores usando resíduos de algodão em comparação com outros substratos. Em relação aos atributos bioquímicos, ou seja, sólidos solúveis totais (12,67 °Brix), fenólicos (259,6 mg / 100 g), umidade (92,3%) e teores de ácido ascórbico (2,9 mg / 100 ml), também foram significativamente maiores usando resíduos de algodão. Já os teores de acidez (0,30%), açúcares redutores (7,67%), não redutores (4,33%) e açúcares totais (12%) foram os mais elevados na palha de mostarda. A análise de nutrientes dos substratos mostrou que os níveis de nutrientes aumentaram após a colheita da cultura em comparação com os níveis antes da colheita. Os resultados gerais revelaram que os resíduos de algodão e a palha de mostarda são substratos promissores para o melhor crescimento de P. eryngii e têm potencial na melhoria da produtividade e nutrição. Além disso, a cepa P10 apresentou melhor desempenho em comparação com a P9.

Esta investigación evaluó, en laboratorio, la eficiencia de los fungicidas de origen orgánico frente a los fungicidas químicos de uso convencional para controlar el crecimiento del Dactylonectria torresensis, considerada como una de las fitopatologías de importancia económica que afecta a la mora de castilla (Rubus glaucus) en Ecuador. El objetivo del estudio se basó en la necesidad imperante de buscar alternativas naturales y amigables con el ambiente, que permitan obtener alimentos limpios para la población. Para tal fin, se evaluó la eficiencia de los fungicidas convencionales de síntesis química: Azoxystrobin, Benomil, Carbendazim, Difeconazol, Fosetyl Aluminio, Tachigaren, Propiconazol, Penconazol, Metalaxil y Thiabendazole, cada uno en dosis de 100, 10 y 1 ppm, frente a la eficiencia de fungicidas de síntesis orgánica: aceite de neem, extracto de mirtáceas, extracto de ajo, sulfato cúplico pentahidratado y extracto de tomillo, aplicados en dosis de 300, 200, y 100 ppm. Se comprobó que el extracto de mirtáceas controló en 100 % del crecimiento micelial del Dactylonectria torresensis, y mostró resultados similares a los obtenidos con Carbendazim y Azoxystrobin. Se concluye, por lo tanto, que si existiera una alternativa para el control del hongo, esta podría ser utilizada comercialmente, y de esta manera disminuir el uso y los efectos nocivos de los agroquímicos convencionales.

[ES] Composites a base de hongos han demostrado ser una potencial alternativa a plásticos derivados del petróleo. Mediante el desarrollo de resinas biopliméricas cuya función principal es el recubrimiento protector de los micelios de hongo, es posible crear un nuevo tipo de material composite. Éste debe ser biodegradable, y en medida de lo posible, de base biológica., [EN] The decreasing natural fuel resources, the ascending fuel prices, and the increasing involvements of governments against climate change imply the need to find alternatives to synthetic plastic materials. Recently, new types of biopolymers have been developed that can be produced through biological growth. These include mycelium composites, which are capable of revalorising organic waste into a new type of environmentally friendly material. In this Master Thesis, the possibility of creating a biodegradable polymeric resin whose main function is the protection of the fungal material will be studied. For this purpose, the possible interaction between the resin and the fungal material will be investigated in order to develop a new type of composite material. To this end, a theoretical proposal will be made of the materials that could be used for the development of the resin, and its subsequent interaction with the mycelium. Additionally, furan resins will be studied, and a theoretical proposal will be made to obtain them.

El objetivo se enfocó en caracterizar el potencial antagonista de PGPR en inhibición al desarrollo micelial, conidios en F. oxysporum y esporas en M. roreri. La técnica de PCR se empleó para la identificación de F. oxysporum y M. roreri. Seleccionando las bacterias: Acinetobacter calcoaceticus BMR2-12, Klebsiella variicola BO3-4, Enterobacter asburiae BA4-19, Enterobacter asburiae PM3-14, Pseudomonas protegens CHA0, Pseudomonas veronii R4 y Bacillus subtilis. Se evaluaron actividades antagónicas: a) Inhibición micelial en F. oxysporum y M. roreri; b) Reducción en producción de conidios y esporas por 12 y 15 días post-incubación. La PCR confirmó la amplificación de 670 pb para F. oxysporum. La secuenciación de 750 pb definió un grado de similitud del 99% a M. roreri, al compararse con el GenBank de NCBI. La aplicación de B. subtilis es de mayor actividad antagónica a inhibición (micelial y conidios) con (95 y 90%) a F. oxyporum. La actividad de BO3-4 en M. roreri inhibe totalmente el desarrollo micelial y la producción de esporas 12 y 15 días post-incubación respectivamente. La selección de estos bio-controladores y su aplicación como consorcio ofrecerá una alternativa para beneficiar en la reducción de agroquímicos al cultivo de tomate y cacao.

International audience; Edible mushrooms are an important source for obtaining novel substances of nutritional and biopharmaceutical interest. In this regard, in Cuba, the consumption of mushrooms of the genus Pleurotus spp. has been promoted as part of the Urban Agriculture Program. Taking advantage of its availability and considering previous reports on their content of compounds with potential application, in this work, there was investigated the immunomodulatory and immunonutrition properties of biopreparations from this mushroom. New methodologies were developed to generate biopreparations from the mycelium and fruiting bodies of Pleurotus ostreatus. The obtained bioproducts were generated by biomass aqueous extraction and/or drying, which led to the registration of the NutriSetas® tradename. The bioproducts contained mainly carbohydrates (including ß-glucans) and proteins, among other secondary metabolites with potential biological activity. They showed M1-polarizing effects on macrophage populations, and the aqueous fraction obtained from the mycelium by submerged fermentation was able to stimulate the complement system alternative pathway. Noteworthy, the aqueous extract displayed radioprotective effects on the hematopoietic and immunological parameters when administered in a mice biomodel of ionizing radiation-induced secondary immunodeficiency. Similar immunostimulatory effects, either in the humoral or cellular immune responses, were found with dry and powdered preparations from fruiting bodies. Their immunonutritional effect in an experimental model of protein-energetic malnutrition in Balb/c mice evidenced nutritional recovery and immunological improvement status. This provided the first report of such an effect for edible mushroom preparations. This work received the Annual Award of the Cuban Academy of Sciences for the year 2017.; Los hongos comestibles son una fuente importante para la obtención de nuevas sustancias de interés nutricional y biofarmacéutico. En Cuba se ha promovido el consumo de hongos del género Pleurotus spp. como parte del Programa de Agricultura Urbana. En este trabajo se investigó las propiedades inmunomoduladoras e inmunonutricionales de preparaciones de este hongo, dada su disponibilidad y los informes previos sobre su contenido de compuestos con potencial aplicación para estos fines. Se establecieron nuevas metodologías para obtener biopreparaciones a partir del micelio y de los cuerpos fructíferos de Pleurotus spp., mediante la extracción acuosa de biomasa, el secado, o ambos, lo cual derivó en el registro de la marca comercial NutriSetas®. Los bioproductos contuvieron principalmente carbohidratos (incluidos los ß-glucanos) y proteínas, entre otros metabolitos secundarios con actividad biológica potencial. Las preparaciones tuvieron un efecto polarizador hacia fenotipo M1 en poblacionesde macrófagos, y la fracción acuosa obtenida del micelio mediante fermentación sumergida estimuló la ruta alternativa de activación del sistema del complemento. Notablemente, el extracto acuoso tuvo efecto radioprotector en los parámetros hematopoyéticos e inmunológicos al administrarlo en biomodelos de inmunodeficiencia secundaria inducida por radiación ionizante en ratones. Las preparaciones secas y en polvo de cuerpos fructíferos fueron igualmente inmunoestimuladoras de la respuesta inmune humoral y celular. Se evidenció su efecto inmunonutricional enun modelo de malnutrición proteica-energética en ratones Balb/c. Este fue el primer informe de tales efectos para preparaciones de hongos comestibles. Este trabajo mereció el Premio Anual de la Academia de Ciencias de Cuba para el año 2017

Pleurotus ostreatus is a producer of biomass and laccase, an enzyme used in fermentation processes for the hydrolysis of lignocellulosic substrate, with potential use in biofuel production and animal feed. Thus, there is a need to seek more appropriate regional substrate for the production of mycelial biomass and laccase. Hence, the aim of this study was to evaluate the effect of physical and chemical characteristics of agro-industrial byproducts in a substratum formulation for the mycelial growth and laccase production by P. ostreatus. The experiment was conducted with the milled raw materials: soy fiber, wheat bran, rice bran, corn grain and corn cob that were separated according to size and analyzed for carbon/nitrogen (C/N) ratio. Mycelial growth was evaluated on substratum in cylindrical tubes of borosilicate. Then laccase production was assessed using a 26-2 fractional factorial design with the variables: raw material granulometry and addition of minerals (copper, zinc, iron, cadmium and magnesium) in the substrate. The production of laccase was determined by oxidation of ABTS (2,2’-bisazin-(3-ethylbenzothiazoline-6-sulfonic acid). The results indicate that the most important factor for mycelial growth is the holding capacity of oxygen in the substratum. For mycelial growth of P. ostreatus the corn cob and wheat bran are the best components for the substrate. The other raw materials reduced the mycelial growth. However the most important factor for the induction of laccase production is the reduction of particle size, increasing the contact area between the mycelium and the substratum. Pleurotus ostreatus é um produtor de biomassa e lacase, enzima utilizada em processos fermentativos para a hidrólise de substratos lignocelulósicos, com potencial de utilização na produção de biocombustíveis e na alimentação animal. Desta forma, há a necessidade de buscar substratos regionais mais apropriados para a produção de biomassa micelial e de lacase. Assim o objetivo deste trabalho foi avaliar o efeito das características físico-químicas de subprodutos da agroindústria na formulação de substratos para o crescimento micelial e a produção de lacase por P. ostreatus. O experimento foi realizado com as matérias-primas: fibra de soja, farelo de trigo, farelo de arroz, grãos de milho e sabugo de milho que foram separadas em função da granulometria e analisadas quanto à relação carbono/nitrogênio (C/N). O crescimento micelial foi avaliado em meio de cultivo sólido particulado em tubos cilíndricos de borosilicato. Em seguida a produção de lacase foi avaliada utilizando um planejamento fatorial fracionário 26-2 com as variáveis: granulometria do meio de cultivo e adição de minerais (cobre, zinco, ferro, cádmio e magnésio) no meio de cultivo. A produção de lacase foi determinada pela oxidação do ABTS (ácido 2,2’-azino-bis-(3-etilbenzotiazolina-6-sulfônico). Os resultados indicam que o fator mais importante para o crescimento micelial é a capacidade de retenção de oxigênio do meio de cultivo. Para o crescimento micelial de P. ostreatus o sabugo de milho e o farelo de trigo são os melhores componentes do substrato. As demais matérias-primas reduziram o crescimento micelial. Entretanto o fator mais importante para a indução da produção de lacase é a redução do tamanho da partícula, com aumento da área de contato entre o micélio e o substrato.

O objetivo do trabalho foi avaliar o crescimento micelial in vitro de cinco linhagens de Agaricus blazei (ABL-05/53, ABL-04/49, ABL-03/44, ABL-99/30 e ABL-02/51), quando submetidas às temperaturas de 20 e 25ºC. Em câmara de fluxo laminar, discos das linhagens foram inoculadas no centro de placas de Petri contendo o meio CA (composto-ágar) e incubadas em estufa BOD. Após 48 horas, iniciaram-se as medidas do crescimento micelial, com auxílio de uma régua graduada em milímetros, através de quatro medições equidistantes entre si, até o momento em que, em um dos tratamentos, a colônia fúngica atingisse a proximidade das bordas da placa de Petri. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 5 x 2. Cada tratamento constou de sete repetições, correspondente a uma placa de Petri, totalizando setenta unidades experimentais. Verificou-se que o crescimento de A. blazei é influenciado pela temperatura de incubação, sendo que a temperatura de 25°C foi mais favorável para o crescimento micelial de todas as linhagens de A. blazei avaliadas, com destaque para as linhagens ABL-04/49 e ABL-03/44 que obtiveram as maiores médias de crescimento micelial nesta condição de temperatura ao final do ciclo de cultivo.AbstractThe objective of the work was to evaluate the in vitro mycelial growth of five A. blazei strains (ABL-05/53, ABL-04/49, ABL-03/44, ABL-99/30 and ABL-02/51) when submitted to the temperatures of 20 and 25 ºC. In a laminar flow chamber, discs of the strains were inoculated in the middle of Petri’s plates containing CA (compost-agar) medium and incubated in BOD. After 48 hours, measurements of the mycelial growth began, with the help of a ruler with scale in millimeters, by means of four equidistant measurements, until the moment when the fungal colony reached near the edges of the Petri’s plate in one of the treatments. The experimental design was totally randomized, in 5 x 2 factorial design. Each treatment consisted of seven repetitions, corresponding to one Petri’s plate, totalizing seventy experimental units. We verified that A. blazei growth is influenced by incubation temperature, being that the temperature of 25 ºC was more favorable for the mycelial growth of all A. blazei strains tested, with attention for ABL-04/49 and ABL-03/44 strains, which obtained the highest averages for mycelial growth under this temperature condition at the end of the cultivation cycle.

Introducción. Paracoccidioides brasiliensis es un hongo dimórfico térmico, que a temperatura ambiente se presenta como un moho productor de conidias, mientras que en el huésped se comporta como una levadura de gemación múltiple. Los mecanismos moleculares que rigen la germinación de conidia a micelio aún se desconocen.Objetivo. Estudiar en P. brasiliensis la cinética del proceso de germinación de conidia a micelio y determinar los genes expresados durante este proceso mediante la construcción y el análisis de una librería EST (Expressed Sequence Tag).Materiales y métodos. Para el estudio de la cinética de germinación, se produjeron y aislaron conidias de P. brasiliensis. Estas fueron incubadas en cultivos líquidos a 18°C por 24, 48, 72 y 96 horas, y se examinaron por microscopía de luz. A partir de conidias cultivadas por 96 horas, se construyó y caracterizó una librería EST, la cual representaría los genes expresados durante el proceso de germinación.Resultados. Durante el proceso de germinación de conidia a micelio, se observó 11,7±1,2%, 30±0,6%, 43±1,3% y 66±2,4% de germinación a las 24, 48, 72 y 96 horas de incubación, respectivamente. Además, se obtuvo una librería del proceso de germinación consistente en 129 secuencias agrupadas en cuatro secuencias contiguas y siete secuencias únicas, para un total de 11 posibles genes. Ocho secuencias (72,7%) no habían sido descritas anteriormente en otras librerías informadas para este hongo y podrían representar genes específicos de la germinación de conidia a micelio.Conclusiones. Éste es el primer reporte en el que se identifican genes no descritos anteriormente, que son expresados durante la germinación de conidia a micelio, proceso de gran importancia en la biología de P. brasiliensis.Introduction. Paracoccidioides brasiliensis is a thermo-dimorphic fungus. At room temperature it grows as a mold that produces conidia, whereas in the vertebrate host it grows as a multiple-budding yeast. The molecular mechanisms involved in the germination from the conidia to the mycelia process remain unknown.Objective. The kinetics of conidia to mycelia germination process were studied in the dimorphic fungus P. brasiliensis. Gene expression during this process was evaluated by construction and analysis of an EST library.Materials and methods. For the germination kinetics study, P. brasiliensis conidia were isolated as single cell units. Then, they were cultured at 18° C in BHI (brain-heart infusion) broth for 24, 48, 72 and 96 hr. After each perion, they were examined by light microscopy. From conidia harvested at 96 hr, an EST library was constructed; at this stage the gene expression was presumed to be maximal for the germination process.Results. During the conidia to the mycelia developmental process, the following germination rates were observed: at 24 hr, 11.7±1.2%; at 48 hr, 30±0.6%; at 72 hr, 43±1.3%; and at 96 hr, 66±2.4%. At the 96 hour stage, an EST library was constructed. It consisted of 129 sequences grouped in 4 contigs and 7 singlets for a total of 11 possible genes. Eight of the sequences had not been described previously in other EST libraries of this fungus.Conclusions. New genes were identified that were expressed during the conidia to the mycelia germination process and may represent genes specific to the germination process.

[cat] La disponibilitat de la majoria dels fongs micorízics comestibles depèn de la seva fructificació natural. La formació de bolets està relacionada amb les característiques de l'hàbitat i les condicions climàtiques, però aquestes dades no expliquen ni la dinàmica de la fructificació ni del miceli d’aquests fongs. L’establiment de plantacions a partir de plantes micorizades pot ser una alternativa per a l'obtenció de fongs comestibles ectomicorízics. El progrés de les noves tecnologies en la biologia molecular han permès el desenvolupament, implementació i ús de tècniques per a la traçabilitat dels fongs ectomicorízics comestibles. A la tesi s'ha demostrat que la PCR en temps real, amb el disseny d'oligonucleòtids específics per a la detecció i quantificació de miceli extraradical, ens permet determinar la concentració de miceli present al sòl tant a boscos com a plantacions. La micorizació de plantes amb espècies del complex Boletus edulis s'ha aconseguit en condicions de cultiu pur. S’han dissenyat encebadors i sondes específics per l’amplificació de B. edulis i Tuber melanosporum per PCR en temps real. S’ha estudiat la dinàmica estacional del miceli extraradical, les ectomicorizes i la producció de B. edulis i Lactarius deliciosus, a dos boscos de Sòria. També s’ha quantificat el miceli extraradical de Rhizopogon roseolus (a dues plantacions) i de T. melanosporum (a una plantació), des del seu establiment. Per altra banda s’ha quantificat el miceli extraradical de T. melanosporum en una tofonera natural i en set plantacions (d’uns 20 anys). Finalment, s’ha analitzat l'estructura genètica d’una població de T. melanosporum a una plantació productiva, determinat la distribució dels tipus de compatibilitat al sòl, i els genotips de micorizes i ascocarps fent us de marcadors microsatèl•lits. No s'ha trobat relació directa entre les quantitats de miceli del sòl i la producció per cap de les espècies estudiades, però s’ha correlacionat positivament les estructures vegetatives de B. edulis, R. roseolus i T. melanosporum. Els resultats obren la possibilitat d'utilitzar la quantificació de miceli del sòl per PCR en temps real com un bon indicador de la colonització de les arrels en condicions de camp. Les quantitats de miceli extraradical de B. edulis, L. deliciosus i R. roseolus i les micorizes de T. melanosporum s’han correlacionat amb diferents paràmetres climàtics. Finalment, ha estat possible determinar la distribució dels diferents genotips de T. melanosporum a una plantació, on es va trobar una estructura genètica espacial amb un patró de distribució no aleatori, resultant en zones de camp colonitzat per genets que compartien els mateixos tipus de compatibilitat., [eng] The availability of most edible ectomycorrhizal mushrooms depends on their natural fructification. Therefore, mycorrhizal plant production could be an alternative for obtaining ectomycorrhizal edible fungi. The first step to establish a plantation for a certain species of mushrooms is the production of plants, inoculated with the fungus, in order to be outplanted to field. The mycorrhization of plants with species of the Boletus edulis complex has been achieved under pure culture synthesis conditions. The production of B. edulis mycorrhizal plants under nursery conditions could be achieved by acclimation of in vitro-produced mycorrhizal plants, but needs still more research to determine an appropriate procedure. Sporocarp formation of these fungi is linked to habitat characteristics and climate conditions, but these data alone do not explain all the trends of fungal fruiting and dynamics. It could be hypothesized that the amount of soil mycelia could also be related to the production of carpophores. Progress of new technologies in molecular biology and the availability of fungal genomes have led to the development, implementation and use of techniques for the traceability of edible ectomycorrhizal fungi. Through the thesis it has been demonstrated that the real- time PCR technique, with the design of specific oligonucleotides for the detection and quantification of extraradical mycelium in soil, allows us to determine the concentration of soil mycelium in forests and plantations, increasing detection limits over conventional PCR. Specific primers and probes have been designed for B. edulis and Tuber melanosporum for real-time PCR amplification, allowing the traceability of these fungal species in the controlled production of edible mycorrhizal mushrooms. The annual belowground dynamics of extraradical soil mycelium, ectomycorrhizal root tips and sporocarp production of two ectomycorrhizal fungi, B. edulis and Lactarius deliciosus, have been studied in two different pine forests (Pinar Grande and Pinares Llanos, respectively) in Soria in permanent plots. Quantification of extraradical mycelium of Rhizopogon roseolus x Pinus pinea plantations (two in Cabils) and of T. melanosporum x Quercus ilex plantation (one in Cerc), in Catalunya has been carried out from its establishment until 24 or 48 months. T. melanosporum extraradical mycelium has also been quantified by real-time PCR in a natural truffle ground and in seven truffle orchards (around 20 years old) established in Tierra Estella and Valdorba sites (Navarra). Finally, the spatial genetic structure of T. melanosporum population was analyzed in a productive orchard (France). The distribution of the two T. melanosporum mating types was monitored in the soil. Ectomycorrhizas and ascocarps were mapped and genotyped using simple sequence repeat markers and the mating type locus and their genetic profiles were compared. No direct relationships were found between soil mycelium amounts and sporocarp production for any of the studied fungal species, but it was possible to obtain positive correlations between vegetative structures (ectomycorrhiza and extraradical mycelium) for B. edulis, R. roseolus and T. melanosporum. The results obtained open the possibility of using quantification of soil mycelium by real-time PCR as a good indicator for root colonization in field conditions (in natural areas or in manmade orchards), especially when a nondestructive sampling or less time consuming analysis were required. The extraradical mycelial amounts of B. edulis, L. deliciosus and R. roseolus and T. melanosporum mycorrhizas were correlated with climate parameters as temperature, rainfall, solar radiation, relative humidity and evapotranspiration. Moreover, it has been possible to map the distribution of different T. melanosporum genotypes trough the traceability of ascocarps, ectomycorrhizas and soil samples. A pronounced spatial genetic structure was found. A nonrandom distribution pattern of the T. melanosporum was observed, resulting in field patches colonized by genets that shared the same mating types.

Black spot, caused by Guignardia citricarpa, is one of the main diseases affecting citrus fruits. UV-C irradiation is known to have potential to be used as an alternative method to supplement or replace the use of fungicides, especially because it promotes resistance against pathogens. The aim of this work was to evaluate the in vitro effects of UV-C irradiation on G. citricarpa development and on the control of black spot in postharvest orange. Additionally, changes in skin color of the fruit as a result of UV-C treatment were evaluated. Mycelial growth, conidial germination and appressoria formation were evaluated in vitro after fungal exposure to different irradiation doses. Also, 'Valência' oranges naturally infected were submitted to different irradiation doses to check the possibility of in vivo control. Fruit were stored at 25ºC/80% RH and evaluated 3, 7, 10 and 14 days after treatment and area under the disease progress curve was calculated. UV-C irradiation affected conidial germination of G. citricarpa and apressorium formation. UV-C irradiation was not able to control citrus black spot on fruit at a satisfactory level; however, incidence of quiescent black spot lesions was lower on postharvest 'Valência' orange treated with 7.28 and 15.66 kJ m-2. Low UV-C doses did not affect the visual aspect of fruit. Thus, UV-C irradiation can contribute for the reduction of postharvest losses caused by citrus black spot and reduce the use or doses of fungicides on disease control. A pinta preta, causada por Guignardia citricarpa, é uma das principais doenças que afetam frutos cítricos. A irradiação UV-C tem potencial para ser utilizada como método alternativo para suplementar ou substituir o uso de fungicidas, especialmente por promover resistência contra patógenos. O objetivo deste trabalho foi avaliar os efeitos da irradiação UV-C sobre o desenvolvimento in vitro de G. citricarpa e no controle da pinta preta em laranja pós-colheita. Adicionalmente, foram avaliadas as alterações na cor da casca dos frutos. Crescimento micelial, germinação de conídios e formação de apressórios foram avaliados in vitro após a exposição do fungo a diferentes doses de irradiação. Frutos de laranja 'Valência' naturalmente infectados foram submetidos a diferentes doses de irradiação (0,52; 1,04; 3,13; 7,28; 15,66 e 31,20 kJ m-2) para verificar a possibilidade de controle in vivo. Os frutos foram armazenados a 25ºC/80% UR e avaliados 3, 7, 10 e 14 dias após o tratamento e a área abaixo da curva de progresso da doença foi calculada. A exposição à UV-C afetou a germinação de conídios de G. citricarpa e a formação de apressórios. A irradiação com UV-C não foi capaz de controlar a pinta preta de maneira satisfatória; no entanto, a incidência de lesões de pinta preta quiescentes foi menor em laranjas 'Valência' tratadas em pós-colheita com 7,28 e 15,66 kJ m-2. Doses baixas de UV-C não afetaram o aspecto visual dos frutos. Portanto, a irradiação UV-C pode contribuir para a redução de perdas pós-colheita causadas pela pinta preta dos citros e reduzir o uso ou as doses de fungicidas no controle desta doença.

Cassava (Manihot esculenta Crantz) is an important crop in Brazil and Pará is the major producer of roots. High temperature and humidity of tropical regions favor the development of various diseases, among them the cassava root rot. The objective of this study was to evaluate the effect of luminosity and culture medium on the mycelial growth and sporulation of Phytopythium sp. associated with different methods of inoculation on cassava roots. In vitro tests for pathogen growth were established in a 2 x 6 factorial design (luminosity x culture medium) with five replicates and the means were compared by t test (P≤0.05). The culture medium containing sweet cassava root produced greater mycelial development and higher pathogen sporulation and it was the most suitable medium for pathogen culture. The culture under absence of light generated better mycelial growth than culture under 12 hour of light. Regarding the type of inoculation, the response was better when deeper injuries were induced. RESUMO: A mandioca (Manihot esculenta Crantz) é uma importante cultura para o Brasil, onde o Pará é o principal produtor de raízes. Regiões tropicais com alta umidade e temperatura favorecem o desenvolvimento de diversas doenças, como as podridões de raiz. O presente estudo tem como objetivo avaliar o efeito da luminosidade e de meios de cultura no crescimento micelial e na esporulação de Phytopythium sp. e analisar métodos de inoculação do patógeno em raízes de mandioca destacadas. Os ensaios in vitro foram instalados em esquema fatorial 2x6 (luminosidade x meio de cultura), com cinco repetições e as médias comparadas pelo teste t (p≤0,05). O meio de cultura contendo raiz de mandioca mansa proporcionou maior desenvolvimento micelial e maior esporulação do patógeno e é o mais adequado para o cultivo do patógeno. O cultivo sob ausência de luz gerou melhor crescimento micelial do que o cultivo sob 12 horas de luz. Quanto ao tipo de inoculação, a resposta foi melhor nas raízes que obtiveram ferimentos mais profundos.