• Horticultural Science & Technology
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• v.16 no.1
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• pp.18-20
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• 1998

The present research was conducted to study genetic relationship and cultivar identification in sweet potato (lpomoea batatas) using RAPD method. Thirteen cultivars of sweet potato in Korea were classified by UPGMA clustering method into three groups as follows; group I was corresponded to 'Choongsung100'; group II, 'Eunmi', 'Saengmi', 'Suwon147' and 'Yulmi'; group III, 'Hongmi', 'Jinmi', 'Kwandong95', 'Seonmi', 'Wonmi', 'Shinyulmi', 'Jeungmi', and 'Poongmi'. Identification using RAPD was generally consistent with breeding pedigree of those parents. However, inconsistent results may be caused by clonal variation. The results presented in this study suggest that RAPDs in sweetpotato are likely to be useful for cultivar identification and various procedures in breeding. The use of various DNA marker system assists selection programs for economically important trait, and may facilitate selection in earlier growing stage. This systems may enhance the prospects for improving sweet potato cultivar by accurate marking desirable traits at DNA level.

• Korean Journal of Agricultural Science
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• v.43 no.2
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• pp.153-162
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• 2016

Chilli is a widely consumed crop throughout the world. However, chilli anthracnose is a major constraint in chilli production leading to huge economic losses worldwide. Colletotrichum is a large genus of Ascomycete fungi, containing species that cause anthracnose diseases on a wide range of crops of economic value. This review is aimed at critically and accurately examining the taxonomic identification of Colletotrichum species by morphological and molecular approaches as well as assessing their management options. The use of appropriate integrated management practices, such as cultural, mechanical, chemical, and biological control, are important in chilli anthracnose disease prevention and control. Emphasis is laid on the use of biological control because it is cost effective and eco-friendly, and is an appropriate approach for disease management. The use of resistant cultivars is the cheapest, easiest, safest, and most effective means of controlling crop diseases. But, since no resistant cultivars of chilli have been developed and commercialized, it is very important to develop biological management strategies. Further studies leading to integrated disease management strategies need to be carried out.

• Journal of Ginseng Research
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• v.41 no.1
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• pp.31-35
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• 2017

Background: Korean ginseng (Panax ginseng) is a well-known medicinal plant of Oriental medicine that is still in practice today. Until now, a total of 11 Korean ginseng cultivars with unique features to Korean ginseng have been developed based on the pure-line-selection method. Among them, a new cultivar namely G-1 with different agricultural traits related to yield and content of ginsenosides, was developed in 2012. Methods: The aim of this study was to distinguish the new ginseng cultivar G-1 by identifying the unique single-nucleotide polymorphism (SNP) at its 45S ribosomal DNA and Panax quinquefolius region than other Korean ginseng cultivars using multiplex amplification-refractory mutation system-polymerase chain reaction (ARMS-PCR). Results: A SNP at position of 45S ribosomal DNA region between G-1, P. quinquefolius, and the other Korean ginseng cultivars was identified. By designing modified allele-specific primers based on this site, we could specifically identified G-1 and P. quinquefolius via multiplex PCR. The unique primer for the SNP yielded an amplicon of size 449 bp in G-1 cultivar and P. quinquefolius. This study presents an effective method for the genetic identification of the G-1 cultivar and P. quinquefolius. Conclusion: The results from our study shows that this SNP-based approach to identify the G-1 cultivar will be a good way to distinguish accurately the G-1 cultivar and P. quinquefolius from other Korean ginseng cultivars using a SNP at 45S ribosomal DNA region.

• The Plant Pathology Journal
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• v.26 no.4
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• pp.306-312
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• 2010

The pathotypes of Cercospora beticola, causal agent of sugar beet leaf spot disease, were identified by application of pathogenicity test using 100 isolates obtained from the provinces with intensive sugar beet cultivation. For the identification of pathotypes, five sugar beet cultivars were used each with different resistance factors. Cultivar reactions were determined by inoculation of cultivars with the isolates under controlled conditions and measuring disease severity on the $15^{th}$ day according to the 1-9 KWS Scale. Based on the reactions of the five cultivars, a total of 15 pathotypes were detected. All employed sugar beet cultivars were resistant to Pathotype no:1 comprising most of the isolates. Genetic diversity of the causal agent was characterized by AFLP reaction. The products acquired at the end of AFLP reaction were detected by means of Beckman CEQ 8800 DNA Capillary Series Analysis and the results obtained were evaluated according to the similarity index UPGMA. For the genetic analysis of C. beticola isolates, 9874 polymorphic fragments of sizes between 100 and 500 bp were analysed which were generated by nine primers. The dendrogram derived from AFLP analysis depicted the existence of five different subgroups. The polymorphism rate among isolates was 91.13% and the dendrogram distribution of the pathotypes obtained by pathogenicity indicated that pathotypes were not discriminated and did not compose any groups.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.179-190
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• 2023

Grapevine downy mildew, caused by Plasmopara viticola, significantly damages vineyards and is one of the most devastating diseases affecting cultivated grapes worldwide. In this study, we characterized the phenotypic and molecular traits of 11 P. viticola isolates from four grape-growing regions in South Korea. Additionally, we investigated the diversity of pathogenicity among these isolates and conducted an assay to evaluate the response of grape cultivars to P. viticola infection. Lemon-shaped sporangia were identified in the collected isolates, which released zoospores into the suspension at room temperature. Within a few hours of inoculation, the zoospores developed germ tubes. We tested 11 P. viticola isolates for pathogenicity in 845 grape cultivars to screen for grape host resistance to downy mildew infection. Among the tested isolates, JN-9 showed the highest virulence. Grape cultivars displayed varying phenotypic reactions to P. viticola infection: approximately 7% were highly susceptible, 41% were susceptible, 20% were moderately susceptible, 8% were resistant, and 24% exhibited extreme resistance. Phylogenetic analysis based on four genomic regions (internal transcribed spacer 1 [ITS1], actin, beta-tubulin, and cytochrome c oxidase II) revealed a close evolutionary relationship among all the Korean isolates, forming a single monophyletic lineage. Notably, these isolates showed greater similarity to European isolates than to American isolates. This comprehensive study contributes to a deeper understanding of the identity and behavior of P. viticola, which is crucial for developing effective resistance strategies against this pathogen in grape cultivars cultivated in South Korea.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.372-378
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• 2017

For comparison of the transcription profiles in apple (Malus domestica L.) cultivars differing in flesh color expression, two cDNA libraries were constructed. Differences in gene expression between red flesh apple cultivar, 'Redfield' and white flesh apple cultivar, 'Granny Smith' were investigated by next-generation sequencing (NGS). Expressed sequence tag (EST) of clones from the red flesh apple cultivar and white flesh apple cultivar were selected for nucleotide sequence determination and homology searches. High resolution melting (HRM) technique measures temperature induced strand separation of short PCR amplicons, and is able to detect variation as small as one base difference between red flesh apple cultivars and white flesh apple cultivars. We applied high resolution melting (HRM) analysis to discover single nucleotide polymorphisms (SNP) based on the predicted SNP information derived from the apple EST database. All 103 pairs of SNPs were discriminated, and the HRM profiles of amplicons were established. Putative SNPs were screened from the apple EST contigs by HRM analysis displayed specific difference between 10 red flesh apple cultivars and 11 white flesh apple cultivars. In this study, we report an efficient method to develop SNP markers from an EST database with HRM analysis in apple. These SNP markers could be useful for apple marker assisted breeding and provide a good reference for relevant research on molecular mechanisms of color variation in apple cultivars.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.303-311
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• 2019

Various colors of fruit skin and flesh are the most popular commercial criteria for peach classification. In order to breed new red-fleshed peach cultivar, many cross seedlings and generations should be maintained. Therefore it is necessary to develop early selection markers to screen seedlings with target traits to increase breeding efficiency. For the comparison of transcription profiles in peach cultivars differing in flesh color expression, two cDNA libraries were constructed. Differences in gene expression between red-fleshed peach cultivar, 'Josanghyeoldo' and white-fleshed peach cultivar, 'Mibaekdo' were analyzed by next-generation sequencing (NGS). Expressed sequence tag (EST) of clones from the two cultivars were selected for nucleotide sequence determination and homology searches. Putative single nucleotide polymorphisms (SNP) were screened from peach EST contigs by high resolution melting (HRM) analysis displayed specific difference between 8 red-fleshed peach cultivars and 24 white-fleshed peach cultivars. All 72 pairs of SNPs were discriminated and the HRM profiles of amplicons were established. In the study reported here, the development of SNP markers for distinguishing between red and white fleshed peach cultivars by HRM analysis offers the opportunity to use DNA markers. This SNP marker could be useful for peach marker assisted breeding and provide a good reference for relevant research on molecular mechanisms of color variation in peach cultivars.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.297-312
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• 2020

Wilted soybean plants were collected from soybeans cultivation fields in Korea from 2014 to 2016. Fusarium spp., Colletotrichum spp., Rhizoctonia spp., Macrophomina sp., Phytophthora spp., and Calonectria ilicicola were obtained from the infected samples. Out of these, Fusarium spp. were the dominant species (79.1%). In total, 53 isolates were identified as F. solani species complex, F. oxysporum species complex, F. graminearum species complex, and F. fujikuroi species complex based on mycological characteristics. Sequence typing analysis was conducted using translation elongation factor 1 alpha (TEF) to confirm the identification of isolates. All isolates were identified as F. solani, F. oxysporum, F. commune, F. asiaticum, and F. fujikuroi based on phylogenetic analysis of TEF sequences. Pathogenicity of 44 isolates was tested on three cultivars of soybean using the root dip inoculation method. Out of 5 Fusarium species, only F. asiaticum could not cause the symptoms or be weak. Ten isolates were selected based on pathogenic characters and species identification to investigate the host range and screen soybean cultivars for resistance. Fusarium solani, F. oxysporum, and F. commune were aggressive only to soybean, and F. fujikuroi was aggressive to kidney bean, yellow cowpea, black cowpea, adzuki bean as well as soybean. All 13 Korean soybean cultivars were susceptible to F. commune and F. fujikuroi. Out of 13 cultivars, cv. Janggi, cv. Poongsannamul, and cv. Socheongja were resistant to Fusarium wilt, while cv. Hwanggeumol and Chamol were susceptible to Fusarium wilt.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.231-240
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• 2009

A total of 26 Korean elite soybean cultivars including 21 certified cultivars was assessed to evaluate genetic diversity and to analyze relationship among them based on 15 SSR markers. Fifteen SSR markers generated a total of 201 alleles. Average number of alleles per SSR marker was 13.4 with a range from 8 to 19. Genetic diversity of 26 cultivars estimated by PIC value ranged from 0.782 to 0.931 with an average of 0.874. PIC value of Satt197 was the highest with 0.931 and Satt141 was the lowest with 0.782 among 15 SSR markers. Cluster analysis based on genetic distances classified 26 soybean cultivars into 3 clusters. Cluster I, II and III included 2, 7 and 17 cultivars, respectively. Average genetic diversity within clusters was 0.769 with a range from 0.720 to 0.799. Average genetic diversity between clusters was 0.813 with a range from 0.725 to 0.857. Genetic diversity was higher between clusters than within clusters. Genetic relationship among clusters was near between I and II, and I and III and far between II and III cluster. All of 26 Korean elite soybean cultivars could be identified by using any of 5 combinations of 2 SSR markers with higher PIC value, i.e, $Satt197+Sat_088$, Satt197+Satt245, $Sat_088+Sat_-036$, $Sat_088+Satt245$ and Satt185+Satt245.

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.212-213
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• 2011