Notes on genetic variation in Sedum sarmentosum (Crassulaceae): Implications for the origin of southern Korean populations

정미윤,Jordi López-Pujol,정명기 한국식물분류학회 2016 식물 분류학회지 Vol.46 No.4

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 (He = 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).

Lack of allozyme variation in the two carnivorous, terrestrial herbs Utricularia bifida and Utricularia caerulea (Lentibulariaceae) co-occurring on wetlands in South Korea: Inference of population history

정미윤,Jordi López-Pujol,정명기 한국식물분류학회 2017 식물 분류학회지 Vol.47 No.4

In central and southern Korea, the two small insectivorous, terrestrial herbs, Utricularia bifida and U. caerulea, often co-occur at wet locations (or in wetlands). The Korean Peninsula (with central China and northern Japan) constitutes the northern edge of their distribution, as their main range is subtropical and tropical Asia. The Korean populations of both species are very likely of post-glacial origin, given that warm-temperate vegetation was absent from the Korean Peninsula during the Last Glacial Maximum. Two hypotheses of the post-glacial colonization of the peninsula can be formulated; first, if current populations were founded by propagules coming from a single ancestral population (i.e., a single refugium), we would expect low levels of genetic diversity. Alternatively, if contemporary Korean populations originated from multiple sources (multiple refugia), we would expect high levels of genetic variation. To test which is more likely, we surveyed the degree of allozyme variation at 20 loci in ten populations for each of the two species from southern Korea. We found no allozyme variation within each species. However, their aquatic congener U. australis exhibited allozyme polymorphism across Japan (four polymorphic loci at three enzyme systems). We suggest that southern Korean populations of Utricularia bifida and U. caerulea were established by a single introduction event from a genetically depauperate ancestral population.

Notes on fine-scale spatial distribution of three Cephalanthera species (Orchidaceae) that grow in sympatry in Korea: Implications for maintenance of species boundaries

정미윤,Jordi López-Pujol,정명기 한국식물분류학회 2017 식물 분류학회지 Vol.47 No.4

The three self-compatible, terrestrial orchids Cephalanthera erecta, C. falcata, and C. longibracteata flower synchronously in sympatric populations. Cephalanthera erecta and C. longibracteata, which have white flowers that do not fully open, are predominantly autogamous, whereas the food-deceptive C. falcata, whose bright yellow flowers open completely, is predominantly outcrossing. The formation of hybrids rarely occurs between species owing to strong prepollination barriers (floral isolation). If these three species have evolved toward the prevention of interspecific hybridization, we can expect that the spatial distribution patterns of the three species would be characterized as spatial segregation (i.e., ‘'spatial repulsion’') from each other. To test this prediction, we studied the three Cephalanthera species in sympatric populations showing coincident flowering within Yeonwhasan Provincial Park (YPP, Gyeongsangnam Province, South Korea). We found strong spatial aggregation in each population and spatial independence in the interspecific spatial distribution, differing from previous studies. We further hypothesize that Cephalanthera species in sympatry within YPP are distributed somewhat randomly in space, perhaps due to the sharing of similar mycorrhizal fungi.

Population genetic structure of Sedum polytrichoides (Crassulaceae): Insights into barriers to gene flow

정미윤,Jordi López-Pujol,정명기 한국식물분류학회 2016 식물 분류학회지 Vol.46 No.4

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 (≡ 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 (He = 0.112). Estimates of among-population divergence in S. polytrichoides were also moderate (FST = 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.

Is the Baekdudaegan “"the Southern Appalachians of the East”"? A comparison between these mountain systems, focusing on their role as glacial refugia

정미윤,Jordi López-Pujol,정명기 한국식물분류학회 2016 식물 분류학회지 Vol.46 No.4

Based on genetic studies and palaeoecological surveys, the main Korean mountain range, the socalled "Baekdudaegan" (BDDG), has been recently suggested to be a major glacial refugium at the Last Glacial Maximum (LGM) for the boreal and temperate flora of northeastern Asia. On the basis of its shared role as a glacial refugium, and on a series of striking similarities in floristic richness and orographic features, the BDDG would constitute a sort of “"eastern counterpart”" of the Southern Appalachians. Given its floristic, biogeographic, and cultural value, the BDDG merits high priority for conservation.

The genetically healthy terrestrial orchid Liparis krameri on southern Korean Peninsula

정미윤,정재민,손성원,Kangshan Mao,Jordi LÓPEZ-PUJOL,정명기 한국식물분류학회 2019 식물 분류학회지 Vol.49 No.4

Neutral genetic diversity found in plant species usually leaves an indelible footprint of historical events. Korea’s main mountain range (referred to as the Baekdudaegan [BDDG]), is known to have served as a glacial refugium primarily for the boreal and temperate flora of northeastern Asia. In addition, life-history traits (life forms, geographic range, and breeding systems) influence the within- and among-population genetic diversity of seed plant species. For example, selfing species harbor significantly less within-population genetic variation compared to predominantly outcrossers. A previous study of two Liparis species (L. makinoana and L. kumokiri) emphasizes the role of the abovementioned factors shaping the levels of genetic diversity. Liparis makinoana, mainly occurring on the BDDG and self-incompatible, harbors high levels of within-population genetic diversity (expected heterozygosity, HeP = 0.319), whereas there is no allozyme variation (HeP = 0.000) in L. kumokiri, which is self-compatible and mainly occurs in lowland hilly areas. To determine if this trend is also found in other congeners, we sampled five populations of L. krameri from the southern part of the Korean Peninsula and investigated the allozyme-based genetic diversity at 15 putative loci. The somewhat intermediate levels of within-population genetic variation (HeP = 0.145) found in L. krameri are most likely due to its occurrence in mountainous areas that, despite being outside of the main BDDG, still served as refugia, and a self-incompatible breeding system. Management strategies are suggested for L. krameri and L. makinoana based on the levels and distribution of genetic diversity and inbreeding.

Spatial and temporal variation on fruit set in Epipactis thunbergii (Orchidaceae) from southern Korea

정미윤,정명기 한국식물분류학회 2015 식물 분류학회지 Vol.45 No.4

Spatio-temporal variation in fruit set in orchids would affect long-term population viability and will influence genetic diversity over many generations. The aim of this study was to examine the breeding system of the nectariferous terrestrial orchid Epipactis thunbergii, to specifically determine levels of fruit set in terms of time and space under natural conditions. We examined pollination under natural conditions and conducted hand pollination experiments during a 2-year survey in four populations located along 1.5 km of coastal line in Jingui- ri (rual village) [Jeollanam-do (province), southern Korea]. We found that, over a 2-year period, levels of per- centage of fruit set were similar within patches of the four populations. By contrast, we detected significant dif- ferences in the percentage of fruit set among patches. We also found that plants with larger inflorescence size produced significantly more fruits than plants with fewer flowers. Over a 2-year period, the percentage of fruit set for E. thunbergii was similar but low (14.1%) compared to that averaged for eighty-four rewarding species (37.1%). However, an increase in fruit set was achieved by hand-pollinations: artificial self-pollination (90.5− 95.2%), artificial geitonogamy (94.7−95.0%), and cross-pollination (artificial xenogamy, 91.3−91.4%). No emasculated flowers produced fruits and no automatic pollination was found in E. thunbergii. Our findings sug- gest that E. thunbergii is a self-compatible terrestrial orchid that depends on pollinators (insects) to achieve fruit set in natural habitats, and that local environmental conditions were similar over a period of 2 years in the study area. Our results also highlight the cryptic variation of fruit production in time, but more pronounced variability in space.

Seed collection strategies for plant restoration with the aid from neutral genetic diversity

정미윤,손성원,Kangshan Mao,Jordi LÓPEZ-PUJOL,정명기 한국식물분류학회 2019 식물 분류학회지 Vol.49 No.4

One key step in the plant restoration process is the collection of seeds from the field. For the selection of source populations of target plant species for translocation purposes (reintroduction or reinforcements), several approaches are possible. A practical method involves the use of data from reciprocal transplant studies. If no direct data are available, knowledge of population genetics and the phylogeography of the target species can serve as an alternative. In this short review, we briefly propose guidelines for those collecting seeds for plant species restoration based on population genetics theory, focusing on two main questions: Where does the plant material come from and how are sources designated, and how are seeds efficiently collected from local populations? While genetic data on a larger scale (phylogeography and population genetics) are needed to form a reply to the first question, similar data on a smaller scale (fine-scale genetic structures within populations) are necessary to shed light on the second issue.

양자계의 시간의존 섭동에 대한 모의실험과 이의 시각화

정기수,정미윤 한국물리학회 2013 새물리 Vol.63 No.12

When a quantum system is perturbed a little, the original normal states are changed to other states. The representative method for interpreting such changes is the time-dependent perturbation theory. In this study, one-dimensional box was adopted as a quantum system, and different perturbations were numerically analyzed with Schr¨odinger’s equation; the results were compared with these calculated using perturbation theory. In the program that was developed, the type of perturbation and the initial conditions could be changed easily, which made possible the observation of the quantum state at any time by visualizing the variety of results. The program could be operated with the internet by loading it into a web document that included a theoretical description. At the same time, about 4 8 hours of virtual experimentation could be performed through the specific procedure, the method of simulation, and the data analysis method in the web document. 양자역학의 섭동이론은 계에 약간의 교란이 주어질 때 정상상태가 다른 상태들로 전이하는 확률을 계산하는 근사 이론이다. 본 연구에서는 양자계로서 1차원 상자를 택하고, 이에 여러 형태의 교란이 주어질 때에 대해 슈뢰딩거 방정식에서 직접 수치해석하고, 아울러 이를 섭동이론으로 계산한 결과와 비교하였다. 프로그램은 섭동의 형태, 초기상태 등을 그래픽 환경으로 쉽게 조작할 수 있도록 하였고, 그 결과를 다양하게 시각화시켜서 시시각각의 양자상태를 관찰할 수 있도록 하였다. 이들 수치해석 결과의 세부적인 데이터는 클립보드로 복사하여 스프레드시트 등 다른 프로그램으로 보다 정교하게 분석할 수 있게 하였다. 또한 이렇게 작성한 프로그램은 이론적인 설명과 더불어 웹문서에 탑재하여 인터넷으로 운용할 수 있다. 웹문서에는 실험절차와 실험방법, 데이터 분석방법 등을 구체적으로 제시하고 있고, 이를 통해서 약 4 ~ 8시간의 모의실험을 수행할 수 있다.

가교된 고분자 합성 및 2차 비선형 광학 특성

김홍근,진정일,정미윤 한국고분자학회 1998 한국고분자학회 학술대회 연구논문 초록집 Vol.1998 No.4