• Journal of Korean Society of Forest Science
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• v.27 no.1
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• pp.1-4
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• 1975

Freezing resistance of apple (Malus pumila) cultivars was measured to find out the most cold hardy apple variety among the five cultivars which are promissing in Korea. The measurement of freezing resistance for two varieties of dwarf interstock, was also included to compare the cold hardiness among scions and interstocks. The freezing resistance was in order from lowest to highest; winter bud, cambium, xylem ray parenchyma and bark cortex in all cultivars except EM26. The difference in cold hardiness among cultivars and interstocks was not consistent among tissue parts of twig except in cultivar Nugget-spur of which all tissue parts showed least cold hardiness. The difference among tissue parts with in a cultivar was discussed in terms of choosing the most cold hardy, and the most resistant cultivars to late frost damage.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.80-82
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• 2019

Pseudomonas syringae pv. syringae strain WSPS007 was isolated from infected twigs (Malus pumila) in 2013 in Yeongju, Gyeongbuk Province, Republic of Korea. Here, we report the draft genome sequence of WSPS007 with a chromosome size of 6,238,498 bp (59.04% G+C content). The genome comprises 5,379 CDS, 16 rRNA genes, and 65 tRNA genes. The P. syringae pv. syringae strain WSPS007 genome possesses an ice-nucleating activation (INA) gene and an antifreeze operon that may be related to frost damage by this pathogen. Thus, the genome sequence determined in this study will be useful in understanding the relationship between the outbreak of bacterial shoot blight disease and frost damage in northern Gyeongbuk Province.

• Research in Plant Disease
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• v.24 no.4
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• pp.321-327
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• 2018

In 2018, symptoms of black rot on apple (Malus pumila var. dulcissima KOIDZ) cv. Fuji were observed in Yeongcheon-si, Korea. The fruit decay symptoms consisted of purple pimples spots, black rot around the seed cavity (calyx end), mummified fruit. To isolate the causal agent, small fragment (2 to 3 mm) of decayed tissue from the lesion margin were placed on WA or PDA. Fungal colonies on PDA produced dense white aerial mycelium, becoming dark gray with age. Pycnidia and conidia were observed under a light microscopy. The shapes of conidia were aseptate, ovoid, rounded at both ends, and $21.7-28.3{\times}9.9-15.3{\mu}m$. Based on morphological and cultural characteristics, this fungus was identified as Diplodia seriata. To confirm its identity, two loci (ITS and ${\beta}$-tubulin) were sequenced for molecular identification. BLAST searches indicated 100% identity with D. seriata. A pathogenicity test was conducted with isolates on Fuji apples. The apples were inoculated with mycelial plugs (5 mm) from 7-day-old cultures of the putative pathogens. All inoculated apples developed rot symptoms identical to the original symptoms, from which D. seriata were reisolated, fulfilling Koch's postulates. This study is the first report of black rot caused Diplodia seriata on apple.

• Food Science and Preservation
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• v.30 no.3
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• pp.369-382
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• 2023

We examined the changes in the physicochemical quality characteristics and antioxidant activity of fresh-cut Fuji apples (Malus pumila) during processing and storage after treatment with browning inhibitors. The primary aim was to elucidate processing suitability and storability. We observed that in the processing stage of slicing fresh Fuji apples, there were no significant differences in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging ability and ferric-reducing antioxidant power (FRAP). However, after NaClO treatment, total flavonoid and total polyphenol contents decreased. When freshcut Fuji apples were treated with browning inhibitors and stored at 4℃, the L value and hardness decreased; however, the weight loss rate increased based on the storage period of all fruit groups treated with Citrus unshiu Markovich (CuM), calcium ascorbate (CA), and ascorbic acid (AA). The pH increased after 2 days of storage in 1% CuM and after 6 days of storage in 1% CA; however, no changes in pH were observed during the storage period in 1% AA. The DPPH radical scavenging activity was generally good under storage conditions of 1% AA at 4℃ and 1% CA at 20℃. Furthermore, FRAP remained relatively constant under storage conditions of 1% CA. The quality characteristics and antioxidant activity of fresh-cut fruits during processing and storage can be used as basic data for industries. Furthermore, we can gain confidence in quality improvements by improving the production and distribution environment of fresh-cut agricultural products.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.43-50
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• 2020

In this study, the anti-oxidative, health functional, and beauty food activities of water and ethanol extracts from newly bred Ruby S apple (Malus pumila Mill.). The results of measuring the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity by treating the phenolic compound with thinning green ball apple at a concentration of 50-200 ㎍/mL showed that the water and ethanol extracts at a concentration of 200 ㎍/mL showed 94.69 and 92.24%, respectively. 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities showed 100.30 and 99.16%, respectively, in 200 ㎍/mL of water and ethanol extracts. The water and ethanol extracts of Green ball showed antioxidant protection factor of 1.76 PF 1.76, respectively. The water and ethanol extracts showed 101.46 and 99.64% anti-oxidative effect on thiobarbituric acid reactive substances at phenolic concentration of 200 ㎍/mL. The water and ethanol extracts showed 33.28 and 32.14% hyaluronidase inhibition, respectively, at phenolic concentration of 150 ㎍/mL. The water and ethanol extracts showed 47.33 and 40.92% elastase inhibition and 46.19 and 65.58% collagenase inhibition at phenolic concentration of 200 ㎍/mL, respectively. About these experiments, thinning Green ball apple was found to exhibit anti-oxidation activity as well as hyaluronidase, elastase and collagenase inhibitory activities. Therefore, thinning Green ball apple can be considered a potential sources for new functional materials.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.187-193
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• 2019

The newly bred Picnic apple was extracted using water and ethanol for extracting solvent. Each water and ethanol extract showed relatively high phenolic compound of 3.69 and 5.55 mg/g. Each water and ethanol extract of Picnic apple showed 1,1-diphenyl-2-picrylhydrazyl of 88.10 and 88.07%, 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) of 98.79 and 97.25%, antioxidant protection factor of 2.07 and 2.00 PF and thiobarbituric acid reactive substances showed anti-oxidation effect of 9.69 and 19.83% all at $100{\mu}g/mL$ phenolics concentration. Therefore extract of Picnic apple can be considered as anti-oxidant for anti-aging. The anti-inflammatory effect (hyaluronidase inhibition) of extract of Picnic apple were 4.62% with water extract and 4.39% with ethanol extract both at $200{\mu}g/mL$ phenolics concentration. Both water and ethanol extract showed low ${\alpha}$-amylase inhibition effect but each showed 67.37 and 79.16% of ${\alpha}$-glucosidase inhibition effect at $200{\mu}g/mL$ phenolics concentration. In anti-wrinkle effect, water extract showed each 23.70 and 66.29% in elastase inhibition and collagenase inhibition and ethanol extract showed 64.83 and 65.70% each. These result show high potential for functional food and cosmetic source. Picnic apple was identified to have various functions of anti-oxidation, anti-inflammation, anti-wrinkle effect, and anti-diabetic effect. Therefore, Picnic apple is qualified as a source for new functional cosmetics and functional foods.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.228-235
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• 2019

Apple (Malus pumila) is one of the most economically important fruits in Korea. but virus infection has decreased the sustainable production of apples and caused serious problems such as yield loss and poor fruit quality. Virus or viroid infection including apple chlorotic leaf spot virus (ACLSV), apple stem pitting virus (ASPV), apple stem grooving virus (ASGV), apple mosaic virus (ApMV) and apple scar skin viroid (ASSVd) have been also reported in Korea. In many cases, as apple gets infected with virus and viroid with no specific symptoms, the damage and symptoms caused by the viruses are not detected. In our research, viruses in the rootstock were eliminated for a virus-free apple dwarfing rootstock of M.9 and M.26. The virus elimination methods were apical meristem culture, thermotherapy ($37^{\circ}C$, 6 weeks) and chemotherapy($Ribavirin^{(R)}$). The detection of apple viruses was accomplished by Enzyme-linked Immuno-Sorbent Assay (ELlSA) and reverse transcription-polymerase chain reaction (RT-PCR). RT- PCR method was 10 ~ 30% more sensitive than the ELISA method. The efficiency of virus elimination was enhanced in apical meristem culture method. The acquisition rate of virus-free apple dwarfing rootstocks was 30 ~ 40% higher in apical meristem culture. After the meristem culturing of M.9, the infection ratio of ACLSV, ASPV and ASGV was 45%, 60% and 50%, respectively. In the apple dwarfing rootstock of M.26, the infection ratio of ACLSV, ASPV and ASGV was 40%, 55% and 55%, respectively. Based on this study, the best method for the production of virus-free apple dwarfing rootstocks was the apical meristem culture.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.289-302
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• 2013

Surveys were conducted to study nationwide distribution and identify habitats and host plants of Cuscuta pentagona Engelm. as a parasite. The major habitat types were arable land near agricultural waterways (54.3%), open field near roadside (41.3%) and artificial grassland (4.3%). The investigated host plants of Cuscuta pentagona consist of total 130 taxa: 10 varieties, 1 subspecies, 119 species, 95 genera, and 37 families. Among them, 30 taxa were alien plants. As for the useful plants, there were 59 taxa of edible ones (45.4%), 54 taxa of medicinal ones (41.5%), 13 taxa of ornamental ones (10%), 13 taxa of industrial ones (10%), and 9 taxa of pasture ones (6.9%). On arable land, it caused damage particularly to the growth of agricultural crops such as Oryza sativa L. (Rice) and fruits such as Malus pumila Mill. (Apple) etc. Its growth and distribution may cause economic loss for crops because of the close location of the arable land.

• The Korean Journal of Pesticide Science
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• v.5 no.4
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• pp.27-32
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• 2001

Methanol extracts from 43 materials of 17 fruit trees were tested for their insecticidal activities toward five agricultural and four stored-product anthropod pests. Efficacy varied with insect species, plant species, and tissue sampled. At a concentration of 2,500 ppm, strong activity was observed with extracts of Chaenomeles sinensis and Punica granatum seeds against Myzus persicae adult females, Vitis vinifera seeds against Nilaparvata lugens adults, Citrus junos, Citrus paradisi, Cucumis melo Linne var. reticulatus, Diospyros kaki, Malus pumila var. dulcissima, Prunug persica, and V. vinifera seeds against Plutella xylostella, Citrus sinensis seeds against Spedoptera litura larvae, and Ch. sinensis and V. vinifera against Tetranychus urticae adults. Against four stored-product insect pests at 50 ppm, seed extracts of Ch. sinensis and V. vinifera against Sitophilus oryzae adults, and Ch. sinensis, C. junos, D. kaki, and V. vinifera against Callosobruchus chinensis adults gave over 80% mortality. Extracts of all samples exhibited little and no activity against Lasioderma serricorne adults and Plodia interpunctella larvae.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.41-48
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• 1984

The soil bacterium Agrobacterium tumefaciens is a plant pathogen that cause3 crown gall tumors by infecting the wounded dicotyledonous plants and subsequent integration of bacterial DNA into plant nuclear DNA. Virulent A. tumefaciens strains harbor a large Ti (tumor-inducing) plasmid that carries genes essential for tumorigenesis. In the present study, 13 strains (Malus pumila Mill; $A_{1-3}$, Populus monilifera; $W_{1-6}$, Populus tomentiglandlosa; $P_{1-3}$ and Rosa species; $R_1$) of Agrobacterium isolated in korean crown gall tumors and plasmids were observed in 6 strains ($W_2$, $W_3$, $W_6$, $P_1$, $P_3$ and $A_2$). The test for crown gall tumor formation was resulted only in ATCC15955 and $KW_2$ strains inoculated into the stem of sun flower and the development was observed for 4 and 6 weeks after inoculation. Above two Ti plasmids (pTi) were purified by cesium chloride-ethidium bromide density gradient centrifugation and digested with restriction enzyme and fragments of pTiATCC 15955 and $pTiKW_2$ observed by EcoR I ; 25&27, Hind III; 23&21, BamH I ; each 20 and Hpa I ; 12&27, and sizes of pTiATCC15955 and and $pTiKW_2$ calculated as 200 and 87 kbases. Octopine was isolated from tumor tissue ($W_{1-6}$ and $P_{1-3}$) and these strains confirmed as octopine type.