Temperature Coefficient (Q10), Seed Germination and Other Biological Processes

Hegarty, T. W.

doi:10.1038/243305a0

Cited by 76 publications

(50 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A linear relationship between rates of plant development and temperature was first made prominent by Hegarty (1973). Since then, linear relationships have been extensively applied to studies with cultivated but not with wild plants.…”

Section: mentioning

confidence: 99%

A thermal time basis for comparing the germination requirements of some British herbaceous plants

Squire¹,

Thompson²

2000

New Phytologist

View full text Add to dashboard Cite

The effect of temperature on germination rate was assessed for seeds of 31 wild plant species and four cultivated species growing in the UK. The temperature at which seed first germinated ranged from 2mC (Brassica rapa) to 11mC (several species). As the temperature progressively increased, the percentage of seed that germinated rapidly increased to near 100%, whereas the duration for germination progressively decreased up to the thermal optimum. Above the thermal optimum, the duration for germination initially remained constant, and then rapidly increased until the thermal maximum was exceeded when no seed germinated. To assess the effect of temperature on germination rates, the reciprocal of the duration (1\duration) for 50% germination was calculated and regressed against temperature. For most species a linear regression accounted for 90% of the variation in germination rates for temperatures up to the thermal optimum. From the regressions, the base temperatures (T b , below which no germination is expected) and the thermal constant (S, expressed in degree days) for 50% germination were calculated. The extremes were the alpine species Dryas octopetala, which had a high T b (c. 12.0mC) and low S (26 degree days), and Saxifraga tridactylites which had a low estimated T b (c. k1.8mC) and a high S (136 degree days). The estimated value of S increased with increasing percentage germination, and although S varied considerably between species with similar values of T b , a weak inverse relationship between T b and S was indicated. A thermal time approach was shown to be useful when analysing and comparing thermal requirements for germination of the seed of wild plant species. It showed, for example, that percentage germination often decreased as temperatures approached T b , and that for some seed germination ceased at temperatures well above T b .

show abstract

Section: mentioning

confidence: 99%

A thermal time basis for comparing the germination requirements of some British herbaceous plants

Squire¹,

Thompson²

2000

New Phytologist

View full text Add to dashboard Cite

show abstract

“…The rate of germination (defined as the reciprocal of the time taken for 50% seeds to germinate) usually increases linearly with temperature in the suboptimal range and then decreases linearly [8][9][10]. Garcia-Huidobro et al [11] developed a linear thermal time model (TT model) to calculate the cardinal temperatures and the thermal time constant at suboptimal (θ1(g)) and supraoptimal temperatures (θ2(g)) of different subpopulations (germination fractions/percentiles) g in a seed lot.…”

Section: Introductionmentioning

confidence: 99%

A Modified Thermal Time Model Quantifying Germination Response to Temperature for C3 and C4 Species in Temperate Grassland

2015

View full text Add to dashboard Cite

Thermal-based germination models are widely used to predict germination rate and germination timing of plants. However, comparison of model parameters between large numbers of species is rare. In this study, seeds of 27 species including 12 C4 and 15 C3 species were germinated at a range of constant temperatures from 5 °C to 40 °C. We used a modified thermal time model to calculate germination parameters at suboptimal temperatures. Generally, the optimal germination temperature was higher for C4 species than for C3 species. The thermal time constant for the 50% germination percentile was significantly higher for C3 than C4 species. The thermal time constant of perennials was significantly higher than that of annuals. However, differences in base temperatures were not significant between C3 and C4, or annuals and perennial species. The relationship between germination rate and seed mass depended on plant functional type and temperature, while the base temperature and thermal time constant of C3 and C4 species exhibited no significant relationship with seed mass. The results illustrate differences in germination characteristics between C3 and C4 species. Seed mass does not affect germination parameters, plant life cycle matters, however.

show abstract

“…The germination rate usually increases linearly with temperature within the suboptimal temperature range (Hegarty 1973, Bierhuizen & Wagenvoort 1974, Dau & Labouriau 1974, Thompson & Fox 1976, Whashitani & Takenaka 1984, Perez & Moraes 1990. As shown in the fi gure 2, up to 35 °C the germination rates increased linearly with temperature, the intercept is at 9 °C which differs from the experimental minimum that is between 10 ° and 15 °C.…”

Section: Discussionmentioning

confidence: 99%

Isothermal seed germination of Adenanthera pavonina

Zpevak¹,

Gualtieri²,

Buckeridge

2012

Braz. J. Bot.

View full text Add to dashboard Cite

-(Isothermal seed germination of Adenanthera pavonina). This work reports aspects of seed germination at different temperatures of Adenanthera pavonina L., a woody Southeast Asian Leguminosae. Germination was studied by measuring the fi nal percentages, the rate, the rate variance and the synchronisation of the individual seeds calculated by the minimal informational entropy of frequencies distribution of seed germination. Overlapping the germinability range with the range for the highest values of germination rates and the minimal informational entropy of frequencies distribution of seed germination, we found that the best temperature for the germination of A. pavonina seeds is 35 °C. The slope μ of the Arrhenius plot of the germination rates is positive for T < 35 °C and negative for T > 35 °C. The activation enthalpies, estimated from closely-spaced points, shows that |∆H-| < 12 Cal mol -1 occur for temperatures in the range between 25 °C and 40 °C. The ecological implication of these results are that this species may germinate very fast in tropical areas during the summer season. This may be an advantage to the establishment of this species under the climatic conditions in those areas.

show abstract

Temperature Coefficient (Q10), Seed Germination and Other Biological Processes

Cited by 76 publications

References 2 publications

A thermal time basis for comparing the germination requirements of some British herbaceous plants

A thermal time basis for comparing the germination requirements of some British herbaceous plants

A Modified Thermal Time Model Quantifying Germination Response to Temperature for C3 and C4 Species in Temperate Grassland

Isothermal seed germination of Adenanthera pavonina

Contact Info

Product

Resources

About