27 research outputs found

    Early development of Moniliophthora perniciosa basidiomata and developmentally regulated genes

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    <p>Abstract</p> <p>Background</p> <p>The hemibiotrophic fungus <it>Moniliophthora perniciosa </it>is the causal agent of Witches' broom, a disease of <it>Theobroma cacao</it>. The pathogen life cycle ends with the production of basidiocarps in dead tissues of the infected host. This structure generates millions of basidiospores that reinfect young tissues of the same or other plants. A deeper understanding of the mechanisms underlying the sexual phase of this fungus may help develop chemical, biological or genetic strategies to control the disease.</p> <p>Results</p> <p>Mycelium was morphologically analyzed prior to emergence of basidiomata by stereomicroscopy, light microscopy and scanning electron microscopy. The morphological changes in the mycelium before fructification show a pattern similar to other members of the order <it>Agaricales</it>. Changes and appearance of hyphae forming a surface layer by fusion were correlated with primordia emergence. The stages of hyphal nodules, aggregation, initial primordium and differentiated primordium were detected. The morphological analysis also allowed conclusions on morphogenetic aspects. To analyze the genes involved in basidiomata development, the expression of some selected EST genes from a non-normalized cDNA library, representative of the fruiting stage <it>of M. perniciosa</it>, was evaluated. A macroarray analysis was performed with 192 selected clones and hybridized with two distinct RNA pools extracted from mycelium in different phases of basidiomata formation. This analysis showed two groups of up and down-regulated genes in primordial phases of mycelia. Hydrophobin coding, glucose transporter, Rho-GEF, Rheb, extensin precursor and cytochrome p450 monooxygenase genes were grouped among the up-regulated. In the down-regulated group relevant genes clustered coding calmodulin, lanosterol 14 alpha demethylase and PIM1. In addition, 12 genes with more detailed expression profiles were analyzed by RT-qPCR. One aegerolysin gene had a peak of expression in mycelium with primordia and a second in basidiomata, confirming their distinctiveness. The number of transcripts of the gene for plerototolysin B increased in reddish-pink mycelium and indicated an activation of the initial basidiomata production even at this culturing stage. Expression of the glucose transporter gene increased in mycelium after the stress, coinciding with a decrease of adenylate cyclase gene transcription. This indicated that nutrient uptake can be an important signal to trigger fruiting in this fungus.</p> <p>Conclusion</p> <p>The identification of genes with increased expression in this phase of the life cycle of <it>M. perniciosa </it>opens up new possibilities of controlling fungus spread as well as of genetic studies of biological processes that lead to basidiomycete fruiting. This is the first comparative morphologic study of the early development both <it>in vivo </it>and <it>in vitro </it>of <it>M. perniciosa </it>basidiomata and the first description of genes expressed at this stage of the fungal life cycle.</p

    Qualidade de carnes provenientes de cortes da carcaça de cordeiros e de ovinos adultos Quality of meats from cuts of lamb and adult sheep carcasses

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    Com o objetivo de estudar as características qualitativas da carne de ovinos de diferentes categorias quanto aos músculos dos cortes da carcaça (paleta, lombo e perna), utilizaram-se 18 ovinos ½ Ile de France ½ Ideal (seis cordeiros não-castrados, seis ovelhas de descarte e seis machos adultos castrados). Os animais foram criados em pasto de capim-tifton 85 e receberam suplementação (concentrado). Os cordeiros foram abatidos aos 32 kg, com aproximadamente 5 meses de idade, e as ovelhas e os machos adultos castrados, com 55 kg e aos 60 meses de idade. Não houve diferenças nos valores de pH 45 minutos e pH 24 horas entre as categorias animais e nos músculos dos cortes da carcaça. A idade de abate influenciou a luminosidade da carne de todos os músculos. O teor de vermelho não diferiu entre os animais adultos, mas foi superior aos valores obtidos na carne dos cordeiros. A carne de animais adultos é mais escura que a de cordeiros. As perdas por cocção no músculo Triceps brachii são maiores que no Longissimus lumborum e Semimembranosus. Os valores de pH e a capacidade de retenção de água são similares entre as categorias animais.<br>Eighteen ½ Ile de France ½ Polwarth sheep (6 no castrated lambs, 6 discarded ewes and 6 discarded wethers) were used to evaluate qualitative traits of meat from different categories of sheep for muscle cuts (shoulder, loin and leg). The animals were raised in grazing system with tifton-85 pastures and supplemented with concentrate. Lambs were slaughtered at 32 kg body weight, close to 5 months of age. Ewes and wethers were slaughtered with 55 kg and 60 months of age. There were no differences in pH45mim and pH24h values among different animal categories and muscles of carcass cuts. There was difference in meat luminosity between lambs and adult animals, considering all the evaluated muscles. The red level did not differ between adult categories, but it was higher than values observed in lambs. In conclusion, meat from adult animals was darker than lamb meat. Considering all animal categories, cooking losses were higher in Triceps brachii compared to Longissimus lumborum and Semimembranosus. Values of pH and water retention capacity were similar among animal categories

    Qualidade dos frutos de genótipos de tomateiro do banco de germoplasma de hortaliças da Universidade Federal de Viçosa

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    Foi avaliada a qualidade dos frutos de 29 acessos de tomateiro do Banco de Germoplasma de Hortaliças (BGH-UFV) e de três cultivares comerciais, Santa Clara, Débora Plus e Fanny. As variáveis avaliadas foram: sólidos solúveis (SS), acidez titulável (AT), pH e relação SS/AT. Foi observada, para os acessos, variação significativa das características avaliadas, com exceção do pH. Os acessos BGH700, BGH2000, BGH2008, BGH2013, BGH2014 e BGH2017 destacaram-se no que se refere ao teor de SS, tendo estes sido superiores em 4,2 ºBrix aos dos cultivares comerciais. Com relação à acidez titulável, os acessos BGH2013, BGH2019, BGH2020 e BGH2033 apresentaram os maiores valores, com acidez acima de 0,57%. Os cultivares comerciais foram alocados no grupo de menor acidez, com valores inferiores a 0,46%. Para a relação SS/AT, destacaram-se os acessos BGH700, BGH2000, BGH2008 e o cultivar comercial Débora Plus com valores de 11,1; 11,9; 10,9; e 10,0, respectivamente.Fruit quality of 29 tomato accesses from the Vegetable Germplasm Bank of the Universidade Federal de Viçosa and three commercial cultivars, Santa Clara, Débora Plus and Fanny were evaluated for the characteristics soluble solids (SS), acidity (AT), pH and SS/AT ratio (flavor fruits indicator). The accesses showed significant variation for the evaluated characteristics, except for the pH. The accesses BGH-700, BGH-2000, BGH-2008, BGH-2013, BGH-2014 and BGH-2017 stood out for the SS content, which were higher than 4.2 ºBrix and the SS content of the commercial cultivars. Acidity of the accesses BGH-2013, BGH-2019, BGH-2020 and BGH-2033 was higher, above 0.57%. The commercial cultivars were classified into the group with the lowest acidity, with values under 0.46%. The accesses BGH-700, BGH-2000, BGH-2008 and the commercial cultivar Débora Plus stood out for the SS/AT ratio, with values of 11.1, 11.9 and 10.9, and 10.0, respectively

    Desempenho de cordeiros Santa Inês alimentados com dietas completas contendo feno de maniçoba Performance of Santa Inês lambs fed total mixed rations containing different ratios of concentrate to ceara rubbertree hay

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    Avaliou-se o desempenho de cordeiros alimentados com dieta completa formulada com diferentes proporções de feno de maniçoba. Foram utilizados 32 animais Santa Inês machos, não-castrados (idade inicial de 70 dias e peso vivo de 16,02±2,37 kg), distribuídos em delineamento inteiramente casualizado, com quatro tratamentos e oito repetições. As dietas foram constituídas de concentrado e feno de maniçoba (FM) nas proporções de 20, 40, 60 e 80%. As proporções de feno na dieta não influenciaram os consumos de MS, PB e CT, cujas médias diárias foram 1,214; 0,201 e 0,816 kg, respectivamente. Os níveis de feno tiveram efeito linear positivo sobre o consumo de FDN e efeito linear negativo sobre o consumo de EM e CNF. O ganho de peso diário foi afetado pelos níveis de feno na dieta, apresentando médias de 290,84; 293,62; 253,35 e 208,48 g, respectivamente, para as dietas com 20, 40, 60 e 80% de feno de maniçoba. As dietas influenciaram a conversão (Y = 3,332+0,028x) e a eficiência alimentar (Y = 0,280,0013x). Pela análise econômica, observaram-se relações custo:benefício de 1,49; 1,57; 1,69 e 1,84 para os níveis de 20, 40, 60 e 80% de feno de maniçoba na dieta. O custo operacional efetivo por quilograma de carcaça produzida foi de R3,68;R 3,68; R 3,49; R3,23eR 3,23 e R 2,98, respectivamente, para as dietas com 20, 40, 60 e 80% de feno. A inclusão de 80% de feno de maniçoba em dietas completas possibilitou a obtenção de desempenho satisfatório dos cordeiros e melhor retorno financeiro.<br>The objective of this trial was to investigate the effect of different dietary ratios of concentrate (C) to ceara rubbertree hay (CRH; Manihot Glaziovii Muell. Arg.) on performance of lambs. Thirty two intact Santa Inês lambs averaging 70 days of age and 16.02±2.371 kg of body weight were fed one of the following four treatments as total mixed rations: 80C:20CRH (diet A), 60C:40CRH (diet B), 40C:60CRH (diet C), or 20C:80CRH (diet D) in a completely randomized design (eight repetitions/treatment). Increasing levels of CRH in the diet had no significant effect on the intakes of dry matter, crude protein, and total carbohydrates which averaged 1.214, 0.201, and 0.816 kg/day, respectively. However, intake of neutral detergent fiber increased linearly while the opposite was observed for intakes of metabolizable energy and nonfiber carbohydrates by increasing the proportion of CRH in the diet. The average daily gain was significantly affected by the different dietary ratios of C:CRH averaging 290.84, 293.62, 253.35, and 208.48 g/d, respectively, for diets A, B, C, and D. Significant linear effects were also observed for feed conversion (Y = 3.332 + 0.028x) and feed efficiency (Y = 0.28-0.0013x) when the proportion of CRH was increased from diet A to diet D. The profit:cost ratio and the cost per kg of carcass averaged, respectively, 1.49, 1.57, 1.69, and 1.84 and R3.68,R3.68, R3.49, R3.23,andR3.23, and R2.98 with 20, 40, 60 and 80% of CRH hay in the diet. It can be concluded that the C:CRH ratio of 20:80 (diet D) resulted in satisfactory performance and improved income of Santa Inês lambs
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