• Applied Biological Chemistry
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• v.41 no.2
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• pp.141-146
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• 1998

In order to determine the optimmum harvest time of Citrus unshiu Marc. var. miyagawa and C. unshiu Marc. var. okitsu produced in Cheju, citrus fruits sampled at packing houses or harvested directly on citrus tree in south and north area of Cheju were analyzed. The fruits were grown in size till middle of October, and soluble solids were increased continuously after that. The fruits size were different by positional directions on the tree, the quality of citrus fruits in central southern positions on the tree was good for fresh fruit consumptions. Compared with only the quality of citrus fruits as a factor of soluble solids, total sugar, pH, and color index, the optimum harvest time were supposed to be reasonable at late of November for C. unshiu Marc. var. okitsu, and at early of December for C. unshiu Marc. var. miyagawa. The results obtained from citrus fruits sampled at packing houses were supposed to be not suitable for determing the optimum harvest time, because of storage after harvest at ordinary harvesting time.

• 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.

• Journal of Korean Traditional Oncology
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• v.16 no.2
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• pp.25-34
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• 2011

Objectives : Citrus is the fruit that is readily available around us. Therefore, we investigated the anti-inflammatory effects of fraction isolated from the Citrus hassaku pericarp in RAW264.7 macrophage cells. Methods : The effects of fraction from Citrus hassaku pericarp on cell viability on RAW264.7 cells were measured by the MTT assay. The mRNA levels of iNOS and COX-2, its protein level by fraction of Citrus hassaku pericarp treatment in RAW264.7 macrophage cells were investigated by RT-PCR and immunoblots. Nitrite accumulation in the culture was measured colorimetrically by the Griess reaction using a Griess reagent. The amount of IL-6 and TNF-${\alpha}$ production was determined using an enzyme-linked immunosorbent assay (ELISA) kit. Results : The results indicated that the fraction of Citrus hassaku pericarp concentration highly suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO) and IL-6 productions without a cytotoxic effect on RAW264.7 cells. fraction of Citrus hassaku pericarp inhibited the expressions of LPS-induced iNOS and COX-2 protein and their mRNA in a dose-dependent manner. Particularly, fraction of Citrus hassaku pericarp suppressed the level of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activity, which was linked with the suppression of LPS-induced phosphorylation of p65 at serine 276 and p65 translocation into nuclei, but not MAPK signaling. In addition, treatment with fraction of Citrus hassaku pericarp inhibited the production of IL-6 and TNF-${\alpha}$ in LPS-stimulated RAW264.7 cells. Conclusion : Our results indicate that fraction of Citrus hassaku pericarp potentially inhibits the biomarkers related to inflammation through the blocking of NF-${\kappa}B$ p65 activation, and it may be a potential therapeutic candidate for the treatment of inflammatory diseases.

• Korean Journal of Organic Agriculture
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• v.28 no.2
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• pp.223-233
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• 2020

The aim of the present study was to investigate the suppressive effects of the bio-sulfur used by eco-friendly farms on the outbreak of citrus scab. To evaluate the inhibiting effect of bio-sulfur on citrus scab germ tube growth, the citrus scab pathogen Elsinoe fawcettiiwas cultured in PDB and agar media, and germ tube growth was observed after bio-sulfur treatment. At both 40 and 88 h after inoculation, germ tube formation was inhibited by 500-, 1000-, and 2000-fold diluted bio-sulfur, and at dilutions above 4000-fold, germ tube formation was observed, although growth was still inhibited, when compared to untreated cultures. Meanwhile, the occurrence of citrus scab on spring-flush leaves in the field was 40.3% in the untreated control and 5.3, 10.3, 12.3, 15.3, and 24.0% when treated with imibenconazole, 2-4 and 6-6 lime-Bordeaux mixtures, which are also used by eco-friendly farms, 500-fold diluted bio-sulfur, lime sulfur, and 1000-fold diluted bio-sulfur, respectively. The occurrence of citrus scab on citrus fruit was 79.3% in the untreated control and 4.0, 33.8, 42.0, 43.3, 44.8, and 78.0% when treated with imibenconazole, 2-4 lime-Bordeaux mixture, 6-6 lime-Bordeaux mixture, 500-fold diluted bio-sulfur, lime sulfur, and 1000-fold diluted bio-sulfur, respectively. Because citrus scab can infect citrus leaves as early as May, as the spring flush begins, preventative control should be implemented by mid- to late-April, thereby increase disease control and reducing both labor and farming costs.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.416-421
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• 1997

Physicochemical properties of six cultivars of Cheju citrus fruits were investigated according to the harvest date. The fruit index of Citrus. unshiu Marc. var. miynawa, C. $natsudaidai{\;}H_{AYATA}$ and C. sudachi ranged from 1.14 to 1.38 with oval form. The fruit index of C. grandis OSEECK, C. aurantiun LINN and C. platymamma. Hort. SWINGLE ranged from 0.89 to 1.03 with a round form. The fruit weight showed the heaviest in C. grandis, followed by C. natsudaidai, C. aurantiun, C. unshiu, C. platymamma and C. sudachi. The rate of flesh showed the highest in C. unshiu, followed by C. platymamma, C. nat녀daidai, C. sudachi, C. grandis and C. aurantiun. The ratio of juice showed the highest in C. unshiu, followed by C. sudachi, C. platymamma., C. natsudaidai,, C. grandis, C. aurantiun. C. unshiu and C. platymamma, which showed a possibility to be used as raw materials for juices. The soluble solid and the Brix/acid ratio of all the varieties increased as the fruits ripen. Especially those of C. unshiu and C. platymamma were high(10.39, 7.67) in full ripe compared to other varieties. Acid content of C. natsudaidai, C. aurantiun, C. grandis and C. sudachi was sustained higher than $3{\sim}5%$ from the middle of September to the middle of January, and there was the possibility of manufacturing aromatic products like citrus vinegar. The C. sudachi contained the highest content of vitamin C,77.48 mg/100 g. The correlation between vitamin C extraction and season was insignificant. Rind and color value of all varieties were investigated, and the value of the L, a and b increased as the fruits were ripen. The value of a of rind of C. $natsudaidai{\;}H_{AYATA}$ and C. grandis until the end of November was negative. This means that their color was not presented by November since the chlorophyll was in the rind, unlike the colors of the rind of C. unshiu, C. sudachi and C. platymamma which were completed by that time.

• Journal of Microbiology and Biotechnology
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• v.19 no.8
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• pp.749-759
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• 2009

A survey of Bacillus thuringiensis (Berliner) strains isolated from Spanish citrus orchards has been performed, and the strains were tested for insecticidal activity against the Mediterranean fruit fly Ceratitis capitata (Wiedemann), a key citrus pest in Spain. From a total of 150 environmental samples, 376 isolates were selected, recording a total B. thuringiensis index of 0.52. The collection was characterized by means of phase-contrast microscopy, SDS-PAGE, and PCR analysis with primer pairs detecting toxin genes cry1, cry2, cry3, cry4, cry5, cry7, cry8, cry9, cry10, cry11, cry12, cry14, cry17, cry19, cry21, cry27, cry39, cry44, cyt1, and cyt2. Diverse crystal inclusion morphologies were identified: bipyramidal (45%), round (40%), adhered to the spore (7%), small (5%), and irregular (3%). SDS-PAGE of spore-crystal preparations revealed 39 different electrophoresis patterns. All primer pairs used in PCR tests gave positive amplifications in strains of our collection, except for primers for detection of cry3, cry19, cry39, or cry44 genes. Strains containing cry1, cry2, cry4, and cry27 genes were the most abundant (48.7%, 46%, 11.2%, and 8.2% of the strains, respectively). Ten different genetic profiles were found, although a total of 109 strains did not amplify with the set of primers used. Screening for toxicity against C. capitata adults was performed using both spore-crystal and soluble fractions. Mortality levels were less than 30%. We have developed a large and diverse B. thuringiensis strain collection with huge potential to control several agricultural pests; however, further research is needed to find out Bt strains active against C. capitata.

• Applied Biological Chemistry
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• v.22 no.1
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• pp.28-32
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• 1979

Experiments were carried out for finding out a reasonable background of inferior processing quality of Korean citrus fruits of unshiu varieties. The results obtained were as follows. 1. It is considered that the essence of fruit tastes were sweetness and acidity. Their contents were $9.0-10.0^{\circ}Bx$ and 5.3-6.6% (as citric acid) respectively. These indicates that Korean native citrus fruits were inferior in quality. 2. The hesperidin contents were 58mg% in early ripe unshiu varieties, but were low comparatively as 45mg% in late varieties. 3. The portions of fruit peel were high as 25% in Im and Sukcheon unshiu. Therefore these varieties are favorable for long-time storage. The juice extraction rate were 50% on the average with not much difference between varieties. 4. Specific gravity of the extracted juice were 1.040. Vit. C and hesperidin contents of the juice were $25{\sim}30mg%$ on the average in all varieties.

• Journal of Life Science
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• v.26 no.12
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• pp.1466-1469
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• 2016

A group of traditional folk medicines obtained from the fruits of Rutaceae plants, such as Ponciri Fructus Immaturus (PFI) from Poncirus trifoliata Raf., Aurantii Fructus Immaturus (AFI) and Aurantii Pericarpium (AP) from Citrus aurantium L., and Aurantii Nobilis Pericarpium (ANP) from Citrus unshiu Marc., has been widely used for improving poor gastrointestinal function in East Asia, including in China and Korea. In the present study, the effects of Rutaceae-fruit-derived folk medicines on gastrointestinal motor function were investigated and compared by measuring in vivo gastric emptying and intestinal transit in mice. Among the aqueous and ethanolic extracts of some Rutaceae-fruit-derived folk medicines, an ethanolic extract of AP (AP-E) significantly accelerated intestinal transit in a dose-dependent manner without affecting gastric emptying. Furthermore, the intestinal transit rate of AP-E was the highest among all extracts examined in this study, including aqueous extracts of PFI, AFI, and ANP, of which the activities of accelerating intestinal transit have been already reported.

• Food Science and Preservation
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• v.19 no.5
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• pp.652-658
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• 2012

This study, the changes in physicochemical properties and hesperidin content of Jeju-processed citrus fruits according to the harvest date were evaluate. The soluble-solid content, pH, and soluble solid-acid ratios gradually increased, but titratable acidity slightly decreased with a delay in the harvest date. The color index, lightness, yellowness, and turbidity slightly decreased whereas the redness slightly increased with a delay in the harvest date. The hesperidin content slightly decreased with a delay in the harvest date. Hesperidin, which is the major cause of juice cloudiness, decreased with a delay in the harvest date. These results suggest that later-harvested fruit juice is bound to be less cloudy.

• Horticultural Science & Technology
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• v.18 no.5
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• pp.599-604
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• 2000

This experimemt was conducted to determine the effect of ridge-up bed with different height (0, 20, 40, 60 cm) on the fruit quality of 'Miyagawa Wase' satsuma mandarin cultivated in a plastic film house. Soil moisture was measured at the soil depths of 10, 30, and 60 cm for each height of ridge-up bed. The time required to reach the condition, -1.4 Mpa at 30 cm deep in soils, which are supposed to be the ideal soil moisture potential and soil depth for high quality satsuma mandarin production, was 100, 60, and 30 days for 20, 40, and 60 cm ridge-up bed, respectively, and more than 100 days for 0 cm. Peel chromaticity by 'a' value was increased as the ridge-up height went up, so that plants grown at the bed with 60 cm height had 11 degree higher value than those of plants grown at the bed with 0 cm height. The 'a/b' values also had a similiar trend as value 'a'. The reducing sugar level of the fruit juice, which was composed of glucose and fructose, was increased as the height of ridge went up, showing significant difference between the ridge heights. The sucrose level had the same trend as the reducing sugar level although the difference between the ridge heights were not significant. Generally, the soluble solid level is considered to be representing the fruit quality. It had 11.4, 12.1, 12.5, $12.8^{\circ}Brix$ for 0, 20, 40, and 60 cm ridge-ups, respectively, showing $1.4^{\circ}Brix$ difference between 0 and 60 cm ridges. Acidity basically showed the same result as that of the soluble solid level depending on the height of the ridges.