Ciência Rural

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10366

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2011 - 20184

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Assunto: search.filters.subject.Biotecnologia

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Agora exibindo 1 - 4 de 4
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    2- Isopentenyladenine in the induction of direct somatic embryogenesis capacity of Coffea arabica L.
    (Universidade Federal de Santa Maria, 2018) Alves, Ivanilda dos Santos; Carmazini, Valéria Cristina Barbosa; Santos, Cosme Damião dos; Almeida, Julieta Andrea Silva de
    This study evaluated the effect of different concentrations of 2-isopentenyladenine (2-iP) on the direct somatic embryogenesis capacity of the Mundo Novo cultivar of Coffea arabica. Leaf explants were cultivated with half the MS salt concentration and the addition of sucrose (20gL-1 ) and 2-iP (0; 2.5; 5; 7.5 and 10μM). The 2-iP doses of 7.5 and 10μM produced the greatest responses with respect to the percentage of explants with embryogenic structures and the size of the embryogenic structures. However, the greatest production of somatic embryos occurred on the explants treated with 10μM of 2-iP, followed by 7.5μM, whereas their production was absent or reduced with 0 and 5μM, respectively.
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    Biotecnologia aplicada ao melhoramento genético do cafeeiro
    (Universidade Federal de Santa Maria, 2011-05) Morais, Tâmara Prado de; Melo, Benjamim de
    O melhoramento genético do cafeeiro mediante técnicas convencionais é trabalhoso e demorado. A biotecnologia oferece estratégias alternativas para auxiliar na multiplicação e no desenvolvimento de novas variedades com resistência a estresses bióticos e abióticos, melhor qualidade de bebida e maturação mais uniforme dos frutos. As técnicas de cultura de tecidos têm possibilitado a obtenção de grande número de plantas e a garantia da uniformidade genética do material. O emprego de marcadores moleculares, principalmente através da seleção assistida, facilitou o rápido progresso do melhoramento genético da cultura, assim como a transformação genética, via cultura e fusão de protoplastos, biobalística ou mediada por Agrobacterium sp. Esta revisão objetiva sumarizar o histórico, situação atual e perspectivas da biotecnologia no melhoramento genético do cafeeiro.
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    Calli induction in leaf explants of coffee elite genotypes
    (Universidade Federal de Santa Maria, 2011-03) Rezende, Juliana Costa de; Carvalho, Carlos Henrique Siqueira de; Pasqual, Moacir; Santos, Ana Carolina Ramia; Carvalho, Stephan Malfitano de
    Three experiments were carried out with the objective of achieving high effectiveness in calli induction from high heterozygosis leaf explants of Coffea arabica through indirect somatic embryogenesis. A randomized-block design in a 2x5 factorial arrangement made up of two media [BOXTEL & BERTHOULY (1996) and TEIXEIRA et al. (2004)] and five C. arabica genotypes were used in the first experiment. In the second experiment the embryogenic calli production potential was evaluated in ten genotypes. Each of them was considered as a treatment. In the third experiment the variations in both 2.4-D (2.5 e 20μM) and 2-iP (2.5 e 20μM) concentrations in TEIXEIRA et al. (2004) medium and secondary media were evaluated. Crops were kept in a growth room under darkness, at 25±2 o C. The medium described by TEIXEIRA et al (2004) was found to be superior when compared to that described by BOXTEL & BERTHOULY (1996) in the 2.2 and 7.2 genotypes. An opposite behavior was noticed in 4.2 genotype, that is, BOXTEL & BERTHOULY (1996) had medium superiority. Both 3.0 and 5.0 genotypes had the same behavior in both media studied, which shows that the somatic embryo production depends on the genotype. Calli induction depends on the 2-iP and 2.4 D ratio. The 20.0μM of 2.4-D and 20.0μM of 2-iP combination caused the highest embryogenic calli induction rate.
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    Morphological characteristics and cell viability of coffee plants calli
    (Universidade Federal de Santa Maria, 2014-04) Pádua, Marlúcia Souza; Paiva, Luciano Vilela; Silva, Luciano Coutinho da; Livramento, Kalynka Gabriella do; Alves, Eduardo; Castro, Ana Hortência Fonseca
    The a im of this research was to characterize and compare two types of calli from leaf explants of Coffea arabica (cultivar Catiguá). Cells of different types of callus were successfully characterized regarding viability and internal and external morphological characteristics. It was obtained two morphologically distinct types of callus: (i) yellow friable and (ii) transparent watery. The yellow friable calli showed higher cell viability and embryogenic characteristics. Scanning and transmission electron microscopy showed embryogenic characteristics in cells of the yellow friable calli evidenced by the presence of small and isodiametric cells, while transparent watery calli showed elongated cells and large cytoplasm vacuolization.