• Journal of Korean Society of Forest Science
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• 제109권3호
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• pp.259-270
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• 2020

Extreme weather events, such as heat and drought, have occurred frequently over the past two decades. This has led to continuous reports of cases of forest damage due to physiological stress, not pest damage. In 2014, pine trees were collectively damaged in the forest genetic resources reserve of Sogwang-ri, Uljin, South Korea. An investigation was launched to determine the causes of the dieback, so that a forest management plan could be prepared to deal with the current dieback, and to prevent future damage. This study aimedto 1) understand the topographic and structural characteristics of the area which experienced pine tree dieback, 2) identify the main causes of the dieback, and 3) predict future risk areas through the use of machine-learning techniques. A model for identifying risk areas was developed using 14 explanatory variables, including location, elevation, slope, and age class. When three machine-learning techniques-Decision Tree, Random Forest (RF), and Support Vector Machine (SVM) were applied to the model, RF and SVM showed higher predictability scores, with accuracies over 93%. Our analysis of the variable set showed that the topographical areas most vulnerable to pine dieback were those with high altitudes, high daily solar radiation, and limited water availability. We also found that, when it came to forest stand characteristics, pine trees with high vertical stand densities (5-15 m high) and higher age classes experienced a higher risk of dieback. The RF and SVM models predicted that 9.5% or 115 ha of the Geumgang Pine Forest are at high risk for pine dieback. Our study suggests the need for further investigation into the vulnerable areas of the Geumgang Pine Forest, and also for climate change adaptive forest management steps to protect those areas which remain undamaged.

• Journal of Korean Society of Forest Science
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• 제87권4호
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• pp.549-556
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• 1998

To develop the effective methods of flowering stimulation, Hinoki cypress (Chamaecyparis obtusa Sieh. et Zuec.) grafts growing in a seed orchard and in a clone bank in Southern Breeding Station of Cheju were applied with gibberellin treatments, and predicted the seed production potential. In the seed orchard, $GA_{4/7}$ 1.5cc was injected into the stem of drafts and sprayed whale tree crown with $GA_3$ 300ppm and $GA_{4/7}$ 300ppm. Un the other hand, in the clonal archives, drafts were given intrusion of $GA_{4/7}$ 1.5cc into the excised and open inner part of bark wind $GA_3$ 20mg and sprayed with $GA_3$ 300ppm. Additionally, grafts growing in the seed orchard were treated with gibberellins at 3 different periods of time and 3 different treatments during the growing season. The results obtained here are summarized as follows : 1. All of the applications of Gilbberellin promoted female flower formation. Among these, the treatment of intrusion of $GA_{4/7}$ 1.5cc into the excised and open inner part of bark was racist effective, followed by the spraying of $GA_3$ 300ppm. Similarly, the applications of gibberellin promoted male flower formation. 2. Regarding the time of applications, treatment on August 15 was more effective than those of August 31 and September 11 in the stimulation of female flowers. On the contrary, there was no significant difference in the number of male flowers among 3 different time treatments. 3. It was supposed that the application of the intrusion of $GA_{4/7}$ 1.5cc into the excised and open inner part of bark on August 15 showing the best effect in female flower formation can produce 22.12kg seeds per ha. 4. Considerable significant difference existed among clones for both female and male flower formations. 5. Flower formation, especially female flower formation, seemed to be partially associated with the genetic potential of individual trees.

• Journal of Life Science
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• 제16권4호
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• pp.626-631
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• 2006

This study was carried out to investigate the physical characteristics (height, body lenght, chest depth, head type, ear type, body color, eye type and tail type) and genetic diversity using 15 microsatellite DNA markers (PEZ 1, 5, 8, 10, 11, 12, 13, 15, 16, 17, 20, 21, FHC 2010, FHC 2054 and FHC 2079) in 44 random Miryang native dogs(6 months${\sim}$12 years old). The height, body lenght, and chest depth of Miryang native dogs were 43-55 cm(mean 49.5 cm), 45-60 cm(mean 54.3 cm), and 50-64 cm(mean 57.9 cm), respectively. Miryang native dog was medium sized. The head and eye type were reverse-triangle(100%), triangle (90.9%) and newborn moon(9.1%), respectively. Most of body color had white coat color(93.2%), light pink tongue color(100%), light black anal color(90,9%) and pink claw color(100%). The ear type showed erect ear(100%), and half-curled(56.8%), upward(34.1%), curled(9.1%) in tail type, respectively. Number of alleles observed at a single locus ranged from 2 (PEZ 21 and FHC 2010) to 14 (PEZ 13), with average number of alleles per locus of 6.13. The expected heterozygosities of 15 microsatellite loci were estimated based on gene frequencies. The highest expected heterozygosity, 0.863 was estimated in PEZ 13 locus and the lowest, 0.455 in PEZ 21 and FHC 2010 locus. And the mean expected heterozygosity of 15 microsatellite markers was calculated as 0.635. Polymorphic information content (PIC) values were ranged from 0.348 (PEZ 21 and FHC 2010) to 0.837 (PEZ 13), and the mean PIC value was calculated as 0.570. Of the 15 markers, PEZ 10, PEZ 13, PEZ 17 and FHC 2054 loci have relatively high PIC value (> 0.7) in Miryang native dog. In order to determine the efficieney of parentage control, exclusion probabilities (PE) were calculated for each allele. The highest PE 1 and PE 2 in PEZ 13 locus was caculated to 0.548 and 0.710, respectively. And the total exclusion power in PE 1 and PE 2 was calculated to 0.9895 and 0.9996, respectively. These results can give basic information for perservation and research in Miryang native dog, and phylogenetic relationships of the Korean native dog and Asian dog breeds.

• Journal of Life Science
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• 제26권8호
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• pp.904-910
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• 2016

Complex traits are determined by the combined effects of many loci and are affected by gene networks or biological pathways. Systems biology approaches have an important role in the identification of candidate genes related to complex diseases or traits at the system level. The gene network analysis has been performed by diverse types of methods such as gene co-expression, gene regulatory relationships, protein-protein interaction (PPI) and genetic networks. Moreover, the network-based methods were described for predicting gene functions such as graph theoretic method, neighborhood counting based methods and weighted function. However, there are a limited number of researches in livestock. The present study systemically analyzed genes associated with 102 types of economic traits based on the Animal Trait Ontology (ATO) and identified their relationships based on the gene co-expression network and PPI network in cattle. Then, we constructed the two types of gene network databases and network visualization system (http://www.nabc.go.kr/cg). We used a gene co-expression network analysis from the bovine expression value of bovine genes to generate gene co-expression network. PPI network was constructed from Human protein reference database based on the orthologous relationship between human and cattle. Finally, candidate genes and their network relationships were identified in each trait. They were typologically centered with large degree and betweenness centrality (BC) value in the gene network. The ontle program was applied to generate the database and to visualize the gene network results. This information would serve as valuable resources for exploiting genomic functions that influence economically and agriculturally important traits in cattle.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제64권4호
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• pp.422-431
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• 2019

Severe droughts in spring have occurred frequently in Korea in recent years, exerting a critical impact on corn yield. Therefore, it is necessary to find physiological and/or molecular indicators of the response to drought stress in maize plants. In this study, we investigated the effects of water-deficit stress on two Korean elite F₁ maize hybrids, Ilmichal and Gwangpyeongok, by withholding water for 10 days at tassel initiation. The water deficit drastically reduced the relative leaf water content, leaf number, leaf area, and stem length, leading to dry matter reduction. Moreover, it reduced the SPAD values and stomatal conductance of leaves in drought-stressed plants of both hybrids. Importantly, the number of leaves and SPAD value were non-destructive and easy to investigate in response to water-deficit stress, suggesting that they may be useful indicators for screening drought-tolerant genetic resources. We detected more than 100 spots that were differentially accumulated under drought stress. Of these spots, a total of 21 protein spots (≥1.5-fold) from drought-exposed maize leaves were successfully analyzed by MALDI-TOF-TOF mass spectrometry. Functional annotation using Gene Ontology analysis revealed that most of the identified proteins were involved in carbohydrate metabolism, stress response fatty acid catabolism, photosynthesis, energy metabolism, and transport. The protein expression levels were increased in both Ilmichal and Gwangpyeongok, except for triosephosphate isomerase, fructose-bisphosphate aldolase, and an uncharacterized protein. The lactoylglutathione lyase delta (3,5)-delta (2,4)-dienoyl-CoA isomerase was overexpressed in Gwangpyeongok only. The results obtained from this study suggest that the drought-specific genes may be useful as molecular markers for screening drought-tolerant maize genotypes.

• Korean Journal of Organic Agriculture
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• 제16권3호
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• pp.309-320
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• 2008

This study was conducted to determine the effects of different types of hilly pasture grazing on growth and meat quality in organic Korean black goats, and to obtain basic data for the production of organic goats. A total of 40 goats with similar age and BW were equally allocated to four dietary treatments in a randomized complete block design. Dietary treatments included grazing types of four different hilly pastures; T1: forages types, T2: organic forages types, T3: native plants types, and T4: browse types, respectively. The trial lasted for 174 days from 15th of May to 5th of November, 2007 in Livestock Genetic Resources Experiment Station, National Institute of Animal Sciences. At the end of trial, all animals were slaughtered to analyze carcass characteristics and meat quality. Average daily gain was significantly (p<0.05) higher for T1 treatments than for others. Dressing percentage was significantly (p<0.05) higher for T1 and T2 than for T3 and T4 treatments. Meat percentage of T1 treatments was significantly (p<0.05) higher than those of other treatments. For meat properties, crude fat content was highest in T3 treatments. Linoleate (18:2n6) and linolenate (18:3n3) contents tended to be higher in T1 than those of other treatments, while arachidonate (20:4n6) content tended to be higher in T3 and T4 than that of other treatments. Shear force was lower (p<0.05) for T3 than other treatments. For sensory results, juiciness and tenderness tended to be greater (p<0.05) in T2 and T3, and flavour tended to be greater (p<0.05) in T3 and T4. The results indicated that grazing in hilly pastures for organic Korean black goats was somewhat less in their performances and carcass characteristics, but not behind in the meat quality and physical characteristics as compared with the conventional regimen. Therefore, it would be expected that goats grazing in hilly pastures made it possible to produce organic animal products with a high safety and also might lead to increase of breeders income and consumers satisfaction.

• Korean Journal of Breeding Science
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• 제41권4호
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• pp.412-419
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• 2009

In order to study the inheritance of watermelon seed size, we used six watermelon lines of different seed sizes as parental lines. Six lines include three accessions, 'PI525088' with giant seed (GS), 'Charleston Gray' with big seed (BS), and 'NT' with normal medium size seed (NS), and three near isogenic lines, 'NTss' with small seed (SS), 'NTms' with micro seed (MS) and 'NTts' with tomato seed size (TS) bred by crosses between accession 'NT' of normal seed size and accession 'TDR' of the smallest seed size,. We inspected $F_1$, $F_2$, $BC_1F_1$ (P1), $BC_1F_1$ (P2) populations from the crosses between the adjacent seed size materials like $GS{\times}BS$, $BS{\times}NS$, $NS{\times}SS$, and $MS{\times}TS$, and two crosses between parental lines showing relatively big difference in seed size such as $GS{\times}TS$ and $NS{\times}TS$. Partial single dominant inheritance patterns were observed between $GS{\times}BS$, $NS{\times}SS$, and $MS{\times}TS$ and inheritance patterns based on two genes or more than two genes were speculated between $BS{\times}NS$. A very wide segregation range was observed from the population of $GS{\times}TS$ indicating many quantitative genes involved in the seed sizes. Overall, we speculated that more than six genes are involved in between the biggest and smallest seed size watermelon and three major genes between the normal seed size and the smallest seed size watermelon.

• Korean Journal of Breeding Science
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• 제43권5호
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• pp.413-421
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• 2011

The main objective of this study was to develop the multi-resistance lines to insects(brown planthopper; BPH, rice green leafhopper; GRH) and disease(blast; BL, bacterial blight; BB and rice stripe virus disease;RSV) with good grain quality and plant type by combining conventional breeding and marker assisted selection(MAS) and to eliminate the linkage drag effects between Bph1 gene and culm length, we conducted MAS of Bph1 gene in advanced backcross and double cross progenies. 'Nampyeong', 'Junam' and 'Milyang220' were used as the parent in this study. 'Milyang220' was used as the donor of brown planthopper resistance gene Bph1 with tall culm length. Two backcross progenies were developed using two recipients 'Nampyeong' carrying GRH resistance gene Grh3(t) with good grain appearance and 'Junam' harboring bacterial blight resistance gene Xa3 with short culm length. Two $BC_1$ generations were resulted from the backcrossing of the $F_1$ plants with recurrent parents 'Nampyeong' and 'Junam'. The second rounds of backcrossing($BC_2$) were derived from the cross of selected resistant $BC_1F_1$ plants based on heterozygous genotype of RM28493 linked to Bph1 gene. The double crossed population was constructed from the cross of between each heterozygous $BC_2F_1$ plants at RM28493 locus of '$Nampyeong^*3$ / Milyang220' and '$Junam^*3$ / Milyang220'., The homozygous alleles in Bph1 gene were selected using co-dominant DNA marker RM28493 in double crossed population. Eighty-five lines with multi-resistance to BL, BB, RSV, GRH and BPH were selected by bio-assay and MAS in generation of double crossing. The culm length, head rice ratio and yield of the selected multi resistance lines was ranged from 71 to 88 cm, from 51 to 93%, from 449 to 629 kg/10a. respectively. We can select a promising multi resistance line similar with 'Nampyeong' of major agronomic traits such as culm legnth, head rice ratio and yield. It was designated as Milyang265. Finally this study was developed the multi resistant varieties against to insects and diseases with the good grain quality 'Milyang265' by the advanced backcross and double cross combining MAS and it can be used as genetic resources of multi-resistance to insect and diseases in rice breeding programs.

• Journal of Plant Biotechnology
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• 제45권4호
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• pp.400-408
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• 2018

Biodiversity has continued to degrade in the $21^{st}$ century due to global warming occasioned by destruction of the environment around the world.. The Nagoya protocol places Korea in a unique position to effectively develop and protect its domestic genetic resources. Microalgae under study in this research contains large amount of antioxidant substances such as beta carotene and astaxanthin, that can be used as biological resource owing to the large amounts of biomass that can be secured through photosynthesis. However, it is difficult to preserve it since cryopreservation method used for long-term preservation is yet to be developed. A basic study for long term cryopreservation was carried out on Nizschia frustulum and Nitzschia amabilis which belong to marine diatoms. As cryoprotectants (CPAs), glycerol, DMSO, and methanol which penetrate into cells were prepared at 5%, 10%, and 15% concentrations each, in case of methanol, it was tested at concentrations of 5%, 10% and 12% by its nature. Two kinds of microalgae, N. frustulum and N. amabilis, were diluted with $10^2$, $10^3$ and $10^4cells\;ml^{-1}$, respectively. The highest survival rate was shown at12% concentration of methanol, and the figures were $6.94{\pm}0.31%$ in N. frustulum and $8.85{\pm}0.16%$ in N. amabilis. As a result of 3 weeks cultivation of thawed microalgae after freezing, the result is shows that N. frustulum increased about 10 times faster and N. amabilis increased about 12 times the original concentration.

• Korean Journal of Breeding Science
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• 제50권4호
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• pp.453-462
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• 2018

This study was carried out to investigate the utilization value of legume crops collected in tropical and subtropical areas. We examined agronomic traits to assess domestic adaptability and evaluated useful components of foreign legumes. We used a total of 201 genetic resources of three legumes, consisting of 68 lentils, 72 chickpeas and 61 guars. The average number of days to flowering of the three legumes ranged from 56.7 to 60.8 days; the shortest in guar and longest in chickpea. The average number of days to growth of the three legumes ranged from the shortest 86.8 days in lentil, to the longest 163.9 days in guar. The maturation period of the three legumes lasted from the end of May until mid-September, based on sowing in March. However, the average yield of lentil was very low, ranging from 0.5 g to 30.6 g, with an average 16.4 g based on 10 plants per accession. The average 100 seed weight of the three legumes was 2.2 g for lentil, 22.9 g for chickpea, and 3.8 g for guar. The crude protein content ranged from 14.1% to 32.4% with an average of 20.4%, the highest for guar and the lowest for chickpea. The average crude oil content in the three legume crops was generally low, ranging from 0.8% in lentil, to 4.3% in chickpea. The average dietary fiber content in the three legume crops varied from 15.7% to 50.7%. Guar was the highest source of fiber, followed by chickpea (19.3%) and lentil (15.7%). From the agricultural traits analysis, chickpea and guar could grow domestically. However, lentil was difficult to flower and fruit normally during the warmer season after May. Therefore, lentil should be considered for late summer cropping during the cool season. The physicochemical properties of the three legumes seem to be useful as they are similar to, or better than, those of the control common bean.