Yong-Sham Kwon

Assessment of Genetic Variation among Commercial Tomato (Solanum lycopersicum L.) Varieties Using SSR Markers and Morphological Characteristics

Simple sequence repeats (SSR) is one of the most suitable markers for variety identification as it has great discrimination power for varieties with limited genetic variation. Genetic characterization of commercial tomato varieties was investigated using 33 SSR markers and 22 morphological traits. Thirty three SSR primer pairs were screened for 63 tomato varieties. A total of 132 polymorphic amplified fragments were obtained by using 33 SSR markers. The average polymorphism information content (PIC) was 0.628 ranging from 0.210 to 0.880. One hundred thirty two SSR loci were used to calculate Jaccards distance coefficients for UPGMA cluster analysis. A clustering group of varieties, based on the results of SSR analysis, were categorized into cherry and classic fruit type varieties. Almost all of the varieties were discriminated by SSR marker genotypes. The relationship between morphological and molecular data for 33 varieties out of 63 varieties was analyzed using Mantel matrix correspondence test. The correlation value between two methods was 0.644. However, SSR based dendrogram topology showed some similar form with morphological traits at the two main groups. Therefore, these markers may be used wide range of practical application in variety identification and pre-screening for distinctiveness test of tomato varieties.

DNA profiling of commercial pumpkin cultivars using simple sequence repeat polymorphisms

Pumpkin (Cucurbita spp.) is a major vegetable crop grown worldwide. Three species, C. pepo, C. moschata, and C. maxima, are economically important cultivated pumpkins. To develop a core set of markers for DNA profiling and cultivar identification, we used a total of 300 SSRs consisting of 158 CMTp and 142 CMTm that were previously identified in C. pepo and C. moshata, respectively. Polymorphisms in these primers were tested using a subset of 22 cultivars selected from a collection of 160 commercial cultivars. A total of 12 CMTp and 28 CMTm markers were selected based on polymorphism and number of alleles, and these 40 markers were used to genotype all 160 cultivars. Of these, 29 markers (5 CMTp and 24 CMTm) accurately detected a total of 215 alleles with an average of 7.41 alleles per marker in our collection of pumpkin cultivars. Their PIC values ranged from 0.327 to 0.894 with an average of 0.674. Analysis of genetic similarity using the 29 SSR markers revealed that the 160 cultivars were divided into five major clusters representing C. maxima×C. moshata hybrids (cluster I), C. moshata (cluster II), C. maxima (cluster III), C. pepo (cluster IV), and C. ficifolia (cluster V). In clusters I-IV, the cultivars were further separated into 2-3 sub-clusters. In addition, we found that 29 SSR markers were able to differentiate all 160 cultivars. Results from our study will facilitate genetic study and protection of breeders’ intellectual property rights in pumpkins.

Identification of Rice Variety Using Simple Sequence Repeat (SSR) Marker

SSR markers를 이용하여 벼의 품종간 유전적 유연관계 분석과 품종식별 방법에 대한 연구를 수행하여 얻어진 결과를 요약하면 다음과 같다. SSR primer 50개와 벼 보급종 21품종을 PCR 반응시킨 결과 다형성을 뚜렷하게 나타내는 primer는 23개였으며, 각 marker에 의해 발생된 대립유전자의 수는

Genetic Diversity of Wild Pear Accessions Collected in Korea

2{\sim}9

Development of Doubled-haploid Population and Construction of Genetic Map Using SSR Markers in Rice

까지 검출되었고, 평균값은 3.00개로 나타났다. 유전적 다형성 정도를 나타내어 주는 SSR marker의 PIC 값은 최소 0.091에서부터 최대 0.839까지 다양하게 분석되었다. SSR marker를 이용하여 분석된 벼 21품종에 대한 전체 유전적 유사도는

Analysis of Genetic Relationship of Apple Varieties using Microsatellite Markers

0.59{\sim}0.92

Use of SSR markers to complement tests of distinctiveness, uniformity, and stability (DUS) of pepper (Capsicum annuum L.) varieties.

의 범위에 속하였고 유사도 지수 0.65를 기준으로 할 때 4개의 그룹으로 구분되었다. SSR marker중에서 RM206, RM225, RM418, RM478은 marker genotype에 의해 21 품종에 대해 각각 고유한 밴드 특성을 나타내어 품종판별이 가능한 것으로 나타났다. 금후 이 연구결과는 벼 보급종의 품종식별을 위해 효과적으로 이용될 수 있는 것으로 나타났다. 【The objective of this study was carried out to evaluate the suitability of simple sequence repeat (SSR) markers for genetic diversity assessment and identification of rice varieties. The 23 primers selected from 50 SSR primers showed polymorphisms in the 21 rice varieties. The 2 to 9 SSR alleles were detected for each locus with an average of 3.00 alleles per locus. The polymorphism information content (PIC) ranged form 0.091 to 0.839. Based on band patterns, UPGMA cluster analysis was conducted. These varieties were separate into 4 groups corresponding to rice ecotype and pedigree information and genetic distance of cluster ranging from 0.59 to 0.92. The 4 SSR primer sets (RM206, RM225, RM418, RM478) selected form 23 polymorphic primers were differentiated all the rice variety from each other by markers genotypes. These markers may be used wide range of practical application in variety identification of rice.】

QTL mapping and molecular marker analysis for the resistance of rice to ozone.

The objective of this study was carried out to assess genetic diversity of Korean local accessions of wild pear using morphological traits and microsatellite markers. Assessment of 14 phenotypic traits showed high variation among wild pear accessions. These parameters were not applicable genetic diversity analysis of wild pear collection due to quantitatively inherit and their expression is affected by environmental factors. Microsatellite markers were used to evaluate the genetic similarity of 62 accessions. Among 50 tested SSR markers, 16 primer pairs were selected to profile genetic diversity on the basis of high level polymorphism. These microsatellite markers showed 1 or 2 discrete amplified fragment for all of the accessions. The sixteen microsatellite loci amplified 278 alleles, with 10 to 27 alleles (average 17.385) per locus. The mean of observed heterozygosity and polymorphism information content were 0.776 and 0.836, respectively. The Jaccard’s similarity coefficient ranged from 0.09 to 1.00. Two major groups were produced from all the accessions by UPGMA cluster analysis. Fifty five accessions could be discriminated except for 2 pairs. These results would be provided useful information about valuable genetic resources though assessment of genetic diversity and relationship in local pear accessions.

Marker-assisted introgression of quantitative trait loci associated with plant regeneration ability in anther culture of Rice (Oryza sativa L.).

A doubled-haploid (DH) population was developed through anther culture of F plants obtained from a cross between a japonica cultivar, `Nagdongbyeo`, as male parent and a indica cultivar, `Samgangbyeo`, as female parent. Segregation modes for plant length, culm length, panicle length, third internode length, and days to heading in the DH lines showed nearly normal distribution with wide range of variation. A molecular map with 136 simple sequence repeat (SSR) markers was constructed using the DH population. The total map distance was 1,909 cM and the average interval of marker distance was 14 cM.

Construction of a DNA profile database for commercial cucumber (Cucumis sativus L.) cultivars using microsatellite marker.

The objective of this study was to evaluate the suitability of microsatellite markers for variety identification in 42 apple varieties. For microsatellite analysis, 305 primer pairs were screened in 8 varieties and twenty six primer pairs showed polymorphism with clear band pattern and repetitive reproducibility. A total of 165 polymorphic amplified fragments were obtained in 42 varieties using 26 markers. Two to twelve alleles were detected for each locus with an average of 6.4 alleles per locus. A value of polymorphism information content (PIC) ranged from 0.461 to 0.849 with an average of 0.665. A total of 165 marker loci were used to calculate Jaccard`s distance coefficients using unweighted pair-group method with arithmetical average (UPGMA) cluster analysis. Genetic distance of cluster ranged from 0.27 to 1.00. Analysis of genetic relationship revealed that these 26 microsatellite marker sets discriminated a total of 41 varieties except for 1 variety among 42 varieties. These markers will be utilized as molecular data in variety identification of apple.