• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.279-283
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• 2013

This work was carried out to evaluate the effect of preharvest sprayable 1-methylcyclopropene (1-MCP: $Harvista^{TM}$) treatment on the fruit quality attributes in cold stored 'Gamhong' (Malus domestica Borkh) apples. Preharvest sprayable 1-MCP treatment did not affect fruit qualities at harvest but titratable acidity (TA) was higher in fruit treated 10 days before harvest (DBH) than in control. During cold storage, fruit firmness and TA were higher in 1-MCP treated fruit than in control fruit as storage duration progressed, while SSC was not affected. Internal ethylene concentration (IEC) levels were not different among treatments at harvest. While the IEC level in control fruit reached to $58.3{\mu}L{\cdot}L^{-1}$ after 6 month cold storage, the IEC levels in 1-MCP treated fruit ranged from 18.2 to $25.0{\mu}L{\cdot}L^{-1}$. Therefore, this result indicates that preharvest sprayable 1-MCP treatment should be another promising approach to retain fruit quality attributes in long-term cold stored 'Gamhong' apples.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.440-447
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• 2014

For this analysis, canopies of slender-spindle 'Hongro'/M9 apple trees were divided into 4 positions: upper, lower, exterior, and interior parts. The photosynthetic rate was highest in the external part of the upper canopy of the tree, where it was 4.5 times higher than in the internal part of the lower canopy. This difference was closely associated with differences in light penetration based on canopy position. Analysis of leaf growth characteristics showed that the leaves situated in the internal part of the canopy were larger and thinner than those in the external part of the canopy. The difference in leaf thickness was mainly due to thickness of the primary layer of palisade tissues (68.5 and $110.3{\mu}m$ for internal and external leaves, respectively). Fruit weight and quality were closely related to the extent of light penetration. Fruit weight, soluble solid content, and red skin color were higher in the fruits from the external part of the canopy. Thus, fruit maturity was delayed in the internal part of canopy. The fruit skin and wax layer were thicker in fruits from the internal canopy than in those from the external canopy. Therefore, our results indicate a need for improved light penetration in internal parts of the canopy and for split harvesting depending on maturity at different canopy positions.

• Research in Plant Disease
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• v.23 no.1
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• pp.75-81
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• 2017

In May 2016, 24 peach samples showing abnormal and virus like symptoms were collected in one of major peach producing area, Yeongcheon-si, Gyeongsangbuk-do, Korea. We performed RT-PCR diagnosis for confirmation of viral infection. The diagnostic targets are 17 species of viruses and viroids that quarantine and high risk pathogens when it occur. As a results, seven species of viruses and viroids, including an unreported (Apricot pseudo-chlorotic leaf spot virus, APCLSV) and a quarantine (Peach latent mosaic viroid, PLMVd) species in Korea, were detected. For the sequence analysis of unreported virus, APCLSV, the sequence of coat protein gene were amplified and cloned. The sequence showed 97% nucleotide identity with other APCLSV isolates and compared with other seven species of reported Trichoviruses. This virus was classified as APCLSV based on the sequence and phylogenetic analysis. This isolate was named Yeongcheon. As patterns of APCLSV occurrence, all samples that APCLSV detected were co-infected with Apple chlorotic leaf spot virus (ACLSV). As properties of ACLSV, APCLSV has high possibility of wide spread disease in fruit tree farms in Korea. Therefore, it is necessary to do related researches, such as infection route and influence of disease in commercial orchards.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.352-357
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• 2019

In this study, we investigated the limit temperature range which is effective for dormancy release of 'Hongro' and 'Fuji' apples during the endodormancy period. The germination rate was 50% or more in all treatments except of 'Hongro' $-5^{\circ}C$ treatment. The germination rate of 'Fuji' was 86.3% at the temperature of $-5^{\circ}C$. The concentrations of carbohydrate and mineral components were significantly different between treatments but did not show any tendency or specific change. However, the sorbitol contents of 'Hongro' $-5^{\circ}C$ treatment were higher at 29.62 mg/g than those of 'Fuji', which was not affected for dormancy release. The results of hormone analysis showed that ABA(abscisic acid) and JA(jasmonic acid) in 'Hongro' $-5^{\circ}C$ treatment were respectively 176.48 and 15.72 ng/g. ABA, JA and SA(salicylic acid) contents in 'Fuji' apple tree were significantly lower than those of 'Hongro'. As a result of this study, the limit temperature range effective for dormancy release was different according to the varieties, and 'Hongro' did not affect with 30.3% of germination rate at $-5^{\circ}C$. However, 'Fuji' is 86.3% even at $-5^{\circ}C$ it was suggested that 'Fuji' had a chilling accumulation for dormancy release.

• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.366-372
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• 2021

BACKGROUND: Ammonia is known as a precursor to fine particulate matter, and according to CAPSS, annual ammonia emissions in the agricultural sector were 249,777 tons as of 2018, accounting for about 79.0% of Korea's total ammonia emissions. In particular, ammonia emissions from agricultural land increased by 19,566 tons (10.2%) compared to the previous year. The Ministry of Environment is setting emission statistics using the ammonia emission coefficient developed in Korea in 2008, but researchers in the agricultural field regard it as a coefficient that does not reflect the reality of Korea's agricultural environment. Accordingly, in order to develop ammonia emission coefficients from the cultivation of apples and pears, Korea's representative fruit type, test agricultural land was set in Iksan, Jeollabuk-do. METHODS AND RESULTS: This study attempted to obtain the ammonia emission coefficient by the treatment of the composite fertilizer (N-P₂O₅-K₂O=12-7-9), and the flux was measured using a dynamic flow-through chamber method. As for the chamber, a total of 12 chambers were installed repeatedly in 4 zones and used to develop emission coefficients. Using compound fertilizers during fruit tree cultivation, the ammonia emission coefficient was evaluated as 10.4 kg NH3/ton for pears and 15.3 kg NH₃/ton for apples. The reason why the ammonia emission coefficient according to the use of composite fertilizers was calculated higher for apple cultivation is believed to be due to the relatively high pH concentration of apple orchard soil. CONCLUSION(S): This study may provide basic data for upgrading the ammonia emission coefficient when using composite fertilizers in agricultural land. In the future, it might be necessary to upgrade the calculation of emissions through the development of ammonia and fine particulate matter emission coefficients considering the agricultural environment of Korea.

• Research in Plant Disease
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• v.29 no.1
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• pp.79-81
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• 2023

During the nationwide survey of fire blight, the typical shoot blight symptoms were found on Korean mountain ash (Sorbus alnifolia) which was located near an orchard that produced fire blight on pear trees in Eumseong, Korea, May 2021. To identify the causal agent, we progressed isolation from the symptomatic leaves and shoots. Two white and mucoid colonies were isolated into the pure culture. Two isolates were identified as Erwinia amylovora according to the colony-polymerase chain reaction (PCR) with amsB primers and the phylogenetic tree using 16S rRNA sequences. To test of pathogenicity of two isolates, we inoculated immature pear fruits and understock of apple. We observed necrosis and oozes on immature pear fruits and shoot blight resulting in necrosis on apple shoots six days after inoculation. Colonies were recovered from the inoculated pears and apples, and identity was confirmed through colony PCR for amsB genes. To our knowledge, E. amylovora was first reported on Korean mountain ash native to South Korea.

• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.2
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• pp.75-86
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• 2008

In order to understand geographic genetic variation and relationship among populations of the mason bee (Osmia cornifrons Radoszkowsky), which is used as pollinator for apple tree, we sequenced a portion of mitochondrial (mt) COI gene, which corresponds to "DNA Barcode" region (658 bp) from 81 O. cornifrons individuals collected over eight localities in Korea. The sequence data revealed overall moderate to low genetic diversity within species, with a maximum sequence divergence of 0.76%. Geographically, two haplotypes (BAROC01 and BAROC02) were widespread with a frequency of 82.7%, whereas several haplotypes were found in a locality as a single individual, suggesting that haplotype distribution can be summarized as coexistence of a few widespread haplotypes and several regionally restricted haplotypes. Overall, high rate of per generation female migration (Nm=$1.1{\sim}$infinite) and low level of geographic subdivision ($F_{ST}=0{\sim}0.315$) among localities were characteristic. Although two populations (p < 0.026) were genetically subdivided from the remaining localities, no clear polarity was observed. Taken together, the nature of genetic divergence of the mason bee populations is characterized as one that possessing moderate to low genetic diversity, high gene flow, and wide spread haplotypes with ahigh frequency, concordant with the capability of dispersal in connection with the lack of historical biogeographic barriers.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.271-275
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• 2008

Choline is important an organic compound for normal membrane function, acetylcholine synthesis, lipid transport, and methyl metabolism. In biological tissues and foods, there are multiple choline compounds that contribute to choline content. There are so many analytical methods for choline determination, such as radioisotopic, high-performance liquid chromatography, and gas chromatography/mass spectrometry. However, these existing methods are expensive, unmanageable, and time-consuming. In this study, we modified enzymatic method, which is applicable for the determination of choline in milk and infant formulas, and applied to bovine serum and muscle. The calibration curves were linear with higher correlation coefficients than 0.994. Recoveries obtained by calibration curves from the spiked bovine serum and muscle samples varied between 70.6 and 85.2%. The method may be suitable for use as a routine method in the determination of choline for biological tissue and food samples.

• Korean Journal of Biological Psychiatry
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• v.15 no.4
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• pp.303-309
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• 2008

Objectives : Some reports have suggested that 5-HT5A polymorphism allelic association was associated with depression, however, there has been no report about relationship between the 5-HT5A gene and antidepressant response. We conducted the association study of the 5-HT5A receptor gene polymorphisms (-19G/C,12A/T) and response to citalopram in Korean patients with major depressive disorder(MDD). Methods : A total of 106 patients with major depressive disorder were included in this study. The patient's symptoms were measured by 21-item Hamilton Depression Rating Scale(HAMD) at baseline, week 1, week 2, week 4 and week 8 during citalopram treatment. A Responder to citalopram was defined by 50% reduction of total HAMD scores. To analyze genetic polymorphisms, a polymerase chain reaction based method was used. Results : At week 8, responders were 62, non-responders were 44. No significant differences of genotypes or allelic association in 19G/C and 12A/T polymorphisms were observed between responsive and non-responsive patients. Conclusion : These results do not support the hypothesis that this polymorphism of the HT5A receptor gene is involved in the therapeutic response to citalopram.

• Korean journal of applied entomology
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• v.34 no.1
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• pp.53-60
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• 1995

This paper discusses scientific books and journal articles in the fields of Entomology, Plant Pathology, Weed Science and Sericulture of North Korea. Most research in the fields of plant protection and sericulture are carried out in the respective research institute of their Academy of Agricultural Sciences. But scientific papers are published in a general agricultural journal. "Bulletin of Korean Academy of Agricultural Sciences", in the case of those in the field of plant protection and in a more specific journal. "Sericulture", in the case o the other. The main interests of entomologists, plant pathologists and weed scientists seem to be how to control pests on rice, com and apple. They do not appear to have many kinds of agricultural chemicals and concentrate their control strategy on the basis of non-chemical mans. Research papers in sericulture are evenly divided between on the silkworm and the mulberry tree, including their pest control.