• Proceedings of the Korean Society of Crop Science Conference
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• 한국작물학회 2022년도 추계학술대회
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• pp.201-201
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• 2022

Rice bakanae disease is a serious global threat in major rice-cultivating regions worldwide causing high yield loss. It is caused by the fungal pathogen Fusarium fujikuroi. Varying degree of resistance or susceptibility to bakanae disease had been reported among Korean japonica rice varieties. We developed a modified in vitro bakanae disease bioassay method and tested 31 Korean japonica rice varieties. Nampyeong and Samgwang varieties showed highest resistance while 14 varieties including Junam and Hopum were highly susceptible with 100% mortality rate. We carried out mapping QTLs for bakanae disease resistance with four F2:F3 populations derived from the crosses between Korean japonica rice varieties. The Kompetitive Allele-Specific PCR (KASP) markers developed in our laboratory based on the SNPs detected in Korean japonica rice varieties were used in genotyping F2 plants in the populations. We found four major QTLs on chromosome 1, 4, 6, and 9 with LOD scores of 21.4, 6.9, 6.0, and 60.3, respectively. In addition, we are doing map-based cloning of the QTLs on chromosome 1 and 9 which were found with Junam/Nampyeong F2:F3 population and Junam/Samgwang F2:F3 population, respectively. These QTLs will be very useful in developing bakanae disease resistant high quality rice varieties.

• Korean Journal of Microbiology
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• 제25권4호
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• pp.255-261
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• 1987

Five independent Actinomycetes harboring plasmids were isolated from soil. Molecular weight of these plasmids was 55kb, 6.2kb, 4.4kb, 55kb and 7.0kb, respectively. Among them small and apprent high copy number plasmids, pJY501 of 4.4kb and pHY711 of 7.0kb, were selected. The plasmids purified by CsCl-EtBr density gradient centrifugation preserved the conformation of supercoiled covalently closed circular molecule, and an apparent copy number was estivated about 150 and about 35 per chromosome. The isolates carrying plasmids were assigned to the genus Streptomyces. For the purpose of introducing selection markers into the isolated plasmids, the tsr fragmemt of pIJ702 was inserted into the BclI site of pJY 501 and pJY711. And the recombinant plasmids constructed designated as pJY502 and pJY712 respectively.

• Applied Biological Chemistry
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• 제39권6호
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• pp.430-436
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• 1996

The induction by xylose and repression by glucose of xylose isomerase(XI) were investigated to elucidate the regulation for production of XI in Escherichia coli. Regulation for expression of xyIA gene which codes XI is under control of xylR which is a regulatory gene for xylose catabolism. When xyIR gene was resided in chromosome, the inductions of XI by the addition of 0.4% xylose were increased to 1.9 and 1.7-fold in case of locating on multicopy(pEX202/DH77) and low copy Plasmid(pEX102/DH77), respectively, as compared with that of xylA gene which was resided in chromosome(JM109). xyIR gene product derived from xyIR gene on chromosome might react to xylA gene on the plasmid as same as xylA gene on chromosome. In JM109 and xylA transformant; pEX202/DH77 and pEX102/DH77, the inductions of XI were completely repressed by the addition of 0.2% glucose and these catabolite repressions were derepressed by the addition of 1 mM cAMP In comparison with the addition of 0.4% xylose only for the induction XI was inductively produced 1.7 to 2-fold with the addition of xylose plus 1 mM cAMP in DM minimal media. pEX13/TP2010, xylA transformant of the deficient mutant($xyl^-,\;cya^-$; TP2010) of XI and cAMP production, did not induce XI by the addition of xylose only but induced in case of simultaneous addition of xylose and cAMP. These results show that cAMP and xylose are the indispensable effectors for the induction and derepression of Xl in E. coli.

• Journal of Oral Medicine and Pain
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• 제33권1호
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• pp.59-66
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• 2008

Ribosomal Protein S4Y(RPS4Y) gene is the human sex-linked gene on the Y chromosome. There are a number of reports on the sex determination using RPS4Y gene analysis for prevention and diagnosis in sex-linked disease. Thus RPS4Y gene is a reliable genetic marker for sex determination in forensic medicine. In general, the sex determination of an unidentified body can be achieved based on anatomical characteristics, but sometimes sex determination was considered to be difficult such as pre-adolescent bodies or decomposed, mutilated bodies. In this case, Sex determination using PCR method in human teeth produces good results. Because human teeth have a great structural durability, the DNA well preserved in the teeth. So author isolated nuclear DNA from the 20 human teeth(10 males, 10 females), performed to detect RPS4Y gene by PCR method. Samples were divided four group(10 pulp and 10 dentinal tissue in male, 10 pulp and 10 dentinal tissue in female). It was found that detection of RPS4Y gene for sex determination was possible in all the male pulp tissues and 6 out of 10 male dentinal tissues. But there was not detected in female pulp and dentinal tissues. In the view of this results demonstrates the possibility that detection of RPS4Y gene with other sex chromosome genes from the human teeth is useful to sex determination in forensic medicine.

• Journal of Microbiology and Biotechnology
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• 제7권5호
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• pp.360-362
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• 1997

A transposon Tn5 mutant of Rhodobacter sphaeroides 2.4.1 was isolated for its impaired ability of growth on minimal medium containing ${\beta}$-hydroxybutyric acid as a sole carbon source. The mutant, R. sphaeroides S7 showed approximately 6-fold decrease in ${\beta}$-hydroxybutyrate dehydrogenase activity compared with that of wild type. In R. sphaeroides S7 the Tn5 was located in DNA region corresponding to a 4.2-kb EcoRI DNA fragment of R. sphaeroides 2.4.1 chromosome.

• Korean Journal of Microbiology
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• 제27권2호
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• pp.92-97
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• 1989

the vector, pGUR19, for Rhizobium gene manipulation, was constructed by combining the replication and mobilization function of indigenous multicopy plasmid from Acacia(Robinia pseudoacacia L.) Rhizobia sp86 with E. coli cloning vehicle, pBR322. The vector could be efficiently mobilized by RP4 tra function incorporated into chromosome of E. coli named SM10 and efficiently transferred to various gram negative hosts including Rhizobium and Afrobacterium by transformation. Mobilization frequency of the constructed vector was ranged from $1.2\times 10^{-2}$ (E.coli HB 101) to $4.6\times 10^{-4}$ (A. tumefaciens 15955) and transformation frequency was ranged from $5.4\times 10^{-7}$(E. coli HB101) to $1.2\times 10^{-10}$ (A. tumefaciens 15955). The vector, pGUR19, was stably replicated and maintained in a variety of Rhizobium and Agrobacterium.

• Korean Journal of Breeding Science
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• 제43권6호
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• pp.620-624
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• 2011

'Hwaweon 4' was developed from a cross between the African upland cultivar, 'Moroberekan' and 'Ilpumbyeo' based on marker-aided backcross selection. The recurrent parent 'Ilpumbyeo' is a high grain quality cultivar with medium to late maturity. 'Hwaweon 4' is nearly isogenic to 'Ilpumbyeo' except a small Moroberekan introgressed segment on chromosome 4 harboring the resistance gene for blast. The preliminary and replicated yield trial was conducted at Chungnam National University in 2006 and 2007. The local adaptability test was carried out by the National Seed Management Office (NSMO) from 2008 to 2009. This cultivar was registered to NSMO with a cultivar designated as 'Hwaweon 4'. This cultivar averaged 76 cm in culm length and has medium growth duration. Milled rice of 'Hwaweon 4' is translucent and the grain quality traits are comparable to those of the recurrent parent. It has low protein content. The yield potential of 'Hwaweon 4' in grain was about 6.31 MT/ha at the ordinary fertilizer level for two years. This variety showed highly resistance reaction at the blast nursery test at four locations and also at the sequential planting method. This resistance is due to the resistance gene designated as Pi45(t) on chromosome 4 introgressed from the donor parent, 'Moroberekan'. The Pi45(t) gene would be useful inenhancing resistance to blast in rice breeding program.

• Journal of Plant Biotechnology
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• 제29권4호
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• pp.259-264
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• 2002

Induction of embryogenic callus from Allium wakegi Araki explants was promoted on medium containing 2,4-D, and production of abnormal embryos from the embryogenic callus increased as 2,4-D concentration was raised. Shoot tip was found to be the best explant source for embryogenic callus formation followed in the order by bulb scale and leaf section. Medium containing 0.09 M sucrose was effective for embryogenic callus production. The regenerants from embryogenic callus on medium containing 2,4-D and BA at different concentrations was consisted of diploids, tetraploids and a few mixaploids of 2n＋4n, and their chromosomal aberration rate ranged from 8.0 to 33.3%. Frequency of chromosomal aberrants was the highest (18.7%) in the regenerants obtained from bulb scale-derived embryogenic callus among others. Plant regeneration rate was high (33.5%) from the shoot tip-derived embryogenic callus and the frequency of chromosomal aberrants was very low (7.0%). The plantlets regenerated on medium containing 0.26 M sucrose resulted in high chromosomal aberrants. The regenerants on medium containing sucrose at 0.09∼0.20 M produced chromosomal aberrants at around 15.2∼16.6%.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제35권6호
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• pp.532-538
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• 1990

This experiment was carried out to establish the efficiency of crop breeding on comparison of combination methods of single, 3-way, and double crosses and combination order of 4 winter wheat which were different in origin, source, and plant types, On comparison of 4 crossing modes, there appeared the earliest heading and the highest grain yield in double cross, and decreased in 3-way. single crosses. and parents in order, There showed the significant mean squares of GCA and SCA in 4${\times}$4 diallel analysis for grain yield and yield components. Grumil and Bezostaya 1 exhibited highest GCA effect of grain yield which appeared the actual highest grain yield. There appeared the highest SCA-effect in F$_1$ (Eunpamil/Bezostaya 1) showing 4.22. Of the 3 double crosses there exhibited the highest grain yield in F$_1$ (Grumil/Eunpamil/ /Lanota/Bezostaya 1). Two single crosses for this double cross ---F$_1$ (Grumil/Eunpamil) and F$_1$ (Lancota/Bezostaya 1) --- do not revealed directly for this yield, but combined each other by chromosome switch as combination of F$_1$ (Grumil/Lancota), F$_1$(Grumil/Bezostaya 1), F$_1$(Eunpamil/Lancota) and F$_1$(Eunpamil/Bezostaya 1) which appeared the higher grain yields and SCA-effects. Of the six 3-way crosses. F$_1$ (Lancota/Bezostaya 1/ /Eunpamil) expressed the highest grain yield. Its combinations were F$_1$ (Lancota/Eunpamil) and F$_1$ (Bezostaya 1/Eunpamil) combined by chromosome switch, which its grain yield and SCA-effect were higher.

• YAKHAK HOEJI
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• 제52권4호
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• pp.279-282
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• 2008

Plasmids were isolated from 15 tetracycline (Tc) resistant S. aureus. Two small tetracycline resistance plasmids, pKH16 and pKH17, have been isolated from Staphylococcus aureus JY10 and Staphylococcus aureus JY22, respectively and the complete nucleotide sequences of those plasmids have been determined. pKH16 consisted of 4,442 bp and showed high identity to pKH6 (99% matching percentage) isolated in 1989 from S. aureus SA2. pKH17 consisted of 4,441 bp and showed less identity to pKH6 (95% matching percentage) than pKH16. PCR analysis showed that tetK and tetM did not exist in ten large plasmids isolated from ten Tc resistant S. aureus. Twelve Tc resistant S. aureus showed reistance both to Tc and Mn and we might analogize that twelve Tc resistant S. aureus had tetM in their chromosome.