Estudos genético-genômicos em Urochloa decumbens

Author(s):  
Rebecca Caroline Ulbricht Ferreira
Keyword(s):  
2019 ◽  
Vol 17 ◽  
pp. 95-102
Author(s):  
Dandara R. Muniz ◽  
Janaina S. Garcia ◽  
Taniris C. Braga ◽  
Ângelo de Fátima ◽  
Luzia V. Modolo

2019 ◽  
Vol 13 ((03) 2019) ◽  
pp. 380-385 ◽  
Author(s):  
Soraya Marx Bamberg ◽  
Silvio Junio Ramos ◽  
Marco Aurelio Carbone Carneiro ◽  
José Oswaldo Siqueira

Fertilizer application can enhance the nutritional value of plants, such effects being influenced by the presence of arbuscular mycorrhizal fungi (AMF). Nutrients × AMF interactions are well-known for variety of elements but very little has been addressed on biofortification of selenium (Se) in plants grown in tropical soils. The purpose of this study was to evaluate the effect of Se application and AMF inoculation on growth and micronutrient contents on soybean plants as forage grass. The experiments were conducted in a completely randomized factorial design with five Se doses (0.0, 0.5, 1.0, 2.0 and 3.0 mg kg-1 for soybean plants, and 0.0, 0.5, 1.0, 3.0 and 6.0 mg kg-1 for forage plants), with and without AMF inoculation in three replicates. The results showed that soil Se had only slight effect on soybean growth but it caused a two-fold increase on grain yield. However, the growth of forage grass was enhanced by Se application when AMF was present. The AMF inoculation reduced benefit for soybean growth and yield but marked positive effect on forage grass at high doses of Se. Selenium contents in both plants were increased by its application in soil, being such effect proportional to soil applied doses. Selenium application and AMF inoculation had marked effects on micronutrients contents in both soybean plants and forage grass and they may contribute to Se and micronutrient biofortification.


2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Rebecca C. U. Ferreira ◽  
Letícia J. Cançado ◽  
Cacilda B. do Valle ◽  
Lucimara Chiari ◽  
Anete P. de Souza

Author(s):  
P. F. Cannon

Abstract A description is provided for Puccinia levis var. brachiariae comb. nov., which causes small lesions on young stems and leaf lamina of the host plant and, where present in quantity, could significantly reduce vigour. Some information on its dispersal and transmission and conservation status is given, along with details of its geographical distribution (Malawi, Uganda, Zambia and Brazil) and hosts (Brachiaria brizantha [Urochloa brizantha], B. decumbens [Urochloa decumbens], B. humidicola [Urochloa humidicola] and an unnamed Brachiaria sp.).


2016 ◽  
Vol 38 (3) ◽  
pp. 363 ◽  
Author(s):  
Frank Akiyoshi Kuwahara ◽  
Gustavo Maia Souza ◽  
Kezia Aparecida Guidorizi ◽  
Ciniro Costa ◽  
Paulo Roberto de Lima Meirelles

Water deficiency during the dry seasons influences the relationship between water and gas exchange in tropical grasses, reducing their productive potential. In addition, the phosphorus (P) deficiency Brazilian soils adds to the set of factors limiting crop production. In this context, the objective of this study was to evaluate the responses of different tropical forage species to phosphorus supplementation as mitigating the damage caused by water stress. Seeds of Urochloa brizantha cv. MG-4, Urochloa decumbens cv. Basilisk, Panicum maximum cv. Áries, Panicum maximum cv. Tanzânia and Paspalum atratum cv. Pojuca were germinated in pots containing 10 liters of red-yellow Acrisol type soil. Experiments were conducted by combining levels of phosphorus, 8,0 and 100,0 mg of P dm-3, with two irrigation regimes, 100 and 40% replacement of transpired water. The biometric parameters, photosynthetic capacity, leaf water potential and soil chemical characteristics were evaluated, and the data was submitted to analysis of variance (ANOVA, p < 0.05), and subsequently the means were compared using a Tukey test (p < 0.05). The results showed for tropical grasses grown under water stress, there is a clear mitigating effect of phosphorus supplementation, especially on the maintenance of biomass growth. 


2016 ◽  
Vol 3 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Gabriel Felipe Vogel ◽  
Rubens Fey
Keyword(s):  

O objetivo deste trabalho foi avaliar a resistência do solo à penetração sob quatro diferentes sistemas de manejo do solo (café; amoreira; pastagem; silvipastoril) em três profundidades (0,0-0,20 m; 0,20-0,40 m; 0,40-0,60 m). O presente estudo foi realizado em Jardim Alegre–PR, em um Latossolo Vermelho. Os manejos foram: 1 - Cafezal cultivado manualmente; 2 - Área com amoreira para produção de bicho-da-seda, com tráfego de máquinas; 3 - Pastagem de braquiária (Urochloa decumbens) em sistema rotacionado, com taxa de lotação variada; 4 - Sistema silvipastoril com U. decumbens e eucalipto, com taxa de lotação variada. Houve interação significativa entre os diferentes tipos de manejo do solo e as profundidades. Na profundidade de 0,0-0,20 m as menores compactações foram encontradas nos sistemas silvipastoril e cafezal devido ao manejo sem tráfego de máquinas, contrariamente a área de amoreira. A pastagem apresentou a maior RMP devido ao pisoteio animal e ao não revolvimento anterior à implantação, diferentemente dos demais. Na camada de 0,20-0,40 m a área de pastagem apresentou os menores resultados de RMP, ao contrário das áreas que sofreram preparo do solo na sua implantação, ou seja, foi verificado expressivo efeito de “pé-de-grade” nas áreas onde houve revolvimento antes da implantação. Nos 0,40-0,60 m houve maior compactação no sistema silvipastoril em relação aos demais devido principalmente à compactação ocasionada pelo crescimento radicular mais pronunciado nesta profundidade.


2017 ◽  
Vol 16 (3) ◽  
pp. 198 ◽  
Author(s):  
Lívia Felicio Barreto ◽  
Ricardo Augusto Decaro ◽  
Marina Gomes da Silva ◽  
Fabiano Griesang ◽  
Marcelo Da Costa Ferreira
Keyword(s):  

O uso de herbicidas é uma prática muito utilizada para o controle de plantas daninhas. Entretanto, sua eficácia pode ser comprometida pela menor disponibilidade de água no ambiente, influenciando na absorção, translocação e metabolismo destes pelas plantas. O presente trabalho objetivou estudar o efeito dos herbicidas paraquat (Gramoxone) e glyphosate (Roundup Original) para o controle de capim-braquiária [Urochloa decumbens (Stapf) R.D.Webster (Poaceae)] e corda-de-viola [Merremia cissoides (Lam.) Hallier f. (Convolvulaceae)], em condições de déficit hídrico. O experimento foi conduzido em casa de vegetação, em delineamento experimental inteiramente casualizado e esquema fatorial 5×3, com três repetições. Foram consideradas cinco épocas de indução de déficit hídrico (0, 1, 3, 5 e 7 dias) e três caldas de pulverização [paraquat, glyphosate e testemunha (com a aplicação de água, apenas)]. As avaliações de porcentagem de controle foram realizadas aos 2, 5, 7, 10, 14 e 21 dias após a aplicação dos tratamentos. Aos 21 dias foi determinado o teor de massa seca das plantas daninhas. Pelos resultados obtidos, observou-se que a partir de 5 dias com déficit hídrico, a eficácia dos herbicidas paraquat e glyphosate para o controle de capim-braquiária e corda-de-viola foi reduzida.


Author(s):  
Eduardo Pradi Vendruscolo ◽  
Aliny Heloísa Alcântara Rodrigues ◽  
Sávio Rosa Correia ◽  
Paulo Ricardo de Oliveira ◽  
Luiz Fernandes Cardoso Campos ◽  
...  
Keyword(s):  

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
Y. GRAAT ◽  
A.L. BACHA ◽  
M.P. NEPOMUCENO ◽  
P.L.C.A. ALVES

ABSTRACT: This study aimed at evaluating the effects of different desiccation periods of Urochloa decumbens on the initial development of Eucalyptus urograndis (clone C-219H). The experiment was conducted in 100 liter concrete boxes, previously filled with Dark-Red Latosol. U. decumbens was sown in all plots, except for the control sample without covering. After 95 days from sowing, the herbicide glyphosate (dose of 1,424 g a.e. ha-1) was sprayed at intervals of 0 (Apply-Plant), 7, 14, 21, 28 and 35 days before eucalyptus planting, plus a control sample without covering, totaling seven treatments. A completely randomized design with six replications was used. Eucalyptus plants were evaluated 30, 60 and 90 days after planting (DAP), when the height of the plants and the diameter of the stem were determined. At the end of the experimental period (90 DAP), the leaf area and the dry matter of leaves and stem were measured. It is possible to conclude that the Apply-Plant modality was harmful to some of the eucalyptus characteristics (E. urograndis - C-219H), while planting the seedlings in periods over 14 days after the desiccation of U. decumbens plants promoted a better development of the culture.


2019 ◽  
Vol 40 (6Supl3) ◽  
pp. 3719
Author(s):  
Victor Rezende Moreira Couto ◽  
Mário Fonseca Paulino ◽  
Sebastião de Campos Valadares Filho ◽  
Edenio Detmann ◽  
Marlos Oliveira Porto ◽  
...  

This study was undertaken to examine production performance, pasture and milk intakes and nutrient digestibility in heifers supplemented with different levels of energy in a creep-feeding system on Urochloa decumbens Stapf pastures during the rainy-dry transition season. Fifty-one heifers with predominant Nellore genetic composition (average initial age and weight: 120 days and 133.4 ± 3.12 kg) and their respective dams were used in an evaluation of production performance, intake, and diet digestibility. Four treatments were evaluated, namely, MM - mineral mixture; T250 - 0.250 kg of supplement per head per day; T500 - 0.500 kg of supplement per head per day; and T750 - 0.750 kg of supplement per head per day, totaling three groups with 13 animals each and one group with 12 animals. All supplements were balanced to provide 100 g of CP animal-1 day-1. LIPE® and chromium oxide were used as external markers to estimate fecal excretion and individual DM and supplement intakes, respectively, whereas iNDF was used as an internal marker for pasture DM intake. Production performance did not differ between the supplemented and unsupplemented animals. Total DM intake and pasture DM intake were higher in the group supplemented with concentrate, and the same was observed for the digestibility of DM and NDFap consumed by the animals. The average cow milk yield was 5.33 kg/day, with average protein and fat contents of 3.51% and 4.85%, respectively. In conclusion, compared to the use of mineral mixture only, multiple supplementation at different levels containing 100 g of CP does not significantly improve performance in lactating beef heifers grazing on Urochloa decumbens Stapf and supplemented during the rainy-dry transition season.


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