• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.75-75
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• 2018

Watermelons, Citrullus species(Cucurbitaceae), are native to Africa and have been cultivated since ancient times. T he fruit flesh of wild watermelon is watery, but typically hard-textured, pale-colored and bland or bitter. The familiar sweet dessert watermelons, C. lanatus, featuring non-bitter, tender, well colored flesh, have a narrow genetic base, suggesting that they are originated from a series of selection events in a single ancestral population. In this study, considered as sweet dissert watermelon, genetic resources, C. lanatus, comprising of traditional cultivars and local accessions were collected from 18 different countries in four continents. A total of 60 accessions were characterized morphologically according to RDA genebank descriptors combined with Japan and China, list for 11 qualitative characteristics, leaf length, leaf width, petiole length, petiole diameter-source, stalk end length, stalk diameter, fruit length, fruit diameter, rind thickness, flesh sugar content($^{\circ}brix$), fruit weight-sink, and 6 sink related characters, leaf margin incision-source, fruit shape, fruit skin ground color, fruit skin stain color, fruit skin stain pattern and flesh color-sink, were also investigated. Even though the relatedness between some morphological traits and fruit weight or fruit sweetness showed no significance, the accessions investigated have a great deal of variation for most of the morphological traits. Additionally, the accessions which showed good performance in flesh color and fruit shape (IT271048) and high sugar content of flesh (IT274119, IT290118) above 14brix, were investigated in this experiment. The accessions, which have the information on specific traits including the selected accessions could be introduced, distributed and investigated for further use.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.73-73
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• 2018

Bacterial leaf blight(BLB), caused by X. oryzae pv. oryzae(Xoo), is one of the most destructive diseases of rice due to its high epidemic potential. Understanding BLB resistance at a genetic level is important to further improve the rice breeding that provides one of the best approaches to control BLB disease. In the present investigation, a collection of 192 accessions was used in the genome-wide association study (GWAS) for BLB resistance loci against four Korean races of Xoo that were represented by the prevailing BLB isolates under Xoo differential system. A total of 192 accessions of rice germplasm were selected on the basis of the bioassay using four isolated races of Xoo such as K1, K2, K3 and K3a. The selected accessions was used to prepare 384-plex genotyping by sequencing (GBS) libraries and Illumina HiSeq 2000 paired- end read was used for GBS sequencing. GWAS was conducted using T ASSEL 5.0. The T ASSEL program uses a mixed linear model (MLM). T he results of the bioassay using a selected set of 192 accessions showed that a large number of accessions (93.75%) were resistant to K1 race, while the least number of accessions (34.37%) resisted K3a race. For races K2 and K3, the resistant germplasm proportion remained between 66.67 to 70.83%. T he genotypic data produced SNP matrix for a total of 293,379 SNPs. After imputation the missing data was removed, which exhibited 34,724 SNPs for association analysis. GWAS results showed strong signals of association at a threshold of [-log10(P-value)] more than5 (K1 and K2) and more than4 (K3 and K3a) for nine of the 39 SNPs, which are plausible candidate loci of resistance genes. T hese SNP loci were positioned on rice chromosome 2, 9, and 11 for K1 and K2 races, whereas on chromosome 4, 6, 11, and 12 for K3 and K3a races. The significant loci detected have also been illustrated, NBS-LRR type disease resistance protein, SNARE domain containing protein, Histone deacetylase 19, NADP-dependent oxidoreductase, and other expressed and unknown proteins. Our results provide a better understanding of the distribution of genetic variation of BLB resistance to Korean pathogen races and breeding of resistant rice.

• Korean Journal of Plant Resources
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• v.33 no.4
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• pp.293-302
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• 2020

Morphological characteristics of Ziziphus jujuba accessions, including 'Ilbon', were investigated to verify the possibility of 'Ilbon' as a breeding material. 'Ilbon' has smaller leaves and fruits and a lower total soluble solids content compared to the major Z. jujuba accessions. However, total polyphenol content and antioxidant capacity were highest in 'Ilbon' among the Z. jujuba accessions. In addition, 'Ilbon' could produce intact seeds and seed productivity of 'Ilbon' was highest compared with major Z. jujuba accessions. Principal component analysis and clustering analysis using the morphological characteristics of Z. jujuba accessions have been classified them to geographical origin. In particular, 'Ilbon' was clearly distinguished from the major Z. jujuba accessions. Therefore, 'Ilbon', which has the highest seed productivity and functional component, will be used as a material for cross breeding and will promote genetic study of Z. jujuba.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.802-809
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• 2010

Phytophthora blight of pepper is the most economically important disease in the world cultivation regions. We investigated the phytophthora blight resistance of 300 accessions of Korean landrace of hot pepper germplasms collected from 83 local regions. The disease incidence rate was checked from 7 days to 28 days at an interval of 7 days after inoculation under greenhouse conditions. Among 300 accessions, the disease incidence rate of phytophthora blight of 67 accessions of pepper germplasm was more than 60.1%, while no disease was observed in 37 accessions at 7 days after inoculation. At 28 days after inoculation, five and eleven accessions of pepper germplasm were resistance and moderate resistance to $P.$ $capsici$, respectively. Two hundred forty four susceptible accessions (81.3%) of pepper were scored as having more than 60.1% of disease incidence of phytophthora blight. This result suggests that five candidate pepper germplasm might be used as breeding resources for the phytophthora blight resistance breeding program. Also, further genetic studies should be carried out to verify this result, with the overall focus of providing information on important characteristics of pepper germplasm.

• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.444-454
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• 2013

The development of random amplified polymorphic DNA (RAPD) and expressed sequence tag-derived simple sequence repeats (EST-SSRs) provided a useful tool for investigating Korean ginseng genetic diversity. In this study, 18 polymorphic markers (7 RAPD and 11 EST-SSR) selected to assess the genetic diversity in 31 ginseng accessions (11 Korean ginseng cultivars and 20 breeding lines). In RAPD analysis, a total of 53 unique polymorphic bands were obtained from ginseng accessions and number of amplicons ranged from 4 to 11 with a mean of 7.5 bands. Pair-wise genetic similarity coefficient (Nei) among all pairs of ginseng accessions varied from 0.01 to 0.32, with a mean of 0.11. On the basis of the resulting data, the 31 ginseng accessions were grouped into six clusters. As a result of EST-SSR analysis, 11 EST-SSR markers detected polymorphisms among the 31 ginseng accessions and revealed 49 alleles with a mean of 4.45 alleles per primer. The polymorphism information content (PIC) value ranged from 0.06 to 0.31, with an average of 0.198. The 31 ginseng accessions were classified into five groups by cluster analysis based on Nei's genetic distances. Consequently, the results of ginseng-specific RAPD and EST-SSR markers may prove useful for the evaluation of genetic diversity and discrimination of Korean ginseng cultivars and breeding lines.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.28-35
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• 2008

Eleven accessions of Hedera helix, three accessions of Hedera rhombea, one accession of Fatshedera lizei, and one accession of Fatsia japonica were collected and their genetic diversity was measured by using 10 RAPD primers. Approximately ninety seven percentage of polymorphism was detected, because broad germplasm, three genus, was used. Total 97 bands were scored and a dendrogram was constructed by using an UPGMA method. Accessions belonging to Hedera helix tightly clustered in one group: eight accessions showed extremely narrow genetic differences and the other three accessions also showed significant similarity. Despite of their genetic similarity, they showed morphological variations. The morphological variation with a narrow genetic differences indicated that the ivy cultivars have been indeed developed from a mutation breeding program. Genetically most unrelated Fatsia japonica showed a genetic distance of 0.63 on the average between other species. An accession from Fatshedera lizei developed by crossing between two genus, Hedera helix and Fatsia japonica, was allocated together with accessions from Hedera rhombea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.64-64
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• 2019

Screening and identification of genetic resources based on their phytoconstituents and morphological characters potentially provide baseline data for researchers, breeders, and nutraceutical companies who wish to formulate a nutrient-dense diet and health beneficial supplement. Thus, we evaluated the amount of total phenolic content and major phenolic compounds; examined if phenolic compounds could be used as distinguishing factors for perilla genetic resources; and investigated the relation between some quantitative and qualitative morphological characters with the contents of phenolic compounds in 360 accessions obtained from National Agrobiodiversity Center gene bank, Jeonju, Korea. Total phenolic content (TPC) was estimated using Folin-Ciocalteu colorimetric assay. Individual phenolic compounds were determined using an Ultra-High Performance Liquid Chromatography system equipped with Photodiode Array detector. Considerable variations were observed in TPC (7.99 to 117.47 mg GAE/g DE), rosmarinic acid (RA) (ND to 19.19 mg/g DE), caffeic acid (CA) (ND to 0.72 mg/g DE), apigenin-7-O-diglucuronide (ADG) (ND to 1.24 mg luteolin equivalent (LUE)/g DE), scutellarein-7-O-glucuronide (SG) (ND to 4.32 mg LUE/g DE), and apigenin-7-O-glucuronide (AG) (ND to 1.60 mg LUE/g DE). RA was the most dominant phenolic compound in most accessions (95.3%) followed by SG. The adaxial leaf color was light green, green and dark green in 13.8%, 65.0%, and 21.1 % of the accessions, respectively. 78.8% of the accessions had light green color at the abaxial side with the remaining being described as green. Most of the accessions (96.9%) were cordate shape, the remaining being eclipse. Intensities of green pigment at abaxial and adaxial leaf surfaces were correlated with contents of individual phenolic compounds and TPC whereas leaf length and width had no correlation with TPC, CA and RA, and negatively correlated with ADG, AG, and SG. Leaf shape was not related with content of phenolic compounds, color of leaves, or the length or width of leaves. Accessions IT57426, IT157434, IT267710, and IT267712 which contained relatively high contents of TPC and major phenolic compounds (RA and SG) could be used for further research in breeding and bioassay test. Our study result showed the contents of total phenolics and individual phenolic compounds along with the morphological characters could be useful distinguishing factors for perilla genetic resources.

• Korean Journal of Plant Resources
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• v.25 no.6
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• pp.762-772
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• 2012

The objective of this study was to analyze the genetic diversity using SSR marker and investigate the fatty acid composition of perilla (P. frutescens var. frutescens) germplasm. Genetic diversity among 95 accessions, which consisted of 29 weedy types and 66 landrace accessions, was evaluated based on 12 SSR markers carrying 91 alleles. The mean values of observed ($H_O$) and expected heterozygosities ($H_E$) were 0.574 and 0.640, respectively, indicating a considerable amount of polymorphism within this collection. A genetic distance-based phylogeny grouped into two distinct groups, which were the landrace, moderate and weedy type, genetic distance (GD) value was 0.609. The physicochemical traits about crude oil contents and fatty acid compositions were analyzed using GC. Among tested germplasm, the total average oil contents (%) showed a range from 28.57 to 49.67 %. Five fatty acids and their contents in the crude oils are as follows: ${\alpha}$-linolenic acid (41.12%-51.81%), linoleic acid (15.38%-16.43%), oleic acid (18.93%-27.28%), stearic acid (2.56%-4.01%), and palmitic acid (7.38%-10.77%). The average oil content of wild types was lower than landrace, and the oil content of middle genotype accessions was higher than other germplasm, but no significant variation between landrace and wild types was shown. Nevertheless, IT117174, landrace of Korea, was highest in crude oil content (47.11%) and linolenic acid composition (64.58%) among the used germplasm. These traits of the selected accessions will be helped for new functional plant breeding in perilla crop.

• Journal of Life Science
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• v.14 no.3
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• pp.425-428
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• 2004

Molecular authentication and genetic polymorphism of Korean ginseng cultivars and accessions were investigated using ISSR (inter-simple sequence repeat amplification) markers. Five primers among 56 produced clear and reproducible DNA fragments among seven cultivars and accessions. A total of 43 bands ranging from 250 bp to 1,700 bp from five primers were scored. Average number of bands per primer was 8.6 and only nine bands were polymorphic across the six Panax ginseng from Korea. Especially Chunpoong cultivar exhibited the highest level of polymorphism, whereas other accessions did not showed almost any polymorphism. Consequently, these ISSR markers will be available to differentiate Chunpoong cultivar from other major Korean ginseng cultivars and accessions, such as Yunpoong, Hwangsukjong and Jakyungjong, at the DNA level.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.389-396
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• 2012

Melon (Cucumis melo) is an annual herbaceous plant of the family Cucurbitaceae. Phytophthora rot, caused by Phytophthora capsici is a serious threat to cucurbits crops production as it directly infects the host plant, and it is difficult to control because of variable pathogenicity. This study investigated the resistance of 450 accessions of melon germplasm against Phytophthora rot by inoculating the seedlings with sporangial suspension ($10^{5\;or\;6}$ zoosporangia/ml) of P. capsici. Disease incidence of Phytophthora rot was observed on the melon germplasm at 7-day intervals for 35 days after inoculation. Susceptible melon germplasm showed either severe symptoms of stem and root rot or death of the whole plant. Twenty out of 450 tested accessions showed less than 20% disease incidence, of which five accessions showed a high level of resistance against Phytopthtora rot. Five resistant accessions, namely IT119813, IT138016, IT174911, IT174927, and IT906998, scored 0% disease incidence under high inoculum density of P. capsici ($10^6$ zoosporangia/mL). We recommend that these candidate melon germplasm may be used as genetic resources in the breeding of melon varieties resistant to Phytophthora rot.