oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

4 ( 1 )

2019 ( 26 )

2018 ( 46 )

2017 ( 37 )

Custom range...

Search Results: 1 - 10 of 26783 matches for " Renato Mendes;Carvalho "
All listed articles are free for downloading (OA Articles)
Page 1 /26783
Display every page Item
Condicionamento fisiológico em matriz sólida de sementes de café (Coffea arabica L.) com e sem pergaminho
Carvalho, Carlos Alberto Machado;Guimar?es, Renato Mendes;Silva, Tanismare Tatiana de Almeida;
Revista Brasileira de Sementes , 2012, DOI: 10.1590/S0101-31222012000100012
Abstract: the objective of this study was to evaluate the germination and vigor of coffea arabica l. cv. catuaí vermelho iac 99 seeds, with and without parchment, submitted to physiological conditioning in a solid matrix for different time periods. the experimental design was a 2 x 4 factorial, with physiological conditioning of seeds, with and without parchment, and four conditioning times (0, 4, 8 and 12 days). the seeds were maintained at 30 oc in a solid matrix, with an adjustment of 100% of the water-holding capacity. after conditioning, the parchment of all the seeds was manually removed and the moisture, germination and vigor were evaluated. it was found that the presence of parchment did not influence the conditioning effects on seed quality. conditioning for time periods of 4 and 8 days did not improve coffee seed quality, but there was loss in germination and vigor with 12 days conditioning.
Avalia??o da qualidade de sementes de Tabebuia serratifolia Vahl Nich. e T. impetiginosa(Martius ex A. P. de Candolle) Standley - (Bignoniaceae) pelo teste de raios X
Oliveira, Luciana Magda de;Carvalho, Maria Laene Moreira de;Guimar?es, Renato Mendes;Masetto, Tathiana Elisa;
Revista Brasileira de Sementes , 2004, DOI: 10.1590/S0101-31222004000200019
Abstract: to study the efficiency of the x-ray test on the evaluation of internal damage in yellow ipê (tabebuia serratifolia) and purple ipê (t. impetiginosa) seeds and to verify the effect of damage on germination, the seeds were submitted to different times and intensity of radiation exposition. the intensity of 55kv for 25 seconds allowed the best visualization of the internal structures. after that, the seeds of both species were divided into three categories according to their internal anatomy visualized by the radiographs: whole seeds, seeds with damage and empty seeds. the seeds with damage were divided into three sub-categories: seeds with little damage, seeds with severe damage and deformed seeds. the seeds were submitted to the germination test in sand at 30oc under constant light. the x-ray test was efficient in the evaluation of internal damage in yellow ipê and purple ipê seeds. the internal damage observed by radiographs affected germination of ipê seeds decreasing seed lot quality.
Physiological maturity of eggplant seeds Maturidade fisiológica de sementes de berinjela
Denize Carvalho Martins,Fernanda Keila Junqueira Vilela,Renato Mendes Guimar?es,Luiz Ant?nio Augusto Gomes
Revista Brasileira de Sementes , 2012, DOI: 10.1590/s0101-31222012000400002
Abstract: Determination of seed physiological maturity and ideal moment for harvesting fruits to extract their seeds are important aspects to produce seeds with high quality. To identify the best period for harvesting eggplant fruits, associated with ideal resting period of the fruit for extracting seeds, an eggplant production field was installed in municipality of Ijaci, in the State of Minas Gerais, Southwestern Brazil. The fruits were harvested at periods of 49, 56, 63, 70, and 77 days after pollination (DAP). The seeds of fruits harvested in each period were manually extracted immediately after harvest or after a post-harvest resting period of seven days, under a shed. The physiological quality of seeds was assessed by tests of: germination percentage; germination and emergence speed indexes; and electrical conductivity; which were carried out in the Central Seed Laboratory, Federal University of Lavras. Electrophoretic analyses of isoenzymes: catalase (CAT); esterase (EST); superoxide dismutase (SOD); and peroxidase (PO), were also therein performed. Results of germination and vigor of seeds have showed that the best period for harvesting the fruit is around 70 DAP; and that seeds should be extracted immediately after harvest. Electrophoretic analysis of enzymes has showed immaturity for eggplant seeds, harvested after 49 DAP. A determina o da maturidade fisiológica das sementes e do momento ideal de colheita dos frutos para extraí-las s o aspectos importantes para a produ o de sementes com alta qualidade. Para identificar a melhor época de colheita dos frutos de berinjela e o tempo ideal de descanso do fruto para extra o das sementes, foi instalado um campo de produ o, no município de Ijaci, MG. Os frutos foram colhidos aos 49, 56, 63, 70 e 77 dias após a poliniza o (DAP). As sementes dos frutos colhidos, em cada época, foram extraídas manualmente, imediatamente após a colheita, ou ent o após repouso pós-colheita, por sete dias, em galp o. A qualidade das sementes foi avaliada por meio dos testes de: germina o; emergência; índices de velocidade de germina o e emergência; e condutividade elétrica; e também a análise eletroforética das isoenzimas catalase (CAT), esterase (EST), superóxido dismutase (SOD) e peroxidase (PO) foram conduzidas no Laboratório Central de Sementes, Universidade Federal de Lavras. Os resultados de germina o e vigor das sementes revelaram que a melhor época para a colheita dos frutos é de, aproximadamente, 70 DAP; e que as sementes devem ser extraídas imediatamente após a colheita. A análise eletroforética das enzimas evidenci
Suitability of the tetrazolium test methodology for recently harvested and stored coffee seeds Adequa o da metodologia do teste de tetrazólio para sementes de café recém colhidas e armazenadas
Aline da Consola??o Sampaio Clemente,Maria Laene Moreira de Carvalho,Renato Mendes Guimar?es
Ciência e Agrotecnologia , 2012, DOI: 10.1590/s1413-70542012000400005
Abstract: Germination of coffee seeds occurs in a slow and non-uniform manner and the tetrazolium test (TZ) may be a quick alternative for assessment of viability, as long as the preparation and imbibition of the seeds is established. This study was performed in two stages: in the first, recently harvested seeds from three coffee cultivars were submitted to four methodologies for removal of the parchment: manual extraction or use of sodium hypochlorite (NaClO at 5%) and two periods of imbibition of the seeds in water (36 and 48 hours) for removal of the embryos. In the second phase, manual removal and the use of NaClO were compared for elimination of the parchment of stored seeds for monthly performance of the tetrazolium test for six months. Sodium hypochlorite is not efficient in total extraction of the parchment and has a negative effect on the results of the TZ test on low moisture coffee seeds. An imbibition time of 48 hours facilitates extraction of embryos and does not affect test results. The tetrazolium test on coffee seeds with different moisture and deterioration levels must be undertaken with manual removal of the parchments. A germina o de sementes de café ocorre de forma lenta e desuniforme e o teste de tetrazólio (TZ) pode ser uma alternativa rápida para a avalia o da viabilidade, desde que os procedimentos de prepara o e embebi o das sementes estejam estabelecidos. O trabalho foi realizado em duas etapas: na primeira, sementes recém-colhidas de cinco cultivares de cafeeiro foram submetidas a quatro metodologias para remo o do pergaminho: extra o manual ou utiliza o de hipoclorito de sódio (NaClO a 5%) e dois períodos de embebi o das sementes em água (36 e 48 horas) para a retirada dos embri es. Na segunda fase, foi comparada a remo o manual e a utiliza o de NaClO para a elimina o do pergaminho de sementes armazenadas para realiza o mensal do teste de tetrazólio durante seis meses. O hipoclorito de sódio n o é eficiente para a extra o total do pergaminho e afeta negativamente os resultados do teste de TZ em sementes de café com baixa umidade. O tempo de embebi o de 48 horas facilita a extra o dos embri es e n o afeta os resultados do teste. O teste de tetrazólio em sementes de café, com diferentes níveis de umidade e deteriora o, deve ser realizado com a remo o manual dos pergaminhos.
SEED PHYSIOLOGY CLASSIFICATION OF LAURACEAE FOREST SPECIES IN RELATION TO THE STORAGE BEHAVIOUR
Antonio Cláudio Davide,Letícia Renata de Carvalho,Maria Laene Moreira de Carvalho,Renato Mendes Guimar?es
CERNE , 2003,
Abstract: Knowledge on the storability of seeds allows the establishment of suitable conditions forkeeping viability after harvest and elaboration of programs for the conservation of germoplasmabanks in the long term. This study aimed to classify seeds of Cryptocarya aschersoniana, Nectandranitidula, Ocotea odorifera and Persea pyrifolia in relation to the storage behavior based on theirtolerance to desiccation and low temperatures. Viability and moisture content were accessed forfreshly-processed seeds; for seeds desiccated; after 90 days for fresh seeds and stored at 5 °C packedin semi-permeable package and after 90 days for dry seeds stored at 5 °C and -18 °C with the impermeable wrapping. Statistical analysis was performed by comparing the overlaying confidence Classifica o fisiológica de sementes de espécies florestais pertencentes à… 30intervals of the means of germination percentage for each species. The seeds of species studyed wereconsidered recalcitrant because loosed viability after desiccation.
Forma o de professores em Educa o Física: o lugar da prática...
Renato Mendes
Pensar a Prática , 2006, DOI: 19806183/rpp.v3i0.40
Abstract:
Efeitos de tempos e temperaturas de condicionamento sobre a qualidade fisiológica de sementes de cafeeiro (Coffea arabica, L.) sob condi??es ideais e de estresse térmico
Lima, Sílvia Mara Pacheco;Guimar?es, Renato Mendes;Oliveira, Jo?o Almir;Vieira, Maria das Gra?as Guimar?es Carvalho;
Ciência e Agrotecnologia , 2004, DOI: 10.1590/S1413-70542004000300004
Abstract: the goal of this work was the evaluation of the adequate times and temperatures for the physiological contitioning and effects of this techinique in the germination on stress conditions, of stored coffee seeds. the experiment was performed in the seed and molecular techniques laboratories of the ufla's agriculture departament. the seeds used were from the cultivar acaiá cerrado. the seeds were harvested in the coffee seed production fields at ufla and stored at room temperature from august/2000 to january/2001, when they were submitted to physiological conditioning under temperatures of 15, 25 and 35°c for 4, 8 and 12 days of imbibitions in water. the conditioning was dosse in bod chambers in presence of light and the air was pumped using small aquarium pumps and compressors. after each treatment the seeds were imediately submitted to the determination of the water content and evaluated through the germination and germination speed tests under thermal stress (20 and 35°c) and enzymes eletrophoresis. seeds without the imbibing treatment were used as control. it was conclued that the water conditioning at 15 and 25°c was efficient in increasing the germination and vigor of coffee seeds under thermal stress conditions, the conditioning at 35°c was not apropriated, the conditioning for four days was the least efficient treatment in improving the physiological quality of seeds, and the physiological conditioning in water was efficient in recovering the vigor, specially at 25°c for 12 days.
Preparo das sementes de café para avalia??o da viabilidade pelo teste de tetrazólio
Clemente, Aline da Consola??o Sampaio;Carvalho, Maria Laene Moreira de;Guimar?es, Renato Mendes;Zeviani, Walmes Marques;
Revista Brasileira de Sementes , 2011, DOI: 10.1590/S0101-31222011000100004
Abstract: the tetrazolium test (tz) is a rapid alternative for evaluating seed viability and has been adopted for the commercialization of coffee seeds. one of the barriers to using this test is the difficulty of extracting the parchment, which requires time and specialized labor. the use of sodium hypochlorite has been recommended for parchment extraction in coffee seeds but this method has not been tested for the tz. coffee seeds of four lots of two varieties were submitted to four methods in the test: manual extraction or use of sodium hypochlorite (200 ml 5% naclo) to remove the parchment and various periods for soaking seeds in water (36 to 48 hours), to remove the embryos. the results of the viability from the tz were compared with those from the germination of seeds with different moisture contents. the use of 5% naclo with 6 hours of soaking is not effective in removing the parchment and adversely affects the results of the tz in coffee seeds with a moisture content below 25%. the imbibition period of coffee seeds in water for 48 hours in the preparation phase for the tz, facilitates embryo extraction without affecting the test results.
Testes rápidos para avalia??o da qualidade fisiológica de sementes de Citromelo swingle
Carvalho, Jairo Ademir;Von Pinho, édila Villea Resende;Oliveira, Jo?o Almir;Guimar?es, Renato Mendes;Bonome, Lisandro Tomas;
Revista Brasileira de Sementes , 2002, DOI: 10.1590/S0101-31222002000100037
Abstract: the most utilized parameter to evaluate the physiological quality of seeds is the germination test. however, citrus seeds present slow germination and germination test may be extended for up to 60 days. in this way, the need for the development of rapid tests to estimate the viability of seeds appears. the evaluation of the physiological quality of citrus seeds by means of fast tests may be considered as an extremely helpful resource for seed-producing enterprises in the sense of enabling a faster and more efficient quality control. so, the objective of this research work was to adapt rapid test methodologies to determine the viability of citromleo swingle seeds assessed in four storage periods. the tests of tetrazolium, of electric conductivity and of exudate ph (phenolphetaleine) were employed. the test of emergence on tray and germination pattern were utilized for comparing the results obtained in those above-quoted. the rapid tests for evaluating viability proved promising for germination monitoring and seedling emergence from the third month's storage and in the absence of dormant seeds emergence from the third month's storage.
Desempenho de sementes de piment?o revestidas com diferentes materiais
Oliveira, Jo?o Almir;Pereira, Carlos Eduardo;Guimar?es, Renato Mendes;Vieira, Antonio Rodrigues;Silva, Jo?o Bosco Carvalho da;
Revista Brasileira de Sementes , 2003, DOI: 10.1590/S0101-31222003000400006
Abstract: the technique of covering seeds has been used mainly for the species which have small seeds, such as vegetables, forage, forest and ornamental species, because besides increasing the size of the seeds for direct sowing, it is possible to add other elements which are necessary for the good development of the plant in its early stages. in this context the objective of the present study was to covered green-pepper seeds in different types of materials and to evaluate their behavior during storage. seeds treated and not treated with rovrin at the dosage of 200g/100kg were submitted to pre-conditioning for the imbibing of seeds in kno3 in -1,1mpa solution, in an aired system for 5 days. after drying the seeds were covered in a mixture of sand + microcellulose and another of limestone + microcellulose. the covered seeds and those not covered were dried and packed in paper envelopes (permeable pack) and in aluminum envelopes (impermeable pack) and stored at room temperature in the seeds analysis laboratory at ufla. the seed quality was evaluated once every four months, for a period of 20 months, using the following parameters: water content, germination test, accelerated aging, controlled deterioration and emergency in soil + sand. from the results, it was possible to conclude that the covering of seeds slows but does not affect the germination rate of the green pepper seeds before storage, but the covered seeds deteriorate faster than the seeds not covered, when stored in permeable packs. the nature of the materials used did not affect the quality of the green pepper seeds stored in impermeable packs.
Page 1 /26783
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.