• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.93-96
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• 2010

Breaker stage tomato fruits that were stored at low temperatures show typical chilling symptoms such as uneven ripening and a high respiration. Experiments were performed to assess and compare these chilling injury symptoms of breaker stage tomato fruits, and to gather basic data that can be used to decide whether horticultural crops receive chilling injuries. Tomato fruits that had been sorted in the breaker stage were stored at $2^{\circ}C$ for 0, 3, 6, and 9 days, and then their respiration rates were measured at 3, 6, 9, 12, 24, 36, and 48 h after moving them to room temperature. This treatment was repeated twice on the same procedures, except the storage periods, which were changed to 0, 1, 2, 3, and 10 days. The respiration rate was increased in a 1 day storage treatment, and the increasing rate rose higher with extended storage periods. The $a^*$ value, which represents the surface color of tomato fruits, was measured 10 days after moving to them into room temperature. Those with an increased $a^*$ value rate got dull and showed uneven coloring after 2 days' storage treatment. These two factors, the respiration rate and $a^*$ value of the surface, showed a high correlation (r = 0.9716, p < 0.001). Therefore, the chilling injury of breaker stage tomato fruits can be diagnosed by measuring the respiration rate after moving them into room temperature, and the degree of chilling injury can also be assessed in terms of the respiration increase rate.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.377-384
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• 2006

This study was conducted to investigate the effects of chemical application and amout of soil moisture on low temperature stress of cucumber seedling under the greenhouse conditions. When chilling treatments ($2^{\circ}C$) were begun at 07:00AM, survival rates of seedlings of two conditions; -0.3 bar and -5.5 bar were 28.3% and 83.3% respectively. But when chilling treatments were begun at 6:00PM - even the soil moisture condition was -0.3 bar - the survival rate was above the 87%. When reducing the soil moisture from -0.3 bar to -9.0 bar, ABA content in leaf was inc.eased by 6.5fo1d. Spraying of abscisc acid (ABA) before or after the chilling significantly increased the survival rates of seedlings, decreased the amounts of leaking electrolytes and prevented the yield reductions. ABA application on the soil before the chilling appeared to be more effective than the application after the chilling with foliar spray. Spraying of ABA ($10^{-5}M$), urea (0.2%) or $KH_2PO_4$ was effective in counteracting the low temperature, which causes growth deterioration and yield reduction in cucumbers.

• Korean Journal of Poultry Science
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• v.41 no.3
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• pp.159-164
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• 2014

This study was conducted to investigate whether water chilling had effect on water retention, freshness or internal temperature of chicken carcasses during chilling or storage in two different chicken processing plants (designated as A and B). A total of 240 carcasses from chicken processing plants (n = 120 per chicken processing plant) was randomly sampled and evaluated the effect of water chilling on carcass characteristics (i.e., water retention, water loss or freshness during chilling or storage). Torrymeter value was used as an indicator of freshness in chicken carcasses. Water chilling did not affect carcass water retention between the processing plants. However, chicken carcasses processing in B plant exhibited significantly higher freshness (p<0.05) compared with those in A plant. This difference in freshness was mainly due to the longer transit time through the water chiller in A versus B plants. Water loss of carcasses during storage was not different between plants. It was found that carcass freshness can be affected by water chilling time as manifested in this study. Further study is warranted to see whether freshness or microbiological status of chicken carcasses may be affected depending on the chilling methods, i.e., air or water chilling.

• Korean Journal of Agricultural Science
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• v.41 no.2
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• pp.75-83
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• 2014

Recently, a quick drop of air temperature in plastic film houses by adverse weather conditions leads to the occurrence of low temperature damages to growing crops. Chilling injury, defined as a variety of growth restriction occurring below the optimal temperature, is one of environmental factors strongly affecting crop growth and yield. Low temperature causes the restricted evapotranspiration, reduced mineral uptake (P > K > $NO_3{^-}$), and an increase in electrolyte leakage such as K. Despite being different with plant species, an accumulation of soluble carbohydrates such as glucose, fructose, sucrose and starch under chilling condition is well known. A variety of environmental stresses are known to cause oxidative damage to plants either directly or indirectly by triggering an increased level of production of reactive oxygen species (ROS), and, to combat the oxidative damage, plants have the antioxidant defense systems comprising of enzymes, SOD, POD, CAT, GPX and APX, and non-enzymes, ascorbate, gluthathione, ${\alpha}$-tocopherol, phenolic compounds, carotenoid and flavonoids. The aim of this review is to provide basic information to build chilling-indicators and optimal nutrition management under adverse temperature conditions as broadly considering mineral uptake, carbohydrate metabolism and antioxidative defense system.

• Journal of Environmental Science International
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• v.20 no.4
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• pp.541-549
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• 2011

This experiment was held to identify the germination feature of Papaver radicatum var. pseudoradicatum which has high economical value. Seeds were collected in the Mt. Changbai in China. To eliminate dormancy of the seeds, chilling treatment were carried out in the $5^{\circ}C$ refrigerator. 30 days, 60 days, 90 days, 120 days of chilling treatments were taken. After being Treated, seeds were under 15, 20, $25^{\circ}C$ of temperature and light, dark conditions respectively to see the differences in germination. Within many features, germination ratio of seeds and germination period were investigated. Also, features related to early growth were checked through the closer look into acrospire, growth of cotyledon of young plant. Over 30 days of chilling treatment was all effective. Especially, 120 days of chilling treatment was most effective. The seeds germinated well in the light conditions. 120 days of chilling treatment, $15^{\circ}C$, light conditions were found to be most effective conditions as 54.5% of the seeds germinated. The germination period was 4.29 days. 30 days after germinating, length of the aerial part had been 1.90 cm. But after 45 days, the length grew rapidly to 4.58 cm. Fresh weight of scales plant was also increased dramatically after 45 days. Therefore, transporting the plant 45 days after seeding judged to be good.

• Korean Journal of Plant Resources
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• v.29 no.3
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• pp.339-346
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• 2016

This study was carried out to develop an effective seed propagation method for Thalictrum rochebrunianum var. grandisepalum (H. Lev.) Nakai by analyzing seed dormancy types and germination characteristics. Seeds were collected between September to October at Gangwon province, and well-selected seeds were used while being dry-stored at 4±1℃. The seed size ranged 4.52 × 1.58 ㎜ and the weight of thousand seeds were 1,603.5 ± 0.02 ㎎. The moisture content was 7.2%. Seeds were achene type, and morphology characters showed an elliptical shape and rough texture, and light brown in color. Moist-chilling treatment was conducted for dormancy breaking because the seeds had an undeveloped embryo of liner type. The embryo had developed during a moist-chilling period, constantly, and fully developed in 10 weeks. Consequently, it seemed to be non-deep complex or intermediate complex type of morphophysiological dormancy, and embryo dormancy was broken by wet-chilling for 10 weeks. After 10 weeks of wet-chilling treatment, seed germination began. Germination percentage was higher in dark condition raher than light condition and recorded the maximum at 25℃ in the dark (16.3%). A pre-soaking treatment with a combined plant growth hormones promoted germination and shortened T₅₀. Specifically, seed germination of 84.5% was achieved by pre-soaking of seeds with a combined solution of 500 ㎎/L GA₃ and 10 ㎎/L kinetin for 24 h after a wet-chilling treatment for 10 weeks. Thus the effect of plant growth hormones coupled with chilling temperature on seed breaking dormancy provide asubsequent growth of seedlings for successful plantation.

• Journal of Photoscience
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• v.12 no.1
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• pp.33-39
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• 2005

Plants possess the ability to dissipate the excitation energy for the protection of photosynthetic apparatus from absorbed excess light. Heat dissipation is regulated by xanthophyll cycle in thylakoid membranes of chloroplasts. We investigated the mechanistic aspects of xanthophyll cycle-dependent photoprotection against low-temperature photoinhibition in plants. Using barley and rice as chilling-resistant species and sensitive ones, respectively, chilling-induced chlorophyll fluorescence quenching, composition of xanthophyll cycle pigments and mRNA expression of the zeaxanthin epoxidase were examined. Chilled barley plants exhibited little changes in chlorophyll fluorescence quenching either of photochemical or non-photochemical nature and in the photosynthetic electron transport, indicating low reduction state of PS II primary electron acceptor. In contrast to the barley, chilled rice showed a marked decline in those parameters mentioned above, indicating the increased reduction state of PS II primary electron acceptor. In addition, barley plants were shown to have a higher capacity to elevate the pool size of xanthophyll cycle pigments in response to cold stress compared to rice plants. Such species-dependent regulation of xanthophyll cycle activity was correlated with the gene expression level of cold-induced zeaxanthin epoxidase. Chilled rice plants depressed the gene expression of zeaxanthin epoxidase, whereas barley increased its expression in response to cold stress. We suggest that chilling-induced alterations in the pool size of xanthophyll cycle pigments related to its capacity would play an important role in regulating plant's sensitivity to chilling stress.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.264.1-264
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• 1995

No Abstract, See Full Text

• Applied Biological Chemistry
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• v.15 no.3
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• pp.187-192
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• 1972

The qualitative and quantitative changes in RNA in terms of RNase activity of rice plants subjected to the chilling temperature were studied. The total RNA level increased at the early stage and thereafter decreased continuously while the progress of the chilling injury. The change of total RNA was mainly dependent upon the change of ribosomal RNA with soluble RNA less changed. Parallelism between total RNA level and RNase activity was observed at the early stage of chilling injury, while the inverse relationship of RNA RNase was seen in the later stage. Our observations indicate that synthetic function of RNase may be more closely related to ribosomal RNA than soluble RNA.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.26-30
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• 2008

This study was conducted to identify the effect of chilling temperature (-3 and $6^{\circ}C$) and aging (1- and 7-day) on objective meat quality, collagen solubility, and free amino acids in pork (longissimus muscle of Yorkshire). Warner-Bratzler (WB)-shear force indicated that variation in chilling temperature had no detectable effect on meat tenderness and tenderization during the 7-day aging period. Among the 13 detected free amino acids, only 3 amino acids (histidine, valine, leucine) were significantly affected by the temperature treatment (p<0.05). Collagen solubility was significantly increased at $6^{\circ}C$ treatment (p<0.05). There was a significant linear relationship (r=0.67, p<0.05) between changes in free amino acids and WB-shear force during the 7-day aging period. These results confirmed that chilling conditions had significantly affected collagen solubility, and meat tenderization occurred in direct proportion to an increase in free amino acids.