• Journal of Ecology and Environment
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• 제43권3호
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• pp.320-331
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• 2019

Background: Dioecious plant species having both male and female plants have been investigated regarding sex-related characteristics such as sex ratio, sex-differential resource requirements, and spatial segregation of the sexes. Habitat loss and fragmentation are major threats to the survival of plant populations, but dioecious species are particularly more prone to such habitat degradation than non-dioecious species because of their dimorphic sexual system. We examined the sex-related demographics of two Ilex cornuta populations being different regarding land use history. Methods: During 2016-2017, we examined I. cornuta trees with a basal diameter ${\geq}1.5cm$ in the Yongsu-ri population (YS population) and the Gotjawal Provincial Park population (GP population). Plant sex (male, female, or unsexed) was identified. The tree size (basal diameter and height of the main stem), clonal production (the ramet numbers per genet), and vitality for each clone were measured. The associations between population, sex, tree size, clonal production, and vitality were examined using ANOVAs and contingency table analyses. Finally, point pattern analyses using O-ring statistics were conducted to assess spatial patterns. Results: Upon excluding unsexed trees, the YS population with 74 trees was significantly male-biased (0.66), while the GP population with only 26 trees had a 1:1 sex ratio. In both populations, males and females did not differ in tree size. Although the mean number of ramets differed significantly between populations, females tended to produce more ramets than males. The proportion of weak trees was significantly higher in the YS than in the GP population. Neither population showed evidence of spatial segregation of the sexes. Conclusions: The two populations of dioecious I. cornuta are characterized by the small number of trees and relatively high frequencies of non-reproductive trees. Both indicate that these populations are quite susceptible to environmental and genetic stochasticity. On the other hand, the differences between populations in sex ratio, clonal production, and vitality suggest that conservation efforts for I. cornuta need to be population-specific. In order to help recover and enable this vulnerable species to persist, it is necessary to find ways to enhance their sexual reproduction and simultaneously reduce habitat disturbances due to anthropogenic activities.

• 식물분류학회지
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• 제47권3호
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• pp.189-195
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• 2017

Aruncus L. is a small genus which is distributed in the circumpolar regions of the Northern Hemisphere, including Europe, Asia, and North America. In Korea, there are two taxa, A. dioicus var. kamtschaticus and A. aethusifolius. Aruncus aethusifolius is a species endemic to Korea, occurring only on Jeju Island. An important characteristic of Aruncus is dioecy. However, there is some controversy regarding the sexuality of this genus, and little is known about A. aethusifolius. To characterize the sexuality of A. aethusifolius and to provide insight into the evolution of its sexual system, we investigated natural populations and herbarium specimens of A. aethusifolius. The results indicate that the species has carpellate, staminate, and bisexual flowers. Carpellate flowers are always borne on separate individuals, and staminate flowers are borne either on separate individuals or mixed with bisexual flowers on the same individuals. The sexuality of A. aethusifolius is defined as polygamo-dioecious. The polygamo-dioecious type is also found in A. dioicus var. dioicus and A. dioicus var. kamtschaticus and thus may be a general condition in Aruncus.

• Plant Biotechnology Reports
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• 제2권4호
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• pp.239-243
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• 2008

Simmondsia chinensis (Link) Schneider, a multipurpose and monogeneric dioecious shrub from arid zones, has emerged as a cash crop all over the globe. Its seed propagation poses severe problems due to its male-biased population: the male:female ratio is 5:1. Investigations have been carried out to generate a sex-specific Inter-simple sequence repeat (ISSR) marker for the early detection of male and female plants. Of the 42 primers analysed with a bulk sample of pooled male DNA and a bulk sample of pooled female DNA, only one primer, UBC-807, produced a unique ~1,200 base-pair fragment in the male DNA. To validate this observation, this primer was re-tested with individual male and female samples from eight cultivars. A similar unique ~1,200 bp fragment was present in the male individuals of all eight cultivars and completely absent in the female individuals tested. This is the first report of the use of ISSR markers to ascertain sex in physiologically mature S. chinensis plants.

• 식물조직배양학회지
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• 제25권5호
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• pp.309-313
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• 1998

본 연구는 국내의 경우 제주도의 일부지역에서만 자생하는 흑오미자(Schisandra nigra)를 RAPD법을 이용하여 자웅동주 및 자웅이주 식물의 특이적 Marker를 탐색하고저 실시 하였다. 10-mer로 구성된 80종류의 random primer를 사용하여 흑오미자를 분석한 결과 기존의 재배되고 있는 오미자(Schisandra chinensis) 또는 남오미자(Kadsura japonica)와는 다른 band pattern을 보여 주었다. 흑오미자의 자웅동주. 암그루, 숫그루의 3품종을 상기와 동일하게 80개의 primer를 사용하여 RAPD를 분석한 결과, 5종류의 random primer(OPA-17, OPA-19, OPB-3, OPB-9, OPB-16)에 대해서는 각 품종에 대한 특이적인 band가 검출되었다. 숫그루, 암그루 식물과는 다르게 자웅동주 식물은 3개체(1호 2호, 3호)간에도 서로 다른 band pattern을 보이는 특징을 갖고있다. 숫그루 특이적인 band pattern은 OPB-3 primer을 이용할 경우 750bp에서 검출되었고, 암그루는 OPA-19 primer에서 950bp, 1690bp와 OPB-3 primer의 경우 700bp에서 자웅동주 및 숫그루에서 나타나지 않는 band가 검출되었다. 이러한 결과는 흑오미자의 숫그루 및 암그루에서 나타난 특이적인 band가 유묘시기에 암ㆍ수 개체를 조기에 구별하는 genetic marker로 사용할 수 있으리라 기대된다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1998년도 한국생물과학협회 학술발표대회
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• pp.334.2-334
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• 1998

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.272.2-272
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• 1999

No Abstract, See Full Text

• Journal of Plant Biotechnology
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• 제50권
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• pp.207-214
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• 2023

Lindera obtusiloba (Lauraceae) is a dioecious tree that is widely distributed in the low-altitude montane forests of East Asia, including Korea. Despite its various pharmacological properties and ornamental value, the genetic diversity and population structure of this species in Korea have not been explored. In this study, we selected 6 nuclear and 6 chloroplast microsatellite markers with polymorphism or clean cross-amplification and used these markers to perform genetic diversity and population structure analyses of L. obtusiloba samples collected from 20 geographical regions. Using these 12 markers, we identified a total of 44 alleles, ranging from 1 to 8 per locus, and the average observed and expected heterozygosity values were 0.11 and 0.44, respectively. The average polymorphism information content was 0.39. Genetic relationship and population structure analyses revealed that the natural L. obtusiloba population in Korea is composed of 2 clusters, possibly due to two different plastid genotypes. The same clustering patterns have also been observed in Lindera species in mainland China and Japan.

• 한국자원식물학회지
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• 제16권1호
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• pp.55-60
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• 2003

암$.$수 개체 사이에 상이한 성염색체 조성을 지니는 자웅 이주 식물인 수영 (Rumex acetsa L.)에서 120개 의 10-mer random primer를 이용하여 RAPD 분석을 수행하였다. 적용한 primer들 중 24개의 primer 에서 34개의 암$.$수 특이 밴드가 관찰되었다 암 개체 특이 밴드는 16개였으며, 수 개체 특이 밴드는 18개로 나타났다. 특히 OPC-10 primer로부터 얻은 1,440 bp인 DNA 단편은 수 개체 특이적으로 나타났다. 본 연구에서 얻어진 성 특이적인 RAPD 마커들은 식물에서 성 결정 메커니즘 구명의 기본 자료로 활용될 수 있을 것이다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.188.3-188
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• 2003

No Abstract, See Full Text

• 한국자원식물학회지
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• 제33권6호
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• pp.682-688
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• 2020

Hemp (Cannabis sativa L.) is a dioecious plant, although monoecious plants are bred in some cultivars for fiber or seed production. Recently, hemp has received attention for medicinal use with some cannabinoids, including cannabidiol. Self-fertilization for breeding inbred lines is difficult because of dioeciousness and anemophily in hemp. This experiment was conducted to develop a self-fertilization method by forming female flowers and seeds from male plants of dioecious hemp. To induce the formation of female flowers on male plants, 500 mg L^-1 of ethephon was sprayed on plants at soon, seven and fourteen days after primordia formation. The plant ratio of female flowers formation and the number of harvested seeds were increased by ethephon treatment. Female flowers of male plants have 5 stigmas in contrast to the dual stigma of female 1plants. Male plant seeds were lighter and smaller than those from female plants. Although the germination rate was lower than that of normal seeds from female plants, the seeds from male plants germinated to grow seedlings. Thus, we suggest that hemp plants should be treated with ethephon at soon after primordia formation to induce the formation of more female flowers on the male plants.