• Journal of Bio-Environment Control
• /
• v.19 no.4
• /
• pp.377-381
• /
• 2010

This study was carried out to access the stauts of pyruvic acid and sugars in onion bulbs during storage at room temperature. Pyruvic acid content remained in a steady state until 3 months of storage. However the pyruvic acid content gradually increased as the onions started to root, and rapidly increased after sprouting. There was no difference in dry matter contents during storage.e. Sucrose content increased as storage duration extended, and then gradually decreased right after the onions started to sprout. Fructose content gradually decreased after 45 days of storage, and remained in a steady state after sprouting. Glucose content had a tendency to increase as storage duration extended. Pyruvic acid/total sugar (PA/TS) ratio decreased after 1 month of storage, and then increased after 135 days, and was 83% higher at 150 days of storage than at harvest. Sweetness gradually decreased until 1 month of storage, but thereafter remained steady. Therefore it is desirable that pyruvic acid analysis for sweet onion selection should be conducted before breaking the dormancy.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.7 no.4
• /
• pp.289-295
• /
• 2005

This paper reports on the dendrochronological investigation of tree ring growth of Pinus densiflora in the Gyeongbuk region. Tree ring growth was analysed using basic statistical value and correlation analysis to evaluate the relative contribution of climatic factors. Ta extract age-related trends and nonclimatic signals, each measurement series was standardized using a negative exponential growth function. In the Gyeongbuk region, tree ring growth was positively correlated with the current year in February, March and April, January, February, and March precipitation showed a positive correlation with the current growth year. This suggests that climatic factors (monthly average temperature, precipitation) limit breaking of dormancy and promotion of growth of Pinus densiflora in the Gyeongbuk region.

• Korean Journal of Plant Resources
• /
• v.19 no.1
• /
• pp.50-53
• /
• 2006

Nerine was originated from South Africa and around 30 kinds of species are distributed in worldwide. In present study we have characterized the condition of storage and growing conditions on the bulb propagation of Nerine by the tissue culture. Result indicated that the percentage of decrement, decay and sprouting of bulblets in the tissue culture was high at the higher temperature compare to lower temperature. The optimum conditions for storage and time were 12 weeks at $15^{\circ}C$ which were having 86.4% sprouting rate. The sprouting rate at different temperature and acclimation time, using bulblets in the tissue culture, were optimum at early June when temperature is relatively higher($22^{\circ}C$) that facilitate to breaking the dormancy. Growth characteristics and capacity of photosynthesis of Nerine were better at red and blue mixed lightness.

• Journal of Ginseng Research
• /
• v.40 no.4
• /
• pp.409-414
• /
• 2016

Background: The low survival rate of in vitro regenerated Panax ginseng plantlets after transfer to soil is the main obstacle for their successful micropropagation and molecular breeding. In most cases, young plantlets converted from somatic embryos are transferred to soil. Methods: In vitro thickened taproots, which were produced after prolonged culture of ginseng plantlets, were transferred to soil. Results: Taproot thickening of plantlets occurred near hypocotyl and primary roots. Elevated concentration of sucrose in the medium stimulated the root thickening of plantlets. Senescence of shoots occurred following the prolonged culture of plantlets. Once the leaves of plantlets senesced, the buds on taproots developed a dormant tendency. Gibberellic acid treatment was required for dormancy breaking of the buds. Analysis of endogenous abscisic acid revealed that the content of abscisic acid in taproots with senescent shoots was comparatively higher than that of taproots with green shoots. Thickened taproots were transferred to soil, followed by exposure to gibberellic acid or a cold temperature of $2^{\circ}C$ for 4 mo. Cold treatment of roots at $2^{\circ}C$ for 4 mo resulted in bud sprouting in 84% of roots. Spraying of 100 mg/L gibberellic acid also induced the bud sprouting in 81% roots. Conclusion: Soil transfer of dormant taproots of P. ginseng has advantages since they do not require an acclimatization procedure, humidity control of plants, and photoautotrophic growth, and a high soil survival rate was attained.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.4
• /
• pp.266-270
• /
• 2009

This experiment was conducted to investigate the effect of transfer date to a growth chamber and low temperature on growth and flowering of Jeffersonia dubia for free control of flowering period. According to transfer date, any plant did not sprout when plants were put in a growth chamber from Aug. 20 to Dec. 20. However, all the plants which were put in a growth chamber on Jan. 20 or Feb. 20 sprouted and resulted in flowering. The effect of beginning time and period of low temperature treatment were also observed. At the beginning time of Aug. 20, sprouting and flowering occurred as plant received more than 60 days of low temperature treatment. However, almost of al l the plants sprouted and flowered by only 30 days of low temperature treatment when the low temperature was given after Sep. 20. 60 days of low temperature given again after about three month growing period after dormancy breaking, resulted in resprouting of all plants and 70% of them flowered in this experiment.

• Journal of Plant Biotechnology
• /
• v.45 no.4
• /
• pp.347-356
• /
• 2018

Chionanthus retusus is a small deciduous tree that is widely used in landscaping due to its beautiful white spring flowers and ornamental value. Conventional propagation through seeds requires one to two years of breaking dormancy. The objective of this study was to determine the conditions of in vitro germination in C. retusus. In vitro embryo culture was carried out to investigate the effects of six factors: basal media (McCown Woody Plant Medium (WPM) and Murashige and Skoog (MS)); plant growth regulators (different combinations and concentrations of naphthaleneacetic acid (NAA), 6-Benzylaminopurine (BA), and gibberellic acid ($GA_3$)); embryo age (collected weekly beginning 36 days after fruit setting); low temperature pretreatment (storing $4^{\circ}C$ for 1, 2, 3, and 4 weeks); coconut additives (100, 200, and $300ml{\cdot}L^{-1}$); and genotype (grouping plants depending on their flowering nature). The basal medium used in this study was WPM with $2mg{\cdot}L^{-1-1}\;GA_3$, $20g{\cdot}L^{-1}$ sucrose, and $6g{\cdot}L^{-1}$ Agar. WPM medium mixed with $GA_3$, resulted in higher germination rate as compared to when using a combination of auxin and cytokinin. $GA_3$ at $2mg{\cdot}L^{-1}$ was the most effective of all combinations and concentrations of PGRs. WPM medium with $2mg{\cdot}L^{-1}GA_3$ resulted in better and faster germination (75.93%). Embryos collected at 57 days after fruit setting had the highest percent of germinated seeds (87.04%) while low-temperature pretreatment of fruits at $4^{\circ}C$ for two weeks produced the highest germination (95.37%). These results of this study could be an open ground for development of an efficient protocol for commercial production of the ornamental tree.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2023.04a
• /
• pp.10-10
• /
• 2023

투구꽃속(Aconitum L.)은 미나리아재비과(Ranunculaceae)의 가장 큰 속(Genus) 중 하나로 300-400 여종(Species)이 북반구 온대지역에 분포한다(Tamura, 1993). 둥근 투구모양의 꽃받침이 특징적이며, aconitine과 같은 알칼로이드 성분을 함유하고 있어 전통적으로 약용소재로서 활용되었다(Khorana, 1968). 세뿔투구꽃(Aconitum austrokoreense Koidz.)은 한국 경상도, 전라남도에만 국지적으로 자라는 한국 특산식물이자, IUCN에서 CR(Critical Endangered) 등급으로 지정된 희귀식물이다. 이 종은 다년생이지만, 서식지에서 개체수가 적거나 유묘의 발견이 어려운 등 자생지 축소 및 절멸의 우려가 높다. 세뿔투구꽃을 보호하고 종을 보존하기 위해서는 종자 발아 · 휴면에 대한 지속적 연구와 종자번식법의 개발이 필요하다. 본 연구에서는 세뿔투구꽃의 종자의 휴면유형을 분석하고 호르몬에 의해 휴면타파를 유도하였으며, 특히 발아 2단계에서 일어나는 생리적 변화를 단백질체학적 관점에서 분석하였다. 세뿔투구꽃 종자는 미발달된 배를 가지고 있으며, 충분한 수분과 온도의 조건에서도 발아가 관찰되지 않아 형태 · 생리적 휴면으로 판단되었다. 종자는 BAP 처리에서 휴면이 타파되는 것을 확인하였으며, 특히 BAP 농도에 따른 발아율은 통계적으로 유의한 값을 가졌다 (F=23.208, P<0.01). 건조된 종자에 비해 BAP 처리된 종자는 발아 2단계에서 몇가지 단백질의 증가가 관찰되었다. 대부분의 종자는 30S ribosomal protein subunit으로, 휴면상태에서 발아상태로 변환이 일루어지는 생리적 변화의 증거로 확인된다. 특히 발아2단계를 지나는 세뿔투구꽃 종자에서는 cytochrome subunit과 photosystem II protein의 급격한 증가가 관찰되었는데, 이는 배아의 발달 결과인 자엽이 발아 즉시 광합성이 가능하도록 준비하는 과정에서 발현 된 것으로 추정한다. 본 연구는 발아2단계에서 휴면타파에 직접적인 영향을 미치는 요인을 발견하지 못하였으나, 휴면타파에 중요한 단계인 발아 2단계 종자의 생리학적 변화를 이해하기 위한 기초자료로 활용 될 수 있을 것이다.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2023.04a
• /
• pp.23-23
• /
• 2023

The Hairy labrador tea (Ledum palustre L. var. diversipilosum Nakai) is a evergreen small shrub, belonging to the Ericaceae and mainly distributed along the alpine areas of Hamgyeong-do in North Korea. Through seed physiological research on North Korean plants, we intend to obtain basic data for the development of mass propagation methods and use them for vegetation restoration. The internal and external morphological characters of the seed were observed using scanning electron microscopy or stereoscopy, and full seeds were selected through X-ray test. Seeds were cultured on a growth condition at 15/6℃ and 25/15℃ to examine the germination response according to temperature, and the number of germinated individuals was examined every 24 hours to calculate germination percentage and mean germination time. Low-temperature treatment (4℃) and hormone treatment (GA3) were performed to investigate the effect of dormancy breaking, and analysis of variance (ANOVA) was performed on the experimental results using SAS 9.4. The seeds of the Hairy labrador tea were elliptical-narrow in shape, and the epidermal cell wall pattern was reticulated. The final germination rate (FGP) was the highest at 58.9% under the condition of low temperature treatment at 25/15℃. The average number of days to germination (MGT) was the highest at 25.1 days without treatment at 15/6℃, and the average of the last germination days was confirmed to be about 13 days. As a result of low temperature treatment, it was confirmed that the final germination rate (FGP) increased by 43.3%. The significance of the final germination rate (FGP) was verified according to the pretreatment at 25/15℃.

• Horticultural Science & Technology
• /
• v.17 no.2
• /
• pp.123-126
• /
• 1999

Effects of garlic juice (GJ), ethanol- (GJAE) and ethyl ether extract of garlic juice (GJEE), onion juice (OJ) and ethanol extract of onion juice (OJAE), garlic juice+Merit Blue (GJ+MB), ethanol extract of garlic juice+Merit Blue (GJAE+MB), onion juice+Merit Blue (OJ+MB), ethanol extract of onion juice+Merit Blue (OJAE+MB), and Merit Blue (MB) on budbreak, flowering, and maturity of plastic house-grown 'Daebong' grapes (Vitis labruscana B.) were studied. MB alone and in combination with other formulae hastened the budbreak, and double application was more effective than single one. Most of the buds sprouted in early forcing, but percent budbreak in late forcing was very poor except for MB application. In early forcing, single application of MB in combination with other formulae was most effective for hastening flowering while the response to double application was not consistent, and even delayed the flowering except for OJAE, MB, and OJ+MB. In late forcing, single application of all dormancy-breaking agents, especially MB in combination with other formulae, hastened the flowering while flowering response to double application was inconsistent, and even delayed the flowering except for OJAE+MB and OJ. Although there were no significant differences in harvest date among treatments and the number of application in early forcing, single and double application of MB alone and in combination with other formulae, especially double application of OJAE+MB hastened the harvest date for 12 days in late forcing culture.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.1
• /
• pp.7-13
• /
• 1989

The present study was carried out to get the basic information for clarifying physiological mechanism of breaking dormancy and sprouting in Panax ginseng roots. Changes in Abscisic acid (ABA) content and Gibberellin (GA) activity were investigated in one-year-old root during stratification at 4$^{\circ}C$. 15$^{\circ}C$. and 15$^{\circ}C$ after 60day-treatment at 4$^{\circ}C$. Sprouting rate at 15$^{\circ}C$ was 35％ in 30days storage at 4$^{\circ}C$ and 100％ in longer than 60days, but there was no sprout in both the constant treatment at 4$^{\circ}C$ or 15$^{\circ}C$ regardless of the treatment period. The longer the period of low temperature treatment. number of days to the first and 50％ sprouting was shortened, and number of days to 50％ from first sprouting was also shortened. ABA content in the upper part of root(contained bud) was gradually increased at both 4$^{\circ}C$ and 15$^{\circ}C$ as the treatment period was extended. and the degree of increase was higher at 15$^{\circ}C$. In the lower part. it showed a slight increase at 15$^{\circ}C$. while showed little change at 4$^{\circ}C$ throughout the treatment period. In the 15$^{\circ}C$ treatment after 60days at 4$^{\circ}C$, it was greatly increased in the upper part. while rather slightly decreased in the lower part of root. GA activity in the upper part was gradually decreased at both 4$^{\circ}C$ and 15$^{\circ}C$, and the degree of decrease was higher at 15$^{\circ}C$. In the lower part. it was similar tendency to those in the upper part. In the 15$^{\circ}C$ treatment after 60days at 4$^{\circ}C$. it was remarkably increased in both the upper and lower part. The increase was great in the low Rf region, while the decrease appeared relatively in the high Rf region compared to those of 60day-treatment at 4$^{\circ}C$. The above results indicated that the breaking dormancy and sprouting of bud were closely associated with the degree of GA activities in response to temperature condition .during stratification rather than the direct effect associated with the changes in ABA content.