662 research outputs found

    Biovar-specific and broad-spectrum sources of resistance to bacterial wilt (Ralstonia solanacearum) in Capsicum.

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    Made available in DSpace on 2018-06-07T01:05:13Z (GMT). No. of bitstreams: 1 c8128f423e80663f.pdf: 70390 bytes, checksum: bb981edb7f455c3dc52a1c45ffabd080 (MD5) Previous issue date: 2005-03-29bitstream/item/178255/1/c8128f42-3e80-663f.pd

    Breeding biofortified cowpea lines for semi-arid tropical areas by combining higher seed protein and mineral levels.

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    One strategy to mitigate human malnutrition in semi-arid areas is to increase the protein and mineral content of cowpea cultivars. Total seed protein, potassium, calcium, iron, zinc, and sodium contents were quantified in elite cowpea lines, with the aim to develop cultivars that had improved levels of these nutrients. Eighty-seven F6 lines derived from 6 crosses were evaluated under rain-fed conditions in Petrolina, Brazil. Seed protein and mineral content were quantified by the micro-Kjeldhal method and in an atomic absorption spectrophotometer, respectively. Statistical analyses were estimated for all traits, including grain yield. Significant differences were observed for all characteristics. Seed protein content ranged from 22.5 to 34.1%, potassium levels ranged from 20,200 to 27,000 ppm, and calcium levels ranged from 410 to 6260 ppm. Iron content ranged from 36.5 to 137 ppm, while zinc content ranged from 36 to 58 ppm and sodium content ranged from 29.2 to 88 ppm. Simple correlation coefficient values indicated that selection for high protein and mineral content does not affect grain yield. These results demonstrate that it higher levels of protein and essential minerals

    Eficácia relativa de porta-enxertos comerciais de tomateiro no controle da murcha-bacteriana.

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    O objetivo deste trabalho foi avaliar, em casa de vegetação, os níveis de resistência à murcha-bacteriana dos principais porta-enxertos comerciais de tomateiro, levando em conta a variabilidade patogênica de um conjunto de isolados de R. solanacearum

    Genetic control and transgressive segregation of zinc, iron, potassium, phosphorus, calcium, and sodium accumulation in cowpea (Vigna unguiculata) seeds.

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    Cowpea crop, through combining a range of essential minerals with high quality proteins, plays an important role in providing nutritional security to human population living in semi-arid regions. Studies on genetics of biofortification with essential minerals are still quite scarce, and the major objective of the present study was to provide genetic information on development of cowpea cultivars with high seed mineral contents. Genetic parameters heritability and minimum number of genes were estimated for seed accumulation of zinc (Zn), iron (Fe), calcium (Ca), phosphorus (P), potassium (K), and sodium (Na). Generation mean and variance analyses were conducted using contrasting parental lines, F1, F2, and backcross populations derived from IT97K-1042-3 x BRS Tapaihum and IT97K-1042-3 x Canapu crosses. High narrow-sense heritability (h2) values were found for accumulation of Fe (65-86%), P (74-77%), and K (77-88%), whereas moderate h2 values were observed for accumulation of Ca (41-56%), Zn (51-83%), and Na (50-55%) in seeds. Significant additive genetic effects as well whereas epistasis was important genetic component in Zn content. The minimum number of genes controlling the accumulation of minerals ranged from two (K) to 11 (P). Transgressive segregation was observed in F2 populations of both crosses for all minerals analyzed. The results suggest that, although under either oligogenic or polygenic control, the seed content of these six minerals in cowpea can be improved via standard breeding methods largely used for self-pollinated crops

    Doenças da berinjela no Brasil.

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    bitstream/item/57202/1/CT-97.pd

    Mancha-de-septória: doença limitante do tomateiro no período de chuvas.

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    bitstream/item/103062/1/cot-37.pd

    The spectral geometry of the canonical Riemannian submersion of a compact Lie Group

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    Let G be a compact connected Lie group which is equipped with a bi-invariant Riemannian metric. Let m(x,y)=xy be the multiplication operator. We show the associated fibration m mapping GxG to G is a Riemannian submersion with totally geodesic fibers and we study the spectral geometry of this submersion. We show the pull back of eigenforms on the base have finite Fourier series on the total space and we give examples where arbitrarily many Fourier coefficients can be non-zero. We give necessary and sufficient conditions that the pull back of a form on the base is harmonic on the total space
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