• Journal of agriculture & life science
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• v.51 no.6
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• pp.15-22
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• 2017

The microstructure observation of seed surface structure is needed for protocols of breaking dormancy of seeds with physical dormancy. The seeds of Rubus species are surrounded by a thick, hard endocarp; together, the seed and endocarp make up the stone. We evaluate stone characteristics of 18 species of Rubus through optical microscopic observation, and correlate different stone characteristics with endocarp thickness. As a result of stone size comparison, Rubus species were classified as big stones group including R. parvifolius and R. idaeus, small stones group including R. longisepalus var. longisepalus, R. corchorifolius and R. hirsutus, and middle stones group including rest of the species. The result of this study revealed that stone size and the endocarp thickness in Rubus species was various characteristics in each species. Furthermore stone size and stone weight were also well correlated endocarp thickness and result indicated that heavy stones had harder endocarp than lighter one. Thus from the result of this study it can be presumed that only one stone characteristic approach may be sufficient to estimate other characteristics in Rubus.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.370-377
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• 1989

Jerusalem artichoke (Helianthus tuberosus L.) as a biomass potential crop has several distinct advantages such as vigorous growth on poor land and high yield of carbohydrate. In this crop, seed dormancy has hampered the efforts of seed-propagration and to use them in breeding programs for improving jerusalem artichoke. Several seed treatments were tested to determine their effectiveness in overcoming the seed dormancy found in five collected varietes of jerusalem artichoke. The first results showed that the seed fertilities of five collected varieties ranged from 2.4％ to 14.7％ and the number of seed produced by one plant ranged from 88 to 1058. Germinability of seeds stored for 3 months at room temperature after harvest was almost 0％ and it was not improved by addition to the treatments of temperature, light and GA3, while germinability of seeds stored for 27 months at room temperature after harvest increased to 47.5％ in germination rate. But the removal and pin-pricking of seedcoat were very effective in breaking the seed dormancy, giving germination of 96.8％ and 82.3％, respectively. These results showed that the seed dormancy of jerusalem artichoke was induced by the seedcoat. Besides the treatment of seedcoat removal and seedcoat-pinpricking, the treatment of low and wet stratification was also effective in breaking the seed dormancy of jerusalem artichoke. Whole dormant seeds incubated for 70 days in low and wet condition germinated over 85％.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.85-93
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• 1984

This research was carried out to study the seed dormancy of radishes which were used for summer vegetation. The differences of dormancy of cultivars, maternal effects, the effect of full day length to mother plants, and the effects of chemical treatments for breaking the seed dormancy were considered for this study. These results sere summarized as follows; 1. The germination percentage of 7 cultlvars sown just after harvest were as follows;SP70-:0, PS11-:37.5, GJ75-:75.5, JD127-:77.5, YH85-:81.0, M55-:96.5, and JC73-:98.0%. 2. The dormany of $F_1$ seed of radish was severe when SP70-was used for mother plant. 3. Germination behavior was different by the maturity of plants grown for seed production. The dormancy of seed harvested from immature field-grown plants sown Nov. 10 was deeper than mature plants sown Mar. 22. 4. The germination ratio of tire seed of SP70-radish was increased by treatment of full day length to tire mother plant during full period of growing or since first flowering stage, while that was 0% by treatment since yellow ripening stage. 5. GA 200 ppm+thiourea 0.2% treatment was most effective for breaking of radish seed dormancy.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.254-262
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• 2019

Background: To exploit the ornamental and medicinal purposes of Lonicera harae Makino, L. subsessilis Rehder, L. praeflorens Batalin, and L. insularis Nakai, native to Korea, it is necessary to understand their seed ecology for propagation. In this study, we investigated the seed dormancy type and germination characteristics of seeds of the four Korean native Lonicera species. Results: The seeds of the four Lonicera species imbibed water readily, suggesting that the species do not have physical dormancy. Furthermore, the seeds exhibited underdeveloped embryos with only about 15-25% of the length of the seeds at dispersal. The embryos grew to the critical length with approximately 50-80% of the length of the seeds' development before radicle protrusion. Further, 94.4% and 61.1% of freshly matured seeds of L. insularis and L. harae germinated within 4 weeks after sowing at 15 ℃ and 20 ℃, respectively. Contrarily, L. praeflorens and L. subsessilis seeds did not germinate within 4 weeks under all temperature treatments. At 15 ℃, L. praeflorens seeds started to germinate from 5 weeks and the final germination rate was 51.1% at 13 weeks. At 15 ℃, L. subsessilis seeds started to germinate from 5 weeks after sowing and the final germination rate was 85.6% at 17 weeks after sowing. Embryo growth and germination of L. praeflorens and L. subsessilis occurred at a relatively high temperature (≥ 15 ℃). Conclusions: Overall, L. insularis seeds have only morphological dormancy. The seeds of L. harae have approximately 60% and 40% of morphological dormancy and morphophysiological dormancy, respectively. Contrarily, L. praeflorens and L. subsessilis exhibited non-deep simple-type morphophysiological dormancy that requires relatively high temperature (≥ 15 ℃) for embryo growth and dormancy breaking. The optimum temperature for the germination of seeds of L. insularis, L. harae, L. praeflorens, and L. subsessilis was 15 ℃, 20 ℃, 15 ℃, and 20 ℃, respectively. There was interspecific variation in seed dormancy and germination patterns in the four Lonicera species. The difference in these characteristics within the four Lonicera species could be useful for understanding the seed ecophysiological mechanisms of Lonicera species.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.102-109
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• 1986

To know the ecological pattern of bulrush (Scirpus juncoides) seeds in dormancy-breaking responses as affected by different ripening processes, storage conditions, germination conditions, and some of known chemicals concerned, the study was conducted. Among other conditions detected, the burial in 2 cm depth paddy soil, $5^{\circ}C$ storage temperature, pre-maturing process (Green color), high concentration of chemicals used, and flooding paddy surfaces were the most efficient conditions for bulrush seeds to break dormancy and germinate, respectively.

• Korean Journal of Medicinal Crop Science
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• v.7 no.1
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• pp.16-21
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• 1999

Seed-propagation of Solomon's seal (Polygonatum odoratum) takes 2 years to shorten the period for becoming a practical method. The experiment was done to establish a proper method of breaking the epicotyl dormancy in bulk seed-propagation. Seedlings with a bulbil were treated with $GA_3$ every 2 days for 4 or 8 days and chilling treatments at $3^{\circ}C$ were enforced for 4, 6, 8 or 12 weeks. Emergence- and growth-related characteristics were examined immediately after the treatments, 3 and 6 weeks later. Rate of cotyledonary sheath rupture immediately after $GA_3$ treatment was greater in its 8-day treatment than in 4-day although its effect disappeared later. However, any epicotyl treated with $GA_3$ solution did not elongate so that new seedlings disemerged over the bed soil. That resulted from not breaking the epicotyl dormancy since $GA_3$ did not rupture all of the cotyledonary sheath formed with several sheets and consequently, the solution did not reach it. The $GA_3$ treatment for bulk seed-propagation, therefore, was impractical method. On the contrary, the chilling treatment was able to be applied to the seed-propagation because of getting the cotyledonary sheath rupture and the epicotyl elongation. Seedling emergence and its growth after chilling treatment were influenced by chilling period although required at least over 6-week treatment for satisfactory results.

• Journal of Sericultural and Entomological Science
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• v.35 no.2
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• pp.79-85
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• 1993

Winter dormancy of the mulberry(Morus species) in Suwon was investigated with regards to mulberry varieties, such as Kaeryangppong, Daeryunppon, Yongchionppong and Hongolppong application of fertilizers and growth hormone. In general, It initiated at late September and it subsequently became deeper and reached the highest degree through late October to early November. After that early November it gradually turned into the breaking state and was terminated by late November. Intensity and duration of dormancy were lower and shorter in Kaeryangppon. The standard application of N. P. K(30-13-18kg/10a) affects it delayed, but terminated earlier. On the other hand, the double amount of nitrogen affects the dormancy fast, but terminated late. The treatments of GA3 at the early and termination stages increased the bad sprouting. The contents of RNA and protein in the bark gradually increased as the dormancy becomes deeper.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.64-67
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• 1996

This experiment was carried out to obtain the information on seed dormancy, germinability during storage in wasabia japonica Matsum. $GA_3$ 100ppm+BA 10ppm was more effective than $GA_3$100ppm alone in breaking the dormancy. Storage of seeds pretreated with growth retardants (CCC, Uniconazol) seemed to be a useful method for preventing germination during storage. The stratification was an effective storage method to germinate the seeds for sowing them in fall.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.61-66
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• 2002

Double cropping system in a year in Kyoho grapes (Vitis labruscana L.) has currently been attempted in the plastic greenhouse. One of the problems in double cropping system is the promotion of bud break in summer season and shoot fertility. Effects of the control of soil moisture tension near the root zone and treatments of bud dormancy breaking agents on bud breaking in summer were examined to promote the bud break for the second fruiting. The lignification of shoots was induced in July or August by the control of soil moisture tension in root zone environment. The first shoot growth was almost the same as that in common plastic greenhouses. The highest bud break value appeared in the plot of cyanamide chemicals mixed with merit blue as over 75% bud break rate. The bud break rate in the discontinuing plot in irrigation showed significantly higher in bud break than that in the continuing plot in irrigation. Despite of the final high bud break rate, the time of bud break was irregular.