• Journal of Photoscience
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• 제3권1호
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• pp.9-14
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• 1996

For three cultivars of chilling-sensitive cucumber plants, chilling sensitivity was evaluated in terms of photosynthetic activity using Chl fluorescence techniques. Low-temperature treatment caused a decrease in photosynthetic activities of cucumber leaves, measured as CO$_2$ exchange, as well as the decrease in the stomatal conductance. FR of the three cultivars decreased after chilling for 24 h in light and the extent of decline of F$_R$ was the greatest in 'Chosaeng' cultivar. When these plants were recovered from light-chilling, 'Chosaeng' and 'Samchuk' cultivars did not fully restore the original value of F$_R$ after 24 h of recovery, in contrast to 'Ilmi' cultivar which showed a rather efficient recovery. The results of FR study showed that 'Chosaeng' was most susceptible, whereas Ilmi was most resistant, to chilling among the three cultivars of cucumber plants. When quenching coefficients for chlorophyll fluorescence was analyzed after chilling the cucumber plants for 24 h in light, 'Chosaeng' elicited more rapid declines in the coefficients for photochemical quenching (qQ), non-photochemical quenching (qNP) and energy-dependent quenching (qE) than 'Ilmi' and 'Samchuk'. The implications of these observations are discussed in relation to the growth habits of the respective cultivars in the field. The results showed that measurement of chlorophyll fluorescence was an effective means of screening chilling tolerance of cucumber plants. Furthermore, the study on the chlorophyll fluorescence induction and fluorescence quenching charactersitics showed that low temperature could accelerate inhibition of photosynthesis in chilling-sensitive plants, by limiting Calvin cycle activity and disrupting, in part, the energy dissipation mechanims of the photosystem II.

• 한국동물위생학회지
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• 제40권4호
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• pp.245-251
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• 2017

Cold air or ice water are used to chill poultry carcasses after slaughter. In order to compare the microbial reduction effect of two different chilling systems in poultry carcasses, Pre-and post-chilled carcass samples were tested for contamination agents such as aerobic bacteria counts, E. coli counts and Salmonella spp. counts. Water chilling system showed higher reduction ratio of bacteria than air chilling system during the three seasons. Also, aging of slaughter facility was related with bacterial contamination of pre-chilld carcasses. And additional volatile basic nitrogen (VBN) test were conducted in poultry packing meats and it increased steadily during 15 days. VBN at 8~9 days were over 13 mg% with putrid smell. Poultry packing meats by water chilling system were fresher than air chilling system during early storage time. But those decayed faster after 9 days.

• 현장농수산연구지
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• 제10권1호
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• pp.77-90
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• 2008

본 연구는 오이묘의 생육단계에 따라 저온처리 온도와 지속기간이 오이 생육, 과실특성 및 수량에 미치는 영향을 구명하고자 실시하였으며 주요 결과는 다음과 같다. 1. 10시간 저온처리(3℃ 및 0℃)하여 20일간 수경재배한 오이의 초장은 무처리 (20℃)에 비해 각각 25 및 30%, 엽면적은 34 및 37% 감소되었으나, 6℃ 처리에서는 무처리와 큰 차이가 없었다. 저온처리 기간에 따른 생육저해는 처리 시간에 비례하여 증가하는 경향이었다. 2. 저온처리(3℃, 10시간)횟수를 1, 2 및 3회로 증가할수록 초장, 엽면적 및 건물중은 무처리에 비해 크게 감소하였으나 1회와 2회 처리간에는 유의차가 없었고, 3회 연속처리에서만 현저히 감소하였다. 3. 오이과실의 개화 후 일수에 따른 신장속도는 무처리는 0.61~2.60cm/일 인데 비하여 0℃, 15시간의 저온 처리는 0.59~2.26cm/일로 약 10% 감소되었다. 4. 저온처리(0~3℃,10시간)는 오이의 상품과율을 25~26% 감소시켰고, 하품과율은 현저히 증가시켰다. 5. 오이 수량은 6℃, 10시간 처리에서는 무처리와 차이가 없었으나 3℃와 0℃처리는 무처리에 비해 20일묘에서 15~25%, 30일묘에서 22~37% 감수되었다. 0℃에서 5시간, 10시간 및 15시간 저온처리하였을 때에는, 무처리에 비해 각각 18%, 30%, 및 36% 감수되었다.

• 생물환경조절학회지
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• 제16권2호
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• pp.121-129
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• 2007

저온 또는 건조 처리에 따른 토마토 유묘의 생육과 부위별 항산화효소의 반응 양상을 분석한 결과, 토마토 유묘의 생체중은 처리 후 12일째에 대조구에 비해 각각 69.5% 와 50.6% 감소하였다. SOD와 POD의 활성은 대조구에 비해 저온 또는 건조 처리에서 높은 활성을 보였는데, 저온 처리시에는 뿌리에서 더 높은 활성을 보였고 건조 처리에서는 잎과 줄기에서 높은 활성을 보였다. 이러한 결과는 동위효소의 발현양상에서도 일치하였다. GR의 활성은 저온 또는 건조 처리시 대조구보다 높은 활성을 보였는데, 잎과 줄기에서는 저온과 건조 처리간의 차이는 없었지만, 뿌리에서는 건조 처리가 높은 경향을 보였다. GR 동위효소 발현양상은 저온과 건조처리시에는 GR-3 밴드가 잎에서는 발현되어 대조구와 차이가 있었지만, 줄기와 뿌리에서는 큰 차이가 없었다. PPO 활성은 잎에서는 모든 처리에서 차이가 없었지만, 줄기와 뿌리에서는 저온 또는 건조 처리에서 대조구보다 높은 경향을 보였다. 특히 줄기의 PPO 활성은 저온 처리보다 건조처리에서 높았고 뿌리의 PPO 활성은 건조 처리보다 저온 처리에서 높았다. 동위효소의 발현양상에서도 건조처리에서는 줄기에서, 저온 처리에서는 뿌리에서 높은 밀도를 보여 불량 환경에 따른 부위별 반응 차이를 잘 반영해 주었다.

• 한국작물학회지
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• 제24권2호
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• pp.17-26
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• 1979

Indica \times Japonica 교잡에 의해 육성된 수도신품종들의 유묘기 내냉한계와 내냉발현특성을 Janica품종들과 비교 고찰하고자 10개 품종을 유묘기 내냉성이 제일 약한 제 3 엽기에 주간 11\circ C야간 5\circ C의 저온조건에 0, 3, 4, 5, 8, 10일 처리한 결과는 다음과 같다. 1. 저온처리 전후에 주야 26\circ C / 18\circ C에서 생장한 파종 후 35일묘의 건물중이 무처리묘의 90% 이상이 되는 최장저온처리기간은 신품종들의 경우 0.8~2.8일 간으로써 특히 조생통일이 짧고 밀야 2003가 길었으며, Japonica 품종들의 경우 4.0~5.2일간으로써 신품종들보다 가역적 내냉한계기간이 배정도 길었다. 2. 저온처리에 따른 냉해발현 종료후 묘생존율이 90%이상되는 최장저온처리기간은 신품종들의 경우 3.0~5.6 일간으로써 수원 258호가 제일 짧고 수원 25001가 제일 길었으며, Japonica 품종들은 공시품종 모두 10일간 이상으로 신품종들보다 비가역적 내냉한계기간이 2~3배 이상 길었다. 3. 저온처리중 엽신변색고사율(y_1) 및 묘고사율(y_2), 저온처리 후 발현된 모신변색고사율(y_3), 묘고사율(y_4), 냉해를 받은 35일묘의 초장(y$_{5}$)과 건물중(y$_{6}$)은 모두 저온처리기간(x)과 고도로 유의한 상관성을 보였는데 특히 y_1, y_3, y$_{6}$와 높은 상관성을 보였으며, y_1~y$_{6}$들 상호간에도 모두 고도로 유의한 상관성을 보였으나 특히 y_1과 y_3, y_3와 y$_{6}$의 상관성이 컸다. 4. 냉해징상들의 발현순서와 상태들간의 상관성 분석결과로부터 가역적 및 비가역적, 직접적 및 간접적 냉해의 발생과 그들의 복합현상으로써 결과되는 관찰되는 냉해징상의 발현과정 모식도를 작성하여 그림 5에 제시하였다. 5. 수도유묘의 내냉성 평가에 있어서 가역적 피해와 비가역적 피해를 종합적으로, 그리고 정량적으로 나타내며 일반적으로 냉해를 나타내는 조사형질들 중 냉해에 가장 예민한 반응을 보이는 건물중율을 1차요인으로 취급할 것으로 제의한다.

• Journal of Photoscience
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• 제7권2호
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• pp.39-44
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• 2000

To examine the chilling tolerance lipids, we compared the chilling susceptibility of photosystem II of wild type tobacco plants with that of transgenic tobacco plants, in which the sensitivity to chilling had been enhanced by genetic modification of fatty acid unsaturation of chloroplast membrane lipids. The transgenic tobacco plants were found to contain reduced levels of unsaturated membrane fatty acids by being tansformed with cDNA for glycerol-3-phosphate acyltransferase from squash. For the purpose of studying on the functional integrity of photosystem II during low-temperature photoinhibition, the photochemical efficiency was measured as the ration of the maximun fluorescence of chlorophyll (Fv/Fm) of photosystem II. In parallel with an investigation on the transgenic plants, susceptibility of chilling-resistant species, such as spinah and pea, and of chilling-sensitive ones, such as squash and sweet potato, to low-temperature photoinhibition was also compared in terms of room temperature-induced chlorophyll fluorescence from photosystem II. When leaf disks from the two genotypes of tobacco plants were exposed to light at 5$^{\circ}C$, the transgenic plants showed more rapid decline in photochemical activity of photosysytme II than wild-type plants. When they were pretreated with lincomycin, an inhibitor of chloroplast-encoded protein synthesis, the extent of photoinhibition was even more accelerated. More impottantly, they showed a comparable extent of photoinhibition in the presence of lincomycin, making a clear contrast to the discrepancy observed in the discrepancy observed in the absence of lincomycin. Restoration of Fv/Fm during recovery from low-temperature photoinhibition occurred more slowly in the transgenic tobacco plants than the wild-type. These findings are discussed in relation to fatty acid unsaturation of membrane phosphatidylglycerol. It appears that the ability of plants to rapidly regenerate the active photosystem II complex from might explain, in part, why chilling-resistant plants can toleratlow-temperature photoinhibition.

• Asian-Australasian Journal of Animal Sciences
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• 제20권12호
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• pp.1895-1900
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• 2007

An experiment was carried out to investigate the effects of different chilling temperature on duck breast and leg meat quality. Duck carcasses were chilled for 30 minutes in water at either $0^{\circ}C$, $10^{\circ}C$ or $20^{\circ}C$ within 20 minutes of post mortem with 6 carcasses per group. Results showed no significant effects of chilling temperature on ultimate pH, protein solubility, sarcomere length and shear force value for duck breast or leg meat (p>0.05). Leg meat had higher ultimate pH, redness and shear force value, lower cooking loss, lightness, yellowness and protein solubility values than breast meat. The interaction of meat type and chilling temperature on cooking loss was significant (p<0.05). The effect of chilling temperature on cooking loss was more severe in leg meat than breast meat and $20^{\circ}C$ chilling resulted in significantly higher cooking losses than the other chilling temperatures. Results of this experiment revealed that duck carcass can be chilled at $10^{\circ}C$ without any harmful effect on meat quality including toughness of meat.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2002년도 정기총회 및 제9회 광과학 학술심포지움 논문초록
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• pp.58-58
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• 2002

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2002년도 봄 학술발표대회 발표논문집
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• pp.468-471
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• 2002

The present study was undertaken to Investigate the effects of low temperature and salicylic acid (SA) on chilling tolerance In acclimated and nonacclimated cucumber seedlings. Acclimation significantly affected survival and shoot dry weights. Injuries of acclimated seedlings at the third leaf stage were on the average smaller by half than those of the nonacclimated ones. Chilling caused a large increase in free proline levels, regardless of acclimation status. Exogenous treatment with SA resulted in improvement in growth and survival of acclimated, chilled seedlings, indicating SA and acclimation have common effects. Cycloheximide treatment In the presence of SA restored acclimation-induced chilling tolerance. An elevated proline level was observed in cold-treated and SA- treated plants and the level was more pronounced in the light than in the dark at chilled temperature, indicating that endogenous proline may play a role in chilling tolerance.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 Proceedings of the 17th Symposium on Plant Biology Environmental Stress and Photosynthesis
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• pp.68-82
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• 1999

CHilling tolereance of plants are closely correlated with the degree of fatty acid unsaturation of membrane lipids. We studied the effects of low-temperature photoinhibition on the photochemical efficiency of photosystem II in terms of fatty acid unsaturation of thylakoid membranes lipids isolated from chilling -sensitive plants and chilling -resistant ones. To directly test the chilling tolerance of photosynthetic machinery in relation to membrane lipids, we further compared wild type tobacco plants with that of transgenic tobacco plants, in which the sensitivity to chilling had been enhanced by genetic modification of fatty acid unsaturation of chloroplast membrane lipids. The transgenic tobacco plants were found to contain reduced levels of unsaturated membrane fatty acids after being transformed with cDNA for glycerol-3-phophate acyltransferase from squash. The functional integrity of photosystem II during and recovery of photosynthesis from low-temperature photoinhibition will be discussed in connection with the degree of fatty acid unsaturation of chlorophast membranes lipids.