Background : Tetraploid plants are bigger in the size of fruits, leaves, stems, and roots than diploid plants due to bigger cells attributed to chromosome multiplication. The advantage of tetraploid plants includes breakdown of self-incompatibility and increase of disease resistance. This study was carried out to gain tetraploid resources for breeding of new boxthorn varieties having pest resistance, higher yield, and self-compatibility. Methods and Results : Tetraploid lines for this study were C0148-10 and C0412-1 from Cheongyang-jaerae (CJ), M0148-94 and M0148-120 from Myongan (MA), B0148-43 and B0148-78 from Bulro (BL), D0148-62 and D0148-72 from Cheongdae (CD), and Y0148-2 and Y0148-24 from Youngha (YH). Flower width ranged 13.2～17.4mm. Flower, pollen and anther were bigger than the mother plants. Pollen germination rate of the tetraploid lines ranging 36.1～58.8% was lower than mother plants (46.5～67.6%). Self-fertilization rate in 4 varieties, MA, BL, CD and YH was low as 1.3%, 4.0%, 1.4% and 4.7% respectively indicating that mother plants are self-incompatible. Self-fertilization rate in tetraploid lines was higher as 58.1～87.5% and B0148-43, M0148-120, and D0148-72 showed the highest self-fertilization rate over 80%. Conclusion : Tetraploid lines showed higer self-fertilization rate than mother plants that they were expected as valuable resources for new boxthorn variety having self-compatibility.

Background : Tetraploid plant is bigger in size of organs like leaf, stem, fruit, and root than diploid plant by chromosome doubling. Also, Self-ìncompatibílity disappeares and disease resistance is strengthened in tetraploid plant. To breed new boxthorn variety having bigger fruit, higher yield, pest tolerance, and, self-compatibílity, tetraploids was induced for tetraploid breeding resources by colchicine treatment in each boxthorn variety. Materials and Methods : Colchicine was treated in Myongan, Cheongdae, Bulro, and Youngha for 0.1% concentration and 48 hours. Polyploid was identified by flow cytomertry(Partec, PA-1) and chromosome numbers of polyploid individuals were examined by aceto-carmine stain. Conclusion : Colchicine was treated in Myongan, Cheongdae, Bulro, and Youngha for 0.1% concentration and 48 hours. Tetraploid was induced as 13, 9, 6, and 5 individuals in Myongan, Cheongdae, Bulro, and Youngha respectively by above colchicine treatment.

백진주'는 1991년 하계에 개화 후 수정된 양질다수성 품종인 일품벼 수정난을 26±1℃ 암조건에서 1 mM의 MNU 용액에 45분간 침지한 후 24시간 동안 수세하였다. 처리한 식물체를 온실에서 등숙시켜 종실을 수확하여 돌연변이 M1세대 697개체를 얻었다. 1992년 하계 온실에서 M2세대 15개체를 선발하여 1992/'93 동계 온실에서 M3 집단을 육성하였다. M4 세대부터는 포장에서 계통 선발법에 의해 주요 병해충 및 미질검정을 병행하여 다양한

화원4호'는 '일품벼'의 농업적 특성에 모로베레칸의 도열병 저항성 유전자가 이입된 근동질계통을 육성하기 위해 '일품벼'와 모로베레칸을 교배하고, 계속적인 여교배와 MAS를 병행 실시하여 유망한 계통 CR502-3-2 계통을 선발하였다. 생산력검정 시험 결과 조사된 형질 중 도열병저항성을 제외한 기타 형질에서는 '일품벼'와 유사한 근동질계통으로, 품종보 호원 출원 조건에 부합하여 '화원4호'로 명명하고 품종보호원을 출원하였다. 1. 출수기는 보통기재배에서

Gluten is the main functional component of wheat, and is the main source of the viscoelastic properties in a dough. One of the gluten group is glutenin, which is composed of high molecular weight (HMW) and low molecular weight (LMW) subunits. The HMW glutenin subunits (HMW-GS) have been shown to play a crucial role in determining the processing properties of the grain. They are encoded by the Glu-1 loci located on the long arms of homeologous group one chromosomes, with each locus comprising two genes encoding x- and y-type subunits. The presence of certain HMW subunits is positively correlated with good bread-making quality. The highly conserved N- and C- terminal contaning cystein residues which form interand intra-chain disulphide bonds. This inter chain disulphide bonds stabilize the glutenin polymers. In contrast, the repetitive domains that comprise the central part of the HMW-GS are responsible for the elastic properties due to extensive arrays of interchain hydrogen bonds. In this review, we discuss HMW-GS, HMW-GS structure and gluten elasticity, relationship between HMW-GS and bread wheat quality and genetic engineering of the HMW-GS.

Beta-carotene producing transformants were produced in the background of 'Nagdongbyeo', a Japonica rice cultivar. Introgression of the carotenoid locus in the transformant, PAC4-2 into the elite cultivar 'Ilpumbyeo' was started. To initiate a backcrossing program, we surveyed 220 SSR markers and found that 38% of them were polymorphic between 'Ilpumbyeo' as a recurrent parent and the PAC4-2 as a recipient parent. The selection strategy comprising foreground and background selection was employed. First, foreground selection was practiced in BC1, BC2, and BC3 generations using the transgene specific PCR-based marker in addition to visual scoring of the seed color. Marker-based background selection combined with phenotypic selection was employed from BC3F2 to BC3F4 generations. Blast search indicated that the transgene PAC4-2 was located between SSR markers, RM6 and RM482. 240 BC3F3 and 63 BC3F4 lines were evaluated for four agronomic traits including days to heading. Most of the lines were similar to Ilpumbyeo in agronomic traits evaluated. The percentage of PAC4-2 genome ranged from 4% to 21% with a mean of 12.5%, which was higher than the expected for an unselected BC3 backcross population. This could be explained by the fact that two genes for beta-carotene and the stripe virus resistance were targeted in this study. We selected 10 representative BC3F5 lines from 63 BC3F4 lines based on agronomic traits and carotenoids content. The selection strategy would be appropriate for the introgression of beta-carotene gene in a breeding program.

1. 선행 연구에서 염색체 3번의 RM60~RM231 부근에서 종자중, 수당립수에 관여하는 QTL이 탐지되었고, 이를 확인하기 위하여 이 지역에 크기와 위치가 다른 O. glaberrima 단편이 이입된 5 계통을 선발하여 표현형을 조사하였다. 실험 결과 계통별로 출수기, 임실률, 수당립수, 종자중을 제외한 형태적 특성들이 밀양23호와 비슷한 양상을 보였다. 이는 대부분의 염색체 지역이 밀양23호로 회복되었기 때문이라고 보여진다. 2. 유전자의 위치를

본 연구는 모로베레칸의 잎도열병 저항성유전자를 탐색하고, 이 저항성유전자와 연관된 분자표지를 탐색하기 위해 수행되었다. 도열병에 이병성인 일품벼와 도열병에 강한 모로베레칸을 교잡하여 육성된 140개 BC3F3 계통을 도열병 균계 반응을 통한 저항성 유전자 탐색에 이용하였다.

미성숙 종자로부터 추출된 전체 RNA를 이용하여 합성한 cDNA와 LMW-GS 특이 프라이머세트를 이용하여 43개의 LMW-GS 유전자를 분리하였다. 각각의 유추 아미노산은 상동성이 높은 20개의 시그널 펩타이드, N-말단 영역, 반복서열영역 그리고 C-말단 영역을 가지며 C-말단 영역에 분자내 혹은 분자간 이황화 결합을 형성하는 전형적인 8개의 시스테인을 가지고 있었다. 이들 시스테인의 위치는 첫번째, 일곱번째를 제외하고는 보존되어 있었다. Ikeda

The objectives of this study were to identify QTLs for agronomic traits using introgression lines from a cross between a japonica weedy rice and a Tongil-type rice. A total of 75 introgression lines developed in the Tongil-type rice were characterized. A total of 368 introgressed segments including 285 homozygous and 83 heterozygous loci were detected on 12 chromosomes based on the genotypes of 136 SSR markers. Each of 75 introgression lines contained 0-9 homozygous and 0-8 heterozygous introgressed segments with an average of 5.8 segments per line. A total of 31 quantitative and 2 qualitative loci were identified for 14 agronomic traits and each QTL explained 4.1% to 76.6% of the phenotypic variance. Some QTLs were clustered in a few chromosomal regions. A first cluster was located near RM315 and RM472 on chromosome 1 with QTLs for 1,000 grain weight, culm length, grain width and thickness. Another cluster was detected with four QTLs for 1,000 grain weight, grain length, grain width and grain length/width ratio near the SSR marker RM249 on chromosome 5. Among the 31 QTLs, 9 (28.1%) Hapcheonaengmi3 alleles were beneficial in the Milyang23 background. ILs would be useful to confirm QTLs putatively detected in a primary mapping population for complex traits and serve as a starting point for map-based cloning of the QTLs. Additional backcrosses are being made to purify nearly isogenic lines (NILs) harboring a few favorable Hapcheonaengmi3 alleles in Milyang23 background.

In a previous study, we mapped 12 QTLs for 1,000 grain weight (TGW) in the 172 BC2F2 lines derived from a cross between Oryza sativa ssp. Japonica cv. Hwaseongbyeo and O. rufipogon. These QTLs explained 5.4 – 11.4% of the phenotypic variance for TGW. Marker-aided selection combined with backcrosses was employed to develop QTL-NILs for each QTL. BC2F2 lines with each target QTL were backcrossed to Hwaseongbyeo twice and then allowed to self to produce BC4F5 populations. SSR markers linked to TGW were employed to select QTL-NILs with the respective target QTL. Six QTL-NILs with the recurrent parent, Hwaseongbyeo were evaluated for nine traits for three years from 2007 and 2009. Differences were observed between each of the 6 QTL-NILs and Hwaseongbyeo in TGW. In addition to TGW, these QTL-NILs displayed differences in other agronomic traits possibly indicating a tight linkage of genes controlling these traits. The direction of the QTL for TGW in 6 QTL-NILs was consistent as in the BC2F2 lines from the same cross. Difference in TGW between each of the QTL-NILs and Hwaseongbyeo was associated with the difference in one or two grain shape traits; grain length, grain width, and grain thickness. SSR markers linked to the QTL for TGW will facilitate selection of the grain shape character in a breeding program to diversify grain shape and provide the foundation for map-based gene isolation. Also, the QTL-NILs developed in this report and the progenies from crosses between the QTL-NILs will be useful in clarifying epistatic interactions among QTLs for TGW.