• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.448-454
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• 2021

This study was conducted to the effect of low air temperature and light intensity conditions on yield and quality of tomato at the early stage of growth in Korea. Inplastic greenhouses, low temperature and low temperature with shade treatments were performed from 17 to 42 days after plant. Tomato growing degree days were decreased 5.5% due to cold treatment during the treatment period. Light intensity decreased 74.7% of growing degree days due to shade. After commencing treatments, the plant growth decreased by low temperature and low radiation except for height. Analysis of the yield showed that the first harvest date was the same, but the yield of the control was 3.3 times higher than low temperature with shade treatment. The cumulative yields at 87 days after transplanting were 1734, 1131, and 854 g per plant for control, low temperature, and low temperature with shade, respectively. The sugar and acidity of tomatoes did not differ between treatment and harvesting season. To investigate the photosynthetic characteristics according to the treatment, the carbon dioxide reaction curve was analyzed using the biochemical model of the photosynthetic rate. The results showed that the maximum photosynthetic rate, J (electric transportation rate), TPU (triose phosphate utilization), and R_d (dark respiration rate) did not show any difference with temperature, but were reduced by shading. Vcmax (maximum carboxylation rate) was decreased depending on the low temperature and the shade. Results indicated that low temperature and light intensity at the early growth stage can be inhibited the growth in the early stage but this phenomenon might be recovered afterward. The yield was reduced by low temperature and low intensity and there was no difference in quality.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.17-26
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• 1979

Comparative tolerance of the new rice varieties from Indicax Japonica cross to elastic and plastic chilling injuries was examined at the 3rd leaf-stage, the most sensitive stage to chilling during nursery, using a chilling chamber set 11\circ C, 13hrs. 20K lux day/5$^{\circ}C$ night. Seedlings were reared until 35 days after seeding in a 26\circ C, 13hrs. day / 18\circ C night chamber except the period of chilling treatment for 0, 3, 4, 6, 8 or 10 days. The new varieties were approximately twice susceptible to elastic injuries, and thrice susceptible to plastic injuries than the Japonica varieties in the term of chilling duration. Among the variables indicating apparant chilling injuries the reduction in dry matter responded most sensitively and differentiated well the varietal difference in chilling resistance even with shorter chilling period. Sequential aspects of the cause and effect relations involved in the development of the apparant chilling injuries are discussed and a schematic diagram is presented as Fig. 5 in the text.

• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.25-30
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• 1993

The buds of Hayward/Bruno tree were damaged from $-7^{\circ}C$ but serious damage was found on the buds treated at $-15^{\circ}C$ and $19^{\circ}C$. The bark tissue was more suceptible to low temperature than the bud. The trees were survived and bursted their at all on the top of the graft union and new shoots were formed from the rootstock of the tree. Yellowish area on the leaf surface was found, which is believed that as a result of low temperature. From these, the kiwifruit trees must be grafted with cold tolerant rootstocks will be clarified in future.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.79-84
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• 2001

The experiment were carried out to establish the optimal condition of bulblet size, low temperature treatment and time of incubation in acclimatization on stem emergence of Lilium oriental hybrids. The large size bulblet was better than middle and small size bulblets in percentage of stem emergence and weight of bulblets. The highest percentage of stem emergence was 95% in large size bulblet 'Acapulco' but small size bulblet of 'Casablanca' was no stem emergence. Low temperature treatment(5℃)for breaking dormancy was needed at least more than 9weeks. Weight of bulblets and percentage of stem emergence was not good in 5℃ treatment for 6 weeks. The best stem emergence showed 5 month growing in vitro and the weigh test bulblets during acclimatization of bulblet

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.35-39
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• 1994

Is obtain cell lines showing high level of rice cold tolerance, direct in vitro selection through cold stress on primary pollen callus derived from anther culture was carried out Genotypic difference in callus formation and plant regeneration was recognized Rates of albino was increased along the duration of cold stress. Reciprocal effects were not noticed in anther culturability There was no variants related to rice leaf discoloration in pollen derived lines from parental varieties, regardless of days of cold stress. The regeneration and recombination of rice leaf discoloration in 146 pollen-derived lines, 70 pollen-derived lines from cold stress at $0^{\circ}C$ for 10 days, and 830 F$_2$ plants presented normal distribution curves with skewness in tolerance and no significant difference among 3 populations. Direct in vitro selection for rice cold tolerance through cold stress on primary pollen callus derived from anther culture, therefore, was revealed ineffective as a in vitro technology.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.203-210
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• 1976

To abtain basic information in process developing cold tolerance rice variety, used 8 varieties which are the close crossing and the remote crossing in order to clarify how is being the differences of low temperature injury in same variety and the varietal difference at each growth stage under the low temperature treatment, 18$^{\circ}C$-12$^{\circ}C$ (day-night), and to establish the effective testing method for low temperature injury in rice plant. In this experiment, the varietal ifferences of low temperature injury were significant in rice plant, and found out that low temperature injury at the each growth stage from sowing to heading in same variety was not horizontal.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.277-280
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• 2002

Acid phosphatase in the radish young plant showed optimal activity at pH 5.5. The activity of acid phosphatase was maintained longer during the ABA (0.5 mM) treatment than those in control, whereas that was similar to the treatment of NaCl (0.5 mM). But during the cold (4$^{\circ}C$) treatment, the activity of acid phosphatase was decreased dramatically compared to the control, which was maintained almost on a constant level and increased gradually during 6 days. It showed that acid phosphatase was in relation to the change of biochemical reaction, which plants were coped with cold, NaCl and ABA stress.

• Journal of Bio-Environment Control
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• v.7 no.2
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• pp.109-115
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• 1998

This study was conducted to evaluate the growth and flowering responses of Eustoma grandiflorum cv. Azmasul, Azmahoon and Azmazo influenced by duration of storage at 1$0^{\circ}C$ of seedlings raised in warm season. The plants after cold treatment were cultivated in a glasshouse under natural day length with the minimum temperature of 12$^{\circ}C$. The stem thickness and number of leaves of Azmasul and Azmahoon were not affected by duration of cold treatment However, plant height, internode length fresh and. dry weights were significantly increased in the four-week treatment. In addition, four-week treatment increased flower weight and width. Bays to flowering of Azmasul and Azmahoon in four-week treatment were shortened by 20 days compared to the control or two-week treatment. Shoot growth and flower Qualify of Azmazo under the four-week treatment were promoted. Four-week treatment reduced the days to flowering of Azmazo by 31 and 36 days compared to the control and two-week treatment. The results of this study show that optimum duration for storage at l$0^{\circ}C$ for seedlings of Ewtoma grandiflorum cv Azmasul. Azmahoon and Azmazo grown in warm season is four weeks.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.2
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• pp.3-9
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• 1964

Root tips of wheat, soybean, cotton and barley were treated with cold temperature (12 or 24 hrs in $0^{\circ}C$ or 2$^{\circ}C$), 8-Hyd.exyquinolin (2 or 10 hrs in 0.03 or 0.1%) and colcllicine (2 or 10 hrs in 0.2 or 1, 0%), and the frequency of metaphase were observed. The results were summarized as follow; 1. Chilling the seminal roots before or after sooting from the seed significantly increased tile number of mitotic cells and the rate of metaphase cells to mitotic cells. The optimal duration of chilling seemed to be differ depending on the kinds of plant and 24 hours to be too long except wheat so far examined here. 9. 8-Hydroxyquinolin treatment, about 2 hours in 0.03%, increased the rate of metaphase cells. The higher concentration and the longer treatment of this chemical caused the lower frequency of mitotic cells generally. 3. Colchicine treatment, 2 to 10 hrs in 0.2 to 1.0%, increased the frequency of mitotic cells and the rate of metaphase cells. Colchicine treatment was same or superior than any other treatments on the increase of metaphase cells. 4. All the treatments examined here caused chromosome contraction with most serious in colchicine following by 8-Hydroxyquinolin and chilling. 5. The feasibility of general application of chilling under the check of proper temperature and proper duration depending on the kinds of crops were discussed.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.303-308
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• 2007

An accumulation levels of osmolytes in chilling-tolerant and chilling-sensitive cultivar of Cucurbits against chilling stress were determined during chilling stress. Total soluble sugar contents in tolerant cultivar did not changes fur 10 days after chilling stress, but then slightly increased 20 days after chilling stress. In sensitive cultivar, it was increased rapidly in the beginning of chilling stress, and increased 3.4 times as much 20 days after chilling stress as compared with unstressed plants. Proline contents in tolerant cultivar was rapidly increased by the beginning of chilling stress, and then increased 26.6 times 20 days after chilling stress as compared with unstressed plants. In sensitive cultivar, it was increased 22.0 times 20 days after chilling stress as compared with unstressed plants. A levels of glycine betaine (GB) in tolerant cultivar increased 1.9 times as much during the 20 days of chilling stress. However, concentration of GB in sensitive cultivar did not change during the chilling stress. When plants were treated exogenous GB as a foliar spray, chilling tolerance was significantly enhanced in both cultivars. The foliar application of exogenous GB was induced chilling tolerance by accumulation of GB in the plant organs. However, it does not accumulate endogenous proline.