• 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.

• Korean Journal of Breeding Science
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• v.42 no.2
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• pp.144-150
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• 2010

The objective of this study was to map gene/QTL for photoblastism in a weedy rice (photoblastic rice: PBR) using DNA markers. Light-induced effect on germination of seeds was compared among three accessions (Oryza sativa L.), PBR, Milyang 23 and Ilpum. Results showed that PBR seeds started to show photoblastism during seed development, different from Ilpum and Milyang 23. Frequency distribution of germination in the F4 lines from crosses between Ilpum and PBR and, Milyang 23 and PBR revealed bimodal distributions suggesting that photoblastism was controlled by a few genes. Bulked segregant analysis using $F_4$ populations derived from the above two crosses was conducted to identify gene/QTL for photoblastism. Two QTL were identified on chromosomes 1 and 12 explaining 11.2 and 12.8% of the phenotypic variance, respectively. Two QTL were further mapped between two SSR markers, RM8260 and RM246 on chromosome 1, and between RM270 and 1103 on chromosome 12. It is noteworthy that two QTL for photoblastism were colocalized with the QTL for seed dormancy reported in the previous QTL studies. The clustering of two genes for photoblastism and dormancy possibly indicates that these regions constitute rice phytochrome gene clusters related to germination. Because PBR has a low degree of dormancy, a pleiotropic effect of a single gene controlling dormancy and photoblastism can be ruled out. The linked markers will provide the foundation for positional cloning of the gene.

• Journal of Environmental Science International
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• v.30 no.1
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• pp.77-85
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• 2021

This study was carried out to establish optimal conditions for breaking dormancy of Agastache rugosa O. Kuntze seeds. A series of experiments according to seed maturity and treatment with plant growth regulators were performed to improve germination percentage and synchronize germination of the seeds. In addition, it was conducted to test whether the useful effect of seed treatment before sowing leads to healthy seedling and early vigorous growth. The average seed size was 1.85 mm (length) × 0.82 mm(width). The seed size was much smaller than other vegetable seeds. Seeds colorappeared dark brown, the shape of the seeds was oval and the weight of 1,000seeds was 352.8 mg. The optimum germination temperature was 22℃. Light exposure during germination did not affect germination promotion, suggesting that A. rugosa seeds are a kind of dark germinating seeds. Seed dormancy lasted for 40 days after harvesting, and GA3 treatment of dormant seeds could break dormancy. There were significant differences in germination percentage and rate according to the maturity of seeds. The germination percentage of mature seeds was 10 - 18% higher than that of immature seeds, and germination rate was 2 days faster. GA3 treatment during growth regulator treatment improved germinability, but BAP or ethephone treatment did not. The optimal growth regulator concentration of for germination was the combination treatment of 100 mM GA3 ＋ 100 mM BAP.

• BMB Reports
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• v.56 no.9
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• pp.482-487
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• 2023

Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we describe the role of KAI1, which is mainly expressed on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs), in niche-mediated LT-HSC maintenance. KAI1 activates TGF-β1/Smad3 signal in LT-HSCs, leading to the induction of CDK inhibitors and inhibition of the cell cycle. The KAI1-binding partner DARC is expressed on macrophages and stabilizes KAI1 on LT-HSCs, promoting their quiescence. Conversely, when DARC+ BM macrophages were absent, the level of surface KAI1 on LT-HSCs decreases, leading to cell-cycle entry, proliferation, and differentiation. Thus, KAI1 acts as a functional surface marker of LT-HSCs that regulates dormancy through interaction with DARC-expressing macrophages in the BM stem cell niche. Recently, we showed very special and rare macrophages expressing α-SMA+ COX2+ & DARC+ induce not only dormancy of LT-HSC through interaction of KAI1-DARC but also protect HSCs by down-regulating ROS through COX2 signaling. In the near future, the strategy to combine KAI1-positive LT-HSCs and α-SMA/Cox2/DARC triple-positive macrophages will improve the efficacy of stem cell transplantation after the ablative chemo-therapy for hematological disorders including leukemia.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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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.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.200-209
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• 1996

It is assumed to be an efficient method for keeping a germinability of weed seeds as long as possible, if a secondary dormancy is not induced by transferring the seeds of which dormancy was broken in wetting condition into drying condition. To investigate its validity, two experiments were carried out on seeds of 9 weed species ; to find out the most effective storage condition in breaking the dormancy of each weed species and to know whether there is a decrease in the germinability by transferring into drying storage condition. The dormancy of Chenopodium album and Stellaria aquatica was released well under the drying condition, but that of Echinochloa crus-galli var. oryzicola by soaking in water. Other weed species were released from dormancy by storage in wetting condition. When the seeds stored in the wetting or soaking condition, are air-dried and then restored at room or low temperature, a decreasing tendency of germinability which might cause a trouble in using them practically, was not observed except on the seeds of Persicaria vulgaris. In the case of Persicaria vulgaris, the low germination since 3 month-storage seemed not to be caused by drying, because a decrease of its germinability was observed with increasing storage period in all of the storage conditions. In contrast, high germination was induced as the seeds of Echinochloa crusgalli var. oryzicola, which were not germinated during the storage in low temperature and wetting condition, were transferred into the room temperature and drying condition. These results suggest that this approach can be one of the efficient methods for keeping a good germinability as long as possible in most weed seeds.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.443-447
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• 2014

Triploids have several potential advantages over diploids in aquaculture, drawing an elevated commercial reaction into the realistic application of the techniques despite we are still in the early stage of triploid industry for the Pacific oysters Crassostrea gigas. We traced the growth performance of the triploid C. gigas for over a year from hatchery spats, which was created by manipulations of chemicals (Cytochalasin B, CB or 6-Dimethylaminopurine, 6-DMAP). The growth was clearly marked by an initial longer dormancy and following a great magnitude of heterogeneity. The dormancy was almost 9 to 10-month long or even longer and was considered as a downside of the creation. The heterogeneity was magnified by appearance of extraordinarily growing oysters in part during summer season, which could be a representative upside of the triploids. Overall, however, the results were not as positive as were expected. The longer dormancy and following heterogeneity observed in our practice could be marked as an additional negative sign of the chemical use. The present study, thus, might be highly indicative in the introduction of biological cross between tetraploid and diploid to produce natural triploid embryos.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.45-51
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• 1977

The studies were carried to know the effects of GA$_3$, Ethrel and $H_2O$$_2$ on dormancy and germination in ginseng seeds. GA$_3$ stimulated the embryo growth and increased dehiscent (Kaekapp) ratio of the seeds for more than Ethrel and $H_2O$$_2$ GA$_3$ not only increased germination ratio but also shortened the period of germination. Ethrel and $H_2O$$_2$ showed no effects on the germination and there were no significant differences among the treatment levels of GA$_3$. The slow germination of ginseng seeds seemed to be mainly due to the dormancy of endosperm or seed coat rather than of embryo.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.269-273
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• 2007

Freezing hardiness of winter bud and branch according to dormancy level and low temperature, in persimmon (Diospyros kaki) cultivars, was investigated by electrolyte leaching rate, triphenyltetrazolium chloride (TTC) test, and sprouting. Electrolyte leaching rate was lowest in branch of 20th January and was highest in the 20th March. The electrolyte leaching rate of 'Fuyu' and 'Cheongdobansi' was high in the 20th January and was low in the 20th February, but 'Uenishiwase' and 'Nishimurawase' was opposed to that. 'Hachiva' was the middle level in the cultivars. Absence rate by TTC test was highest in the 20th January and was low in the others. The 20th March had a great decrease in $-10^{\circ}C$ treatment. The absence rate of 'Fuyu' and 'Uenishiwase' was low in the 20th January and March and was high in the 20th February. 'Nishimurawase' and 'Hachiya' had a high level irrespective of dormancy level. Sprouting was highest in the 20th February and was lowest in 20th March. Most cultivars were not sprout in $-20^{\circ}C$ treatment and 'Fuyu', 'Nishimurawase' and 'Cheongdobansi' was a little high level irrespective of dormancy level. 'Hachiya' was only high in the 20th January. Thus, freezing hardiness of persimmon was very weak low temperature after dormancy breaking and was not different between astringent and non-astringent persimmon.

• Korean Journal of Weed Science
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• v.18 no.4
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• pp.295-303
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• 1998

The seed dormancy is one of the peculiar characteristics of a number of weed species and it makes difficulties in weed control. To clarify the mechanism of seed dormancy, several chemicals such as $KNO_3$, KOH, thiourea, and $H_2O_2$ and phytohormone($GA_3$) were treated to dormant seeds. Among the species treated with several chemicals, the germination percentages of Setaria glauca, Ambrosia trifida and Ranunculus sceleratus were increased with $KNO_3$ and those of S. glauca, R sceleratus were increased with thiourea. Hydrogen peroxide promoted the germination of Setaria viridis and S. glauca. Germination percentages of S. viridis, S. glauca and Cyperus saraguinolentus were increased with enzyme treatment using pectinase. GA treatment enhanced the geim.ination of Eleusine indica and R sceleratus but the other species were affected slightly. Especially. E. indica showed linearity in the relationship between germination percentage and GA concentration. So, It seemed that E. indica can be used as a bioassy material for GA. Considering the phenological habits of weed species, the seeds were buried under soil for long time(more than 1 month) over winter. When seeds were buried in soil, the degree of dormancy was drastically decreased. Especially, germination of seeds buried were increased under alternating temperature. The germination rates of Persicaria ssp. and Chenopodium ssp. were increased by 50% order alternating temperature after burial for seven weeks.