• Mycobiology
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• v.28 no.3
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• pp.158-162
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• 2000

Twenty-three isolates of Fusarium spp. were obtained from decayed citrus fruits in the fields and storages in 1998-1999. Of them, six and five isolates belonged to F. proliferatum and F. moniliforme, respectively, which were the most common. F. solani and F. sambucinum had each two isolates, F. equiseti had one isolate and seven isolates were unidentified. They produced symptoms of two types in pathogenicity test: those with leathery, beige to light or dark brown, and sunken lesions without surface mycelium (type-1) and those with lesions covered with white, beige or pink surface mycelium (type-2). Four of six isolates identified to F. proliferatum and two unidentified isolates produced type-1 lesions, and all isolates identified to F. moniliforme, F. solani, F. sambucinum, F. equiseti and five unidentified isolates produced type-2 lesions.

• Culinary science and hospitality research
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• v.9 no.4
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• pp.69-80
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• 2003

To develope natural food preservatives antimicrobial effect of the natural products against food-related bacteria and yeast The purpose of this study was evaluate antimicrobial effect of the citrus seeds. antimicrobial activities of methanol extracts from the citrus seeds investigate against Escherichia coli O26, Staphylococcus aureus 6358, Saccharomyces cerevisiae IBM 4274, Bacillus licheuiformis 9945a and Alcoligenes faecalis. Citrus seeds is containing to moisture 4∼6.5%, curd protein 11∼15%, curd lipid 32∼46%, curd carbohydrate 22∼45 % and ash 2∼4 %, that is containing to flavornoid 12∼48mg% and phenolic compound 22∼53mg%. Solidity content of the methanol extract from the citrus seeds was 0.8∼1.2%. Almost all of the methanol extracts from citrus seeds exhibited growth inhibiting activities for most of microorganisms tested. The methanol extracts from Citrus grandis, C. sunki, C. sulcata showed the growth inhibitory effects against Escherichia coli O26. The methanol extracts from C. obovoidea, C. sulcata, C. aurantium showed the growth inhibitory effects against Staphylococcus aureus 6358. The methanol extracts from C. obovoidea, C. sulcata, C. tangerina showed the growth inhibitory effects against Saccharomyces cerevisiae IBM 4274. The methanol extracts from C. obovoidea, C sunki, C. sulcata, C. tangerinan, C. natsudaidai, C. iyo, C. aurantium showed the growth inhibitory effects against Bacillus licheuiformis 9945a. The methanol extracts from C. obovoidea, C sunki, C. sulcata, C. aurantium showed the growth inhibitory effects against Alcoligenes faecalis. Among this especially, Showed growth inhibiting activity of the methanol extracts from Citrus sulcata that about microorganisms investigated. If apply searching suitable application method about such the citrus seeds antimicrobial activity, role as good antimicorbial material in storage or cooking of food, processing is expected.

• Applied Biological Chemistry
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• v.23 no.3
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• pp.178-183
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• 1980

Citrus fruits harvested in 1979 were collected from markets scattered in Jeju and Seogwipo area on Jeju island and also from citrus orchards with five, ten, fifteen, twenty, and thirty years of cultivation history. Organophorous insecticides and organochloro acaricides in the pulp of fruits were analysed by gas liquid chromatograph. It was found that EPN and Kelthane were most significant residues found in the citrus fruits in terms of both level and frequency of occurrence. Among citrus fruits collected from various markets, EPN was detected in 28% of the fruits samples in the range of 0.009 to 0.025 ppm, while Kelthane, at lower level, was found in all citrus fruits in the range of trace to 0.007 ppm. Residue levels of citrus fruits from orchards of various cultivated periods, in general, confirmed those of the fruits collected from commercial markets. However, residues of Kelthane in the citrus fruits tended to increase with orchards having longer cultivation history.

• The Plant Pathology Journal
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• v.15 no.6
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• pp.335-339
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• 1999

Citrus tristeza virus(CTV), an aphid-borne closterovirus, is one of the most destructive pathogens of citrus. It has caused rapid decline in growth, stem pitting and death in citrus trees. A reverse transcriptase polymerase chain reaction (RT-PCR) assay was developed for detection of CTV and investigation of the CTV infection status of citrus and its related cultivars in Cheju island. For RT-PCR based CTV detection, primers were designed to amplify 670bp of coat protein gene. A screening test for CTV in citrus cultivars was conducted from March to July in 1999. Seventy individual citrus trees representing 9 species of 3 genera were tested. The infection rates of CTV for leaves from the years or older trees of late maturing citrus varieties such as Yuzu (C. junos Sieb. ex Tanaka), Navel orange (C.sinensis Osbeck), Kiyomitanger (C. unshiu x C. sinensis), and Shiranuhi ((C. unshiu x C. sinensis) x C. reticulata) were 100%, 80%, 60%, and 60% respectively. The CTV infection rates in Early satsuma mandarins such as 'Miyagawa Early' Satsuma mandarins (C. unshiu Marc. var. Miyagawa) and 'Okitsu Early' Satsuma mandarins (C. unshiu Marc. var. Okitsu) were 100%, and 60%, respectively. CTV was not detected in Cheju native Dangyooja (C. unshiu Marc. var. Osbeck), Trifoliate orange (Poncirus trifoliata) and Kumquat (Fortunella margarita Swingle). In conclusion, RT-PCR assay can be successfully applied to the detection of CTV in citrus trees.

• Research in Plant Disease
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• v.20 no.2
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• pp.101-106
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• 2014

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) is one of the most important diseases on citrus. Although Satsuma mandarin cultivating mostly in Korea is moderately resistance to canker, occurrence of the disease were more frequently reported since last decade. Like other diseases in citrus, citrus canker was mainly protected by chemical fungicide in the field. Due to the side effect of the chemicals, alternative method of disease control is recently required. In this study four rhizobacterial strains TRH423-3, MRL408-3, THJ609-3 and TRH415-2 are selected by testing its antifungal activity against Xcc. Pre-inoculation with the selected rhizobacterial strains caused disease suppression on the citrus leaves after inoculation with the citrus canker pathogen. Similarly, in the field test symptoms of citrus canker were less developed in the citrus trees applied several times with the selected rhizobacterial strains compared with those of untreated trees. Therefore, it is suggested that the selected rhizobacterial strains may be valuable as an alternative method in the environment-friendly citrus farm.

• Agribusiness and Information Management
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• v.6 no.1
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• pp.1-11
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• 2014

The purpose of this study is to develop the growth prediction model that can predict growth and development information influencing on the production of citrus fruits. The growth model was developed to predict the floral leaf ratio, number of fruit sets, fruit width, and overweight fruits depending on the main period of growth and development by considering the weather factors because the fruit production is influenced by weather depending on the growth and development period. To predict the outdoor-grown citrus fruit production, the investigation result for the standard farms is used as the basic data; in this study, we also understood that the influence of weather factors on the citrus fruit production based on the data from 2004 to 2013 of the outdoor-grown citrus fruit observation report in which the standard farms were targeted by the Agricultural Research Service and suggested the growth and development information prediction model with the weather information as an independent variable to build the observation model. The growth and development model for outdoor-grown citrus fruits was assumed by using the Ordinary Least Square method (OLS), and the developed growth prediction model can make a prediction in advance with the weather factors prior to the observation investigation for the citrus fruit production. To predict the growth and development information of the production of citrus fruits having a great ripple effect as a representative crop in Jeju agriculture, the prediction result regarding the production applying the weather factors depending on growth and development period could be applied usefully.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.271-291
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• 2022

Pectin methylesterase (PME) plays an important role in vegetative and reproductive development and biotic/abiotic stress responses by regulating the degree of methyl-esterification of pectic polysaccharides in the plant cell wall. PMEs are encoded by a large multigene family in higher land plant genomes. In general, the expression of plant PME genes shows tissue- or cell-specific patterns and is induced by endogenous and exogenous stimuli. In this study, we identified PME multigene family members (CsPMEs) from the sweet orange genome and report detailed molecular characterization and expression profiling in different citrus tissues and two fruit developmental stages. We also discussed the possible functional roles of some CsPME genes by comparing them with the known functions of PMEs from other plant species. We identified 48 CsPME genes from the citrus genome. A phylogenetic tree analysis revealed that the identified CsPMEs were divided into two groups/types. Some CsPMEs showed very close phylogenetic relationships with the PMEs whose functions were formerly addressed in Arabidopsis, tomato, and maize. Expression profiling showed that some CsPME genes are highly or specifically expressed in the leaf, root, flower, or fruit. Based on the phylogenetic relationships and gene expression profiling results, we suggest that some CsPMEs could play functional roles in pollen development, pollen tube growth, cross incompatibility, root development, embryo/seed development, stomata movement, and biotic/abiotic stress responses. Our results shed light on the biological roles of individual CsPME isoforms and contribute to the search for genetic variations in citrus genetic resources.

• Korean Journal of Pharmacognosy
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• v.48 no.2
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• pp.134-140
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• 2017

In a series of investigations to develop a potential anti-obese agent, we prepared a immature Citrus fruits (IMF) and compared its lipid excretion effects to those of Citrus fruits (MF, CP, JP) in an ICR mouse model of obesity induced by a high fat diet. The body weights of IMF fed mice were found to be significantly lower from 2 weeks oral administration, despite the fact that their food intakes were similar to that of the HFD control mice. The fecal cholesterol content showed a significant increase in IMF (52.0 mg/g) at 7 weeks oral administration, and mature Citrus fruits (MF, 41.3 mg/g), immature Citrus peel (CP, 32.2 mg/g), mature Citrus peel (JP, 30.0 mg/g) respectively. And also, the triglyceride content in the feces showed a significant increase in MF (14.6 mg/g), and IMF (14.2 mg/g), CP (10.5 mg/g) and JP (10.0 mg/g), respectively. On the other hand, in the inhibition activity of pancreatic lipase, MF (0.78 nmol/min/ml) showed the greatest decrease in glycerol, CP (0.79 nmol/min/ml), JP, (0.93 nmol/min/ml) and IMF (1.42 nmol/min/ml).

• Journal of Applied Biological Chemistry
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• v.44 no.3
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• pp.143-146
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• 2001

Eight flavonoids, including rutin, naringin, hesperidin, quercetin, hesperetin, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone, and tangeretin, in the peels of satsuma mandarin (Citrus unshiu) species of Halla, Gungcheon, Hungjin, Namgam-20, Illnam-1, and Chungdo harvested between August and December were analyzed through HPLC. Hesperidin content of Halla harvested during early maturation was 28.70 mg/g, and was the highest among the tested citrus fruits. Rutin content of Hungjin harvested during early maturation was 2.66 mg/g. Naringin in all citrus species and hesperetin in Halla, Gungchun, Namgam-20, and Chungdo were only detected in the peel of fruits harvested during early maturation. Hesperidin and rutin were detected mainly in all citrus species, and other flavonoids in trace. Flavonoid content in the peel of fruits was high during early maturation. Flavonoid contents in the peels of all fruit samples were generally high in the early stage of maturation, which then decreased rapidly.

• Journal of Radiation Industry
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• v.4 no.3
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• pp.215-219
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• 2010

We have subjected to gamma-irradiation to citrus buds and then grafted onto mature citrus tree. Mutant citrus branch lines have been induced. As a result of first selection, we found the several mutant lines showing interesting phenotypes such as higher sugar content. We have selected several branches showing good qualities such as higher sweetness and/or lower acidity. Some branch lines showed over $13^{\circ}Brix$ sugar content and below 0.9% acidity. Other mutant branch lines showed the changes of shape, size, peel thickness, and fiber contents or distribution of fruits. The results suggest that gamma-irradiation is an effective tool for induction of citrus mutant lines.