• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.20-20
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• 2020

Eranthis stellata Maxim. is a perennial plant that grows around the valley. E. stellata is concerned about the decline in natural habitats due to climate change in KOREA, continues to be observed and protected as an endangered species (Least Concrned, LC). Nevertheless, studies on the characteristics of the seeds of E. stellata are insufficient. So, this study analyzed the morphological characteristics and dormancy types of seeds. Seeds of E. stellata was collected in April at Gyeongsangbuk-do Arboretum and kept at 5 ℃ until using. To investigate the morphology of seeds, an optical microscope and a scanning electron microscope (SEM) were used. GA3 treated or untreated seeds (4 replicates of 25 seeds each) were observed germination and embryo growth for 1 month at 5 ℃ and 25/15 ℃ (12h day/12h night). The seed surface of E. stellata, light brown, was observed as a common characteristic of Eranthis genus, reticulate. The short axis of seeds was 1.11~1.77mm (average 1.44mm), and the long axis was 1.27~1.91mm (average 1.63mm), which was investigated in a slightly round shape (subglose). While no germination was observed at all conditions, Embryo growth was observed at 5 ℃ both in the control group and with GA3treated groups. Thus, seeds of E. stellata are classified as morphological physiological dormancy (MDP), which requires embryonic development and dormant break at the same time. These results can be useful information for determining morphological physiological seed dormancy and germination, and will be an important basic data for seed propagation of E. stellata as a resource.

• Journal of Plant Biotechnology
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• 제7권1호
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• pp.75-80
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• 2005

Eleutherococcus senticosus (also called Acanthopanax senticosus), belonging to Araliaceae family, has been used as an important medicinal woody plant. Mature seeds of Eleutherococcus senticosus have rudimentary (extremely immature) zygotic embryos and require a long-term stratification for about 18 months to induce germination. Here, through the methods of endosperm removal and other exogenous treatments, we investigated the factors for inducing rudimentary embryos by in vitro culture, Rudimentary zygotic embryos in seeds were at globular to heart-shaped stage at about $250{\mu}m$ in length just after harvest of fruits. When the seeds without testa were cultured on 1/2 MS (Murashige and Skoog 1962) medium, they did not germinate regardless of medium and sucrose concentrations but the removal of endosperm tissue markedly stimulated the growth of rudimentary zygotic embryos. The embryo reached ear-lier maturation, once when the endosperm surrounding the rudimentary embryos was removed. Rudimentary zygotic embryos developed cotyledons within 3 weeks of culture after endosperm emoval. However, post-mature zygotic embryos failed to germinate though they were morphologically normal, indicating another dormancy of embryos. $GA_3\;(2.0\;\cal{mg/L})$ and/or charcoal ($0.2\%$) treatment rapidly enhanced the germination of zygotic embryos. These results suggest that E. senticosus seeds have double dormancy; i. e. morphological rudimentary dormancy influenced by surrounding endosperm and physiological dormancy after post-maturation of zygotic embryos. Based on the above findings, we established the rapid germination of rudimentary zygotic embryos by in vitro culture of excised seeds with endosperm removal and $GA_3$ treatment.

• 원예과학기술지
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• 제33권3호
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• pp.331-339
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• 2015

This research was performed to determine the temperature requirements for embryo growth and radicle emergence of Hepatica asiatica Nakai, a perennial herb native to Korea. Seed viability, embryo growth, and radicle emergence were monitored in seeds exposed to various temperatures (10, 15, $20^{\circ}C$ and $30{\rightarrow}15^{\circ}C$). Laboratory experiments at various temperatures revealed that (1) embryo elongation occurred effectively between 10 and $15^{\circ}C$; (2) radicle emergence occurred only at $15^{\circ}C$; (3) a warm stratification (2-8 weeks at $30^{\circ}C$) was not required for embryo elongation and radicle emergence, and led to inhibition of radicle emergence; (4) application of gibberellic acid ($GA_3$) promoted embryo growth, but not radicle emergence. These results suggested that H. asiatica seeds have two separate mechanisms to overcome dormancy, either by $GA_3$ (morphological dormancy) or temperature (physiological dormancy), and warm stratification is not involved in breaking radicle dormancy. These findings indicate that H. asiatica seeds have morphophysiological dormancy.

• Journal of Ginseng Research
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• 제46권2호
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• pp.225-234
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• 2022

Background: Ginseng, officially known as Panax ginseng Meyer, has been traditionally used as a medicinal herb, particularly in Asia. Ginseng is propagated from seeds; however, seed germination is challenging, especially in its natural environment on farms. The seeds typically exhibit morphophysiological dormancy and require release from both morphological and physiological dormancy before germination. Although some studies have proposed methods for increasing seed germination rates, the underlying mechanisms of its dormancy release process remain unclear. Here, we investigated metabolic alterations during dehiscence in P. ginseng to determine their potential roles in dormancy release. Methods: We compared the ginseng seed metabolome before and after dehiscence and the ginsenoside and phytosterol compositions of the seeds in both periods in the presence of related enzymes. Results: After seed dehiscence, the sugar, amino acid, and squalene concentrations were significantly altered, phytosterols associated with the stigmasterol biosynthesis pathway were increased, while ginsenoside and brassinosteroid levels were not significantly altered. In addition, squalene epoxidase, cycloartenol synthase, 24-methylenesterol C-methyltransferase, and the stigmasterol biosynthesis pathway were activated. Conclusion: Overall, our findings suggest that morphological activities that facilitate ginseng seed growth are the primary phenomena occurring during the dehiscence process. This study improves the understanding of P. ginseng germination processes and promotes further research of its germination and cultivation.

• 한국자원식물학회지
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• 제36권6호
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• pp.580-587
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• 2023

Androsace septentrionalis is a grass species restricted to North Korea; however, it is at the brink of extinction due to habitat loss and environmental changes caused by natural disasters and anthropogenic activities. This study was conducted to characterize the dormancy conditions of A. septentrionalis in an effort to conserve this North Korean plant resource. For this purpose, the morphological characteristics and vigor of A. septentrionalis seeds were examined, and its germination characteristics under different temperature conditions (15/6℃ and 25/15℃ ), low-temperature stratification, and gibberellin (GA₃) treatment were determined. The results revealed that A. septentrionalis exhibits non-deep type morpho-physiological dormancy, and low-temperature stratification treatment was not effective in breaking the dormancy of A. septentrionalis seeds. Meanwhile, GA₃ treatment significantly increased the mean germination time, rate, and speed of the seeds. The optimal conditions for the germination of A. septentrionalis seeds were 25/15℃ fluctuating temperature and 500 mg·L¹ GA₃ treatment. The results of this study are useful for the mass propagation of A. septentrionalis.

• The Plant Pathology Journal
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• 제18권6호
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• pp.328-332
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• 2002

Wheat samples showing typical spot blotch symptoms on stems and sheaths were collected from the field after physiological maturity, and were sealed in paper bags and stored in the laboratory at room temperature to study the survival of Bipolaris sorokiniana conidia on wheat straw. The materials were observed at monthly intervals to assess the conidia viability during storage. After 4 months, the frequency of individual conidia already present on wheat straw at the time of sampling was reduced and appeared to be progressively replaced by the formation of round structures consist-ing of conidia aggregates. After 5 months, distinct, individual conidia were no longer detected, and only 'clumps of conidia' were observed. These dark black aggregates or 'clumps of conidia’measured 157-170$\mu\textrm{m}$ in diameter and were grouped into boat-shaped olivacious conidia showing thick wall and measuring 50-82$\times$20-30$\mu\textrm{m}$. The germination was unipolar and below 0.5%, suggesting the occurrence of dormancy, In contrast, individual conidium produced on wheat during the growing season were 96-130$\times$16-20$\mu\textrm{m}$, slightly curved, hyaline to light pale, and euseptate with a bipolar germination reaching 98-100%. Bipolaris sorokiniana conidia produced on PDA were 55-82$\times$20-27$\mu\textrm{m}$, tapered at both ends, dark brown to olivacious, distoseptate, showed up to 1% germination, and were predominantly unipolar. Results of the present study suggest that B. sorokiniana conidia belonged to two different physiological categories corresponding to the pathogen's infection phase and its survival, respectively. The infection phase is characterized by a high germination percentage as opposed to the survival phase harboring apparent dormancy.

• 한국자원식물학회지
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• 제37권1호
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• pp.79-86
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• 2024

본 연구는 북한 식물자원 큰금매화의 종자 번식을 위해 발아에 대한 기초자료를 제시하고자 수행되었다. 큰금매화 종자의 형태적 특성과 활력을 검정하였고, 변온 조건(15/6℃ & 25/15℃), 저온층적처리 및 GA₃ 처리에 따른 발아 특성을 조사하였다. 연구 결과, 저온층적처리는 큰금매화 종자의 휴면타파에 효과가 없었다. GA₃ 처리는 큰금매화 종자의 발아율을 현저히 증가시켰고, 평균발아일수와 발아세 또한 유의미하게 향상시켰다. 한편, 15/6℃ 조건에 비해 25/15℃ 조건에서는 큰금매화 종자에 대한 GA₃ 처리의 효과가 감소하였다. 큰금매화 종자는 Nondeep-type의 형태·생리적휴면(MPD)을 가지는 것으로 판단되었고, 본 연구에서 가장 효율적인 발아 조건은 15/6℃ 변온조건과 GA₃ 500 mg·L^-1 처리로 확인되었다. 이러한 본 연구의 결과는 고산성 북방계 식물인 큰금매화의 대량증식에 유용한 자료가 될 것이다.

• 한국자원식물학회지
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• 제31권4호
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• pp.363-371
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• 2018

헐떡이풀은 우리나라에서 울릉도에서만 분포하는 자생식물로 전통적으로 약용으로 쓰여왔으며, 관상식물로의 활용도 기대되는 자원식물이다. 본 연구는 헐떡이풀 종자의 휴면타파와 발아를 위한 조건을 확립하고 종자휴면 유형을 분류하고자 수행되었다. 실험은 헐떡이풀 종자에 저온층적처리($5^{\circ}C$에서 0, 12주)와 고온층적처리($23^{\circ}C$에서 0, 4, 8, 12주 처리 후에 $5^{\circ}C$에서 8주, 다시 $23^{\circ}C$에서 배양함), $GA_3$ (0, 10, 100, 1000 mg/L)처리를 수행하였다. 이렇게 처리한 종자는 무균배지에 소독하여 파종하고 온도 $23^{\circ}C$, 광도 $40{\mu}mo{\ell}{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD, 일장16시간 조건의 배양실에서 배양하였다. 헐떡이풀 종자는 자연상태에서 미숙배인 상태로 탈리되며, 종자 내부로의 수분흡수에 대한 물리적인 장벽은 없었다. 그러나 아무 처리 없이 파종하였을 때 30일이 지나도록 전혀 발아하지 않았다. 따라서 헐떡이풀 종자는 형태적 휴면(MD)과 생리적 휴면(PD)을 가지고 있는 것으로 판단하였다. 저온층적처리(0, 12주) 실험의 최종 발아율은 각각 66.7%, 45.6%로 나타났다. 저온처리는 오히려 발아를 약 3주 정도 지연시켰다. 고온층적처리(0, 4, 8, 12주) 실험에서는 최종 발아율이 각각 13.3%, 24.4%, 20.0%, 51.1%로 나타났다. 헐떡이풀 종자의 배는 상대적 고온에서 발달하였다. $GA_3$ 처리는 종자의 휴면을 극복하고 발아를 촉진하였다. $GA_3$ 처리에서의 최종 발아율은 0, 10, 100, 1000 mg/L 처리구에 대하여 각각 33.3%, 45.0%, 42.5%, 72.5%로 나타났다. 위의 결과를 종합하여 헐떡이풀 종자는 non-deep simple 형태생리적 휴면(MPD)을 가지고 있으며, $GA_3$ 처리를 통해 고온을 대체하고 종자의 휴면을 타파할 수 있었다. 이는 한국에 자생하는 헐떡이풀속의 종자휴면에 대해 처음으로 보고한 논문이다.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권4호
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• pp.229-234
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• 2021

Iris dichotoma Pall. found on Daechung Island in Korea has been designated as an endangered species. To aid in conservation efforts of this species, this study investigated its germination characteristics and seed dormancy type. Four sets of seeds were incubated at different temperatures (4/1℃, 15/6℃, 20/10℃, and 25/15℃). One set of seeds was cold stratified (4 weeks at 4/1℃). The final germination rate and mean germination time showed that the optimal germination temperature was 25/15℃. Final germination rates were ~70%, showing no significant difference among temperature treatments. However, mean germination time were significantly different among all temperature treatments except for 4/1℃. Mean germination time for seeds with temperature treatments of 15/6℃, 20/10℃, and 25/15℃ were 3.2, 2.1, and 1.5 weeks, respectively. At 25/15℃, the mean germination time was half of that at 15/6℃. Seeds of I. dichotoma had fully developed embryos at the time of dispersal. No additional growth of the embryo was observed. Cold stratification did not affect the final germination rate or the mean germination time. This study shows that seeds of I. dichotoma have no physiological or morphological dormancy, unlike other members of the Iris genus known to have seed dormancy that needs a relatively high incubation temperature (≥25/15℃) for mass propagation to occur. These results will be useful for understanding ecophysiological mechanisms related to the species' habitat. They are also useful for mass propagation of I. dichotoma for the purpose of conserving this endangered species.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.23-23
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• 2023

The Hairy labrador tea (Ledum palustre L. var. diversipilosum Nakai) is a evergreen small shrub, belonging to the Ericaceae and mainly distributed along the alpine areas of Hamgyeong-do in North Korea. Through seed physiological research on North Korean plants, we intend to obtain basic data for the development of mass propagation methods and use them for vegetation restoration. The internal and external morphological characters of the seed were observed using scanning electron microscopy or stereoscopy, and full seeds were selected through X-ray test. Seeds were cultured on a growth condition at 15/6℃ and 25/15℃ to examine the germination response according to temperature, and the number of germinated individuals was examined every 24 hours to calculate germination percentage and mean germination time. Low-temperature treatment (4℃) and hormone treatment (GA3) were performed to investigate the effect of dormancy breaking, and analysis of variance (ANOVA) was performed on the experimental results using SAS 9.4. The seeds of the Hairy labrador tea were elliptical-narrow in shape, and the epidermal cell wall pattern was reticulated. The final germination rate (FGP) was the highest at 58.9% under the condition of low temperature treatment at 25/15℃. The average number of days to germination (MGT) was the highest at 25.1 days without treatment at 15/6℃, and the average of the last germination days was confirmed to be about 13 days. As a result of low temperature treatment, it was confirmed that the final germination rate (FGP) increased by 43.3%. The significance of the final germination rate (FGP) was verified according to the pretreatment at 25/15℃.