Man-Kyu Huh

Molecular Authentication and Genetic Polymorphism of Korean Ginseng (Panax ginseng C. A. Meyer) by Inter-Simple Sequence Repeats (ISSRs) Markers

Molecular authentication and genetic polymorphism of Korean ginseng cultivars and accessions were investigated using ISSR (inter-simple sequence repeat amplification) markers. Five primers among 56 produced clear and reproducible DNA fragments among seven cultivars and accessions. A total of 43 bands ranging from 250 bp to 1,700 bp from five primers were scored. Average number of bands per primer was 8.6 and only nine bands were polymorphic across the six Panax ginseng from Korea. Especially Chunpoong cultivar exhibited the highest level of polymorphism, whereas other accessions did not showed almost any polymorphism. Consequently, these ISSR markers will be available to differentiate Chunpoong cultivar from other major Korean ginseng cultivars and accessions, such as Yunpoong, Hwangsukjong and Jakyungjong, at the DNA level.

Comparison of RAPD, AFLP, and EF-1α Sequences for the Phylogenetic Analysis of Fusarium oxysporum and Its formae speciales in Korea.

Although Fursarium oxysporum causes diseases in economically important plant hosts, identification of F. oxysporum formae speciales has been difficult due to confusing phenotypic classification systems. To resolve these complexity, we evaluated genetic relationship of nine formae speciales of oxysporum with random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), and translation elongation factor-1 alpha (EF-1α) gene. In addition, the correlation between myeotoxin content of fusaric acid and isolates based on molecular marker data was evaluated using the modified Mantel’s test. According to these result, these fusaric acid-producing strains could not identify clearly, and independent of geographic locations and host specificities. However, in the identification of F. oxysporum formae speciales, especially, AFLP analysis showed a higher discriminatory power than that of a the RAPD and EF-1α analyses, all three techniques were able to detect genetic variability among oxysporum formae speciales in this study.

A Taxonomic Study of the Genus Spiraea in Korea Using Sequences of ITS

Genus Spiraea is a long lived woody species that is primarily distributed throughout Asia and Europe. We evaluated a representative sample of the fourteen taxa in Korea with nuclear ribosomal DNA internal transcribed spacer sequences (ITS) to estimate genetic relationships within genus. The molecular data allowed us to resolve well-supported clades in taxa. Aligned nucleotide sequences of the length of ITS1 were nearly constant within genus Spiraea varying from 237 to 238. However, S. pubescens and S. salicifolia were showed 227 bp and 242 bp, respectively. Especially, the 5.8S subunit of all taxa of Spiraea was found to 157-165 bp nucleotides. However, aligned nucleotide sequences of the length of ITS2 vary from 263 to 271 bp. Total alignment length is 670 positions, of which 65 are parsimony-informative, 45 variable but parsimony-uninformative, and 410 constant characters. The phylogenic tree showed Korean taxa of genus Spiraea were well separated each other. S. prunifolia for. simpliciflora and S. blumei are conform one group and S. chartacea is the sister to them. S. fritschiana and S. S. miyabei are conform one group and S. japonica is the sister to them. S. pubescens was recognized as a distinct species.

Genetic Diversity and Population Structure of Comus controversa Hemsley Using RAPD

Cornus controversa is a long-lived woody species mostly distributed in East Asia. Random amplified polymorphic DNA (RAPD) markers were used to investigate the genetic diversity and population structure of Korean populations of this species. A high level of genetic variation was found in seven populations of C. controversa. The mean genetic diversity (H) was 0.222 across populations, varying from 0.200 to 0.238. Eighty of the 93 loci (86.0%) showed detectable polymorphism in at least one population. Total genetic diversity values () varied between 0.192 and 0.231, giving an average overall polymorphic loci of 0.212. The interlocus variation of genetic diversity within populations () was high (0.167). Mean of genetic diversity in C. controversa was higher than average values for species with similar life history traits. The sexual reproduction, perennial habitat, and longevity are proposed as possible factors contributing to high genetic diversity. On a per locus basis, the proportion of total genetic variation due to differences among populations () ranged from 0.169 to 0.278 with a mean of 0.216, indicating that about 21.6% of the total genetic variation was among populations. An indirect estimate of the number of migrants per generation (Nm

The Paradox of the Plankton

Hutchinson (1961) proposed that the large number of species in most plankton communities is remarkable in review of the competitive exclusion principle, which suggests that in homogeneous, well-mixed environments species that compete for the same resources cannot coexist. The principle of competitive exclusion would lead us to conclude that only a few species could coexist in such circumstances. Nevertheless, numerous competing species in most natural habitats are able to coexist, while generally only few resources (niches) limit these communities. It is coined “the paradox of plankton” by Hutchinson. We reviewed some literature of the proposed solutions and give a brief overview of the mechanisms proposed so far. The proposed mechanisms that we discuss mainly include spatial and temporal heterogeneity in physical and biological environment, externally imposed or self-generated spatial segregation, horizontal mesoscale turbulence of ocean characterized by coherent vortices, oscillation and chaos generated by several internal and external causes, stable coexistence and compensatory dynamic under fluctuating temperature in resource competition, and finally the role of toxin-producing phytoplankton in maintaining the coexistence and biodiversity of the overall plankton populations. Especially we sited Roy and Chattopadhyay ’s reviews and their toxin-producing hypothesis by phytoplankton. This review may be some information to study plankton communities and effect to put the solutions to the paradox that have been proposed over the years into perspective.

Genetic Diversity and Phenetic Relationship of Dill (Anethum graveolens L.) by rps16-trnK DNA Sequences

Dill (Anethum graveolens L.) is an annual herb with a long history and it is mainly used as a spice and as a medicine that is effective as a digestive aid, a sedative, and a narcotic, and that helps remove bad breath. Dill grows wild in the districts along the shores of the Mediterranean Sea, West Asia, China, and Korea. An estimate of the phylogenetic relationships within dill accessions in 20 countries was inferred using data from the rps16-trnK3-intergenic spacer. The aligned data sets for dill ranged from 747 to 779 nucleotides (bp) as a result of the differences in the insert/delete nucleotides. The sequence variation within the dill accessions was mostly due to nucleotide substitutions, although several small insertions and deletions can be found. Among 100 accessions from 20 countries, the Eastern Asia accessions were more closely related to the North American accessions than to the Central Asia and European accessions. Although some accessions were not congruent completely with geographical locations, the dill accessions with rps16-trnK analysis resulted in plants with better-resolved clades.

Estimation for River Naturality in the Hwang River

I investigated the river morphology and river naturality according to the environment of the Hwang River. The numbers of flexions at the upstream regions were more than those of downstream regions. The Hwang River showed very low overall diversity of the flow. Materials of river shore at low channel width were mainly boulders or gravel at the upstream regions, and the middle and downstream were silts and clay. Artificial masonry and natural materials were mixed from materials of river levees. The Hwang River was some of the natural herbaceous vegetation to riparian zones. Land utilities for floodplain were extremely overall farmland were predominant, and partly used by natural vegetation in the forest, a soccer field, some park facilities, residential, and commercial facilities. The water was width sleep / rivers beam ratio of 10 to 20%. Currently estimation for river naturality widely used in rivers were consisted of a narrow wide a variety of items and did not reflect the actual.

Reproduction Strategies of Clonal Plants of Potentilla conferta in Uzbekistan and Mongol

Clonal plants combine sexual and clonal reproduction, which contribute differently to plant fitness. Reproductive analyses have highlighted the importance of clonal growth in shaping the spatial genetic structure in Potentilla conferta Bunge, a herbaceous rhizomatic clonal distributed in hot sand dunes. We investigated the reproduction system of P. conferta at two populations in Mongol and three natural populations in Uzbekistan. The measurements of 19 quantitative or qualitative morphological characters were taken on each of total individuals directly from their natural habitats. Some morphological characteristics between Mongolia and Uzbekistan populations showed a slight heterogeneity of variance. Especially, the length of internodes (LFI and LSI) and characteristics of root (LLR and NOR) were shown a significant difference between two countries (P

Application of Model of Plant Population Structure and Phenotypic Divergence

In application and discussion of population structure and phenotypic divergence in plant community, the classic Lotka-Volterra models of competition and spatial model are conceived as a mechanism that is composed by multiple interacting processes. Both the Lotka-Volterra and spatial simulation formulae predict that species diversity increases with genotypic richness (GR). The two formulae are also in agreement that species diversity generally decreases within increasing niche breadth (NB) and increases with increasing potential genotypic range (PGR). Across the entire parameter space in the Lotka-Volterra model and most of the parameter space in the spatial simulations, variance in community composition decreased with increasing genotypic richness. This was, in large part, a consequence of selecting genotypes randomly from a set pool.

ISSR을 이용한 고추나물 집단의 유전적 다양성과 계통학적 연구

Inter simple sequence repeat (ISSR) markers were performed in order to analyse the phylogenetic relationships of eight Hypericum electum populations in Korea. The six primers were produced 37 reproducible ISSR bands. Analysis of ISSR from individual plants of Korean H. erectum resulted in 22 polymorphic bands with 59.5%. Across populations, the mean number of alleles per locus was 1.348 and Shannon`s information index was 0.203.Population Mt. Gyeryong had the highest expected genetic diversity (0.175) among all populations. When species were grouped by eight populations, within group diversity was 0.140 (Hs), while among group diversity was 0.472 (G) on a per locus basis. The estimated gene flow (Nm) for H. erectum was very low (0.561). It is suggested that reproductive isolation by the isolation of geographical distance among H. electum populations and genetic drift may have played roles in shaping the population structure of this species. In phonetic tree, all populations were well separated from each other. Thus, ISSR markers are very effective in classifying natural population levels of genus Hypericum in Korea.