Embrapa Cenargen

Brasília, Brazil

Embrapa Cenargen

Brasília, Brazil
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Bueno dos Reis Jr F.,Embrapa Cerrados | Simon M.F.,Embrapa Cenargen | Gross E.,University Estadual Of Santa Cruz | Boddey R.M.,Embrapa Agrobiologia | And 15 more authors.
New Phytologist | Year: 2010

•An extensive survey of nodulation in the legume genus Mimosa was undertaken in two major biomes in Brazil, the Cerrado and the Caatinga, in both of which there are high degrees of endemicity of the genus.•Nodules were collected from 67 of the 70 Mimosa spp. found. Thirteen of the species were newly reported as nodulating. Nodules were examined by light and electron microscopy, and all except for M. gatesiae had a structure typical of effective Mimosa nodules. The endosymbiotic bacteria in nodules from all of the Mimosa spp. were identified as Burkholderia via immunolabelling with an antibody against Burkholderia phymatum STM815.•Twenty of the 23 Mimosa nodules tested were shown to contain nitrogenase by immunolabelling with an antibody to the nitrogenase Fe- (nifH) protein, and using the δ15N (15N natural abundance) technique, contributions by biological N2 fixation of up to 60% of total plant N were calculated for Caatinga Mimosa spp.•It is concluded that nodulation in Mimosa is a generic character, and that the preferred symbionts of Brazilian species are Burkholderia. This is the first study to demonstrate N2 fixation by beta-rhizobial symbioses in the field. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Pozzobon M.T.,Embrapa Cenargen | de Souza K.R.R.,Embrapa Hortalicas | de Carvalho S.I.C.,Embrapa Hortalicas | Reifschneider F.J.B.,Embrapa Hortalicas
Horticultura Brasileira | Year: 2011

Twelve lines of pepper, from different groups {Jalapeño (CNPH 2862, CNPH 2864), Dedo-de-Moça (CNPH 1397, CNPH 0039, CNPH 0053), Cambuci (CNPH 0283), Peixe-Boi (CNPH 0434), Falsa Cumari (CNPH 3761), Bode Vermelha (CNPH 3773), Biquinho Doce (CNPH 3870), Tabasco (CNPH 3000) and Malagueta (CNPH 2869) had their meiotic behavior and the estimation of pollen viability analyzed with the aim of indicating potentially fertile material for the Capsicum breeding program. Conventional analysis by staining revealed a slightly irregular behavior during microsporogenesis for the majority of lines: the meiotic index (MI) and pollen viability were over 90%, therefore considered meiotically stable. The main abnormalities observed were chromosome stickiness, unoriente chromosomes, laggards, bridges, micronuclei, microcytes and cytomixis. Three lines (CNPH 0283, CNPH 3000 and CNPH 3773) showed lower pollen viability, 77, 66 and 58% respectively. The lower pollen viability in CNPH 0283 was associated with higher frequency of irregularities and consequently the low MI (77%). The findings of the present manuscript confirm the importance of the cytological analyzes as a useful tool in selecting of lines meiotically stable and potentially fertile enabling a better planning of seed production of promising cultivars.

Ramiro D.,CIRAD - Agricultural Research for Development | Jalloul A.,Damascus University | Petitot A.-S.,CIRAD - Agricultural Research for Development | Grossi de Sa M.F.,Embrapa Cenargen | And 2 more authors.
Tree Genetics and Genomes | Year: 2010

In plants, WRKY proteins are a group of transcription factors existing as a gene superfamily that play important roles in regulation of defense response pathways. To assess the diversity of this protein family in coffee (Coffea spp.), data mining methods were used on a set of around 200,000 coffee expressed sequence tags. A total of 53 different putative WRKY genes were obtained, but only 22 unigenes encoding a protein with a WRKY domain were identified, eight of which are supported by full-length cDNA sequences. Alignment of WRKY domain sequences of the coffee unigenes and 72 Arabidopsis thaliana WRKY genes showed that the 22 coffee WRKY members were distributed among the main A. thaliana WRKY subgroups and shared conserved peptide domains. To assess the involvement of WRKY genes in coffee defense response pathways, their expression was analyzed under biotic (nematode and rust fungus infection), hormonal (salicylic acid, methyl-jasmonate), and wounding treatments, leaf senescence, and fruit development. Five members of WRKY groups IId and III were regulated only by pathogens and hormone treatments. Although a significant correlation of WRKY genes expression after MeJA and rust treatments was observed, expression of coffee genes involved in JA biosynthesis and lipoxygenase (EC activity assays did not support the involvement of JA in the early coffee resistance responses to the rust pathogen. The five WRKY transcription factor members identified might play important roles as regulators of pathogen resistance responses and could be useful for improving coffee tolerance to various biotic stresses. © 2010 Springer-Verlag.

de Andrade Souza L.,State University of Southwest Bahia | Carneiro P.L.S.,State University of Southwest Bahia | Malhado C.H.M.,State University of Southwest Bahia | Paiva S.R.,Embrapa Cenargen | And 2 more authors.
Revista Brasileira de Zootecnia | Year: 2011

The objective of the present study was to evaluate non-linear models to describe Morada Nova sheep herds raised in the State of Bahia and, after defining the best suiting model, calculate the rate of absolute growth and evaluate the influence of environmental factors (sex and type of parturition) on the curve parameters. Weighting data from 40 sheep from birth up to 385 days of age were used. The non-linear models used were: Brody, Von Bertalanffy, Richards, Logistic and Gompertz. Von Bertalanffy, Brody and Richards models presented the best adjustments and were equivalent to explain the growth of the analyzed animals. A remarkable drop in the absolute growth rate was observed after weaning, suggesting that a proper diet should be implemented to supply the nutritional demands of the animals at this stage. The environmental effects (sex and type of parturition) have significantly influenced the maturity rate (k), but only the sex of the lamb affected weight at maturity (A). Animals born from single parturition proved to be heavier than twins which, in turn, presented compensatory gain. The growth of males was higher than of females and the latter presented more precocity than males. Estimated correlation between parameters A and k was negative (-0.65) for the Von Bertalanffy model and for the Brody and Richards models (-0.71) indicating that the most precocious animals are less likely to reach elevated weights when adults. © 2011 Sociedade Brasileira de Zootecnia.

Bontemps C.,University of York | Elliott G.N.,Macaulay Institute | Simon M.F.,Embrapa Cenargen | Dos Reis Junior F.B.,Embrapa Cerrados | And 8 more authors.
Molecular Ecology | Year: 2010

Burkholderia has only recently been recognized as a potential nitrogen-fixing symbiont of legumes, but we find that the origins of symbiosis in Burkholderia are much deeper than previously suspected. We sampled 143 symbionts from 47 native species of Mimosa across 1800 km in central Brazil and found that 98% were Burkholderia. Gene sequences defined seven distinct and divergent species complexes within the genus Burkholderia. The symbiosis-related genes formed deep Burkholderia-specific clades, each specific to a species complex, implying that these genes diverged over a long period within Burkholderia without substantial horizontal gene transfer between species complexes. © 2009 Blackwell Publishing Ltd.

Valencia J.W.A.,University of the Atlantic | De Sa M.F.G.,Embrapa Cenargen | Jimenez A.V.,University of Caldas
Protein and Peptide Letters | Year: 2014

The enzymatic activity of leucine aminopeptidase (EC from the intestinal tract of sugarcane giant borer (Telchin licus licus) was assayed by using a simple and sensitive spectrophotometric assay that uses L-leucyl-2-naphthylamide as substrate. In this assay, L-leucyl-2-naphthylamide is hydrolyzed to produce 2-naphthylamine and Lleucine. The product 2-naphthylamine reacts with Fast Black K and can be monitored using a continuous spectrophotometric measurement at 590 nm. The data on the kinetic parameters indicates that the Km for the L-leucyl-2-naphthylamide at pH 7.0 was found to be lower than those found for other LAP substrates. The Km and Vmax for the LAP were determined to be 84.03 βM and 357.14 enzymatic units mg-1, respectively. A noticeable difference of LAP activity between the two insect orders tested was observed. This method could be used to screen for natural LAP inhibitors. © 2014 Bentham Science Publishers.

One of the main barriers for cassava genetic breeding is the difficulty for early selection of superior individuals within the first breeding generations. Therefore, the aim of the present work was to estimate the phenotypic correlations among agronomic characters in a segregating population of sweet cassava, within the vegetative and sexual generation, and between two, in order to obtain phenotypic indicators that increase the efficiency of selection of superior genotypes in segregating populations. The segregating population from the cross IAC 576-70 and BRS Japonesa was used to estimate the phenotypic correlation among seven agronomic traits evaluated individually within the sexual and clonal propagation populations and between the two populations. No trait within the generation of sexual propagation had high correlation with the root yield in the generation of clonal propagation. This weak association among the traits within the seed-propagated generation and their production potential, during clonal propagation, revealed the difficulty to accurately and early predict the production potential of a genotype using phenotypic evaluations, especially when evaluating it from seeds. Nevertheless, the high correlation between the cooking time in the seed-propagated generation with the generation of clonal propagation is a parameter to be considered for the early selection of clones with shorter cooking time.

Viana J.H.M.,Embrapa Cenargen | Hinduja S.,University of Manchester | Bartolo P.J.S.,University of Manchester
Virtual and Physical Prototyping | Year: 2016

The quantity and quality of phenotypic data recovered from farm animals became a bottleneck for breeding programmes, and new tools are required to overcome this problem. This study evaluated the use of a portable structured light scanner and a 3D modelling to recover biometric information of the rump region in cattle. Virtual 3D models were created based on coordinates extracted from the points-cloud obtained through reverse engineering. A MATLAB algorithm was implemented to identify reference points, which were used to automatically calculate rump width, length, and angle. Results were compared to measurements performed directly in vivo and in the 3D models. There was no difference among rump parameter values obtained among biometry methods, though an interaction with body condition score was observed for rump width. The algorithm allowed evaluating correlations within biometric parameters, as well as extracting silhouettes of selected areas to evaluate differences caused by the mobilisation of subcutaneous fat. © 2016 Informa UK Limited, trading as Taylor & Francis Group

Morais H.C.,University of Brasilia | Sujii E.R.,Embrapa Cenargen | Almeida-Neto M.,University of Brasilia | De-Carvalho P.S.,University of Brasilia | And 2 more authors.
Biotropica | Year: 2011

Decrease in the species composition similarity of herbivore assemblages with increasing phylogenetic distance between host plants is a widespread pattern. Here we used data for caterpillars in the Brazilian Cerrado to investigate how the similarity in caterpillar species composition decreases as the taxonomic level and genetic distance (GD) of their host plants increases. In addition, we elucidate the plant taxonomic level that provides the greatest contribution to turnover in the caterpillar species composition among host taxa. Adult Lepidoptera were reared from caterpillars collected from 52 plants over 13yr in the same area, with each host plant sampled for 1yr. Most species were specialists, with 66 percent of genus specialists among the nonsingleton species. The similarity in caterpillar species composition across plant taxa decreased from host species to genera, and from host genera to orders. Above this level, the similarity was consistently low. The GD between plants explained 82 percent of the variation in the similarity of caterpillar species composition. The contribution of caterpillar species turnover among host orders from the same superorder and among host superorders from the same subclass explained 70 percent of the caterpillar species richness as a whole. Our results lend support to the view that most tropical caterpillars are host specialists. Our findings further indicate that the number of orders and superorders of plants provide the greatest contribution to the total caterpillar richness compared with all of the other host taxonomic levels combined. © 2011 The Author(s). Journal compilation © 2011 by The Association for Tropical Biology and Conservation.

Alves M.F.,Federal University of Goais | Barroso P.A.V.,GO Corporation | Ciampi A.Y.,Embrapa Cenargen | Hoffmann L.V.,GO Corporation | And 2 more authors.
Genetics and Molecular Research | Year: 2013

Gossypium mustelinum is the only cotton species native to Brazil; it is endemic to the semi-arid region of the northeast. The populations are found near perennial and semi-perennial sources of water, such as ponds or pools in intermittent streams. Problems with in situ conservation derive from human interference in its habitat, mainly because of excessive cattle grazing and deforestation. Establishing efficient strategies for in situ conservation requires knowledge of the genetic structure of the populations. We evaluated the structure and genetic variability of populations of G. mustelinum in the Tocó and Capivara Rivers (State of Bahia). Two hundred and eighteen mature G. mustelinum plants were genotyped with SSR markers. The molecular data were used to estimate the allelic frequencies, the heterozygosity, the F statistics, and the genetic distance among the populations and among individuals. We found high genetic diversity among the populations. The FST indexes for each population were also high and strongly correlated with physical distance. The high estimated level of endogamy and the low observed heterozygosity are indicative that the populations reproduce mainly by self-fertilization and crosses between related individuals. Consequently, strategies for in situ preservation should include at least three occurrence sites of G. mustelinum from each population. For ex situ conservation, the collections should include as many sites as possible. © FUNPEC-RP.

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