The genetics of symbiotic nitrogen fixation: comparative genomics of 14 Rhizobia Strains by resolution of protein clusters.

The symbiotic relationship between legumes and nitrogen fixing bacteria is critical for agriculture, as it may have profound impacts on lowering costs for farmers, on land sustainability, on soil quality, and on mitigation of greenhouse gas emissions. However, despite the importance of the symbioses to the global nitrogen cycling balance, very few rhizobial genomes have been sequenced so far, although there are some ongoing efforts in sequencing elite strains. In this study, the genomes of fourteen selected strains of the order Rhizobiales, all previously fully sequenced and annotated, were compared to assess differences between the strains and to investigate the feasibility of defining a core ?symbiome??the essential genes required by all rhizobia for nodulation and nitrogen fixation. Comparison of these whole genomes has revealed valuable information, such as several events of lateral gene transfer, particularly in the symbiotic plasmids and genomic islands that have contributed to a better understanding of the evolution of contrasting symbioses. Unique genes were also identified, as well as omissions of symbiotic genes that were expected to be found. Protein comparisons have also allowed the identification of a variety of similarities and differences in several groups of genes, including those involved in nodulation, nitrogen fixation, production of exopolysaccharides, Type I to Type VI secretion systems, among others, and identifying some key genes that could be related to host specificity and/or a better saprophytic ability. However, while several significant differences in the type and number of proteins were observed, the evidence presented suggests no simple core symbiome exists. A more abstract systems biology concept of nitrogen fixing symbiosis may be required. The results have also highlighted that comparative genomics represents a valuable tool for capturing specificities and generalities of each genome.bitstream/item/74069/1/ID-34062.pd

Populational fluctuation and spatial distribution of Alphitobius diaperinus (Panzer) (Coleoptera; Tenebrionidae) in a poultry house, Cascavel, Parana state, Brazil.

Abstract Knowledge of the population fluctuation and spatial distribution of pests is fundamental for establishing an appropriate control method. The population fluctuation and spatial distribution of the Alphitobius diaperinus in a poultry house in Cascavel, in the state of Parana, Brazil, was studied between October, 2001 and October 2002. Larvae and adults of the lesser mealworm were sampled weekly using Arends tube traps (n = 22) for six consecutive flock grow-outs. The temperature of the litter and of the poultry house was measured at the same locations of the tube traps. Beetle numbers increased continuously throughout all the sampling dates (average 5,137 in the first week and 18,494 insects on the sixth week). Significantly greater numbers of larvae were collected than adults (1 to 20 times in 95% of the sampling points). There was no correlation between temperature and the number of larvae and adults collected, therefore no fluctuation was observed during the sampling period. The population growth was correlated to litter re-use. The highest temperatures were observed in deep litter. The spatial distribution of larvae and adults in the poultry house was heterogeneous during the whole period of evaluation. Results suggest that monitoring in poultry houses is necessary prior to adopting and evaluating control measures due to the great variability of the insect distribution in the poultry house. Keywords: lesser mealworm, poultry house, temperature, population dynamicbitstream/item/78871/1/ID-27879.pd

Production, breeding and potential of cowpea crop in Brazil.

About 50 years ago cowpea was reported as a relatively minor tropical legume. However, in the last years, it has been emerging as one of the most important food legume of the 21st century (SINGH, 2010). Brazil is not out of this panorama. Brazilian agriculture is undergoing major technological changes and, in addition, globalization in agribusiness has caused impacts on the production chain of several crops, particularly those heavily dependent on the use of a large volume of agricultural inputs, mainly fertilizers and pesticides. Such crops have had a higher production cost each year. On the other hand, this situation has brought new opportunities. Business farmers have sought new alternatives for their production arrangements. In this context cowpea constitutes one of the best options.bitstream/item/85620/1/Doc-216-Production.pd

Application of bayesian inference in animal breeding using the Intergen program: manual of version 1.2.

Introduction; What?s New in Version 1.2; Parameter file; How to run the program; How to continue an ongoing chain; Output files

Tan spot disease of wheat: race characterization.

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Vermicompostagem.

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Barragem subterrânea: experiências no território do Sertão do Araripe, Estado de Pernambuco.

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Estratégias para o fortalecimento do sistema brasileiro de pesquisa agropecuária.

Organização da pesquisa agropecuária no período pre-Embrapa; A Empresa Brasileira de Pesquisa Agropecuária-EMBRAPA; O modelo institucional de pesquisa; O sistema de programação da pesquisa; Os retornos sociais dos investimentos realizados; Oferta de tecnologias e serviços; Agenda para o futuro; Prioridades da pesquisa agropecuária; Fortalecimento do Sistema Cooperativo de Pesquisa Agropecuária; Articulação inter institucional.bitstream/item/102168/1/Estrategias-para-o-fortalecimento.pd

Conhecendo espécies de plantas da Amazônia: ingá-vermelha [Inga alba (Sw.) Willd. - Leguminosae - Mimosoideae].

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Prós e contra da resistência genética dos ovinos aos helmintos gastrintestinais.

É possível selecionar ovinos mais resistentes às parasitoses dentro do próprio rebanho; Fenótipos; A seleção por OPG permite respostas favoráveis à obtenção de ovinos mais resistentes aos parasitos gastrintestinais; Tipos de desafio; Correlação da seleção por OPG com características produtivas; Programas de seleção; Desafio de campo.bitstream/item/55753/1/DT-79.pdfDisponível no formato online