• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.13-13
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• 2022

Recently, stable crop production is threatened by the effects of climate change. In particular, it is difficult to consistently maintain agricultural policies due to large price fluctuations depending on the difference in total domestic rice production from year to year. For stable rice production amid changes in the crop growing environment, development of varieties with improved disease resistance and abiotic stress stability is becoming more important. In here, drought and cold tolerant trait have been studied. First, for the development of drought tolerant varieties, we analyzed which agricultural traits are mainly affected by domestic drought conditions. As a result, it was observed that drought caused by the lack of water during transplanting season inhibits the development of the number of tiller and reduces the yield. 'Samgang' was selected as a useful genetic resource with strong drought tolerant and stable tiller number development even under drought conditions by phenotype screening. Three of drought tolerant QTLs were identified using doubled haploid (DH) population derived from a cross between Nacdong and Samgang, a drought sensitive and a tolerant, respectively. Among these QTLs, when qVDT2 and qVDTl1 were integrated, it was investigated that the tiller number development was relatively stable in the rainfed paddy field conditions. It is known that the high-yielding Tongil-type cultivars are severely affected by cold stress throughout the entire growth stage. In this study, we established conditions that can test the cold tolerance phenotype with alternate temperature to treat low temperatures in indoor growth conditions similar to those in field conditions at seedling stage. Three cold tolerant QTLs were explored using population derived from a cross between Hanareum2 (cold sensitive variety, Tongil-type) and Unkwang (cold tolerant variety, Japonica). Among these QTLs, qSCT12 showed strong cold tolerant phenotype, and when all of three QTLs were integrated, it was investigated that cold tolerant score was relatively similar to its donor parent, Unkwang, in our experimental conditions. We are performing that development of new variety with improved cold tolerant through the introduction of these QTLs.

• BMB Reports
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• v.36 no.5
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• pp.427-432
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• 2003

Jute is the principal coarse fiber for commercial production and use in Bangladesh. Therefore, the development of a high-yielding and environmental-stress tolerant jute variety would be beneficial for the agro economy of Bangladesh. Two molecular fingerprinting techniques, random-amplified polymorphic DNA (RAPD) and amplified-fragment length polymorphism (AFLP) were applied on six jute samples. Two of them were cold-sensitive varieties and the remaining four were cold-tolerant accessions. RAPD and AFLP fingerprints were employed to generate polymorphism between the cold-sensitive varieties and cold-tolerant accessions because of their simplicity, and also because there is no available sequence information on jute. RAPD data were obtained by using 30 arbitrary oligonucleotide primers. Five primers were found to give polymorphism between the varieties that were tested. AFLP fingerprints were generated using 25 combinations of selective-amplification primers. Eight primer combinations gave the best results with 93 polymorphic fragments, and they were able to discriminate the two cold-sensitive and four cold-tolerant jute populations. A cluster analysis, based on the RAPD and AFLP fingerprint data, showed the population-specific grouping of individuals. This information could be useful later in marker-aided selection between the cold-sensitive varieties and cold-tolerant jute accessions.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.363-369
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• 1999

Reconstruction of the past vegetational changes of Korea in connection with climate changes enables to understand the impacts of past and future global warming on alpine vegetation. Despite the early appearance of the cold-tolerant vegetation since the Mesozoic Era. the occurrence of warmth-tolerant vegetation during the Oligocene and Miocene implies that most of alpine and subalpine vegetations have been confined to the alpine and subalpine belts of northern Korean Peninsula. The presence of cold-episodes during the Pleistocene. however. might have caused a general southward and downslope expansions of cold-tolerant alpine and subalpine vegetation. But the climatic warming trend during the Holocene or post-glacial period eventually has isolated cold-tolerant alpine and subalpine vegetation mainly in the northern Korea. but also on scattered high mountains in the southern Korea. The presence of numerous arctic-alpine and alpine plants on the alpine and subalpine belts is mainly due to their relative degree of sensitivity to high summer temperatures. Global warming would cause important changes in species composition and altitudinal distributional pattern. The altitudinal migration of temperate vegetation upward caused by climatic warming would eventually devastate alpine plants.

• Journal of Forest and Environmental Science
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• v.35 no.4
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• pp.232-239
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• 2019

This study was carried out to establish an efficient selection condition for cold-tolerant individuals among evergreen Quercus spp. To select higher cold-tolerant individuals among four species of evergreen Quercus spp. (Q. acuta, Q. glauca, Q. myrsinaefoila, and Q. salicina), an-year-old seedlings of each species were exposed to low temperature in serial, and then examined for the death of cell tissue and the surface temperature was monitored. It was shown that the higher numbers of seedlings of Q. myrsinaefolia were survived than the others when those seedlings are exposed to cold stress. Thus, selection of the cold tolerant individuals was conducted on Q. myrsinaefolia seedlings. The limit low temperature condition for selecting cold-tolerant individuals was -6℃ for 24 hrs because no seedling of Q. myrsinaefolia was survived after exposed to -7℃ for 24 hours. It was shown that the leaf surface temperature of the selected individuals was higher than those of the non-selected individuals when they were exposed to cold-stress while monitoring them using thermal graphic camera. The results in this study can be used for expanding afforestation area of tree species of the warm temperate zone for preparation of climate change.

• Korean Journal of Breeding Science
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• v.43 no.1
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• pp.1-13
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• 2011

Low temperature stress is one of the major negative factors affecting vegetative and reproductive growth of rice. To better understand responses of rice plants to low temperature we analyzed transcriptome expression patterns in glumous flower of cold-tolerant japonica rice variety, Stejaree45, and cold-susceptible variety, HR19621-AC6 at booting stage under cold water irrigation. A total of 2,411 probes were differentially expressed by low temperature in glumous flowers of the two varieties. Some important genes involved in hormone biosynthesis showed variety-specific regulation. Expression of GA20ox3 and GA2ox, among the genes involved in GA biosynthesis, was regulated differentially in the two varieties. Among the genes involved in IAA biosynthesis, YUCCA1 and TAA1:1 showed variety-specific regulation. Among the genes involved in cytokinin biosynthsis and signaling, expression of LOG, HK1 and HK3 was significantly down-regulated only in the cold-susceptible variety. Among the genes involved in ABA biosynthesis, NSY and AAO3 were down-regulated only in the cold-tolerant variety. In general, genes involved in GA, IAA and cytokinin biosynthesis responded to cold temperature in such a way that capacity of those bioactive hormones is maintained at relatively higher levels under cold temperature in the cold-tolerant variety, which can help minimize cold stress imposed to developing reproductive organs in the cold-tolerant variety.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.289-294
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• 2004

This study was carried out to investigate the antioxidative enzymes and isozymes between chilling-tolerant and -susceptible varieties at the booting stage under cold water stress $(13^{\circ}C)$ in japonica rice. Total SOD, CAT, POX, and GR activities on the basis of protein were found to be important factors to defend cold water stress. Especially, SOD and CAT activities showed distinctive differences between chilling-tolerant and -susceptible varieties. Chilling-tolerant varieties were higher than chilling-susceptible varieties for SOD and CAT activities. One of eight isozyme bands for SOD was a inducible isoform. Three isozymes for CAT and one isozyme for POX were closely correlated with defense to cold water stress. Total GR activities except Stejaree 45 on the basis fresh weight and POX were increased by cold water stress, but there was no difference between chilling-tolerant and -sus­ceptible varieties.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.3
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• pp.157-162
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• 2001

"Hwasan 102" is a new cold-tolerant Italian ryegrass(Lo1ium rnultiflorum L.) variety developed by theNational Livestock Research Institute(NLRI) in 1999. Having cold tolerance in Italian ryegrass is an importantfor enlargement of cultivation area and increase of productivity in Korea. To develop the cold-tolerant varietyof Italian ryegrass, cold-tolerant clones survived under - 13- - 14$^{\circ}$C of minimum average air temperature(MAAT) in January were selected at Dun Nae, Kwangwon Province in 1993. Five of selected clones werepolycrossed for seed production by NLRI, RDA, in 1995."Hwasan 102" was tetraploid variety, dark 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 102" withlow plant height at harvesting time was excellent in lodging tolerance. First heading date of "Hwasan 102"was 19th May, it was similar to that of Marshall. Expecially, "Hwasan 102" survived about 60% under - 10- - 12$^{\circ}$C of MAAT in January, so it could be cold-tolerant variety that can be safely cultivated in regionshigher than -9'C of MAAT in January. Compared with Marshall, "Hwasan 102" showed 8% higher freshyield (59.2MT per ha) but it showed 2% lower dry matter yield (9.6MT per ha). Higher IVDMD and TDNand lower ADF and NDF were observed in "Hwasan 102" than those of Florida 80 and Marshall in Foragequality.(Key words : Italian ryegrass, Cold tolerance, New variety "Hwasan 102")rshall in Foragequality.(Key words : Italian ryegrass, Cold tolerance, New variety "Hwasan 102")san 102&")ot;)

• 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;)

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.1-6
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• 2000

Improvement of cold-tolerance of Italian ryegrass(Lo1ium multiflorum L.) is an important breeding objectivefor enlargement of cultivation area in Korea. To develop the cold-tolerant variety of Italian ryegrass,cold-tolerant clones survived under - 13- - 14$^{\circ}$C of minimum average air temperature in January wereselected in the area of Dun Nae, Kwangwon Province. The 5 lines of Italian ryegrass clones selected werepolycrossed for seed production. Synthetic seeds were examined on growth characters and forage productionsin Suwon from 1996 to 1998, in Unbong 1997 and in Younchun 1998, respectively. The growth charactersand forage productions of Italian ryegrass variety named as "Hwasan 101" were summarized as follow ;ltalian ryegrass variety, Hwasan 101 was tetraploid and showed semi-prostrate growth habit in autumn andwas not only dark green in leaf color and broad in flag leaf width but also excellent in leafiness. Also, itshowed low plant height at first heading date of 20th May and excellent lodging tolerance. Expecially,Hwasan 101 in all trial regions was 80 -90% of winter survivals that was higher than 60 -90% of Florida80 and Marshall varieties. Therefore we estimate that Hwasan 101 can be cultivated in regions that is higherthan -9$^{\circ}$C in minimum average air temperature and lower than 400m in sea level. In forage production ofHwasan 101, fresh weight and total digestible nutrient(TDN) yield were 66,940 and 6,551kghq and drymatter yield was 10,050kgha. In conclusion, Italian ryegrass, Hwasan 101 was medium and late maturingvariety but excellent in cold-tolerance, lodging-tolerance, leafiness, and forage production.(Key words : Italian ryegrass, Cold tolerance, New variety)ian ryegrass, Cold tolerance, New variety)

• Journal of the Korean Geographical Society
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• v.36 no.3
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• pp.247-257
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• 2001

The relationships between the distribution of 132 species, 61 genera evergreen broad-leaved trees and shrubs(EBTS) and climatic factors have discussed. The distributional patterns of EBTS were categorized into seven groups on the basis of the number of distributing sites, distributional attitudes and latitudes. Out of seven group. the cold-tolerant EBTS were common at groups I and II, along tilth Empetrum nigrum var. japonicum. Diapensia lapponics subsp. obovata of group III. However, the warmth-tolerant EBTS were rich at groups III. IV V, and VI The lower distributional limits of cold-tolerant EBTS in the groups I and UU decreased as one moves toward south. The upper distributional limit of warmth-tolerant EBTS in the groups III, IV and V decreased with increasing latitude. However. no clear distributional tendency is noticed in the groups VI and VII. The range of warmth-tolerant EBTS appear to show close relationship with the January mean temperature -4 $\^{C}$ and January mean minimum temperature -9$\^{C}$ than others. On the other hand, that of the cold-tolerant EBTS seem to respond well to the August mean temperature 19$\^{C}$ and August mean maximum temperature 26$\^{C}$ than others.