Selection and characterization of Beauveria spp. isolates to control the broad mite Polyphagotarsonemus latus (Banks, 1904) (Acari: Tarsonemidae) / Seleção e caracterização de isolados do fungo Beauveria spp. visando ao controle do ácaro branco Polyphagotarsonemus latus (Banks, 1904) (Acari: Tarsonemidae)

Abstract This study was performed under laboratory conditions to identify isolates of the fungus Beauveria spp. that can control Polyphagotarsonemus latus in the greenhouse and field. Thirty Beauveria spp. isolates were tested by spraying 1 mL conidia (1 × 108 conidia/mL) on pepper leaf discs containing 15 mites. Evaluations were performed on the 3rd and 6th day post application by counting the number of dead mites. Vegetative growth and conidial production were measured from the selected isolates, and bioassays were conducted in the greenhouse on bean seedlings in plastic pots. The isolate Unioeste 53 was selected, and a conidial suspension (1 × 108 conidia/mL) was applied with a backpack sprayer. The evaluation consisted of pre- and post-treatment counts of the number of live mites on ten leaflets in both the plots treated with the fungus and control plots, and the same procedure was followed for the field experiment. In the laboratory, the Unioeste 53 isolate resulted in total and confirmed mortality rates of 70% and 57.7%, respectively. In the greenhouse, the population decreased by 76.71% by the 16th day after application. In the field, the population decreased by 66% by the 12th day after application, demonstrating the potential of this fungus for mite management.

Resumo Este trabalho teve por objetivo selecionar isolados do fungo Beauveria bassiana em condições de laboratório com potencial de uso em casa de vegetação e campo no controle do ácaro branco. Foi realizada uma seleção com 30 isolados de Beauveria spp. através de pulverização direta de conídios (1 × 108 conídios/mL) sobre discos foliares de pimenta contendo 15 ácaros. As avaliações foram realizadas no terceiro e sexto dia contando-se o número de mortos, e confirmação do patógeno em câmara úmida. Parâmetros de crescimento vegetativo e produção de conídios foram avaliados. No bioensaio em casa de vegetação foram preparados vasos com plantas de feijão e fez-se a aplicação do Unioeste 53 (1 × 108 conídios/mL), utilizando pulverizador costal, a avaliação constou da contagem prévia e posterior à aplicação do número de ácaros vivos em 10 folíolos, tanto nas parcelas destinadas ao tratamento com fungo, quanto na testemunha. A fase de campo seguiu os mesmos padrões, porém, com área experimental total de 225 m2, com oito parcelas de 10,24 m2, sendo 4 testemunhas e 4 onde foi aplicado o isolado Unioeste 53 seguindo metodologia de aplicação e avaliação já descritas para casa de vegetação. Em laboratório o isolado Unioeste 53 causou mortalidade total de 70% e 57,7% de mortalidade confirmada. Em casa de vegetação, apresentou redução da população de 76,71% 16 dias após aplicação, já em campo, a redução da população foi de 66% após 12 dias da aplicação, demonstrando o potencial do ácaro pelo fungo.

Arbuscular mycorrhizal fungi in Mimosa tenuiflora (Willd. ) Poir from Brazilian semi-arid

Abstract Many plant species from Brazilian semi-arid present arbuscular mycorrhizal fungi (AMF) in their rhizosphere. These microorganisms play a key role in the establishment, growth, survival of plants and protection against drought, pathogenic fungi and nematodes. This study presents a quantitative analysis of the AMF species associated with Mimosa tenuiflora, an important native plant of the Caatinga flora. AMF diversity, spore abundance and root colonization were estimated in seven sampling locations in the Ceará and Paraíba States, during September of 2012. There were significant differences in soil properties, spore abundance, percentage of root colonization, and AMF diversity among sites. Altogether, 18 AMF species were identified, and spores of the genera Acaulospora, Claroideoglomus, Dentiscutata, Entrophospora, Funneliformis, Gigaspora, Glomus, Racocetra, Rhizoglomus and Scutellospora were observed. AMF species diversity and their spore abundance found in M. tenuiflora rhizosphere shown that this native plant species is an important host plant to AMF communities from Brazilian semi-arid region. We concluded that: (a) during the dry period and in semi-arid conditions, there is a high spore production in M. tenuiflora root zone; and (b) soil properties, as soil pH and available phosphorous, affect AMF species diversity, thus constituting key factors for the similarity/dissimilarity of AMF communities in the M. tenuiflora root zone among sites.

Ajuste de un método rápido para la cuantificación de suspensiones de esporas de Fusarium spp. en fitopatología / Adjustment of a rapid method for quantification of Fusarium spp. spore suspensions in plant pathology

La cámara de Neubauer es un método ampliamente utilizado para cuantificar suspensiones de esporas. Sin embargo, esta técnica requiere personal entrenado y un tiempo considerable. La espectrofotometría demostró ser un método rápido, simple y preciso para estimar la concentración de esporas de aislados del género Fusarium. En este artículo breve presentamos una fórmula lineal ajustada para relacionar la absorbancia a 530nm con el número de conidios en suspensiones utilizadas en pruebas fitopatológicas

The use of a Neubauer chamber is a broadly employed method when cell suspensions need to be quantified. However, this technique may take a long time and needs trained personnel. Spectrophotometry has proved to be a rapid, simple and accurate method to estimate the concentration of spore suspensions of isolates of the genus Fusarium. In this work we present a linear formula to relate absorbance measurements at 530nm with the number of microconidia/ml in a suspension

Relación in vitro entre cylindrocarpon cylindroides y neonectria fuckeliana asociados a cancros fustales de pinus radiata en Chile / In vitro relationship between cylindrocarpon cylindroides and neonectria fuckeliana associated with stem cankers on pinus radiata in Chile

Desde el punto de vista estrictamente micológico, se ha discutido por décadas la relación de Cylindrocarpon cylindroides como anamorfo de Neonectria fuckeliana, lo que entre otras consecuencias, ha incidido en la controversial ubicación taxonómica de este teleomorfo. Se añade a esto que en patología forestal se ha brindado poca atención a la presencia de C. cylindroides dentro del ciclo de la enfermedad causada por Neonectria fuckeliana en coníferas, razón por la cual los estudios específicos respecto de este anamorfo han sido también muy escasos. El presente trabajo tuvo como objetivo verificar la relación entre C. cylindroides y Neonectria fuckeliana, asociados a cancros en troncos de Pinus radiata en Chile, mediante el análisis de las características macro y micromorfológicas que ellos manifiestan en cultivos in vitro, además de análisis de tipo molecular. Se pudo constatar que ambos agentes dieron origen a colonias con idénticas características macro y micromorfológicas, destacando entre éstas la producción de abundantes conodióforos y microconidios del tipo Acremonium, el cual ya ha sido señalado en anteriores estudios como estado anamorfo de Neonectria fuckeliana. El que este mismo estado asexual del tipo Acremonium haya sido la manifestación in vitro tanto de C. cylindroides como de Neonectria fuckeliana, permitió confirmar la relación existente entre estos dos agentes en estudio, la que también fue ratificada mediante los análisis moleculares realizados.

From the point of view strictly mycological has been discussed for decades the relationship of Cylindrocarpon cylindroides as anamorph of Neonectria fuckeliana, which among other consequences, has influenced the controversial taxonomic status of this teleomorph. Add to this that in forest pathology has given little attention to the presence of C. cylindroides within the cycle of the disease caused by Neonectria fuckeliana on conifers, why specific studies regarding this anamorph have been very few. This study aimed to verify the relationship between C. cylindroides and Neonectria fuckeliana associated with cankers on trunks of Pinus radiata in Chile, by analyzing the macro and micromorphological characteristics they manifest in cultures in vitro, further analysis type molecular. It was found that both agents gave rise to colonies with identical macro and micromorphological characteristics, highlighting among them the production of abundant microconidia and conidiophores of Acremonium type, which has already been noted in previous studies as anamorph state of Neonectria fuckeliana. The asexual state that this same type of Acremonium has been the in vitro demons-tration of both C. cylindroides as Neonectria fuckeliana, allowed us to confirm the relationship between these two agents in the study, which was also ratified by the molecular analyzes performed.

Arbuscular mycorrhizal fungi in saline soils: vertical distribution at different soil depth

Arbuscular mycorrhizal fungi (AMF) colonize land plants in every ecosystem, even extreme conditions such as saline soils. In the present work we report for the first time the mycorrhizal status and the vertical fungal distribution of AMF spores present in the rhizospheric soil samples of four species of Chenopodiaceae (Allenrolfea patagonica, Atriplex argentina, Heterostachys ritteriana and Suaeda divaricata) at five different depths in two saline of central Argentina. Roots showed medium, low or no colonization (0-50%). Nineteen morphologically distinctive AMF species were recovered. The number of AMF spores ranged between 3 and 1162 per 100 g dry soil, and AMF spore number decreased as depth increased at both sites. The highest spore number was recorded in the upper soil depth (0-10 cm) and in S. divaricata. Depending of the host plant, some AMF species sporulated mainly in the deep soil layers (Glomus magnicaule in Allenrolfea patagonica, Septoglomus aff. constrictum in Atriplex argentina), others mainly in the top layers (G. brohultti in Atriplex argentina and Septoglomus aff. constrictum in Allenrolfea patagonica). Although the low percentages of colonization or lack of it, our results show a moderate diversity of AMF associated to the species of Chenopodiaceae investigated in this study. The taxonomical diversity reveals that AMF are adapted to extreme environmental conditions from saline soils of central Argentina.

Detección del sinanamorfo Cylindrocarpon cylindroides var. Tenue sobre cancros causados por Neonectria fuckeliana en Pinus radiata / Detection of sinanamorph Cylindrocarpon cylindroides var. tenue on Neonectria fuckeliana cankers in Pinus radiata

El presente trabajo tuvo por finalidad reportar y analizar la presencia de estructuras fungosas (esporodoquios) sobre cancros causados por Neonectria fuckeliana en árboles de Pinus radiata en Chile. Las muestras fueron colectadas en las Regiones de La Araucanía y de Los Ríos y fueron analizadas en el laboratorio. Los resultados de los análisis morfológicos y taxonómicos permitieron concluir que los esporodoquios hallados correspondían al sinanamorfo de Neonectria fuckeliana (forma cylindrocarpon cylindroides var tenue), siendo el primer reporte en el país. Estos antecedentes contribuyen al conocimiento y comprensión del ciclo patológico y epidemiológico de Neonectria fuckeliana en plantaciones de Pinus radiata.

The present work was aimed at reporting and analyzing the presence of fungal structures (sporodochia) present on cankers caused by Neonectria fuckeliana in Pinus radiata trees in Chile. The samples were collected in the regions of La Araucanía and Los Ríos and analyzed in the laboratory. The results of morphological and taxonomic analysis led to the conclusion that thesporodochia found corresponded to sinanamorph of Neonectria fuckeliana (cylindrocarpon cylindroides var. tenue morph), the first report in the country. This work contribute to understanding and comprehension of the disease cycle and epidemiology of Neonectria fuckeliana on plantations of Pinus radiata.

Occurrence of Brettanomyces/Dekkera in Brazilian red wines and its correlation with ethylphenols

The yeast Brettanomyces/Dekkeracan cause important spoilage in wines, with the production of ethylphenols and other off-flavor compounds. This study aimed at determining the presence of this yeast and the ethylphenols produced by them in Brazilian red wines, establishing their relationship with other chemical characteristics. Isolates of Brettanomyces/Dekkerawere quantified by plating 126 samples of dry red wine in selective culture medium, while ethylphenols were analyzed by solid phase extraction and GC/FID. Free and total SO2, alcohol, total dry extract, residual sugar, total and volatile acidity, and pH were also determined. Brettanomyces/Dekkerawas present in 27% of samples. Ethylphenols were detected in most samples, with amounts higher than the threshold limit of 426 mg/L found in 46.03% of samples. The majority of wine samples showed inadequate levels of SO2and residual sugars, facts that might facilitate microbial spoilage. The passage in barrels and the grape varieties (Cabernet Sauvignon and Merlot), did not show any influence on the levels of contamination or ethylphenols contents. The prevalence of Brettanomyces/Dekkeraand the concentrations of ethylphenols were high considering the sensory impact they can cause. The growth of Brettanomyces/Dekkerawas dependent on the levels of SO2and alcohol of wines. Knowledge of the contamination, the presence of ethylphenols, and their relationship with the chemical characteristics of wines can entice effective measures to prevent Brettanomyces/Dekkeraand contribute to improve the general quality of Brazilian red wines.

Efficacy of aqueous garlic extract on growth, aflatoxin B1 production, and Cyto-morphological aberrations of Aspergillus flavus, causing human ophthalmic infection: topical treatment of A. flavus keratitis

By using agar well diffusion assay, antifungal activity of aqueous extract prepared from Egyptian garlic (Allium sativum L.) was evaluated in vitro against two strains of Aspergillus flavus (OC1 and OC10) causing human ocular infection. The recorded minimum inhibitory concentration (MIC) for growth inhibition of both strains was 3.60 mg/ml. Aqueous garlic extract (AGE) was used in successive in vivo tests as an attempt to cure rabbit's fungal keratitis caused by A. flavus OC1. Findings showed that diluted preparation of AGE was effective topical antifungal agent and succeeded to cure severe A. flavus keratitis in a time course less than 10 days without any observable side effects. Microscopic examination showed that AGE induced deleterious cyto-morphological aberrations inA. flavus target cells. AGE applied to Czapek's broth via contact method was more effective on growth, spores and aflatoxin B1 production than AGE applied to the same broth at the same concentration via fumigation method.

Aflatoxin contamination in stored rice variety PAU 201 collected from Punjab, India.

Background & objectives: The present study was carried out on stored rice variety PAU 201 in Punjab that was not permitted for milling and public distribution due to the presence of damaged grains at levels exceeding the regulatory limits of 4.75 per cent. The aim of the study was to determine fungal and aflatoxin contamination in the rice samples to assess hazard from the presence of damaged grains. Presence of iron in discoloured rice grains was also assessed. Methods: Stored samples of paddy of PAU 201 rice variety were collected from six districts of Punjab, milled and analysed for presence of fungal and aflatoxin contamination. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and Prussian blue staining was used to determine fungal spores and presence of iron, respectively. Results: Aflatoxin analysis of rice samples indicated that none exceeded the Food Safety and Standards (Contaminants, Toxins and Residues) Regulations, 2011 tolerance limit of 30 μg/kg and majority of the samples had levels <15 μg/kg. The proportion of damaged grains exceeding the limit of 5 per cent was observed in 85.7 per cent of the samples. SEM and Prussian blue staining and EDX analysis of black tipped and pin point damaged rice grains did not show presence of fungal structures and presence of iron. Interpretation & conclusions: The results of the study indicated that the stored rice samples did not pose any health concern with respect to aflatoxin contamination as per the criteria laid down by the Food Safety and Standards Authority of India.

Isolation and characterization of an Ashbya gossypii mutant for improved riboflavin production

The use of the filamentous fungus, Ashbya gossypii, to improve riboflavin production at an industrial scale is described in this paper. A riboflavin overproducing strain was isolated by ultraviolet irradiation. Ten minutes after spore suspensions of A. gossypii were irradiated by ultraviolet light, a survival rate of 5.5% spores was observed, with 10% of the surviving spores giving rise to riboflavin-overproducing mutants. At this time point, a stable mutant of the wild strain was isolated. Riboflavin production of the mutant was two fold higher than that of the wild strain in flask culture. When the mutant was growing on the optimized medium, maximum riboflavin production could reach 6.38 g/l. It has even greater promise to increase its riboflavin production through dynamic analysis of its growth phase parameters, and riboflavin production could reach 8.12 g/l with pH was adjusted to the range of 6.0-7.0 using KH2PO4 in the later growth phase. This mutant has the potential to be used for industrial scale riboflavin production.

Development and characterization of hybrids from native wine yeasts

For commercial purposes, the winemaking industry is constantly searching for new yeast strains. Historically, this has been achieved by collecting wild strains and selecting the best for industrial use through an enological evaluation. Furthermore, the increasing consumer demands have forced the industry to incorporate new strategies such as genetic engineering to obtain improved strains. In response to the lack of public acceptance of this methodology, alternative strategies based on breeding have gained acceptance in recent years. Through the use of conjugation of individual spores without the support of genetic engineering methods we generated intraspecific hybrids from wild strains with outstanding enological characteristics and interdelta fingerprinting was used to confirm the hybrid condition. A detailed enological characterization of the hybrids in synthetic and natural must indicates that physiological parameters such as sporulation, residual sugar, ethanol yield and total nitrogen uptake are within the levels determined for the parental strains, however, other parameters such as growth rate, lag phase and ethanol production show statistical differences with some parental or commercial strains. These findings allow us to propose these hybrids as new wine-making strains.

Ultrastructural study of the mycelial phase of clinical isolates of Sporothrix schenckii obtained from feline, canine and human cases of sporotrichosis

Using transmission electron microscopy, we studied the presence of melanin and cell wall thickness of clinical isolates of Sporothrix schenckii obtained from cats, dogs and humans as compared to reference strains. We detected differences regarding presence of the melanin among the clinical isolates of S. schenckii and a correlation between presence of melanin and cell wall thickness.

Distribuição de esporos de Cladosporium sppno ar atmosférico de Caxias do Sul, RS, Brasil,durante dois anos de estudo / Cladosporium spp spores distribution in the atmospheric air of Caxias do Sul-RS, Brazil, during a two-year study

Os esporos de fungos estão distribuídos em grande quantidade naatmosfera e, alguns deles, apresentam capacidade de causar doençasem seres humanos, animais e vegetais. Dentre os variados táxons destaca-se Cladosporium spp, um dos fungos mais cosmopolitas e de maiorconcentração no ar. Esporos de Cladosporium spp têm sido caracterizadoscomo importantes alérgenos.Objetivos: Medir as concentrações de esporos de Cladosporium sppna atmosfera de Caxias do Sul, RS, Brasil, durante os anos de 2001 e2002 e avaliar a relação destas, com parâmetros meteorológicos.Métodos: Amostras diárias foram coletadas, utilizando um aparelhotipo Hirst (Burkard®).Resultados: Os resultados mostraram que Cladosporium spp tempresença constante no ar. Em 2001 foram contabilizados 133.586 esporos/m3, com valor máximo diário de 3.265 esporos/m3 e mensal de24.912 esporos/m3, no mês de março. Em 2002 o número total foi de118.766 esporos/m3 com máximo diário de 4.470 esporos/m3 e mensalde 29.816 esporos/m3, em janeiro. A análise com os parâmetrosmeteorológicos mostrou correlação positiva com temperatura média enegativa com a umidade. Os períodos de maior concentração ocorreramcom temperaturas médias mais elevadas, no entanto, a umidade altatem um efeito negativo na distribuição destes esporos por favorecer ahidratação dos mesmos, que sedimentam ao solo.Conclusão: Os dados obtidos podem ser úteis nas áreas da patologiahumana, especialmente nos processos alérgicos, na patologia animal evegetal, em trabalhos com finalidades de preservação de acervo cultural,no controle de infecções e na ecologia.

Fungal spores are distributed in large amounts in the outdoor air, andsome of them may cause diseases in human beings, animals, and plants.Among several taxa, Cladosporium spp is one of the most ubiquitous andmost widely distributed, being found in high concentrations in the air.Cladosporium spp spores have been classified as important allergens,and are, therefore, important to the study of allergies.Objectives: To measure the concentrations of Cladosporium sppspores in the outdoor air of Caxias do Sul, Southern Brazil, during 2001and 2002, and to evaluate the association of these concentrations withmeteorological parameters.Methods: Daily samples were collected using a Hirst sampler(Burkard®).Results: The results showed that Cladosporium spp spores are oftenpart of the air. In 2001, the total amount was 133,586 spores/m3; withmaximum daily and monthly concentration of 3,265 spores/m3, and24,912 spores/m3 in March, respectively. In 2002, the total amount was118,766 spores/m3; with maximum daily and monthly concentration of4,470 spores/m3 and 29,816 spores/m3 in January. The meteorologicalparameters showed a positive correlation with the temperature averageand a negative one regarding humidity. The highest levels were found athigher temperature averages, however, elevated humidity has a negativeeffect on the distribution of these spores, contributing to their hydrationand deposition on the soil.Conclusions: The data obtained can be useful in human pathologyarea - especially in allergy - animal and plants pathology, in studies ofcultural inventory preservation, infection control and ecology.

Screening for ligninolytic enzymes from autochthonous fungi and applications for decolorization of Remazole Marine Blue / Triagem de enzimas ligninolíticas de fungos autóctones e aplicações para descoloramento de Remazole Marine Blue

This study presents new and alternative fungal strains for the production of ligninolytic enzymes which have great potential to use in industrial and biotechnological processes. Thirty autochthonous fungal strains were harvested from Bornova-Izmir in Turkiye. In the fresh fruitbody extracts laccase, manganese peroxidase and lignin peroxidase activities, which are the principal enzymes responsible for ligninocellulose degradation by Basidiomycetes, were screened. Spores of some of the basidiomycetes species such as Cortinarius sp., Trametes versicolor, Pleurotus ostreatus, Abortiporus biennis, Lyophyllum subglobisporium, Ramaria stricta, Ganoderma carnosum, Lactarius delicious ve Lepista nuda were isolated and investigated optimum cultivation conditions in submerged fermentation for high yields of ligninolytic enzyme production. In addition, isolated fungal strains were monitored on agar plates whether having the capability of decolorization of a textile dye Remazol Marine Blue.

Este estudo apresenta novas cepas de fungos produtores de enzimas ligninolíticas com potencial de aplicação em processos industriais e biotecnológicos. Trinta cepas de fungos autóctones foram obtidos em Bornova-Izmir, Turquia. Os extratos frescos dos corpos de frutificação foram submetidos à triagem de atividade de lacase, manganês peroxidase e lignina peroxidase, que são as principais enzimas de degradação de ligninocelulose pelos Basidiomycetes. Foram isolados esporos de Cortinarius sp, Tramnetes versicolor, Pleorotus ostreatus, Abortiporus biennis, Lyophyllum subglobisporium, Ramaria stricta, Ganoderma carnosum, Lactarius delicius ve Lepista desnuda, investigando-se as condições ótimas de cultivo em fermentação submersa para produção de enzimas ligninolíticas com elevado rendimento. Além disso, as cepas fúngicas isoladas foram monitoradas em placas de ágar quanto a capacidade de descoloramento do corante têxtil Remazole Marine Blue.

Spore production in Paecilomyces lilacinus (Thom. ) samson strains on agro-industrial residues / Produção de esporos em linhagens de Paecilomyces lilacinus (Thom. ) samson em resíduos agro-industriais

Paecilomyces lilacinus has potential for pests control. We aimed to analyze mycelial growth and spore production in P. lilacinus strains in several agro-industrial residues and commercial media. This study suggests alternative nutrient sources for fungi production and that the biotechnological potential of agro-industrial refuses could be employed in byproducts development.

Paecilomyces lilacinus apresenta potencial para controle de pragas. O objetivo deste trabalho foi analisar o crescimento micelial e a produção de esporos de linhagens de P. lilacinus em resíduos agro-industriais e meios comerciais. Este estudo sugere fontes alternativas para produção de fungos com potencial biotecnológico para desenvolvimento de bioprodutos.

Comparison of methodologies for conidia production by Alternaria alternata from citrus / Comparação de metodologias para produção de conídios por Alternaria alternata do citros

Conidia production is a problem in the study of Alternaria alternata from citrus. Thus, this study aimed to compare existing methodologies for conidial production of A. alternata isolated from Ponkan tangerine (2 isolates), Cravo lemon (1 isolate), Pêra orange (2 isolates) and Murcott tangor (1 isolate). The methodologies used were conidia production with 12 and 24 hours under white fluorescent light, evaluation with 24 and 48 hours after applying fungal mycelium stress technique, cold stress followed by injury of mycelium and evaluation with 24 hours, using healthy vegetable tissue and the use of black fluorescent near ultraviolet (NUV) lamp. Satisfactory result was obtained with A. alternata isolate from Murcott tangor, with the production of 2.8 x 10(5) conidia mL-1, when fungal mycelium was stressed (Petri dish with 66.66 percent of fungi growth) and subsequently 24 h of growth. The use of white light (24 h) and black fluorescent NUV lamp also induced expressive conidia production by one isolate of Ponkan tangerine, which produced 17.2 x 10(5) and 10.1 x 10(5) conidia mL-1 and another of Murcott tangor, which produced 13.9 x 10(5) and 10.1 x 10(5) conidia mL-1, respectively. The remaining methodologies analyzed in this study were not able to induce conidia production in satisfactory quantity. The use of both mycelium stress technique and white light (24 h) and black fluorescent NUV lamp allowed the production of enough quantities of conidia to be used in vitro (detection of fungitoxic substances)and in vivo (pathogenicity test)assays, respectively.

A produção de conídios consiste em problema no estudo de Alternaria alternata do citros. Assim, este estudo objetivou comparar metodologias existentes para a produção de conídios de A. alternata por dois isolados de tangerina Ponkan, um de limão Cravo, dois de laranja Pêra e um de tangor Murcott. As metodologias empregadas foram a produção de conídios com 12 e 24 horas sob luz branca, avaliação com 24 e 48 horas após estressamento do micélio do fungo, choque térmico com imediato estressamento do micélio e avaliação com 24 horas, produção de conídios pelo emprego de tecido vegetal sadio e o emprego de luz negra ultravioleta. Produção satisfatória de conídios foi obtida com o isolado de A. alternata de tangor Murcott, a qual foi de 2,8 x 10(5) conídios mL-1, mediante emprego da técnica de estressamento da colônia e cultivo do fungo por 24 horas. Os empregos de luz branca (24 h) e negra ultravioleta promoveram expressiva produção de conídios por um isolado de tangerina Ponkan, a qual foi de 17,2 x 10(5) e 10,1 x 10(5) conidios mL-1 e por outro de tangor Murcott, a qual foi de 13,9 x 10(5) e 10,1 x 10(5) conídios mL-1, respectivamente. As outras metodologias analisadas neste estudo não foram capazes de induzir a produção de conídios em quantidade satisfatória. Com o emprego das técnicas de estressamento do micélio e a utilização de luz branca (24 h) e negra ultravioleta, tornou-se possível obter quantidades de conídios suficientes para serem utilizadas em testes in vitro (detecção de substâncias fungitóxicas)e in vivo (testes de patogenicidade), respectivamente.

Morphological and cytochemical characterization of spores and gills of Lepista sordida (Fungi: Basidiomycota) / Caracterização morfológica e citoquímica dos esporos e lamelas de Lepista sordida (Fungi: Basidiomycota)

Some ultrastructural and cytochemical aspects of Lepista sordida are described. Basidiospores with verruculose and irregular ornamentations were observed through scanning electron microscopy. Confocal microscopy indicated that most of them exhibited a single large lipid body, no acidic vesicles and nucleus localized in the cell periphery.

Este trabalho descreve aspectos ultraestruturais e citoquímicos de Lepista sordida. Basidiósporos recobertos com ornamentações verruculosas e irregulares foram observados através de microscopia eletrônica de varredura. Através de microscopia confocal verificou-se que a maioria apresentava um grande corpo lipídico, ausência de vesículas ácidas e núcleo localizado na periferia.

Fungal spores and pollen as potential nutritional additives for the cross spider Araneus diadematus Clerck (Araneae, Araneidae) / Esporas fúngicas y polen como potenciales aditivos nutricionales para la araña del jardín Araneus diadematus Clerck (Araneae, Araneidae)

Prior to make a new cobweb, the Araneus diadematus Clerck cross spider eats its old web regulary everyday. In this paper we issue a quantitative and qualitative analysis of pollen grains and fungal spores present in the cob web, which might contribute to the diet of this arachnide. Cob webs were collected at the Natural Park of Ticino (Pavia, northern Italy). Fungal spores and pollen grains were taxonomically counted and identified for each sample. Quantitative analysis showed that both spores and pollen present in the cob webs exhibited some seasonal variation as regards quantity, whereas the qualitative analysis revealed that spores and pollen grains belong to 14 and 7 taxa, respectively. Alternaria, Cladosporium, Fusarum were the most frequent fungal taxa while Urticaceae, Betulaceae and Poaceae became the most representative plant families. About 5700 fungal spores and 2000 pollen grains were found to be present in the cob web of this spider everyday. Based on this information, it is possible to think that the aeroplancton stuck to the cob web can become a nutritional additive for the diet of this arachnide.

Antes de fabricar su telaraña, la araña del jardín Araneus diadematus Clerck, regularmente, cada día se come la antigua. En este estudio aportamos un análisis cuantitativo y cualitativo de los granos de polen y Esporas fúngicas retenidas en la telaraña, los cuales podrían contribuir a la dieta de este arácnido. Las telarañas fueron colectadas en el Parque Natural del Ticino (Pavia, N. Italia). Para cada muestra, las esporas fúngicas y los granos de polen fueron contabilizados e identificados taxonómicamente. El análisis cuantitativo mostró que las esporas y el polen retenidos en las telarañas presentaron variación estacional en cantidad, mientras con el análisis cualitativo se determinó que las esporas y los granos de polen pertenecen a 14 y 7 taxa respectivamente. Alternaria, Cladosporium, Fusarium fueron los taxa fúngicos más frecuentes, mientras Urticaceae, Betulaceae y Poaceae fueron las familias de plantas más representadas. Se determinó que aproximadamente unas 5700 esporas fúngicas y 2000 granos de polen fueron retenidos en la tela de esta araña cada día. Con estos antecedentes, se puede pensar que el aeroplanctón adherido a la telaraña puede constituir una aporte nutritivo en la dieta de este arácnido.