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.

In the previous study (Yuan et al. 2009), a quantitative trait locus (QTL) for grain weight was detected on the short arm of chromosome 5 using an advanced backcross lines (BC3F3) between Hwayeongbye (Oryza sativa) and W1944(Oryza rufipogon Griff.) .For detection of gw5 locus, a line CR6 (BC3F4) was selected and crossed to Hwayeongbyeo produce S1F2 and S1F3 population. And a plant from S1F3 population, carried W1944 homozygous segment for target region at gw5 was crossed to Hwayeong to produce S2F2 population. All these population including some S1F3 lines were grown in the field in 2007, 2008 and 2009, respectively (fig1). Frequency distribution of grain weight followed the Mendelian ratios(3:1) for single locus segregation (Χ2=1.22, 0.76, 1.34 in 2007, 2008 and 2009 respectively).In Hwayeongbye genetic background, the W1944 allele at the gw5 locusde creased grain weight, QTL analysis showed that gw5 co-segregated with RM18003 and RM194 (R2=62.7, 69.5 and 37.1% in 2007, 2008 and 2009 respectively). Addition, five QTLs plant height, culm length, secondary branch, spikelet number perplant and rationing ability were detected in the region around gw5, in 2008 and 2009. Substitution mapping with 32F3 lines, gw5 QTL was flanked by two SSRmarkers, RM18003 and RM194, in a300kb to 1.7Mb physical distance region,. QTL analysis indicated that 5 others QTLs plant height, culm length, secondary branch, spikelet number per plant and rationing ability were tightly linked.

QTL analysis for cold tolerance-related traits was conducted using 75 introgression lines (IL) developed from a cross between a japonica weedy rice and Tongil-type rice. A molecular linkage map consisting of 136 SSR markers was constructed to identify QTLs associated with cold tolerance. 75 ILs and the parents were evaluated for three traits associated with cold tolerance: seedling height and SAPD values at the seedling stage. The plants were grown for 15 days in the low temperature condition (13/20℃ day/night) and the control condition (25/20℃ day/night) in the growth chamber. A total of six QTL were identified for two traits and phenotypic variance explained by each QTL ranged from 4.3% to 35.7%. Among two QTL for seedling height, one QTL, sh1 for seedling height was detected at both conditions. The other QTL on chromosome 6 was detected in the low temperature condition. Four QTL were identified for SPAD value and two were detected on chromosomes 2 and 5. At these loci, Milyang 23 alleles increased the SPAD value. The other two QTL on chromosomes 1 and 4 were detected at the low temperature plot. At these loci, Hapcheonaengmi 3 alleles increased the SPAD values. These results indicate that Hapcheonaengmi 3 alleles might increase tolerance to low temperature in the Milyang 23 background because SPAD value is positively correlated with chlorophyll content and N content in rice. The markers linked to low temperature tolerance at the seedling stage would be useful in selecting for lines with enhanced cold tolerance in a breeding program.

β-carotene producing transformants were produced in the background of "Nagdong", a japonica rice cultivar. Introgression of the caroteniod locus into the elite cultivar "Ilpum". Was started to initiate a backcrossing program, we surveyed 220 SSR markers and found that 38% of them were polymorphic between the “Ilpum” as the recurrent parent and "Nagdong" transfomed as a recipient parent. First, backcross progenies have been produced and genotyped by the transgene specific PCR-based marker. Blast search indicated that the transgene PAC4-2 was located between SSR markers, RM5631 and RM5916. We produced 240 BC3F2 plants derived from thirteen BC3F1 plants containing the caroteniod gene. To develop near isogenic line, additional experiments including target and background selection are being performed using SSR markers. Traits of agronomic importance such as heading date, panicle number and culm length will also be evaluated. The results will be discussed.

Camelina sativa (L.) Crantz, known as popular names "gold-of-pleasure" or "false flax" is an alternative oilseed crop that can be grown under different climatic and soil condition. Up to date, however, the genomic information of camelina has not been studied in detail. Therefore, a cDNA library was constructed and characterized from young leaves. The constructed cDNA library incorporated of 1334 cDNA clones and the size of the insertion fragments average was 736 base pair. We generated a total of 1269 high-quality expressed sequence tags (ESTs) sequences. The result of cluster analysis of EST sequences showed that the number of unigene was 851. According to subsequent analysis, the 476 unigenes were highly homologous to known function genes and the other 375 unigenes were unknown. Remaining 63 unigenes had no homology with any other peptide in NCBI database, indicating that these seemed to be novel genes expressed in leaves of camelina. The database-matched ESTs were further classified into 17 categories according to their functional annotation. The most abundant of categories were protein with binding function (27%), metabolism (11%), subcellular localization (11%), cellular transport, transport facilities and transport routes (7%), energy (6%), regulation of metabolism and protein function (6%). Our result in this study provides an overview of mRNA expression profile and a basal genetic information of camelina as an oilseed crop.