• Journal of Life Science
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• v.16 no.2 s.75
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• pp.213-218
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• 2006

The study of genetic diversity and population structure was carried out in the Codium fragile using allozyme analysis. Although this species has been regarded as a ecologically and economically important source, there is no report on population structure in Korea. Starch gel electrophoresis was used to investigate the allozyme variation and genetic structure of four Korean populations of this species. Of the 15 genetic loci surveyed, nine (60.0%) was polymorphic in at least one population. Genetic diversity was high at the species level ($H_{ES}$=0.144), and, that of the population level was relatively low ($H_{EP}$=0.128). Nearly 87% of the total genetic diversity in C. fragile was apportioned within populations. The predominant asexual reproduction, population fragmentation, low fecundity, geographic isolation and colonization process are proposed as possible factors contributing to low genetic diversity in this species. The indirect estimated of gene flow based on $G_{ST}$ was 1.69. The moderate level of gene flow in C. fragile populations is mainly caused by thallus developed from isolated utricles dispersal via sea current.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.246-254
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• 1991

Genetic structure of a Pinus densiflora population consisting of two subpopulations on the north-and south-facing slopes of a mountain was studied by allozyme analysis. Allozyme variants in aspartate aminotransferase(AAT), glutmate dehydrogenase(GDH) and leucine aminopeptidase(LAP) systems are encoded, at least, by eight loci ; five for AAT, one for GDH and two for LAP. Average number of alleles examined over six loci was 3.33. Average heterozygosity and genetic diversity computed over six loci were, respectively, 0.19 and 2.76 for parental population, 0.17 and 2.22 for progeny population. Differences in allelic frequencies between maternal sources at many of the investigated loci were found and between subpopulations on the north- and south-facing slopes. Allele frequencies of maternal origin at some of the loci were significantly different from each other between the two subpopulations. Thus it appears that the matings within and between subpopulations were not random and the mountain ridge that divides the north-and south-facing slopes isolate the two suhpopulations reproductively to a great extent. Some of the genotypes both in parental and progeny(embryo) groups deviate significantly from the Hardy-Weinberg equilibrium state. It appears from the result that the pine population is originated from a few limited ancestral trees and thus consanguineous matings are prevalent in this pine population.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.295-311
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• 2005

Starch gel electrophoretic studies using 24 populations of five Korean Orostachys species were conducted to investigate allozyme variation and to test hypotheses of systematic relationships among species. The resulting phenogram showed that the populations of five Korean Orostachys species were divided into two major groups. And they were concordant with molecular and morphological data in suggesting that Orostachys was divided into two groups corresponding to the subsect. Appendiculatae and subsect. Orostachys. The low genetic identities among Korean Orostachys species indicated that the species of Orostachys have diverged gradually through the model of geographical species. Comparing the previous genetic data from the species with similar life history and mode of reproduction, most of Korean Orostachys species revealed a significant low genetic variation, while the widespread O. japonicus showed a relatively high genetic variation among the Korean species. This kind of genetic variation pattern might be the results of the isolated habitats, limited numbers of individuals within the populations, destruction of habitats, inbreeding and asexual reproduction in Korean Orostachys populations. The Jungdongjin population (POP 21) of O. malocophyllus was genetically unrelated with remaining populations of the same species, and this interpretation was consistent to the results from the previous palynological and morphological studies. Our allozyme data supported the taxonomic treatment of recently proposed taxa, O. iwarenge (Makino) Hara for. magnus and O. margaritifolius.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.242-247
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• 1989

This study was conducted to estimate the inheritance of allozyme variants in IDH, ME and PGI, using megagametophyte tissue of seeds of Pinus densiflora and Pinus thunbergii in Kyungpook province. Two alleles at a single locus were detected for MH in Pinus densiflora, but Pinus thunbergii showed no varition, showing only one band. Four alleles at one locus were determined for ME in Pinus densiflora and Pinus thunbergii. Two loci were found for PGI and no variation seemed to occurred in A-locus as the presence of one single band. Five alleles were presented in B-locus in Pinus densiflora, but two alleles $B_1$ and $B_2$ in Pinus thunbergii. In PGI, an allozyme composed of multiple bands is observed from haploid megagamtophyte tissues. The isozyme variants of IDH, ME and PGI were appeared to segregate into 1 : 1 ratio for all zones.

• Korean Journal of Plant Taxonomy
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• v.49 no.2
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• pp.118-126
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• 2019

The taxonomic rank of the tiny-leaved terrestrial orchid Cephalanthera subaphylla Miyabe & $Kud{\hat{o}}$ has been somewhat controversial, as it has been treated as a species or as an infraspecific taxon, under C. erecta (Thunb.) Blume [C. erecta var. subaphylla (Miyabe & $Kud{\hat{o}}$) Ohwi and C. erecta f. subaphylla (Miyabe & $Kud{\hat{o}}$) M. Hiro]. Allozyme markers, traditionally employed for delimiting species boundaries, are used here to gain information for determining the taxonomic status of C. subaphylla. To do this, we sampled three populations of five taxa (a total of 15 populations) of Cephalanthera native to the Korean Peninsula [C. erecta, C. falcata (Thunb.) Blume, C. longibracteata Blume, C. longifolia (L.) Fritsch, and C. subaphylla]. Among 20 putative loci resolved, three were monomorphic (Dia-2, Pgi-1, and Tpi-1) across the five species. Apart from C. longibracteata, there was no allozyme variation within the remaining four species. Of the 51 alleles harbored by these 17 polymorphic loci, each of the 27 alleles at 14 loci was unique to a single species. Accordingly, we found low average values of Nei's genetic identities (I) between ten species pairs (from I = 0.250 for C. erecta versus C. longifolia to I = 0.603 for C. falcata vs. C. longibracteata), with C. subaphylla being genetically clearly differentiated from the other species (from I = 0.349 for C. subaphylla vs. C. longifolia to 0.400 for C. subaphylla vs. C. falcata). These results clearly indicate that C. subaphylla is not genetically related to any of the other taxa of Cephalanthera that are native to the Korean Peninsula, including C. erecta. In a principal coordinate analysis (PCoA), C. subaphylla was positioned distant not only from C. falcata, C. longibracteata, and C. longifolia, but also from C. erecta. Finally, K = 5 was the best clustering scheme using a Bayesian approach, with five clusters precisely corresponding to the five taxa. Thus, our allozyme results strongly suggest that C. subaphylla merits the rank of species.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2005.09a
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• pp.226-229
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• 2005

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.49.2-49
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• 1999

No Abstract, See Full Text

• Journal of Life Science
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• v.23 no.6
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• pp.728-735
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• 2013

Plantago asiatica (Plantaginaceae) is a wind-pollinated plant that grows mainly on fields in East Asia. Starch gel electrophoresis was used to investigate the allozyme diversity and population structure of 18 populations of this species. Although the plantain populations were isolated and patchily distributed, they maintained a high level of genetic diversity; the average percentage of polymorphic loci was 57.1%, the mean number of alleles per locus was 2.07, and the average heterozygosity for 18 populations was 0.201. The combination of a predominant wind-pollinated, mix-mating reproduction, large population sizes, high gene flow between subpopulations, and a propensity for high fecundity may explain the high level of genetic diversity within populations. A direct gradient in overall genetic diversity is associated with latitude. Genetic diversity of P. asiatica is markedly decreased from $35^{\circ}3^{\prime}$ to high latitude and decreased from $35^{\circ}3^{\prime}N$ to low latitude, whereas there does not show a longitudinal gradient in genetic diversity.

• Journal of Life Science
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• v.20 no.8
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• pp.1151-1158
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• 2010

The genetic diversity and population structures of fourteen Carex okamotoi (Cyperaceae) populations in Korea were determined using genetic variation at 25 allozyme loci. The Carex okamotoi species is native to Korea. It is endemic to three mountains (Mt. Taeback, Mt. Sobak, and Mt. Noreong) where it is found at 700~1,500 m above sea level. The percentage of polymorphic loci was 40.0%. Genetic diversity at the species level and at the population level was low ($H_{ES}$=0.106; $H_{EP}$=0.094), and the extent of the population divergence was relatively low ($G_{ST}$=0.082). Measurement of deviation from random mating ($F_{IS}$) within the 14 populations was 0.238. An indirect estimate of the number of migrants per generation was 2.78 (Nm=2.78). Analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and at some loci. Mean genetic identity between populations was 0.986.

• Animal Systematics, Evolution and Diversity
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• v.12 no.2
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• pp.121-136
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• 1996

In order to understand affinities and phylogeny of three families of the Superfamily Entomobryoidea allozyme analysis was performed with three species presumably representing each family, in addition to four species belonging to the neighboring Superfamily Poduroidea together. Electrophoresis for this purpose produced data for calculating allele frequency and enabled to obtain genetic distance and to depict dendrograms as well. The species of Isotomidae, Entomobryidae and Tomoceridae were clustered together whereas those of Hypogastruridae, Onychiuridae and Neanuridae were grouped as monophylies, respectively. Even though Tomoceridae and Entomobryidae were brought together they are considered complete families by showing high genetic distance value between them, thus supporting the hypothesis on their affinity among others. Gulgastrura reticulosa has been revealed to be separated from Hypogastruridae by being clustered rather with Onychiuridae. However, its high genetic distance value suggests the status as an independent family. The present result agreed with the phylogeny of Suborder Arthropleona divided into two Superfamilies mentioned above as in conventional systematics and also when compared with analysis of data of their morphological characters as well as 18S rDNA performed and published elsewhere by the present writers.