• Horticultural Science & Technology
• /
• v.31 no.5
• /
• pp.580-589
• /
• 2013

This study was carried out to evaluate the suitability of microsatellite markers for varietal identification and genetic relationship of 170 commercial pepper cultivars. The relationship between marker genotypes and 11 pepper cultivars with different morphological traits was also analyzed. Of the 302 pairs of microsatellite primers screened against 11 pepper cultivars, 24 pairs were highly polymorphic in terms of number of alleles. These markers were applied for the construction of DNA profile data base for 170 commercial pepper cultivars. A total of 164 polymorphic amplified fragments were obtained from 24 microsatellite primers. The average polymorphism information content was 0.673 ranging from 0.324 to 0.824. One hundred and sixty four microsatellite alleles were used to calculate Jaccard's distance coefficients using unweighted pair group method. A clustering group of varieties, based on the results of microsatellite analysis, were categorized into 3 major groups corresponding to morphological traits. The phenogram discriminated all varieties by markers genotypes. These microsatellite markers will be useful as a tool for protection of plant breeders' intellectual property rights through variety identification in distinctness, uniformity and stability test.

• The Korean Journal of Ecology
• /
• v.23 no.1
• /
• pp.17-23
• /
• 2000

The spatial distribution of allelic frequencies was studied in the natural population of three species (Ligustrum obtusiflolium, Alnus japonica, and Pinus densflora). The distributional patterns of the crown-cover centers were compared between two populations in forests. L. obtusifolium and p. densiflora showed a significantly positive spatial autocorrelation as measured by Moran's I. In P densiflora, the genetic similarity was shown by individuals within up to a scale of 18 m distance and this is partly due to combination of pollen dispersal and long distance seed dispersal by wind or men. In L. obtusifolium, population structure in the distribution of allelic frequencies is related to mating systems and is consisted of a scale of 12.5 m intervals. No spatial structuring of allele frequencies was found for polymorphic enzyme loci within a natural population of Alnus japonica. The results also in- dicate that positive associations between L. obtusifolium and P densiflora can occur when both select the same habitat or have the same environmental requirements.

• Journal of Life Science
• /
• v.17 no.4 s.84
• /
• pp.455-461
• /
• 2007

Assessments of population genetic structure and diversity can be of value in formulating management plans for threatened eelgrass(Zostera maim). Using randomly amplified polymorphic DNA markers, we found evidence of significant genetic structure among the populations of eelgrass sampled at three areas(Geojedo, Gaedo, and Jedo). A highly isolated(>100 km apart) population from the Geojedo had a long genetic distance(0.16), whereas the populations from the Gaedo and Jedo(<10 km apart) exhibited far less distance(0.08). The analysis of similarity within population showed that Geojedo was over 70%, which was of lower value than of Gaedo and Jedo. Based on these results, we realized that heterogeneous population was in accordance with geographic separation. This is caused by limited seed dispersal and interrupted gene flow, although the sample size is small.

• Journal of Life Science
• /
• v.14 no.2
• /
• pp.345-350
• /
• 2004

The present study was investigated microgeographic variations to spatial autocorrelation in the Korean alder, Alnus hirsuta. Separate counts of each type of join (combination of genotypes at a single locus) for each allele, and for each distance class of separation, were tested for significant deviation from random expectations by calculating the Standard Normal Deviation (SND). Moran's I was significantly different from the expected value in 24 of 120 cases (20.0%). 17 of these values (14.2%) were significantly negative, indicating genetic dissimilarity among pairs of individuals in the ten distance classes. Many Korean populations of alder are small and are distributed by men for firewood. This occasional cutting of seed-bearing stems may bring a high level of gene flow. In addition, stump sprouting ability also may contribute to the fact that the Chengkwang population at Gijang is unusual in lacking spatial genetic structure.

• Journal of the Korean Society of Radiology
• /
• v.17 no.1
• /
• pp.149-156
• /
• 2023

The purpose of this study is to compare of growth and chlorophyl between old-barley seed (OBS, 2019) and New-barley seed (NBS, 2020) exposed by X-ray. After germination the OBS and NBS, experimental group was exposed by 30 Gy X-ray using linear accelerator (Clinac IS, VERIAN, USA), by 6 MV X-ray, SSD 100 cm, 18 × 10 cm², 600 MU/min. Length was measured every day until 9th day, and chlorophyl was analyzed using spectrophotometer(uv-1800, shimadzu, japan) after measuring weight in 9th day. Data analysis was performed the Independent T-test using SPSS ver 26.0(Chicago, IL, USA). NBS grow more faster than OBS in control group, but OBS grow more faster than NBS in experimental group. Length of control group was longer significantly every day than that of experimental group in OBS. NBS weighted more than OBS in control group, but OBS weighted more than NBS in experimental group. In comparing chlorophyl density, NBS high more than OBS in control group as well as experimental group. Growth and weight of OBS was effected more those than NBS by X-ray, but NBS in chlorophyl by X-ray. It is expected to be used as basic data for future X-ray research in barley seed.

• Journal of Korean Society of Forest Science
• /
• v.97 no.2
• /
• pp.144-151
• /
• 2008

Using 8 isozyme polymorphic loci as gene markers, we studied the spatial distribution of genotypes in a naturally regenerated uneven-aged Eastern Siberian Fir (Abies nephrolepis Max.) stand (1ha, $100{\times}100m$) on Mt. Ohdae in northeastern South Korea. Gregorius' distograms and Moran's I correlograms revealed no evidence of significant genetic structure at three spatial classes of 5 m, 10 m, and 20 m. Extensive gene flow, due to the long distance dispersal of pollen and seeds in A. nephrolepis, may account for the lack of fine-scale spatial structure. Alternatives would be overlapping seed shadows caused by high densities of A. nephrolepis adult trees (160 trees/ha) and/or intraspecific competition resulting in extensive thinning within maternal half-sib groups.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.12
• /
• pp.204-213
• /
• 1999

This paper suggests a numerical method of finding optimal geometric path and minimum-time motion for a manipulator arm. To find the minimum-time motion, the optimal geometric path is searched first, and the minimum-time motion is searched on this optimal path. In the algorithm finding optimal geometric path, the objective function is minimizing the combination of joint velocities, joint-jerks, and actuator forces as well as avoiding several static obstacles, where global search is performed by adjusting the seed points of the obstacle models. In the minimum-time algorithm, the traveling time is expressed by the linear combinations of finite-term quintic B-splines and the coefficients of the splines are obtained by nonlinear programming to minimize the total traveling time subject to the constraints of the velocity-dependent actuator forces. These two search algorithms are basically similar and their convergences are quite stable.

• Journal of Ecology and Environment
• /
• v.37 no.1
• /
• pp.21-29
• /
• 2014

Robinia pseudoacacia has become invasively naturalized in Japan. We investigated the role of sexual reproduction in the development of R. pseudoacacia riparian forests along the Chikumagawa River in Japan, by using five chloroplast (cpSSR) and seven nuclear (nSSR) markers. We identified eight chloroplast haplotypes and 147 nuclear genotypes from 619 R. pseudoacacia trees sampled in three plots (Plots A, B, and C) and along two line transects (Lines D and E). CpSSR analyses showed that multiple maternal lines were distributed along the river, and that some haplotypes from different populations overlapped. In addition, while Plots A and B were separated by a short distance, only these two plots exhibited genetic differentiation in the haplotypes. In the nSSR analysis, all pairwise $F_{ST}$ values among the three plots were significantly different from zero. Kinship analysis based on nSSR markers revealed that kinship connected many individuals to another individual from the same plot. These results indicate that seed dispersal near to mother trees contributes to the fine-scale genetic structure of R. pseudoacacia riparian forests. Our results indicate that sexual reproduction, in addition to asexual reproduction, is a major contributor to the fine-scale formation of R. pseudoacacia forests.

• Korean Journal of Plant Resources
• /
• v.20 no.6
• /
• pp.530-539
• /
• 2007

Genetic variation and structure of 9 subpopulations of Symplocarpus renifolius Schott ex Tzvelev on Mt. Cheonma, in Korea, were determined via starch-gel electrophoresis. The genetic diversity at 10 loci for 8 isozymes ($P_{99}=66%,\;A=2.26,\;H_o=0.212,\;H_e=0.230$) was found to be considerably higher than that seen in other long-lived perennial plants. On the whole, the genotype frequencies were in accordance with Hardy-Weinberg expectations. Approximately 5%($\theta=0.049$) of the total variability was among subpopulations. The high levels of observed genetic diversity in S. renifolius were attributed to a universal outcrossing system and other specific factors like differences in age classes and widely scattered individuals around the main distribution. Heterozygosity was highest at a mid-range of elevation($450m{\sim}600m$). The lowest heterozygosity at lower elevation was attributed to the possible origin of seeds transported by water from upstream regions during the monsoon season. Spatial structure in a subpopulation evidenced a strong autocorrelation between closer individuals within $3{\sim}4m$ of distance. This was assumed to be attributable to the restricted seed dispersal characteristics of S. renifolius. In accordance with the findings generated in this study, some implications regarding the conservation of S. renifolius at the Mt. Cheonma were also presented.

• Molecules and Cells
• /
• v.21 no.1
• /
• pp.135-140
• /
• 2006

Cytoplasmic male sterility (CMS) in plants, which is due to failure to produce functional pollen, is a maternally inherited trait. Specific nuclear genes that suppress CMS, termed fertility restorer (Rf) genes, have been identified in several plants. In this study, Rfl-inked molecular markers in pepper (Capsicum annuum L.) were detected by bulked segregant analysis of eight amplified fragment length polymorphisms (AFLPs). Only AFRF8 was successfully converted to a cleaved amplified polymorphic sequence (CAPS) marker. This was named AFRF8CAPS and genotype determination using it agreed with that obtained with the original AFRF8. A linkage map with a total size of 54.1 cM was constructed with AFRF8CAPS and the seven AFLP markers using the Kosambi function. The AFRF8CAPS marker was shown to be closest to Rf with a genetic distance of 1.8 cM. These markers will be useful for fast and reliable detection of restorer lines during $F_1$ hybrid seed production and breeding programs in pepper.