• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.172-178
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• 1998

Freezing-resistant plants can survive subzero temperatures by withstanding extracellular ice formation. During cold acclimation, their leaves accumulate antifreeze proteins (AFPs) that are secreted into the apoplast and have the ability to modify the normal growth of ice crystals. Three barley, two wheat and two rye cultivars were grown under two different temperature regimes (20/16$^{\circ}C$ and 5/2$^{\circ}C$, day/night). Apoplastic proteins from winter cereals were separated by SDS-PAGE and detected with antisera to AFPs from winter rye. Apoplastic proteins accumulated to much higher levels in cold-acclimated (CA) leaves compared with nonacclimated (NA) ones in winter cereals. After cold acclimation, the protein concentration of apoplastic extracts increased significantly from 0.088 $mgmL^{-1}$ to 0.448 $mgmL^{-1}$, with about 5-fold increment. Also, the apoplastic protein content per gram leaf fresh weight in CA leaves ranged from 31 $\mu\textrm{g}$ $(gFW)^{-1}$ to 120 $\mu\textrm{g}$ $(gFW)^{-1}$ with an averaged value of 77 $\mu\textrm{g}$ $(gFW)^{-1}$, and coefficients of variation of 54.9%. The CA leaves in Musketeer (a Canadian winter rye cultivar) showed the greatest AFPs and antifreeze activity followed by 'Geurumil' (a Korean winter wheat cultivar), and 'Dongbori l' (Korean facultative barley cultivar). The proteins secreted into the wheat leaf apoplast at CA condition were more numerous than those observed in winter rye, where two $\beta$-1,3-glucanase-like proteins (GLPs), two chitinase-like proteins (CLPs) and two thaumatin-like proteins (TLPs) accumulated during cold acclimation. The proteins in barley leaf apoplast at CA conditions were a little different from those in wheat leaves. The AFPs were various among and within species. More freezing-resistant cultivars had more clear and numerous bands than less freezing-resistant ones. The high determination coefficient ($R^2$ =91 %) between freezing resistance and AFPs per gram leaf fresh weight indicated that the amount of AFPs was highly related to freezing resistance in winter cereal crops.

• BMB Reports
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• v.33 no.5
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• pp.385-390
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• 2000

Overwintering plants should survive the various biotic and abiotic stresses that occur during winter. Previous studies indicated that active oxygen species are involved in freezing, dehydration, anoxia and pathogen infections. As the importance of the events that occur in the intercellular compartment became apparent in disease resistance, we examined the nature of intercellular antioxidant enzymes in order to access their possible involvement in the winter hardiness of barley. The levels of intercellular peroxidase, catalase, and SOD activities on the unit protein basis were 394, 18, and 9% of those of cellular activities, respectively. Major intercellular peroxidase isoforms consisted of four neutrals and four basic forms; whereas major cellular isoforms were two basic forms. Out of the two major catalase isoforms a higher molecular weight form was predominantly abundant in both cellular and intercellular compartments. Among the five major cellular SOD isoforms, three were also present in the intercellular compartment. The presence of substantial amounts of intercellular antioxidant enzymes in overwintering barley leaves may suggest the involvement of these enzymes in the tolerance mechanism to the various stresses that occur during winter.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.156-161
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• 2023

This study was conducted to determine the appropriate seeding dates by verifying the difference in winter survival and productivity of alfalfa according to fall sowing dates in the central area of South Korea. The experiment was conducted for 2 years (2020 and 2021) at the field in the Department of Animal Resources Development, NIAS located in Cheonan. Sowing dates started from September 18 to November 8 with 10 days of intervals during 2020 and 2021; SO1 (September 18), SO2 (September 28), SO3 (October 8), SO4 (October 18), SO5 (October 28), and SO6 (November 8). After sowing, the winter survival rate was measured in the spring of the following year, and the dry matter yield was measured by harvesting at 10% flowering and harvesting five times a year. SO6 failed to winter survival, and SO5 also had a lower winter survival rate than SO1~4 (p<0.05). The average annual dry matter yield of alfalfa linearly decreased with delaying sowing dates (p<0.05). The feed value did not differ in the same year by delaying the sowing date in the same year. These results suggest that sowing date should be started before October 18 to increase winter survival and productivity of alfalfa in the central area of South Korea.

• Animal cells and systems
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• v.7 no.2
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• pp.111-117
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• 2003

Ecological aspects of Cryptocercus kyebangensis life history were investigated via laboratory rearing and field observations. The number of antennal segments and head width were used to classify the first four instars. The results, which combine both the field collection and the laboratory rearing, indicate that eleven instars occur in C. kyebangensis. It supports the proposal on the number of instars of Park and Choe (2003c) based on field collections. A total of 388 nymps from 13 colonies were collected prior to winter to investigate overwintering stages. Of them,4％ (n = 17) were the second instars, 57％ (n = 220) were the third instars, and 39％ (n = 151) were the fourth instars, respectively. Thus, most of them overwinter in the third or fourth instars. The results indicate that young nymphs of C. kyebangensis have to reach at least 3rd or 4th instar to survive low temperature environment of winter. According to seasonal dynamics of populations, C. kyebangensis reaches adulthood in the summer of the fourth or fifth year (4-5 yr span) after their birth.

• Korean System Dynamics Review
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• v.16 no.2
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• pp.53-74
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• 2015

Nutria(Myocastor coypus) is one of the most notorious invasive species in many countries. The Nutria's original range was South America like Brazil, Chile and Argentina. But it has been introduced to North America, Europe, Africa, and Asia including Korea, by fur ranchers. Like most invasive and disturbing species, nutria not only destroys habitats but also impacts many native species throughout most of its range with destructive feeding behavior. The purpose of this study is to investigate the dynamics of survival mechanism, population increase and spatial distribution, and eradication effect of Nutria on Nakdong River Area with the systems thinking. The result of this study revealed that Nutria can survive during winter with the behavior that the colder the winter was, the more deeply it burrowed. Further, the study uncovered the dynamics that nutria has survived more and more strongly during the extreme cold winter in almost every region and their population has increased dramatically as a result of the uncontrolled reproduction. Finally, the result showed that the action delay in eradicating Nutria, which was originated from the information delay of perception of nutria's survival and reproduction structure, reinforced the spread of Nutria across the nation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.340-343
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• 2016

The present study investigated the effects of different seeding rates on growth characteristics and seed productivity of the "Kowinearly" cultivar of Italian ryegrass (Lolium multiflorum Lam.) in paddy fields. Sowing Kowinearly in paddy fields under growing rice at the rates of 20, 30, 40, and 50 kg/ha resulted in seed yields of 1.57, 1.92, 2.06, and 2.09 ton/ha, respectively. Seed yield of Kowinearly was the highest at a seeding rate of 50 kg/ha (p<0.05), at which the cultivar was able to survive in winter and the weed ratio was low. Under these conditions, most growth characteristics such as winter survival (85%), weed ratio (10%), stems per square meter (1,006) were superior than those sown at other seeding rates (p<0.05). In addition, it has been reported that the economic efficiency of the 50 kg/ha seeding rate was higher than that of the other seeding rates.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.560-566
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• 2016

Imports of genetically modified (GM) soybeans (Glycine max) for food or feed consumption in Korea have been increasing. Although the cultivation of GM soybeans has not yet been allowed in Korea, the number of field tests for GM soybeans has also been rising. This study was conducted to investigate whether herbicide tolerant GM soybean can survive and persist in uncultivated environments when they escape from transportation routes or from isolated fields. Seeds of GM and non-GM soybeans and wild soybeans (Glycine soja) were buried in 2 and 15 cm soil depths and their viability was examined after 1, 2, 6, and 10 months. GM and non-GM soybean seeds completely lost their viability within six months of burial, whereas seeds of wild soybean maintained their viability during the study period. Seeds of soybean and wild soybeans that were sown on the soil surface germinated and grew to vegetative cotyledon stage. Seedlings of GM and non-GM soybean did not compete well with weeds, including Cerastium glomeratum, Alopecurus aequalis var. amurensis, Capsella bursa-pastoris, Conyza canadensis, Stellaria aquatica, and Erigeron annuus. Also, GM soybean did not survive through winter. However, wild soybeans competed well with the weeds and became dominant in August. Herbicide tolerant GM soybean is unlikely to persist under uncultivated environments and to become weeds.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.287-293
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• 2014

Matsumuraeses phaseoli is one of the main pests that attack the flowers and pods of red bean (Vigna angularis) and mungbean (Vigna radiata) in Korea. To elucidate the developmental characteristics and over-wintering stage of M. phaseoli, several stages of the insect were observed through artificial rearing under outdoor conditions in Suwon ($37^{\circ}$16'N $126^{\circ}$59'E 35ASL), Korea. In colonies in which neonate larvae were reared at about 2-week intervals for more than a year, the developmental period from larva to adult emergence became longer from spring to summer, but shorter from summer to autumn; aestivation was not observed during the summer season. The colony in which rearing started on Oct 8, 2008 over-wintered as pupae and emerged in late April next year with a survival rate of 6%. However, the colony in which the rearing started on Oct 23, 2008 over-wintered as mature larvae, pupated in late April, and emerged in early and mid-May with a survival rate of 2%. When the fifth instar larvae were transferred outside from the laboratory ($25^{\circ}C$, 15L:9D) between November and February, no larvae could survive during the winter season. Some newly laid eggs and newly emerged adults could not hatch and could not survive, respectively, in outdoor conditions in November and December. These results suggest that neonate larvae of M. phaseoli that hatch in October can over-winter as late larvae or pupae in Suwon, Korea.

• The Korean Journal of Mycology
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• v.5 no.1
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• pp.33-37
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• 1977

This study was made in order to determine which Gibberella species were occurring on rice stems and seeds in the field, and their survival 5 months after harvest time. An average 12% of plants infected with 'Bakanae' disease occurred in 4 fields planted with non-treated seed. Prior to harvest, more perithecia of Gibberella moniliformis occurred on infected rice stems than of Gibberella rosea. But Gibberella rosea was most common on the seed, and perithecia of this species also survived best until spring. F. moniliforme, F. roseum and Ophiobolus sp. were isolated from seedlings planted from naturally infected seed at the rates of 10, 25 and 8% respectively and from infected stems at rates of 3, 10 and 2% respectively. Perithecia of Gibberella rosea survived through the winter on naturally infected rice stems when kept dry indoors, buried in field soil, or places in straw stackes in the field. They did not survive on straw left on the soil surface during the very cold and dry conditions of the 1976-'77 winter.

• Korean Journal Plant Pathology
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• v.2 no.1
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• pp.17-21
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• 1986

The viruliferous vectors of the rice dwarf virus, nymphs of Nephotettix cincticeps did not overwinter in Uljin, although the disease occurred in fields. When considered the relationship between seasonal changes of vector and disease occurrence, there were 5 and 3 peaks in a year in occurrence of vector and disease, respectively. The over­wintered adults and the nymphs of the 2nd and 3rd generation served as the major transmittor of the. virus. In a field where the disease has been a problem for years, the ratoon hills rice cultivar Milyang No. 30 was infected $22.4\~26.8\%$ with the rice dwarf virus. When nonviruliferous nymphs were fed on the infected ratoon hills for 11 to 30 days, viruliferous nymphs overwintered, increased to $13.0\~18.2\%$. The winter barley infected with rice dwarf virus did not survive in winter, suggesting that infected barley may not serve as a inoculum source.