Physical dormancy in seeds of six genera of Australian Rhamnaceae

2005 ◽  
Vol 15 (1) ◽  
pp. 51-58 ◽  
Author(s):  
S.R. Turner ◽  
D.J. Merritt ◽  
C.C. Baskin ◽  
K.W. Dixon ◽  
J.M. Baskin
Keyword(s):  
Seed Dormancy ◽  
Restoration Ecology ◽  
Hot Water ◽  
Optimum Temperature ◽  
Physical Dormancy ◽  
South West ◽  
Temperature Regimes ◽  
High Germination

Physical dormancy (PY) was identified in six genera representative of Australian Rhamnaceae and subsequently was broken, based on identification of key seed dormancy characteristics: (1) isolation and classification of embryo features; (2) imbibition experiments to determine the rate and amount of water uptake in seeds; and (3) determination of optimum temperature regimes for germination. All six species had relatively large spatulate embryos. Imbibition studies showed all species possessed PY (i.e. a water-impervious seed coat) that was broken by a hot-water treatment. Alleviation of PY resulted in high germination (<70%) at 7/18°C, temperatures similar to winter in south-west Western Australia. Germination was suppressed at higher temperatures and in the presence of light. The study adds information to our knowledge of seed dormancy in Australian Rhamnaceae, and highlights the benefits of understanding dormancy states in seeds prior to evaluating dormancy-release mechanisms on wild species used in restoration ecology and horticulture.

Seed dormancy in four Tibetan Plateau Vicia species and characterization of physiological changes in response of seeds to environmental factors

2013 ◽  
Vol 23 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Xiaowen Hu ◽  
Tingshan Li ◽  
Juan Wang ◽  
Yanrong Wang ◽  
Carol C. Baskin ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Seed Dormancy ◽  
Germination Rate ◽  
Soil Surface ◽  
The Tibetan Plateau ◽  
Physical Dormancy ◽  
High Germination ◽  
One Year ◽  
Hydrotime Model ◽  
Aba Biosynthesis

AbstractAlthough seed dormancy of temperate legumes is well understood, less is known about it in species that grow in subalpine/alpine areas. This study investigated dormancy and germination of four Vicia species from the Tibetan Plateau. Fresh seeds of V. sativa were permeable to water, whereas those of V. angustifolia, V. amoena and V. unijuga had physical dormancy (PY). One year of dry storage increased the proportion of impermeable seeds in V. angustifolia, but showed no effect on seed coat permeability in V. amoena or V. unijuga. Seeds of all four species also had non-deep physiological dormancy (PD), which was especially apparent in the two annuals at a high germination temperature (20°C). After 1 year of storage, PD had been lost. The hydrotime model showed that fresh seeds obtained a significantly higher median water potential [Ψb(50)] than stored seeds, implying that PD prevents germination in winter for seeds dispersed without PY when water availability is limited. After 6 months on the soil surface in the field, a high proportion of permeable seeds remained ungerminated, further suggesting that PD plays a key role in preventing germination after dispersal. Addition of fluridone, an inhibitor of abscisic acid (ABA) biosynthesis, evened-out the differences in germination between fresh and stored seeds, which points to the key role of ABA biosynthesis in maintaining dormancy. Further, fresh seeds were more sensitive to exogenous ABA than stored seeds, indicating that storage decreased embryo sensitivity to ABA. On the other hand, the gibberellic acid GA3 increased germination rate, which implies that embryo sensitivity to GA is also involved in seed dormancy regulation. This study showed that PY, PD or their combination (PY+PD) plays a key role in timing germination after dispersal, and that different intensities of dormancy occur among these four Vicia species from the Tibetan Plateau.

scholarly journals Effects of soil temperature regimes after fire on seed dormancy and germination in six Australian Fabaceae species

2010 ◽  
Vol 58 (7) ◽  
pp. 539 ◽  
Author(s):  
Victor M. Santana ◽  
Ross A. Bradstock ◽  
Mark K. J. Ooi ◽  
Andrew J. Denham ◽  
Tony D. Auld ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Physical Dormancy ◽  
Temperature Regimes ◽  
Open Canopy ◽  
Eastern Australia ◽  
Soil Temperatures ◽  
Different Depths ◽  
Charred Wood

In addition to direct fire cues such as heat, smoke and charred wood, the passage of fire leads indirectly to changes in environmental conditions which may be able to break physical dormancy in hard-coated seeds. After a fire, the open canopy and the burnt material lying on the surface alter the thermal properties of the soil, resulting in elevated soil temperatures for long periods of time. We simulated daily temperature regimes experienced at different depths of soil profile after a summer fire. Our aim was to determine whether these temperature regimes and the duration of exposure (5, 15 and 30 days) play an important role breaking physical seed dormancy in six legumes from south-eastern Australia. Our results showed that simulated temperature regimes break seed dormancy. This effect is specially pronounced at temperatures that are expected to occur near the soil surface (0–2 cm depth). The duration of exposure interacts with temperature to break dormancy, with the highest germination rates reached after the longest duration and highest temperatures. However, the germination response varied among species. Therefore, this indirect post-fire cue could play a role in the regeneration of plant communities, and could stimulate seedling emergence independent of direct fire cues as well as in interaction with direct cues.

scholarly journals Determination of Different Priming Applications on Vicia freyniana Bronm. Seeds Viability Parametres

2020 ◽  
Author(s):  
O. Yüksel ◽  
B.B. Kenanoğlu ◽  
R.G. Öncü
Keyword(s):  
Research Laboratory ◽  
Germination Rate ◽  
Natural Sciences ◽  
Hot Water ◽  
Hot Water Treatment ◽  
The Third ◽  
Impregnation Technique ◽  
High Germination ◽  
Different Doses

Background: Legumes are the second among all the families in terms of varieties and Vicia genus is the third genus within the Leguminosae family. The germination and emergence rates decrease due to some reasons such as non-homogeneous genetic structure of seed or effect of environmental factors on it. For this reason, some quality problems occur. Quality enhancing applications are performed for seeds to have the desired quality levels in seeds and eliminate the problems. The aim of the present study was to determine the viability of Vicia freyniana Bornm. seeds by different priming treatments. For this purpose, the effect of different chemicals in different doses and periods and at what rate the hot water treatment would affect testa dormancy were studied. Methods: This study was conducted in Uşak University Agriculture and Natural Sciences Faculty Research laboratory in 2019. An investigation was conducted to determine the effects of the priming treatments (Soaking and imbibation; 2, 4 and 6% doses of NaCl, CaCl2 and KNO3 salts and 75, 100 and 125 ppm doses of GA3) on seeds of Vicia freyniana Bornm. In the study, the germination rate (%), germination speed (day), germination index (day) and EC values (µS/cm g-1) of the V. freyniana seeds were determined. Result: The highest germination rates were obtained from 2% of CaCl2 and 75 ppm of GA3 treatments and the fastest germination was observed in KNO3 treatment. From the study, it is concluded that 2% dose of CaCl2 and 75 ppm dose of GA3 should be preferred in V. freyniana seeds and the impregnation technique should be preferred among priming methods due to its high germination performance.

scholarly journals Optimization of Waltheria indica Seed Dormancy Relief Treatments and Seed Storage Parameters

HortScience ◽  
2016 ◽  
Vol 51 (9) ◽  
pp. 1184-1187
Author(s):  
Scott B. Lukas ◽  
Joseph DeFrank ◽  
Orville C. Baldos
Keyword(s):  
Seed Dormancy ◽  
Large Scale ◽  
Heat Exposure ◽  
Seed Storage ◽  
Hot Water ◽  
Physical Dormancy ◽  
Dry Heat ◽  
Long Term Storage ◽  
Viable Seeds ◽  
Temperature Exposure

In Hawaii, Waltheria indica (uhaloa) has been identified for expanded usage as a roadside groundcover in lowland dry ecosystems. Seed dormancy through lack of germination of viable seeds was identified in uhaloa. The presence of physical dormancy in uhaloa seeds was determined and dormancy relief methods were evaluated including hand scarification, dry heat temperature exposure, hot water exposure, and mechanical abrasion in an electric drum scarifier. As a compliment to dormancy relief, long-term storage parameters were evaluated for scarified and nonscarified seeds. The elucidation of physical dormancy was determined through hand scarification, resulting in 96% germination compared with 8% of nonscarified seeds, but is not practical on a large-scale basis. The greatest practical dormancy relief was achieved with a mechanical electric drum scarifier lined with 80-grit sandpaper for a duration of 15 or 30 seconds producing 95% and 99% germination, respectively. Seeds immersed in boiling water for 3 and 5 seconds resulted in 58.6% and 57.7% germination, respectively. Dormancy relief through dry heat exposure was inferior to other relief methods, producing 39% germination at 75 °C for 60 minutes. Nonscarified seeds exhibited minimal loss of viability during 10 months of storage at 5 °C at 12% and 50% relative humidity (RH), but a significant decline in viability of scarified seeds was detected.

THE ESSENCE, THE NEED FOR EVALUATION AND TYPES OF ECONOMIC POTENTIAL OF ENTERPRISES

2017 ◽  
Author(s):  
Olexandr Yemelyanov ◽  
Keyword(s):  
Economic Activity ◽  
Business Strategies ◽  
Enterprise Management ◽  
Value Assessment ◽  
Economic Potential ◽  
Enterprise Value ◽  
Development Assessment ◽  
State Of The Environment

The formation of business strategies of enterprises should be based on a preliminary assessment of their current and future economic opportunities. Such an assessment is to establish the value of the total economic potential of enterprises and its individual varieties. The purpose of this study was to clarify the essence of the economic potential of enterprises, justify the need for its evaluation and selection of its types. The main approaches to interpreting the terms "potential" and "enterprise potential" are identified. These include resource, result, resource-result, resource-target, and result-target concepts. It is established that the potential of any object, including the enterprise, can be interpreted as a set of its external functional properties, which this object shows or can show in a certain state of the environment in which it is located. Accordingly, the assessment of the potential of an object should be based on the identification and determination of its external properties, taking into account the environment in which the object is located. The main situations in which there is a need for information about certain components of the economic potential of the enterprise are identified, and the types of this potential and the consumers of the information about their level, corresponding to these situations, are determined. In particular, such situations include management of production and sales, management of financial and economic results of the enterprise, management of enterprise development, assessment of the company's need for various types of resources, assessment of enterprise value, assessment of current and future impact of the enterprise on the economy of the country (region), etc. The features of classification of types of enterprise potential existing in the scientific literature are supplemented by the following ones: by the main types of economic activity, by the dynamics of changes in the economic and production system of the enterprise, by consequences for the subject of enterprise potential assessment, by the stages of economic activity, enterprise potential, etc. The obtained results make it possible to improve the understanding of the complex patterns that underlie the formation of the economic potential of enterprises.

State Failure and the Political Violence Phenomenon: A Comparative Analysis of Iraq and Syria Cases

2016 ◽  
Vol 4 (2) ◽  
pp. 170 ◽  
Author(s):  
K. Eylem Özkaya Lassalle
Keyword(s):  
Cold War ◽  
Political Violence ◽  
State Failure ◽  
The Political ◽  
Collective Violence ◽  
Short Run ◽  
Definition Of ◽  
The Cold War

The concept of failed state came to the fore with the end of the Cold War, the collapse of the USSR and the disintegration of Yugoslavia. Political violence is central in these discussions on the definition of the concept or the determination of its dimensions (indicators). Specifically, the level of political violence, the type of political violence and intensity of political violence has been broached in the literature. An effective classification of political violence can lead us to a better understanding of state failure phenomenon. By using Tilly’s classification of collective violence which is based on extent of coordination among violent actors and salience of short-run damage, the role played by political violence in state failure can be understood clearly. In order to do this, two recent cases, Iraq and Syria will be examined.

Method of determination of the text direction on the image with the use of convolutional neural network

2020 ◽  
pp. 96-99
Author(s):  
P.L. Nikolaev
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Deep Neural Network ◽  
Binary Classification ◽  
Synthetic Data ◽  
Real Data ◽  
Method Of Determination ◽  
Classification Of Images

This article deals with method of binary classification of images with small text on them Classification is based on the fact that the text can have 2 directions – it can be positioned horizontally and read from left to right or it can be turned 180 degrees so the image must be rotated to read the sign. This type of text can be found on the covers of a variety of books, so in case of recognizing the covers, it is necessary first to determine the direction of the text before we will directly recognize it. The article suggests the development of a deep neural network for determination of the text position in the context of book covers recognizing. The results of training and testing of a convolutional neural network on synthetic data as well as the examples of the network functioning on the real data are presented.

Actual issues of systematization of scientific knowledge on the conditions of shot in the forensic ballistics

2020 ◽  
Vol 2020 (3) ◽  
pp. 164-169
Author(s):  
Igor' Latyshov ◽  
Fedor Samuylenko
Keyword(s):  
Scientific Knowledge ◽  
Communication Systems ◽  
Production Method ◽  
Natural Phenomenon ◽  
Projectile Energy ◽  
Energy Characteristics ◽  
Shot Classification ◽  
Forensic Ballistics

In this research, there was considered a challenge of constructing a system of scientific knowledge of the shot conditions in judicial ballistics. It was observed that there are underlying factors that are intended to ensureits [scientific knowledge] consistency: identification of the list of shot conditions, which require consideration when solving expert-level research tasks on weapons, cartridges and traces of their action; determination of the communication systems in the course of objects’ interaction, which present the result of exposure to the conditions of the shot; classification of the shot conditions based on the grounds significant for solving scientific and practical problems. The article contains the characteristics of a constructive, functional factor (condition) of weapons and cartridges influence, environmental and fire factors, the structure of the target and its physical properties, situational and spatial factors, and projectile energy characteristics. Highlighted are the forms of connections formed in the course of objects’ interaction, proposed are the author’s classifications of forensically significant shooting conditions with them being divided on the basis of the following criteria: production from the object of interaction, production from a natural phenomenon, production method, results weapon operation and utilization, duration of exposure, type of structural connections between interaction objects, number of conditions that apply when firing and the forming traces.

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