• Korean Journal of Plant Taxonomy
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• v.43 no.3
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• pp.181-187
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• 2013

Genetic variation in Asaum misandrum, a woodland herb in Korea, was investigated based on allozyme analysis with starch gel electrophoresis. All of previously reported populations in Korea were sampled and seven loci from six enzymes were analyzed. Overall genetic variation of A. misandrum population showed considerably high levels of genetic variation within the species (A = 2.05, P = 71.4, $H_E$ = 0.294). A positive $F_{IS}$ value of A. misandrum indicated overall deficiency of heterozygotes, and a low $F_{ST}$ value (0.112) meant very little differentiation among populations. Factors contributing to the high levels of genetic diversity found within populations of A. misandrum include population maintenance via wide distribution range from Korea to Japan and primarily outcrossing breeding system. Although it showed moderate genetic diversity level, most habitats of the species were scattered and discontinuous. Besides, low numbers of individuals were found in the most habitats and individuals are collected frequently from the wild due to the unique shape of the flowers as well as the rarity of the species. Thus, there is a need to set up a reasonable conservation strategies including the maintenance mechanism of genetic diversity of A. misandrum.

• Korean Journal of Plant Taxonomy
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• v.46 no.4
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• pp.371-377
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• 2016

The succulent herbaceous perennial Sedum sarmentosum commonly grows in the southern part of the Korean Peninsula. It is a species native to China, most likely introduced into Korea due to its edible and medicinal uses. If plants were introduced from a single source, we would expect no or low levels of genetic variation in Korean populations. Alternatively, if plants were introduced from multiple sources, we would expect, in contrast, high levels of genetic diversity. To test which is more likely, we surveyed the degree of allozyme variation in ten populations of this species from southern Korea. We found that S. sarmentosum was monomorphic at all fifteen allozyme loci. However, two congeners (S. polytrichoides and S. kamtschaticum) and two related species (Hylotelephium ussuriense and H. verticillatum) maintain moderate to high levels of genetic diversity ($H_e=0.144$, 0.203, 0.201, and 0.204, respectively). We suggest that southern Korean populations of S. sarmentosum likely descended from a single introduction of a few plants and then became naturalized exclusively via vegetative spreading (as plants in Korea, but also as occurs in other parts of its native and naturalized range, are sterile).

• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.267-274
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• 2012

To understand morphological and genetic differentiation between Euphorbia esula and E. maackii we examined 12 morphological characters and 11 isozyme loci from 14 populations of two species. Species of E. esula complex (A = 1.63, P = 44.83, $H_e$ = 0.198) in Korea maintain nearly as high as the genetic diversity reported in East Asian E. jolkinii and E. fauriei while lower than those of E. ebracteolata and E. pekinensis in Korea. Although the ranges of most morphological character variation of the two species overlap, E. esula and E. maackii were well recognized by the combination of the morphological traits, and the result of UPGMA phenogram supports the two distinct species inhibited in Korea. However, isozyme data do not support the recognition of E. esula and E. maackii. The discordance between morphological and allozyme data should be explained by the recent divergence or gene flow via introgressive hybridization between two species.

• Journal of Plant Biology
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• v.38 no.2
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• pp.173-180
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• 1995

We investigated levels and distribution of genetic variation in Korean populations of Calystegia soldanella and C. japonica, clonally reproducing herbaceous perennials. Calystegia soldanella is one ofecologically important beach plants growing only on sand and beach dunes in Europe, East Asia, the Pacific Islands, and the west coast of North America. In contrast, C. japonica usually grows on small mounds of paddy fields, roadsides, and waste places with patchy distribution. Starch gel electrophoresis was conducted on leaves collected from 13 populations of C. soldanella and eight populations of C. japonica. The levels of genetic variation of the two species are very comparable; means of expected heterozygosity (Hep) were 0.100 and 0.099 for C. soldanella and C. japonica, respectively. These values were also very similar to those for species with similar life-history and ecological traits. However, the proportion of total genetic diversity partitioned among populations (GST) of C. soldanella (0.146) was considerably lower than that of C. japonica (0.383). In addition, means of Nei's genetic identity (Ⅰ) for C. soldanella and C. japonica were 0.985 and 0.900, respectively, which supports a restricted gene flow resulting from obligate clonal reproduction of C. japonica. Significant differences in allele frequency were detected among populations at eight and nine of nine polymorphic loci for C. soldanella and C. japonica (P<0.01), respecitvely. Considering the ecological importance of C. soldanella, the isolated beach populations coupled with present destruction of natural habitats of the species may result in erosion of genetic diversity in the near future. In this respect, conservation efforts should be focused on those populations that currently maintain the most genetic diversity such as those populations in the eastern and southeastern Korean Peninsula and Hamduck Beach, Cheju Island.

• Journal of Korean Society of Forest Science
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• v.82 no.2
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• pp.166-175
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• 1993

The genetic variation patterns at 23 loci coding for 16 isozymes in eight natural populations of Pinus densiflora for. erects distributed in Kangwon-Kyungbuk region and 17 populations of Pinus densiflora and 13 populations of Pinus thunbergii were compared. The absence of marker alleles specific to P. thunbergii and almost the same allele-frequency distributions to those of P. densiflora did not support the hypothesis that P. densiflora for. erecta is a introgressive hybrid between P. densiflora and P. thunbergii. From the results of the hierarchial analysis of population differentiation using Wright's F statistics(1978), the frequency distributions of single-locus distance coefficients and other genetic analysis (genetic distance, cluster analysis, factor analysis, resin duct analysis), it was concluded that Pinus densiflora for. erecta cannot be treated genetically as a distinct group from other natural populations of P. densiflora.

• The Korean Journal of Zoology
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• v.32 no.2
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• pp.75-83
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• 1989

Surveys of electrophoretic variation in isozymes and general proteins encoded by 26 loci were conducted to assess species recognition and to estimate the degree of genic variation and species divergence for seven species of the genus Moroco inhabiting in Korea and Japan. Estimates of the average calculated heterozygosity per species of M semotilus, M sp., M percnurus, M lagowskii, M oxycephalus, M steindachneri and M jouyf are low: 0.021, 0.019, 0.051, 0.031, 0.023, 0.046, and 0.007, respectively, and observed heterozygosities are 0.038, 0.022, 0.060, 0.027, 0.025, 0.042, and 0.002, respectively. Allozyme analyses show these species to be distinct genetically with the lafter four species being more closely related one another than any one of them is to the rest of the species. However, these four species (M. lagowskii, M. oxycephalus, M. steindachneri and M jouyi), had unique genetic markers in each species to be recognized as valid species. These results contrast to the previous report of Chung et of. (1986) mainly due to their error in analyzing the isozyme pallems, particularly in MDH and PGI analyses. The genetic distances among M semotilus, M sp., and M percnurus are near the high end of the scale of such estimate for freshwater fish congeners. Based on estimated divergent time of these species of the genus Moroco (5 to 0.6 million years) it is assumed that they are speciated during late Pliocene to middle Pleistocene epoch prior to migration to Korean and Japanese waters through Paleo Amur River system.

• Journal of Korean Society of Forest Science
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• v.68 no.1
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• pp.32-36
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• 1985

Megagametophyte tissues of Pinus densiflora were subjected to study the inheritance of acid phosphatase (ACP), alcohol dehydrogenase (ADH) and catalase (CAT) isozymes by starch gel zone-electrophoresis. At least three or four zones were segregated for ACP isozyme. However, as one isozyme of ACP-A zone was separated clearly, only that isozyme was analysed. Five isozyme phenotypes (A1-A5), observed in ACP-A zone, were segregated to a simple Mendelian ratio, suggesting that these are controlled by five codominant alleles existed at ACP-A locus. Two zones of activity were segregated in the gels after staining for ADH, the more anodal zone (ADH-A) of the two was invariant in our materials. Three isozyme phenotypes (B1-B3) were observed in ADH-B zone and these variants showed a 1:1 segregation pattern, suggesting that each variant is controlled by three codominant alleles at ADH-B locus. A total of five isozyme phenotypes, composed of multiple bands, were observed in CAT isozyme. The segregation of these phenotypes in heterozygous trees did not show any significant deviation from a 1:1 segregation. Therefore, the genetic control of CAT isozyme in Pinus densiflora seeds seems to be based on a single locus (CAT-A) with Five codominant alleles ($A_1-A_5$).

• Korean Journal of Plant Taxonomy
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• v.46 no.4
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• pp.361-370
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• 2016

An area comprising Juwangsan National Park and its adjacent mountains (southeastern Korean Peninsula) is a good model system for testing the effects of physical barriers to gene flows in plant populations. We predicted that plant species consisting of isolated populations are genetically more differentiated than those that are rather continuously distributed. Most populations of Sedum polytrichoides occur in four isolated valleys, and we assessed the genetic variability and structures using twelve allozyme loci in ten populations. We also compared the present results to earlier findings pertaining to the two co-occurring herbs Hylotelephium ussuriense (${\equiv}$ Sedum ussuriense) (growing only in the four isolated valleys) and S. kamtschaticum (rather continuously distributed). We found moderate levels of within-population genetic variation in S. polytrichoides ($H_{e}=0.112$). Estimates of among-population divergence in S. polytrichoides were also moderate ($F_{ST}=0.250$) and, as expected, very similar to that of H. ussuriense (0.261) but considerably higher than the variation in S. kamtschaticum (0.165). An analysis of molecular variance (AMOVA) revealed that S. polytrichoides and H. ussuriense had higher percentages of among-valley variation (19% each) than S. kamtschaticum (4%). Most of this variation, as also indicated by the STRUCTURE program, was due to differences in genetic profiles between the two central valleys. We concluded that the genetic differences observed between species (S. kamtschaticum vs. S. polytrichoides and H. ussuriense) are mainly due to differences in their distribution within the study area.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.39-50
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• 1979

Twelve Pinus taeda were used as mother trees and one P. rigida plus tree was used as pollen tree for 12 cross combinations. Nine P. densiflora plus trees(4 mother and 7 pollen trees) were used as parents for 11 cross combinations. Those parents and 10 progenies were analyzed for LAP of ${\times}$P. taeda rigida hybrid and P. densiflora and for peroxidase of ${\times}$P. taeda rigida. The analysis, based on the banding patterns, indicate three alleles for LAP-A locus(A1, A2, A3) and two alleles for LAP-B locus (B1, B2) in ${\times}$P. taeda rigida hybrids. Chi-square test on the segregation for progenies did not show significant differences. The results indicated good agreement with monohybrid Mendelian inheritance. Independence test for occurrence frequency of 2 alleles(LAP-A3, LAP-B2) illustrated that there is neither linkage nor repulsion relationship between LAP-A3 and LAP-B2 alleles. Three band at LAP-A locus were always exhibited from all parents and their progenies of P. densiflora. However, the occurrence of two bands at LAP-B locus was variable, one bands assumed as homozygous alleles(B2/B2) and two bands as heterozygous alleles(B1/B2). The segregation ratio for progenies of P. densiflora suggested that LAP-B locus may be controlled by two alleles(B1 and B2). Three Peroxidase loci(Px-A, Px-B, Px-C) assumed to be controlled by allozyme in ${\times}$P. taeda rigida hybrid. The Px-B and Px-C loci could not find out the variations from banding patterns of parents and their progenies, while the Px-A locus showed the variations of occurrence frequency by two bands. The segregation ratio for A1/A2 at LAP-A locus suggest that the peroxidase allozymes of ${\times}$P. taeda rigida hybrid appeare to be monomeric products; that is, Px-A locus may be controlled by two alleles (A1 and A2).