• 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.

• Journal of Ecology and Environment
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• 제42권2호
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• pp.50-59
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• 2018

Background: Duodichogamy is the rarest form of dichogamy in angiosperms, which is characterized by flowering in the sequence of male${\rightarrow}$female${\rightarrow}$male. Disentangling factors promoting duodichogamy require the discovery of more duodichogamous species in angiosperms. However, extremely limited information on duodichogamous species makes it difficult to make general conclusions. Given the inflorescence morphology and flowering characteristics, the Meliaceae family is highly likely to contain duodichogamous species. Methods: We selected 48 individuals from 20 populations in Korea and investigated their flower morphology, arrangement of flowers by sexual condition within inflorescences, and flowering phases and duration of male and female flowers of Toona sinensis (Meliaceae) for 5 years (2011-2015) to determine if the species shows duodichogamous flowering. Results: Toona sinensis belonging to Meliaceae possessed functionally unisexual flowers with rudimentary parts of the opposite sex. The floral organs in male were larger than those in female, except for ovary length and width. In dichasium, male flowers were observed on primary or lateral branches, whereas female flowers were borne only on lateral branches. Overall, individuals from six different populations flowered in the male${\rightarrow}$female${\rightarrow}$male sequence, thereby male is blooming far longer than female flowers at the level of individual trees (male vs. female = 17-20 days vs. 2-4 days). Conclusions: This is the first study to report a duodichogamously flowering species, T. sinensis, within Meliaceae. Several flowering characteristics observed from T. sinensis may be important clues used to discover additional duodichogamous Meliaceae species. Short flowering period and relatively small number of female flowers, which is analogous to reduced ovule numbers observed in other duodichogamous species, may intensify male-male competition in T. sinensis. This study contributed to narrowing down potential candidates of duodichogamy based on their geographic distributions and flowering time.

• Journal of Plant Biotechnology
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• 제44권3호
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• pp.229-234
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• 2017

Photoperiod is one of the factors affecting productivity of cucumber plant by inducing ethylene hormone production and so triggering flower sex differentiation into female flower. However, only few studies have been perfomed in order to reveal the effect of photoperiod in molecular level in relation to the flower differentiation. Therefore, in this study, Mercy cultivar of cucumber (andromonoecious) was treated with photoperiod of 8, 12, 16 hours of light, while control received no treatment of additional light. Photoperiod of 8 hours was achieved by blocking the sunlight with shade net and 16 hours by giving longer light exposure using white LEDs. Cucumber's flowers were quantified and the apical and lateral shoots were extracted to evaluate the gene profile related to the photoperiod, ethylene production, and female flower differentiation, which were CsACS2, CsETR1, CsCaN, and CsPIF4 using PCR method. Photoperiod of 8 hours affected the production of female flower with average number of 6.7 flowers in main stem and 8.0 flowers in lateral stem, compared to photoperiod of 12 and 16 hours which produced 3.7 and 2.0 flowers in main stem with 7.0 and 11.3 in lateral stem, respectively. In silico studies in this experiment resulted in proposed model of signal transduction that showed the connection between ethylene production and flower differentiation. PCR analysis confirmed the expression of CsACS2, CsETR1, and CsCaN, that was positively correlated with numbers of female flowers in cucumber, but the expression of CsPIF4 that represent photoperiod haven't been confirmed correlated with the ethylene production and flower differentiation.

• Journal of Forest and Environmental Science
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• 제38권4호
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• pp.275-283
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• 2022

A study was designed to investigate the pattern of sexual dimorphism in a plantation of Garcinia kola. Twenty trees were randomly selected for the study and have been observed to flower regularly. A total of 100 inflorescence were randomly collected from the crown of each tree and 500 flowers randomly assessed within the period of four (4) flowering seasons. Floral sex assessment was done visually and with a hand magnifying lens; floral morphometric measurements (i.e. pedicel and perianth length and breadth), inflorescence length, and breadth) was taken using a veneer caliper; number of flowers per inflorescence and inflorescence per twig was counted; while, data analysis was conducted on excel using analysis of variance and pairwise t-test comparison. Four floral sexes were identified in the G. kola plantation studied which were unisexual male flowers, unisexual female flowers, cosexual unisexual male flowers, and cosexual hermaphrodite flowers. Three tree sexes were identified viz: inconstant male, invariant female, and cosexual trees. The plantation was significantly sexually dimorphic in floral sex and phenotypic traits (i.e. pedicel and perianth size), and as well as sexually dimorphic in tree sex and reproductive phenotypic traits (i.e. inflorescence size, number of inflorescences per twig, and number of flower bud per inflorescence). The sexual system of the plantation was therefore trioecious with features suggestive of evolving dioecy through the gynodioecious pathway.

• Journal of Forest and Environmental Science
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• 제26권2호
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• pp.95-102
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• 2010

Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant. Plant flowering and breeding characteristics are important for us to understand the reproduction of plant populations. The present study describes the floral biology and flowering phenology of J. curcas which is a prerequisite for hybridization program for genetic improvement through conventional breeding. The plant produces flowers in dichasial inflorescences. Normally, the flowers are unisexual, and male and female flowers are produced in the same inflorescence. Only a few male flowers are produced in an inflorescence, and fruits are produced only through pollination between different flowers from the same or different plants. This study includes a description of the inflorescence, flower anatomy of both male and female flowers, female : male ratio, pollen : ovule ratio, flowering phenology, pollen viability, stigma receptivity, comparison of selfing methods and a comparison of geitonogamy and xenogamy. This information may be useful in J. curcas breeding programmes.

• 한국산림과학회지
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• 제103권1호
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• pp.43-50
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• 2014

본 연구는 밀원수종으로 관심의 대상이 되고 있는 쉬나무를 대상으로 수꽃과 암꽃의 화밀 분비량, 당 함량 및 아미노산을 분석하고 수확할 수 있는 꿀의 양을 추정하기 위하여 실시하였다. 경기도 화성시의 2012년 쉬나무 수꽃의 개화 최성기는 7월 24일부터 26일이었으며, 평균 화밀분비량은 $2.73{\pm}0.73{\mu}L$, 화밀 당도는 17.4%를 나타냈다. 2012년 암꽃의 개화 최성기는 8월 7일부터 9일이었으며 평균 화밀분비량은 $0.63{\pm}0.49{\mu}L$, 화밀 당도는 25.7%를 나타냈다. 기상인자와 상관분석 결과, 화밀 분비량과 화밀 당도는 온도와 습도의 영향을 많이 받는다는 것을 알 수 있었다. 반면, 꽃 한 개당 당 함량을 산출한 결과, 수꽃은 $48.0{\pm}5.2{\mu}g$, 암꽃은 $37.8{\pm}8.7{\mu}g$으로 분석되었으나, 유의적인 차이는 없었다(Mann-Whitney's U-test, p=0.400). 이러한 당 함량을 가지고 수꽃 1개 화서에서는 최소 67.8 g, 암꽃 1개 화서에서는 최소 53.3 g의 꿀을 수확할 수 있을 것으로 추정하였다. 또한 아미노산 분석 결과, Serine, Glycine 및 Alanine은 수꽃에서 더 많은 함량이 검출된 반면, Asparatate, Glutamate, Asparagine 및 Glutamine은 암꽃에서 더 많은 함량을 나타내어 수꽃과 암꽃에서 7개의 아미노산 함량이 유의적으로 차이가 있음을 알 수 있었다.

• 식물분류학회지
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• 제31권4호
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• pp.359-373
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• 2001

본 연구에서는 우리나라에 분포하는 애기부들(Typha Augustifolia L.)에 대한 외부형태학적 형질을 조사하여 정확한 실체를 파악하고, 명명상의 혼란을 해소하고자 하였다. 우리나라에 분포하는 애기부들에 대한 학명으로 분류학적 한계의 규명없이 T. angustifolia L. 와 T. angustata Bory et Chaubard가 사용되어 왔다. Typha angustifolia와 T. angustata는 자화의 길이와 소포엽의 길이 비, 소포엽의 길이와 털의 길이 비에 의해 구분되어 왔다. 그러나 이러한 형질은 한 개체에서도 여러 가지 형태적 변이를 나타내고 있으며, 단변량 분석결과 우리나라의 애기부들은 자화와 소포엽의 길이 비 ($1.15{\pm}0.18$)와 소포엽과 털의 길이 비 ($1.00{\pm}0.06$)에서 연속적인 변이 양상을 보이고 있다. 따라서 이러한 형질로는 Typha angustifolia와 T. angustata를 구분할 수 없다. 따라서 T. angustata를 T. angustifolia의 이명으로 처리하였다. 한편, 주성분 분석결과에서 우리나라의 애기부들과 일본, 러시아, 미국등에 분포하는 T. angustifolia와 동일그룹을 형성한다. 따라서 우리나라에 분포하는 애기부들에 대하여 적합한 학명으로는 T. angustifolia가 사용되어져야 할 것으로 보인다.

• Journal of Forest and Environmental Science
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• 제37권1호
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• pp.35-43
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• 2021

The interspecific hybrid of Salix caprea and Salix gracilistyla has never been identified or studied in Korea. Accordingly, this study investigated the flower morphological characteristics of the interspecific hybrid between S. caprea and S. gracilistyla and compared the interspecific hybrid with S. caprea and S. gracilistyla, respectively. The female flowers were investigated for 12 characteristics and the male flowers were investigated for nine. For the female flowers, those of the hybrids were larger than those of S. caprea and S. gracilistyla in terms of catkin length (CL), bract length (BL), and bract width (BW). The hybrids are intermediates between S. caprea and S. gracilistyla in terms of ovary length, width, and stipitate length as well as gland length (GL). For the male flowers, those of the hybrids were bigger than those of S. caprea and S. gracilistyla in terms of CL, BL, and BW. The hybrids are intermediates between S. caprea and S. gracilistyla in terms of catkin width and stamen length (SL). A principal component analysis (PCA) of the female data showed that the first principal component (PC) explained 57.5% of the total variation. The first PC highly correlated the ovary stipitate and pistil style lengths. The analysis was divided into three groups of S. caprea, S. gracilistyla, and the hybrid by the first PC. The results of a PCA of the male data showed that the first PC explained 35.7% of the total variation. The first PC highly correlated with the adelphous SL and was divided into three groups of S. caprea, S. gracilistyla, and the hybrid. The results of the discriminant analysis showed that S. caprea, S. gracilistyla, and the hybrid were distinguishable by flower morphological characteristics. Therefore, the hybrid was distinctly separated from S. caprea and S. gracilistyla by flower characteristics.

• 원예과학기술지
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• 제34권5호
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• pp.701-707
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• 2016

여주(Momordica charantia)의 과실 이외의 새로운 부위에 대한 이용 가능성을 구명하고자 과실 수확 종료기 무렵의 식물체부위별 charantin 함량을 분석하였다. 그 결과 두 품종 모두 잎의 charantin 함량이 $131.4-138.0mg{\cdot}g^{-1}D.W.$으로 가장 높았고 과실은 $14.7-16.0mg{\cdot}g^{-1}D.W.$으로 가장 낮아 수확기 무렵에는 charantin 함량이 과실보다 잎이 약 8배 이상 높은 것으로 나타났다. 또한 어린 암꽃, 수꽃과 줄기의 함량도 과실보다 많은 것으로 나타났다. 수확기 무렵의 식물체 부위별 charantin 함량의 비율은 과실이 5%로 매우 낮았으며 줄기 12-13%, 수꽃 14%, 암꽃 20-21%, 잎이 48% 정도로 가장 높았다. 착과 후 14일에 채취한 과실의 수확시기별 charantin 함량은 6월부터 7월 중순까지 수확한 과실의 charantin 함량이 $20.2-23.3mg{\cdot}g^{-1}D.W.$으로 높았고, 7월 하순부터 8월 하순까지 수확한 과실은 $13.3-19.4mg{\cdot}g^{-1}D.W.$으로 낮았다. 따라서 charantin 함량이 높은 과실을 수확하기 위해서는 온도가 높고 과실 비대속도가 빠른 7월 중순 이전이 좋을 것으로 사료되었고, 여주 과실 수확 종료기에는 과실 내 charantin 함량보다 여주의 잎, 암꽃, 수꽃 및 줄기의 charantin 함량이 높기 때문에 버리지 말고 새로운 가공품 개발에 이용하면 좋을 것으로 사료되었다.

• The Korean Journal of Ecology
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• 제14권4호
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• pp.415-433
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• 1991

Seasonal variation in size and number of floral structures was examined in two massachusetts populations of chelidonium major, a self-compatible herb. All floral charcters except for anther number per flower declind significantly during a 3 week period. However, temporal patterns were not identical among characters or between popolations. The result indicate that floral characters varied in conjunction with flower diameter,but that the pattern of changes in floral characters in response to environments may not be easy to predict. Principal components analysis was conducted to environments may not be easy to predict. principal compenents analysis was conducted tl identify the functional relationship among floral male function, and female function, respectively, perhaps reflecting the functional distinction of floral characters. Based on this pattern, the relative allocation to sexual structures within flowers was examined: male allocation was relatively greater than female allocation eary or in the middle of flowering season, depending upon populations. Temporalvariation in relative allocation within flowers was not independent of seed tield components:; different combinations of the size and number of floral characters were correlated with different seed yield components, for example, either seed size or number per fruit, during a season. in particular, allocations to attractive and male structures were highly correlated with mean seed weight only earlier in the season. These result provide some evidence that flowering phenolgy is an important comportant to be considered in the study of sexual allocation.