• Journal of Life Science
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• v.9 no.1
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• pp.69-75
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• 1999

Four species belonging to the Drosophila melanogaster complex were examined genetically and morphologically to analyze interspecific relationships. Insemination rates ranged from 96% to 99% within species crosses, but interspecific crosses among the four species exhibited a great variations in the frequency of successful matings. D. melanogaster females mated relatively well with males of other species and D. sechellia males were more successful in mating with females of other species. In the crosses among D. simulans, D. mauritiana and D. sechellia, hybrid flies were fertile in females, but sterile in males regardless of reciprocal matings. The phenogenetically relationship between this complex and their hybrids were investigated by the comparison of sex comb tooth number and genital arch of male. They were controlled by polygenic factors on the chromosome of both parents. The effects of temperature on viability of hybrids between D. melanogaster females and D. simulans males were investigated for detection of genes concerning the speciation. The temperature sensitivity of the hybrid was mainly controlled by genes located on the X chromosome of D. simulans males.

• Journal of Marine Life Science
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• v.2 no.2
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• pp.83-89
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• 2017

In abalones, interspecific hybridization has been suggested as a possible means to increase production and desired traits for the industry. In Korea, Haliotis gigantea is considered a species with a larger size and higher temperature tolerance than H. discus hannai. However, H. discus hannai is considered the most valuable and popular fishery resource due to its better acceptance and higher market prices. Thus, viable interspecific hybrids have been produced by artificial inseminating H. gigantea eggs with H. discus hannai sperm. However, the reciprocal hybrid cross was not successful. In this study, the hybridity and the growth and thermal tolerance performance of the interspecific hybrids were examined. A combination of various assays revealed maximum growth occurrence at 21℃ and the higher growth rate in the hybrids than that of H. discus hannai parent. In addition, the growth and survival at high-temperature (28℃) of the hybrids was equivalent to that of the highly tolerant H. gigantea parent, suggesting new possibilities to overcome the mass mortality in H. discus hannai during high temperature periods of summer season in Korea. Furthermore, the induced interspecific hybrid status was confirmed by the presence of species-specific bands for each parental species of the random amplified polymorphic DNA (RAPD) profiles using universal rice primer (URP), which could be used as speciesspecific markers to distinguish the hybrids and their parental species.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.191-191
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• 2022

Heterostyly continues to fascinate evolutionary biologists interested in heredity, evolution, breeding, and adaptive function. Polymorphism demonstrates how simply inherited developmental changes in the location of plant sexual associations can have important consequences for population pollination and mating biology. In contrast to homozygous self incompatibility, only a small number of mating phenotypes can be maintained in the population because insect pollinators have limitations in achieving multiple segregation sites for pollen deposition. Field studies of pollen tube growth have shown that reciprocal style-stamen polymorphisms function to increase the capacity of insect-mediated cross-pollination. The genetic pattern of style morphs is well established in various taxa, but despite recent advances, the identity, number, and structure of the genes controlling the heteromorphic syndrome have been poorly elucidated. The phenomenon of heterostyly in buckwheat has been controlled by gene complex concentrate to S-locus. Homomorphic autogamous buckwheat strains were established by the interspecific hybridization. Backcrossing of this line to the common buckwheat (pin) and selecting homostylar progenies made it possible to introduce the self-compatible gene into common buckwheat. In the result, we obtained the BC₉F₂ generation, and defined the strong linkage between flower type and self-incompatibility by microscopic observation of pollen tube growth. This finding suggests that self-incompatibility character is not controlled by one gene. Moreover, we defined the strong linkage between flower type and self-incompatibility. It strongly supports the S supergene theory. Therefore, we have plan to elucidate the heterostyly self-incompatibility by using molecular genetics, proteome analysis and apply to exploitation of buckwheat improvement. In near future, the expression of heterozygous syndromes in genus Fagopyrum with single isolated heterozygous species may provide clues to early stages of polymorphic assembly and shed light on evolutionary models of heterozygous strains.

• Journal of the Economic Geographical Society of Korea
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• v.26 no.3
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• pp.256-273
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• 2023

This study analyzed the structural changes in the global foreign direct investment (FDI) network using stock data from the International Monetary Fund's Coordinated Direct Investment Survey (CDIS) for 2009~2021. The results showed that the COVID-19 pandemic had a negative impact on the FDI links between countries and the activities of reciprocal relationships. The United States, the Netherlands, and the United Kingdom consistently play central roles in the global FDI network. The degree centrality of China has changed significantly over time in confronting the volatile situation of the world economy. Cross-tabulation analysis revealed a significant association between FDI clusters and geographic regions. Within each cluster, the linkage structure of FDI partners of closely connected individual countries has exhibited differential characteristics as the global economic environment changes.

• Korean Journal of Plant Resources
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• v.15 no.3
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• pp.177-187
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• 2002

In our experiment, selected mutants were used which showed not only the phenotype of a specific unpolished rice but also phenotypes of EM 40, LO 1050, and TAL 214. Reciprocal crosses between the mutants were conducted to select strains which would have more quantity of lipids than before. The constitution of fatty acid was also tested to figure out nutritional aspects of the mutants. In the crossing between EM 40 mutants and mutants (LO 1050) having a thick aleurone layer, the expression of EM 40 mutants has no relation with the thickness of the aleurone layer. And the lipid content of new F$_2$ strains through the crossing is 4.15 ％. The lipid content is larger than those of the parents including Kinmaze and in other crossings of this experiment. This is attributed to the fact that the new F$_2$ strains are the products of the crossing between genes responsible for the size of buds, where lipid is accumulated, and genes accountable for the thickness of the aleurone layer. In the crossing between EM 40 mutants and TAL 214 mutants, lipid content of the new F$_2$ strains is 3.8 ％, higher than 2.92 ％ of TAL 214 mutants. But the degree of lipid increase is smaller than in two other crossings. This is probably because genes expressing the phenotypes of TAL 214 affect the size of EM 40, which gets smaller. The aleurone layer of the new F$_2$ strains is 12 $\mu\textrm{m}$ thicker than the layer of TAL 214 mutants, but 6 $\mu\textrm{m}$ thinner than that of parents (LO 1050) having a thick aleurone layer. This seems to be affected by the size of a microscope. The phenotype of the new F$_2$ strains appears to be similar to that of TAL 214. The lipid content of the new F$_2$ strains is 3.85 ％, larger than 2.92 ％ of TAL 214 and 3.01 % of LO 1050. The increase may be due to the aleurone layer of LO 1050. And the size of the bud of the unpolished rice, though it is not big enough like that of LO 1050, seems to be affected by the accumulation of genes in the thick aleurone layer. The accumulation may contribute to the increase in the content of lipid. When it comes to the constitution of fatty acid, there is little difference between parents like Kinmaze and the new F$_2$ strains. But oleic acid increases while linoleic acid decreases. And the decrease in the linolenic acid seems to contribute to the increase in lipid content. This fact also raises the possibility that genes accountable for specific phenotypes could change the quality of rice if the genes are accumulated. Now, experiments on strains which have large lipid content in EM 40 type 1(ge-1, 3.68 ％), EM type 2(ge-2, 2.91 ％), thick aleurone layer(4.63 ％), and starch layer(3.44 ％) are under way to figure out the effects of gene accumulation. These experiments are likely to present the ways for increasing the lipid content.

• Korean journal of applied entomology
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• v.40 no.4
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• pp.337-344
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• 2001

The house fly (Musca domestica L.) strains were derived from the Yumenoshima III strain by selecting with cypermethrin and methomyl for 19 and 16 generations, respectively. The resulting strains, cypermethrin resistance strain (Cyp-R19) and methomyl resistance strain (Met-R16), showed high level of resistance by 12906 and 51 times, respectively, comparing with the susceptible SRS strain. The Cyp-R19 strain was resistant to synthetic pyrethroids such as deltamethrin, esfenvalerate, fenpropathrin, $\beta$-cyfluthrin, showing > 11000, 1231, 103, 292 times higher $LD_{50}$ values than the SRS strain, respectively. It was also resistant to 3 organophosphates and 2 carbamates such as fenitrothion, profenofos, pyridaphenthion, benfuracarb, methomyl, showing resistance ratios fo 51, 17, 49, 39 and 62 comparing to SRS strain. The Met-R16 strain was resistant to synthetic carbamate benfuracarb, showing 6 times higher $LD_{50}$ value than SRS strain. It was also resistant to 4 organophosphates such as acephate, fenitrothion, profenofos and pyridaphenthion, showing > 40, 103, 19, 60 times higher $LD_{50}$ value. It was also resistant to 5 pyrethroids and a pyrrole such as cypermethrin, deltamethrin, esfenvalerate, fenpropathrin, $\beta$-cyfluthrin and chlorfenapyr, showing 3030, 249, 4063, 34, 330 and 86 times higher $LD_{50}$ values than the SRS strain. Cyp-R14 strain which was selected for 14 generations by cypermethrin and developed 11014 times higher resistance to the SRS strain was used in the dominance and linkage group analysis. Cypermethrin resistance inheritance was incompletely dominant in house fly as judged by the reciprocal cross between the resistant and susceptible strains. The linkage group analysis for the major factors responsible for this resistance was carried out by the$ F_1$male-backcross method, using susceptible multi-chromosomal marker aabys strain. The major factors for cypermethrin resistance were located on the 1st, the 3rd and the 4th chromosomes, and the effect of the 3rd chromosome was most prominent.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.305-312
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• 1992

This experiment was carried out to investigate seed set, variation in chromosome number, and agronomic characteristics of the progeny in the cross between hexaploid triticale variety, Sinkihomil(P$_1$) and tetraploid rye variety, Dooroohomil(P$_2$). Seed set rate obtained was 30.5% in the cross of Sinkihomil with Dooroohomil, whereas 3.26% in reciprocal cross using Dooroohomil as female. Alsoseed set was 8.75% in F$_1$/P$_1$, 7.20% in F$_1$/P$_2$, and 1.53% in F$_2$(=F$_1$ /F$_1$, respectively. Germination rate of crossed seed was 37% in cross of P$_1$ with P$_2$, 39.0% in F$_1$/P$_1$(BC$_1$), 50% in F$_1$/P$_2$(BC$_2$) and 43.0% in F$_1$/F$_1$(F$_2$), and 1,000 grain wight was 20.7g in the cross of P$_1$ with P$_2$, which have 41.9g and 47.7g, respectively, 24.5g in F$_1$/P$_1$, 23.6g in F$_1$/P$_2$, and 24.5g in F$_1$/F$_1$, respectively. In pollen fertility of F$_1$ plant, 69.8% turned out to be abnormal or sterile pollen grains, whereas 30.2% was fertile or normal. In meiosis of pollen mother cell of F$_1$ plant, 13.5 univalents, 8.89 bivalent and 1.24 trivalent were appeared. Somatic chromosome number of 35 in F$_1$, both 32 to 33 and 35 to 36 in F$_2$, 35 to 39 in BC$_1$ and 28 to 36 in BC$_2$ which mean producing female gamate was 14 to 18 chromosome in PMC of F$_1$ plant. Rate of fertile plant turned out to be 100% in F$_1$, 4.5% in F$_2$, 42.9% in BC$_1$, and 50.0% in BC$_2$, respectively. Number of seed set per spike appeared to be 1.17 in F$_1$ plant, 13.3 in F$_2$, 2.36 in BC$_1$, and 3.75 in BC$_2$, respectively. Days to heading of F$_1$ was intermediate, but F$_2$ was later than both parents. Plant height of F$_1$ , BC$_1$ ,and BC$_2$ was shorter than both parent, but F$_2$, longer than both parents.

• Journal of The Korean Association For Science Education
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• v.42 no.3
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• pp.371-381
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• 2022

This study causally investigates whether high school student with high science learning motivation becomes to achieve more or vice versa, and also how those two factors affect STEM career motivation. Research participants were 1st year students in a high school at Seoul. We surveyed their science learning motivation three times in the same time interval in the fall semester of 2021, and once a STEM career motivation in the third period. We collected data from 171 students with their mid-term and final exam scores, with which, we constructed and fitted an autoregressive cross-lagged model. The research model shows high measurement stability and fit indices. All the autoregressive and cross-lagged paths were statistically significant. However, standardized regression coefficients were larger in path from motivation to achievement compared to the opposite. Only science learning motivation shows significant direct effect on STEM career motivation, rather than achievement. For indirect effects, the first science learning motivation affected the final exam score and STEM career motivation, and the final exam score affected STEM career motivation. However, the final exam score did not have a total effect toward STEM career motivation. The result of this study shows reciprocal and cyclic causality between science learning motivation and achievement - in comparison, the effect of motivation for the opposite is larger than that of achievement. Also the result of this study strongly reaffirms the importance of science learning motivation. Instructional implications for strengthening science learning motivation throughout a semester was discussed, and a study for the longitudinal effect of science learning motivation and achievement in high school student toward future STEM vocational life was suggested.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.378-383
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• 2001

Embryo culture, ovule culture and ovary slice culture were tested to find optimum method for overcoming post fertilization barrier in interspecific crosses between L. longiflorum 'Gelria' and L. cernuum. Although reciprocal crosses between the species were carried out by cut-style pollination method, fruits developed only in crosses of L. longiflorum${\times}$L. cernuum. On the 40 days after pollination, ovaries were sliced into 2-4mm thickness and cultured on a hormone-free Murashige-Skoog (MS) medium, supplemented with 2%, 4%, 6%, 8% and 10% sucrose. For the L. longiflorum Gelria'${\times}$L. cernuum cross, ovule development was found to be best at 6% sucrose and a lot of hybrid plant lets established directly from the ovary slice culture and subsequent ovule culture. High concentration of sucrose above 8% made ovules abort or vitrificate from 40 days after culture. In contrast, ovules from the L. cernuum${\times}$L. longiflorum 'Gelria' cross swelled well in ovary slice culture, however, they did not germinated in subsequent ovule culture. On the 60 days after pollination, ovules thicker than 0.6mm was interpreted as one containing embryo. The embryo size ranged from 1.2 mm to 1.7 mm, and in vitro development of the excised embryos was found to be best with the MS medium (pH 5.8), supplemented with $0.1-1 mg{\cdot}L^{-1}$ NAA and 6% sucrose. Thick ovules excised 60 days after pollination germinated about 60% as normal seeds in MS medium supplemented with 6% sucrose and free hormone. The ovule culture 60 days after pollination was concluded to be most recommendable to produce interspecific hybrids in large scale crosses between L. longiflorum 'Gelria' and L. cernuum by the reason of easy procedure.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.543-548
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• 2012

Morphological characters of Baemoochae, xBrassicoraphanus are mostly intermedium of the both parents, Chinese cabbage, Brassica rapa ssp. pekinensis and radish, Raphanus sativus. The upper and lower parts of the leaf resemble the shape of Chinese cabbage and radish, respectively. The midrib of the leaf is round like to that of radish, but very big more than 3 cm in diameter and white in color like that of Chinese cabbage. The root was changed from the swollen type like that of radish to the enlarged taproot like that of the land race of Chinese cabbage after attaining genetical stability. The flower is white. The seed pod is divided into 2 different parts; the upper part is radish and about 4 cm in length and holds 3-4 seeds and the lower part is Chinese cabbage and about 3 cm in length and holds 7-8 seeds. The color of seed is brown, weight per 1.000 seeds is 5.5 g and the number of seeds per mL is 120. The matured plant in the fall season is around 5 kg in weight and outer leaves are very vigorous and stiffly and inner leaves are erect and form a loose head. The leaf and the root contain a high level of sulforaphene which is well known as a functional substance for anti-cancer and anti-super-bacteria. Baemoochae is an amphidiploid and does not have the self incompatibility function. It has a high level of cross compatibility with Chinese cabbage as the female parent, but not the male parent. It is cross incompatible to cabbage, B. oleracea, black mustard, B. nigra and radish. However it is highly compatible to oil seed rape, B. napus, yellow mustard, B. carinata and partial compatible to muatard, B. juncea in the reciprocal cross.