• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.248-253
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• 2018

Freshwater farms are primarily located adjacent to rivers and lakes, facilitating the introduction and spread of pathogens into natural systems. Therefore, it is necessary to continuously monitor natural aquatic organisms, the breeding environment, and infection rates by pathogenic organisms. Fish and crustaceans were sampled 4 times in the Geum River estuary in 2016. The samples were analyzed for the presence of pathogens for reportable communicable diseases, including KHVD (koi herpesvirus disease), SVC (spring viraemia of carp), EUS (epizootic ulcerative syndrome) and WSD (white spot disease); parasite abundance was also examined. The dominant fish species were deep body bitterling Acanthorhodes macropterus (21.4%), followed by skygager Erythroculter erythropterus (12.7%). For crustaceans, Palaemon paucidens and Chinese mitten crab Eriocheir sinensis were dominant. Sixty fish and 36 crustacean species were examined for reportable communicable diseases. When using a specific primer set for each disease, PCR analysis did not detect any reportable communicable diseases in the samples. Some instances of Dactylogyrus, copepods, nematodes and metacercaria were detected. However, the PCR results indicated that the metacercaria were not Clonorchis sinensis.

• Research in Plant Disease
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• v.19 no.1
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• pp.31-35
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• 2013

Thirteen soybean cyst nematode (SCN) (Heterodera glycines) populations collected in Korea were examined in their HG type by their reproductivity on 7 Plant Introduction indicators for the identification of HG type. Six HG types were identified, HG type 0, 2, 5, 2.5, 1.2.7, and 2.5.7. HG type 2.5 was the most frequent (4 samples, 30.8%), followed by HG type 2.5.7 (3 samples, 23.0%). About 76.9% of SCN populations were reproduced on PI 88788, followed by PI 209332 (61.5%), PI 548316 ('Cloud') (30.8%), and PI 548402 ('Peking') (7.7%). No population could reproduce on PI 90763, PI 437654, thus, they could be used for resistant source for developing SCN resistant soybean in Korea.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.139-145
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• 2001

Peony has been cultivated as medicinal plant in East and also its beautiful flower was acknowledged over the world. In West, numerous peony varieties were developed for ornamental use but not in the country. Ninety two varieties of ornamental peony were introduced from U.S.A. and investigated in Uisong Medicinal Plant Experiment Station during $1997{\sim}1999$. For most of them, their growth habit were good in the country. Their flower colors were clearer and stems were thicker and stronger than domestic peonies. Some of them showed vigorous growth and made very high yield of root. Most of varieties showed proper content of paeoniflorin, medicinal component of peony, for medicinal use.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.35.1-35.13
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• 2021

Background: African swine fever (ASF) is an infectious viral disease of domestic pigs that presents as a hemorrhagic fever, and for which no effective vaccine is available. The disease has a serious negative social and economic impact on pig keepers. There is limited information on the potential risk factors responsible for the spread of ASF in South Kivu. Objective: The aim of this study was to determine the potential risk factors associated with ASF infection in suspected ASF virus (ASFV)-infected pigs. Methods: We sampled whole blood from 391 pigs. Additionally, 300 pig farmers were interviewed using a structured questionnaire. Viral DNA was detected by using the real-time polymerase chain reaction technique. Results: The majority of pigs sampled, 78% (95% confidence interval [CI], 74.4-82.6), were of local breeds. Over half, 60.4% (95% CI, 55.5-65.2), were female, and most of them, 90.5% (95% CI, 87.6-93.4), were adult pigs (> 1 year old). Viral DNA was detected in 72 of the 391 sampled pigs, indicating an overall infection rate of 18.4% (95% CI, 14.5-22.4). Multivariable logistic regression analysis revealed several risk factors positively associated with ASFV infection: feeding with swill in pen (odds ratio [OR], 3.8; 95% CI, 2.12-6.77); mixed ages of pigs in the same pen (OR, 3.3; 95% CI, 1.99-5.57); introduction of new animals to the farm (OR, 5.4; 95% CI, 1.91-15.28). The risk factors that were negatively (protective) correlated with ASFV positivity were the presence of male animals and the use of an in-pen breeding system. Conclusion: Local pig farmers should be encouraged to adopt proper husbandry and feeding practices in order to increase the number of ASF-free farms.

• Animal Bioscience
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• v.34 no.6
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• pp.941-948
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• 2021

Objective: In Japan, approximately 50 breeds of indigenous domestic chicken, called Japanese native chickens (JNCs), have been developed. JNCs gradually became established based on three major original groups, "Jidori", "Shoukoku", and "Shamo". Tosa-Jidori is a breed of Jidori, and archival records as well as its morphologically primitive characters suggest an ancient origin. Although Jidori is thought to have been introduced from East Asia, a previous study based on mitochondrial D-loop sequences demonstrated that Tosa-Jidori belongs to haplogroup D, which is abundant in Southeast Asia but rare in other regions, and a Southeast Asian origin for Tosa-Jidori was therefore suggested. The relatively small size of the D-loop region offers limited resolution in comparison with mitogenome phylogeny. This study was conducted to determine the phylogenetic position of the Tosa-Jidori breed based on complete mitochondrial D-loop and mitogenome sequences, and to clarify its evolutionary relationships, possible maternal origin and routes of introduction into Japan. Methods: Maximum likelihood and parsimony trees were based on 133 chickens and consisted of 86 mitogenome sequences as well as 47 D-loop sequences. Results: This is the first report of the complete mitogenome not only for the Tosa-Jidori breed, but also for a member of one of the three major original groups of JNCs. Our phylogenetic analysis based on D-loop and mitogenome sequences suggests that Tosa-Jidori individuals characterized in this study belong to the haplogroup D as well as the sub-haplogroup E1. Conclusion: The sub-haplogroup E1 is relatively common in East Asia, and so although the Southeast Asian origin hypothesis cannot be rejected, East Asia is another possible origin of Tosa-Jidori. This study highlights the complicated origin and breeding history of Tosa-Jidori and other JNC breeds.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.26-35
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• 2013

This study was conducted to select superior provenances of Scots pine (Pinus sylvestris L.) well adapted to Korean environment for timber production. In 1976, twenty-two provenances of Scots pine were introduced from Sweden and the seeds were sown in seed beds in March. After one year, the seedlings were transplanted to nursery beds. The resulting 1-1 seedlings of 22 provenances were planted at Whaseong in 1978. Randomized complete block design with 3 replications were used for test plantation. Each provenance was planted with 20-tree row plot in each block and at a spacing of $1.8{\times}1.8m$. The growth performance of each provenance was monitored up to 33-years after planting. There were significant differences among provenances in volume growth. F3001 provenance showed the best volume growth of 33-years after planting ($0.160m^3$), which was 2.2 times greater than that of the lowest provenance W2027 ($0.072m^3$). The ranking of provenances was stabilized after 14 years. Comparing to reference tree species, Japanese red pine (Pinus densiflora), all Scots pine provenances showed poor growth performance. In other words, volume growth of Japanese red pine at age 28 and 33 were 2.1 and 3.3 times greater than that of Scots pine, respectively. Moreover, survival rate of Scots pine was lower than that of Japanese red pine. Based on these results, it was suggested that Scots pine was not suitable to Korean environments. The cause of maladaptation of Scots pine and the implications of introduction breeding were discussed.

• Proceedings of the Korean Society of Tobacco Science Conference
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• 1997.10a
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• pp.134-152
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• 1997

Plant viruses of tobacco including tobacco mosaic virus (TMV) and potato virus Y (PVY) cause severe economic losses in leaf-tobacco production. Cultural practices do not provide sufficient control against the viruses. Use of valuable resistant cultivars is most recommendable for the control of the viruses. However, conventional breeding programs are not always proper for the development of virus-resistant plants mostly owing to the frequent lack of genetic sources and introduction of their unwanted properties. Therefore, we tried to develop virus-resistant tobacco plants by transforming commercial tobacco cultivars, NC 82 and Burley 21, with coat protein (CP) or replicase (Nlb) genes of TMV and PVY necrosis strain (PVY-VN) with or without untranslated region (UTR) and with or without mutation. Each cDNA was cloned and inserted in plant expression vectors with 1 or 2 CaMV 35S promotors, and introduced into tobacco leaf tissues by Agrobacterium tumefaciens LBA 4404. Plants were regenerated in kanamycin-containing MS media. Regenerated plants were tested for resistance to TMV and PVY In these studies, we could obtain a TMV-resistant transgenic line transformed with TMV CP and 6 genetic lines with PVY-VN cDNAs out of 8 CP and replicase genes. In this presentation, resistance rates, verification of gene introduction in resistant plants, stability of resistance through generations, characteristics of viral multiplication and translocation in resistant plants, and resistance responses relative to inoculum potential and to various PVY strains will be shown. Yield and quality of leaf tobacco of a promising resistant tobacco line will be presented.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.187-194
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• 2010

The soybean stay green mutant genotype (SSG) derived from the nuclear gene, d1d2, and cytoplasmic gene, cytG, inhibit the breakdown of chloroplast in the leaves, pod walls, seed coats, and embryos during maturity. Soybean seed with black seed coat and green cotyledon (SBG) are preferred than black seed coat with yellow cotyledon (SBY) especially for cooking with rice and as source of traditional food in Korea. The researchers evaluated the seed's chlorophyll content of SSG and introduced SSG to the SBG variety breeding program. The seed chlorophyll content of SSG with d1d2 was $39.93{\sim}60.80\;{\mu}g/g$ and SSG with cytG $38.08{\sim}39.89\;{\mu}g/g$. The Korean SBG variety which was derived from SSG with cytG, contains $16.35{\sim}37.73\;{\mu}g/g$. The composition of seed chlorophyll differs according to the genetic background of SSG genotype. Inheritance study showed that cotyledon color was segregated 15:1 (yellow:green) at $F_2$ seed indicating two recessive genes control green cotyledon as revealed by previous study. Only less than 3% soybean lines showed black seed coat with green cotyledon among crosses SBY and SSG (d1d2). Results showed that SSG with d1d2 can be used as a good source for SBG with high chlorophyll content in the seed cotyledon, but due to the complex genetic behavior, breeding resource of SBG with d1d2 should be prepared to improve the breeding efficiency for development SBG variety.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.519-542
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• 2019

Twenty soybean cultivars developed recently were assessed using 27 insertion and deletion (InDel) markers derived from dense variation blocks (dVBs) of soybean genome. The objective of this study is to identify the distinctness and genetic relationships among a total of 169 soybean accessions including new cultivars. The genetic homology between 149 accessions in the soybean barcode system and 20 new cultivars was 61.3% on average with the range from 25.9% to 96.3%, demonstrating the versatile application of these markers for cultivars identification. The phylogenic analysis revealed four subgroups related to their usage. The 80% of cultivars for vegetable and early maturity and the 65.9% of cultivars for bean sprouts were clustered in subgroup I-2 and II-2, respectively, indicating of the limited gene pools of their crossing parents in breeding. On the other hands, the cultivars for soy sauce and tofu with considerable gene flow by genome reshuffling were distributed evenly to several subgroups, I-1 (44.4%), I-2 (26.4%) and II-2 (23.6%). We believe that the 27 InDel markers specific to dVBs can be used not only for cultivar identification and genetic diversity, but also in breeding purposes such as introduction of genetic resources and selection of breeding lines with target traits.

• Journal of Korean Society of Forest Science
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• v.14 no.1
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• pp.1-20
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• 1972

The trend and achievements of forest genetics research in abroad were investigated through observation tours and reference work and following facts were found to be important aspects which should be adopted in the forest genetics research program in Korea. Because of world wide recognization on the urgency of taking a measure to reserve some areas of the representative forest type on the globe before the extingtion of such forest type as the results of continuous exploitations of the natural forests to meet the timber demand all over the world, it is urgently needed to take a measure to reserve certain areas of natural stand of Pinus koraiensis, Pinus parviflora, Pinus densiflora f. erectra, Abies koreana, Quercus sp., Populus sp., etc. as gene pool to be used for the future program of forest tree improvement. And the genetic studies of those natural forest of economic tree species are also to be performed. 1. Increase of the number of selected tree for breeding purpose. Because of the fact that the number of plus tree at present is too small to carry out selection program for tree improvement, particularly for the formation of source population for recurrent selection of parent trees of the 2nd generation seed orchard it is to be strongly emphasized to increase the number of plus tree by alleviating selection criteria in order to enlarge the population size of plus trees to make the selection program more efficient. 2. Progeny testing More stress should be placed on carrying out progeny testing of selected trees with open pollinated seeds. And particular efforts are to be made for conducting studies on adult/juvenile correlation of important traits with a view to enable to predict adult performances with some traits revealed in juvenile age thus to save time for progeny testing. 3. Genotype-environment interaction Studies on genotype and environment interaction should be conducted in order to elucidate whether the plus trees selected on the good site express their superiority on the poor site or not and how the environment affect the genotype. And the justification of present classification of seed distribution area should be examined. 4. Seed orchard of broad leaf tree species. Due to the difficulty of accurate comparison of growth rate of neighbouring trees of broad leaf tree species in natural stand, it is recommended that for the improvement of broad leaf trees a seedling seed orchard is to be made by roguing the progeny test plantation planted densely with control pollinated seedlings of selected trees. 5. Breeding for insect resistant varieties. In the light of the fact that the resistant characteristics against insect such as pine gall midge (Thiecodiplosis japonensis U. et I.) and pine bark beetle (Myelophilus pinipera L.) are highly correlated with the amount and quality of resin which are known as gene controlled characteristics, breeding for insect resistance should be carried out. 6. Breeding for timber properties. With the tree species for pulp wood in particular, emphasis should be placed upon breeding for high specific gravity of timber. 7. Introduction of Cryptomeria and Japanese Cypress In the light of the fact that the major clones of Cryptomeria are originated from Yoshino source and are being planted up to considerably north and high elevation in Japan, those species should be examined on their cold resistance in Korea by planting them in further northern part of the country.