scholarly journals Effect of colour and size grading of China aster (Callistephus chinensis Nees) seeds on their germination

2012 ◽  
Vol 62 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Agnieszka Rosińska ◽  
Grzegorz Rosiński ◽  
Roman Hołubowicz
Keyword(s):  
Seed Testing ◽  
Royal Horticultural Society ◽  
China Aster ◽  
Colour Chart ◽  
Size Grading ◽  
Better Than

Seeds of 3 commercial China aster (<i>Callistephus chinensis</i> Nees) lots were divided by hand into 3 grades with different colours: dark brown, brown and light brown, and 2 grades with a different size: length below 3.9 mm (small) and above 3.9 mm (large). The colour grading was done based on the Royal Horticultural Society Colour Chart and size grading was done by hand for each seed. Then, seeds were routinely germinated based on the International Seed Testing Association (ISTA) rules. The size of seeds had no effect on their germination. The dark brown seeds germinated better than the light brown ones. Removing light brown seeds from the China aster seed lot improved their germination.

scholarly journals Understanding Alstroemeria pallida Flower Colour: Links between Phenotype, Anthocyanins and Gene Expression

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 55
Author(s):  
Amanda Donoso ◽  
Constanza Rivas ◽  
Alan Zamorano ◽  
Álvaro Peña ◽  
Michael Handford ◽  
...  
Keyword(s):  
High Performance ◽  
Chalcone Synthase ◽  
Ornamental Plants ◽  
Flower Colour ◽  
Anthocyanin Content ◽  
Anthocyanidin Synthase ◽  
Visual Evaluation ◽  
Royal Horticultural Society ◽  
Polymerase Chain ◽  
Colour Chart

Flower colour is mainly due to the accumulation of flavonoids, carotenoids and betalains in the petals. Of these pigments, flavonoids are responsible for a wide variety of colours ranging from pale yellow (flavones, flavonols and flavanodiols) to blue-violet (anthocyanins). This character plays a crucial ecological role by attracting and guiding pollinators. Moreover, in the ornamental plants market, colour has been consistently identified as the main feature chosen by consumers when buying flowers. Considering the importance of this character, the aim of this study was to evaluate flower colour in the native Chilean geophyte Alstroemeria pallida, by using three different approaches. Firstly, the phenotype was assessed using both a colour chart and a colourimeter, obtaining CIELab parameters. Secondly, the anthocyanin content of the pigmented tepals was evaluated by high-performance liquid chromatography (HPLC), and finally, the expression of two key flavonoid genes, chalcone synthase (CHS) and anthocyanidin synthase (ANS) was analysed using real-time polymerase chain reaction (PCR). Visual evaluation of A. pallida flower colour identified 5 accessions, ranging from white (Royal Horticultural Society (RHS) N999D) to pink (RHS 68C). Moreover, this visual evaluation of the accessions correlated highly with the CIELab parameters obtained by colourimetry. An anthocyanidin corresponding to a putative 6-hydroxycyanidin was identified, which was least abundant in the white accession (RHS N999D). Although CHS was not expressed differentially between the accessions, the expression of ANS was significantly higher in the accession with pink flowers (RHS 68C). These results suggest a correlation between phenotype, anthocyanin content and ANS expression for determining flower colour of A. pallida, which could be of interest for further studies, especially those related to the breeding of this species with ornamental value.

scholarly journals A Comparison of the Three Editions of the Royal Horticultural Society Colour Chart

HortScience ◽  
1998 ◽  
Vol 33 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Donald H. Voss ◽  
William N. Hale
Keyword(s):  
Royal Horticultural Society ◽  
Colour Chart

scholarly journals Measuring Camellia Petal Color Using a Portable Color Sensor

Horticulturae ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 53
Author(s):  
Phillip C. Post ◽  
Mark A. Schlautman
Keyword(s):  
Human Error ◽  
Color Space ◽  
Flowering Plants ◽  
Color Variation ◽  
Camellia Japonica ◽  
Color Sensor ◽  
Royal Horticultural Society ◽  
Multiple Measurements ◽  
Colour Chart ◽  
Rhs Colour Chart

The color of petals of flowering plants is often determined by comparing one or more of the petals to various Royal Horticultural Society (RHS) Colour Chart cards until a color match is found. However, these cards are susceptible to fading with age and can also provide inaccurate results if lighting is not optimal. The cards also rely on the human eye to determine a match, which introduces the possibility of human error. The objectives of this study were to determine camellia (Camellia japonica L.) petal color using the RHS Colour Chart, to determine camellia petal color with the NixTM Pro color sensor (Nix Sensor Ltd., Hamilton, Ontario, Canada), and to compare these measurements using different color measuring approaches. Color measurements of camellia flower petals using the NixTM Pro color sensor were compared to published CIELAB values from the Royal Horticultural Society (RHS) Colour Chart. Forty-five petal color samples were collected from fifteen different camellia shrubs. The RHS Colour Chart was used for each of the petals, and the RHS identifications were recorded. Measurements using the NixTM Pro color sensor were compared to RHS-provided CIELAB values that corresponded with the recorded identification for each petal to determine accuracy. The NixTM Pro color sensor’s measurements were also compared to a mean of the values, multiple measurements on the same petal location, and multiple measurements on different petal locations to determine precision and variation. The Nix™ Pro color sensor’s readings were precise in petal color determination and provided more nuanced differences between petals of the same plant and plants of the same variety in each of the color categories. The RHS Colour Chart provided an accurate depiction of most petals, but it was difficult to use with petals that had wide color variation over the entire petal. The Nix™ Pro color sensor’s measurements appeared to have more variation in the b* color space. However, overall, the Nix™ Pro color sensor L*, a*, and b* values were highly correlated with the provided RHS values (p < 0.01), showing that the sensor can be used as an accurate and precise substitute for the RHS Colour Chart. The Nix™ Pro color sensor can be a useful, cost-effective tool to measure the petal color of camellia and other flowering plants and rectifies many of the problems associated with the RHS Colour Chart.

scholarly journals Experimental Paper. The effect of colour grading of milk thistle (Silybum marianum (L.) Gaertn.) seeds on their quality for sowing

2017 ◽  
Vol 63 (1) ◽  
pp. 7-19 ◽  
Author(s):  
Agnieszka Rosińska ◽  
Hanna Dorna ◽  
Dorota Szopińska ◽  
Katarzyna Seidler-Łożykowska
Keyword(s):  
Seed Weight ◽  
Milk Thistle ◽  
Silybum Marianum ◽  
Three Samples ◽  
Royal Horticultural Society ◽  
Final Count ◽  
Fourth Sample ◽  
Quality Of Milk ◽  
Colour Chart

Summary Introduction: Milk thistle (Silybum marianum (L.) Gaertn.) is a medicinal plant belonging to Asteraceae family. Extract from milk thistle achenes (termed in practice as seeds) contains sylimarin, which protects liver cells against inorganic and organic toxic compounds. Objective: The aim of the research was to evaluate the effect of colour grading on the quality of milk thistle seeds. Methods: Seeds were graded manually by colour according to the Royal Horticultural Society Colour Chart, issued in Great Britain. In three samples two fractions of seeds were separated: beige and brown, whereas seeds of the fourth sample were graded into three fractions: yellow, beige and brown. The 1000-seed weight and germination of graded and non-graded seeds were evaluated. Infestation of graded seeds with fungi was assessed. Results: Brown seeds had a higher 1000-seed weight than beige or yellow ones. Germination at the final count of beige seeds did not differ as compared to that of brown seeds or was even better. Milk thistle seeds were infested with numerous fungi, however Alternaria alternata and Ulocladium consortiale predominated. Conclusions: Less mature beige seeds can be used as sowing material because their germination at the final count did not differ as compared to that of fully mature brown seeds or was even better. Infestation of these seeds with some of the fungi was lower than brown seeds.

scholarly journals 225 Growth and Aesthetic Evaluations of Container- and Field-grown Atlantic White Cedar, Chamaecyparis thyoides (L.) B.S.P.

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 429F-430
Author(s):  
David R. Sandrock ◽  
Jean Williams-Woodward ◽  
Michael A. Dirr
Keyword(s):  
Growth Rate ◽  
Growth Habit ◽  
Field Plot ◽  
White Cedar ◽  
Chamaecyparis Thyoides ◽  
Atlantic White Cedar ◽  
Royal Horticultural Society ◽  
Slow Growing ◽  
Colour Chart ◽  
Color Texture

Fifty-four taxa of Atlantic white cedar [Chamaecyparis thyoides (L.) B.S.P.] were assembled and maintained. A protocol for propagation of Atlantic white cedar was established. Plants were grown in containers and in a replicated field plot. Height and width data were recorded from container- and field-grown plants and all taxa were evaluated for growth habit, growth rate, and summer and winter color. Color descriptions of foliage are provided based on the Royal Horticultural Society colour chart. Exceptional taxa were identified based on needle color, texture, growth habit, and growth rate. Superior green forms include Dirr Seedlings 1 and 2, `Emily', `Rachel', and `Okefenokee'. The superior variegated form is `Webb Gold'. Superior blue forms include `Blue Sport', `Glauca Pendula', and `Twombly Blue', and superior slow-growing forms include `Andelyensis', `Meth Dwarf', `Red Star', and `Heatherbun'. These taxa are recommended to growers, landscapers, and gardeners for production and use.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Localization of immunolabels by electron microscopy and image averaging

1983 ◽  
Vol 41 ◽  
pp. 282-283
Author(s):  
J. Frank ◽  
P.-Y. Sizaret ◽  
A. Verschoor ◽  
J. Lamy
Keyword(s):  
Electron Microscopy ◽  
Single Particle ◽  
Attachment Site ◽  
Uranyl Acetate ◽  
Limulus Polyphemus ◽  
Resolution Limit ◽  
Electron Microscopic ◽  
Image Averaging ◽  
Top View ◽  
Better Than

The accuracy with which the attachment site of immunolabels bound to macromolecules may be localized in electron microscopic images can be considerably improved by using single particle averaging. The example studied in this work showed that the accuracy may be better than the resolution limit imposed by negative staining (∽2nm).The structure used for this demonstration was a halfmolecule of Limulus polyphemus (LP) hemocyanin, consisting of 24 subunits grouped into four hexamers. The top view of this structure was previously studied by image averaging and correspondence analysis. It was found to vary according to the flip or flop position of the molecule, and to the stain imbalance between diagonally opposed hexamers (“rocking effect”). These findings have recently been incorporated into a model of the full 8 × 6 molecule.LP hemocyanin contains eight different polypeptides, and antibodies specific for one, LP II, were used. Uranyl acetate was used as stain. A total of 58 molecule images (29 unlabelled, 29 labelled with antl-LPII Fab) showing the top view were digitized in the microdensitometer with a sampling distance of 50μ corresponding to 6.25nm.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

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