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- Controlo de Sclerotinia homoeocarpa em relva com compostos orgânicosPublication . Coelho, Luísa; Dionísio, Lídia; Guerrero, Carlos; Reis, MárioOs relvados são suscetíveis a doenças causadas por fungos, sendo Sclerotinia homoeocarpa um dos que causa maiores prejuízos em muitos países. A compostagem permite a valorização e tratamento de resíduos orgânicos, originando compostos com aplicações agrícolas, nomeadamente para controlo de doenças causadas por patogénicos do solo. Produziram-se dois compostos, designados P1 e P2, por compostagem de resíduos agroindustriais, em pilhas com arejamento por reviramento. Desde o final da fase termofílica até ao final dos processos de compostagem recolheram-se amostras onde se isolaram e identificaram fungos presentes em ambos os compostos. Dos isolados, 26 apresentaram potencial antagonista, sendo 12 provenientes de P1 e 14 de P2. Realizaram-se ensaios in vitro, pelo método de confrontação direta, para avaliar a capacidade antagonista destes fungos para S. homoeocarpa. Doze dos isolados, dos géneros Trichoderma, Fusarium e Bionectria, impediram o crescimento de S. homoeocarpa, com taxas de inibição entre 52 e 68%. Os compostos obtidos foram também testados, in vivo, em relva (Agrostis stolonifera L.) cultivada em vaso. No cultivo em vaso, usando os compostos como substratos, verificou-se redução da área de relva afetada pela doença, principalmente em P2. Os compostos testados controlaram S. homoeocarpa tanto in vitro como em vaso destacando-se o composto P2.
- Biodetection of turfgrass fungal diseases using sniffer dogsPublication . Serrão, M.; Coelho, Luísa; Dionísio, Lídia; Guerrero, Carlos; Duarte, AmilcarThe results in this work evaluated the sensitivity and specificity of the olfactory capacity of the intervening dog in the fungus biodetection. On 100 attempts, a sensitivity and a specificity of 100% (Table 1) were obtained for the biodetection of the fungus Sclerotium rolfsii when the 4-year-old English Springer Spaniel female dog was faced to a straight line of 5 equally distanced Falcons. The post-inoculation time of the samples, used in the sessions, varied between 24 and 72H, however there was no difference in the detection response by the female dog Julieta. This is also a noteworthy additional fact, given the potential for prevention that can represent the detection of a fungus with such a short post-inoculation time. Further work is being established to assess the olfactory ability to detect the presence of the fungus in inoculated turfgrass samples and finally to detect it in the field.
- Application of unsteady-state heat transfer equations to thermal process of morcela de arroz from Monchique region, a portuguese traditional blood sausagePublication . Pereira, Jorge; Ferreira-Dias, S.; Dionísio, Lídia; Patarata, L.; Matos, T. J. S.Morcela de Arroz (MA) is a popular cooked blood and rice sausage produced following empirical procedures in the Monchique region, south of Portugal. Presenting high pH (about 6.5) and water activity (around 0.97), it is commercialized without preservatives, unpacked and with restricted commercialization period (1 week at 0C-5C). The aim of this study was (i) to assess the adequacy of unsteady-state heat transfer equations (USHTE) using Heisler charts to predict temperature in the centre of the product and the time needed to attain the temperature needed for cooking and (ii) to determine if the thermal treatment traditionally applied complies with the recommendations for refrigerated processed foods of extended durability (REPFEDs). A very good fit of USHTE to the experimental time/temperature data was observed. MA thermal process complies with the REPFEDs recommendations. Bacillus cereus and Clostridium perfringens were not detected in any of the tested samples.
- First report of curvularia trifolii causing curvularia blight in agrostis stolonifera in South of PortugalPublication . Coelho, Luísa; Borrero, C.; Bueno-Pallero, Francisco Angel; Guerrero, Carlos; Fonseca, Filomena; Reis, Mário; Avilés, M.; Dionísio, LídiaAlgarve region (Portugal) has nearly 40 golf courses with a significant economic impact. Summer surveys on 10 golf courses detected an unknown disease on one course in 2009 and on another course in 2012 and 2013 at 29 to 30°C daily average. The second course had symptoms on about 25% of the turf of two putting greens. Diseased bentgrass (Agrostis stolonifera L.) had a green dappled pattern with irregular patches of turfgrass on yellowed leaves. Prior to decaying, affected leaves turned brown and then gray. Crown and leaf sheath infections resulted in dark brown dry rot. No lesions were observed on the roots. Leaves were surface disinfected with 5% commercial bleach (0.225% sodium hypochlorite) and cultured on potato dextrose agar (PDA). Ten fungal colonies grew from the leaf tissue, and brown mycelia, conidiophores, and conidia were observed under a microscope. Conidia were ventricose pyriform, mostly abruptly curved, 20 to 36 µm (30 µm, SD = 4) × 7 to 12 µm (10.5 µm, SD = 1.3) (n = 50), predominantly three-septate, with a prominent hilum and enlarged and darkened central cells. Colonies grown on PDA were black-brown with a black reverse side. Conidia differed in size, 15.4 to 24.6 µm (19.99 µm, SD = 3.00) × 6 to 11 μm (8.68 µm, SD = 1.54) (n = 50) and morphology (cylindrical or slightly curved). These characteristics were consistent with Curvularia trifolii (Kauffm.) Boedijn. (Ellis 1971; Falloon 1976; Khadka 2016). Species identification of the representative isolate A2 1.12 was confirmed by analysis of nucleotide sequences of the ITS1-5.8S-ITS2 region using primers ITS1 and ITS4 (White et al. 1990) and GPDH gene region with primer set gpd (Koike et al. 2013). BLAST searches of GenBank showed a high similarity of the isolate ITS sequence (MG029439) to the reference sequence JN712458 of C. trifolii (99% identity) and GPDH sequence (MK570108) with LT715803.1 (97.88% identity). The maximum likelihood phylogenetic tree showed that our isolate clustered with C. trifolii. The pathogenicity assay of this isolate was conducted in greenhouse on A. stolonifera ‘Penncross’. The isolate was grown on PDA (25°C, 10 days). Five pots (100 ml) were filled with a sand and peat mix (9:1 v/v) with 0.06 g of seeds per pot, covered with a fine sand layer. Turfgrass was cut once a week beginning 2 weeks after seeding and was fertigated with 0.5 g/liter of Peter’s foliar feed (27 + 15 + 12; N + P2O5 + K2O; and micronutrients; Scotts, Heerlen, The Netherlands). To obtain a conidial suspension for inoculation, cultured plates were scraped with a sterilized spreader and water. The suspension was filtered through a sterile gauze. Conidia were counted under a microscope (400×) with a hemocytometer. The suspension was adjusted to 8 × 103 conidia/ml, and 10 ml was sprayed per pot. Pots maintained humidity for 2 days under microtunnels. The first disease symptoms appeared 3 days after inoculation. Bentgrass from the five pots developed Curvularia blight and rotted crown symptoms. Control plants (five pots treated with water) did not display symptoms. This trial was repeated once. On PDA, C. trifolii was reisolated from leaf lesions and morphologically identified, confirming Koch’s postulates. Ellis (1971) referred to the presence of C. trifolii in Portugal, but no region, symptom description, or grass species was detailed. Sivanesan (1987) reported C. trifolii in Portugal only on Lolium multiflorum. Therefore, this is the first report of C. trifolii in Algarve, affecting A. stolonifera. This disease can increase maintenance costs in greens in this area.
- Use of cork residues to control turfgrass diseasesPublication . Coelho, Luísa; Dionísio, Lídia; Reis, Mário; Guerrero, CarlosThe worldwide increase in agricultural and industrial production has created environmental problems. Economic and environmental benefits can be gathered solving a problem of the agroindustry by applying their sub products to soil. The compromise to decrease the use of pesticides and fertilizers, which may be hazardous, has provided opportunities for the development of new sustainable crop management practices. From several strategies to enhance the use of organic matter in agriculture, one has been the use of composts of different mixtures of raw materials, from different agroindustry processes or the use of these raw material (agroindustry residues) directly without any treatment. The incorporation of these products to the soil and its application to the crops proved to be an interesting pathway to apply effective beneficial microorganisms for the crops and for the ecosystems globally. This strategy showed to achieve reasonable crops yields and suppressive effects on phytopathogenic microorganisms. Several microorganisms have been associated to cork throughout tree life and in the end products1, such as Trichoderma pseudoconingii, T. viride, Endothiella gyrosa, Mucor hiemalis, Rhysopus sp., Penicillium sp., Cytospora sp., Dichomera sp., Acremonium sp., Glyocladium sp., Botrytis silvatica, and Pestalotia sp. Considering the potential of these microorganisms, a study was carried out at the University of Algarve to identify the presence of beneficial microorganisms in cork residues and to evaluate, in vitro, their antagonistic effect against several fungi turfgrass diseases.
- The first detection of Leishmania major in naturally infected Sergentomyia minuta in PortugalPublication . Campino, Lenea; Cortes, Sofia; Dionisio, Lidia; Neto, Luis; Afonso, Maria Odete; Maia, CarlaPhlebotomine sandflies of the genus Sergentomyia are widely distributed throughout the Old World. It has been suggested that Sergentomyia spp are involved in the transmission of Leishmania in India and Africa, whereas Phlebotomus spp are thought to be the sole vectors of Leishmania in the Old World. In this study, Leishmania major DNA was detected in one Sergentomyia minuta specimen that was collected in the southern region of Portugal. This study challenges the dogma that Leishmania is exclusively transmitted by species of the genus Phlebotomus in the Old World.
- Culture media performance on the detection of actinomycetes from compostsPublication . Coelho, Luísa; Reis, Mário; Dionísio, LídiaIn this study we evaluated the performance of six culture media on the detection of actinomycetes that were present in composts of agro-industrial wastes from the Algarve region. The composts were produced with orange wastes, olive pomace and grass clippings, in the proportion of 2:1:1 of volume. Two compost piles were built with different ventilation systems, one with forced ventilation and the other with mechanical turning and natural ventilation. In order to quantify the population of actinomycetes, different growth media containing antibiotics were tested and one culture medium containing only half of the concentration of the Plate Count Agar (½ PCA) was also tested. The incubation took place at two temperatures, 25º and 55ºC. Different results were obtained for the enumerations from the culture media. The population of actinomycetes achieved higher values when incubated at 55ºC and when the samples were inoculated in the ½ PCA culture medium. Thus, the antibiotics showed no beneficial effect in the tested culture media. The results suggest the use of the ½ PCA culture medium as the most adequate in order to count the bacterial populations in these samples. This medium is also the less expensive and the one that showed the fastest bacterial growth.
- Presença da sarna da batata-doce (Monilochaetes infuscans) em Portugal continentalPublication . Duarte, Amilcar; Coelho, Luísa; Louro, Pedro; Costa, João; Dionísio, LídiaA batata-doce é uma cultura oriunda do continente americano, que está presente no sul de Portugal desde há vários séculos, fazendo parte das tradições gastronómicas desta zona do país. Tradicionalmente, a batata-doce fazia parte de um sistema de rotação de culturas, alternando com cereais e leguminosas. Nessas condições, a cultura não apresentava problemas fitossanitários, não carecendo, portanto, de aplicação de nenhum pesticida. Nos últimos anos tem havido um incremento do interesse pelo produto e um aumento da produção, com cultivo de batata-doce nas mesmas parcelas em anos seguidos. Este abandono dos sistemas de rotação e a importação de plantas de outras zonas produtoras, sem os devidos cuidados fitossanitários, levaram ao aparecimento de várias doenças e pragas que começam a produzir danos significativos. A introdução de um sistema de produção de material vegetal de qualidade que diminua os riscos de propagação de doenças e pragas pode minimizar o efeito negativo do abandono das boas práticas agrícolas de outrora. De entre as doenças que atacam a cultura, a sarna da batata-doce é uma das mais disseminadas, estando presente em muitas zonas produtoras. Em Portugal, esta doença só tinha sido identificada nos Açores.Em 2016 a doença foi detetada em plantações de batata-doce do sudoeste de Portugal continental. Amostras de batata-doce com sintomas característicos da doença foram recolhidas numa exploração agrícola e analisadas na Universidade do Algarve. Foi feita uma inoculação em meio de cultura PDA, adequado para o crescimento de fungos, e incubou-se a 25 ± 2ºC. As colónias de fungos formadas foram repicadas para PDA com o objectivo de se obter cultura pura. As características culturais macroscópicas e microscópicas testemunham a presença de Monilochaetes infuscans Ell. & Halst. ex Harter. Este fungo causa lesões acastanhadas na superfície da batata-doce, desvalorizando comercialmente o produto e acarretando perdas económicas significativas.
- Effect of packaging technology on microbiological and sensory quality of a cooked blood sausage, Morcela de Arroz, from Monchique region of PortugalPublication . Pereira, J; Dionísio, Lídia; Patarata, L.; Matos, T. J. S.Morcela de Arroz (MA), a popular Portuguese blood sausage, with high pH and water activity (a(w)), is traditionally commercialized without preservatives and unpacked. This study evaluated the best packaging solution to extend MA shelf life stored at 4 +/- 1 degrees C for 44 days: without packaging (WP), vacuum (VP) and modified atmosphere packaging (MAP) (80% CO2; 20% N-2). Mesophilic (MTVC), psychrotrophic (PTVC), lactic acid bacteria (LAB), pseudomonads, molds and yeasts, Enterobacteriaceae, Listeria monocytogenes, Salmonella spp., Bacillus cereus, Clostridium perfringens, sensory properties, pH, moisture and aw were studied. Moisture and a(w) decreased (p < 0.05) in WP. pH decreased in WP and MAP during storage. MTVC and PTVC counts increased to values around 7 log CFU/g at 44 days of storage. LAB and Enterobacteriaceae counts were higher (p < 0.05) in VP. Pseudomonads were inhibited (p < 0.05) by MAP after 8 days of storage. Sensory parameters were affected (p < 0.05) by packaging and storage time. Globally, MAP performed better. (C) 2014 Elsevier Ltd. All rights reserved.
- Trichoderma gamsii as a biological control agent of turfgrass diseasesPublication . Coelho, Luísa; Dionísio, Lídia; Bueno-Pallero, Francisco; Reis, Mário; Duarte, J.; Guerrero, CarlosGolf is a growing and economically important activity in Portugal with direct and indirect incomes respectively over 350 and 1.450 million of euros, corresponding nearly 1.25% of the Gross National Product. The correct maintenance of lawns in a sustainable manner is required. Sport lawns are quite susceptible to soil-borne diseases1 , which cause enormous economic losses, making environmental friendly disease control methods a practice to develop. The increasing interest regarding environment and public health protection have been increased the search for alternatives, leading researchers to seek strategies to reduce the use of synthetic products, such as fertilizers and pesticides2 . Also, the European legislation is directing the reduction of pesticides3 , facing itself towards more sustainable policies.