• 한국균학회소식:학술대회논문집
• /
• 2014.10a
• /
• pp.32-32
• /
• 2014

Meju is a brick of dried fermented soybeans and is the core material for Jang such as Doenjang and Ganjang. Jang is produced by addition of salty water to Meju and is considered the essential sauces of authentic Korean cuisine. Meju is fermented by diverse microorganisms such as bacteria, fungi and yeasts. It is known that fungi play an important role in the Meju fermentation and they degrade macromolecules of the soybeans into small nutrient molecules. In previous study, 26 genera and 0 species were reported as Meju fungi. However, it is not comprehensively examined where the fungi present on the Meju are originated. In order to elucidate the origin of the fungi present on the Meju, the mycobiota of 500 samples soybean kernels, 296 rice straw pieces and air samples of Jang factories was determined in 0, 2 and 7 Jang factories respectively. Forty-one genera covering 86 species were isolated from the soybeans and 33 species were identical with the species from Meju. From sodium hypochlorite untreated soybeans, Eurotium herbariorum, Eurotium repens, Cladosporium tenuissimum, Fusarium fujikuroi, Aspergillus oryzae/flavus and Penicillium steckii were the predominant species. In case of sodium hypochlorite-treated soybeans, Eurotium herbariorum, E. repens and Cladosporium tenuissimum were the predominant species. Of the 4 genera and 86 species isolated from soybeans, 3 genera and 33 species were also found in Meju. Thirty-nine genera and 92 species were isolated from the rice straws and 40 species were identical with the species from Meju. Fusarium asiaticum, Cladosporium cladosporioides, Aspergillus tubingensis, A. oryzae, E. repens and Eurotium chevalieri were frequently isolated from the rice straw obtained from many factories. Twelve genera and 40 species of fungi that were isolated in the rice straw in this study, were also isolated from Meju. Especially, A. oryzae, C. cladosporioides, E. chevalieri, E. repens, F. asiaticum and Penicillium polonicum that are abundant species in Meju, were also isolated frequently from rice straw. C. cladosporioides, F. asiaticum and P. polonicum that are abundant in low temperature fermentation process of Meju fermentation, were frequently isolated from rice straw incubated at $5^{\circ}C$ and $25^{\circ}C$, while A. oryzae, E. repens and E. chevalieri that are abundant in high temperature fermentation process of Meju fermentation, were frequently isolated from rice straw incubated at $25^{\circ}C$ and $35^{\circ}C$. This suggests that the mycobiota of rice straw have a large influence in mycobiota of Meju. Thirty-nine genera and 92 species were isolated from the air of Jang factories and 34 species were identical with the species from Meju. In outside air of the fermentation room, Cladosporium sp. and Cladosporium cladosporioides were the dominant species, followed by Cladosporium tenuissimum, Eurotium sp., Phoma sp. Sistotrema brinkmannii, Alternaria sp., Aspergillus fumigatus, Schizophyllum commune, and Penicillium glabrum. In inside air of the fermentation room, Cladosporium sp., Aspergillus oryzae, Penicillium chrysogenum, A. nidulans, Aspergillus sp., C. cladosporioides, Eurotium sp., Penicillium sp., C. tenuissimum, A. niger, E. herbariorum, A. sydowii, and E. repens were collected with high frequency. The concentrations of the genus Aspergillus, Eurotium and Penicillium were significantly higher in inside air than outside air. From this results, the origin of fungi present on Meju was inferred. Of the dominant fungal species present on Meju, Lichtheimia ramosa, Mucor circinelloides, Mucor racemosus, and Scopulariopsis brevicaulis are thought to be originated from outside air, because these species are not or are rarely isolated from rice straw and soybean; however, they were detected outside air of fermentation room and are species commonly found in indoor environments. However, A. oryzae, P. polonicum, E. repens, P. solitum, and E. chevalieri, which are frequently found on Meju, are common in rice straw and could be transferred from rice straw to Meju. The fungi grow and produce abundant spores during Meju fermentation, and after the spores accumulate in the air of fermentation room, they could influence mycobiota of Meju fermentation in the following year. This could explain why concentrations of the genus Aspergillus, Eurotium, and Penicillium are much higher inside than outside of the fermentation rooms.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.59 no.2
• /
• pp.151-161
• /
• 2014

Sesame lignan, including sesamin and sesamolin has been reported to have various content according to accessions and environmental factors. The objective of this study were to analyze the lignan variation of 143 sesame accessions from core collection in Korea and to test the effects of growing years and locations on lignan and lipid content of Korea sesame elite lines. The results showed that the core sesame germplasm in Korea has broad variation of lignan content from 2.33 to 12.17 mg/g with an average 8.18 mg/g. Among tested sesame accessions, the IT184615 had the highest lignan content of as 12.17 mg/g. So this accession will be a good genetic resource for developing a high lignan sesame variety. The sesamin and sesamolin content for sesame accessions across origin had significant difference. The average lignan content of accessions collected from Russia (10.0 mg/g) and Nepal (9.08 mg/g) were relatively higher than other countries. The sesamin and sesamolin content for sesame accessions across seed coat color had significant difference. The average lignan content of sesame with white, brown and black seed coat color was 8.61, 7.51, and 5.49 mg/g, respectively. The variation of lignan and lipid content was significantly different across elite lines, locations and growing years. Therefore, it is important to find sesame accessions having high lignan content with environmental stability.

• Journal of Korean Academy of Nursing
• /
• v.26 no.2
• /
• pp.257-270
• /
• 1996

Studies on menstruation have focused only on menstruation itself and menstrual disorders. The menstruating girls or women have been neglected. So, the purpose of this study was to understand menstrual experience of adolescent girls in their perspective and build a theory on it, The specific purpose of this study were to find initial reaction of the girls, their strategies to adapt to menstruation. consequences of their efforts, influencing factor, and patterns of experience. The subjects of this study were eleven adolescent girls who experienced menarche three months to twenty-six months before the interview time. They were selected purposively. Their ages were in range of twelve and sixteen. One of them was a elementary school girl, three high school girls, and seven middle school girls. Two girls were handicapped because of cerebral palsy. All of them had some knowledge about menstrual physiology and hygiene during menstruation. Data were collected from September, 1994 to July, 1995. Data collection ＆ analysis were done according to the grounded theory methodology by Strauss ＆ Corbin(1990). Data collecting method was the long interviews and observation. Each interview took from 1 hour to 2 hours. Interview were tape-recorded and transcribed later by author. Data were analyzed immediately after interviews. Based on the results of previous interview, next interview were planned until gathered data reached the saturation point. Results were as follows. One hundred and six concepts were found. Those concepts were grouped into twenty eight categories and then fourteen higher categories. Twenty eight categories were as follows. “want to hide”, “bewildered”, “sense of burden”, “sense of heterogeneity”. “gladness”. “sense of superiority”, “negative empathy”, “positive empathy”, “limited hygenic control”, “sense of timing”, “lack of knowledge”, “lack of support”, “advance knowledge”, “informational support”, “emotional support”, “endurance”, “prayer”, “disclosing”, “avoidance”, “diversion”, “sense of powerlessness”, “discovery of sex identity”, “sense of maturation”, “sense of stability”, “acceptance of menstruation ”. fourteen higher categories were as follows. “negative feeling”, “posive feeling”, “exchange of feeling”, “limited hygenic control”, “sense of timing”, “accumulated experience”, “dysmenorrhea”, “level of knowledge”, “need for support”, “perceived support”, “sharing of feeling”, “self-control”, “passive acceptance”, “active acceptance”. The core category was “emotional shaking”, which consisted of “positive feeling” and “negative feeling”. “Emotional shaking”comes up to every adolescent girls experiencing menarche, independently of any contextual conditions, and its dimension has two directions : positive one and negative one. Its influencing factors were time of menarche, advance knowledge, support from the significant persons, expression and self-regulation. Even if they showed different process of adaptation to menstruation, general process of adaptation were as follows : 1. stage of emotional shaking 2. stage of acceptance 3. stage of internalization of the menstrual experience. Seven patterns existed on the process of adaptation to menstruation after menarche. Those are as follows. 1. If girls thought their menarche came too early and they had not much knowledge on menstruation, they had a kind of negative feeling. If they did not get enough support and dysmenorrhea superimposed, they came to accept menstruation passively. 2. If girls had menarche too early. they had negative feeling, even though they had enough advance knowledge. But support helped them accept menstruation easily. 3. If girls had menarche too early, they had negative feeling, even though they had enough advance knowledge on menstruation. But by experiencing subsequent menstruations and disclosing feeling, they began to accept menstruation. 4. If girls had menarche too lately and they had enough advance knowledge on menstruation. they had positive feeling. If dysmenorrhea superimposed later, their feeling turned in to negative one. But they came to accept menstruation positively by disclosing feeling and getting support. 5. If girls had menarche too early, they had negative feeling, even though they had enough advance knowledge on menstruation. In addition to this. if dysmenorrhes superimposed while they did not get enough support, they felt powerless and came to accept menstruation passively. 6. If girls had menarche too early and did not get enough advance knowledge, they had negative feeling. But disclosing feeling and support made them get sense of homogeneity and began to accept menstruation. 7. If girls had handicap, they had negative feeling, even though they had enough advance knowledge and menarche was late. But Menarche made them get feel sexual identity. Their limited hygenic control and negative empathy from their mothers made them accept menstruation passively. To let adolescent girls take their menstrual experience as a part of their lives forming a positive sense of feminine identity, it needs qualified teaching and, support and deep concern of the significant others. Nurses including school nurses should try to develop an educational program, which include menstrual physiology. hygiene during menstrual period, meaning of menstruation and impact of menstruation on the development of female sexual identity.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.10 no.3
• /
• pp.171-183
• /
• 2015

Unlike the over 60 years American history of entrepreneurship education, in spite of its short history Korean entrepreneurship education has been rapidly developing. These rapid growth of background, founding activation of for a creative economy realization of core policy of aggressive entrepreneurship education assistance policy and the new government ministries and agencies of government, and growth and global and recession without employment the can and the like or the importance of all the national foundation through. Moreover, the entrepreneurship education came into universities, can not be considered in isolation now academic part of foundation. This study focuses on the analysis the past history of entrepreneurship education based on a variety of data collection. And the analysis is based on three parts; the status of domestic entrepreneurship education, entrepreneurship courses and entrepreneurship research. The result shows that domestic entrepreneurship education is being developed and spread rapidly. Moreover, the number of entrepreneurship courses are increased exponentially in addition to research activities that can contribute to the development of entrepreneurship are also actively performed. Until 2013 the number of entrepreneurship courses opened in universities is 57 times more in last 21 years, meaning that entrepreneurship education is expanding rapidly. In addition, the 142 various journals in domestic are publishing with a research topic related to entrepreneurship, comparing the 44 US journals researching primarily on entrepreneurship, and we can also expect the future growth of domestic research field. This study gives the implication on the field of entrepreneurship education, entrepreneurship courses and entrepreneurship research based on the analysis of existing studies and related materials for the history of entrepreneurship education. With the result of the analysis this study may contribute to entrepreneurship education and research in Korea, and also give insight for nurturing entrepreneurship culture and spirits.

• Asia pacific journal of information systems
• /
• v.17 no.4
• /
• pp.207-228
• /
• 2007

Measuring Information Technology(IT) organizations' activities have been limited to mainly measure financial indicators for a long time. However, according to the multifarious functions of Information System, a number of researches have been done for the new trends on measurement methodologies that come with financial measurement as well as new measurement methods. Especially, the researches on IT Balanced Scorecard(BSC), concept from BSC measuring IT activities have been done as well in recent years. BSC provides more advantages than only integration of non-financial measures in a performance measurement system. The core of BSC rests on the cause-and-effect relationships between measures to allow prediction of value chain performance measures to allow prediction of value chain performance measures, communication, and realization of the corporate strategy and incentive controlled actions. More recently, BSC proponents have focused on the need to tie measures together into a causal chain of performance, and to test the validity of these hypothesized effects to guide the development of strategy. Kaplan and Norton[2001] argue that one of the primary benefits of the balanced scorecard is its use in gauging the success of strategy. Norreklit[2000] insist that the cause-and-effect chain is central to the balanced scorecard. The cause-and-effect chain is also central to the IT BSC. However, prior researches on relationship between information system and enterprise strategies as well as connection between various IT performance measurement indicators are not so much studied. Ittner et al.[2003] report that 77% of all surveyed companies with an implemented BSC place no or only little interest on soundly modeled cause-and-effect relationships despite of the importance of cause-and-effect chains as an integral part of BSC. This shortcoming can be explained with one theoretical and one practical reason[Blumenberg and Hinz, 2006]. From a theoretical point of view, causalities within the BSC method and their application are only vaguely described by Kaplan and Norton. From a practical consideration, modeling corporate causalities is a complex task due to tedious data acquisition and following reliability maintenance. However, cause-and effect relationships are an essential part of BSCs because they differentiate performance measurement systems like BSCs from simple key performance indicator(KPI) lists. KPI lists present an ad-hoc collection of measures to managers but do not allow for a comprehensive view on corporate performance. Instead, performance measurement system like BSCs tries to model the relationships of the underlying value chain in cause-and-effect relationships. Therefore, to overcome the deficiencies of causal modeling in IT BSC, sound and robust causal modeling approaches are required in theory as well as in practice for offering a solution. The propose of this study is to suggest critical success factors(CSFs) and KPIs for measuring performance for IT organizations and empirically validate the casual relationships between those CSFs. For this purpose, we define four perspectives of BSC for IT organizations according to Van Grembergen's study[2000] as follows. The Future Orientation perspective represents the human and technology resources needed by IT to deliver its services. The Operational Excellence perspective represents the IT processes employed to develop and deliver the applications. The User Orientation perspective represents the user evaluation of IT. The Business Contribution perspective captures the business value of the IT investments. Each of these perspectives has to be translated into corresponding metrics and measures that assess the current situations. This study suggests 12 CSFs for IT BSC based on the previous IT BSC's studies and COBIT 4.1. These CSFs consist of 51 KPIs. We defines the cause-and-effect relationships among BSC CSFs for IT Organizations as follows. The Future Orientation perspective will have positive effects on the Operational Excellence perspective. Then the Operational Excellence perspective will have positive effects on the User Orientation perspective. Finally, the User Orientation perspective will have positive effects on the Business Contribution perspective. This research tests the validity of these hypothesized casual effects and the sub-hypothesized causal relationships. For the purpose, we used the Partial Least Squares approach to Structural Equation Modeling(or PLS Path Modeling) for analyzing multiple IT BSC CSFs. The PLS path modeling has special abilities that make it more appropriate than other techniques, such as multiple regression and LISREL, when analyzing small sample sizes. Recently the use of PLS path modeling has been gaining interests and use among IS researchers in recent years because of its ability to model latent constructs under conditions of nonormality and with small to medium sample sizes(Chin et al., 2003). The empirical results of our study using PLS path modeling show that the casual effects in IT BSC significantly exist partially in our hypotheses.

• Journal of Intelligence and Information Systems
• /
• v.17 no.3
• /
• pp.131-146
• /
• 2011

It is becoming more essential than ever for office professionals to become competent in information collection/gathering and problem solving in today's global business society. In particular, office professionals do not only assist simple chores but are also forced to make decisions as quickly and efficiently as possible in problematic situations that can end in either profit or loss to their company. Since office professionals rely heavily on their tacit knowledge to solve problems that arise in everyday business situations, it is truly helpful and efficient to refer to similar business cases from the past and share or reuse such previous business knowledge for better performance results. Case-based reasoning(CBR) is a problem-solving method which utilizes previous similar cases to solve problems. Through CBR, the closest case to the current business situation can be searched and retrieved from the case or knowledge base and can be referred to for a new solution. This reduces the time and resources needed and increase success probability. The main purpose of this study is to design a system called COKRS(Case-based reasoning Office Knowledge Recommender System) and develop a prototype for it. COKRS manages cases and their meta data, accepts key words from the user and searches the casebase for the most similar past case to the input keyword, and communicates with users to collect information about the quality of the case provided and continuously apply the information to update values on the similarity table. Core concepts like system architecture, definition of a case, meta database, similarity table have been introduced, and also an algorithm to retrieve all similar cases from past work history has also been proposed. In this research, a case is best defined as a work experience in office administration. However, defining a case in office administration was not an easy task in reality. We surveyed 10 office professionals in order to get an idea of how to define a case in office administration and found out that in most cases any type of office work is to be recorded digitally and/or non-digitally. Therefore, we have defined a record or document case as for COKRS. Similarity table was composed of items of the result of job analysis for office professionals conducted in a previous research. Values between items of the similarity table were initially set to those from researchers' experiences and literature review. The results of this study could also be utilized in other areas of business for knowledge sharing wherever it is necessary and beneficial to share and learn from past experiences. We expect this research to be a reference for researchers and developers who are in this area or interested in office knowledge recommendation system based on CBR. Focus group interview(FGI) was conducted with ten administrative assistants carefully selected from various areas of business. They were given a chance to try out COKRS in an actual work setting and make some suggestions for future improvement. FGI has identified the user-interface for saving and searching cases for keywords as the most positive aspect of COKRS, and has identified the most urgently needed improvement as transforming tacit knowledge and knowhow into recorded documents more efficiently. Also, the focus group has mentioned that it is essential to secure enough support, encouragement, and reward from the company and promote positive attitude and atmosphere for knowledge sharing for everybody's benefit in the company.

• Economic and Environmental Geology
• /
• v.53 no.1
• /
• pp.23-32
• /
• 2020

Geological CO₂ sequestration is a global warming response technology to limit atmospheric emissions by injecting CO₂ captured on a large scale into deep geological formations. The presented results concern mineralogical and hydrogeological investigations (FE-SEM, XRD, XRF, and MICP) of mudstone samples from drilling cores of the Pohang basin, which is the research area for the first demonstration-scale CO₂ storage project in Korea. They aim to identify the mineral properties of the mudstone constituting the caprock and to quantitatively evaluate the hydrogeologic sealing capacity that directly affects the stability and reliability of geological CO₂ storage. Mineralogical analysis showed that the mudstone samples are mainly composed of quartz, K-feldspar, plagioclase and a small amount of pyrite, calcite, clay minerals, etc. Mercury intrusion capillary pressure analysis also showed that the samples generally had uniform particle configurations and pore distribution and there was no distinct correlation between the estimated porosity and air permeability. The allowable CO₂ column heights based on the estimated pore-entry pressures and breakthrough pressures were found to be significantly higher than the thickness of the targeting CO₂ injection layer. These results showed that the mudstone layers in the Yeongil group, Pohang basin, Korea have sufficient sealing capacity to suppress the leakage of CO₂ injected during the demonstration-scale CO₂ storage project. It should be noticed, however, that the applicability of results and analyses in this study is limited by the lack of available samples. For rigorous assessment of the sealing efficiency for geological CO₂ storage operations, significant efforts on collection and multi-aspect evaluation for core samples over entire caprock formations should be accompanied.

• Journal of Korean Society of Transportation
• /
• v.22 no.7 s.78
• /
• pp.119-129
• /
• 2004

This paper is designed to report the results of development and validation procedures in relation to the Freeway Incident Management System (FIMS) prototype development as part of Intelligent Transportation Systems Research and Development program. The central core of the FIMS is an integration of the component parts and the modular, but the integrated system for freeway management. The whole approach has been component-orientated, with a secondary emphasis being placed on the traffic characteristics at the sites. The first action taken during the development process was the selection of the required data for each components within the existing infrastructure of Korean freeway system. After through review and analysis of vehicle detection data, the pilot site led to the utilization of different technologies in relation to the specific needs and character of the implementation. This meant that the existing system was tested in a different configuration at different sections of freeway, thereby increasing the validity and scope of the overall findings. The incident detection module has been performed according to predefined system validation specifications. The system validation specifications have identified two component data collection and analysis patterns which were outlined in the validation specifications; the on-line and off-line testing procedural frameworks. The off-line testing was achieved using asynchronous analysis, commonly in conjunction with simulation of device input data to take full advantage of the opportunity to test and calibrate the incident detection algorithms focused on APID, DES, DELOS and McMaster. The simulation was done with the use of synchronous analysis, thereby providing a means for testing the incident detection module.

• Asia pacific journal of information systems
• /
• v.22 no.4
• /
• pp.7-29
• /
• 2012

Smartphone and its applications (i.e. apps) are increasingly penetrating consumer markets. According to a recent report from Korea Communications Commission, nearly 50% of mobile subscribers in South Korea are smartphone users that accounts for over 25 million people. In particular, the importance of smartphone has risen as a geospatially-aware device that provides various location-based services (LBS) equipped with GPS capability. The popular LBS include map and navigation, traffic and transportation updates, shopping and coupon services, and location-sensitive social network services. Overall, the emerging location-based smartphone apps (LBA) offer significant value by providing greater connectivity, personalization, and information and entertainment in a location-specific context. Conversely, the rapid growth of LBA and their benefits have been accompanied by concerns over the collection and dissemination of individual users' personal information through ongoing tracking of their location, identity, preferences, and social behaviors. The majority of LBA users tend to agree and consent to the LBA provider's terms and privacy policy on use of location data to get the immediate services. This tendency further increases the potential risks of unprotected exposure of personal information and serious invasion and breaches of individual privacy. To address the complex issues surrounding LBA particularly from the user's behavioral perspective, this study applied the privacy calculus model (PCM) to explore the factors that influence the adoption of LBA. According to PCM, consumers are engaged in a dynamic adjustment process in which privacy risks are weighted against benefits of information disclosure. Consistent with the principal notion of PCM, we investigated how individual users make a risk-benefit assessment under which personalized service and locatability act as benefit-side factors and information privacy risks act as a risk-side factor accompanying LBA adoption. In addition, we consider the moderating role of trust on the service providers in the prohibiting effects of privacy risks on user intention to adopt LBA. Further we include perceived ease of use and usefulness as additional constructs to examine whether the technology acceptance model (TAM) can be applied in the context of LBA adoption. The research model with ten (10) hypotheses was tested using data gathered from 98 respondents through a quasi-experimental survey method. During the survey, each participant was asked to navigate the website where the experimental simulation of a LBA allows the participant to purchase time-and-location sensitive discounted tickets for nearby stores. Structural equations modeling using partial least square validated the instrument and the proposed model. The results showed that six (6) out of ten (10) hypotheses were supported. On the subject of the core PCM, H2 (locatability ${\rightarrow}$ intention to use LBA) and H3 (privacy risks ${\rightarrow}$ intention to use LBA) were supported, while H1 (personalization ${\rightarrow}$ intention to use LBA) was not supported. Further, we could not any interaction effects (personalization X privacy risks, H4 & locatability X privacy risks, H5) on the intention to use LBA. In terms of privacy risks and trust, as mentioned above we found the significant negative influence from privacy risks on intention to use (H3), but positive influence from trust, which supported H6 (trust ${\rightarrow}$ intention to use LBA). The moderating effect of trust on the negative relationship between privacy risks and intention to use LBA was tested and confirmed by supporting H7 (privacy risks X trust ${\rightarrow}$ intention to use LBA). The two hypotheses regarding to the TAM, including H8 (perceived ease of use ${\rightarrow}$ perceived usefulness) and H9 (perceived ease of use ${\rightarrow}$ intention to use LBA) were supported; however, H10 (perceived effectiveness ${\rightarrow}$ intention to use LBA) was not supported. Results of this study offer the following key findings and implications. First the application of PCM was found to be a good analysis framework in the context of LBA adoption. Many of the hypotheses in the model were confirmed and the high value of $R^2$ (i.,e., 51%) indicated a good fit of the model. In particular, locatability and privacy risks are found to be the appropriate PCM-based antecedent variables. Second, the existence of moderating effect of trust on service provider suggests that the same marginal change in the level of privacy risks may differentially influence the intention to use LBA. That is, while the privacy risks increasingly become important social issues and will negatively influence the intention to use LBA, it is critical for LBA providers to build consumer trust and confidence to successfully mitigate this negative impact. Lastly, we could not find sufficient evidence that the intention to use LBA is influenced by perceived usefulness, which has been very well supported in most previous TAM research. This may suggest that more future research should examine the validity of applying TAM and further extend or modify it in the context of LBA or other similar smartphone apps.

• Journal of Plant Biotechnology
• /
• v.43 no.3
• /
• pp.261-271
• /
• 2016

Citrus is an economically important fruit crop widely growing worldwide. However, citrus production largely depends on natural hybrid selection and bud sport mutation. Unique botanical features including long juvenility, polyembryony, and QTL that controls major agronomic traits can hinder the development of superior variety by conventional breeding. Diverse factors including drastic changes of citrus production environment due to global warming and changes in market trends require systematic molecular breeding program for early selection of elite candidates with target traits, sustainable production of high quality fruits, cultivar diversification, and cost-effective breeding. Since the construction of the first genetic linkage map using isozymes, citrus scientists have constructed linkage maps using various DNA-based markers and developed molecular markers related to biotic and abiotic stresses, polyembryony, fruit coloration, seedlessness, male sterility, acidless, morphology, fruit quality, seed number, yield, early fruit setting traits, and QTL mapping on genetic maps. Genes closely related to CTV resistance and flesh color have been cloned. SSR markers for identifying zygotic and nucellar individuals will contribute to cost-effective breeding. The two high quality citrus reference genomes recently released are being efficiently used for genomics-based molecular breeding such as construction of reference linkage/physical maps and comparative genome mapping. In the near future, the development of DNA molecular markers tightly linked to various agronomic traits and the cloning of useful and/or variant genes will be accelerated through comparative genome analysis using citrus core collection and genome-wide approaches such as genotyping-by-sequencing and genome wide association study.