Preparo das sementes de café para avaliação da viabilidade pelo teste de tetrazólio

Clemente, Aline da Consolação Sampaio; Carvalho, María Laene Moreira de; Guimarães, Renato Mendes; Zeviani, Walmes Marques

doi:10.1590/s0101-31222011000100004

Cited by 19 publications

(16 citation statements)

References 4 publications

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“…In the tetrazolium test, four replications of 10 seeds were used, which were soaked in distilled water for 48 hours at 30°C (Clemente et al, 2011). After soaking, the embryos were removed with a scalpel to prevent damage to them.…”

Section: Methodsmentioning

confidence: 99%

Cryopreservation of coffee seeds: a simplified method

Coelho

Rosa

Fernandes

2017

Seed Science and Technology

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Coffee seeds are sensitive to desiccation and to storage. Advances in the technique of cryopreservation of these seeds have been achieved in recent years, and the aim of this study was to evaluate Coffea arabica seeds cryopreserved through direct immersion in liquid nitrogen after rapid and slow drying. Seeds of the cultivars 'Arara', 'Catiguá', 'Catuaí Amarelo' and 'Mundo Novo' underwent rapid and slow drying to 20% moisture content (dry basis); they were then immersed in liquid nitrogen for 24 hours and after that, reheated in a water bath. C. arabica seeds have better physiological quality after slow drying, but rapid drying is better for cryopreservation of these seeds. The seeds of the cultivars investigated have different levels of tolerance, but all can be cryopreserved; 'Catuaí Amarelo' is the most tolerant and 'Arara' the most sensitive to cryopreservation, regardless of the drying speed. The activity of the enzymes catalase, peroxidase and esterase increased after drying and after cryopreservation. Rapid drying in silica gel to 20% moisture content, followed by direct immersion in liquid nitrogen, allows cryopreservation of coffee seeds in a fast, simple and economical manner.

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Section: Methodsmentioning

confidence: 99%

Cryopreservation of coffee seeds: a simplified method

Coelho

Rosa

Fernandes

2017

Seed Science and Technology

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“…The seeds were soaked in water for 36 hours for the extraction of the embryos. The embryos extracted, kept in a polyvinylpyrrolidone (PVP) antioxidant solution, were washed in running water, immersed in a 0.5% tetrazolium solution using dark vials and stored at 30 ºC temperature for 3 hours (Brasil, 2009;Clemente et al, 2011). Embryo viability analysis was performed using a stereoscopic magnifying glass with a 10-fold increase for better visualization of the embryos internal (central cylinder) and external structures.…”

Section: Determination Of Survival and Viability Of Coffee Seeds And mentioning

confidence: 99%

Exploratory studies for cryopreservation of Coffea arabica L. seeds

et al. 2017

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-Cryopreservation is a viable option for conservation of coffee germplasm. However, for this technique to be completely successful, it is of fundamental importance to carry out studies that ensure maintenance of cell integrity before and after immersion in liquid nitrogen (LN). Therefore, the aim in this study was to investigate the water content, cooling rate, and final temperature most suitable for cryopreservation of Coffea arabica L. seeds. The seeds were dried by silica gel to water contents of 5, 10, 15, 20, 30 and 40 % wb, subjected to slow cooling treatments at speeds of -1, -3 and -5 °C min.-1 to final temperatures of -40, -50 and -60 °C and then directly immersed in LN. After storage, seeds were rewarmed at 40 °C for two minutes. The survival rate and viability of the seeds and embryos were evaluated by the tetrazolium and germination tests.Results of the tetrazolium test indicate that embryos excised from cryopreserved seeds are less sensitive to cryopreservation than whole seeds are. The water content of 20% wb and the use of zygotic embryos led to the highest survival rate of the coffee seeds, depending on the cooling rate and the final temperature of precooling.Index terms: silica gel, water content, slow cooling, liquid nitrogen, coffee.Estudos exploratórios para a criopreservação de sementes de Coffea arabica L.RESUMO -A criopreservação é uma opção viável para a conservação de germoplasma de café. Entretanto, para que essa técnica apresente total sucesso é de fundamental importância realizar pesquisas que garantam a manutenção da integridade celular antes e após a imersão em NL. Portanto, o objetivo neste estudo foi investigar o teor de água, velocidade e temperatura final de resfriamento mais adequados para criopreservar sementes de Coffea arabica L. As sementes foram secadas em sílica gel até teores de água de 5, 10, 15, 20, 30 e 40% bu, submetidas a tratamentos de resfriamento lento nas velocidades -1, -3 e -5 ºC min -1 até às temperaturas finais de -40, -50 e -60 ºC e diretamente imersas em NL. Após armazenamento as sementes foram reaquecidas por dois minutos à 40 ºC. A sobrevivência e a viabilidade de sementes e embriões foram avaliadas por meio do teste de tetrazólio e de germinação. Por meio do teste de tetrazólio, observa-se que embriões excisados das sementes criopreservadas são menos sensíveis à criopreservação quando comparados às sementes inteiras. O teor de água de 20% bu permite maior sobrevivência das sementes de Coffea arabica L., bem como de embriões zigóticos após a criopreservação, dependendo das velocidades e temperaturas finais de pré-resfriamento.Termos para indexação: sílica gel, teor de água, resfriamento lento, nitrogênio líquido, café.

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“…After this period, the dry matter of roots and shoots of the seedlings was determined, and the results were expressed in milligrams per seedling. Four replications of 10 seeds were used for the tetrazolium test; the seeds were imbibed in distilled water for a period of 48 hours at 30 ºC (Clemente et al, 2011). After this period, the embryos were removed with the aid of a scalpel so as to avoid damaging them.…”

Section: Physiological Evaluationmentioning

confidence: 99%

Tolerance of Coffea arabica L. seeds to sub zero temperatures

et al. 2017

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Preservation of the quality of coffee seeds is hindered by their intermediate behavior in storage. However, long-term storage at sub zero temperatures may be achieved by adjusting the water content of the seeds. The aim of this study was to evaluate the tolerance of coffee seeds to freezing, in relation to physiological and enzymatic modifications. Coffee seeds were dried in two manners, rapid and slow, to water contents of interest, 0.67, 0.43, 0.25, 0.18, 0.11, and 0.05 g H 2 O g -¹ dw (dry basis). After drying, the seeds were stored at a temperature of -20 ºC and of 86 ºC for 24 hours and for 12 months, and then compared to seeds in cold storage at 10 ºC. The seeds were evaluated through calculation of percentage of normal seedlings, percentage of seedlings with expanded cotyledonary leaves, dry matter of roots and of hypocotyls, and viability of embryos in the tetrazolium test. Expression of the enzymes superoxide dismutase, catalase, and peroxidase were evaluated by means of electrophoretic analysis. Only seeds dried more slowly to 0.18 g H 2 O g -1 dw present relative tolerance to storing at -20 °C for 12 months. Coffee seeds do not tolerate storage at a temperature of -86 ºC for 12 months. Water contents below 0.11g H 2 O g -¹ dw and above 0.43 g H 2 O g -¹ dw hurt the physiological quality of coffee seeds, regardless of the type of drying, temperature, and storage period. Coffee seed embryos are more tolerant to desiccation and to freezing compared to whole seeds, especially when the seeds are dried to 0.05 g H 2 O g -¹ dw. The catalase enzyme can be used as a biochemical marker to study tolerance to freezing in coffee seeds.Index terms: Drying; silica gel; saturated saline solutions; freezing; antioxidant enzymes. RESUMOA preservação da qualidade de sementes de café é dificultada pelo comportamento intermediário no armazenamento. Porém, a conservação a longo prazo em temperaturas subzero pode ser conseguido com o ajuste do teor de água das sementes. Objetivou-se neste trabalho avaliar a tolerância de sementes de café ao congelamento, com relação às modificações fisiológicas e enzimáticas. As sementes foram submetidas a dois tipos de secagem, rápida e lenta, até os teores de água de interesse, de 0,67, 0,43, 0,25, 0,18, 0,11, 0,05 g H 2 O g -¹ dw (base seca). Após secagem, as sementes foram armazenadas em temperatura de -20 e de -86 ºC, por 24 horas e por 12 meses, sendo comparadas às sementes armazenadas em câmara fria a 10 ºC. As sementes foram avaliadas pela porcentagem de plântulas normais, plântulas com folhas cotiledonares expandidas, matéria seca de raízes e de hipocótilos e viabilidade dos embriões no teste de tetrazólio. A expressão das enzimas superóxido dismutase, catalase e peroxidase foi avaliada por meio de análise eletroforética. Apenas as sementes secadas lentamente até 0,18 g H 2 O g -¹ dw apresentam relativa tolerância ao armazenamento a -20 °C por 12 meses. Sementes de café não toleram o armazenamento à temperatura de -86 ºC por 12 meses. Umidades abaixo de 0,11g H 2 O g -¹ dw ...

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Preparo das sementes de café para avaliação da viabilidade pelo teste de tetrazólio

Cited by 19 publications

References 4 publications

Cryopreservation of coffee seeds: a simplified method

Cryopreservation of coffee seeds: a simplified method

Exploratory studies for cryopreservation of Coffea arabica L. seeds

Tolerance of Coffea arabica L. seeds to sub zero temperatures

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