Physiology of Seed Germination

Toóle, E. H.; Hendricks, S. B.; Borthwick, and H A; Toole, Vivian K.

doi:10.1146/annurev.pp.07.060156.001503

Cited by 260 publications

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“…It is presumably complex and possibly different among species. Several authors have considered the problem (4,10,17), but no principal concepts have emerged.…”

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confidence: 99%

Phytochrome Control of Germination of Rumex crispus L. Seeds Induced by Temperature Shifts

Taylorson

Hendricks

1972

Plant Physiol.

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High germination of curly dock (Rumex crispus L.) seeds is evident after suitable imbibition and temperature shift treatment, but germination at constant temperatures fails without an input of far red-absorbing form of phytochrome. Preliminary imbibitions at high temperatures (30 C) sharply reduce germination induced by temperature shifts. High germination may be restored by low energies of red radiation, or by brief far red adequate for the photosteady state. Prolonged far red during imbibition also nullifies temperature shift-induced germination. Afer prolonged far red, high germination may be restored by red radiation of an energy dependent upon the duration of the far red treatment. The evidence supports the conclusion that dark germination induced by temperature shifts arises from the interaction of pre-existent far red-absorbing form of phytochrome in the mature seeds with the temperature shift.The extensive use of alternating temperatures as a stimulus to seed germination in routine seed testing is indicative of its effectiveness. The usual alternation' is a diurnal one, from a low temperature to a higher one. The low temperature used is generally more favorable for germination. In some seed kinds, the effect is mainly on rate of germination. In others, such as curly dock (Rumex crispus L.), germination fails if the seeds are incubated at constant temperatures, even after prolonged periods. The mechanism of induction of germination by alternating temperatures remains obscure. It is presumably complex and possibly different among species. Several authors have considered the problem (4, 10, 17), but no principal concepts have emerged.In addition to the fact that Rumex seeds germinate in the dark after alternating temperature treatment, it is known that red illumination will induce germination at constant temperatures (5,8 MATERIALS AND METHODS Seeds of R. crispus were collected near Beltsville, Maryland during July 1970. Preparatory to storage at -10 C in sealed containers, the seeds were gently rubbed to remove enclosing flower parts and cleaned in an air blast seed separator for approximate uniformity in size and weight. The seeds were germinated in 9-cm Petri dishes on filter papers moistened to a shiny appearance with tap water. After planting, the dishes were immediately enclosed in opaque black cloth bags and placed in dark incubators maintained at + 1 C of the designated temperature. Seeds were kept in darkness throughout, except during specified light treatments.Temperature shift treatments of the variously imbibed seeds were normally made by manual transfers to a 35 C incubator for 2 hr. Following the temperature shift, the seeds were returned to 20 C for 22 hr and the temperature shift then repeated. Germination was recorded after an additional 4 days at 20 C. R' was obtained from a cool white fluorescent source filtered to give broad-band R radiation (600-680 nm) of 0.099 mw cm'2 at the working distance of 1 m. Brief (5 min) FR irradiation was from incandescent sources filtered to give ra...

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“…It is presumably complex and possibly different among species. Several authors have considered the problem (4,10,17), but no principal concepts have emerged.…”

mentioning

confidence: 99%

Phytochrome Control of Germination of Rumex crispus L. Seeds Induced by Temperature Shifts

Taylorson

Hendricks

1972

Plant Physiol.

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“…This process divided into three distinct stages which are imbibition, cell elongation and cell division [10] each one leading to the next. These processes are associated with the formation and utilization of enzymes which mediate crucial biochemical transformations such as the conversion of stored proteins, carbohydrates or oils depending on the kind of seed in the endosperm to simple ready-to-use substances used to fuel primary growth.…”

Section: Germination Tests Of Three Landraces Of Phaseolus Vulgaris Tmentioning

confidence: 99%

Mutagenic Action of Sodium Azide on Germination and Emergence in Landraces of Phaseolus vulgaris L.on the Jos Plateau Agro-Ecological Zone

Liamngee¹,

JeremiahOgah²,

Amagu³

et al. 2017

IOSR JAVS

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“…Sementes dormentes de algumas espécies requerem altas tensões de oxigênio para a germinação, provavelmente devido à presença de inibidores no tegumento, os quais reduzem a absorção de gases, sem contudo, afetar a taxa de absorção de água pelas mesmas (Toole et al, 1956). Esses autores abordaram que a substância inibidora da germinação pode ocorrer tanto no tegumento como no embrião.…”

Section: Introductionunclassified

Determinação de inibidores da germinação no espermoderma de sementes de café (Coffea arabica L.)

Pereira¹,

Oliveira²,

Lúcia³

et al. 2002

Rev. bras. sementes

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E ANA LÚCIA PEREIRA KIKUTI 5 RESUMO -Sementes de café apresentam germinação lenta, aumentando consequentemente o período de formação das mudas. A causa dessa germinação lenta, ainda não está elucidada. Aparentemente, a difusão de gases e da água tem papel secundário comparadas ao efeito de inibidores presentes. A presente pesquisa foi desenvolvida no Setor de Sementes do Departamento de Agricultura e no Laboratório de Química da Universidade Federal de Lavras. Em uma pesquisa preliminar, utilizando sementes de alface como indicadora de inibidores e extrato aquoso de espermoderma ("película prateada"), ficou evidenciada a presença de inibidores nesse tecido. Em uma segunda etapa o extrato aquoso da película prateada foi submetido a um fracionamento, em teste in vitro. Observou-se, por meio desse teste, que a fração ativa encontrava-se na fase metanólica, a qual foi concentrada sob vácuo e eluída através de coluna de sílica gel com metanol, água destilada e HCl 0,1M. Após concentração sob vácuo da fração ativa originou-se um sólido branco, que se mostrou homogêneo segundo análise por cromatografia em camada fina com placas de sílica gel. Por meio de análise de espectrometria de infravermelho, de massas e de ressonância magnética nuclear de 1 H e de 13 C, atribuiu-se a tal sólido a estrutura da cafeína. Conclui-se que o espermoderma pode contribuir para a lenta germinação das sementes de café, possivelmente devido à presença de cafeína.Termos para indexação: sementes, café, germinação, inibidores. GERMINATION INHIBITORS DETERMINATION IN THE SPERMODERM OF COFFEE (Coffea arabica L.) SEEDSABSTRACT -Coffee seeds present slow germination, increasing hence the period of formation of seedlings. The cause that slow germination is not elucidated yet. Apparently, the diffusion of gases and water has a secondary role as compared with the effect of inhibitors present. The present research work was developed in the Seed Sector of the Agriculture Department and in the Chemistry Department of the Universidade Federal de Lavras. In a previous research by utilizing lettuce seeds as an indicator of inhibitors and aqueous extract of spermoderm (silvery film), the presence of inhibitors in this tissue was evidenced. In a second step, the aqueous step of the silvery film was submitted to a fractionating, in vitro test. It was observed by means of that test, that the active fraction was in the methanol phase, which was concentrated under vacuum and eluted through gel silica column with methanol, distilled water and 0.1M HCl. After concentration under vacuum, of active fraction gave rised to a white solid, which showed itself homogenous according to the thin layer chromatography analysis with gel silica plates. By means of the infrared, mass and 1 H and 13 C nuclear magnetic resonance spectrometry, the caffeine structure was ascribed to such a solid. It follows that spermoderm may contribute to the slow germination of coffee seeds, possibly due to the presence of caffeine.

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Physiology of Seed Germination

Cited by 260 publications

References 0 publications

Phytochrome Control of Germination of Rumex crispus L. Seeds Induced by Temperature Shifts

Phytochrome Control of Germination of Rumex crispus L. Seeds Induced by Temperature Shifts

Mutagenic Action of Sodium Azide on Germination and Emergence in Landraces of Phaseolus vulgaris L.on the Jos Plateau Agro-Ecological Zone

Determinação de inibidores da germinação no espermoderma de sementes de café (Coffea arabica L.)

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