• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.421-427
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• 2006

To investigate the relationships among the traits related seed dormancy in rice, viviparous germination, dry-heat tolerance and seed longevity were tested using 164 M/G RILs ($F_{17}$) derived from the cross between Milyang 23 (Indica/Japonica) and Gihobyeo (Japonica). At 40 days after heading, the viviparous germination rates of Milyang 23 and Gihobyeo were 0.0 and 7.0%, respectively. The averaged viviparous germination rate of 164 MIG RILs was 3.2%, and their range was from 0.0 to 50.9%. In dry-heat treatment at $90^{\circ}C$ for 24 h followed by the pre-drying at $40^{\circ}C$ for 2 days, Milyang 23 showed higher germinability (98.6%,2.7 days to $T_{50}$) than Gihobyeo (37.6%, 12.9 days to $T_{50}$), and the mean germination rate of 164 M/G RILs was 72.4%. In 54 months after harvest, the germinability in Milyang 23 and Gihobyeo were 90% and 0%, and 71 lines among 164 M/G RILs showed the germinability over 90%. The relationship between seed longevity and dry-heat tolerance was linearly correlated with high positive correlation coefficient. The relationships between seed longevity and viviparous germination, and viviparous germination and dry-heat tolerance were linearly correlated with high negative correlation coefficient. Milyang 23 had higher tolerance against high dry-heat, viviparous germination and long-term storage than Gihobyeo, and 164 M/G RILs showed the medium values of parents.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.160-166
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• 2004

This study was carried out to get the basic informations regarding the varietal variations for the physicochemical properties such as protein content, amylose content, fatty acid content, grain quality values and color properties such as lightness value, chroma and hue for the 164 recombinant inbred lines(RILs) of Milyang 23 and Gihobyeo(M/G) at the experimental farm in the Sangji University. The principal component analysis and heritability study were conducted for this experiments. The rapidity of grain filling(RCF) for the 164 M/G RILs could be classified into four groups such as slow maturing group less than 41％, mid-slow maturing group 41∼60％, fast maturing group 61∼80％ and very fast maturing group more than 81％ based on the rapidity of grain filling rate. The slow maturing group of RGF showed a little bit higher protein content 9.1％, compared to the other RGF groups. However, the amylose content of all the RGF groups revealed the same content by the groups. The very fast maturing group of RGF showed longer grain length in brown rice compared to other RGF varietal groups, in case of grain width in brown rice showed shorter than any other groups. The alkali digestive value which was so much related to gelatinization temperature showed 3.40 degree at fast maturing group of RGF in M/G RILs. However, the very fast maturing group of RGF revealed 4.31 degree of alkali digestive value. The principal component analysis was performed by the chemical and color properties such as quality value, protein content, amylose content, alkali digestive value, fatty acid content, lightness value, chroma and hue for M/G RILs. The first principal component was able to explained upto 36％ to total informations. It was corresponded to quality value, protein content, amylose content, fatty acid content, lightness value and a-value(green -1 red). The characters regarding grain quality showed high heritable properties more than 75％ of heritability, but color characters appeared relatively lower heritability compared to grain quality.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.126-127
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• 2004

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.539-545
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• 2004

The purpose of this study was to locate the quantitative trait loci (QTL) associated with quality properties in the recombinant inbred lines derived from the 'Milyang 23' and 'Gihobyeo' cross. Four quality-related traits; protein content, amylose content, fat acid content and sensory value were measured. Eight QTLs for protein content were detected on chromosomes 1 (two loci), 3, 6, 7 and 8 (three loci), each accounting for $6.0\%\~15.2\%$ of the phenotypic variation. Three QTLs for amylose content were detected on chromosomes 6 and 7 (two loci), each explaining from $7.3\%\;to\;24.4\%$ of the phenotypic variation. Six QTLs for fat acid content were detected on chromosomes 2 (two loci), 3, 6 (two loci) and 7, each explaining form $5.5\%\;to\;14.0\%$ of the phenotypic variation. Six QTLs for sensory value were detected on chromosomes 2, 6, 7(two loci) and 8 (two loci), each accounting for $5.5\%\~10.3\%$ of the phenotypic variation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.565-570
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• 2006

The viviparous germination (VG) with lodging caused the yield reduction and quality deterioration in rice. We carried out the evaluation of VG tolerance (on the 40th day after heading) and mapping QTLs associated with VG tolerance using the recombinant inbred lines (M/G RILs) from a cross between Milyang 23 (japonica/indica) and Gihobyeo (japonica). The VG rates of Milyang 23 and Gihobyeo were 0.0 and 7.0%, respectively. The averaged VG rate of 162 M/G RILs was 7.7%, and their range was from 0.0 to 50.9%. Of the 162 RILs, 144 lines were tolerant less than 10%, and 18 lines were susceptible more than 10%. Using the M/G RIL Map, three QTLs associated with the viviparous trait were detected on chromosome 2 (qVG 2-1 and qVG 2-2) and 8 (qVG 8). qVG 2-1 was linked to RM 32D and RZ 166, and had LOD score of 2.97. qVG 2-2 was tightly linked to E13M59.119-Pl and E13M59.M003-P2, and showed higher LOD score of 3.41. qVG 8 was linked to RM33 and TCT116, and had LOD score of 2.67. The total phenotypic variance explained by the three QTLs was about 24.4% of the total variance in the population. The detection of new QTLs associated with VG tolerance will provide important informations for the seed dormancy, low temperature germination, or comparative genetics.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1760-1772
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• 2006

Mature acetylcholinesterase (AChE) gene (gm, 1,836 bp) was cloned from the housefly and successfully expressed in the E. coli CodonPlus (DE3) RIL system (GM-E, 72 kDa) with a yield of 1,630 mU/g fresh cells. Using the gm, 10 kinds of mutants were constructed and expressed for enhancing sensitivity to insecticides. The sensitivity of these mutants to five kinds of organophosphate (OP) and three carbamate insecticides was investigated by measuring the apparent bimolecular inhibition constant ($k_i=k_2/K_d$). Surprisingly, the sensitivity of quadruple mutant IGFT was enhanced as much as 7-fold for acephate, 164-fold for demeton-S-methyl, 484-fold for dichlorvos, 523-fold for edifenphos, 30-fold for ethoprophos, 30-fold for benfuracarb, 404-fold for carbaryl, and 107-fold for furathiocarb, compared with that of GM-E, although the sensitivity of each single point mutant was slightly increased. These mutational studies indicated that (i) contradictory to Walsh et al. [39], the residue 327 is the important key residue for enhancing sensitivity as much as the residue 262, (ii) the residue 82 and additional residues of 234, 236, and 585 are also important, and (iii) sensitivity was cooperatively accelerated as the number of strategic mutations increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.259-268
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• 2006

Miniature inverted transposable elements (MITEs) are abundant genomic components in plant including rice. MITE-transposon display (MITE-TD) is an Amplified Fragment Length Polymorphism (AFLP)-related technique based on MITE sequence. In this study, we used the MITE-AFLP for the analysis of diversity and relation-ship of the 114 japonica accessions. Of the several MITEs, the mPing family was applied to detect polymorphisms based on PCR amplification. The BfaI adaptor primer and the specific primer derived from mPing terminal inverted repeat (TIR) region were used to PCR amplification of 114 accessions. Nine primer pairs produced a total of 160 polymorphic bands. PIC values of the polymorphic bands generated by nine primer pairs ranged from 0.269 (BfaI + ACT) to 0.426 (BfaI + T). Each accession revealed a distinct fingerprint with two primer combinations, BfaI + G and BfaI + C. Cluster analysis using marker-based genetic similarity classified 114 accessions into five groups. MITE-AFLP markers were genetically mapped using a population of 80 BILs (BC1F7) derived from a cross between the rice accessions, Milyang 23 and Hapcheonaengmi 3. Eight of the markers produced with the primer pair BfaI + 0 were mapped on chromosomes 1, 2, 4, 5, 7, and 9. Considering that one MITE-AFLP marker on chromosome 7 was tightly linked to the Rc gene, the MITE-AFLP markers will be useful for gene tagging and molecular cloning.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.291-294
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• 2008

Amylogram properties such as peak viscosity, hot viscosity, cool viscosity, breakdown, pasting consistency and setback were investigated by the Rapid Visco Analyzer and interpreted by the relationship among amylogram properties according to the varietal groups classified by the rapidity of grain filling (RGF) which was calculated by the percentage of grain weight at 15 days after heading to 40 days after heading. The 164 rice recombinant inbred lines from the cross of Milyang23 and Gihobyeo were used to get the basic information regarding the amylogram properties. The used recombinant inbred lines could be grouped into 4 varietal groups such as slow maturing (less than 40% of RGF), mid-slow maturing (41-60% of RGF),mid-fast maturing (61-80% of RGF), and fast maturing (more than 81% of RGF) groups based on the RGF. The peak viscosity and setback showed regular tendency according to the varietal groups classified by the RGF. Positive significant correlations were found between pasting consistency and setback, however negative significant correlations were found between breakdown and setback in all varietal groups.