• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.384-389
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• 2009

Germination characteristics of Chinese milk vetch(CMV) seeds produced from Hanam Province, China and Milyang, Korea were investigated to give basic information on the stability of seedling establishment in the CMV cultivation. The germination percentage of the imported CMV seed from China varied according to importation year and seed collection site ranging from 79~95%. The germination of black colored seed coat was lower than the light green colored ones and germination by seed weight was not significantly different. Although the seed germination was lower under dark than in the presence of light, it was not significantly different. The germination of the imported CMV seed slightly declined to only less than 6% after one-year of storage under natural environment conditions but it significantly decreased after two years. However, when the seed was stored at the $5^{\circ}C$, the seed germination was the same as after two years of storage. On the other hand, fresh CMV seed produced in Milyang, Korea had only 8% germination due to seed coat dormancy but the germination increased to 73~85% after breaking seed dormancy after a year of storage. The high germination percentage of 72~82% was still maintained even after 27 months of seed storage unlike the CMV seed produced from China. These results indicate that CMV seeds do not require light for germination and the seed from China should be used within one-year after importation while the seeds produced from Korea can be used even after two years from harvest for stable CMV seedling establishment in the CMV-rice cropping system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.308-314
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• 2011

Seed germination and dormancy of three green manure seeds such as hairy vetch, crimson clover and narrow-leaved vetch (Vicia angustifolia L.) produced in Milyang, southern part of Korea were investigated to provide a basic information on the stability of seedling establishment in green manure seeds. In addition, the effect of seed storage duration on the germinability of imported hairy vetch and crimson seeds was also investigated. To determine the seed maturity time of three green manure seeds, the seeds were harvested manually at May 25, May 30, and June 4, and the 100-seed weight, germinability and percentage of hard seed were evaluated. Freshly harvested seeds of three green manure crops were strongly dormant because of hard seed coat. Germination percentage of the three green manure crops varied depending on the seed harvest time ranging from 30 - 52% in hairy vetch, 16 - 35% in crimson clover and 2 - 61% in V. angustifolia, respectively. Of the three crops, crimson clover and V. angustifolia matured early on May 30 to June 4 (around 35 to 40 days after flower) but hairy vetch seed did not mature until June 4 based on the seed germinability. The matured seed of crimson clover and V. angustifolia germinated less than 20% while scarification on seed coat significantly overcome the innate dormancy. On the other hand, the seed germination of hairy vetch and crimson clover was lower under dark than in the presence of light. The germination percentage of the imported hairy vetch and crimson clover seeds showed high with 77 - 79%, 94 - 95%, respectively, but the seed germination significantly declined by 21 - 32%, 30 - 40% after one-year of storage under natural conditions. The seeds germinated only 8 - 13% for hairy vetch but crimson clover did not germinate at all after two years storage. These results indicate V. angustifolia and crimson clover mature at May 30 to June 4 but hairy vetch did not. The imported hairy vetch and crimson clover seeds should be used within one-year after import for stable seedling establishment in green manure-rice cultivation cropping system.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.268-278
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• 2020

Flowering time has been put forward due to the recent abnormally warm winter, which often caused damages of flower buds by late frosts persistently. In the present study, cumulative chill unit and cumulative heat unit of Niitaka pear, which are required for releasing the endogenous dormancy and for flowering after breaking dormancy, respectively, were compared between flowering time prediction models used in South K orea. Observation weather data were collected at eight locations for the recent three years from 2018-2020. The dates of full bloom were also collected to determine the confidence level of models including DVR, mDVR and CD models. It was found that mDVR model tended to have smaller values (8.4%) of the coefficient of variation (cv) of chill units than any other models. The CD model tended to have a low value of cv (17.5%) for calculation of heat unit required to reach flowering after breaking dormancy. The mDVR model had the most accurate prediction of full bloom during the study period compared with the other models. The DVR model usually had poor skills in prediction of full bloom dates. In particular, the error of the DVR model was large especially in southern coastal areas (e.g., Ulju and Sacheon) where the temperature was warm. Our results indicated that the mDVR model had relatively consistent accuracy in prediction of full bloom dates over region and years of interest. When observation data for full bloom date are compiled for an extended period, the full bloom date can be predicted with greater accuracy improving the mDVR model further.

• Korean Journal of Weed Science
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• v.9 no.2
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• pp.116-122
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• 1989

An experiment was carried out at the International Rice Research Institute in 1987 to understand the seed dormancy and germination habit of rice and several weed species. The germinability of the weed seeds just after harvest was variable depending on the species and ranged from 0 to 72%. Two rice cultivars, IR64(lowland type) and UPLRi-5(upland type) had higher than 95% in germination ability throughout the experimental period due to the fact that the rice seeds came from the harvest of the previous season and dormancy had already been overcome. The length of the storage period needed to overcome dormancy at room temperature($25{\pm}2^{\circ}C$) was about 50 days for Echinochloa glabrescens Munro ex Hook, f., more than 60 days for E. crus-galli ssp. hispidula (Retz.) Honda and 20 days for Ludwigia octovalvis(Jacq.) Raven. Seeds of E. colona(L.) Link, Monochoria vaginalis(Burm. f.) Presl, Fimbristylis miliacea(L.) Vahl and Cyperus difformis L. appeared to have no dormancy. Among the nine species M. vaginalis had the lowest germination of less than 1% throughout the experimental period. However, its seed germinated easily when planted in soil. The low germinability of E. glabrescens, E. crus-galli ssp. hispidula and L. octovalvis just after harvest could be overcome through pretreatment of seeds either by soaking in nitric acid(0.1N) for 1 day or removal of the hull in the grass species, the nitric acid treatment being superior. The results imply that germination habit of weed species varied depending on the species through their differential dormancy period or differential germination strategy.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.7-12
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• 1986

This experiment was conducted to investigate effects of different water depths on emergence, emerged soil depth and growth of E. crus-galli in Seoul, Korea. Plant number of emergence was decreased with deepened water depth, and dry weight of plant was especially negatively affected. However, a few E. crus-galli were emerged under 24 cm water depth. Soil depth of germination was increased as water depth decreased, and a few E. crus-galli were emerged below 10 cm soil depth under - 12 ㎝ water depth. But most E. crus-galli were emerged in ca. 2 cm soil depth under water depth over 0 cm.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.308-319
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• 2016

The purpose of this study is to identify distribution patterns of hydrophytes in the Mokpo wetland in relation to the depth of water. Sample surveys were conducted based on plant species distribution status and water depths at 274 spots. This study also developed a detailed depth distribution map for Mokpo wetland, which was never done in any previous studies. Through this study, it was found that the average depth of the wetland was 77cm (${\pm}29cm$) and the maximal depth was 157cm. The outer edge was no deeper than 60cm and the center approximately 120~130cm in depth, forming a concave bowl-like shape. This research confirmed inhabitation of 6 types of submerged plants (Verticillate hydrilla, Vallisneria natans, Najas graminea, Potamogeton cripus, Ceratophyllum demersum, and Potamogeton brechtoldi), and three types of floating leaved plants (Euryale ferox, Hydrocharis dubia and Trapa japonica) in the surveyed areas of the wetland. The distribution of these hydrophytes showed a statistically significant difference (${\chi}^2=982.2$, df = 8, p < 0.01), which confirms the fact that distribution varies based on environmental conditions. The most frequently observed species was Trapa japonicas at 244 times, and it showed a distribution pattern by which coverage increased with greater depth, as was also seen in the case of Potamogeton cripus. Five species-Euryale ferox, Hydrocharis dubid, Verticillate hydrilla, Najas graminea, and Ceratophyllum demersum-showed a negative correlation to depth, by which coverage decreased with increasing depth. It has been shown that fundamentally, the distribution of hydrophytes based on depth is affected by ecological factors, but also reflects the environmental properties of Mokpo wetland.

• Journal of Bio-Environment Control
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• v.21 no.1
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• pp.45-49
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• 2012

Chilean wild flower seeds showed low germination rate and lacked germination uniformity. This experiment was conducted to find out the effects of light conditions, $GA_3$ (50 mg/L, 100 mg/L, 200 mg/L) and $KNO_3$ (0.1%, 0.2%, 0.4%) treatments on germination of five species of Chilean wild flower seeds. The seeds of $Schizanthus$ $candidus$, $Schizanthus$ $hookerii$, and $Schizanthus$ $litoralis$ did not germinated in light condition. The others did not show a significant different germination rate under light and dark conditions. The germination rate of $Mimulus$ $luteus$, $Schizanthus$ $candidus$, $Schizanthus$ $hookerii$ increased 2.3, 5.6, and 3.2 times compared with control, respectively in $GA_3$-200 mg/L treatment, but that of $Rhodophiala$ $ananuca$ enhanced slightly in $GA_3$-50 mg/L treatment. Those results suggested that the germination rate of Chilean wild flower seeds enhanced by $GA_3$ treatment that is very efficient in breaking seed dormancy.

• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.102-107
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• 1998

Solomon's seal (Polygonatum odoratum) seedlings raised through its seeds can replace the rhizomes impelling higher cost for transplanting, This experiment was done to determine the seed characteristics and the germinating processes to give some information on bulk production of seedlings using the seeds. The external or internal morphology of seeds or seedlings grown in lab. or greenhouse was examined mainly with stereomicroscope. The external shape of Solomon's seal seed was hard seed-coat and orthotropous ovule with linear type embryo stretching to the center of seed. Germination proceeded through the several steps. The lower part of seed embryo having the primordia of bulbil and roots first grew before the bulbil and roots was developed from the primordia. The lower part of embryo was enlarged toward the endosperm of seed as soon as seed germinated. Then epicotyl was formed on the apex of bulbil. The epicotyl was elongated after at least 6-week chilling treatment for breaking its dormancy and the first leaf shape was affected by light intensity given during seedling emergence. The bulbil was the first organ of the rhizome used as tea or herb medicine.

• Korean Journal of Medicinal Crop Science
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• v.11 no.3
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• pp.207-211
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• 2003

This experiment was carried out to investigate the effects of $GA_{3}$ and cold stratification as presown treatments on seed germination, seedling emergence and final survival rate of Acanthopanax senticosus Maxim. Seeds collected 145 days after-ripening period followed by 10 days of cold stratification was effective in promoting germination. Dehisced seeds treated with 500 ppm of $GA_{3}$ for 3 days was also effective in promoting germination. However, seedling emergence rate remained low in both treatment. Seedling emergence rate was higher for seeds germinated in Heungnong-Bio and Klasman-Bio than in vermiculite, perlite, vermiculite-perlite mixture, or sand. After 40 days of cold stratification, seedling emergence was significantly higher in the 500 ppm $GA_{3}$ treatment than nontreatment for both dehisced and non-dehisced seeds. However, for dehisced seeds, $GA_{3}$ treatment before sowing resulted in decreased final seedling survival rate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.146-157
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• 1994

Wasong(Orostachys japonicus A. Berger) has been used as anti-cancer medicinal plants from ancient time. This experiment was conducted to obtain some fundamental informations concerning anatomical study, germination test, soil analysis of indigenious districks, adaptaion of soil for wasong. The leaf of wasong was xerotype with spine, mesophyl chloroplast is dense surrounded vascular bundle, with a many large water storage tissue without chloroplast, and was bifacial stomata leaf type. The stem of wasong was amphicribral vascular bundle, central cylinder was cylinder type and protostele. Root was polarch type, potoxylem of it's was arranged in ring shape of annulation and metaxylem. The structure of flower was cymose, was caylyx of 5 sepals, corolla of 5 petals, roecium of 10 stames, ovules of five, placentation parietal, ovary superior, axile placenta. The optimum temperature for seed germination was $25^{\circ}C$ under light and germination percentage was 22.5%. Dormancy breaking was effective for 6-8 days at 5$^{\circ}C$ and at 100 ppm level of $GA_3$ The soil analysis of wasong local districks, content of available $P_2O_5$, Ca were higer than optimal level of upland and C.E.C., exchangeable k was not significantly different of that, but exchangeable magnesium was very low. The growth of wasong was affected draining regardless soil combination treatment.