This study was conducted to identify QTLs for some agronomic traits under two different N-fertilizer conditions. A recombinant inbred population (DT-RILs) between Dasanbyeo (a tongil type rice, derived from an indica × japonica cross and similar to indica in its genetic make-up) and TR22183 (a Chinese japonica variety), consisting of 166 F8 lines, was developed and used for mapping. A frame map of 1,409 cM containing 113 SSR and 103 STS markers with an average interval of 6.5 cM between adjacent marker loci was constructed using the DT-RILs. The DT-RILs were cultivated in ordinary N-fertilizer (N-P2O5-K2O=100-80-80 kg/ha) condition and low N-fertilizer (N-P2O5-K2O=50-80-80 kg/ha) condition in order to compare the different N-fertilizer effects. Grain yield was positively correlated with spikelet number in both conditions. Path analysis revealed that spikelet number is the most positive contributor to grain yield. Twenty-nine single QTLs (S-QTLs) and sixty-five pairs of epistatic loci (E-QTLs) were identified for days to heading, culm length, panicle length, panicle number, spikelet number, spikelet fertility, 1000-grains weight and grain yield in both N-fertilizer conditions. The phenotypic variance explained by these S-QTLs and E-QTLs ranged from 8.8% to 61.1% and from 10.0% to 55.6%, respectively. The total phenotypic variance explained by all the QTLs for each trait ranged from 15.4% to 92.3%.

This study was carried to examine the changes in kernel-greenness under different storage conditions in green-kerneled rices, Saedongchalbyeo (Korea) and Hexi41 (China). Rough and brown-rice grains were stored just after harvest under different storage conditions; low (15℃) and room temperature storage, and light and dark storage at 21℃, 24℃, and 27℃. Kernel- greenness was measured by using colorimeter. When the grains were stored in brown rice at room temperature under light condition after harvest, kernel greenness was maintained up to 4 months and gradually faded away until 8 months. However, kernel greenness was maintained up to 10 months storage after harvest at room temperature under dark condition, and up to more than 11 months at low temperature under dark. Rough-rice grains kept the greenness up to more than 11 months regardless of the light and temperature. The higher the storage temperature, the less kernel-greenness when stored in brown rice. Light was the critical factor for degradation of kernel-greenness. For long-term storage of green-kerneled rices, rough-rice storage, or brown-rice storage under low-temperature and dark condition seemed to be desirable for the maintenance of kernel-greenness.