A Model for Germination Responses to Alternating Temperatures

Murdoch, A. J.; Roberts, Ε. H.; Goedert, C. O.

doi:10.1093/oxfordjournals.aob.a087733

Cited by 74 publications

(44 citation statements)

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“…Germination experiments were either conducted on a thermogradient table [model GRD1 LH, Grant Instruments Ltd, Cambridge, UK (Murdoch et al, 1989)] or in temperature-controlled incubators.…”

Section: Seed Germinationmentioning

confidence: 99%

Seed dormancy is a dynamic state: variable responses to pre- and post-shedding environmental signals in seeds of contrastingArabidopsisecotypes

2015

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Seeds have evolved to be highly efficient environmental sensors that respond not only to their prevailing environment, but also their environmental history, to regulate dormancy and the initiation of germination. In the present work we investigate the combined impact of a number of environmental signals (temperature, nitrate, light) during seed development on the mother plant, during post-shedding imbibition and during prolonged post-shedding exposure in both dry and imbibed states, simulating time in the soil seed bank. The differing response to these environments was observed in contrasting winter (Cvi, Ler) and summer (Bur) annual Arabidopsis ecotypes. Results presented show that environmental signals both pre-and post-shedding determine the depth of physiological dormancy and therefore the germination response to the ambient environment. The ecotype differences in seed response to ambient germination conditions are greatly enhanced by seed maturation in different environments. Further variation in response develops following shedding when seeds do not receive the full complement of environmental signals required for germination and enter the soil seed bank in either dry or imbibed states. Species seed dormancy characteristics cannot therefore be easily defined, as seed dormancy is a dynamic state subject to within-species adaptation to local environments.

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Section: Seed Germinationmentioning

confidence: 99%

Seed dormancy is a dynamic state: variable responses to pre- and post-shedding environmental signals in seeds of contrastingArabidopsisecotypes

2015

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“…Aparentemente o aumento da amplitude térmica diária possibilitou melhores condições para a germinação; entretanto, observou-se que na ausência de luz apenas o intervalo de temperatura 20-35 ºC manteve os mesmos resultados, enquanto para a temperatura 15-35 ºC houve decréscimo acentuado para ambos os parâmetros. Para as espécies que necessitam de temperaturas alternadas para a germinação das sementes, a amplitude de variação da temperatura aparentemente é mais importante do que os valores absolutos das temperaturas (Murdoch et al, 1989). McDonald et al (1994) reportaram que essa diferença foi de 10 ºC para a germinação da maioria das gramíneas de estações frias, no entanto, a amplitude térmica para a espécie D. ciliaris foi de 15 ºC.…”

Section: Tabela 1 Porcentagem E íNdice De Velocidade De Germinação (unclassified

Efeitos da luz e temperatura na germinação de sementes de quatro espécies de plantas daninhas do gênero Digitaria

Mondo

Carvalho

Dias

et al. 2010

Rev. bras. sementes

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RESUMO -O Brasil é o país das Américas com maior número de espécies nativas do gêneroTermos para indexação: plantas daninhas, capim-colchão, capim-amargoso, análise de sementes. LIGHT AND TEMPERATURE EFFECTS ON THE SEED GERMINATION OF FOURDigitaria WEED SPECIES ABSTRACT -Brazil has the largest number of native species of Digitaria in the Americas. This genus is considered as a weed causing problems in various economic crops and can be found throughout Brazil in many different ecological situations. The object of this research was to evaluate the effects of light and temperature on the seed germination of four Digitaria weed species. The experiment was conducted in germination chambers using a factorial 4 x 2 scheme of treatments under four temperatures (25 ºC

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“…In addition, for each seed, j, there is a threshold temperature, T Hj , below which germination cannot proceed. Previously reported data (Labouriau & Osborn, 1984 ;Ellis et al, 1986 ;Murdoch et al, 1989) suggest that the T Hj are normally distributed N(T H ,σ H # ) ; if so the following equation applies :…”

Section: Mathematical Description Of the Model And Parameter Estimationmentioning

confidence: 99%

Modelling the germination of Stellaria media using the concept of hydrothermal time

Grundy¹,

Phelps²,

Reader³

et al. 2000

New Phytologist

122

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The germination characteristics of Stellaria media (common chickweed) were investigated over a range of constant temperatures and degrees of moisture stress in order to assess the suitability of hydrothermal time as a basis for modelling germination under field conditions. Maximum percentage germination occurred over a much narrower temperature range around the optimum temperature than previously seen for cultivated crop seed. The entire final percentage germination response to temperature in water was well described by two probit curves, and this model was extended to describe the data at all water potentials at a temperature close to the optimum. The implications of the reduction in germination at nonoptimal temperatures are discussed with respect to the interpretation of germination progress curves and conditional dormancy. After adjusting for maximum percentage germination, a hydrothermal time model was found to fit the data set well within the conditions normally encountered in horticultural seedbeds. This separation of the final percentage germination presents a flexible modelling approach that allows for the different levels of dormancy typically expressed within weed populations. By contrast with many previously reported species, S. media had a synchronous germination rate within the population at any given temperature\water potential combination. This synchronous germination of at least a proportion of the population over a wide range of temperature and water potentials might have ecological significance for the opportunistic germination behaviour of this weed species.

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A Model for Germination Responses to Alternating Temperatures

Cited by 74 publications

References 0 publications

Seed dormancy is a dynamic state: variable responses to pre- and post-shedding environmental signals in seeds of contrastingArabidopsisecotypes

Seed dormancy is a dynamic state: variable responses to pre- and post-shedding environmental signals in seeds of contrastingArabidopsisecotypes

Efeitos da luz e temperatura na germinação de sementes de quatro espécies de plantas daninhas do gênero Digitaria

Modelling the germination of Stellaria media using the concept of hydrothermal time

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