96 BC3F5 introgression lines derived from a cross between Hwaseong and O. rufipogon were genotyped with 131 simple sequence repeat (SSR) markers to identify and characterize quantitative traits loci (QTLs) associated with grain quality traits in rice. 96 BC3F5 lines displayed a wide range of variation for days to heading and agronomic traits. Results indicated that one major QTL (qDTH6) on chromosome 6 was associated with significant variation for days to heading. 83 lines without the O. rufipogon segment at qDTH6 were selected and analyzed for grain quality traits. QTL analysis was conducted for two groups, 96 and 83 introgression lines, and a total of 25 QTLs were detected for rice quality traits. 16 QTLs were detected in a group of 93 lines, 11 QTLs detected in a group of 83 lines, and 2 QTLs were commonly identified in both groups. Most of the QTLs detected in this study were located on the same or adjacent regions as those reported by the previous studies, and the wild alleles negatively affected quality traits. In contrast, the wild allele at qGCR9 for the glossiness of cooked rice on chromosome 9 contributed to an increase in glossiness which is positively correlated with rice eating quality. Three ILs with the wild allele at qGCR9 displayed better eating quality than the recurrent parent, Hwaseong. To confirm the effect of qGCR9, high density mapping of the qGCR9 with a series of NILs will be conducted.

The objective of this study were to identify QTLs for agronomic traits using a set of introgression lines carrying wild rice (Oryza rufipogon) segment in cultivated rice (ssp. japonica cv. Hwaseongbyeo). Ninety-six ILs were evaluated for seven agronomic traits, amylose and protein contents. The proportion of the recurrent genome in ILs ranged from 87.8 to 100%, with an average of 96.7%. The mean number of homozygous and heterozygous donor segments were 2 (ranging 0-7) and 1.7 (ranging 0-6), respectively, and the majority of these segments had size less than 10 cM. A total of 22 quantitative trait loci were identified for 9 traits and each QTL explained 7.2% to 56.6% of the phenotypic variance. Some QTLs were clustered in a few chromosomal regions. A first cluster was located near RM527 on chromosome 6 with QTLs for culm length, panicle length, days to heading, 1000-grain weight and protein content. Three ILs with high spikelets per panicle compared to the recurrent parent were selected to detect and fine map the wild segments responsible for this variation. The results will be discussed.

We investigated outer appearance of brown rice(BR) and its anthocyanin content of Josangheugchal a colored rice variety as affected by different transplanting date(from May 15 to June 24, 10 day interval, 5 times). Thickness of BR was mainly 1.6～2.0mm which occupied 96.7% ~ 99.5% under different transplanting date. As transplanting time was late, mode of thickness of BR was clearly decreased : 2.0mm on May 15 and May 25, 1.9mm on June 4 and June 14, and 1.8mm on June 24. There was statistically significant difference in length, width and 1000 grain weight of BR according to both transplanting date and thickness of BR. There was highly significant positive corelation between thickness and length of BR and between thickness and 1000 grain weight of BR. Anthocyanin content linearly increased from 119.7mg/100g on May 15 to 384.4mg/100g on June 24 as transplanting time was late, and was highest in 1.8~1.9mm thickness of BR. Coefficient of variation for anthocyanin content by thickness of BR was lowest on June 24. According to the facts stated above it is recommendable to transplant Josangheugchal in late June to produce highly marketable colored rice.