Avaliação agronômica de genótipos de guandu no cerrado do Distrito Federal.

O ensaio objetivou avaliar quatorze genótipos de guandu na Embrapa Cerrados, Planaltina-DF, no período de dezembro de 2004 a maio de 2006. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. Adotou-se como testemunha a cultivar Fava Larga. Os cortes foram realizados em março e outubro/2005 e fevereiro e maio/2006. As características avaliadas apresentaram diferenças significativas entre os genótipos (P<0,05). Em média, os genótipos apresentaram valores de 16,7 t/ha, 7,6 t/ha, 5,7 t/ha, 13,3 t/ha e 1,6 kg/ha para produção de matéria seca total, de folhas, de hastes finas, de folhas e hastes finas e de proteína bruta, respectivamente. Os teores de PB variaram de 219 g/kg para o genótipo g123-99 e 192 g/kg para o g3-94. Os resultados indicam como promissores os genótipos g168-99, g29m-94, g3-94 e g123-99. Esses genótipos, nas condições do estudo, apresentaram elevada produção de matéria seca de folhas + hastes finas e maior produção de proteína bruta de folhas

Potencial forrageiro de linhagens puras selecionadas de guandu.

RESUMO: O objetivo deste trabalho foi avaliar o potencial de produção de forragem de linhagens puras selecionadas de guandu. O experimento foi realizado na Embrapa Cerrados, em Planaltina, DF, no período de dezembro de 2004 a maio de 2006. Avaliaram-se a produção de matéria seca (MS) e os teores de proteína bruta (PB) de 13 linhagens de guandu, obtidas pelo programa de melhoramento da Embrapa Pecuária Sudeste, São Carlos, SP, e mais a cultivar Fava Larga, usada como testemunha. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. Os cortes foram realizados em março e outubro de 2005 e fevereiro e maio de 2006. As características avaliadas apresentaram diferenças entre linhagens (P < 0,05). As produções (soma de quatro cortes) de matéria seca total, de folhas variaram entre 14,6 e 18,7 t ha-¹; 4,9 e 9,9 t ha-¹; 4,4 e 6,6 t ha-¹; 11,2 e 15,5 t ha-¹; e 1,1 e 2,0 t ha-¹, respectivamente. Os teores (média de quatro cortes) de PB de folhas variaram entre 219 g kg-¹ para linhagem g123-99 e 192 g kg-¹ para g3-94. As linhagens g168-99, g29m-94 e g3-94 destacaram-se para a maioria das características avaliadas. ABSTRACT: The objective of this experiment was to evaluate the forage potential of selected pigeon-pea purês lines. Evaluation was coducted at the Embrapa Cerrados, Planaltina, DF, during December, 2004 to May, 2006. Thirteen selected lines obtained by the pigeon-pea breeding program of the Embrapa Pecuária Sudeste were evaluated, and cultivar Fava Larga was used as control. The experimental designs was a performed at March/2005 and October/2005 and Febrauary/2006 and May/2006. The parameters showed significant between lines (P < 0,05). The yields (sum four cuts) varied from 14,6 and 18,7 t ha-¹; 4,9 and 9,9 t ha-¹; 4,4 and 6,6 t ha-¹; 11,2 and 15,5 t ha-¹; and 1,1 and 2,0 t ha-¹, respectively, for total dry matter, leaves, stems thin, leaves and stems thin and crude protein. Crude protein (average four cuts) ranged from 216 g kg-¹ to g123-99 and 192 g kg-¹ to g3-94. Pigeon-pea lines g168-99, g29m-94 and g3-94 demonstrated superior performance for most of the traits evaluated.bitstream/CPAC-2009/28933/1/bolpd_192.pd

A functional connection between translation elongation and protein folding at the ribosome exit tunnel in Saccharomyces cerevisiae

Proteostasis needs to be tightly controlled to meet the cellular demand for correctly de novo folded proteins and to avoid protein aggregation. While a coupling between translation rate and co-translational folding, likely involving an interplay between the ribosome and its associated chaperones, clearly appears to exist, the underlying mechanisms and the contribution of ribosomal proteins remain to be explored. The ribosomal protein uL3 contains a long internal loop whose tip region is in close proximity to the ribosomal peptidyl transferase center. Intriguingly, the rpl3[W255C] allele, in which the residue making the closest contact to this catalytic site is mutated, affects diverse aspects of ribosome biogenesis and function. Here, we have uncovered, by performing a synthetic lethal screen with this allele, an unexpected link between translation and the folding of nascent proteins by the ribosome-associated Ssb-RAC chaperone system. Our results reveal that uL3 and Ssb-RAC cooperate to prevent 80S ribosomes from piling up within the 5′ region of mRNAs early on during translation elongation. Together, our study provides compelling in vivo evidence for a functional connection between peptide bond formation at the peptidyl transferase center and chaperone-assisted de novo folding of nascent polypeptides at the solvent-side of the peptide exit tunnel

Caracterização de sementes de pinhão (Araucaria angustifolia) de diferentes procedências, do Estado do Paraná.

This study aimed to perform the characterization of raw pine nuts from Curitiba and Guarapuava, cities of Paraná State. The pine nuts showed peculiar characteristics, being influenced by genetic inheritance and or environmental conditions of different cities. The main differences found between samples were in relation to starch content 45,16 ± 1,38 and 57,26 ± 3,15 (g/100g); average mass of seeds 5,35 ± 0,79 and 7,91 ± 0,57(g); and external hardness of almond 13,87 ± 0,57 and 24,11 ± 3,49, respectively for samples from Curitiba and Guarapuava. The pine nuts show as a good source of starch, with pH near to neutrality and a high activity of water so these factors may compromise your stability. Therefore, the regions of sample collection influence the characteristics of pine nuts

Genome-wide association study for femur-related traits in broilers.

Abstract: Due to the intense selection for heavier and faster growing broilers, metabolic disorders such as skeletal problems became a worldwide concern. Advances in genome-wide association study (GWAS) methodologies increased the possibility of elucidating the genetic architecture controlling bone integrity traits. Therefore, the aim of this study was to perform a GWAS to identify potential genetic markers and candidate genes associated with femur traits in a paternal broiler line developed by Embrapa. To this, three femur bone-related traits were evaluated in 1,433 chickens: dry matter (FDM), ash content (FAC) and breaking strength (FBS). Chickens were genotyped using the 600K Affymetrix® Axiom® HD panel. A total of 16 regions associated to FAC, being a significant SNP in the GGA19 (rs317696422) and 15 suggestive SNPs in the GGA1, GGA2, GGA3, GGA5, GGA8, GGA13, GGA19 and GGA24. For FDM, only one SNP (GGA1) was significantly associated and was located in the DSCAM gene. For the FBS, two suggestive regions (GGA12 and GGA15) were found and no QTLs were described for this trait in these regions. According to the results, new candidate genes and miRNAs related to ossification, such as TPVR2, gga-mir-146a and PCP4 were associated to important femur traits in the broiler line under study. Resumo:Devido à intensa seleção de frangos de corte mais pesados &#8203;&#8203;e de crescimento mais rápido, distúrbios metabólicos, como problemas esqueléticos, tornaram-se uma preocupação mundial. Avanços em metodologias de estudo de associação genômica ampla (GWAS) aumentaram a possibilidade de elucidar a arquitetura genética controlando características de integridade óssea. Portanto, o objetivo deste estudo foi realizar um GWAS para identificar potenciais marcadores genéticos e genes candidatos associados às características do fêmur em uma linhagem de frangos de corte paterna desenvolvida pela Embrapa. Para isso, três características relacionadas ao osso do fêmur foram avaliadas em 1.433 aves: matéria seca (FDM), teor de cinzas (FAC) e resistência à ruptura (FBS). As galinhas foram genotipadas usando o painel 600y Affymetrix® Axiom® HD. Um total de 16 regiões associadas ao FAC, sendo um significativo SNP no GGA19 (rs317696422) e 15 SNPs sugestivos no GGA1, GGA2, GGA3, GGA5, GGA8, GGA13, GGA19 e GGA24. Para FDM, apenas um SNP (GGA1) foi significativamente associado e foi localizado no gene DSCAM. Para o FBS, duas regiões sugestivas (GGA12 e GGA15) foram encontradas e não foram descritos QTLs para essa característica nessas regiões. De acordo com os resultados, novos genes candidatos e miRNAs relacionados à ossificação, como TPVR2, gga-mir-146a e PCP4, foram associados a importantes características do fêmur na linha de frangos em estudo

Biogenic weathering bridges the nutrient gap in pristine ecosystems - a global comparison

In many pristine ecosystems there seems to be negative nutrient budget existent, meaning that export exceeds the input received by aeolian deposition and physico-chemical weathering. Such ecosystems should degrade rather quickly, but are often found surprisingly stable on the long run. Our hypothesis was that this nutrient gap is an artefact caused by not considering the contribution of photoassimilatory-mediated biogenic weathering to the overall nutrient input, which might constitute an additional, energetically directed and demand driven pathway. Here, we firstly evaluated the evolution of mutualistic biogenic weathering along an Antarctic chronosequence and secondly compared the biogenic weathering rates under mycorrhized ecosystems over a global gradient of contrasting states of soil development. We found the ability to perform biogenic weathering increasing along its evolutionary development in photoautotroph-symbiont interaction and furthermore a close relation between fungal biogenic weathering and available potassium across all 16 forested sites in the study, regardless of the dominant mycorrhiza type (AM or EM), climate, and plant-species composition. Our results point towards a general alleviation of nutrient limitation at ecosystem scale via directional, energy driven and on-demand biogenic weathering

An excess of niche differences maximizes ecosystem functioning

Ecologists have long argued that higher functioning in diverse communities arises from the niche differences stabilizing species coexistence and from the fitness differences driving competitive dominance. However, rigorous tests are lacking. We couple field-parameterized models of competition between 10 annual plant species with a biodiversity-functioning experiment under two contrasting environmental conditions, to study how coexistence determinants link to biodiversity effects (selection and complementarity). We find that complementarity effects positively correlate with niche differences and selection effects differences correlate with fitness differences. However, niche differences also contribute to selection effects and fitness differences to complementarity effects. Despite this complexity, communities with an excess of niche differences (where niche differences exceeded those needed for coexistence) produce more biomass and have faster decomposition rates under drought, but do not take up nutrients more rapidly. We provide empirical evidence that the mechanisms determining coexistence correlate with those maximizing ecosystem functioning. It is unclear how biodiversity-ecosystem functioning and species coexistence mechanisms are linked. Here, Godoy and colleagues combine field-parameterised competition models with a BEF experiment to show that mechanisms leading to more stable species coexistence lead to greater productivity, but not necessarily to enhanced functions other than primary production