• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.405-405
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• 2005

• Horticultural Science & Technology
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• v.16 no.4
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• pp.514-516
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• 1998

This study was conducted to observe the effects of urea foliar spray to replace soil fertilization on defoliation ratio, shoot growth and fruit setting in satsuma mandarin (Citrus unshiu Marc.). Twice foliar sprays of 1% urea after harvest increased N and chlorophyll contents in leaves, and decreased defoliation during the winter season. The growth of the ovary and spring shoot was stimulated by the twice 0.8% urea foliar spray around the time of bud emergence. In addition, the treatments increased the number of flowers and fruit setting, but didn't influence fruit quality.

• Food Science and Preservation
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• v.5 no.4
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• pp.339-341
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• 1998

The changes of freshness from the several transportation methods and the effect of low temperature transportation for Satsuma Mandarin (Citrus unshiu Marc. Var. okitsu) fruit were investigated to get informations on keeping freshess and good taste. There were 695 lower in fresh weight, 1.91mg lower in vitamin C and 20% higher in sugar acid rate for citrus fruit after room temperature (17$^{\circ}C$) transportation than low temperature transportation (5$^{\circ}C$), respectively. The loss of freshness md tasting was caused by the weight loss of citrus fruit because the sugar acid rate was increased in room temperature (from 16.11 to 21.75). Therefore, it is desirable for citrus fruit to transport in low temperature to keep high quality and freshness.

• Applied Biological Chemistry
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• v.41 no.3
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• pp.228-233
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• 1998

The storage life of satsuma mandarin(Citrus unshiu Marc. var. miyagawa) by the various pretreatment of temperatures; non-treated, room temperature, $10,\;20^{\circ}C$ and $35^{\circ}C$ were investigated. The pretreated citrus fruits were stored at $4^{\circ}C$, 85% relative humidity. Weight loss of citrus fruits by the pretreatment at $35^{\circ}C$ for 24 hrs was the lowest among that of others. Decay ratio of $35^{\circ}C$ pretreated fruits was increased at initial stages of storage, but was maintained low level after that, compared to other treatments. After 115 days storage, firmness of fruits was lowered by the softening, and decayed fruits were occurred increasingly. Ethylene evolution was increased between $55{\sim}65$ days after storage, and the amount was increasing rapidly after 115 days. It seemed to be derived from decayed fruits and physiological activities. $CO_2$ content in fruit was decreased at initial stages of storage, but was increased between $55{\sim}100$ days during storage periods. Acid content, soluble solids, total sugar and vitamin C were reduced gradually during cold storage, but the difference among treatments was not so great. Pretreated fruits at $35^{\circ}C$ for 24 hrs before cold storage was effective on preventing from weight loss and respiration ratio. Optimum storage period of early variety of Satuma mandarin was regarded for 100 days on the basis of appeareance and taste.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.120.3-121
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• 2003

Relative degree of resistance of citrus to Xanthomonas axonopodis pv. citri, the causal bacterium of canker, was investigated. Growth rate of a bacterium in leaf tissues after infiltration, disease incidence, and percent of lesion area were compared. By using growth rate[(GR=(At - A$\sub$t-1/)/A$\sub$t-1] host plants were differentiated into susceptible and resistant. Growth rates reached to peak at 40 hrs after inoculation and then declined. The growth rate in leaf tissues of a moderately susceptible cultivar, Citrus sinensis vu. Lane late(sweet orange), was the highest, and those of C. unshiu ${\times}$ C. sinensis(kiyomi), C. junos(yuzu), [(Citrus. unshiu x C. sinensis) x C. reticulata] (shiranuhi), and C. unshiu(satuma mandarin) were similar. This result indicates that the growth rate of the bacterium in leaf tissues can be effectively used for evaluation of disease resistance for citrus plants to X. axonopodis pv. citri. The disease on sweet orange occurred earlier than relatively resistant citrus plants tested. The percent of lesion area on leaf was also higher in sweet orange than those of satsuma mandarin, shiranuhi and kiyomi, and yuzu. The disease severity was highest on sweet orange and followed by kiyomi, shiranuhi, satsuma mandarin, and yuzu.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.145.2-146
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• 2003

To investigate occurrence and variability of satsuma mandarin ( Citrus unshiu)-infecting viruses in Jeju island, several sets of diagnostic RT-PCR primers were designed and applied to samples collected randomly. Each primers set used in this survey was designed to detect Satsuma dwarf virus (SDV, Sadwavirus) and Citrus mosaic virus (CiMV) which is reclassified as an isolate of SDV (SDV-CiMV, Saduavirus). RT-PCR methods could detect SDV-CiMV and CTV from leaf . samples of unshui citrus. CTV was the prevalent and SDV-CiMV was not common in Jeju island. RT-PCR product of SDV-CiMV-JJl2 were cloned and sequenced. Sequence of the isolate revealed that it was 96.9 ％ identical to SDV-CiMV-Jp isolate at the nucleotide level. SDV-CiMV-JJl2 was propagated on Physalis floridana and sequencing of entire sequences of genome is in progress. Variability of SDV in Jeju island was confirmed by sequence comparisons and restriction mapping analysis.

• The Plant Pathology Journal
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• v.16 no.1
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• pp.48-51
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• 2000

Citrus tristeza virus (CTV) was identified form CTV-infected early satsuma mandarin (Citus unshiu) and yuzu (C.junos) by RT-PCR. The total RNAs were isolated from citrus bark and seaf tissues infected with CTV and reverse transcription was followed with primers designed for amplifying CTV coat protein gene. DNA fragments 738 bp were amplified by RT-PCR and these products were colned for sequence analysis. Based on the sequence analysis, this PCR product has 97% sequence homology to CTV (T-385) CP gene isolated from USA. RT-PCR assay for CTV detection was more sensitivity than ELISA assay which was done with anti-CTV CP antibody. This is the frist report about CTV identification in Cheju island Korea.

• 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.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.642-649
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• 2012

The study was conducted to investigate the effect of fruit bearing type with leafy (LY) and leafless (LS) fruits on fruit growth, sugar, and acid characteristics in satsuma mandarin. Fruit growth including fruit length, diameter, shape index (diameter/length), weight, and size distribution was not different between LY and LS fruits at ripening time. Total soluble solids (TSS) concentration of the fruit juice increased and acidity decreased continuously and then TSS:acidity ratio increased with fruit development from 100 days after anthesis to ripening time. Soluble sugar was continuously increased, whereas organic acid decreased. Theses tendencies were related to the increase of sucrose and decline of citric acid, respectively. However, there was no effect of fruit bearing type on TSS, acidity, and TSS:acidity ratio, and soluble sugar and organic acid composition in fruit juice. Also, photosynthetic rate and chlorophyll index with SPAD value were not different between leaves adjacent to LY and LS fruits. The results indicated that fruit growth and sugar and acid characteristics were not affected by fruit bearing type with leafy and leafless fruits in satsuma mandarin.

• Applied Biological Chemistry
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• v.40 no.4
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• pp.313-317
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• 1997

To assess the physiochemical characteristics of greenhouse Satsuma mandarin (Citrus unshiu Marc. var, miyakawa) produced in Cheju, were analyzed chemical compositions for fruits, external and internal factors influencing the edible quality. Changes in organoleptic value according to brix and acid content were also evaluated. The ratios of sucrose : glucose : fructose in citrus juice were 2 : 2 : 1.5. Citric acid as the main acid in the juice represented about 70% of total organic acid. Most of the amino acids were found to be nonessential amino acids. Deep yellow color of the citrus peel showed a significant relationship(r=0.563) with brix/acid ratio of the citrus juice, indicating the ripeness of the fruit. Since the acid content showed highly negative statistical relationship(r= -0.882) with the pH value of the juice, the pH value appears to be a simple indicator for the sourness of the fruit in the field test. The fruits were divided into 9 groups based on the brix/acid contents for sensory evaluation. The palatability patterns of each group changed depending on the acid content. The optimal ranges of brix/acid content for acceptable taste were 11 and $0.5{\sim}1.0$, respectively.