• Journal of Life Science
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• v.8 no.6
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• pp.623-626
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• 1998

Conditions for somatic embryogenesis and plant regeneration from stem tissues of Euphorbia pulcherrima were esta-blished. Explants from leaf, petiole, stem were examined for their embryogenesis on MS solid medium supplemented with plant growth hormones in combination at various concentrations. From leaf or petiole explants, callus was indu-ced well but never proceeded to the embryonic stage in our expermental conditions. From stem explants, however, multiple shoots following callus induction emerged in about 6 to 8 weeks on MS agar medium supplemented with 1.5 mg/L of benzyladenine. Upon transfer, roots were developed on hormone-free MS solid medium.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.360-366
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• 2011

Bacterial leaf spot of Euphorbia pulcherrima has been reported in many countries. Characterization by polyphasic approaches indicated that the isolates from India, USA and New Zealand could be distinguished based on rep-PCR profiles and gyrB phylogenies, while the Chinese isolates should be ascribed to Xanthomonas axonopodis pv. poinsettiicola.

• Korean Journal of Plant Taxonomy
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• v.39 no.2
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• pp.114-119
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• 2009

Two naturalized species, Euphorbia dentata Michx. and Securigera varia (L.) Lassen were newly reported from Korea. Euphorbia dentata, "Top-Ni-Dae-Geuk", was found from Jungbu Highway, Daechang-ri, Daechang-myeon, Yeongcheon-si, Gyeongsangbuk-do. It is distinguished from E. pulcherrima by its life form, which is herbaceous, and its upper leaves, which are uniformly green. Securigera varia, "Wang-Gwan-Gal-Kwi-Na-Mul", was found from Hangang, Yeouido, Seoul. The genus Securigera is unrecorded in Korea and distinguished from genus Hedysarum by rose-colored flowers, a peduncle 5-10 cm and by having dense umbels at the tips of the peduncles.

• Journal of Bio-Environment Control
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• v.13 no.2
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• pp.107-111
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• 2004

This study was conducted to examine the possibility of producing poinsettia with various growing media containing used perlite and rockwool slabs as medium components. Pot plants of Euphorbia pulcherrima 'Freedom Red' were grown in 10 media containing used perlite and particles of rockwool slabs at various ratios including 1:1 and 1:3 (v/v). Medium containing used perlite and peatmoss at 1:3 (v/v) was employed as the control treatment. Height, root length, length of the longest branch, number of roots, leaf area, and width and length of the largest bract of plants grown in media containing used perlite were significantly greater than those in the control. Stem diameter and bract count were not affected by the medium composition. From the results, used perlite and rockwool slabs were proved to be a practically useful materials as medium components for pot production of poinsettia plants.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.591-594
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• 2011

A new poinsettia(Euphorbia pulcherrima. Willd. ex Klotzch) cultivar 'Red Stone' was bred by the National Institute of Horticultural and Herbal Science (NIHHS) in 2009. In 2006, a cross was made between 'Freedom Rose', a cultivar with vigorous growth and deep pink bracts, and 'Enduring Pink', a cultivar with pink bracts early colored. 'Red Stone' was finally selected in 2009 after the investigation of the growth and flowering characteristics from 2007 to 2009. 'Red Stone' has red elliptic bracts and strong rugosities between bract veins. Leaf blade is ovate and very dark green. Stem color is reddish and petiole length is medium but relatively longer than that of 'Pepride Red', control cultivar. 'Red Stone' develops as many as 3.8 branches and which is more than double of 'Pepride Red'. Its bracts and transitional leaves are fully colored at 7.5 weeks after short-day commencement. Plant variety protection right of 'Red Stone' was registered in April 2011, and its grant number is 3487.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.220-223
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• 2004

Most plants of commercial poinsettia cultivars grown from cuttings develop mosaic and chlorotic dot symptoms on leaves. Reverse transcription-polymerase chain reaction (RT-PCR) test showed that they were infected with Poinsettia mosaic virus (PnMV). In a survey of commercially grown poinsettias conducted in Korea, PnMV was detected in ten of ten poinsettia cultivars sampled and in 100％ of 178 samples tested. The virus has isometric particles and about 29 nm in diameter. Crystalline virus particles were observed in cytoplasm of cells of diseased plants by transmission electron microscopy. Nucleotide sequence of coat protein gene of PnMV- Kl showed 97.3％ homology with that of a German isolate. This is the first report on PnMV in Korea.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.860-868
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• 2015

The effect of Si supplied during plant cultivation on tolerance to high temperature stress in Euphorbia pulcherrima Willd. 'Ichiban' was investigated. Rooted cuttings were transplanted into 10-cm pots and a complete nutrient solution, containing 0 or $50mg{\cdot}L^{-1}$ Si as either $K_2SiO_3$, $Na_2SiO_3$, or $CaSiO_3$, was supplied through subirrigation or weekly foliar applications. After two months of cultivation, plants were placed in an environment-controlled chamber and subjected to $35{\pm}1^{\circ}C$ (high temperature) conditions for 18 days. Enhanced specific activities of enzymatic antioxidants (APX) and suppressed specific activities of non-enzymatic antioxidants (ELP) were observed in the high temperature-stressed plants with Si application. The Fv/Fm (maximum quantum yield of photosystem II), photosynthetic rate, and Si contents in the shoot increased in the treatments of $K_2SiO_3$ and $Na_2SiO_3$ supplied through subirrigation. The Si-treated plants had more tolerance of high temperature stress than the control plants. Of the Si sources and application methods tested, $K_2SiO_3$ and $Na_2SiO_3$ supplied through subirrigation were found to be the most effective in enhancing tolerance to high temperature stress.

• Applied Microscopy
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• v.36 no.3
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• pp.195-208
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• 2006

Using light and scanning electron microscopy morphological studies of pollens were conducted to determine the sectional boundary and the relationships among eight species of section Zygophyllidium and its five related species of subg. Poinsettia. Pollen characters of 13 species were described, and their diagnostic keys were presented here. Based on the sculpturing patterns and the results of numerical analysis using 10 pollen characters 13 species were divided into four Pollen types: type I, having micro-reticulate shaped pollen (E. hexagona, E. lagunensis, E. hexagonoides and E. bilobata), type II, having reticulate shaped pollen (E. delicatula, E. extipulata, E. dentata, E. heterophylla, E. pulcherrima and E. cyathophora), type III, micro-reticulate shaped pollen with platten muri (E. lacera), and type IV, haying foveolate shaped pollen grains (E. chersonesa and E. eriantha). The results of pollen morphological studies suggest that the sect. Zygophyllidium should be delimited based on only four species, E. hexagona, E. lagunensis, E. hexagonoides and E. bilobata, E. delicatural and E. exstipulata of sect. Zygophyllidium must be transferred to subg. Poinsettia based on pollen morphology. E. eriantha and E. chersonesa having forveolate sculpturing pattern of pollen grains seem to be closely related with species from subg. Agaloma, and additional studies of these species are needed to determine the species relationships within Agaloma group.

• Horticultural Science & Technology
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• v.17 no.5
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• pp.581-583
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• 1999

This experiment was conducted to investigate the effects of uniconazole drench treatment on the growth and flowering of poinsettia and to suggest proper application dosage and time. Plant height, branch length, and leaf area were significantly restricted as the concentration of uniconazole increased. Application doses of 0.05 and 0.10 mg/pot effectively controlled the growth of poinsettia 'V-10 Amy'. Earlier soil drench of uniconazole resulted in more effective reduction in plant height, branch length, and leaf area. In all cases, no noticeable phytotoxicity by plant growth retardants tested was observed.

• Korean journal of applied entomology
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• v.39 no.1
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• pp.5-12
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• 2000

The sweetpotato whiteflies, Bemisia tabaci(Gennadius), were found recently in Korea on Glycine max, Euphorbia pulcherrima, and Rosa hybrida. The biotype identity of Bemisia tabaci in Korea was determined by several DNA markers including the random amplified polymorphic DNAs, and restriction fragments length polymorphism of mitochondrial 12S and 16S rRNA genes. The electromorph profiles of DNA fragments from the rose(Jincheon) and poinsettia(Seoul) populations in Korea are both identical to those of B biotypes distributed in Australia, Israel, and Japan. The populations of B. tabaci collected on Glycine max, Ipomea batatas, and Perilla frutescens in different localities retained the same DNA markes with the population from Lonicera japonica and shikoku of Japan. These populations are non-B biotype and considered as an indigenous type in the Far Eastern Asia Region including Korea and Japan, Morphological Characteristics of B. Tabaci were also observed by the scanning electron microscope and described with the comparison to the other important whitefly pest, Trialeurodes vaporariorum (Westwood).