Avaliação da perda da tolerância à dessecação e da quantidade de dna nuclear em sementes de Peltophorum dubium (spreng.) taubert durante e após a germinação

Guimarães, Cristiane Carvalho; Faria, José Márcio Rocha; Oliveira, Julio Maia de; Silva, Edvaldo Aparecido Amaral da

doi:10.1590/s0101-31222011000200002

Cited by 15 publications

(12 citation statements)

References 19 publications

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“…Masetto, Faria, and Fraiz (2015) observed that germinated seeds of Sesbania virgata with a 1 mm radicle still maintained their desiccation tolerance and that total loss of this capacity only occurred when the radicles reached 2 mm. Similar results of DT loss after radicle protrusion were found by Guimarães, Faria, Oliveira, and Silva, (2011) in Peltophorum dubium.…”

Section: Resultssupporting

confidence: 86%

Physiological and biochemical changes during desiccation tolerance loss in millet (<i>Pennisetum glaucum</i> L.) seeds

et al. 2019

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The aim of this study was to evaluate the physiological and biochemical changes related to the loss of desiccation tolerance in millet seeds. The points studied were determined according to the seed imbibition curve of the hybrid ADRF6010: control (0 h), 3 h, 1 and 3 mm of radicle. The seeds were dried on silica gel for 72 h at 20 °C, followed by pre-humidification at 25 °C for 24 h. The physiological quality was evaluated by the electrical conductivity and germination test, and the seed vigor through the first count and germination speed index. The experiment was performed in a completely randomized design and means were compared by the Scott-knott test at 5% probability. The enzymatic systems evaluated were: superoxide dismutase, catalase, peroxidase, and α-amylase, and the expression of heat-resistant proteins. The enzymatic activity was quantified through the software ImageJ®. Millet seeds lost desiccation tolerance when the radicle reaches 1 mm of length. According to the enzymatic standards, the enzymes peroxidase and α-amylase, as well as the activity of heat-resistant proteins are related to the loss of desiccation tolerance in millet seeds.

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Section: Resultssupporting

confidence: 86%

Physiological and biochemical changes during desiccation tolerance loss in millet (<i>Pennisetum glaucum</i> L.) seeds

et al. 2019

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“…Masetto (2008) observed that Sesbania virgata germinated seeds with a 1 mm radicle still retained desiccation tolerance and the total loss of this capacity took place when radicles reached 2 mm. The loss of desiccation tolerance only after radicle protrusion was also observed in Peltophorum dubium (Guimarães et al, 2011), Solanum lycopersicum and Abelmoschus esculentus (Lin et al, 1998). Oliveira (2009) observed that scarified seeds of Leucaena leucocephala lost desiccation tolerance only after radicle protrusion, differently to this study.…”

Section: Discussioncontrasting

confidence: 44%

“…Guimarães et al (2011) verified that the drying of in Peltophorum dubium germinated seeds causes complete disorganisation of the cell structure, with organelle membrane degradation and plasma membrane damage. Damage to the cell structure has also been reported in other species such as recalcitrant embryonic axes of Trichilia emetica (Kioko et al, 2006) and orthodox seeds of Leucaena leucocephala (Oliveira, 2009).…”

Section: Discussionmentioning

confidence: 82%

Loss of desiccation tolerance in Copaifera langsdorffii Desf. seeds during germination

et al. 2014

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This study evaluated the loss of desiccation tolerance in C. langsdorffii seeds during the germination process. Seeds were imbibed for 24, 48, 72, 96, 120 and 144 hours and dried to the initial moisture content, kept in this state for 3 days after which they were submitted to pre-humidification and rehydration. Ultraestructural evaluations were done aiming to observe the cell damage caused by the dry process. Desiccation tolerance was evaluated in terms of the percentage of normal seedlings. Seeds not submitted to the drying process presented 61% of normal seedlings, and after 24 hours of imbibition, followed by drying, the seeds presented the same percentage of survival. However, after 48 hours of imbibition, seeds started to lose the desiccation tolerance. There was twenty six percent of normal seedlings formed from seeds imbibed for 96 hours and later dried and rehydrated. Only 5% of seeds imbibed for 144 hours, dried and rehydrated formed normal seedlings. At 144 hours of imbibition followed the dry process, there was damage into the cell structure, indicating that the seeds were unable to keep the cell structure during the drying process. Copaifera langsdorffii seeds loses the desiccation tolerance at the start of Phase 2 of imbibition.Keywords: Copaíba, desiccation sensitivity, imbibition. Perda da tolerância à dessecação em sementes deCopaifera langsdorffii durante a germinação ResumoEste estudo avaliou a perda da tolerância à dessecação em sementes de C. langsdorffii durante o processo germinativo. Sementes foram embebidas por 24, 48, 72, 96, 120 e 144 horas e depois secas até a umidade inicial, sendo mantidas neste estado durante 3 dias, quando então foram submetidas a pré-umidificação e reidratação. Avaliações ultraestruturais foram realizadas objetivando observar danos nas células causados pelo processo de secagem. A tolerância à dessecação foi avaliada pelo percentual de plântulas normais. Sementes não submetidas ao processo de secagem apresentaram 61% de plântulas normais, sendo que após 24 horas de embebição seguida de secagem, houve o mesmo percentual de sobrevivência. Contudo, após 48 horas de embebição, as sementes começaram a perder a tolerância à dessecação. Vinte e seis por cento de sementes formaram plântulas normais após embeberem por 96 horas e secas. Apenas 5% de sementes embebidas por 144 horas e secas formaram plântulas normais. Após 144 horas de embebição, seguida de secagem, verificou-se danos na estrutura celular, o que indica que as sementes não são capazes de manter a estrutura celular durante o processo de secagem. Verificou-se no presente estudo que sementes de C. langsdorffii perdem a tolerância à dessecação no inicio da fase 2 da embebição.Palavras-chave: Copaíba, sensibilidade à dessecação, embebição.

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“…Moreover, soil moisture can accelerate and standardize the seed germination process. Podocarpus lambertii has orthodox seeds, which remain viable after dehydration (Garcia and Nogueira 2008); however, orthodox seeds lose tolerance to desiccation in the early stages, but when rehydrated, they maintain their physiological functions influencing the germination process (Guimarães et al 2011). In addition to altering soil moisture and structure, forest patches normally enhance soil nutrients (C, N, P, and cations; Scholes and Archer 1997).…”

Section: Importance Of Forest Patches To P Lambertiimentioning

confidence: 99%

Population dynamics of Podocarpus lambertii in southern Brazilian forest–grassland mosaics

et al. 2019

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The grasslands conversion to forests is occurring globally and modifying the population dynamics of species. Here, we characterized the population dynamics of Podocarpus lambertii Klotzsch ex Endl. over four years in southern Brazilian forest–grassland mosaics. We asked (i) if the studied P. lambertii population would decrease or increase over time and (ii) what the role of forest patches is in the growth and recruitment of a P. lambertii population. Thus, we studied forest–grassland mosaics, stratified the population into four demographic classes, evaluated the population dynamics, and estimated the correlation between canopy cover and average number of individuals. All individuals of P. Lambertii occurred in forest patches. Density was high but decreased from seedlings to the reproductive stage. The population growth rate was λ = 1.025, and the recruitment of individuals was high and variable among years. The transition and mortality rates showed a pattern of reduction from seedlings to the reproductive stage. Mortality rate for seedlings and juveniles was low and concentrated at the smaller heights. The correlations between canopy cover and the average number of individuals were positive and significant. The ecological characteristics of this species and specific conditions provided by forest patches allow population growth and species conservation in the southern Brazilian forest–grassland mosaics.

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Avaliação da perda da tolerância à dessecação e da quantidade de dna nuclear em sementes de Peltophorum dubium (spreng.) taubert durante e após a germinação

Cited by 15 publications

References 19 publications

Physiological and biochemical changes during desiccation tolerance loss in millet (<i>Pennisetum glaucum</i> L.) seeds

Physiological and biochemical changes during desiccation tolerance loss in millet (<i>Pennisetum glaucum</i> L.) seeds

Loss of desiccation tolerance in Copaifera langsdorffii Desf. seeds during germination

Population dynamics of Podocarpus lambertii in southern Brazilian forest–grassland mosaics

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