Article

Quantifying colour and spot characteristics for the ventral petals in Sinningia speciosa

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

This study examined the colour and spot patterns for the ventral petals of a cross line in Sinningia speciosa. The second-generation individuals of the cross line exhibited phenotypic segregation in floral colour and spot patterns. Three colour traits (colour region ratio, region of interest colour, and colour gradient) and five spot traits (spot quantity, spot density, spot area ratio, spot colour, and background colour) were defined and quantified using image processing techniques. The variation in the traits and the correlations between the traits were also investigated. The results indicated a considerable degree of variation among the traits. The proposed approach can quantify petal traits more objectively and precisely compared with conventional naked eye examination. Thus, it can be used for applications, such as new flower variety determination, that require precise trait quantification.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Inthiyaz et al. (2017) identified the petal texture of ten species in the Oxford dataset using local binary patterns (Guo et al., 2010). Hsu et al. (2018) quantified the spot and colour traits of Sinningia speciosa by employing a grey-level co-occurrence matrix (Haralick & Shanmugam, 1973). Yoshioka et al. (2006) analysed the picotee colours of Lisianthus petals and evaluated associations between colours and environmental factors. ...
... The colours, obtained from the scanners and originally in RGB, were converted to CIE L*a*b* colour space, in which L*, a*, and b* represent lightness, redness, and blueness, respectively. The CIE L*a*b* colour parameters were pre-calibrated using a reference board (ColorChecker Passport, X-Rite; Grand Rapids, USA) and multiple regression (Hsu et al., 2018). Thus, the CIE L*a*b* colour parameters were deviceindependent. ...
Article
Plants belonging to genus Sinningia are popular ornamental plants with diverse petal patterns and fascinating petal colours. The patterns and colours of petals are crucial horticultural properties that determine a plant's commercial value. Generally, the patterns and colours of petals are evaluated by experienced horticulturalists. However, manual evaluation can be subjective and the decision criterion could fluctuate due to fatigue. This work proposed a method to automatically quantify the petal patterns and colours by investigating 11 species of Sinningia. The images of the ventral petal of flower specimens were captured using flatbed scanners. The regions of interest (ROI) were defined and segmented from ventral images. Subsequently, a fully convolutional network was applied to the ROI for automatically segmenting variegated parts (i.e., spots, strips, and plaques) from the background. The patterns and colours of petals were then analysed. The proposed method can be used for the automation of petal pattern rating, which generally is performed using naked-eye observations.
... The diversity of these patterns is considered a key morphological characteristic that facilitates the plant-pollinator interaction and angiosperm diversification (Penny, 1983;Endress, 1996;van der Kooi et al., 2019). Several studies have examined variations in nectar guide patterns (Yoshioka et al., 2004;Lootens et al., 2007;Hsu et al., 2018;Hung et al., 2020). In addition to these nectar guide patterns, petal shape and size exhibit considerable diversity. ...
... In image processing analysis, defining the ROI is a frequently used approach to specify the study object in an image. Many studies have applied ROI to quantify petal color patterns among species or varieties (Yoshioka et al., 2004;Lootens et al., 2007;Hsu et al., 2018;Hung et al., 2020). Although these studies have successfully evaluated the variation in nectar guide patterns, ROIs obtained from different petal shapes may not be homologous. ...
Article
Full-text available
Homology is a crucial concept that should be considered while conducting a comparative analysis between organisms. In particular, in the subtribe Ligeriinae, the nectar guide pattern is associated with high diversity in petal shapes and sizes. This largely limits researchers to exclusively examining the interspecific variation in nectar guide patterns on the developmentally homologous region. Thus, to solve this problem, we proposed an approach for defining a homologous region of interest (ROI) that aligns the petal image between specimens based on petal contours and vasculatures. We identified petal contours and vasculatures from the fresh petal image and its histological image through image processing. The homologous ROI was subsequently obtained by applying geometric transformation to the contour and vasculature. The qualification and quantification of nectar guide patterns were subsequently performed based on the homologous ROI. Four patterning modes, namely vascular, random, distal, and proximal, were defined for the qualitative analysis of nectar guide patterns. In the quantitative analysis, principal component (PC) analysis was applied to homologous ROIs, and the PC score of each specimen served as the trait values of nectar guide patterns. The results of the two analyses coincided, and both showed significant associations between nectar guide patterns and pollination types. The proximal mode (corresponding to PC1) and distal mode (corresponding to PC2) together showed the strongest association with pollination types. Species exhibiting the hummingbird and bee pollination types tended to recruit the distal and proximal modes, respectively. Our study conducted a comparative analysis of nectar guide patterns on the developmentally homologous region and provided a comprehensive view of the variation in the nectar guide patterns of Ligeriinae.
... The use of this method recently allowed Lunau et al. (2020) to quantify shine across a large taxonomic sample of flowers, and the same procedure can also easily be applied to access within-population variation. Also, Hsu et al. (2018) used digital photography and sophisticated algorithms for faster digital image processing to quantify petal color gradients and spot patterns in Sinningia speciosa. ...
Article
Full-text available
The evolution of floral traits in animal-pollinated plants involves the interaction between flowers as signal senders and pollinators as signal receivers. Flower colors are very diverse, effect pollinator attraction and flower foraging behavior, and are hypothesized to be shaped through pollinator-mediated selection. However, most of our current understanding of flower color evolution arises from variation between discrete color morphs and completed color shifts accompanying pollinator shifts, while pollinator-mediated selection on continuous variation in flower colors within populations is still scarce. In this review, we summarize experiments quantifying selection on continuous flower color variation in natural plant populations in the context of pollinator interactions. We found that evidence for significant pollinator-mediated selection is surprisingly limited among existing studies. We propose several possible explanations related to the complexity in the interaction between the colors of flowers and the sensory and cognitive abilities of pollinators as well as pollinator behavioral responses, on the one hand, and the distribution of variation in color phenotypes and fitness, on the other hand. We emphasize currently persisting weaknesses in experimental procedures, and provide some suggestions for how to improve methodology. In conclusion, we encourage future research to bring together plant and animal scientists to jointly forward our understanding of the mechanisms and circumstances pollinator-mediated selection on flower color.
Article
Full-text available
This study used three-dimensional (3D) micro-computed tomography (μCT) imaging to examine petal form variation in a hybrid cross of Sinningia speciosa between a cultivar with actinomorphic flowers and a variety with zygomorphic flowers. The major objectives were to determine the genotype–phenotype associations between the petal form variation and CYCLOIDEA2-like alleles in S. speciosa (SsCYC) and to morphologically investigate the differences in petal types between actinomorphic and zygomorphic flowers. In this study, μCT was used to accurately acquire 3D floral images. Landmark-based geometric morphometrics (GM) was applied to evaluate the major form variations of the petals. Nine morphological traits of the petals were defined according to the form variations quantified through the GM analysis. The results indicated that the outward curvature of dorsal petals, the midrib asymmetry of lateral petals, and the dilation of ventral region of the tube were closely associated with the SsCYC genotype. Multiple analyses of form similarity between the petals suggested that the dorsal and ventral petals of actinomorphic plants resembled the ventral petals of zygomorphic plants. This observation indicated that the transition from zygomorphic to actinomorphic flowers in S. speciosa might be caused by the ventralization of the dorsal petals. We demonstrated that the 3D-GM approach can be used to determine genotype–phenotype associations and to provide morphological evidence for the transition of petal types between actinomorphic and zygomorphic flowers in S. speciosa.
Article
Full-text available
Adaptation to pollinators is a key factor of diversification in angiosperms. The Caribbean sister genera Rhytidophyllum and Gesneria present an important diversification of floral characters. Most of their species can be divided in two major pollination syndromes. Large-open flowers with pale colours and great amount of nectar represent the generalist syndrome, while the hummingbird-specialist syndrome corresponds to red tubular flowers with a less important nectar volume. Repeated convergent evolution toward the generalist syndrome in this group suggests that such transitions rely on few genes of moderate to large effect. To test this hypothesis, we built a linkage map and performed a QTL detection for divergent pollination syndrome traits by crossing one specimen of the generalist species Rhytidophyllum auriculatum with one specimen of the hummingbird pollinated R. rupincola. Using geometric morphometrics and univariate traits measurements, we found that floral shape among the second-generation hybrids is correlated with morphological variation observed between generalist and hummingbird-specialist species at the genus level. The QTL analysis showed that colour and nectar volume variation between syndromes involve each one major QTL while floral shape has a more complex genetic basis and rely on few genes of moderate effect. Finally, we did not detect any genetic linkage between the QTLs underlying those traits. This genetic independence of traits could have facilitated evolution toward optimal syndromes.
Article
Full-text available
Petal shape and picotee colour pattern of lisianthus [Eustoma grandiflorum (Raf.) Shinn.] were qualitatively evaluated by means of personal computer-based methods. In lisianthus, many cultivars have been improved to obtain various floral characteristics. Picotee color patterns and flower shape are commercially important in this species and the availability of an objective and quantitative evaluation method is of vital importance for investigations related to the genetic and physiological aspects of these characteristics. Our objectives were to evaluate petal shape variation quantitatively and to establish a new quantitative evaluation method for picotee color patterns. We succeeded in quantitatively evaluating petal shape variation by means of elliptic Fourier descriptors and principal-components analysis, and in evaluating picotee color patterns by a newly developed procedure based on comparative marginal distribution. Petal shape variation was divided into symmetrical and asymmetrical elements of the entire shape variation. Both groups were additionally divided into several components. The variations in picotee color pattern were effectively described by the first through fourth principal components. Comparing the varietal effect of these components, nested analyses of variance showed that the differences between cultivars in picotee color pattern were smaller than those of the symmetrical shape elements. In addition, the environmental effects on picotee color formation were greater than those of symmetrical shape formation. The evaluation methods described in this study are effective for further investigations, and are applicable to other floricultural crops as well as lisianthus.
Article
Full-text available
In azalea breeding, flower colour is the most essential selection criterion, but leaf morphology also influences attractiveness of the plant. Despite extensive study of the inheritance of flower colour, no explanation has yet been found for the pink phenotype. We have used image analysis to quantify flower colour and leaf morphology. Flower colour was quantified in a whole population. Pink flower colour has been confirmed to be the result of a gene-dosage effect; two major QTLs were found for flower colour as well as some minor QTLs that seem to be related to pink coloration. Leaf morphology (colour and shape) was scored in four unrelated populations by means of image analysis. The image analysis generated continuous, highly informative data for QTL mapping. Both classical parameters and symmetrical elliptic Fourier descriptors successfully described leaf morphology. Image analysis resulted in large data sets that had to be combined in principal components. Only a limited number of QTLs were found for leaf colour, but we could discern some major QTLs for leaf shape and size that were consistent over the different mapping populations. These QTLs are the most interesting candidates for future analysis of the selected traits. The multi-population approach certainly proved to be valuable for QTL mapping of complex traits. For leaf morphology, however, more research is needed to identify the most valuable QTLs for future use in MAS.
Article
Full-text available
The accord between symmetries of flower shape (external contours) and nectar guides (internal contours) was examined using the bulbous flora of South Africa, and in the general floras of Britain, Alpine Colorado, Canadian Arctic and Israel. It was found that radially symmetrical flowers have radially symmetrical nectar guides whereas bilaterally symmetrical flowers have bilaterally symmetrical nectar guides. It is suggested that the complementarity between the external and the internal contours of the flower increases the probability that, and efficiency with which, a bee moves into the flower's centre and towards the sporophylls and access to floral rewards, regardless of the flower's form and the bee's previous experience. Patterns of coloration of tepals against background and nectar guides against tepals also accord with behavioural and sensory characteristics of pollinators. It is suggested that the complementarity of contours is probably constrained by floral development, but patterns of coloration of tepals against background and nectar guides against tepals is constrained by pollinators' sensory physiology.
Article
Full-text available
Nectar guides, contrasting patterns on flowers that supposedly direct pollinators towards a concealed nectar reward, are taxonomically widespread. However, there have been few studies of their functional significance and effects on plant fitness. Most previous studies focused on pollinator behaviour and used artificial flowers in laboratory settings. We experimentally investigated the role of putative nectar guides in a natural system: the South African iris Lapeirousia oreogena, whose flowers have a clearly visible pattern of six white arrow-markings pointing towards the narrow entrance of the long corolla tube, and its sole pollinator, a long-proboscid nemestrinid fly. We painted over none, some or all of the white arrow-markings with ink that matched the colour of the corolla background. Although arrow-marking removal had little effect on the approaches by flies to flowers from a distance, it dramatically reduced the likelihood of proboscis insertion. Export of pollen dye analogue (an estimate of male fitness) was reduced to almost zero in flowers from which all nectar guides had been removed, and fruit set (a measure of female fitness) was also significantly reduced. Our results confirm that the markings on L. oreogena flowers serve as nectar guides and suggest that they are under strong selective maintenance through both male and female fitness components in this pollination system.
Article
Full-text available
A crucial stage in the interaction between pollinators and plants is the moment of physical contact between them, known as flower inspection, or handling. Floral guides - conspicuous colour markings, or structural features of flower corollas - have been shown to be important in the inspecting behaviour of many insects, particularly in diurnal species. For the nocturnal hawkmoth Manduca sexta tactile input has an important role in flower inspection, but there is no knowledge about the use of visual floral guides in this behaviour. I carried out a series of experiments to first, evaluate the putative role of floral guides during flower inspection and second, to explore how simultaneous tactile and visual guides could influence this behaviour. Results show that visual floral guides affect flower inspection by M. sexta. Moths confine proboscis placement to areas of higher light reflectance regardless of their chromaticity, but do not appear to show movements in any particular direction within these areas. I also recorded inspection times, finding that moths can learn to inspect flowers more efficiently when visual floral guides are available. Additionally, I found that some visual floral guides can affect the body orientation that moths adopt while hovering in front of horizontal models. Finally, when presented with flower models offering both visual and tactile guides, the former influenced proboscis placement, whereas the latter controlled proboscis movements. Results show that innate inspection behaviour is under multimodal sensory control, consistent with other components of the foraging task. Fine scale inspection movements (elicited by diverse floral traits) and the tight adjustment between the morphology of pollinators and flowers appear to be adaptively integrated, facilitating reward assessment and effective pollen transfer.
Article
Full-text available
The diurnal hawkmoth Macroglossum stellatarum is known to feed from a variety of flower species of almost all colours, forms and sizes. A newly eclosed imago, however, has to find its first flower by means of an innate flower template. This study investigates which visual flower features are represented in this template and their relative importance. Newly eclosed imagines were tested for their innate preferences, using artificial flowers made out of coloured paper or projected onto a screen through interference filters. The moths were found to have a strong preference for 440 nm and a weaker preference for 540 nm. The attractiveness of a colour increases with light intensity. The background colour, as well as the spectral composition of the ambient illumination, influences the choice behaviour. Blue paper disks against a yellowish background are chosen much more often than the same disks against a bluish background. Similarly, under ultraviolet-rich illumination, the preference for 540 nm is much more pronounced than under yellowish illumination. Disks of approximately 32 mm in diameter are preferred to smaller and larger ones, and a sectored pattern is more attractive than a ring pattern. Pattern preferences are less pronounced with coloured than with black-and-white patterns. Tests using combinations of two parameters reveal that size is more important than colour and that colour is more important than pattern.
Article
Full-text available
The use of mathematical morphology in the L*a*b* colour space is discussed. Initially, a description of the characteristics of the L*a*b* space and a comparison to the HLS space are given. This is followed by a theoretical demonstration of the use of weighting functions to impose a complete order on a vector space. Various colour weighting functions are considered, and one based on a model of an electrostatic potential is chosen for further development. A lexicographical order using this weighting function allows one to simulate a complete order by colour saturation, a notion absent from the definition of the L*a*b* space. Demonstrations of the basic morphological operators and of the top-hat operator making use of the proposed colour order are shown.
Article
Contrasting flower color patterns that putatively attract or direct pollinators towards a reward are common among angiosperms. In the deceptive orchid Anacamptis morio, the lower petal, which makes up most of the floral display, has a light central patch with dark markings. Within populations, there is pronounced variation in petal brightness, patch size, amount of dark markings, and contrast between patch and petal margin. We tested whether pollinators mediate selection on these color traits and on morphology (plant height, number of flowers, corolla size, spur length), and whether selection is consistent with facilitated or negative frequency-dependent pollination. Pollinators mediated strong selection for increased petal brightness (Δβpoll = 0.42) and contrast (Δβpoll = 0.51). Pollinators also tended to mediate stabilizing selection on brightness (Δγpoll = -0.27, n.s.) favoring the most common phenotype in the population. Selection for reduced petal brightness among hand-pollinated plants indicated a fitness cost associated with brightness. The results demonstrate that flower color traits influence pollination success and seed production in A. morio, indicating that they affect attractiveness to pollinators, efficiency of pollen transfer, or both. The documented selection is consistent with facilitated pollination and selection for color convergence towards co-occurring rewarding species. This article is protected by copyright. All rights reserved.
Article
Potential consumers were surveyed in the spring of 1996 to gain insight into preferences for flower and leaf color in New Guinea impatiens (Impatiens hawkeri Bull.). Survey participants indicated a preference for bright solid colors, and bicolor flowers. The most preferred solid flower colors were red-violet, and red. The least preferred solid flower colors were pink and blush. Potential consumers ranked bicolor flowers over their solid color counterparts. Red and variegated foliage were preferred to solid green. Foliage with solid red upper or lower surfaces were preferred 2:1 over variegated foliage.
Article
RNA interference (RNAi) is an efficient and powerful technique for gene silencing compared with antisense and sense suppression. Here we report adaptation of RNAi technology to modify flower colors in gentian, targeted for suppression of three anthocyanin biosynthetic genes; chalcone synthase (CHS), anthocyanidin synthase (ANS) and flavonoid 3′,5′-hydroxylase (F3′5′H). The petals of transgenic gentian plants with a suppressed CHS gene exhibited pure white to pale-blue color, while those with a suppressed ANS gene showed only pale-blue. The suppression of the F3′5′H gene decreased delphinidin derivatives and increased cyanidin derivatives, and led to magenta flower colors. Northern blot analyses confirmed that all transgenic gentian plants showing typical phenotypes had strongly suppressed transcriptions of the targeted genes, corresponding with a change in anthocyanin accumulation and composition in their petals. Some rolCpro-CHSir transgenic gentians exhibited bicolor phenotypes with reduced anthocyanin accumulation along the vascular bundles. These data demonstrated that the suppression of anthocyanin biosynthetic genes by RNAi was successfully applied to gentian plants to change flower color, and this could be useful for designing novel flower color and patterns. Transgenic gentian plants produced in this study might be utilized as elite materials in the breeding of gentian plants in the near future.
Article
Although interspecific competition for pollination is hypothesized to result in divergence in floral traits (i.e., character displacement), few studies have tested whether selection on these traits differs in the presence and absence of a competitor for pollination. We measured phenotypic selection on floral traits of Lobelia siphilitica L. growing in the presence and absence of Mimulus ringens L., a potential competitor for pollination. Because L. siphilitica is gynodioecious, we estimated selection separately for female and hermaphrodite plants. The presence of M. ringens did not decrease seed set of L. siphilitica. However, the presence of M. ringens did affect selection on daily display size of female L. siphilitica; there was significant selection for smaller daily displays in the absence of M. ringens, but nonsignificant selection for larger displays in the presence of M. ringens. In addition, selection on flower colour did not differ in the presence and absence of M. ringens, but did differ between female and hermaphrodite L. siphilitica. Consequently, our results suggest that the evolution of floral traits in L. siphilitica, but not the evolution of sexual dimorphism in these traits, can be affected by interactions for pollination with M. ringens.
Article
Glycosides of the 6 common anthocyanidins all formed co-pigment complexes with flavonoids and other compounds at pH's ranging from 2 to 5. The formation of co-pigment complexes resulted in a bathochromic shift in the visible λmax of the anthocyanins and a large increase in extinction at pH 3 and higher. These complexes apparently formed with both the red flavylium salts and the purple anhydro bases. The increase in extinction at pH's 3 to 5 was attributed to the stabilizing effect co-pigmentation had on the anhydro bases. The degree of co-pigmentation was a function of the concentration of the anthocyanins and the molar ratio of co-pigments to anthocyanins. Co-pigmentation offers an explanation for the infinite color variations that occur in flowers in a pH range where anthocyanins alone are virtually colorless.
Article
In 1913 Willstätter made the striking observation that the same pigment can give rise to different colors. Thus, the same pigment, cyanin, is found in the blue cornflower and in the red rose. Willstätter attributed the variety of flower colors to different pH values in solution. Indeed, anthocyanin changes its color with pH; it appears red in acidic, violet in neutral, and blue in basic aqueous solution. Willstätter's pH-theory for explaining flower color variation is still to be found in major text books of organic chemistry. Very recently, however, reinvestigation has disclosed that the color variation and stabilization of anthocyanins in aqueous solution could have other causes, namely self-association, copigmentation and intramolecular sandwich-type stacking. The stacking would be mainly brought about by intermolecular or intramolecular hydrophobic interaction between aromatic nuclei such as anthocyanidins, flavones and aromatic acids. In addition, hydrogen bonds and charge transfer interactions may also be involved. The most interesting molecular complexes of anthocyanins are the metalloanthocyanins such as commelinin and protocyanin (blue cornflower pigment). These seemingly pure blue complexes each consist of six anthocyanin and six flavone molecules and two metal ions; their molecular weight is nearly 10000. A structure is proposed for commelinin.
Article
Mimulus luteus (Scrophulariaceae) is a perennial herb occurring in the South American Andes that shows a wide variation in the size and shape of a red spot on the lower lobe of the yellow flower. We describe the preference of four insects (three bees and one butterfly) and one hummingbird species for floral characters, and estimated the strength, direction, and form of pollinator-mediated selection through female fitness. We applied geometric morphometrics to describe the preference of pollinator species for different guide shapes. Our results revealed striking differences in the floral phenotypes preferred by insects and hummingbirds. Insects visited flowers with corollas 1.25-fold larger and guides 1.72-fold larger than the hummingbird species did. While insects preferred flowers with nectar guides pointing toward the corolla tube, the hummingbird preferred flowers with heart-shaped nectar guides. Most of the floral preferences shown by pollinators translated into significant linear and nonlinear selection coefficients. When selection was analyzed on a per-flower basis and for female fitness, corolla size was under positive directional selection, and nectar guide size and shape were under disruptive selection. Because the insect and hummingbird pollinators showed a strong segregation in their daily activity time, we suggest that current disruptive selection on the nectar guide phenotype can result from the differ-ential availability of the rewarding floral variants over a day. Our findings suggest that pollinator-mediated selection favoring extreme phenotypes in M. luteus may not only con-tribute to high nectar guide variation found in this species, but also can promote divergence of corolla and nectar guide traits.
Previous investigations indicate that edge information, gray level histogram information, texture information, and shape information are all useful in detecting objects. Gray level cooccurrence matrices contain a form of each of these types of information. Hence applying measures defined on cooccurrence matrices to the object detection problem would seem to be an approach which should be investigated. This paper presents a formulation of such an approach. The decision logic employed assumes that measures computed from regions containing the object form a cluster defined by N (μ0, Σ0) in measurement space, while measures computed from regions not containing the object lie some distance away from this cluster. To help assure that this is the case, a measurement selection algorithm was formulated. Studies are reported which show testing detection accuracies of better than 90% on a number of experiments.
Article
An improved and general approach to connected-component labeling of images is presented. The algorithm presented in this paper processes images in predetermined order, which means that the processing order depends only on the image representation scheme and not on specific properties of the image. The algorithm handles a wide variety of image representation schemes (rasters, run lengths, quadrees, bintrees, etc.). How to adapt the standard UNION-FIND algorithm to permit reuse of temporary labels is shown. This is done using a technique called age balancing, in which, when two labels are merged, the older label becomes the father of the younger label. This technique can be made to coexist with the more conventional rule of weight balancing, in which the label with more descendants becomes the father of the label with fewer descendants. Various image scanning orders are examined and classified. It is also shown that when the algorithm is specialized to a pixel array scanned in raster order, the total processing time is linear in the number of pixels. The linear-time processing time follows from a special property of the UNION-FIND algorithm, which may be of independent interest. This property states that under certain restrictions on the input, UNION-FIND runs in time linear in the number of FIND and UNION operations. Under these restrictions, linear-time performance can be achieved without resorting to the more complicated Gabow-Tarjan algorithm for disjoint set union.
Color vision: Perspectives from different disciplines
  • W G Backhaus
  • R Kliegl
  • J S Werner
Backhaus, W. G., Kliegl, R., & Werner, J. S. (1998). Color vision: Perspectives from different disciplines. Walter de Gruyter.
Textural features in flower classification
  • D Guru
  • Y S Kumar
  • S Manjunath
Guru, D., Kumar, Y. S., & Manjunath, S. (2011). Textural features in flower classification. Mathematical and Computer Modelling, 54(3), 1030e1036.
Paper presented at the XXVII International Horticultural Congress-IHC2006: II International Symposium on Plant Genetic Resources of Horticultural. Flower color and florescence mutants obtained using electron beam irradiation of chrysanthemum buds
  • M Sun
  • P Li
  • Q.-X Zhang
Sun, M., Li, P., & Zhang, Q.-X. (2006). Paper presented at the XXVII International Horticultural Congress-IHC2006: II International Symposium on Plant Genetic Resources of Horticultural. Flower color and florescence mutants obtained using electron beam irradiation of chrysanthemum buds (Vol. 760).
Chen at the Dr. Cecilia Koo Botanic Conservation and Environmental Protection Centre for providing the F 1 S. speciosa plants. We thank Dr. Der-Ming Yeh at National
  • Chun-Ming
Chun-Ming Chen at the Dr. Cecilia Koo Botanic Conservation and Environmental Protection Centre for providing the F 1 S. speciosa plants. We thank Dr. Der-Ming Yeh at National
TG/1/3. General introduction to the examination of distinctness, uniformity and stability and the development of harmonized descriptions of new varieties of plants
  • M M Trivedi
  • C A Harlow
  • R W Conners
  • S Goh
Trivedi, M. M., Harlow, C. A., Conners, R. W., & Goh, S. (1984). Object detection based on grey level cooccurrence. Computer Vision, Graphics, and Image Processing, 28(2), 199e219. UPOV. (2002). TG/1/3. General introduction to the examination of distinctness, uniformity and stability and the development of harmonized descriptions of new varieties of plants. Geneva: Switzerland.