36 research outputs found

    Early selection efficiency for recommendation of Eucalyptus sp.

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    This paper aims to estimate genetic and phenotypical parameters to assess the viability of early selection in progeny tests of Eucalyptus sp. We analyzed data from experiments conducted in the state of Minas Gerais, Brazil. The evaluated traits were diameter at breast height and plant height in 482 progenies of full sibs under randomized block design, into nine experiments: four of which were assessed at progenies mean level, and five assessed at individuals mean level. It were evaluated the predicted gains with combined selection index under 5, 10 and 20% of selection; the coincidence among selected families in juvenile and adult ages, and the efficiency of early selection. Results indicated that the procedures were efficient in most of the scenarios, and the gains comparable to the direct selection on tree harvest age

    Plant stand failures effect in genetic parameters estimation procedure in Eucalyptus sp.

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    The objective of this work was to verify the influence of the percentage of failures in a forest genetics experiment in the estimation of genetic parameters. The study consisted in the evaluation of two experiments of full‑sib families under randomized complete block design with three replicates conducted in the state of Minas Gerais, Brazil. The experiment I was evaluated in January 2002, with approximately 60 months of age. The experiment II was evaluated in January 2003, with 45 months of age. In both experiments, the evaluations consisted of the measurement of the diameter at breast height and plant height. For all the investigated genetic parameters, an increase in the amplitude of the estimates was verified due to the increase in the number of experimental failures. Variances and negative heritabilities were detected, from 35% of failure, indicating that in such cases, this proportion of failure may be problematic to estimate genetic values, to estimate the gain with the selective process and for make decision

    SOIL WATERLOGGING ASSOCIATED WITH IRON EXCESS POTENTIATES PHYSIOLOGICAL DAMAGE TO SOYBEAN LEAVES

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    Many plants are exposed to soil waterlogging, including soybean plants. Soil waterlogging exponentially increases the availability of iron (Fe) and causes O2 depletion, which may result in excessive uptake of Fe and shortage of O2 to the roots and also nodules in leguminous plants, resulting in overproduction of reactive oxygen species and lipid peroxidation. The present study aimed to evaluate physiological damage to soybean leaves at the second trifoliate (V2) stage when exposed to non-waterlogged and waterlogged soils and combined with one moderate and two toxic levels of Fe. Soybean plants were vulnerable to soil waterlogging at all Fe levels tested, presenting the highest values of malonaldehyde, hydrogen peroxide, and Fe accumulation in the shoot, which resulted in accentuated damage to gas exchange and chlorophyll content, consequently leading to lower shoot dry weight. In contrast, soybean plants cultivated under optimal water availability showed less damage caused by excess Fe, mainly at 125 mg dm-3 Fe, since the traits of net photosynthetic rate, water use efficiency, instantaneous carboxylation efficiency, malonaldehyde, and shoot dry weight were not affected. Keywords: chlorophylls; gas exchange; Glycine max; ferrous ion.   Encharcamento do solo associado ao excesso de ferro potencializa os danos fisiológicos às folhas de soja   RESUMO: Muitas plantas estão expostas ao encharcamento do solo, incluindo plantas de soja. O encharcamento do solo aumenta exponencialmente a disponibilidade de ferro (Fe) no solo e causa depleção de O2, o que pode resultar na absorção excessiva de Fe e escassez de O2 para as raízes e também nódulos em plantas leguminosas, resultando em superprodução de espécies reativas de oxigênio e peroxidação lipídica. O presente estudo teve como objetivo avaliar os danos fisiológicos às folhas de soja no segundo estádio trifoliado (V2) quando exposta a solos não encharcados e encharcados combinado com um nível moderado e dois níveis tóxicos de Fe. As plantas de soja foram vulneráveis ​​ao encharcamento do solo em todos os níveis de Fe testados, apresentando os maiores valores de malonaldeído, peróxido de hidrogênio e acúmulo de Fe na parte aérea, o que resultou em danos acentuados nas trocas gasosas e no conteúdo de clorofila, consequentemente levando a menor peso seco de parte aérea. Em contrapartida, plantas de soja cultivadas sob disponibilidade hídrica ótima apresentaram menos danos causados ​​pelo excesso de Fe, principalmente a 125 mg dm-3 Fe, uma vez que as características de taxa fotossintética líquida, eficiência do uso da água, eficiência de carboxilação instantânea, malonaldeído e peso seca da parte aérea não foram afetados. Palavras-chave: clorofilas; trocas gasosas; Glycine max; íon ferroso.Many plants are exposed to soil waterlogging, including soybean plants. Soil waterlogging exponentially increases the availability of iron (Fe) and causes O2 depletion, which may result in excessive uptake of Fe and shortage of O2 to the roots and also nodules in leguminous plants, resulting in overproduction of reactive oxygen species and lipid peroxidation. The present study aimed to evaluate physiological damage to soybean leaves at the second trifoliate (V2) stage when exposed to non-waterlogged and waterlogged soils and combined with one moderate and two toxic levels of Fe. Soybean plants were vulnerable to soil waterlogging at all Fe levels tested, presenting the highest values of malonaldehyde, hydrogen peroxide, and Fe accumulation in the shoot, which resulted in accentuated damage to gas exchange and chlorophyll content, consequently leading to lower shoot dry weight. In contrast, soybean plants cultivated under optimal water availability showed less damage caused by excess Fe, mainly at 125 mg dm-3 Fe, since the traits of net photosynthetic rate, water use efficiency, instantaneous carboxylation efficiency, malonaldehyde, and shoot dry weight were not affected. Keywords: chlorophylls; gas exchange; Glycine max; ferrous ion.   Encharcamento do solo associado ao excesso de ferro potencializa os danos fisiológicos às folhas de soja   RESUMO: Muitas plantas estão expostas ao encharcamento do solo, incluindo plantas de soja. O encharcamento do solo aumenta exponencialmente a disponibilidade de ferro (Fe) no solo e causa depleção de O2, o que pode resultar na absorção excessiva de Fe e escassez de O2 para as raízes e também nódulos em plantas leguminosas, resultando em superprodução de espécies reativas de oxigênio e peroxidação lipídica. O presente estudo teve como objetivo avaliar os danos fisiológicos às folhas de soja no segundo estádio trifoliado (V2) quando exposta a solos não encharcados e encharcados combinado com um nível moderado e dois níveis tóxicos de Fe. As plantas de soja foram vulneráveis ​​ao encharcamento do solo em todos os níveis de Fe testados, apresentando os maiores valores de malonaldeído, peróxido de hidrogênio e acúmulo de Fe na parte aérea, o que resultou em danos acentuados nas trocas gasosas e no conteúdo de clorofila, consequentemente levando a menor peso seco de parte aérea. Em contrapartida, plantas de soja cultivadas sob disponibilidade hídrica ótima apresentaram menos danos causados ​​pelo excesso de Fe, principalmente a 125 mg dm-3 Fe, uma vez que as características de taxa fotossintética líquida, eficiência do uso da água, eficiência de carboxilação instantânea, malonaldeído e peso seca da parte aérea não foram afetados. Palavras-chave: clorofilas; trocas gasosas; Glycine max; íon ferroso

    OTIMIZAÇÃO DA ATIVIDADE DE HERBICIDAS COM DIFERENTES ADJUVANTES NA FITOTOXICIDADE DE Digitaria insularis NO ESTÁDIO DE FLORESCIMENTO

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    The aim of this paper was quantify the effect of the herbicides clethodim and paraquat associated with different adjuvants class on phytotoxicity of Digitaria insularis at flowering stage. The herbicides were applied at 0, 6.25, 12.5, 25, 50, 75 and 100% of recommended label isolated or associated with the adjuvants: nonylphenoxy polyethoxy ethanol at 0.05%; silicone polyether copolymer at 0.1%; lecithin-based adjuvant and acid propionic at 0.5%  and mineral oil at 0.5%. The experimental design were completely randomized with five replications in factorial scheme (herbicides rates x adjuvants). The phytotoxicity effect was visually assessed for paraquat at 12 days after treatment (DAT) and at 21 DAT for clethodim. The treatments applied clethodim with the adjuvants nonylphenoxy polyethoxy ethanol, lecithin-based adjuvant and acid propionic and mineral oil significantly increased the phytotoxicity of D. insularis plants. For the paraquat the increase phytotoxicity of D. insularis plants was provided by the treatment with the lecithin-based and acid propionic adjuvant.O presente trabalho teve como objetivo quantificar o efeito proporcionado pela interação entre os herbicidas clethodim e paraquat associados com diferentes classes de adjuvantes na fitotoxicidade de Digitaria insularis no estádio de florescimento. Os herbicidas foram aplicados nas doses de 0; 6,25; 12,5; 25; 50; 75 e 100% da recomendada pelo fabricante, de forma isolada e em mistura com os adjuvantes: nonil fenoxi poli (etilenoxi) etanol (0,05%); copolímero de poliéter e silicone (0,1%); lecitina e ácido propiônico (0,5%) e óleo mineral (0,5%) no delineamento inteiramente casualizado com cinco repetições em esquema fatorial (doses dos herbicidas x adjuvantes). O efeito fitotóxico foi visualmente avaliado aos 12 dias após aplicação (DAA) para o herbicida paraquat e aos 21 DAA para o herbicida clethodim. Verificou-se em plantas de D. insularis fitotoxidade potencializada para o herbicida clethodim nos tratamentos com os adjuvantes nonil fenoxi poli (etilenoxi) etanol, lecitina e ácido propiônico e óleo mineral. Para o herbicida paraquat, a potencialização da fitotoxicidade nas plantas de D. insularis foi proporcionada somente pelo tratamento com o adjuvante lecitina e ácido propiônico

    Rendimento de grãos de milho segunda safra sob dois regimes hídricos e diferentes sistemas de cultivo

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    O grão do milho está entre os cereais os mais produzidos no Brasil. O consórcio entre as culturas de milho e forrageiras do gênero Urochloa visam a produção de grãos e forragem com boa qualidade nutricional para a produção de pastagem ou formação de palha para sistemas de plantio direto (SPD). Este trabalho objetivou avaliar o rendimento de grãos de milho segunda safra sob diferentes sistemas de cultivo do solo em sistema irrigado e não irrigado, no extremo Oeste do Estado de São Paulo. Foi utilizado o delineamento inteiramente casualizado em esquema de parcela subdividida com sete repetições. Os tratamentos foram compostos por combinações de sistemas de cultivo, nas parcelas, com quatro níveis (sistema convencional de preparo de solo; SPD utilizando Urochloa brizantha cv Paiaguás; U. brizantha cv Piatã; e U. ruziziensis cv Ruziziensis), e lâminas de irrigação nas subparcelas, com dois regimes hídricos (não irrigado e irrigado). Independente dos sistemas de cultivo avaliado, o uso da irrigação proporcionou incremento médio de 1045% de rendimento de grãos de milho em relação ao tratamento não irrigado. Além disso, foi verificado maiores estande final e massa seca de palha residual total, proporcionando, assim, maior aporte de palha e benefícios ao SPD para as safras seguintes. Dentre as coberturas vegetais empregadas no SPD consorciada com o milho, as coberturas Paiaguás e Piatã revelaram ser as melhores opções para o consórcio, sob as condições em que foi realizado o experimento, na região do extremo Oeste do Estado de São Paulo

    Attenuation of motor deficits by hydroethanolic extract of Poincianella pyramidalis in a Parkinson's disease model

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    The present study aimed to evaluate the possible neuroprotective effect of the hydroethanolic extract of Poincianella pyramidalis (EFIPp) (Tul.) L. P. Queiroz (Fabaceae), an endemic plant found in Northeastern Brazil, commonly used in folk medicine, on the motor deficits induced by repeated treatment with reserpine (RES) in rats. Adult male Wistar rats received 10 s.c. injections of 0.1 mg/kg RES or vehicle (VR), every 48 h, and daily i.p. injections daily of HEPp (25 mg/kg) or vehicle (VE). Throughout treatment, catalepsy behavior and oral movements were scored. After behavioral tests, superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in the prefrontal cortex, hippocampus and striatum. RES treatment induced a progressive increase of catalepsy time in the treated group compared to control groups starting at day 15. RES also increased the number of vacuous chewing movements, tongue protrusions and duration of facial twitching. Treatment with HEPp attenuated the motor deficit in the catalepsy test and delayed the onset of oral movements induced by RES. No significant changes were observed in the antioxidant assay. Taken together, these results show a beneficial effect of HEPp on motor deficits induced by reserpine, suggesting a neuroprotective effect in a rat model of PD.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundação de Apoio a Pesquisa e a Inovação Tecnologica do Estado de Sergipe (FAPITEC)Pro-reitoria de Pesquisa da Universidade Federal de Sergipe (POSGRAP/UFS)Univ Fed Sergipe, Dept Physiol, Sao Cristovao, SE, BrazilUniv Massachusetts, Neurosci & Behav Program, Amherst, MA 01003 USAMinist Educ, CAPES Fdn, BR-70040020 Brasilia, DF, BrazilUniv Fed Sao Paulo, Dept Biosci, Santos, SP, BrazilUniv Fed Sao Paulo, Dept Pharmacol, Sao Paulo, SP, BrazilUniv Fed Sergipe, Dept Biosci, Itabaiana, SE, BrazilUniv Fed Sao Paulo, Dept Biosci, Santos, SP, BrazilUniv Fed Sao Paulo, Dept Pharmacol, Sao Paulo, SP, BrazilWeb of Scienc

    Attenuation of motor deficits by hydroethanolic extract of Poincianella pyramidalis in a Parkinson’s disease model

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    The present study aimed to evaluate the possible neuroprotective effect of the hydroethanolic extract of Poincianella pyramidalis (EHPp) (Tul.) L. P. Queiroz (Fabaceae), an endemic plant found in Northeastern Brazil, commonly used in folk medicine, on the motor deficits induced by repeated treatment with reserpine (RES) in rats. Adult male Wistar rats received 10 s.c. injections of 0.1 mg/kg RES or vehicle (VR), every 48 h, and daily i.p. injections daily of HEPp (25 mg/kg) or vehicle (VE). Throughout treatment, catalepsy behavior and oral movements were scored. After behavioral tests, superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in the prefrontal cortex, hippocampus and striatum. RES treatment induced a progressive increase of catalepsy time in the treated group compared to control groups starting at day 15. RES also increased the number of vacuous chewing movements, tongue protrusions and duration of facial twitching. Treatment with HEPp attenuated the motor deficit in the catalepsy test and delayed the onset of oral movements induced by RES. No significant changes were observed in the antioxidant assay. Taken together, these results show a beneficial effect of HEPp on motor deficits induced by reserpine, suggesting a neuroprotective effect in a rat model of PD
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