Multiple environmental signals required for embryo growth and germination of seeds of Selinum carvifolia (L.) L. and Angelica sylvestris L. (Apiaceae)

AbstractGermination and dormancy breaking requirements were studied in Selinum carvifolia (L.) L. and Angelica sylvestris L. (Apiaceae). Seeds of these two species have an underdeveloped embryo and are morpho-physiologically dormant. The embryo does not start to grow until physiological dormancy is broken by cold stratification. Incubating seeds at fluctuating temperatures in the light, after cold stratification, had a stimulating effect on embryo growth and seed germination. Seeds of S. carvifolia and A. sylvestris have non-deep simple morphophysiological dormancy (MPD), since gibberellic acid (GA3) could substitute for cold stratification. This is the first report of non-deep simple MPD that is broken by cold stratification in the Apiaceae. Under natural conditions, physiological dormancy is broken by low temperature conditions during winter. Embryo growth and germination occur in a short time interval when temperatures start rising in early spring. Due to the fact that multiple environmental signals regulate dormancy, seedling emergence in these species is timed very accurately in spring.

Download Full-text

Morphological and physiological dormancy in seeds of Aegopodium podagraria (Apiaceae) broken successively during cold stratification

Seed Science Research ◽

10.1017/s0960258509301075 ◽

2009 ◽

Vol 19 (2) ◽

pp. 115-123 ◽

Cited By ~ 14

Author(s):

Filip Vandelook ◽

Nele Bolle ◽

Jozef A. Van Assche

Keyword(s):

Low Temperature ◽

Seedling Emergence ◽

Early Spring ◽

Temperate Climate ◽

Cold Stratification ◽

Dormancy Breaking ◽

Morphophysiological Dormancy ◽

Temperature Requirement ◽

Physiological Dormancy ◽

Chilling Period

AbstractA low-temperature requirement for dormancy break has been observed frequently in temperate-climate Apiaceae species, resulting in spring emergence of seedlings. A series of experiments was performed to identify dormancy-breaking requirements of Aegopodium podagraria, a nitrophilous perennial growing mainly in mildly shaded places. In natural conditions, the embryos in seeds of A. podagraria grow in early winter. Seedlings were first observed in early spring and seedling emergence peaked in March and April. Experiments using temperature-controlled incubators revealed that embryos in seeds of A. podagraria grow only at low temperatures (5°C), irrespective of a pretreatment at higher temperatures. Seeds did not germinate immediately after embryo growth was completed, instead an additional cold stratification period was required to break dormancy completely. Once dormancy was broken, seeds germinated at a range of temperatures. Addition of gibberellic acid (GA3) had a positive effect on embryo growth in seeds incubated at 10°C and at 23°C, but it did not promote germination. Since seeds of A. podagraria have a low-temperature requirement for embryo growth and require an additional chilling period after completion of embryo growth, they exhibit characteristics of deep complex morphophysiological dormancy.

Download Full-text

Seeds of Thalictrum mirabile (Ranunculaceae) require cold stratification for loss of nondeep simple morphophysiological dormancy

Canadian Journal of Botany ◽

10.1139/b99-149 ◽

2000 ◽

Vol 77 (12) ◽

pp. 1769-1776 ◽

Cited By ~ 9

Author(s):

Jeffrey L Walck ◽

Carol C Baskin ◽

Jerry M Baskin

Keyword(s):

Gibberellic Acid ◽

Seed Bank ◽

Soil Seed Bank ◽

Early Spring ◽

Late Winter ◽

Cold Stratification ◽

Morphophysiological Dormancy ◽

Physiological Dormancy ◽

Buried Seeds ◽

Persistent Soil Seed Bank

Seeds of the eastern North American herbaceous polycarpic perennial Thalictrum mirabile Small have differentiated but underdeveloped (small) embryos that are physiologically dormant at maturity in September. Physiological dormancy was broken effectively by cold stratification at 1°C, but embryos required temperatures [Formula: see text]15:6°C for growth after physiological dormancy was broken. Gibberellic acid substituted for cold stratification. Breaking of physiological dormancy in seeds exposed to natural temperatures in a greenhouse occurred during winter, and embryo growth and germination occurred in late winter - early spring. Furthermore, seeds in the greenhouse remained viable until the second and third (spring) germination seasons. Thus, T. mirabile seeds have the capacity to form a short-lived persistent soil seed bank. Buried seeds of T. mirabile apparently go through an annual dormancy-nondormancy cycle. Seeds buried in September 1994 were nondormant when exhumed in April 1995 and April 1996 and incubated in light at 25:15°C for 2 weeks, but they were dormant in June 1995 and September 1995. Seeds of T. mirabile have nondeep simple morphophysiogical dormancy. This is the first report of nondeep simple morphophysiological dormancy being broken by cold, and not by warm, stratification.

Download Full-text

Dormancy-breaking and germination requirements for seeds of Diervilla lonicera (Caprifoliaceae), a species with underdeveloped linear embryos

Canadian Journal of Botany ◽

10.1139/b00-094 ◽

2000 ◽

Vol 78 (9) ◽

pp. 1199-1205 ◽

Cited By ~ 5

Author(s):

Siti N Hidayati ◽

Jerry M Baskin ◽

Carol C Baskin

Keyword(s):

Seed Dormancy ◽

Constant Darkness ◽

Cold Stratification ◽

Dormancy Breaking ◽

Morphophysiological Dormancy ◽

Germination Phenology ◽

Physiological Dormancy ◽

Temperature Controlled ◽

Germination Requirements ◽

Morphological Dormancy

Dormancy-breaking requirements and type of dormancy were determined for seeds of Diervilla lonicera Mill. Seeds have an underdeveloped linear embryo that is about 35% of the length of the seed at maturity. Embryos (in intact seeds) grew at 25:15°C but not at 5°C. Up to 85% of the freshly matured seeds had morphological dormancy (MD), and thus, they germinated within about 30 days on a moist substrate in light at 30:15°C; a maximum of 3% of the seeds germinated in constant darkness. The other portion of fresh seeds had nondeep simple morphophysiological dormancy (MPD) and required a period of warm stratification or treatment with GA3 to break dormancy. These seeds also required light to germinate. In contrast, cold stratification induced dormancy, and dry storage for up to 1 year did not effectively break dormancy. Seeds with MD germinated to significantly higher percentages on soil than on filter paper or on sand. Seeds sown on soil in a non-temperature-controlled greenhouse in mid-November germinated mostly in late May, whereas those sown in mid-April germinated in early May. Apparently, embryos of November-sown seeds were induced into physiological dormancy during winter. Thus, seeds had MPD in spring and needed several weeks of warm temperatures for dormancy break, embryo growth, and germination. This is the first report on seed dormancy in the genus Diervilla.Key words: embryo growth, germination phenology, Diervilla lonicera, morphological seed dormancy, morphophysiological seed dormancy, underdeveloped linear embryo.

Download Full-text

Relation between Verbal Estimation and Reproduction of a Short Time Interval: Preliminary Study

Perceptual and Motor Skills ◽

10.2466/pms.1963.17.1.45 ◽

1963 ◽

Vol 17 (1) ◽

pp. 45-46 ◽

Cited By ~ 4

Author(s):

P. D. Du Preez

Keyword(s):

Time Interval ◽

Short Time Interval ◽

Verbal Estimation ◽

Preliminary Study ◽

Short Time

Download Full-text

Estimation of Time-Dependent Turning Fractions at Signalized Intersections

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1644-15 ◽

1998 ◽

Vol 1644 (1) ◽

pp. 142-149 ◽

Cited By ~ 6

Author(s):

Gang-Len Chang ◽

Xianding Tao

Keyword(s):

Signalized Intersections ◽

Efficient Estimation ◽

Estimation Accuracy ◽

Time Interval ◽

Short Time Interval ◽

Simulation Experiments ◽

Proposed Model ◽

Short Time ◽

Estimation Of Time ◽

Additional Constraints

An effective method for estimating time-varying turning fractions at signalized intersections is described. With the inclusion of approximate intersection delay, the proposed model can account for the impacts of signal setting on the dynamic distribution of intersection flows. To improve the estimation accuracy, the use of preestimated turning fractions from a relatively longer time interval has been proposed to serve as additional constraints for the same estimation but over a short time interval. The results of extensive simulation experiments indicated that the proposed method can yield sufficiently accurate as well as efficient estimation of dynamic turning fractions for signalized intersections.

Download Full-text

Micro-Expression Recognition using 3D - CNN

10.54216/fpa.010101 ◽

2020 ◽

pp. 5-13

Author(s):

Vishal Dubey ◽

◽

Bhavya Takkar ◽

...

Keyword(s):

Emotional Response ◽

High Speed ◽

Actual State ◽

Time Interval ◽

Short Time Interval ◽

Expression Recognition ◽

Specific Emotion ◽

3D Cnn ◽

Short Time ◽

Micro Expression

Micro-expression comes under nonverbal communication, and for a matter of fact, it appears for minute fractions of a second. One cannot control micro-expression as it tells about our actual state emotionally, even if we try to hide or conceal our genuine emotions. As we know that micro-expressions are very rapid due to which it becomes challenging for any human being to detect it with bare eyes. This subtle-expression is spontaneous, and involuntary gives the emotional response. It happens when a person wants to conceal the specific emotion, but the brain is reacting appropriately to what that person is feeling then. Due to which the person displays their true feelings very briefly and later tries to make a false emotional response. Human emotions tend to last about 0.5 - 4.0 seconds, whereas micro-expression can last less than 1/2 of a second. On comparing micro-expression with regular facial expressions, it is found that for micro-expression, it is complicated to hide responses of a particular situation. Micro-expressions cannot be controlled because of the short time interval, but with a high-speed camera, we can capture one's expressions and replay them at a slow speed. Over the last ten years, researchers from all over the globe are researching automatic micro-expression recognition in the fields of computer science, security, psychology, and many more. The objective of this paper is to provide insight regarding micro-expression analysis using 3D CNN. A lot of datasets of micro-expression have been released in the last decade, we have performed this experiment on SMIC micro-expression dataset and compared the results after applying two different activation functions.

Download Full-text

Inter-rater and inter-device reliability of mechanical thresholds measurement with the Electronic von Frey Anaesthesiometer and the SMALGO in healthy cats

Journal of Feline Medicine and Surgery ◽

10.1177/1098612x18813426 ◽

2018 ◽

Vol 21 (10) ◽

pp. 979-984 ◽

Cited By ~ 2

Author(s):

Chiara Adami ◽

Elena Lardone ◽

Paolo Monticelli

Keyword(s):

Small Animal ◽

Time Interval ◽

Short Time Interval ◽

Sensory Thresholds ◽

Additional Tool ◽

Bland Altman Method ◽

Device Reliability ◽

Short Time ◽

Mechanical Thresholds ◽

Level Of Agreement

Objectives The aim of this study was to compare the Electronic von Frey Anaesthesiometer (EVF) and the Small Animal ALGOmeter (SMALGO), used to measure sensory thresholds in 13 healthy cats at both the stifle and the lumbosacral joint, in terms of inter-rater and inter-device reliability. Methods Two independent observers carried out the sets of measurements in a randomised order, with a 45 min interval between them, in each cat. The inter-rater and inter-device reliability were evaluated by calculating the inter-rater correlation coefficient (ICC) for each pair of measurements. The Bland–Altman method was used as an additional tool to assess the level of agreement between the two algometers. Results The mean ± SD sensory thresholds measured with the EVF were 311 ± 116 g and 378 ± 178 g for the stifle and for the lumbosacral junction, respectively, whereas those measured with the SMALGO were 391 ±172 g and 476 ± 172 g. The inter-rater reliability was fair (ICC >0.4) for each pair of measurements except those taken at the level of the stifle with the SMALGO, for which the level of agreement between observers A and B was poor (ICC = 0.01). The inter-device reliability was good (ICC = 0.73; P = 0.001). The repetition of the measurements affected reliability, as the thresholds obtained after the 45 min break were consistently lower than those measured during the first part of the trial ( P = 0.02). Conclusions and relevance The EVF and the SMALGO may be used interchangeably in cats, especially when the area to be tested is the lumbosacral joint. However, when the thresholds are measured at the stifle, the inter-observer reliability is better with the EVF than with the SMALGO. The reliability decreases when the measurements are repeated within a short time interval, suggesting a limited clinical applicability of quantitative sensory testing with both algometers in cats.

Download Full-text

Approximate exit probabilities for a Brownian bridge on a short time interval, and applications

Advances in Applied Probability ◽

10.2307/1427195 ◽

1989 ◽

Vol 21 (1) ◽

pp. 1-19 ◽

Cited By ~ 7

Author(s):

H. R. Lerche ◽

D. Siegmund

Keyword(s):

Virial Coefficient ◽

Large Deviation ◽

Brownian Bridge ◽

Exit Time ◽

Second Virial Coefficient ◽

Dimensional Euclidean Space ◽

Time Interval ◽

Short Time Interval ◽

First Exit Time ◽

Short Time

Let T be the first exit time of Brownian motion W(t) from a region ℛ in d-dimensional Euclidean space having a smooth boundary. Given points ξ0 and ξ1 in ℛ, ordinary and large-deviation approximations are given for Pr{T < ε |W(0) = ξ0, W(ε) = ξ 1} as ε → 0. Applications are given to hearing the shape of a drum and approximating the second virial coefficient.

Download Full-text

Non-Deep Physiological Dormancy in Seed and Germination Requirements of Lysimachia coreana Nakai

Horticulturae ◽

10.3390/horticulturae7110490 ◽

2021 ◽

Vol 7 (11) ◽

pp. 490

Author(s):

Saeng Geul Baek ◽

Jin Hyun Im ◽

Myeong Ja Kwak ◽

Cho Hee Park ◽

Mi Hyun Lee ◽

...

Keyword(s):

Seed Germination ◽

Seed Dormancy ◽

Germination Rate ◽

Seed Viability ◽

Cold Stratification ◽

Dormancy Breaking ◽

Viability Test ◽

Physiological Dormancy ◽

Different Temperatures ◽

Germination Requirements

This study aimed to determine the type of seed dormancy and to identify a suitable method of dormancy-breaking for an efficient seed viability test of Lysimachia coreana Nakai. To confirm the effect of gibberellic acid (GA3) on seed germination at different temperatures, germination tests were conducted at 5, 15, 20, 25, 20/10, and 25/15 °C (12/12 h, light/dark), using 1% agar with 100, 250, and 500 mg·L−1 GA3. Seeds were also stratified at 5 and 25/15 °C for 6 and 9 weeks, respectively, and then germinated at the same temperature. Seeds treated with GA3 demonstrated an increased germination rate (GR) at all temperatures except 5 °C. The highest GR was 82.0% at 25/15 °C and 250 mg·L−1 GA3 (4.8 times higher than the control (14.0%)). Additionally, GR increased after cold stratification, whereas seeds did not germinate after warm stratification at all temperatures. After cold stratification, the highest GR was 56.0% at 25/15 °C, which was lower than the GR observed after GA3 treatment. We hypothesized that L. coreana seeds have a non-deep physiological dormancy and concluded that 250 mg·L−1 GA3 treatment is more effective than cold stratification (9 weeks) for L. coreana seed-dormancy-breaking.

Download Full-text