• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.211-214
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• 1994

Paulowina witches'-broom mycoplasma-like organism (PWB-MLO) was transmitted experimentally to periwinkle (Catharanthus roseus L.) plant by tobacco leaf bug (Cyrtopeltis tenuis Reuter). Adults of the leaf bugs were allowed to feed on the witch's-broom infected paulownia (Paulownia tomentoas Steud.) trees for three weeks to insure the acquisition of PWB-MLO and then transferred to healthy seedlings of periwinkle and paulownia plants. In 25∼35 days after transfer of the viruliferous leaf bugs, six out of the ten periwinkle plants showed‘little-leaf’symptoms, while the paulowina seedlings remained symptomless. Presence of MLO in the infected periwinkle tissue was diagnosed by fluorescence microscopy and MLO particles were observed under electron microscope, confirming the transmission of PWB-MLO to periwinkle.

• Journal of Microbiology
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• v.45 no.5
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• pp.388-393
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• 2007

Citrus variegated chlorosis (CVC) is a disease of the sweet orange [Citrus sinensis (L.)], which is caused by Xylella fastidiosa subsp. pauca, a phytopathogenic bacterium that has been shown to infect all sweet orange cultivars. Sweet orange trees have been occasionally observed to be infected by Xylella fastidiosa without evidencing severe disease symptoms, whereas other trees in the same grove may exhibit severe disease symptoms. The principal endophytic bacterial species isolated from such CVC-asymptomatic citrus plants is Curtobacterium flaccumfaciens. The Madagascar periwinkle [Citrus sinensis (L.)] is a model plant which has been used to study X. fastidiosa in greenhouse environments. In order to characterize the interactions of X. fastidiosa and C. flaccumfaciens, periwinkle plants were inoculated separately with C. flaccumfaciens, X. fastidiosa, and both bacteria together. The number of flowers produced by the plants, the heights of the plants, and the exhibited disease symptoms were evaluated. PCR-primers for C. flaccumfaciens were designed in order to verify the presence of this endophytic bacterium in plant tissue, and to complement an existing assay for X. fastidiosa. These primers were capable of detecting C. flaccumfaciens in the periwinkle in the presence of X. fastidiosa. X. fastidiosa induced stunting and reduced the number of flowers produced by the periwinkle. When C. flaccumfaciens was inoculated together with X. fastidiosa, no stunting was observed. The number of flowers produced by our doubly- inoculated plants was an intermediate between the number produced by the plants inoculated with either of the bacteria separately. Our data indicate that C. flaccumfaciens interacted with X. fastidiosa in C. roseus, and reduced the severity of the disease symptoms induced by X. fastidiosa. Periwinkle is considered to be an excellent experimental system by which the interaction of C. flaccumfaciens and other endophytic bacteria with X. fastidiosa can be studied.

• The Plant Pathology Journal
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• v.28 no.2
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• pp.191-196
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• 2012

Periwinkle seedlings (Cantharanthus roseus) were inoculated with jujube witches'- broom (JWB) phytoplasma via grafting to analyze the migration of JWB phytoplasmas within the host plant. The phytoplasmas were detected using nested polymerase chain reaction (PCR) and fluorescence microscopy. Fluorescence microscopy was a simple and easy method of detecting phytoplasmas; however, it was not sufficiently sensitive to detect very low phytoplasma concentrations. Therefore, the migration of JWB phytoplasma was investigated through PCR. The first migration of JWB phytoplasma from an infected tissue to healthy tissues occurred late. After grafting, the phytoplasmas moved from the inoculated twig (or scion) to the main stem, which took 28 days. Afterward, the phytoplasma migrated faster and took less than 4 days to spread into the roots from the main stem. All twigs were then successively colonized by the JWB phytoplasmas from the bottom to the top. JWB phytoplasma was detected via nested PCR in all parts of the periwinkle seedling 82 days after inoculation. Based on these results, the inoculated JWB phytoplasma appeared to migrate downward to the roots along the main stem during the early stages, and then continued to move upward, colonizing twigs along the way until they reached the apex.

• Animal Systematics, Evolution and Diversity
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• v.32 no.2
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• pp.105-111
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• 2016

The genetic structure of marine animals that inhabit the seashore is affected by numerous factors. Of these, gene flow and natural selection during recruitment have strong influences on the genetic structure of seashore-dwelling species that have larval periods. Relative contributions of these two factors to the genetic structure of marine species would be determined mainly by the duration of larval stage. The relationship between larval period and genetic structure of population has been rarely studied in Korea. In this study, genetic variations of cytochrome oxidase subunit I (COI) were analyzed in two dominant species on rocky shore habitats in the Korean peninsula: periwinkle Littorina brevicula and acorn barnacle Fistulobalanus albicostatus. Both species are not strongly structured and may have experienced recent population expansion. Unlike periwinkle, however, barnacle populations have considerable genetic variation, and show a bimodal pattern of mismatch distribution. These results suggest that barnacle populations are more affected by local adaptation rather than gene flow via larval migration. The bimodal patterns of barnacle populations observed in mismatch distribution plots imply that they may have experienced secondary contact. Further studies on seashore-dwelling species are expected to be useful in understanding the evolution of the coastal ecosystem around Korean waters.

• Journal of Korean Society of Forest Science
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• v.83 no.1
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• pp.1-5
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• 1994

Sixteen kinds of piercing-sucking mouth type insects were observed at witches'-broom diseased paulownia (Paulownia tomentosa) trees. Among ten insect species tested, a leafhopper, Empoasca sp., transmitted paulownia witches'-broom mycoplasma-like organism(PWB-MLO) to periwinkle(Catharanthus roseus) plant. Adults of this leafhopper were collected from PWB-diseased paulownia trees. The leafhpoppers were allowed to feed on the PWB-infected paulownia trees for three weeks to acquire PWB-MLO. These insects were then transferred to healthy seedlings of paulownia and periwinkle plants for inoculation-feeding. About 30-40days after the inoculation, "little-leaf" symptoms developed on periwinkle plants, but no symptoms developed on paulownia seedlings. MLO infection in the diseased periwinkle tissue was diagnosed by fluorescence microscopy. MLOs were observed in the sieve tubes by electron microscopy, proving the insect transmission of PWB-MLO.

• Korean Journal Plant Pathology
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• v.1 no.3
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• pp.184-189
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• 1985

Transmission of mulberry dwarf mycoplasma (MDM) from diseased mulberry to 5 herbaceous plants (periwinkle, white clover, Ladino clover, red clover, and Chinese milk vetch) through insect vector, Hishimonus sellatus, was confirmed by symptom expression and microscopic evidences. The earliest symptom appearance was noticed on periwinkle in which incubation period was 25-30 days, while it ranged 35-40 days in the other plant species. The common symptoms of MDM infected plants were characterized by poor plant growth with accompanying discolorations of leaves (chlorosis with vein clearing in periwinkle, reddish in red clover, brownish in white and Ladino clovers, and yellowish in Chinese milk vetch). Mycoplasmal infections were diagnosed light microscopically by Dienes' and toluidine blue staining of hand-cut and Epon-embedded sections, respectively. In Dienes' stain, all the plants infected with MDM showed specific staining reaction in phloems. In toluidine blue stain, mycoplasmal existence was noted by granular appearance in sieve tubes which were confirmed to be mycoplasma-like organisms under an electron microscope.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.635-639
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• 2012

The present study was initiated to find out the insect vector of mulberry dwarf phytoplasma. Among the collected insects from mulberry cultivation region, the sucking insects (Hishimonas sellatus, Bothrogonia japonica and Balclutha punctata) were selected for transmission of mulberry dwarf phytoplasma. Sucking insects, H. sellatus and B. punctata successfully transmitted phytoplasma to healthy seedling mulberry and periwinkle plants by inoculation-feeding. Typical dwarf symptom was observed in mulberry tree, but very slender twigs on stem and formatted small leaves were found on periwinkle plants, which are typical witches' broom symptoms. The phytoplasmas were detected in all samples exception sucking insects B. japonica using phytoplasma universal primer pair R16F2n/R2.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.215-220
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• 1984

Mulberry dwarf, paulownia witches' broom, jujube witches' broom, and sumach witches' broom are known to be associated with mycoplamalike organisms(MLO) in Korea. Simple microscopic detection of MLO infection in these plants was attempted. Periwinkle plant was also tested. Application of $0.2\%\;and\;0.4\%$ solution of Dienes' stain gave diagnoatic value for MLO-induced diseases of periwinkle and mulberry. Among the various plant parts examined, young herbaceous stem just below the apical part gave the best result. Density of staining reaction was proportional to disease severity. Longitudial sections were superior to transverse sections in confirming MLO infection by staining. Light source without blue filter was useful for increasing the color contrast between sieve tube and xylem vessel and for eliminating misinterpretation. Paulownia, jujube, and sumach samples gave no clear difference in staining reaction between healthy and diseased sections even when various modifications of Dienes' staining procedure were tried.

• Advances in nano research
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• v.15 no.1
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• pp.35-48
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• 2023

Nanoparticles are known for their outstanding properties such as particle size, surface area, optical and electrical properties. These properties have significantly boasted their applications in various surface phenomena. In this work, calcium oxide nanoparticles were synthesized from periwinkle shells as an approach towards waste management through resource recovery. The sol gel method was used for the synthesis. The nanoparticles were characterized using X-Ray diffractometer (XRD), Fourier Transformed Infra-Red Spectrophotometer (FTIR), Brunauer Emmett Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultra violet visible spectrophotometer (UV-visible). While DLS and SEM underestimate the particle diameter, the BET analysis reveals surface area of 138.998 m²/g, pore volume = 0.167 m³/g and pore diameter of 2.47 nm. The nanoparticles were also employed as an adsorbent for the purification of dye (methyl orange) contaminated water. The adsorbent showed excellent removal efficiency (up to 97 %) for the dye through the mechanism of physical adsorption. The adsorption of the dye fitted the Langmuir and Temkin models. Analysis of FTIR spectrum after adsorption complemented with computational chemistry modelling to reveal the imine nitrogen group as the site for the adsorption of the dye unto the nanomaterials. The synthesized nanomaterials have an average particle size of 24 nm, showed a unique XRD peak and is thermally and mechanically stable within the investigated temperature range (30 to 70 ℃).

• Korean Journal of Agricultural Science
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• v.17 no.1
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• pp.9-17
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• 1990

Erwinia carotovora subsp. carotovora, Pseudomonas viridiflava and Pseudomonas marginalis pv. marginalis were tested for their pathogenicity to 35 kinds of domestic flowering plants. Among them, the following domestic flowering plants showed clear symptoms. 1. Erwinia carotovora subsp. carotovora : (Needle inoculation). Carnation(Dianthus catgophylius L.), madagascar periwinkle(Vinca rosea L.), flower gentle(Amaranthus tricolor L.), snapdragon(Antirrhinum majus L.), chrysanthemum(Chrysanthemum morifolium Ram.), mexiacan ageratum(Ageratum houstonianum Mill), china aster(Callistephus chinensis), youth and old age(Zinnia elegans Jacq.), common nasturtium(Tropaeorum majus L.), scarlet sage(Salvia splendens F.), dahlia(Dahia hybrida), pot marigold(Calendula officinalis L.), begonia treevine(Cissus dicolor Blume), cosmos(Cosmos bipinnatus Cav.), globe amaranth(Gomphrena globosa L.), black eyed susan(Thumbergia alata Bojer), common gypsophila(Gypsophila elegans Bieb.), ghent gladiolus(Gladiolus gandavensis Van.), indian shot(Canna orchiodes Bailey), iris(Iris nertschinskia Lodd), cyclamen primula(Dodecatheon meadia L.), scarlet kafir lily(Clivia miniata Regel.), flowering cabbage(Brassica oleracea L.). (Spray inoculation). Carnation, madagascar periwinkle, flower gentle, snapdragon, common nasturtium, ghent gladiolus, indian shot, cyclamen primula. 2. Pseudomonas viridiflava : (Needle inoculation). Carnation, madagascar periwinkle, snapdragon, chrysanthemum, cockscomb, mexican ageratum, china aster, common nasturtium, common petunia(Petunia hybrida Vilm), pot marigold, begonia treevine, cosmos, black eyed susan, common gypsophila, ghent gladiolus, indian shot, cyclamen primula, scarlet kafir-lily, flowering cabbage. (Spray inoculation). Common nasturtium, ghent gladiolus, indian shot, cyclamen primula. 3. Pseudomonas marginalis pv. marginalis : (Needle inoculation). Carnation, madagascar periwinkle, flower gentle, snapdragon, cockscomb, mexican ageratum, youth and old age, common nasturitium, common petunia, sweet william(Dianthus barbatus L.), pot marigold, begonia treevine, cosmos, common gypsophila, ghent gladiolus, indian shot, iris, cyclamen primula, scarlet kafir-Lily, flowering cabbage. (Spray inoculation). Common nasturtium, ghent gladiolus, indian shot, cyclamen primula.