• Journal of Sericultural and Entomological Science
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• v.24 no.1
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• pp.28-31
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• 1982

Flacherie virus (FV) is an important pathogen in the silkworm, which often gives serious damage to farmers for cocoon production. The inbred parents and F$_1$'s from an eight-parent diallel were examined to determine the inheritance of resistance to flacherie virus in the silkworm. Three resistant (R), two intermediate (M) and three susceptible (S) inbreds were used in the diallel with no reciprocals. Mean resistance was measured by survival rates of larvae which were fed on mulberry leaves sprayed with diluted mid-gut homogenate of FV infected larvae. Broad-sense heritability was obtained according to inbreds and F$_1$ family performance. Estimation of general (GCA) and specific combining ability (SCA) was made according to Griffing's Model 1, Method 2. Mean FV resistance of F$_1$ family displayed additive effect of the major gene, while heterotic effect was not significant. Considerable variation in FV resistance within F$_1$ groups of R$\times$S and S$\times$S indicated that action of minor genes for FV resistance may have been involved. FV resistance of inbreds perse and predominant effect of the major gene over minor gene(s) satisfactorily predicted the FV resistance of the hybrids. Broadsense heritability value of FV resistance on the basis of F$_1$ family performance averaged 93%, which suggested that environmental effects might have not been important in this experiment. GCA was highly significant for FV resistant among inbreds. GCA effect of 13.1 in Jam 108 was highest and -17.7 in Gyeongchu lowest. Effective selection for high FV resistance would be possible, using inbreds with high GCA effect and low GCA variance. SCA was significant among hybrids. High SCA effect in the hybrid of Geumho$\times$Mudeung (13.7) and Hansaeng #4$\times$Jam 115 (11.6) indicated that the interaction effect of minor genes for resistance to FV in the silkworm could be exploited by standard silkworm breeding procedures.

• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.357-366
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• 2010

The emergence of next-generation sequencing technologies has lead to application of new computational and statistical methodologies that allow incorporating genetic information from entire genomes of many individuals composing the population. For example, using single-nucleotide polymorphisms (SNP) obtained from whole genome amplification platforms such as the Ilummina BovineSNP50 chip, many researchers are actively engaged in the genetic evaluation of cattle livestock using whole genome relationship analyses. In this study, we estimated the genomic relationship matrix (GRM) and compared it with one computed using a pedigree relationship matrix (PRM) using a population of Hanwoo. This project is a preliminary study that will eventually include future work on genomic selection and prediction. Data used in this study were obtained from 187 blood samples consisting of the progeny of 20 young bulls collected after parentage testing from the Hanwoo improvement center, National Agriculture Cooperative Federation as well as 103 blood samples from the progeny of 12 proven bulls collected from farms around the Kyong-buk area in South Korea. The data set was divided into two cases for analysis. In the first case missing genotypes were included. In the second case missing genotypes were excluded. The effect of missing genotypes on the accuracy of genomic relationship estimation was investigated. Estimation of relationships using genomic information was also carried out chromosome by chromosome for whole genomic SNP markers based on the regression method using allele frequencies across loci. The average correlation coefficient and standard deviation between relationships using pedigree information and chromosomal genomic information using data which was verified using a parentage test andeliminated missing genotypes was $0.81{\pm}0.04$ and their correlation coefficient when using whole genomic information was 0.98, which was higher. Variation in relationships between non-inbred half sibs was $0.22{\pm}0.17$ on chromosomal and $0.22{\pm}0.04$ on whole genomic SNP markers. The variations were larger and unusual values were observed when non-parentage test data were included. So, relationship matrix by genomic information can be useful for genetic evaluation of animal breeding.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.428-435
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• 2003

This research was performed to examine an anti-inflammatory effects of Gamisangryosamul-Tang(GSS) and anti-pruritus effects of Ziyang-Go(Salve). This study was processed by three experiments; Experiment 1: Inhibitory activity of GSS extract on the degranulation of mast cell and histamine release in plasma induced by compound 48/80 i.p, injection after the pretreatment of GSS extract i.p, injection in Sprague-Dawley rats, Experiment 2: Anti-inflammatory effect of GSS extract on macropharge raw 264,7 cells treated by LPS 250 ppm (before 2 hours). Experiment 3: Measurement of passive cutaneous anaphylaxis and atopic dermatitis using NC/Nga mice, GSS extract inhibited histamine release by 70% compared to compound 48/80 treated control group and histologically significantly reduced (P<0,01) the degranulation of mast cell in SD rats. In GSS extract treated group, the expression of TNF-α in macropharge cell showed the remarkable inhibitory effect about 62% (P<0,01) compared to LPS treated control group. The expression of IL-6 appeared more effective by 46% than the LPS treated control group and by 6% compared to hydrocortison treated group, Comparing with steroid (0.05% prednisolon) ointment, Ziyan-Go treated group showed the significant(30%) recovery on skin response index in atopic dermatis like anaphylaxis mice(NC/Nga), Finally, in scratching behavioral tests of NC/Nga mice for three weeks, Ziyang-Go treated group significantly (P<0.05) suppressed the pruritus on the face, neck, ears and dorsal skin than inbred NC/Nga mice. However, the change of IgE and IFN-γ from the spleen cell of NC/Nga mice was not significantly different between the oral intake of GSS extract group and of saline intaked control group. Summary and Conclusion: This study demons trates that Ziyang-go have the equal anti-pruritus effect to steroid ointment and GSS extract have the notable immunologic activity on inflammatory in vivo and in vitro model. Advanced experiment of this study will be required for more reliable information about the correlation between the lymphokine (i.e. IgE) and the anti-allergic effects of GSS.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.12-20
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• 2016

Advances in DNA sequencing technologies have contributed to revolutionary understanding of many fundamental biological processes. With unprecedented cost-effective and high-throughput sequencing, a single laboratory can afford to de novo sequence the whole genome for species of interest. In addition, population genetic studies have been remarkably accelerated by numerous molecular markers identified from unbiased genome-wide sequences of population samples. As sequencing technologies have evolved very rapidly, acquiring appropriate individual plants or populations is a major bottleneck in plant research considering the complex nature of plant genome, such as heterozygosity, repetitiveness, and polyploidy. This challenge could be overcome by the old but effective method known as haploid induction. Haploid plants containing half of their sporophytic chromosomes can be rapidly generated mainly by culturing gametophytic cells such as ovules or pollens. Subsequent chromosome doubling in haploid plants can generate stable doubled haploid (DH) with perfect homozygosity. Here, classical methodology to generate and identify haploid plants or DH are summarized. In addition, haploid induction by epigenetic regulation of centromeric histone is explained. Furthermore, the utilization of haploid plant in the genomics era is discussed in the aspect of genome sequencing project and population genetic studies.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.117-122
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• 2003

Six isolates of Turnip mosaic Potyvirus (TuMV) namely, TuMV-CA7 from oriental cabbage, TuMV-TU and TuMV-TU2 from turnip, TuMV-RA from rape, TUMV-ST from stock, and TuMV-R9 from radish, and Ribgrass mosaic Tobamovirus (RMV-FG22) from oriental cabbage were isolated. Three kinds of characteristics of the six TuMV isolates were sorted by bioassay: TuMV-CA7 and TuMV-TU isolates infected mostly oriental cabbages; TuMV-ST, TuMV-TU2, and TuMV-R9 infected radishes; and TuMV-RA infected both oriental cabbages and radishes. Mixed infections of crucifers were RMV-FG22+TuMV-CA7, RMV-FG22+TuMV-TU, RMV-FG22+TuMV-RA, RMV-FG22+TuMV-ST, RMV-FG22 +TuMV-TU2 and RMV-FG22+TuMV-R9. Crops used were 'Tambok' cultivar resistant to TuMV, 'SSD63' susceptible inbred line of oriental cabbage, pure line of leaf mustard and 'Daeburyungyeorum' cultivar of radish. New specific ultrastructures of nonagon-like ring (NLR) and spiral aggregates (SA) by mixed infection with TuMV and RMV were formed in cells of crucifer plants. The NLR was made by a TuMV surrounded loosely by nine RMV particles, and the SA was formed spirally by full mixed of two virus particles. The SA had some NLR in its center, which was observed from cross sectioned SA. Host plants with specific ultrastructures expressed synergistic symptoms. Specific ultrastructures of NLR and SA were formed in combinations of RMV-FG22 and in TuMV-CA7, TuMV-TU, or TuMV-RA that could infect oriental cabbages. How-ever, no specific ultrastructures and mixing of the two virions in the same cell were observed in combinations of RMV-FG22, and TuMV-57, TuMV-TU2, or TuMV-R9 isolates haying virulence in radishes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.1
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• pp.1-5
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• 2013

Andaok, a new single cross variety, is a yellow dent maize hybrid (Zea mays L.) developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2011. This hybrid, which has a high yield of grain, was produced by crossing two inbred lines, KS161 and KS162. KS161 is the seed parent and KS162 is the pollen parent of Andaok. Silking date of Andaok is 3 days later than that of the check hybrid, Jangdaok. Plant height of Andaok is longer than that of Jangdaok. Ear numbers per 100 plants of Andaok is more than that of Jangdaok. Ear length of Andaok is shorter than that of Jangdaok. The weight of 100 seeds of Andaok is heavier than that of Jangdaok. It has moderate resistance to southern corn leaf blight (Bipolaris maydis), black streaked dwarf virus (BSDV) and corn borer. It has strong resistance to northern corn leaf blight (Exserohilum turcicum). It has resistance to lodging. Andaok was evaluated for its yield of grain at three locations from 2009 to 2011. The grain yield of Andaok was 7.80 ton/ha. Seed production of Andaok has gone well due to a good match during crossing between the seed parent, KS161, and the pollen parent, KS162, in Yeongwol.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.845-852
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• 2014

Among various abiotic stress factors, soil salinity decreases the photosynthetic rate, growth, and yield of plants. Recently, many genes have been reported to enhance salt tolerance. The objective of this study was to characterize the Brassica rapa Salt Stress Resistance (BrSSR) gene, of which the function was unclear, although the full-length sequence was known. To characterize the role of BrSSR, a B. rapa Chinese cabbage inbred line ('CT001') was transformed with pSL94 vector containing the full length BrSSR cDNA. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that the expression of BrSSR in the transgenic line was 2.59-fold higher than that in the wild type. Analysis of phenotypic characteristics showed that plants overexpressing BrSSR were resistant to salinity stress and showed normal growth. Microarray analysis of BrSSR over-expressing plants confirmed that BrSSR was strongly associated with ERD15 (AT2G41430), a gene encoding a protein containing a PAM2 motif (AT4G14270), and GABA-T (AT3G22200), all of which have been associated with salt tolerance, in the co-expression network of genes related to salt stress. The results of this study indicate that BrSSR plays an important role in plant growth and tolerance to salinity.

• Molecules and Cells
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• v.25 no.4
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• pp.467-478
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• 2008

Simple sequence repeats (SSRs) and interSSR (ISSR) marker systems were used in this study to reveal genetic changes induced by artificial selection for short/long larval duration in the tropical strain Nistari of the silkworm Bombyx mori. Artificial selection separated longer larval duration (LLD) ($29.428{\pm}0.723days$) and shorter larval duration (SLD) ($22.573{\pm}0.839days$) lines from a base, inbred population of Nistari (larval span of $23.143{\pm}0.35days$). SSR polymorphism was observed between the LLD and SLD lines at one microsatellite locus, Bmsat106 ($CA_7$) and at two loci of 1074 bp and 823 bp generated with the ISSR primer UBC873. Each of these loci was present only in the LLD line. The loci segregated in the third generation of selection and were fixed in opposite directions. In the $F_2$ generation of the $LLD{\times}SLD$ lines, the alleles of Bmsat106 and $UBC873_{1074bp}$ segregated in a 1:1 ratio and the loci were present only in the LLD individuals. $UBC873_{823bp}$ was homozygous. Single factor ANOVA showed a significant association between the segregating loci and longer larval duration. Together, the two alleles contributed to an 18% increase in larval duration. The nucleotide sequences of the $UBC873_{1074bp}$ and $UBC873_{823bp}$ loci had 67% A/T content and consisted of direct, reverse, complementary and palindromic repeats. The repeats appeared to be "nested" (59%) in larger repeats or as clustered elements adjacent to other repeats. Of 203 microsatellites identified, dinucleotides (67.8%) predominated and were rich in A/T and T/A motifs. The sequences of the $UBC873_{1074bp}$ and $UBC873_{823bp}$ loci showed similarity (E = 0.0) to contigs located in Scaffold 010774 and Scaffold 000139, respectively, of the B. mori genome. BLASTN analysis of the $UBC873_{1074bp}$ sequence showed significant homology of (nt.) 45-122 with upstream region of three exons from Bombyx. The complete sequence of this locus showed ~49% nucleotide conservation with transposon 412 of Drosophila melanogaster and the Ikirara insertions of Anopheles gambiae. The A + T richness and lack of coding potential of these small loci, and their absence in the SLD line, reflect the active process of genetic change associated with the switch to short larval duration as an adaptation to the tropics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.464-469
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• 2015

This study was carried out to find relationships of genetic distance and heterosis expression degree in the developed CNU waxy corn lines. The used material were developed in Corn Breeding Laboratory, Coll. of Agri. & Life Sci., CNU. Total 10 primers used for SSR maker analysis. In genetic distance, the used lines divided into four groups; A group has two lines, B group has one line, C group has ten lines and D group has eleven lines, respectively. Among used lines, CNU427 and CNU588 were very closed as a 74, while CNU451 and CNU429 were remote as a 40 inbred coefficient, respectively. While heterosis degree were very variable not only hybrids but also cross parents. Average heterosis of most cross-parent was high in plant height, ear height, flowering day and ear length. Especially, CNU H09-23 hybrid was high as 79.4% than other hybrids. Here, we gained the fact has closely relationship between genetic distance and heterosis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.81-85
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• 1989

One of the most important cultural techniques of pearl millet (Pennisetum americanum (L.) Leeke) is to encourage rapid and uniform emergence of seedlings to establish good stand and to let them grow well. Thus the objectives of the study were to investigate the effects of pre-sowing seed soaking and planting depth on dormancy breaking, germination and emergence of the seedlings, and to estimate the optimum planting season of pearl millet in Suwon, Korea. The seeds with dormancy germinated 99 to 100 percent when soaked in the H$_2$O$_2$ 1％ solution for 24 hours and rinsed with pure water, but germinated only 38％ and 83％ when soaked in pure water for 24 hours just after harvest and drying, and one month later from the harvest time, respectively. The seeds of Australia inbred line did not germinate at the constant 10$^{\circ}C$, but germinated at the constant 11$^{\circ}C$. It also was possible to estimate the optimum planting season by applying minimum temperature 11$^{\circ}C$ for germination. The minimum air temperature reached from late April in Suwon, Korea in regular years but fluctuated from late April to early May in 1986 and 1987. Thus, the safe planting season was mid-May for rapid and uniform germination of pearl millet seed. The optimum depth of planting was 2∼4cm under the optimum soil moisture condition, and 4 to 6 cm under the drier soil moisture condition. Subcoleoptile internode(mesocotyle) length increased according to increased depth of planting. Seedling crown placement also became deeper due to deeper planting of the seeds. The subcoleoptile internode length and seedling crown depth were positively correlated with actual planting depth, indicating that deeper planting would be not good for appropriate adventitious root and tiller development.