• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.69-76
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• 1995

Cold acclimation involves changes in gene expression. BN28 and BN115 are two genes which are regulated by cold temperature and assumed having roles in cold acclimation. The objectives of this experiment was to explore the expression of BN28 and BN115 under field conditions. Six winter cultivars were planted at three different dates during the fall. The expression of the genes was determined by northern blot analysis of total RNA taken from leaves 15 to 30 day-intervals after planting. The expression of the two genes was detected within 15 days after planting well before onset of freezing tolerance in plants. This suggestes either their expression was a prerequisite of the freezing tolerance or their expression was regulated by other environmental factors as well as temperature. Two genes showed a different expression pattern suggesting they had a different regulatory system. Although timecourse increase in expression of the cold-regulated genes was matched with increase in freezing tolerance, the difference of expression in cultivar level at specific times of measurement was not correlated with freezing tolerance at the moment.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1507-1514
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• 2017

Objective: The Bashang Long-tail chicken (BS), an indigenous Chinese breed, is considered cold tolerant. We selected BS, the Rhode Island Red (RIR), and their reciprocal crossbreds for the present study. The objectives were: i) to validate whether BS is cold tolerant and whether egg production and cold tolerance of crossbreds could be improved; and ii) to determine the physiological characteristics that underlie cold tolerance and favorable egg production performance in cold environments. Methods: A total of 916 chickens were reared in warm and natural cold environments (daily mean ambient temperature varied from $7.4^{\circ}C$ to $26.5^{\circ}C$ in the warm environment and from $-17.5^{\circ}C$ to $27.0^{\circ}C$ in the cold environment). To investigate their adaptability to the cold environment, the egg production performance and body weight were monitored and compared between breeds and environments. The cloacal temperature and serum biochemical parameters were monitored to reveal the physiological characteristics underlie cold tolerance and favorable egg production performance in the cold environment. Results: The warm environment experiment showed that RIR had the highest egg production performance, and that the reciprocal crossbreds had a higher egg production performance than BS. While in the cold environment RIR had the lowest egg production performance, and the reciprocal crossbreds had a higher egg production performance than BS. In the cold environment BS and reciprocal crossbreds had higher triiodothyronine, tetraiodothyronine levels than RIR. At 35 and 39 wk of age, when the ambient temperature was extremely low (varied from $-20^{\circ}C$ to $0^{\circ}C$), serum glucose, follicle-stimulating hormone, luteinizing hormone, estradiol of BS and crossbreds were higher than RIR. Conclusion: Bashang Long-tail chicken has a favorable cold tolerance ability. Crossbreeding with RIR and BS is an effective way to develop cold tolerant chickens with improved egg production performance.

• 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.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.309-316
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• 2015

In this experiment, five commercial cultivars and one wild species of loquat were used to investigate frost tolerance and enzymatic activities in leaves and young fruits under cold stress at $-3^{\circ}C$. The frost injury, malondialdehyde (MDA) content, and oxygen-scavenging enzyme activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were studied. This results showed that the wild species 'Wild Oak-leaf' loquat was the most frost tolerant among accessions tested, followed by the cultivar 'Golden Block'. Other cultivars, 'Wu Gong Bai', 'Taicheng 4', 'Xiangzhong 11' and 'Zaozhong 6', were relatively weak in frost tolerance. The enzymatic activities of SOD, POD and CAT increased initially and then decreased as the exposure time increased. However, the enzymatic peak occurred later in the frost-tolerant accession than in the frost-sensitive accession. The correlation coefficients of MDA contents between leaves and immature fruits were from 0.93 to 0.99 in the five commercial loquat cultivars. For the 'Wild Oak-leaf' loquat, the correlation coefficients of MDA and POD were 0.98 and 0.95, respectively, but the coefficients for SOD, CAT and APX were relatively low. In general, there were good correlations between loquat leaves and immature fruits in MDA content and enzyme activities. These results indicate that analysis of these physiological and biochemical activities in loquat leaves could potentially be used to predict the cold tolerance in loquat at immature fruit stage and to accelerate breeding programs for cold tolerance in loquat.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.71-76
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• 2002

The one year old persimmon twigs were collected to know cold tolerance at different temperatures. The selected persimmon cultivar were mast commonly growing in southern part of Korea, such as Bong-Ok, Chungdo-Bansi, Naju-Pasi and Kiwonbang growing at attached farm of Kyungpook Nat. Univ. Browning of bud was the most significant at $-15^{\circ}C$. Naju-Pasi showed no difference in damage between $-5^{\circ}C$ and $-15^{\circ}C$ so called, it is cold tolerant cultivar. Browning of the woody part showed the same tendency with the bud at $-15^{\circ}C$. Chungdo-Bansi was shown the mast weak in cold tolerance than the other cultivars. Electric conductivity was higher at $-15^{\circ}C$ in all persimmon cultivars. Naju-Pasi and Bong-Ok cultivars were weak in cold tolerance even at $-10^{\circ}C$. Bud bursting was occurred at $-15^{\circ}C$ but few on another twigs tested. Naju-Pasi was the lowest while Kiwonbang was higher in the bud bursting. From these result, Naju-Pasi and Bong-ok cultivars were lower in cold tolerance. Kiwonbang cultivar was shown cold tolerance than the other cultivars. These results can be utilized for the persimmon cultivation at different localities in future.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.3
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• pp.163-168
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• 2001

"Hwasan 103" is a new cold-tolerant Italian ryegrass(Lo1ium multiflorum L.) variety developed by theNational Livestock Research Institute(NLR1) in 1999. To develop a cold-tolerant variety of Italianryegrass(Lo1ium multiflorum L.), cold-tolerant clones survived under - 13 - - 14$^{\circ}$C of minimum average airtemperature(MAAT) in January were selected at Hwachun, Kwangwon Province in 1995. Five clones ofselected clones were polycrossed for seed production by NLRI, RDA in 1996."Hwasan 103" was diploid variety, green in leaf color and broad in flag leaf width. Also it hassemi-prostrate and medium growth habit in late autumn and in early spring, respectively. "Hwasan 103" wasexcellent in lodging tolerance at harvesting time. First heading date of "Hwasan 103" was 14th May, it wassimilar to that of Marshall. Expecially, "Hwasan 103" survived about 50-70% under - 10- - 12'C ofMAAT in January, so it could be cold-tolerant variety that can be safely cultivated in regions higher than -9$^{\circ}$C of MAAT in January. Compared with Marshall "Hwasan 103" showed 3% higher fresh yield (57.8MTper ha) and it showed 2% higher dry matter yield (11.OMT per ha). Higher IVDMD and TDN and lowerADF and NDF were observed in "Hwasan 103" than those of Florida 80 and Marshall in Forage quality.(Key words : Italian ryegrass, Cold tolerance, New variety "Hwasan 103")all in Forage quality.(Key words : Italian ryegrass, Cold tolerance, New variety "Hwasan 103")n 103&")ot;)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.412-419
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• 1988

Cold-induced sterility is a problem of rice (Oryza sativa L.) production in temperate regions and high elevation tropics. The present study was conducted to measure combining ability, determine character associations. and to evaluate effectiveness of F$_2$selection for tolerance to this type of cold injury. The F$_1$, F$_2$, F$_3$ and reciprocal backcross F$_1$ populations of a nine-parent diallel were grown at Davis, California. a relatively cool location for rice. Additive genetic variance was predominant but some non -additive genetic variance existed for cold tolerance. Good general combining ability (GCA) was generally associated with the cold tolerant parents, 'M-201', and 'L-201', and poor GCA with the most susceptible parent. 7703008. Sterility was positively correlated with late heading. negatively with mature plant height. and negatively with spikelet number. Of the three agronomic characters, heading date had the greatest influence on sterility. Selection of F$_2$'s in seven crosses involving M-101, the most cold-tolerant parent, was effective for increasing cold tolerance. Realized heritability estimates for cold tolerance averaged 0.53, and observed selection response for cold-induced sterility averaged -9.4 percentage points.

• Journal of Oral Medicine and Pain
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• v.20 no.1
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• pp.97-103
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• 1995

The purpose of this study was to evaluate the effect of experimenter gender on pain report as well as the sex differences in pain threshold and pain tolerance. Cold pressor test and pressure pain threshold (PPT) test were performed on forty dental students by both of a male and a female experimenter separately with 1 day interval. The obtained results were as follows : There were no differences in pain threshold and pain tolerance between males and females when they were examined by the same gender experimenter in the cold pressor test, but when they were examined by the opposite gender experimenter the pain threshold of males was significantly higher than females. When the pain threshold was measured by the same gender experimenter, using a algometer, there was no differences in PPT between males and females. However, when the same measurements were done by the opposite gender experimenter, the PPT of males was significantly higher than females at anterior temporalis and inferior masseter. For cold pressor test, females tended to report lower levels of pain threshold and pain tolerance to a male experimenter than a female, but the differences were not significant. Although both pain threshold and pain tolerance were increased when males were examined by a female experimenter in the cold pressor test, the statistical significance was found only in pain tolerance. When subjects were examined by the opposite gender experimenter in the PPT text, females reported significantly higher levels of pain at inferior masseter and males reported significantly lower levels of pain at anterior temporalis and inferior masseter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.473-480
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• 1995

This study was conducted to know how cold tolerance of rice varieties is inherited. Several crosses were made between cold tolerant varieties and susceptible varieties, and their progenies were morphologically and physiologically evaluated each characters at cold water and natural conditions. The segregation modes of leaf discoloration by cold treatment in F$_2$ generations are agreed to simple inheritance ratio of R3 : Sl in four crosses among total seven cross combinations. In F$_1$ and F$_2$ generations, tall one was dominance in culm and panicle length and less reduction in culm and panicle length by cold treatment was overdominance or partial dominance, while more number of panicles per plant was dominance and more increasing of panicle numbers by cold water irrigation was overdominance. Heritability and heterosis in most characters showed high values, and heterosis in remote crosses was especially larger under the cold water treatment condition compare with that under natural condition.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.170-173
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• 2001

The design for cold extrusion dies is very important because the die insert is subjected to very high radial and hoop stresses. The design of cold extrusion dies has many constrained conditions. In this paper, two assumptions were proposed. First assumption was selected by yielding strength dependent on the to hoop stress of each ring in dies. Second assumption is that the maximum inner pressure is determined when yielding occurs in one ring of dies. To obtain the maximum inner pressure the flexible tolerance method was applied. A comparison of design values between the proposed method and the conventional method has been discussed.