• Korean Journal of Environment and Ecology
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• v.14 no.3
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• pp.199-204
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• 2000

최근 자연생태계에서 일어나고 있는 자생 민들레류의 감소와 서양민들레의 급속한 증가원을 종자 발아특성을 통해 알아보고자 한다. 각각의 종자는 무처리를 비롯하여 10일, 20일, 30일, 60일간의 저온처리를 실시하였으며 발아조건은 광조건과 암조건으로 실험하였다. 자생민들레의 경우에 광조건하의 무처리 대조구에서 28%의 발아율을 나타내었으나 60일간의 저온처리구에서 90%의 발아율을 나타내었다. 발아세와 평균발아기간도 30일 이상의 저온처리와 광조건하에서 양호한 성적을 나타내었다. 좀민들레의 경우에도 민들레와 거의 유사한 경향을 나타내어 30일 이상의 저온저리와 광조건하의 발아상태가 대조구에 비해 상대적으로 양호하였다. 그러나 서양민들레는 저온무처리구의 광조건에서 발아율 88.8%로 자생 민들레류에 비해 현저히 높게 나타났다. 또한 서양민들레 종자는 저온처리에 의핸 현저한 발아율 향상을 볼 수 없었다. 그러므로 30일 이상의 저온처리에 의해 휴면이 타파되고 발아율이 향상되는 자생 민들레류의 비휴면성인 성양민들에 비해 종 번식에 있어 상대적으로 불리하다는 것을 알 수 있었다.

• Korean Journal of Breeding Science
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• v.43 no.4
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• pp.288-296
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• 2011

To clarify the seed germination characteristics among cultivated Perilla crop and their weedy types in Korea, we studied the germination percent and germination energy of 162 accessions (102 cultivated var. frutescens, 41 weedy var. frutescens, and 19 weedy var. crispa) in both conditions of $4^{\circ}C$ low temperature treatment and non-cold treatment. In our study, most accessions of cultivated var. frutescens showed more than 50% in both germination percent and germination energy in both cold and non-cold treatment conditions. Whereas, most accessions of weedy var. frutescens and weedy var. crispa showed lower than 50% in both germination percent and germination energy in both cold and non-cold treatment. In addition, most accessions of Perilla crop and their weedy types showed much higher germination percent and germination energy in $4^{\circ}C$ low temperature treatment condition compared to the seeds under non-cold treatment condition. The information provided in this research may help for our understanding the variation of seed germination characteristics among accessions of cultivated Perilla crop and their weedy types in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.31-38
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• 1980

This experiment was carried out to study the heterosis and the GCA and SCA effects for days to heading of F 1 populations produced from eight wheat cultivar diallel. Greater heterosis for early heading was exhibited under the high temperature condition than under the low temperature conditions, and same results were also observed under short day condition rather than long day conditions. There are highly significant mean for GCA and SCA at all environmental conditions. Yecora F70 was showed the greatest effect, and Bezostaya and Blueboy were exhibited less effects of CCA for early heading. Significant GCA effect was expressed at high temperature and short day condition, indicating that this condition provides a better opportunity to select the materials for earliness. Selections of combination with greater effect of SCA for early heading such as Suweon 169 \times Yecora F70 were discussed for practical utilization.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1452-1460
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• 2013

The purpose of this study was to investigate secondary drying effects on garlic quality, and to define the optimal secondary drying conditions for garlic preservation. The secondary drying tests used garlic that was naturally dried once and stored at low temperature. After secondary drying, the garlic was stored in a warehouse at room temperature. Tests were performed at different low-temperature storage periods (60, 105, 150, 195, and 240 days), secondary drying temperatures (35 and $40^{\circ}C$), drying times (1, 2, 3 days), and room temperature storage periods (15, 30, and 45 days). The results were compared with a non-secondary drying condition control. In general, the $40^{\circ}C$-2 days dry conditions showed the lowest weight-loss rate (5%) and rotting rate during room temperature storage. The sprouting rate increased by 20% during the initial 15 day-room temperature storage, along with a small increase after 30 days of room temperature storage. Increases in drying temperature and the period of secondary drying conditions caused a decrease in firmness. In addition, the sprouting rate was 10% higher, and rotting rate 5~10% higher, for the non-drying condition, compared to drying conditions. Based on our results, the $40^{\circ}C$-2 days drying condition is the optimal secondary drying condition for garlic storage.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.262-266
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• 2009

Plant growth-promoting rhizobacteria (PGPR) are beneficial native soil bacteria that colonize plant roots and result in increased plant growth. The objective of this study was to determine the plant growth promotion in canola plants by selected PGPR strain 13-1 under low temperature condition. The seed treatment of strain 13-1 was enhanced plant height and root elongation on canola plant at low temperature condition. This result determined that a selected strain of PGPR can enhance plant growth and root propagation under extremely low temperature conditions. Thus, this PGPR strain extends their role on plant growth promotion on canola until low temperature condition for practical applications.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.128-135
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• 2011

In this study, in order to develop ultra rapid hardening mortar(URHM) for tunnel repairs using bottom ash of low recycle ratio and Admixture as Eco concept, fundamental properties of URHM on temperature condition of construction field were performed. Test result, URHM of three types for fluidity and setting time were as in the following : B > C > A. Those for low temperatures were later than the standard condition. Compressive, bending and bond strength were similar with three types as follow. In compressive strength, initial strength of the low were smaller than the standard but the low in the long-term were similar with the standard. On the contrary to this, bending strength were similar in initial strength but the low in the long-term were smaller than the standard. The low in bond strength was average 35% less than the standard. Length changes was as in the following : A > C > B. the low is two times much as the standard but the case using blast furnace slag particles noticeably reduced length changes. Water absorption coefficient and water vapor resistance were as in the following : C > A > B. In case of URHM added bottom ash, water absorption coefficient and water vapor resistance were increased because bottom ash is porous material.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.308-313
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• 1995

In relation to shortening generation by using embryo culture of barley immature seed, it is important to find out profitable embryo age for embryo culture and to understand the relationship among embryo and other characters. Two varieties(Olbori and Dusan #12) were cultivated under two growth conditions(15/10 and 25/15$^{\circ}C$). The embryos were aseptically excised when immature seeds were collected 9, 13, 17, 21, 25 and 29 days after heading and cultured on $B_5$ medium. On the 21st day after heading, the length of embryos from top or middle part of spike was longer than that from bottom part. Embryos from bottom part under low temperature condition had the shortest length. Shoot length, root length and root number after embryo culture were little difference among three parts of spike under high temperature condition. Under low temperature, seedlings from bottom part of spike were inferior to those from top or middle part. Length of 29-day-old embryos under low temperature condition was similar to that of 17-day-old ones under high. Under high temperature condition, the length of 17-day-old embryo had positive correlation with kernel width, shoot length, root length and root number, but that of 21-day-old one didn't have. Seventeen-day-old embryos obtained from 25/15$^{\circ}C$ growth condition seem to be efficient to shortening generation by using embryo culture.

• Superconductivity and Cryogenics
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• v.11 no.1
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• pp.31-37
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• 2009

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.711-715
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• 1995

This study was carried out to determine the desirable screeing condition for low-temperature germinability of rice seeds. The germination test was performed with fifty rice varieties from three countries, mainly including the recent Korean rice cultivars. The analyzed result of germination test under three temperature conditions(13$^{\circ}C$, 16$^{\circ}C$, $25^{\circ}C$) pointed out that 11 days after seeding at 13$^{\circ}C$ was the most efficient testing condition for low-temperature germinability in terms of mean and variation in germination rate. Highly significant correlations were observed between germination rates of 11 days after seeding at 13$^{\circ}C$ and germination coefficients, average days of germination at 13 for 20 days. Low-temperature germinability were highly positively associated with days to heading or amylose content, but negatively correlated with grain width.