• Korean Journal of Plant Resources
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• v.36 no.6
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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 Korean Journal of Ecology
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• v.25 no.2
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• pp.93-100
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• 2002

In order to analyze the life cycle of A. artemisiifolia var. elation dormancy and some environmental factors inducing germination of the seeds were examined. The results were as follows : Dormancy of fertile seeds was broken in part within a month after seed collection in case of adequate moisture and alternating temperature was also effective in breaking dormancy. The temperature range, which allow germination was 12℃ ∼ 32℃. Optimum temperature for germination was 24℃. The seed of A. artemisiifolia var. elatior was light-independent. The difference of storage period appeared to have no particular effect on the viability of seeds at any time during the 9-month storage period. In the increasing temperature(IT) regime, A artemisiifolia var. elatior seeds started to germinate at 16℃, showing the higher temperature the greater germination rate, the final germination percentage was 99.34%. On the other hand, in the decresing temperature(DT) regime, seeds began to germinate at 20℃ with the 1.34% germination. An induced dormancy occurred at 12℃ making the 5.34% fecal germination in the DT regime. Low temperature was more effective to break dormancy than higher temperature Seeds of A. artemisiifolia var. elatior seems to be germinated in mid to late autumn or germination delayed until following spring. The above results suggest these variation of germination response in diverse environmental factors seems to be a physiological strategy to maintain their existence and to reproduce in the extreme thermal variation.

• Korean Journal of Plant Resources
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• v.13 no.3
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• pp.219-226
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• 2000

The experiments were conducted to investigate the characteristics of the seed germination and the bulb dormancy in Korean-native Allium victorialis L. by the physicochemical treatments. The characteristics of two Allium victorialis seeds was similar in shape, color and threshing but different in other characters. Weight of 1,000 grains in Ullrung-native was 14.8g corresponding to 2.1 times as compared with Odae-native. Seeding immediatly after seed collection of Ullrung-native only germinated and chemicals didn't affect in germination improvement. The germination rate, average days to germination and coefficient of germination of Ullrung-native was 86%, 42 days and 2.05 at the dark condition of control, respectively. The germination rate, average days to germination and coefficient of germination of Odae-native was 70%, 47 days and 1.5 at the dark condition of control and 82%, 47 days, 1.75 at the light condition after 5$^{\circ}C$ prechilling for 30 days, respectively. The bedding days to reduce the physiological dormancy in the bulb of Odae-native assumed to be appropriate up to 45 days after the first prechilling.

• Journal of Ginseng Research
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• v.25 no.4
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• pp.167-170
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• 2001

Experiments were conducted to study the optimum chilling period for breaking physiological dormancy of dehisced ginseng(Panax ginseng C. A. Meyer) seed. Embryo of ginseng seed is too small to be noticed with naked eyed on harvesting time. Embryo grew to half size of endosperm after seeds were stratified for 3 months. It takes 6 months for this embryo to reach the size enough for germination. And it grew faster indoors than outdoors. Dehisced ginseng seed with full-size embryo did not germinate at room temperature and required chilling treatment for 75days in outdoors and 90 days in cold chamber. While seed receiving sufficient chilling treatment were left to be in room temperature, the chilling effect decreased remarkably.

• Journal of Ginseng Research
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• v.21 no.1
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• pp.39-42
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• 1997

Dynamic parameters of biochemistry including the contents of soluble carbohydrate (SC) , crude fat (CF) , fatty arid (FA) and soluble protein (SP) in American send (Panax qufnquelolium L.) seed are reported in the present paper. When embryo ratio (ER) increased from 7.31 to 20.48%, the SC content decreased from 4.08 to 1.16%. After that, SC content changed little. The CF content decreased successively from 34.50 to 14.40% from the beginning to the end during the embryo afterripening. The changes of FA content did not correlate with that of ER and the changing range of SP content was not large during the seed stratification. All of these may provide some information for understanding the dormancy mechanisms of American seng seed.

• Horticultural Science & Technology
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• v.33 no.3
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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.

• Korean Journal of Medicinal Crop Science
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• v.25 no.4
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• pp.209-216
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• 2017

Background: Dehisced ginseng seeds need to be stored at cold temperatures for around 3 months to break their physiological dormancy, and thus, to aid in gemination. In the presence of high moisture in such an environment, seed spoilage and pre-germination may lower seed quality and productivity. To improve seed quality during cold-stratification, the effects of seed dehydration and temperature were tested. Methods and Results: In early December, dehisced ginseng seeds were dehydrated at 4 different levels and stored at $2^{\circ}C$ $-2^{\circ}C$, and $-20^{\circ}C$ for 3 months. Germination was carried out on the filter papers moistened with distilled water; emergence of root, shoot, and seed spoilage were assessed. Seed viability was examined by the tetrazolium test. More than 90% of the seeds stored at $2^{\circ}C$ and $-2^{\circ}C$ without drying or endocarp dehydration germinated, but seeds that were dehydrated to have a moisture content (MC) below 31% showed poor germination and lost their viability. In addition, the seeds stored at $-20^{\circ}C$ failed to show effective germination. Conclusions: Seed storage after endocarp dehydration might help to improve seed quality and increase seedling's ability to stand during the spring-sowing of ginseng.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.372-377
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• 2017

This research was performed to develop mass propagation method of Alpine modest primrose (Primula modesta var. hannasanensis T.Yamaz.) for improving the conservation and utilization of the species. Seeds were collected on August 2011 in Jeju-city and well-selected seeds were dry-stored at $4{\pm}1.0^{\circ}C$. Seed size ranged $0.44{\pm}0.07{\times}0.61{\pm}0.04mm$, and weight of 1,000 seeds was $51.78{\pm}0.021mg$. Thus the seed was classified as 'dwarf seeds'. As the result of dormancy characteristics, moisture content of freshly matured seeds increased rapidly by water-soaking treatment and seeds did not germinate at $20^{\circ}C$ for 4 weeks under the light condition. Therefore, seeds were estimated to have physiological dormancy. Germination conditions of dry-stored seeds were found to be $20^{\circ}C$ and light condition, and seeds did not germinated under dark condition regardless of all temperature regimes. Therefore, Alpine modest primrose seed was considered as photoblastic type. Percent germination (PG) and germination energy (GE) were greatly improved by soaking the seeds in $GA_3$ and kinetin for 24 hours. Especially, 200~500 mg/L $GA_3$ treatment resulted in the highest PG (95.5%) and GE (98.3%). So, chemical treatment such as $GA_3$ was thought to be a useful method for raising seedling uniformly.

• Korean Journal of Environmental Agriculture
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• v.12 no.2
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• pp.193-207
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• 1993

The seed dormancy of weed species is the important mechanisms to unfavorable conditions but it brings about critical problems in weed control. The factors which induced dormancy were varied with species and their physiological conditions. More than 20 of 50 species of dominant weed species showed the seed dormancy. When several physical treatments were given to seeds to break the dormancy, each species showed the different responses. The germination percentage and germination velocity were increased with alternating temperature. The treatment of more than 4 weeks of stratification had strong effect on dormancy breaking. The ${\alpha}-amylase$ activities of germinating seeds were increased in proportional to the period of stratification treatment of dormant seeds. The contents of soluble protein and soluble sugar were changed slightly with stratification.

• Journal of Forest and Environmental Science
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• v.36 no.4
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• pp.267-273
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• 2020

Diospyros mespiliformis is a highly valued and threatened tree species within the Sahelo-Sudanian zone of Africa, but its seed germination requirements under cultivation are not well researched. In a first experiment which aimed at determining germination response of seeds to dehydration, fresh seeds were dried at room temperature for 26 days during which their moisture content, their germinability, and their viability were monitored at two-day intervals. In the second experiment, 14 pre-germination treatments were tested for their effect on the germination of dried seeds. Results showed that fresh seeds had 52.7% moisture and achieved 97.7% germination. As seeds were dried, percentage germination gradually decreased with decreasing moisture content and reached 0% when moisture content had dropped to 18%. Meanwhile, seed viability remained at 100% over drying duration. Seeds that were not germinated after air dry also recorded 100% viability. The most effective treatment for inducing germination of dried seeds was scarification using 98% sulfuric acid for 30 min which resulted in 96.6% germination. This study reports for the first time in D. mespiliformis seeds a desiccation-induced dormancy which can be efficiently alleviated by acid scarification. This study provides useful information that will contribute to efficient management of D. mespiliformis seed resources for propagation.