• 제목/요약/키워드: Cleistogamy

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한국산 제비꽃속의 종분화론적 연구 - 태백제비꽃군의 비교형태학적 연구 - (Biosystematic Study on the Genus Viola in Korea - Comparative Morphology of the Viola albida Complex -)

  • 김경식
    • Journal of Plant Biology
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    • 제34권3호
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    • pp.229-238
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    • 1991
  • The main objective of this study was to clarify the taxonomic status and the speciation mechanism of Viola albida complex in Korea. The complex includes three very closely related taxa, taxonomic ranks of which are much in dispute. These taxa in the complex are sympatric in distribution, and they are very similar in most morphological characteristics. Comparative morphological analyses revealed that they can be distinguished on the basis of leaf shape, although they show complicated patterns of variation in leaf shape. The variation of leaf shape in each taxon appeared to be maintained through developmental process, and extensive cleistogamy and vegetative reproduction in these taxa are suggested as the mechanisms maintaining the variation. Genetic variation in this complex was monomorphic in all 14 loci examined. Palynological study also showed that these taxa have the same pollen morphology. These results strongly suggested that they should be recognized as varieties of V. albida; var, albida, var. chaerophylloides, and var. takahashii. The results also suggested that some individuals that can be assigned to var. takahashii might be hybrids between var. albida and var. chaerophylloides.

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The optimal balance between sexual and asexual reproduction in variable environments: a systematic review

  • Yang, Yun Young;Kim, Jae Geun
    • Journal of Ecology and Environment
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    • 제40권2호
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    • pp.89-106
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    • 2016
  • Many plant species have two modes of reproduction: sexual and asexual. Both modes of reproduction have often been viewed as adaptations to temporally or spatially variable environments. The plant should adjust partitioning to match changes in the estimated success of the two reproductive modes. Perennial plants showed that favorable habitats in soil nutrients or water content tend to promote clonal growth over sexual reproduction. In contrast, under high light-quantity conditions, clonal plants tend to allocate more biomass to sexual reproduction and less to clonal propagation. On the other hand, plants with chasmogamous and cleistogamous flowers provides with a greater tendency of the opportunity to ensure some seed set in any stressful environmental conditions such as low light, low soil nutrients, or low soil moisture. It is considered that vegetative reproduction has high competitive ability and is the major means to expand established population of perennial plants, whereas cleistogamous reproduction is insurance to persist in stressful sites due to being strong. Chasmogamous reproduction mainly enhances established and new population. Therefore, the functions of sexual and asexual propagules of perennial or annual plants differ from each other. These traits of propagule thus determine its success at a particular region of any environmental gradients. Eventually, if environmental resources or stress levels change in either space or time, species composition will probably also change. The reason based on which the plants differ with respect to favored reproduction modes in each environmental condition, may be involved in their specific realized niche.

울릉도 희귀.특산 식물 섬현호색의 유전적 다양성과 구조 (Genetic Diversity and Structure of a Rare and Endemic, Spring Ephemeral Plant Corydalis filistipes Nakai of Ullung Island in Korea)

  • 김진석;양병훈;정재민;이병천;이재천
    • Journal of Ecology and Environment
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    • 제29권3호
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    • pp.247-252
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    • 2006
  • 울릉도의 특산 식물종으로서 희귀식물종이며, 춘계 단명성 식물로서 개미에 의해 종자 산포가 이루어지는 섬현호색(Corydalis filistipes Nakai) 4개의 아집단에 대하여 합리적인 보전 및 관리 대책 수립을 위하여 9 개의 동위효소 marker를 이용하여 유전적 다양성과 구조를 분석하였다. 그 결과 평균 대립 유전자의 수(A)는 1.73개, 95% 수준에서 다형적 유전자좌의 비율은(P)은 61.2%, 이형접합체의 평균 관측치(Ho)는 0.201, 기대치(He)는 0.167로서 분포역이 넓은 특산 식물 종들에 비해서는 낮은 수준이지만, 섬에 고립된 유사한 생활사를 갖는 특산식물 종들에 비해서는 높은 유전적 다양도를 유지하고 있는데, 그 이유는 소집단이기는 하나 적정수준의 개체수가 유지되고 있고, 타가수정을 주로 하며 개미에 의해 종자 산포가 이루어져 적응력이 높고, 또한 폐쇄화에 의한 유 무성 번식 체계를 겸하기 때문인 것으로 판단된다. 그리고 유전적 구조분석 결과 아집단내($F_{IS}$)와 전체 아집단($F_{IT}$)의 근친교 배계수가 각각 -0.1889 와 -0.1226로서 H-W의 평형구조에 비해 이형접합자의 빈도가 높았으며, 아집단간 유전적 분화도는 매우 낮은($F_{ST}=0.0557$)결과를 보였다. 그리고 우리나라 희귀 및 특산 식물종인 섬현호색의 유전적 변이의 유지 기작과 합리적인 보전과 관리 대책을 논의하였다.