• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.933-943
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• 1994

The present study was undertaken to determine the effect of tensile force on DNA and protein biosynthesis in bone cells, and to identify the cell type(s) which primarily respond to external physical force among the heterogenous bone cell populations. As a prerequisite for this study, two bone cell populations which retain fibroblastic and osteoblastic feature were isolated from fetal rat calvaria with sequential enzyme digestion scheme. Tensile force was delivered to each bone cell population by two acrylic resin plates connected with a orthodontic expansion screw during culture period. Rate of DNA and protein synthesis in each bone cell population were assessed by the incorporated radioactivity of $[^3H]-thymidine$ into DNA and $[^3H]-proline$ into fraction of collagenase-digestible protein and noncollagenous protein, respectively. DNA synthesis of osteoblast-like calvarial cell populations was increased significantly by the application of tensile force for 24 hours. In contrast, no alteration in DNA synthesis of fibroblast-like populations could be observed in response to applied force. Tensile force induced the change in protein synthesis of bone cell populations with the same pattern. Total protein and collagen synthesis were increased whithin 24 hours in osteoblast-like populations, but not in fibroblast-like populations by tensile force application. These findings indicate that physical force can affect cellullar activity of the particular cell population, not all cell Populations residing in bone and osteoblasts respond more sensitively than fibroblasts. So osteoblasts can modulate the behavior of other bone cells including osteoclasts by producing several local regulating factors of bone metabolism. In this context, preferential responsiveness of osteoblasts to applied tensile force observed in this study suggests that osteoblasts may play an important role in regulation of physical force-induced remodelling process.

• Journal of Forest and Environmental Science
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• v.30 no.3
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• pp.285-292
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• 2014

Essential oil yields and chemical compositions from 5 populations of Chamaecyparis obtusa with several environmental factors were investigated through essential oil extracted distillation apparatus and metabolite profiling by GC-MS analysis. Among the populations, content of essential oil at Gokseong was significantly higher than other populations. To compare the several environmental factors affecting on chemical composition and essential oil yields from C. obtuse at Gokseong, the environmental factors (soil condition, temperature, humidity, and moisture content) were measured during 1 year. The essential oils at Goksung based on humidity on March, July, and November was significantly different from other months. The essential oils at Goksung based on temperature on July and August was significantly different from other months. The essential oils at Goksung based on the moisture content on September were significantly different from other months. The percentage of T-N, OM, and yield of oil at Gokseong were significantly different on from other populations. The main constituents of C. obtusa at all populations were ${\alpha}$-pinene, ${\beta}$-pinene, ${\alpha}$-terpinene, ${\gamma}$-terpinene, terpinene-4-ol, isobonyl acetate, terpinyl acetate, and cedar acetate. Specially, Essential oil compositions (%) of ${\alpha}$-terpinene and cedar acetate were higher at Gokseong than at other populations. The chemical compositions of essential oils were variable depend on populations and environmental conditions. Therefore, this study might be used as fundamental research on study for selection of high productive terpenoids and for understanding about biosynthesis of essential oils in C. obtusa.

• Journal of Ginseng Research
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• v.28 no.1
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• pp.60-66
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• 2004

“The Regional complex long-term program of restoration (reintroduction) of Primoryes ginseng population up to 2005” elaborated by Primorye governor administration, Regional Committee of Natural Resources and Russian Academy of Sciences operates in Russian Primorye. The Institute of Biology and Soil Science (IBSS) provides the scientific implementation of the program including the genetic analysis of extant ginseng populations, plant reproduction and off-spring identification. According to our investigations, the genetic resource of P. ginseng in Primorye is represented by three populations of wild-growing ginseng and a few pritate plantations. The results obtained by RAPD allowed concluding that the resource is dispersed among the wild and cultivated ginseng sub-populations in such a way that each of sub-populations studied has to be represented as a stock material to maintain species genetic variability. The allozyme analyses also showed that the small sub-populations of wild ginseng are characterized by unique genetic diversity and, therefore, they all need to be represented in reintroduction centers. Additionally the allozyme analysis discovered that the Blue Mountain and Khasan populations possess the most genetic diversity. So, at least one more reproductive ginseng unit has to be created besides two already existing reintroduction centers representing the Sikhote-Alin and the Blue Mountain populations.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.408-418
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• 1999

On the basin of RAPD analysis, genetic diversity and structure of the natural populations of Abies holophylla was estimated by AMOVA procedure. The average value of percent of polymorphic markers was 71.9%. Most variation existed among individuals within population(80.2%). Genetic differentiation among populations(${\Phi}_{ST}$) was 0.198. When the populations were grouped as two region(i.e., Taebaek and Sobaek Mountain Regions), 8.5% of the total genetic variation was explained as regional differences. The heterogeneity of molecular variance among populations was investigated with Bartlett's test, which revealed that populations of Mt. Taebaek and Mt. Gariwang were more heterogeneous. Generally, the populations of Taebaek Mountain Reion were more heterogeneous than those of Sobaek Mountain Reion. Finally, the applicability of AMOVA to the populations frenetic study was discussed in comparison with other measures of genetic differentiation which were widely used.

• Korean Journal of Plant Taxonomy
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• v.33 no.4
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• pp.359-371
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• 2003

Numerical analyses using 28 morphological characters from 14 populations of four Korean Orostachys species were conducted to investigate infra-specific variation and to test species relationships. The resulting phenogram recognized three distinct clusters, and the populations of O. malacophyllus, O. iwarenge and O. minutus were closely related each other. The populations of O. japonicus from Gaeksanri (I) and Gadeuk-do were isolated from the remaining populations of the species, and it suggests that the ranges of morphological variation within the species are significant, and related to the previous cytological variation. The Jungdongjin population of O. malacophyllus was not grouped together with the same species, but was clustered with the populations of the O. japonicus, and suggested that it seems to be an unrelated population in O. malacophyllus. The results of the PCA analysis recognized two distinct groups: the populations of O. japonicus and remaining species populations. The populations of O. malacophyllus, O. minutus and O. iwarenge placed within the closely related species.

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.400-410
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• 2015

Juniperus chinensis (Cupressaceae) is a valuable woody plant resource, but this rare plant is only distributed in restricted regions in Korea. In this study, we surveyed the geographic distribution regions, variation of sex ratio and the dynamics of natural populations of J. chinensis. in order to establish conservation strategies for the sustainable conservation of this important resource tree. The 17 natural populations of J. chinensis are restrictively distributed in the shore cliffs of (1) Ulleungdo island, (2) Gyeongju-si to Gangneung-si of the eastern coast, the riverside cliff along (3) Donggang-river of Jungsun-gun and Pyeongchang-gun and (4) branch of Nakdonggang-river in Uiseong-gun. The populations in Ulleungdo island showed continuous population distribution of over 200 individuals, but populations in other regions had discontinuous population distribution of under 200. The population of J. chinensis surveyed in Korea was estimated in ca. 3,200 individuals. The sex ratio (male/female) among populations of J. chinensis was diverse with variation from 0.46~1.67 range, but showed no significance. The sex ratio of the total individuals by species level was 0.74, and the percentage of female tree was significantly higher than the male. The results of dynamics analysis within population among regions showed that seedlings and saplings of J. chinensis in three regions surveyed were continuously regenerating. The distribution of DBH class showed a stable population structure of inverse J shape graph, but fragmentation and decrease in populations because of invading broad-leaved shrubs and trees from the surroundings were concerned. Further studies, and in situ and ex situ conservation strategies for the sustainable conservation on natural populations of this rare resources woody plant, J. chinensis in Korea are recommended.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.509-521
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• 2002

'The Regional complex long-term program of restoration (reintroduction) of Primoryes ginseng population up to 2005' elaborated by Primorye governor administration, Regional Committee of Natural Resources and Russian Academy of Sciences operates in Russian Primorye. The Institute of Biology and Soil Science (IBSS) provides the scientific implementation of this program including the genetic analysis of extant ginseng populations, plant reproduction and offspring identification. According to our investigations, the genetic resource of P. ginseng in Primorye is represented by three populations of wild-growing ginseng and a few private plantations. The results obtained by RAPD allowed concluding that this resource is dispersed among the wild and cultivated ginseng sub-populations in such a way that each of sub-populations studied has to be represented in living plant collection as a stock material to maintain species genetic variability. The allozyme analyses also showed that the small sub-populations of natural ginseng are characterized by unique genetic diversity and, therefore, they all need to be represented in reintroduction centers. Additionally the allozyme analysis discovered that the Blue Mountain and Khasan populations possess the most genetic diversity. So, at least one more reproductive ginseng unit has to be created besides two already existing reintroduction centers representing the Sikhote-Alin and the Blue Mountain populations.

• The Plant Pathology Journal
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• v.34 no.6
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• pp.544-554
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• 2018

Tomato (Solanum lycopersicum) production in Ghana is limited by the root-knot nematode (Meloidogyne incognita, and yield losses over 70% have been experienced in farmer fields. Major management strategies of the root-knot nematode (RKN), such as rotation and nematicide application, and crop rotation are either little efficient and harmful to environments, with high control cost, respectively. Therefore, this study aims to examine morphometric variations of RKN populations in Ghana, using principal component analysis (PCA), of which the information can be utilized for the development of tomato cultivars resistant to RKN. Ninety (90) second-stage juveniles (J2) and 16 adult males of M. incognita were morphometrically characterized. Six and five morphometric variables were measured for adult males and second-stage juveniles (J2) respectively. Morphological measurements showed differences among the adult males and second-stage juveniles (J2). A plot of PC1 and PC2 for M. incognita male populations showed clustering into three main groups. Populations from Asuosu and Afrancho (Group I) were more closely related compared to populations from Tuobodom and Vea (Group II). There was however a single nematode from Afrancho (AF4) that fell into Group III. Biplots for male populations indicate, body length, DEGO, greatest body width, and gubernaculum length serving as variables distinguishing Group 1 and Group 2 populations. These same groupings from the PCA were reflected in the dendogram generated using Agglomerative Hierarchical Clustering (AHC). This study provides the first report on morphometric characterisation of M. incognita male and juvenile populations in Ghana showing significant morphological variation.

• Journal of Ecology and Environment
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• v.43 no.3
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• pp.320-331
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• 2019

Background: Dioecious plant species having both male and female plants have been investigated regarding sex-related characteristics such as sex ratio, sex-differential resource requirements, and spatial segregation of the sexes. Habitat loss and fragmentation are major threats to the survival of plant populations, but dioecious species are particularly more prone to such habitat degradation than non-dioecious species because of their dimorphic sexual system. We examined the sex-related demographics of two Ilex cornuta populations being different regarding land use history. Methods: During 2016-2017, we examined I. cornuta trees with a basal diameter ${\geq}1.5cm$ in the Yongsu-ri population (YS population) and the Gotjawal Provincial Park population (GP population). Plant sex (male, female, or unsexed) was identified. The tree size (basal diameter and height of the main stem), clonal production (the ramet numbers per genet), and vitality for each clone were measured. The associations between population, sex, tree size, clonal production, and vitality were examined using ANOVAs and contingency table analyses. Finally, point pattern analyses using O-ring statistics were conducted to assess spatial patterns. Results: Upon excluding unsexed trees, the YS population with 74 trees was significantly male-biased (0.66), while the GP population with only 26 trees had a 1:1 sex ratio. In both populations, males and females did not differ in tree size. Although the mean number of ramets differed significantly between populations, females tended to produce more ramets than males. The proportion of weak trees was significantly higher in the YS than in the GP population. Neither population showed evidence of spatial segregation of the sexes. Conclusions: The two populations of dioecious I. cornuta are characterized by the small number of trees and relatively high frequencies of non-reproductive trees. Both indicate that these populations are quite susceptible to environmental and genetic stochasticity. On the other hand, the differences between populations in sex ratio, clonal production, and vitality suggest that conservation efforts for I. cornuta need to be population-specific. In order to help recover and enable this vulnerable species to persist, it is necessary to find ways to enhance their sexual reproduction and simultaneously reduce habitat disturbances due to anthropogenic activities.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.298-308
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• 2020

Genetic diversity among Thaumatococcus daniellii populations in the southwestern region of Nigeria were assessed using morphometric and molecular markers to determine the population structure and existing genetic relationship for its improvement, conservation and sustainable utilisation. Populations from five locations in each of the six states were used for the study. Morphometric data were collected on folia characters and analysed for variability. Genome DNA was isolated from the plant leaf and amplified by polymerase chain reaction with inter-simple sequence repeat markers (ISSR) to determine the allelic polymorphism, marker effectiveness and genetic relationship of the population. The results showed significant variations in petiole length and leaf dimensions of the populations within and across the states. These morphometric traits are the major parameters that delimit the populations and they correlated significantly at P≤0.05. Analysis of the electrophoregram showed that the ISSR markers are effective for the diversity study. A total of 136 loci were amplified with an average of 7.16 loci per marker, 63.2% of the loci were polymorphic. The Principal Coordinate Analysis revealed that seven factors accounted for 81.6% of the variation and the dendrogram separated the populations into two major groups at a genetic distance of 10 (about 90% similarity) with sub-groups and clusters. Most populations within the state had a high degree of similarity, nonetheless, strong genetic relationship exists among populations from different states. The close relationship between populations across the states suggests a common progenitor, which are likely separated by ecological or geographical isolation mechanisms.