• Mycobiology
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• v.48 no.3
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• pp.210-218
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• 2020

Peach (Prunus persica L.) is one of the major fruit crops in South Korea, along with apple, persimmon, and Asian pears. Peach anthracnose is a continuing threat to growers and is accountable for enormous economic loss. In July 2018, anthracnose of peach appeared at different peach orchards in Gyeongsangbuk-do region, Korea. The typical anthracnose symptoms (brown, circular, and necrotic lesions) were observed on the fruits. Anthracnose of peach was surveyed in different peach orchards of Gyeongsangbuk-do, and 20 fungal isolates from 19 diseased fruits were collected. Multigene phylogenetic analyses coupled with morphological characteristic analysis approaches were used for identifying the fungal species isolated from diseased fruits. This study confirmed three Colletotrichum species. Based on the results, Colletotrichum siamense are reported for the first time as causal agents of peach anthracnose alongside C. fructicola and C. fioriniae, which has been reported previously. Pathogenicity assays were performed for the three isolates representing all the species identified, and Koch's postulates on detached healthy peach fruits were verified. All the identified species were pathogenic on peach fruits as the typical anthracnose symptoms were reproduced. Significant variations in the virulence were observed among fungal species on peach fruit.

• Korean Journal Plant Pathology
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• v.14 no.1
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• pp.99-101
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• 1998

A severe brown rot on peach fruit caused by a Phytophthora sp. has occurred at peach orchards in Taegu of Korea from late June to early August in 1997. Infected fruits showed irregularly round or circular water soaking brown regions. In the severe case, fruits were entirely rotten and surface of the fruits were wrinkled. Occasionally, white mycelia and abundant sporangia were developed on the surface of fruit. Inner tissues of the fruits were also discolored to brown. The causal fungus was identified as Phytophthora cactorum based on following characteristics. Sporangia were ovoid, conspicuously papillate, caducous and measured as 28.4~48.1$\times$21.9~37.2 (av. 39.9$\times$30.4) ${\mu}{\textrm}{m}$. Sexuality of the fungus was homothallic. Oogonia were 25.0~34.0 (av. 29.9) ${\mu}{\textrm}{m}$ in size. Most antheridia were paragynous and measured av. 10.5$\times$13.0 ${\mu}{\textrm}{m}$. Optimum temperature for mycelia growth was around 25~3$0^{\circ}C$. However none of the isolates grew under 7$^{\circ}C$ and over 35$^{\circ}C$. The fungus revealed high pathogenicity to fruits, shoots and leaves of peach, apple and pear with different degrees. Phytophthora fruit rot of peach caused by Phytophthora cactorum has not been reported in Korea previously.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.737-754
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• 2019

Peaches have soft tissues compared to other fruits and are vulnerable to softness, wounds, and loss of marketability due to the weak fruit hardness after harvest. It is necessary to develop a technology to improve the shelf-life of the fruit to expand the distribution of peaches. Calcium compounds and chitosan have an important role in improving the shelf-life of fruit by maintaining the hardness and reducing the respiration rate in peach fruits. In this study, to select useful compounds to improve the shelf-life of peaches, calcium citrate, calcium chloride, calcium nitrate, GH-Ca, OS-Ca, chitosan, and chitosan dissolved in calcium chloride were sprayed onto peach trees. The characteristics of the harvested fruits were investigated after the 'Kumhong' and 'Madoka' peach tree treatments. The hardness of the fruit was kept the highest with the combined treatment and remained high with the calcium citrate, chitosan and calcium nitrate treatments. Ethylene production and respiration were effectively inhibited by the GH-Ca and chitosan treatments. There was no significant difference in soluble solids content and acidity among the fruits treated with the chemicals. The coloration of the fruit skin was not delayed by the calcium and chitosan chemical treatments. Calcium compounds were increased in the fruits and leaves of the peach trees treated with the chemicals compared to the untreated ones. These results suggest that the calcium treatment extended the shelf-life by increasing the calcium content in the leaves and fruits of the peach trees.

• Food Science and Preservation
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• v.12 no.6
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• pp.511-515
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• 2005

The responses of 'Tsugaru' apple and 'Baekhyang' peach fruits treated with 1-MCP, the ethylene inhibitor, were compared. In Tsugaru apple fruits, the reduction of flesh firmness and titratable acidity were significantly retarded for 2 weeks by the treating fruits with 1 or 5 ppm of 1-MCP immediately after harvest The respiration decreased continually for 2 weeks and the onset of ethylene production were also retarded severely. However, in Baekhyang peach fruits, the effects of 1-MCP treatment on the respiration and ethylene production were only transient and the firmness reduction was retarded slightly by the repeated 1-MCP treatments. The responsiveness of the Baekhyang peach fruits on ethylene seems to be recovered rapidly after 1-MCP treatment. In case of Baekhyang fruits, the 1-MCP should be treated repeatedly for effective ethylene inhibition, and the ethylene accumulation should be avoided during the 1-MCP treatment.

• Mycobiology
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• v.28 no.4
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• pp.177-179
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• 2000

A soft rot of fruits caused by Rhizopus nigricans occurred on peach (Prunus persica var. vulgaris) in The Chinju City Agricultural Products Wholesale Marke during in summer season of 2000. The disease infection usually started from wounding after harvest fruits, and then moved to outside. At first, the lesions started with water soaked and rapidly softened and diseased area gradually expanded. In severely infected film house, the rate of infected fruits reached 65.2%. Numerous sporangiospores were produced on the diseased fruits. Most of the sporangiospores were appeared to be readily dispersed in the air. The mycelia grew surface of fruits and produced stolons. Colonies on potato dextrose agar at $25{\sim}30^{\circ}C$ white cottony at first becoming heavily speckled by the presence of sporangia and the browinish black at maturity, spreading rapidly by means of stolons fired at various points to the substrate by rhizoids. Sporangia were $85.3{\sim}243.5{\times}53.4{\sim}219.2\;{\mu}m$ in size and were globose or sub-globose with. somewhat flattened base. The color of sporangia was white at first and then turned black with many spores, and never over-hanging. Sporangiophores were $8.9{\sim}36.6\;{\mu}m$ in width, smooth-walled, non-septate, light brown, simple, long, arising in groups of $3{\sim}5$ from stolons opposite rhizoids. Sporangiospores was $9.7{\sim}24.8{\times}5.9{\sim}15.8\;{\mu}m$, irregular, round, oval, elongate, angular, and browinish-black streaked. Columella was $70.2{\times}149.7{\mu}m$. brownish gray, and umberella-shaped when dehisced. The causal organism was identified as. Rhizopus nigricans Lind on the basis of the morphiogical characteristics of the fungus. Rhizopus soft rot on peach (Prunus persica) caused by the fungi has not been reported in Korea. This is the first report of rhizopus soft rot on peach caused by Rhizopus nigricans in Korea.

• Research in Plant Disease
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• v.26 no.1
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• pp.48-52
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• 2020

In July 2019, typical rot symptom was observed on peach fruits harvested from the fields at Andong, Korea. As the disease progressed, white and purple colored mycelial mat developed on the surface of the infected fruits. A causal pathogen was isolated from the infected fruit and cultured on potato dextrose agar media for identification. Fungal colonies on potato dextrose agar produced 3 pigments, including purple, yellow, and white colors. The isolate incited fruit rot symptoms on artificially inoculated peach fruits, from which the same fungus was isolated, fulfilling Koch's postulates. Based on the morphological characteristics and sequence analysis of rDNA internal transcribed spacer, translation elongation factor 1-alpha, and β-tubulin, the causal agent of the disease was identified as Fusarium avenaceum. This study is the first report of fruit rot of peach fruits caused by Fusarium avenaceum in Korea.

• Journal of Biosystems Engineering
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• v.34 no.3
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• pp.183-189
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• 2009

Environmental conditions may cause the quality change of fruits during distribution after harvest. In order to prevent the damage or quality change of fruits for distribution, the characteristic of fruits affected by the environmental conditions such as temperature, humidity under various distribution conditions should be known. This research was performed to analyze how the environmental conditions affect the factors such as weight loss rate and ethylene production of the peach under several distribution conditions. Environmental conditions of the actual distributed route were evaluated and the data obtained from the conditions were used for the simulated environmental tests. Regression models of the weight loss rate and the ethylene production of peach were developed and used in predicting peach quality. The weight loss rate of the peach estimated by the ASHRAE data was shown the higher value on the transportation temperature condition than on the low and room temperature conditions. The weight loss rate and the ethylene production of the peach on the simulated distribution conditions were measured and the measured weight loss rate of peach was the smaller than the theoretically estimated one. The regression models of the weight loss rate and the ethylene production were developed respectively.

• Food Science and Preservation
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• v.15 no.4
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• pp.593-597
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• 2008

This study was performed for obtaining optimal extraction conditions to produce peach liqueur containing chitosan. Alcohol content of unsliced fruits was the largest recording 30% after extracting for 8 weeks and those of fruits sliced into four pieces were high recording around 28% after extracting for $6{\sim}8$ weeks. Sugar content was $11{\sim}13^{\circ}Brix$, total acidity was around 0.2% and pH was about 4.8. While soluble solids content was around 2.8% in unsliced fruits with a little change of the content, those of fruits sliced into four pieces were ranged from 2.8% to 3.1% and showing a tendency that longer extraction time increased the content. Brownness of unsliced fruits and fruits sliced into four pieces were $0.33{\sim}0.54$ and $0.56{\sim}0.73$ respectively. Total phenol content showed a similar tendency with brownness and the total phenol content of sliced fruits was higher than that of unsliced fruits by only around 0.2 mg%. When peach liqueur was made by extracting unsliced fruits massively by following conditions set above, methanol content grew with longer extraction time but the difference was not significant and the content was detected to be extremely small recording about 50 ppb. Among organic acids, oxalic, malic and citric acids were found, and fructose, glucose, sucrose and maltose were detected as free sugars. In conclusion, extracting unsliced fruits for 8 weeks as extraction conditions showed an excellent quality in overall for peach liqueur containing chitosan.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.174-176
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• 2006

The experiments were conducted by supplying hosts with natural food(chestnut, peach, Quince). The developmental difference of peach pyralid moth, Dichocrocis punctiferalis was examined in the laboratory under three different natural food regime. The periods of egg, larva and pupa were $6.01{\pm}0.07$, $12.23{\pm}0.03$ and $13.32{\pm}0.01$ days on the chestnut fruit, $6.21{\pm}0.01$, $18.69{\pm}0.02$ and $13.38{\pm}0.03$ days on the peach fruit and $7.02{\pm}0.04$, $22.62{\pm}0.04$ and $13.44{\pm}0.14$ days on the quince fruit, respectively. The growth of D. punctiferalis larva was better chestnut fruit than other tested fruits. The rates(%) of hatching, pupation and emergence were 94.0, 57.0 and 63.3 on the chestnut fruit, 89.2, 77.8 and 85.7 on the peach fruit and 79.6, 52.6 and 70.7 on the quince fruit, respectively. The survival rate(%) of D. punctiferalis from hatching to emergence were 31.0 on the chestnut fruit, 4.8 on the peach fruit and 14.3 on the quince fruit, respectively. The sex ratio (female: male) of all pupae obtained on the tested natural food fruits were 52.7 : 47.3. The sex ratio of D. punctiferalis reared on three difference food fruits were no significantly. It can be used a as the basic research for the study of D. punctiferalis.

• The Plant Pathology Journal
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• v.24 no.1
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• pp.80-83
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• 2008

Anthracnose symptoms were frequently observed on fruits of peach trees grown in Yeongi in Korea during disease survey in August from 2000 to 2005. The disease incidence was as high as 40% at its maximum in the orchards investigated. A total of 24 isolates of Colletotrichum species were obtained from the anthracnose symptoms, out of which 20 were identified as Colletotrichum gloeosporioides and the four remaining ones as C. acutatum based on their morphological and cultural characteristics. Two isolates of each C. gloeosporioides and C. acutatum caused anthracnose symptoms on the fruits by both wound and unwound inoculation, which were similar to those observed in the orchard. The symptoms appeared more rapidly by the wound inoculation than by the unwound inoculation. There was no difference in pathogenicity between the C. gloeosporioides and C. acutatum isolates tested. In Korea, only C. gloeosporioides has been recorded as the causal fungus of anthracnose of peach tree. This is the first report that C. acutatum also causes anthracnose of peach tree in Korea.