• Horticultural Science & Technology
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• v.32 no.2
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• pp.235-240
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• 2014

Cucumber mosaic virus (CMV) is one of the most important viral diseases in pepper (Capsicum annuum L.), and several genes for resistance were reported in Capsicum spp. In Korea, a single dominant gene that is resistant to $CMV_{Fny}$ and $CMV_{P0}$ has been used for breeding. Recently, a new strain ($CMV_{P1}$) was reported that could infect cultivars resistant to both $CMV_{Fny}$ and $CMV_{P0}$. Therefore, breeding of more robust CMV-resistant cultivars is required. In this study, we surveyed the inheritance of $CMV_{P1}$ resistance and analyzed the location of the resistance loci. After $CMV_{P1}$ inoculation of various germplasms and breeding lines, one accession (ICPN18-8) showed no visual symptoms at 15 dpi (days post inoculation) but was susceptible after 45 dpi, and one resistant line (I7339) showed resistance until at 45 dpi. The latter line was used for tests of resistance inheritance. A total of 189 $F_2$ plants were examined, with 42 individuals showing resistance at 15 dpi and a phenotype segregation ratio close to 1:3 (resistant:susceptible plants). In a lateral ELISA test at 45 dpi, 11 plants showed resistance, and the segregation ratio was changed to 1:15. These results indicate that resistance in C. annuum 'I7339' is controlled by two different recessive genes; we named these resistance genes 'cmr3E' and 'cmr3L,' respectively. To locate these two resistant loci in the pepper linkage map, various RAPD, SSR, and STS markers were screened; only nine markers were grouped into one linkage group (LG). Only one RAPD primer (OPAT16) was distantly linked with cmr3E (22.3 cM) and cmr3L (20.7 cM). To develop more accurate markers for marker-assisted breeding, enriching for molecular markers spanning two loci will be required.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.99-99
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• 2017

Chili pepper (Capsicum annum) is origin of subtropical region, and has been spread all over the world. It is increasing the production and consumption in recent year. Chili peppers are readily incorporated into local South Asian cuisines perhaps because people are already familiar with pungent and spicy flavors. Chili peppers, despite their fiery "hotness", are one of very popular spices known for their medicinal and health benefiting properties. Especially in South East Asia, they grow up so many cultivars of them recently, so it is so important crop world wide. In South East Asia, there are some articles about chili pepper in Thailand and Indonesia, but in Vietnam there is not so much information about chili pepper. In this paper, we analyzed genetic diversity in Vietnamese Chili pepper through the survey of local chili pepper. As a result, we got 38 kinds of chili fruits, 26 kinds of leaves and some information from farmers all in Vietnam. And I made the phylogenetic tree by SSR with 10 DNA markers. Finally we found the genetic similarities by regions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.239-247
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• 2006

This study was carried out to investigate polymorphism, gene diversity, and geographical relationships of 81 Korean wild (Glycine soja) and 130 cultivated soybeans (G. max) using seven simple sequence repeat (SSR) markers. A total of 144 alleles were observed in 211 accessions with an average of 20.6. Each SSR loci showed 13 (Satt532) to 41 (Sat_074) multialleles. The range of alleles within the loci was wider in wild soybean than the cultivated soybeans. The average genetic diversity values were 0.88 and 0.69 in wild and cultivated soybeans, respectively. In a scatter diagram of wild and cultivated soybeans based on canonical discriminant analysis, CAN1 accounted for 84.2% while CAN2 did 8.5%. Two species were grouped into three: group I (G. max), group II (G. soja), and group III (complex of G. max and G. soja). The geographical relationships of wild soybean were distinguished into two groups: Gyeonggi for Group I, and Gyeongsang, Jeolla, Gangwon, and Chungcheong for Group II. Those of cultivated soybeans were distinguished into Gyeonggi, Gangwon, and Gyeongsang for Group I, and Jeolla and Chungcheong for Group II. Therefore, the geographical relationships of wild soybeans were well typified based on the ecosystems of the Korean peninsula.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.525-533
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• 2010

In this study, random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) analyses were utilized for evaluation of genetic diversity of 34 Korean bred and introduced apple cultivars. Thirty-seven RAPD primers detected a total of 193 polymorphic bands (36.2%) with an average of 5.6. Twenty-six SSR markers generated a total of 112 alleles with an average 4.3 alleles per locus. Genetic diversity of 34 cultivars estimated by polymorphic information content (PIC) value ranged from 0.536 (CH03d12) to 0.952 (CH04c06) with an average of 0.843. By UPGMA (unweighted pair-group method arithmetic average) cluster analysis with 305 polymorphic bands, the apple cultivars were classified four groups by similarity index of 0.640. The 'Seokwang' was included in group I. Group II consisted of 12 cultivars which have 'Golden Delicious' in their pedigree, with the exception of 'Spur Earliblaze' and 'Jonathan'. Group III included 13 cultivars which have usually 'Fuji' in their ancestry and bud sport of 'Fuji' cultivars. Group IV consisted of 8 cultivars with 'Hongro', 'Gamhong', and 'Saenara'. Similarity values among the tested apple cultivars ranged from 0.529 to 0.987, and the average similarity value was 0.647. The similarity index was the highest (0.987) between 'Hwarang' and 'Danhong', and the lowest (0.529) between 'Seokwang' and 'Hwarang'. The genetic relationships among the 34 studied apple cultivars were basically consistent with the known pedigree.

• Journal of Life Science
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• v.14 no.5
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• pp.821-828
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• 2004

The increasing apparent photosynthetic rate per leaf area may improve seed yield in soybean. Leaf area, length and width are related to the photosynthetic capability of the plant. In this study, two populations derived from the cross of Keunolkong, Shinpaldalkong and Iksanl0 were evaluated with simple sequence repeat (SSR) markers to identify length, width and length/width ratio of leaf. Leaf length/width ratio were significantly negative correlation with leaf width in K/S and K/I populations. In the K/S population, two minor QTLs for leaf length (LL) were found on LG Dlb+W and 1. Two QTLs on LG J and L were related to LL in K/I population. Two and three minor QTLs were identified in leaf width with total phenotypic variation of 13% and 18.04 in K/S and K/I populations, respectively. The leaf length/width ratio, two QTLs on LG I and L, and three QTLs on LG Cl, E and L were related to K/S and K/I populations, respectively. Thus it is assumed that the leaf traits are very much dependent on the genotype used and different breeding approach should be considered for the selection of favorite leaf traits in soybean breeding programs.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.667-675
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• 2007

The genetic diversity and the spatial structure in two populations of Abelia tyaihyoni in Yeongwol region were studied by employing I-SSR markers. In spite of the limited distribution and small population sizes of Abelia tyaihyoni, the amount of genetic diversity estimated at the individual level was comparable to other shrub species (S.I.=0.336, h=0.217). Genetic diversity at the genet level was very similar to that at individual level. (S.l.=0.339, h=0.219). About 18.7 percent of total variation was allocated between two populations, which was slightly higher or similar level as compared with other shrub species. Genotypic diversity estimated by the ratio of the number of genets ($N_G$) over the total number of individuals (N) and a modified Simpson's index ($D_G$) were also higher than those of other shrubs. The maximum diameter of a genet did not exceed 5.5 m. The high level of gene and genotypic diversity, and the relatively limited maximum diameter of a genet suggested that the clonal propagation is not the most dominant factor in determining the population structure of Abelia tyaihyoni. Spatial autocorrelation analysis revealed significant spatial genetic structure within 12 m and 18 m distances in two populations A and B, respectively. Autocorrelations among individuals at the both individual and genet levels in each population didn't show any considerable differences. As a sampling strategy for ex-situ conservation of populations showing continuous distribution, a minimum distance of 18 m between individuals was recommended. For the populations with many segments, it was considered very crucial to sample materials from as many segments as possible.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.57-57
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• 2017

Chrysanthemum is one of the most important floral crop in Korea produced about 7 billion dollars (1 billion for pot and 6 billion for cutting) in 2013. However, it is difficult to breed and to do genetic study because 1) it is highly self-incompatible, 2) it is outcrossing crop having heterozygotes, and 3) commercial cultvars are hexaploid (2n = 6x = 54). Although low-density genetic map and QTL study were reported, it is not enough to apply for the marker assisted selection and other genetic studies. Therefore, we are trying to make high-density genetic mapping using GBS with about 100 $F_1s$ of C. boreale that is oHohhfd diploid (2n = 2x = 18, about 2.8Gb) instead of commercial culitvars. Since Chrysanthemum is outcrossing, two-way pseudo-testcross model would be used to construct genetic map. Also, genotype-by-sequencing (GBS) would be utilized to generate sufficient number of markers and to maximize genomic representation in a cost effective manner. Those completed sequences would be analyzed with TASSEL-GBS pipeline. In order to reduce sequence error, only first 64 sequences, which have almost zero percent error, would be incorporated in the pipeline for the analysis. In addition, to reduce errors that is common in heterozygotes crops caused by low coverage, two rare cutters (NsiI and MseI) were used to increase sequence depth. Maskov algorithm would also used to deal with missing data. Further, sparsely placed markers on the physical map would be used as anchors to overcome problems caused by low coverage. For this purpose, were generated from transcriptome of Chrysanthemum using MISA program. Among those, 10 simple sequence repeat (SSR) markers, which are evenly distributed along each chromosome and polymorphic between two parents, would be selected.

• Journal of Forest and Environmental Science
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• v.24 no.1
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• pp.27-34
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• 2008

Level and distribution of genetic diversity in seven populations of Albizia lucida Benth. in eastern region of the Indian sub-continent were estimated using ISSR markers. Relatively higher level of genetic diversity within populations was observed in seven populations of A. lucida (mean of 0.38). From the result of AMOVA, majority of genetic diversity was allocated within populations (96.2%) resulting in a moderate degree of population differentiation. The observed distribution pattern of I-SSR variant among the populations was coincided with the typical pattern of long-lived woody tree species. Genetic relationships among the populations, reconstructed by UPGMA method, revealed two genetic groups. The population of Anugul and Bargarh turned out to be the most closely related despite a distance location between them. These formations will be of great value in the development of conservation plans for species exhibiting high levels of genetic differentiation due to fragmentation, such as indication of conservation unit size, which populations should be chosen as priority in conservation plans and which samples should be introduced in areas with a low number of individuals of A. lucida.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.155-160
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• 2001

Changes in genetic diversity after seed-tree practice were simulated in test plantation of tulip tree at Sokdal-ri, Banwol-myon, Hwasung-gun, Kyungki Provence. I-SSR markers were analyzed in a total of 305 tulip trees. A total of 89 amplicon variants were observed by PCR with 9 I-SSR primers. Genetic diversity for 305 trees was relatively high (S. I. =0.4532). Individuals originated from the seed orchards in U.S.A. showed the highest level of genetic diversity (0.4530), those from Anyang showed the medium level (0.4152), and those from Cheonbuk showed the lowest (0.3929). Simulation of seed-tree practice accompanied by 2 consecutive thinnings was performed on the basis of morphological characteristics and planted distances of the individual trees, which left 37 trees as candidates for seed-trees. Decreasing rate of genetic diversity within seed sources was greatest for individuals from Cheonbuk (28.3%), moderate for those from Anyang (16.3%), and smallest for those from U.S.A. (8.0%). In spite of little difference in decreasing rate of individuals for the 3 seed sources (87.5~88.2%), large difference in decreasing rate of genetic diversity within seed sources might be due to difference in number of mother trees for the 3 seed sources. For example, whereas individuals originated from the seed orchard in U.S.A., which showed the smallest decreasing rate of genetic diversity, might be originated from relatively large number of mother trees, those from Anyang and Cheonbuk might be originated from relatively small number of mother trees. Although mean of 17.5% of the genetic diversity within seed sources was decreased through 2 consecutive thinnings, a decrease in genetic diversity for the whole individuals (37 trees) was only 6.1%. This observation suggests that the seed-tree practice on the basis of the criteria established in the present study may not result in great reduction in overall genetic diversity of the progenies.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.248-258
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• 2006

Genetic diversity of 91 Korean soybean cultivars was assessed with 20 simple sequence repeat (SSR). Twenty SSR loci generated a total of 149 alleles. The number of alleles for each SSR locus ranged from 3 to 15 with a mean of 7.5 alleles. Genetic diversity estimated by PIC value of 91 cultivars was ranged from 0.424 to 0.905 with an average of 0.711. Cluster analysis based on Nei's genetic distances classified 91 soybean cultivars except Geomjeongkong 4 into 7 groups. The majority groups were I, IV, and VI which included 26, 24, and 18 cultivars, respectively. Obvious differences in genetic diversity appeared to be related with the released periods of cultivars and utilization type of cultivars, but not with breeding sites. Cultivars released in 1970's and in 1990's showed the lowest and the highest genetic diversities with 0.576 and 0.706, respectively. Soybean cultivars for vegetable and early maturity showed the lowest genetic diversity with 0.514, while those for soy sauce and tofu showed the highest genetic diversity with 0.691. Genetic distance between soybean cultivar groups developed before 1969 and during 1970's was the nearest, while genetic distance between those developed in 1970's and 1990's was the furthest. Cultivar group for vegetable and early maturity showed the furthest genetic distance with cultivar group for soy sauce and tofu, while it showed the nearest genetic distance with cultivar group for cooking with rice. Genetic distance was greater between soybean cultivar groups developed in Suwon and Iksan than between those developed in Milyang and Iksan.